This document summarizes work analyzing data from observations of exoplanets using different shaped optical fibers. Code was developed to reduce images and plot line spread functions to determine which fiber most evenly scrambles starlight. Data from 2012 observations were analyzed for various star targets using 200um octagonal, 50um octagonal, rectangular, and square core fibers of 1m and 10m lengths. Standard deviations were calculated and some fibers showed consistency down to 1-2% while others ranged as high as 30%. The 50um octagonal fiber data on December 10th had the highest standard deviation of 16.89%.
Efficient charge transfer induced organic/inorganic based hybrid heterojunction of Ppy/GaN nanorods for high-performance self-powered UV photodetection
1) External irradiation from a broadband solid-state plasma light source was introduced to a laminar ethylene-air diffusion flame.
2) Soot samples extracted from different heights above the burner showed increases in soot volume fraction, primary particle diameter, and radius of gyration with external irradiation.
3) The dominant soot formation mechanism was found to transform from nucleation and coalescence to surface growth and agglomeration between heights of 20-30mm above the burner when external irradiation was applied.
IRJET- Optical Steering of Microbubbles for Nanoparticle TransportIRJET Journal
The document summarizes research on optically manipulating microbubbles and microbubbles coated with metallic nanoparticles. It begins with developing a theoretical model for the optical force on a microbubble in a laser beam based on induced dipoles. Experiments show microbubbles of different sizes are attracted to the laser beam center. The model is extended to microbubbles coated with nanoparticles, and experiments show nanoparticles have a negligible effect on manipulation. Optical steering of nanoparticle-surrounded microbubbles is demonstrated and could enable targeted drug delivery.
A thirty-four billion solar mass black hole in SMSS J2157–3602, the most lumi...Sérgio Sacani
From near-infrared spectroscopic measurements of the Mg II emission line doublet, we estimate the black hole (BH) mass of the quasar, SMSS J215728.21–360215.1, as being (3.4 ± 0.6) × 1010 M⊙ and refine the redshift of the quasar to be z = 4.692. SMSS J2157 is the most luminous known quasar, with a 3000 Å luminosity of (4.7 ± 0.5) × 1047 erg s−1 and an estimated bolometric luminosity of 1.6 × 1048 erg s−1 , yet its Eddington ratio is only ∼0.4. Thus, the high luminosity of this quasar is a consequence of its extremely large BH – one of the most massive BHs at z > 4.
A rare case of FR I interaction with a hot X-ray bridge in the A2384 galaxy c...Sérgio Sacani
Clusters of varying mass ratios can merge and the process significantly disturbs
the cluster environments and alters their global properties. Active radio galaxies are
another phenomenon that can also affect cluster environments. Radio jets can interact
with the intra-cluster medium (ICM) and locally affect its properties. Abell 2384
(hereafter A2384) is a unique system that has a dense, hot X-ray filament or bridge
connecting the two unequal mass clusters A2384(N) and A2384(S). The analysis of its
morphology suggests that A2384 is a post-merger system where A2384(S) has already
interacted with the A2384(N), and as a result hot gas has been stripped over a ∼ 1
Mpc region between the two bodies. We have obtained its 325 MHz GMRT data,
and we detected a peculiar FR I type radio galaxy which is a part of the A2384(S).
One of its radio lobes interacts with the hot X-ray bridge and pushes the hot gas in
the opposite direction. This results in displacement in the bridge close to A2384(S).
Based on Chandra and XMM-Newton X-ray observations, we notice a temperature and
entropy enhancement at the radio lobe-X-ray plasma interaction site, which further
suggests that the radio lobe is changing thermal plasma properties. We have also
studied the radio properties of the FR I radio galaxy, and found that the size and
radio luminosity of the interacting north lobe of the FR I galaxy are lower than those
of the accompanying south lobe.
Intra cluster light_at_the_frontier_abell_2744Sérgio Sacani
This document summarizes a study of the intra-cluster light (ICL) in the galaxy cluster Abell 2744 using deep Hubble Space Telescope images. The study finds that the ICL has bluer colors than the main galaxy members, indicating a younger average age of 6 billion years and lower metallicity. The ICL likely formed from the disruption of infalling galaxies similar to the Milky Way in mass and metallicity. The ICL comprises at least 6% of the total stellar mass in the central region of the cluster.
Drug delivery system based on gold nanostarsCarlos Maranje
This document summarizes a student's design of a photodelivery drug system using gold nanostars covered with polyacrylic acid modified with β-cyclodextrin. The system aims to have nanoparticles with strong near-infrared absorption and high light-to-heat conversion. β-cyclodextrin would store the drug (e.g. doxorubicin), and the coating would provide stability. The student's experiments show the system has over 90% drug loading capacity and can release 6% of the drug under near-infrared light irradiation.
Effect of Laser Induced Tin Oxide (SnO2) Nano particleIRJET Journal
The document summarizes a study on the effect of laser irradiation on tin oxide (SnO2) nanoparticles. Key findings include:
1) X-ray diffraction analysis showed the laser treated SnO2 has a tetragonal rutile crystalline structure with particle sizes ranging from 4-6nm.
2) UV-Vis spectroscopy found the optical band gap of the nanoparticles increased from 3.5eV to between 3.6-3.8eV with laser treatment.
3) FTIR spectroscopy revealed the presence of tin oxide and changes in vibrational bands with different laser treatments.
4) Dielectric studies and SEM/DLS analysis showed changes to particle size and properties with laser irradiation compared
Efficient charge transfer induced organic/inorganic based hybrid heterojunction of Ppy/GaN nanorods for high-performance self-powered UV photodetection
1) External irradiation from a broadband solid-state plasma light source was introduced to a laminar ethylene-air diffusion flame.
2) Soot samples extracted from different heights above the burner showed increases in soot volume fraction, primary particle diameter, and radius of gyration with external irradiation.
3) The dominant soot formation mechanism was found to transform from nucleation and coalescence to surface growth and agglomeration between heights of 20-30mm above the burner when external irradiation was applied.
IRJET- Optical Steering of Microbubbles for Nanoparticle TransportIRJET Journal
The document summarizes research on optically manipulating microbubbles and microbubbles coated with metallic nanoparticles. It begins with developing a theoretical model for the optical force on a microbubble in a laser beam based on induced dipoles. Experiments show microbubbles of different sizes are attracted to the laser beam center. The model is extended to microbubbles coated with nanoparticles, and experiments show nanoparticles have a negligible effect on manipulation. Optical steering of nanoparticle-surrounded microbubbles is demonstrated and could enable targeted drug delivery.
A thirty-four billion solar mass black hole in SMSS J2157–3602, the most lumi...Sérgio Sacani
From near-infrared spectroscopic measurements of the Mg II emission line doublet, we estimate the black hole (BH) mass of the quasar, SMSS J215728.21–360215.1, as being (3.4 ± 0.6) × 1010 M⊙ and refine the redshift of the quasar to be z = 4.692. SMSS J2157 is the most luminous known quasar, with a 3000 Å luminosity of (4.7 ± 0.5) × 1047 erg s−1 and an estimated bolometric luminosity of 1.6 × 1048 erg s−1 , yet its Eddington ratio is only ∼0.4. Thus, the high luminosity of this quasar is a consequence of its extremely large BH – one of the most massive BHs at z > 4.
A rare case of FR I interaction with a hot X-ray bridge in the A2384 galaxy c...Sérgio Sacani
Clusters of varying mass ratios can merge and the process significantly disturbs
the cluster environments and alters their global properties. Active radio galaxies are
another phenomenon that can also affect cluster environments. Radio jets can interact
with the intra-cluster medium (ICM) and locally affect its properties. Abell 2384
(hereafter A2384) is a unique system that has a dense, hot X-ray filament or bridge
connecting the two unequal mass clusters A2384(N) and A2384(S). The analysis of its
morphology suggests that A2384 is a post-merger system where A2384(S) has already
interacted with the A2384(N), and as a result hot gas has been stripped over a ∼ 1
Mpc region between the two bodies. We have obtained its 325 MHz GMRT data,
and we detected a peculiar FR I type radio galaxy which is a part of the A2384(S).
One of its radio lobes interacts with the hot X-ray bridge and pushes the hot gas in
the opposite direction. This results in displacement in the bridge close to A2384(S).
Based on Chandra and XMM-Newton X-ray observations, we notice a temperature and
entropy enhancement at the radio lobe-X-ray plasma interaction site, which further
suggests that the radio lobe is changing thermal plasma properties. We have also
studied the radio properties of the FR I radio galaxy, and found that the size and
radio luminosity of the interacting north lobe of the FR I galaxy are lower than those
of the accompanying south lobe.
Intra cluster light_at_the_frontier_abell_2744Sérgio Sacani
This document summarizes a study of the intra-cluster light (ICL) in the galaxy cluster Abell 2744 using deep Hubble Space Telescope images. The study finds that the ICL has bluer colors than the main galaxy members, indicating a younger average age of 6 billion years and lower metallicity. The ICL likely formed from the disruption of infalling galaxies similar to the Milky Way in mass and metallicity. The ICL comprises at least 6% of the total stellar mass in the central region of the cluster.
Drug delivery system based on gold nanostarsCarlos Maranje
This document summarizes a student's design of a photodelivery drug system using gold nanostars covered with polyacrylic acid modified with β-cyclodextrin. The system aims to have nanoparticles with strong near-infrared absorption and high light-to-heat conversion. β-cyclodextrin would store the drug (e.g. doxorubicin), and the coating would provide stability. The student's experiments show the system has over 90% drug loading capacity and can release 6% of the drug under near-infrared light irradiation.
Effect of Laser Induced Tin Oxide (SnO2) Nano particleIRJET Journal
The document summarizes a study on the effect of laser irradiation on tin oxide (SnO2) nanoparticles. Key findings include:
1) X-ray diffraction analysis showed the laser treated SnO2 has a tetragonal rutile crystalline structure with particle sizes ranging from 4-6nm.
2) UV-Vis spectroscopy found the optical band gap of the nanoparticles increased from 3.5eV to between 3.6-3.8eV with laser treatment.
3) FTIR spectroscopy revealed the presence of tin oxide and changes in vibrational bands with different laser treatments.
4) Dielectric studies and SEM/DLS analysis showed changes to particle size and properties with laser irradiation compared
This document presents a multiwavelength analysis of the merging galaxy cluster MACS J0416.1-2403 using observations from Chandra, JVLA, GMRT, and Hubble Space Telescope. The cluster consists of two main subclusters, NE and SW, separated by about 250 kpc. Chandra observations reveal the NE subcluster has a compact core and X-ray cavity, but is not a cool core. A density discontinuity is detected about 450 kpc southwest of the SW subcluster, likely caused by an interaction with a less massive structure detected in lensing maps. For both subclusters, the dark matter and gas components are well-aligned, suggesting MACS J0416.1-2403
Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287Sérgio Sacani
Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that the
next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31. This prediction
was based on detailed general relativistic modeling of the secondary BH trajectory around the primary
BH and its accretion disk. The expected flare was termed the Eddington flare to commemorate the
centennial celebrations of now-famous solar eclipse observations to test general relativity by Sir Arthur
Corresponding author: Lankeswar Dey
lankeswar.dey@tifr.res.in
arXiv:2004.13392v1 [astro-ph.HE] 28 Apr 2020
2 Laine et al.
Eddington. We analyze the multi-epoch Spitzer observations of the expected flare between 2019 July
31 and 2019 September 6, as well as baseline observations during 2019 February–March. Observed
Spitzer flux density variations during the predicted outburst time display a strong similarity with
the observed optical pericenter flare from OJ 287 during 2007 September. The predicted flare appears
comparable to the 2007 flare after subtracting the expected higher base-level Spitzer flux densities at
3.55 and 4.49 µm compared to the optical R-band. Comparing the 2019 and 2007 outburst lightcurves
and the previously calculated predictions, we find that the Eddington flare arrived within 4 hours of
the predicted time. Our Spitzer observations are well consistent with the presence of a nano-Hertz
gravitational wave emitting spinning massive binary BH that inspirals along a general relativistic
eccentric orbit in OJ 287. These multi-epoch Spitzer observations provide a parametric constraint
on the celebrated BH no-hair theorem.
This project uses computer simulations to model observations of the 2005 Deep Impact collision with comet Tempel 1. The simulations aim to understand the physics behind the light curves observed by Hubble Space Telescope. The simulations suggest the optically thick ejecta cloud was about 28 km in diameter 13 minutes after impact and expanding at around 36 m/s, constraining the cloud's mass to approximately 2x10^7 kg. This mass and expansion velocity are consistent with independent estimates from observations by different astronomy groups.
Mechanistic Investigation of FeO/MnO/ZnO Nanocomposites for UV Light Driven P...IRJET Journal
This document summarizes research on FeO/MnO/ZnO nanocomposites for photocatalytic performance under UV light. The nanocomposites (FMZ NCs) were prepared by ultrasonication assisted precipitation and analyzed using various characterization techniques. XRD analysis showed the FMZ NCs had a hexagonal wurtzite structure with an average crystalline size of 32 nm. SEM images revealed a spherical and flower-like morphology. UV-Vis spectroscopy showed the FMZ NCs had a decreased bandgap of 3.04 eV compared to undoped ZnO. Photoluminescence spectroscopy showed strong blue emission at 490 nm. Photocatalytic tests demonstrated the FMZ NCs achieved 91
The discovery of_lensed_radio_and_x-ray_sources_behind_the_frontier_fields_cl...Sérgio Sacani
We report on high-resolution JVLA and Chandra observations of the Hubble Space Telescope (HST) Frontier Cluster
MACSJ0717.5+3745. MACSJ0717.5+3745 offers the largest contiguous magnified area of any known cluster,
making it a promising target to search for lensed radio and X-ray sources. With the high-resolution 1.0–6.5 GHz
JVLA imaging in A and B configuration, we detect a total of 51 compact radio sources within the area covered by the
HST imaging. Within this sample, we find sevenlensed sources with amplification factors larger than two. None of
these sources are identified as multiply lensed. Based on the radio luminosities, the majority of these sources are
likely star-forming galaxies with star-formation rates (SFRs) of 10–50 M: yr−1 located at 1 1 z 1 2. Two of the
lensed radio sources are also detected in the Chandra image of the cluster. These two sources are likely active galactic
nuclei, given their 2–10 keV X-ray luminosities of ∼1043–44 erg s−1. From the derived radio luminosity function, we
find evidence for an increase in the number density of radio sources at 0.6 z 2.0, compared to a z 0.3 sample.
Our observations indicate that deep radio imaging of lensing clusters can be used to study star-forming galaxies, with
SFRs as low as ∼10Me yr−1, at the peak of cosmic star formation history.
The absorption spectrum of poly(3-hexylthiophene-2,5-diyl), or P3HT, shows a wide peak from 500-550 nm with a maximum at 526 nm corresponding to an energy of 2.36 eV. This peak is attributed to a 0-3' vibronic state. A shoulder is also observed from 590-610 nm with a critical point at 607 nm of 2.04 eV energy, likely due to a secondary vibronic excitation state. The peaks match those found in crystalline P3HT and are broader than solution spectra due to intermolecular interactions in the film.
Cation distribution of Ni2+ and Mg2+ ions improve structure and Magnetic Prop...AI Publications
In the present work, ferromagnetic Ni is slightly substituted for diamagnetic Mg spinal ferrites. The effect of Ni doping on the structural and magnetic properties of ferrites material in the form of NixMg1-xFe2O4 (x = 0.1,0.15,0.2,0.25, .0.3,0.35) has been the study. The Sol-gel auto Combustion method used to combine these substances uses urea as fuel. Sintered samples were shown using X-ray diffraction, Fourier Transform Infrared spectroscopy (FTIR) and a vibrating magnetometer sample. X-ray diffraction revealed that all the composite samples were pure cubic spinel arrays with a Fd3m space band and a permanent lattice that varied with Ni concentrations. the distribution of Ni2 + ions and Mg2+ ions in spinel ferrites indicates various changes in parameters such as tetrahedral ionic radius (rA), octahedral ionic radius (rB), hopping length (LA and LB). Fourier Transform Infrared (FT-IR) simulations showed wire vibration at the tetrahedral site and Octahedral site. spinel ferrites M-H curves are recorded at room temperature indicating normal hysteresis loop indicating the magnetic field.
Magnetic nanoparticles applications and bioavailability for cancer therapyPravin Chinchole
Magnetic nanoparticles can be used for cancer therapy applications. They can be coated or encapsulated to be bioavailable. When exposed to an external alternating magnetic field, the nanoparticles generate heat through hysteresis, friction, and relaxation effects. This localized hyperthermia can directly kill cancer cells or induce heat shock proteins to stimulate anti-cancer immunity. The nanoparticles can also be used for magnetic drug delivery, where drugs are attached and targeted to tumor sites using an external magnetic field, requiring lower doses than conventional treatment and reducing side effects. Studies have shown magnetic nanoparticle hyperthermia and drug delivery can significantly reduce tumor growth in animal models.
METAMATERIAL STRUCTURE FOR BANDWIDTH IMPROVEMENT Sayahnarahul
The document describes the design of a rectangular microstrip patch antenna operating at 1.881 GHz that uses a split rectangular shaped metamaterial structure to improve bandwidth. The metamaterial structure is designed on an FR-4 substrate and loaded onto the patch antenna. This is expected to increase the antenna's bandwidth to 22.5 MHz while reducing the return loss to -18.175 dB, compared to 4.9 MHz bandwidth and -10.068 dB return loss without the metamaterial. The metamaterial takes advantage of negative permeability to enhance the antenna performance.
Dense m agnetized_plasma_associated_with_afast_radio_burstSérgio Sacani
Astrônomos detectaram uma chamada rápida explosão de rádio a cerca de 6 bilhões de anos-luz de distância, uma das menos de duas dezenas desse tipo de evento descobertos nos últimos dez anos, e dessa vez eles têm pistas sobre a fonte.
As rápidas explosões de rádio, ou FRBs, são misteriosas explosões de energia que ocorrem no espaço e que aparecem como rápidos flashes de ondas de rádio nos telescópios da Terra. Essas explosões têm intrigado os astrônomos desde que elas foram reportadas pela primeira vez a uma década atrás. Embora somente 16 dessas explosões tenham sido registradas, eles acreditam que possam existir milhares delas por dia.
Vasculhando mais de 650 horas de dados obtidos pelo Telescópio Green Bank, do NRAO, um grupo internacional de astrônomos descobriu o mais detalhado registro já feito até hoje de uma FRB.
IRJET- Optical Properties of Copper Oxides (CuO) and Titanium Oxides (TiO2) N...IRJET Journal
This document discusses the optical properties of copper oxide (CuO) and titanium oxide (TiO2) nanoparticles for use in solar thermal systems. It investigates the nanoparticles' absorption, scattering, and extinction coefficients using Rayleigh's scattering model. The results show that CuO nanoparticles have high absorption and scattering coefficients in the UV range of 200-500nm wavelengths. While scattering decreases above 500nm, absorption remains significant, leading to high total extinction coefficients across the solar spectrum for CuO nanoparticles suspended at concentrations of 2PPM, 4PPM, and 6PPM.
Inference of homogeneous_clouds_in_an_exoplanet_atmosphereSérgio Sacani
1) New visible and infrared observations of the exoplanet Kepler-7b were analyzed to determine its atmospheric properties and detect the presence of clouds.
2) The observations found a westward shift in Kepler-7b's optical phase curve and placed upper limits on its thermal emission that remained undetected in Spitzer bandpasses.
3) The data suggests Kepler-7b has optically thick, high-altitude clouds located west of the substellar point, composed possibly of silicates. The clouds help explain Kepler-7b's unusually high geometric albedo and visible flux that cannot be attributed to thermal emission or molecular hydrogen scattering alone.
Study of magnetic and structural and optical properties of Zn doped Fe3O4 nan...Nanomedicine Journal (NMJ)
Objective(s):
This paper describes synthesizing of magnetic nanocomposite with co-precipitation
method.
Materials and Methods:
Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy.
Results:
results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV.
Conclusion:
These magnetic nanocomposite structures since having superparamagnetic property
offer a high potential for biosensing and biomedical application.
Structural Health Monitoring Aluminum Honeycomb Sandwich Composite PanelDawid Yhisreal
NASA evaluated using fiber Bragg gratings (FBG) embedded in honeycomb sandwich carbon composite panels as impact sensors to detect damage. An FBG sensor was embedded in a panel between the face-sheet and core. Impacts of 1 ft-lb were made at one-inch intervals and data was collected from the FBG and acoustic emission sensors. Results showed that FBG sensors could successfully detect impacts and have benefits over traditional sensors by enabling strain measurement and eliminating needs for additional systems.
1) Carbon nanotube fibers can be used as broadband photodetectors due to their mechanical strength, electrical conductivity, thermal conductivity, and ability to absorb light across a wide electromagnetic spectrum.
2) Two types of photodetectors were fabricated from the fibers: double-fiber devices using two interconnected fibers, and single-fiber devices using half of one fiber.
3) Testing showed the photodetectors generated a photovoltage in response to laser excitation due to the Seebeck effect from heat produced, and performance depended on factors like doping, wavelength, and position along the fiber.
Ke Li has over 12 years of experience in optics, lasers, and atomic physics research. He is currently a research fellow at Nanyang Technological University studying defect inspection in semiconductors using a home-built confocal microscope and isolating single defects for quantum information applications. Previously he has held positions at the National University of Singapore, National Institute of Standards and Technology, and Wuhan Institute of Physics and Mathematics, conducting research on topics including laser cooling and trapping of atoms, Bose-Einstein condensation, and optical lattices.
A spectroscopic redshift_measurement_for_a_luminous_lyman_break_galaxy_at_z _...Sérgio Sacani
This document presents the spectroscopic confirmation of a luminous Lyman break galaxy (LBG) at a redshift of z = 7.7302 ± 0.0006, as observed using the MOSFIRE instrument on the Keck I telescope. The galaxy, named EGS-zs8-1, was pre-selected as a promising candidate for spectroscopic follow-up based on its bright apparent magnitude of H = 25.0 and very red Spitzer/IRAC colors suggestive of strong emission lines. Spectroscopic observations revealed a clear detection of the Lyman-alpha emission line at a observed wavelength of 1.06 microns, reliably confirming the high photometric redshift of z~7.7. Analysis of the
1. The document describes observations of the Seyfert-1 galaxy Mrk 509 using XMM-Newton and Swift.
2. It analyzes the optical-UV and X-ray variability over a 100 day monitoring campaign with a few day resolution.
3. The results suggest that on these timescales, the soft X-ray excess in Mrk 509 is produced by warm Comptonization of thermal optical-UV photons from the accretion disk by a warm, optically thick corona surrounding the inner disk regions.
A mathematical algorithm was developed to calculate effective density values within Apollo lunar core samples using digitized radiographs. Code was written in MATLAB to produce density maps based on the algorithm. Factors like varying X-ray intensities due to the Inverse Square Law and different material thicknesses were accounted for. The resulting density maps provide reasonable values compared to previously measured bulk densities, but more information is needed to address issues in radiography and the physical parameters of the X-ray setup. With this additional information, density values as a function of depth and porosity can be accurately evaluated.
1. This document describes a multiwavelength campaign on the Seyfert 1 galaxy Mrk 509 using five satellites and two ground-based facilities.
2. The campaign aims to study several open questions about active galactic nuclei (AGN), including the location and physics of outflows from AGN, the nature of continuum emission, the geometry and physical state of the X-ray broad emission line region, and the Fe-K line complex.
3. The observations cover more than five decades in frequency, from 2 μm to 200 keV, and include a simultaneous set of deep XMM-Newton and INTEGRAL observations over seven weeks. This allows the authors to disentangle different components and study time variability
This document presents a multiwavelength analysis of the merging galaxy cluster MACS J0416.1-2403 using observations from Chandra, JVLA, GMRT, and Hubble Space Telescope. The cluster consists of two main subclusters, NE and SW, separated by about 250 kpc. Chandra observations reveal the NE subcluster has a compact core and X-ray cavity, but is not a cool core. A density discontinuity is detected about 450 kpc southwest of the SW subcluster, likely caused by an interaction with a less massive structure detected in lensing maps. For both subclusters, the dark matter and gas components are well-aligned, suggesting MACS J0416.1-2403
Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287Sérgio Sacani
Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that the
next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31. This prediction
was based on detailed general relativistic modeling of the secondary BH trajectory around the primary
BH and its accretion disk. The expected flare was termed the Eddington flare to commemorate the
centennial celebrations of now-famous solar eclipse observations to test general relativity by Sir Arthur
Corresponding author: Lankeswar Dey
lankeswar.dey@tifr.res.in
arXiv:2004.13392v1 [astro-ph.HE] 28 Apr 2020
2 Laine et al.
Eddington. We analyze the multi-epoch Spitzer observations of the expected flare between 2019 July
31 and 2019 September 6, as well as baseline observations during 2019 February–March. Observed
Spitzer flux density variations during the predicted outburst time display a strong similarity with
the observed optical pericenter flare from OJ 287 during 2007 September. The predicted flare appears
comparable to the 2007 flare after subtracting the expected higher base-level Spitzer flux densities at
3.55 and 4.49 µm compared to the optical R-band. Comparing the 2019 and 2007 outburst lightcurves
and the previously calculated predictions, we find that the Eddington flare arrived within 4 hours of
the predicted time. Our Spitzer observations are well consistent with the presence of a nano-Hertz
gravitational wave emitting spinning massive binary BH that inspirals along a general relativistic
eccentric orbit in OJ 287. These multi-epoch Spitzer observations provide a parametric constraint
on the celebrated BH no-hair theorem.
This project uses computer simulations to model observations of the 2005 Deep Impact collision with comet Tempel 1. The simulations aim to understand the physics behind the light curves observed by Hubble Space Telescope. The simulations suggest the optically thick ejecta cloud was about 28 km in diameter 13 minutes after impact and expanding at around 36 m/s, constraining the cloud's mass to approximately 2x10^7 kg. This mass and expansion velocity are consistent with independent estimates from observations by different astronomy groups.
Mechanistic Investigation of FeO/MnO/ZnO Nanocomposites for UV Light Driven P...IRJET Journal
This document summarizes research on FeO/MnO/ZnO nanocomposites for photocatalytic performance under UV light. The nanocomposites (FMZ NCs) were prepared by ultrasonication assisted precipitation and analyzed using various characterization techniques. XRD analysis showed the FMZ NCs had a hexagonal wurtzite structure with an average crystalline size of 32 nm. SEM images revealed a spherical and flower-like morphology. UV-Vis spectroscopy showed the FMZ NCs had a decreased bandgap of 3.04 eV compared to undoped ZnO. Photoluminescence spectroscopy showed strong blue emission at 490 nm. Photocatalytic tests demonstrated the FMZ NCs achieved 91
The discovery of_lensed_radio_and_x-ray_sources_behind_the_frontier_fields_cl...Sérgio Sacani
We report on high-resolution JVLA and Chandra observations of the Hubble Space Telescope (HST) Frontier Cluster
MACSJ0717.5+3745. MACSJ0717.5+3745 offers the largest contiguous magnified area of any known cluster,
making it a promising target to search for lensed radio and X-ray sources. With the high-resolution 1.0–6.5 GHz
JVLA imaging in A and B configuration, we detect a total of 51 compact radio sources within the area covered by the
HST imaging. Within this sample, we find sevenlensed sources with amplification factors larger than two. None of
these sources are identified as multiply lensed. Based on the radio luminosities, the majority of these sources are
likely star-forming galaxies with star-formation rates (SFRs) of 10–50 M: yr−1 located at 1 1 z 1 2. Two of the
lensed radio sources are also detected in the Chandra image of the cluster. These two sources are likely active galactic
nuclei, given their 2–10 keV X-ray luminosities of ∼1043–44 erg s−1. From the derived radio luminosity function, we
find evidence for an increase in the number density of radio sources at 0.6 z 2.0, compared to a z 0.3 sample.
Our observations indicate that deep radio imaging of lensing clusters can be used to study star-forming galaxies, with
SFRs as low as ∼10Me yr−1, at the peak of cosmic star formation history.
The absorption spectrum of poly(3-hexylthiophene-2,5-diyl), or P3HT, shows a wide peak from 500-550 nm with a maximum at 526 nm corresponding to an energy of 2.36 eV. This peak is attributed to a 0-3' vibronic state. A shoulder is also observed from 590-610 nm with a critical point at 607 nm of 2.04 eV energy, likely due to a secondary vibronic excitation state. The peaks match those found in crystalline P3HT and are broader than solution spectra due to intermolecular interactions in the film.
Cation distribution of Ni2+ and Mg2+ ions improve structure and Magnetic Prop...AI Publications
In the present work, ferromagnetic Ni is slightly substituted for diamagnetic Mg spinal ferrites. The effect of Ni doping on the structural and magnetic properties of ferrites material in the form of NixMg1-xFe2O4 (x = 0.1,0.15,0.2,0.25, .0.3,0.35) has been the study. The Sol-gel auto Combustion method used to combine these substances uses urea as fuel. Sintered samples were shown using X-ray diffraction, Fourier Transform Infrared spectroscopy (FTIR) and a vibrating magnetometer sample. X-ray diffraction revealed that all the composite samples were pure cubic spinel arrays with a Fd3m space band and a permanent lattice that varied with Ni concentrations. the distribution of Ni2 + ions and Mg2+ ions in spinel ferrites indicates various changes in parameters such as tetrahedral ionic radius (rA), octahedral ionic radius (rB), hopping length (LA and LB). Fourier Transform Infrared (FT-IR) simulations showed wire vibration at the tetrahedral site and Octahedral site. spinel ferrites M-H curves are recorded at room temperature indicating normal hysteresis loop indicating the magnetic field.
Magnetic nanoparticles applications and bioavailability for cancer therapyPravin Chinchole
Magnetic nanoparticles can be used for cancer therapy applications. They can be coated or encapsulated to be bioavailable. When exposed to an external alternating magnetic field, the nanoparticles generate heat through hysteresis, friction, and relaxation effects. This localized hyperthermia can directly kill cancer cells or induce heat shock proteins to stimulate anti-cancer immunity. The nanoparticles can also be used for magnetic drug delivery, where drugs are attached and targeted to tumor sites using an external magnetic field, requiring lower doses than conventional treatment and reducing side effects. Studies have shown magnetic nanoparticle hyperthermia and drug delivery can significantly reduce tumor growth in animal models.
METAMATERIAL STRUCTURE FOR BANDWIDTH IMPROVEMENT Sayahnarahul
The document describes the design of a rectangular microstrip patch antenna operating at 1.881 GHz that uses a split rectangular shaped metamaterial structure to improve bandwidth. The metamaterial structure is designed on an FR-4 substrate and loaded onto the patch antenna. This is expected to increase the antenna's bandwidth to 22.5 MHz while reducing the return loss to -18.175 dB, compared to 4.9 MHz bandwidth and -10.068 dB return loss without the metamaterial. The metamaterial takes advantage of negative permeability to enhance the antenna performance.
Dense m agnetized_plasma_associated_with_afast_radio_burstSérgio Sacani
Astrônomos detectaram uma chamada rápida explosão de rádio a cerca de 6 bilhões de anos-luz de distância, uma das menos de duas dezenas desse tipo de evento descobertos nos últimos dez anos, e dessa vez eles têm pistas sobre a fonte.
As rápidas explosões de rádio, ou FRBs, são misteriosas explosões de energia que ocorrem no espaço e que aparecem como rápidos flashes de ondas de rádio nos telescópios da Terra. Essas explosões têm intrigado os astrônomos desde que elas foram reportadas pela primeira vez a uma década atrás. Embora somente 16 dessas explosões tenham sido registradas, eles acreditam que possam existir milhares delas por dia.
Vasculhando mais de 650 horas de dados obtidos pelo Telescópio Green Bank, do NRAO, um grupo internacional de astrônomos descobriu o mais detalhado registro já feito até hoje de uma FRB.
IRJET- Optical Properties of Copper Oxides (CuO) and Titanium Oxides (TiO2) N...IRJET Journal
This document discusses the optical properties of copper oxide (CuO) and titanium oxide (TiO2) nanoparticles for use in solar thermal systems. It investigates the nanoparticles' absorption, scattering, and extinction coefficients using Rayleigh's scattering model. The results show that CuO nanoparticles have high absorption and scattering coefficients in the UV range of 200-500nm wavelengths. While scattering decreases above 500nm, absorption remains significant, leading to high total extinction coefficients across the solar spectrum for CuO nanoparticles suspended at concentrations of 2PPM, 4PPM, and 6PPM.
Inference of homogeneous_clouds_in_an_exoplanet_atmosphereSérgio Sacani
1) New visible and infrared observations of the exoplanet Kepler-7b were analyzed to determine its atmospheric properties and detect the presence of clouds.
2) The observations found a westward shift in Kepler-7b's optical phase curve and placed upper limits on its thermal emission that remained undetected in Spitzer bandpasses.
3) The data suggests Kepler-7b has optically thick, high-altitude clouds located west of the substellar point, composed possibly of silicates. The clouds help explain Kepler-7b's unusually high geometric albedo and visible flux that cannot be attributed to thermal emission or molecular hydrogen scattering alone.
Study of magnetic and structural and optical properties of Zn doped Fe3O4 nan...Nanomedicine Journal (NMJ)
Objective(s):
This paper describes synthesizing of magnetic nanocomposite with co-precipitation
method.
Materials and Methods:
Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy.
Results:
results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV.
Conclusion:
These magnetic nanocomposite structures since having superparamagnetic property
offer a high potential for biosensing and biomedical application.
Structural Health Monitoring Aluminum Honeycomb Sandwich Composite PanelDawid Yhisreal
NASA evaluated using fiber Bragg gratings (FBG) embedded in honeycomb sandwich carbon composite panels as impact sensors to detect damage. An FBG sensor was embedded in a panel between the face-sheet and core. Impacts of 1 ft-lb were made at one-inch intervals and data was collected from the FBG and acoustic emission sensors. Results showed that FBG sensors could successfully detect impacts and have benefits over traditional sensors by enabling strain measurement and eliminating needs for additional systems.
1) Carbon nanotube fibers can be used as broadband photodetectors due to their mechanical strength, electrical conductivity, thermal conductivity, and ability to absorb light across a wide electromagnetic spectrum.
2) Two types of photodetectors were fabricated from the fibers: double-fiber devices using two interconnected fibers, and single-fiber devices using half of one fiber.
3) Testing showed the photodetectors generated a photovoltage in response to laser excitation due to the Seebeck effect from heat produced, and performance depended on factors like doping, wavelength, and position along the fiber.
Ke Li has over 12 years of experience in optics, lasers, and atomic physics research. He is currently a research fellow at Nanyang Technological University studying defect inspection in semiconductors using a home-built confocal microscope and isolating single defects for quantum information applications. Previously he has held positions at the National University of Singapore, National Institute of Standards and Technology, and Wuhan Institute of Physics and Mathematics, conducting research on topics including laser cooling and trapping of atoms, Bose-Einstein condensation, and optical lattices.
A spectroscopic redshift_measurement_for_a_luminous_lyman_break_galaxy_at_z _...Sérgio Sacani
This document presents the spectroscopic confirmation of a luminous Lyman break galaxy (LBG) at a redshift of z = 7.7302 ± 0.0006, as observed using the MOSFIRE instrument on the Keck I telescope. The galaxy, named EGS-zs8-1, was pre-selected as a promising candidate for spectroscopic follow-up based on its bright apparent magnitude of H = 25.0 and very red Spitzer/IRAC colors suggestive of strong emission lines. Spectroscopic observations revealed a clear detection of the Lyman-alpha emission line at a observed wavelength of 1.06 microns, reliably confirming the high photometric redshift of z~7.7. Analysis of the
1. The document describes observations of the Seyfert-1 galaxy Mrk 509 using XMM-Newton and Swift.
2. It analyzes the optical-UV and X-ray variability over a 100 day monitoring campaign with a few day resolution.
3. The results suggest that on these timescales, the soft X-ray excess in Mrk 509 is produced by warm Comptonization of thermal optical-UV photons from the accretion disk by a warm, optically thick corona surrounding the inner disk regions.
A mathematical algorithm was developed to calculate effective density values within Apollo lunar core samples using digitized radiographs. Code was written in MATLAB to produce density maps based on the algorithm. Factors like varying X-ray intensities due to the Inverse Square Law and different material thicknesses were accounted for. The resulting density maps provide reasonable values compared to previously measured bulk densities, but more information is needed to address issues in radiography and the physical parameters of the X-ray setup. With this additional information, density values as a function of depth and porosity can be accurately evaluated.
1. This document describes a multiwavelength campaign on the Seyfert 1 galaxy Mrk 509 using five satellites and two ground-based facilities.
2. The campaign aims to study several open questions about active galactic nuclei (AGN), including the location and physics of outflows from AGN, the nature of continuum emission, the geometry and physical state of the X-ray broad emission line region, and the Fe-K line complex.
3. The observations cover more than five decades in frequency, from 2 μm to 200 keV, and include a simultaneous set of deep XMM-Newton and INTEGRAL observations over seven weeks. This allows the authors to disentangle different components and study time variability
This proposal seeks funding to develop laser-based optical trapping, or "tractor beams", for remote sampling of particles in space. Tractor beams could non-invasively collect samples from comets, asteroids, planetary atmospheres and surfaces. This would enable new types of sampling missions without landers or sample return. The proposal outlines developing tractor beam technology through lab experiments and scaling it for potential applications on spacecraft. Developing tractor beams could significantly expand NASA's capability to remotely collect and analyze samples throughout the solar system.
Optical Properties of Mesoscopic Systems of Coupled MicrospheresShashaanka Ashili
Two mechanisms of optical coupling between spherical cavities, tight-binding between their whispering gallery modes and focusing produced by periodically coupled microlenses, are directly observed using spatially resolved scattering spectroscopy and imaging. The results can be used for developing device concepts of lasers, optical filters, microspectrometers and sensors based on mesoscopic systems of coupled microspheres.
This document discusses various characterization techniques for nanoparticles. It describes microscopy methods like scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning tunneling microscopy (STM) that can be used to determine nanoparticle size, shape, composition and crystalline structure at high resolution. Spectroscopy methods like X-ray diffraction (XRD), small angle X-ray scattering (SAXS), X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, and Fourier transform infrared spectroscopy (FT-IR) are also outlined for analyzing nanoparticle properties. The key techniques of SEM, TEM, XRD and SAXS are then explained in more detail regarding their basic principles and what types of nanoparticle information can be obtained
Synthesis, Growth and Characterization of Nonlinear Optical Semi Organic Pota...IRJET Journal
The document summarizes the synthesis, growth, and characterization of Potassium Sulphate Formate (PSF) single crystals grown by slow evaporation method. PSF crystals were grown by dissolving equimolar ratios of Potassium Sulphate and Formic acid in water. Single crystal XRD analysis confirmed the crystals belong to the orthorhombic system with space group Pna21. Powder XRD and FTIR analysis verified the crystallinity and functional groups. UV-Vis spectroscopy determined the optical transmission range and bandgap. Thermal analysis and SHG measurements showed the crystals have good thermal stability and higher SHG efficiency than KDP.
1. The document describes the Fluorescence detector Array of Single-pixel Telescopes (FAST) project, which aims to develop an economical fluorescence detector array to detect ultra-high energy cosmic rays and neutral particles.
2. A full-scale FAST prototype is being constructed and tested. It is expected to be installed at the Telescope Array experiment site in Utah in June 2016 to perform calibration and cross-checks with the existing detectors.
3. Preliminary simulations show that the combined analysis of data from FAST and the surface detector array could provide an energy resolution of 10% and an Xmax resolution of 35 g/cm2 for protons at 10^19.5 eV.
Calculation of Optical Properties of Nano ParticlePHYSICS 5535- .docxRAHUL126667
Calculation of Optical Properties of Nano Particle
PHYSICS 5535- Optical Properties Matter-Spring 2017
Raznah Yami
Outline
1. Introduction: this part gives a precise overview of the whole paper. It begins by illustrating a brief introduction and importance of Nano Particles and the theoretical approaches used for their calculation.
2. Main idea: this section provides a step-by-step in-depth analysis of recently developed theories the calculation of optical properties of nanoparticles. It also provides calculation and equations employed these approaches.
2.1 Optical Properties of Nanoparticles: this section talks about the basics principles and governing the optical behavior of Nano particles and provides in-depth knowledge of different phenomena observed while dealing with optical properties of Nano particles.
2.2 Mie-Theory: the research provides exhaustive information the study optical properties of nanoparticles using Mie theory. This research focuses on Mie theory for the calculation of optical properties of Nano particle according to which we can calculate the place of surface Plasmon resonance in optical spectra of metallic spherical nanoparticle.
2.3 Discrete Dipole Approximation method: this section enumerates sufficient information about the calculation of absorption and scattering efficiencies and optical resonance wavelengths for three commonly used classes of nanoparticles: gold Nano spheres, silica-gold Nano shells, and gold Nano rods and we examine the magneto-optical scattering from nanometer-scale structures using a discrete dipole approximation.
3. Conclusion: This section provides a summary of the most important points, which presents an overview of the practical application and calculation methods of optical properties of Nano particles talking about core principles, which therefore explain the behavior exhibited by nanoparticles.
List of figures:
Figure 1: Localized surface Plasmon resonance ,resulting from the collective oscillations of delocalized electrons in response to an external electric field
Figure 2: Absorption spectra of semiconductor nanoparticles of different diameter. Right-nanoparticles suspended in solution.
Figure 3: Comparison of absorbance along increasing wavelength between Nano GaAs (7-15 nm) and Bulk GaAs showing an apparent blue shift
Figure 4: Showing the effect of blue shift because of quantum confinement as the wavelength shifts from 1100 nm to 2000 nm when we move from particle size of 9nm to parcile size of 3 nm.
Figure 5: Emission spectra of several sizes of (Cdse) Zns core-shell quantum dots.
Figure 6: The optical spectra and transmission electron micrographs for the particles in vials 1–5 are also shown. Scale bars in micrographs are all 100 nm
Figure7: Shows the effect of varying relative core and shell thickness of gold Nano Shells, there is an apparent blue shift as the frequency increases
References:
1. . P. S. Per ...
How do engines make a gps for the milky way possibleBurraqITSloution
The Moons project aims to map the Milky Way galaxy in 3D by using a new spectrograph instrument called Moons installed on the Very Large Telescope in Chile. Moons will be able to simultaneously observe the spectra of 1,001 astronomical objects, providing more detailed information about their composition and motion than images alone. This will allow astronomers to see deeper into the galaxy and create the first comprehensive 3D map of the Milky Way, functioning like a "GPS" for navigation within the galaxy. Key to Moons' ability to precisely position its 1,001 optical fibers is the use of high-precision stepper motors and gears from Faulhaber, without which the project would not be possible. Moons is expected to
This document summarizes new results from a study of proper motions in the optical jet of the galaxy M87 using over 13 years of Hubble Space Telescope imaging data. Key findings include:
1) Superluminal velocities (above the speed of light) were measured for knots as far out as knot C in the jet, suggesting these speeds persist over large distances.
2) Significant apparent accelerations both parallel and transverse to the jet axis were found, as well as evidence for stationary features in some knots.
3) Complex motions including differing velocities between nearby features and changes in velocity over time were observed throughout the jet, placing constraints on theoretical jet models.
This document summarizes the calibration of the broadband photometric system for the RCT 1.3-meter Robotic Telescope. It finds that the linear color transformations and extinction corrections are consistent with similar KPNO facilities, with a photometric precision of 10% at 1 sigma. Some instrumental errors were identified that likely contributed to the overall uncertainty, related to engineering and maintenance issues for the new robotic facility. A preliminary verification showed the calibration solution is robust, perhaps to a higher precision than indicated by the initial calibration. The RCT has been executing regular science operations since 2009.
Electron Diffraction Using Transmission Electron MicroscopyLe Scienze Web News
Electron diffraction via the transmission electron microscope is a powerful method for characterizing the structure of materials, including perfect crystals and defect structures. The advantages of elec- tron diffraction over other methods, e.g., x-ray or neutron, arise from the extremely short wavelength (≈2 pm), the strong atomic scattering, and the ability to exam- ine tiny volumes of matter (≈10 nm3). The NIST Materials Science and Engineer- ing Laboratory has a history of discovery and characterization of new structures through electron diffraction, alone or in combination with other diffraction methods. This paper provides a survey of some of this work enabled through electron mi- croscopy.
The muse 3_d_view_of_the_hubble_deep_field_southSérgio Sacani
Artigo mostra como foram as observações feitas com o MUSE, o novo instrumento do VLT do campo profundo do Hubble. Além de descobrir 20 novos objetos, o MUSE conseguiu medir as propriedades das galáxias e até representar as mais próximas em 3 dimensões.
Orbital configurations of spaceborne interferometers for studying photon ring...Sérgio Sacani
Recent advances in technology coupled with the progress of observational
radio astronomy methods resulted in achieving a major milestone of astrophysics - a direct image of the shadow of a supermassive black hole, taken
by the Earth-based Event Horizon Telescope (EHT). The EHT was able to
achieve a resolution of ∼20 µas, enabling it to resolve the shadows of the
black holes in the centres of two celestial objects: the supergiant elliptical
galaxy M87 and the Milky Way Galaxy. The EHT results mark the start of a
new round of development of next generation Very Long Baseline Interferometers (VLBI) which will be able to operate at millimetre and sub-millimetre
wavelengths. The inclusion of baselines exceeding the diameter of the Earth
and observation at as short a wavelength as possible is imperative for further development of high resolution astronomical observations. This can be
achieved by a spaceborne VLBI system. We consider the preliminary mission
design of such a system, specifically focused on the detection and analysis
of photon rings, an intrinsic feature of supermassive black holes. Optimised
Earth, Sun-Earth L2 and Earth-Moon L2 orbit configurations for the space
interferometer system are presented, all of which provide an order of magnitude improvement in resolution compared to the EHT. Such a space-borne
The Internal Structure of Asteroid (25143) Itokawa as Revealed by Detection o...WellingtonRodrigues2014
- The authors detected an acceleration in the rotation rate of asteroid (25143) Itokawa through photometric observations spanning 2001 to 2013.
- By measuring rotational phase offsets between observed and modeled lightcurves, they found a YORP acceleration of 3.54 ± 0.38 × 10−8 rad day−2, equivalent to a decrease in the asteroid's rotation period of about 45 ms per year.
- Thermophysical modeling of the detailed shape model from the Hayabusa spacecraft could not reconcile the observed YORP strength unless the asteroid's center of mass is shifted by about 21 m along its long axis. This suggests Itokawa has two components with different densities that merged, either from a
The internal structure_of_asteroid_itokawa_as_revealed_by_detection_of_yorp_s...Sérgio Sacani
The study detected an acceleration in the rotation rate of asteroid (25143) Itokawa through long-term photometric monitoring between 2001-2013. By measuring rotational phase offsets between observed and modeled lightcurves, a YORP acceleration of 3.54 ± 0.38 × 10−8 rad day−2 was measured, equivalent to a decrease in the asteroid's rotation period of about 45 ms per year. Thermophysical analysis of the detailed shape model from the Hayabusa spacecraft found that the center-of-mass must be offset by about 21 m along the long axis to reconcile the observed and theoretical YORP strengths, suggesting Itokawa is composed of two separate bodies with densities of 1750 ± 110 kg m
A multi wavelength_analysis_of_m8_insight_on_the_nature_of_arp_loopSérgio Sacani
This document presents a multi-wavelength analysis of M81 and Arp's loop, a peculiar ring-like structure around M81. Optical images reveal Arp's loop has a filamentary structure with many overlapping dust features. Infrared images show Arp's loop has infrared colors and emission properties similar to Galactic cirrus clouds in the region. The results suggest the light at optical wavelengths comes from recent star formation near M81, M81's extended disk, and scattered light from Galactic cirrus, while the infrared emission is dominated by cold dust from Galactic cirrus.
1) The study aims to create a funduscope (adapted from Schejter et al.'s design) to non-invasively image fluorescent retinal ganglion cells in vivo through the pupil of rodents. This would help determine if viruses used to make the cells fluorescent have properly infected them.
2) Components of the funduscope include an endoscope, fiber optic cables, filters, and camera. Various components were considered, including the type of endoscope, fiber, filters, and light source.
3) Testing showed the funduscope was able to provide high-quality fluorescence images of retinal ganglion cells in vivo, which could help researchers evaluate experiments without sacrificing test animals.
The document describes a proposed design for trapping and imaging rubidium-85 ions using near-field scanning optical microscopy techniques. The design involves using three orthogonal laser beams to form an optical molasses trap for cooling rubidium ions. This trap will be assisted by an anti-Helmholtz coil pair to create a magneto-optical trap. Tapered optical fibers etched with hydrofluoric acid will be used as probes in near-field scanning optical microscopy to detect and image the trapped ions with high resolution. Fluorescence detection of the trapped ions will aim to optimize the signal-to-noise ratio using lock-in amplification.
1. The document discusses various methods used to investigate the structure of fibers, including nuclear magnetic resonance, infrared spectroscopy, optical and x-ray diffraction, thermal analysis, optical microscopy, electron microscopy, and density measurement.
2. It provides details on specific techniques like nuclear magnetic resonance spectroscopy, optical diffraction, x-ray diffraction, and electron microscopy and electron diffraction. These techniques help determine properties of fibers like composition, molecular structure, crystallinity, and orientation.
3. The structure investigation of fibers is important to understand fiber properties in order to improve their use in textiles. Different methods are used to study characteristics like chemical bonding, molecular spacing, and cross-sectional structure.
Similar to Image Reduction Programs for Non-Circular Core Fiber Scrambler (20)
Image Reduction Programs for Non-Circular Core Fiber Scrambler
1. PHY 486: Image Reduction Programs for Non-Circular Core Fiber Scrambler
Joseph M. Regan
Department of Physics, Astronomy, and Materials Science
Missouri State University
Dr. Peter Plavchan, Advisor
Abstract
Over four months in 2012, data was obtained of several exoplanet candidates using the
CSHELL spectrograph at the peak of Mauna Kea in Hawaii, along with Dr. Peter Plavchan’s
Non-Circular Core Fiber Scrambler. Images and spectra were obtained in near-infrared
wavelengths using different shaped (non-circular) core fibers for the purpose of detecting
exoplanetsusingthe radial velocitymethod. Sincethen,code hasbeendevelopedinorderto
reduce the images using dark images, flat images, and bias images taken at the same time.
Code has also been developed to plot a line-spread function of the pixel intensity of sets of
images taken using the different fibers with respect to their position. These two programs,
used in tandem on Missouri State University’s high performance computing cluster (also
known as Exo), have been used to determine which fiber, between a 200 micron diameter
square fiber, 50 and 200 micron diameter variantsof octagonal fibers,and a 50x100 micron
rectangularfiber,mostevenlyandconsistentlyscramblesthelightfromthe targetstarswhen
shone through one end of the fiber.
1 – Introduction
In the field of Astronomy, the search for extrasolar planets, or Exoplanets, has boomed in the
last decade or so, due to increasingly efficient methods of detecting them around other stars.
At the time of this writing, we have discovered a total of more than 1800 exoplanets, with over
4000 more waiting to be confirmed3. There are many ways of detecting these planets, but the
two most successful methods of planet detection are the transit method, watching a star’s light
dim periodically as the planet passes in front of it, and the radial velocity method, observing the
red- and blue-shifting of a star as it and a planet orbit a common center of mass. The former
method has been more successful overall, with the Kepler space telescope discovering and
confirming over a thousand of the total confirmed exoplanets using the transit method. This
method is tricky, since it requires a planet and its parent star to be lined up with our field of
vision. Using this method, usually we can find short-period large-radius planets2.
In any planetary system, it appears due to the vast difference in mass that the planet orbits the
star, but instead, the star and the planet orbit a common barycenter, obeying Kepler’s laws of
planetary motion. Due to the planet’s gravitational effect, the star will move ever so slightly
around this barycenter, causing a slight shift in the spectrum of the star. If this slight movement
can be isolated in the spectrum, we can determine the exact radial velocity of the star, and the
orbital period and mass of the planet can be measured. These measurements have been taken
in optical wavelengths, and at the time of this writing, 533 planets have been confirmed using
this method3. However, no measurements have yet been made in the near-infrared, which may
allow us to locate far more exoplanets than are currently confirmed.
2. 2 – Non-Circular Core Fiber Scrambler
Dr. Plavchan’s non-circular core fiber scrambler takes precision spectroscopic radial velocity
measurements in the near-infrared H band. Tests using the fibers were collected in the near-
infrared at H and K bands using the CSHELL spectrograph at the NASA InfraRed Telescope
Facility (IRTF) at the peak of Mauna Kea in Hawaii. CSHELL, a near-20-year-old spectrograph,
covers wavelengths from 1 to 5.5 µm. Parts of CSHELL were modified to accommodate the
prototype fiber scrambler. One added part is an absorption gas cell between two of the mirrors,
used for a common optical path relative wavelength calibration. The gas cell is filled with
isotopic methane (13CH4) at 275mb of pressure, which in both the H and K bands, leaves a sharp
set of absorption lines in the near-infrared. These lines help calibrate the spectrograph,
accounting for isotopic methane in the atmosphere that may interfere with the stellar spectra.
The fiber scrambler operates, in principle, by running the starlight from the telescope through
the fiber input, then relaying the output to the spectrograph slit input. Fibers used for the
scrambler were octagonal and square core fibers 200µm in diameter and 1 and 10m in length,
rectangular core fibers 50x100µm in diameter and 1 and 10m in length, and octagonal core
fibers 50 microns in diameter 1 and 10m in length1.
Figure 1. Images ofstarlightthroughfiber tips in near-infrared. From left to right: 200µmoctagonalcore,1 and 10m length, 50µmsquarecore
fiber, 50x100µmrectangular corefiber, 50µmoctagonalcorefiber.
Figure 2. Images of theFiberScrambler.On theright, the setupofthe lenses insidethescramblerbefore finalconstruction; on theleft, the
completed fiberscrambler inits aluminumcasing.
3. 3 – Data Acquisition
3.1 – Format
The images that have been reduced and analyzed are using the Flexible Image Transport System
(FITS) image format, and the programs to reduce and analyze the data have been written in the
Interactive Data Language (IDL).
3.2 – Observing
Through several months of 2012, observations on a number of stars were taken using the fiber
scrambler through the CSHELL Spectrograph attached to IRTF on the top of Mauna Kea in
Hawaii. The images were labelled by their targets, central wavelength, slit width, exposure
time, inclusion of gas cell, and most importantly, type of fiber used.
3.3 – Stars Observed
Due to limits placed on the obtained data, the data sets have been narrowed down based on
the fiber type, target star, central wavelength, and exposure time. The data being reduced and
analyzed only includes images, data with an open slit, and, coincidentally, data excluding the
gas cell. As a result of this narrowing, only data from May and December 2012 has been
analyzed. Status of the fiber agitator was also included.
Dec-12
9-Dec
Image Numbers Fiber Target Wavelength Exposure Time Agitator
355-467 Rect 10m SVPeg 1.672 0.125 On
10-Dec
Image Numbers Fiber Target Wavelength Exposure Time Agitator
1801-2403 200um Oct 1m SVPeg 2.3-3
.125
1
Off
1585-1695 50um Oct 1m SVPeg 2.312 1 Off
11-Dec
Image Numbers Fiber Target Wavelength Exposure Time Agitator
2534-3403 200um Oct 1m SVPeg 2-2.4
.125
1
3304-3403 On
3404-3826 Rect 1m SVPeg 2-2.4 0.125 Off
3827-4386,4399-4408 Square 1m SVPeg 2-2.4 0.125 3877-3976 On
4. May-12
8-May
Image Numbers Fiber Target Wavelength
Exposure
Time
Agitator
6418-6573,6681-6693
6694-6753,6754-6807
6845-6963,6979-6988
7013-7051
200µm Oct 1m
102_her
Vega
2.1325 0.25
6845-6878 On
6982-6988 On
7227-7324,7449-7486 200µm Oct 10m Vega 3.3125 0.25 7449-7486 On
9-May
Image Numbers Fiber Target Wavelength
Exposure
Time
Agitator
8735-8754,8815-8894 200µm Oct 10m Arcturus 1.6 0.125 Off
8202-8529,8570-8589
8655-8694
200µm Oct 1m
Arcturus
45_Boo
1.6
2.3125
0.125
.25
Off
258-265 Rect 10m Vega 2.3125 0.5 Off
9495-9594,9759-9838 Square 10m Arcturus
1.6
2.3125
0.125 Off
9035-9114,9195-9394 Square 1m Arcturus
1.6
2.3126
1.125 Off
10-May
Image Numbers Fiber Target Wavelength
Exposure
Time
Agitator
5540-5859 200µm Oct 10m 55Alp_Oph 1.6 0.125 5540-5699 On
4410-4729 200µm Oct 1m 55Alp_Oph 1.6 0.125 4410-4569 On
4127-4316 50µm Oct 10m 55Alp_Oph 1.6 0.25 4127-4206 On
3620-3779,3844-4003 50µm Oct 1m 55Alp_Oph
1.6
2.3125
0.25
3700-3779 On
3844-3923 On
2004-2005,2068-2233
2496-2575,2767-2785
Rect 10m
Vega
36Eps_Boo
30Zet_Boo
49Del_Boo
109_Vir
16Alp_Boo
65Del_Her
55Alp_Oph
33_Cyg
5Alp_CrB
1.6
2.3125
2.6
.125
.25
.5
2
Off
3080-3239,3428-3587 Rect 1m 55Alp_Oph
1.6
2.3125
0.25
3160-3239 On
3428-3507 On
5184-5503 Square 10m 55Alp_Oph 1.6 0.125 Off
4823-5142 Square 1m 55Alp_Oph 1.6 0.125 4823-4882 On
5. 4 – Data Reduction
The first program is intended to reduce and process the images taken during the IRTF observing
sessions. Many individual dark images, long-exposure closed-shutter images taken of the dark
current running through the detector, must be stacked together into one image. Then, flat
images, shone at a bright light source to fully illuminate the detector to evenly distribute the
light, must be stacked together into one image. The dark image stack must be subtracted from
the image in order to correct for bad pixels and the resulting image must be divided by the flat
image stack in order to correct for uneven light distribution. In the second program, the line-
spread function of the final reduced images is plotted to check the variance and consistency of
pixel intensity across the different fiber types.
Figure 3: Image 5600 from May 10, 2012, showing the raw and reduced image ofthe 200 micron octagonal fiber, respectively.
6.
7. Fig. 4: Line Spread Functions oftheeight main fibers,full plotand zoomedin. From top to bottom: 200 micron Octagonal 10m fiber, images
5540-5859;200MicronOctagonal1mfiber, images 4410-4729; 50 micron Octagonal10m fiber,images 4127-4316; 50 micron octagonal 1m
fiber, images 3884-3923; Rectangular 10m fiber,images 2496-2575; Rectangular1m fiber, images 3080-3239; Square 10mfiber, images 5184-
5402; Square 1m fiber, images 4823-4881
4.1 – Fiber Agitator
In all of the images used, while science data was being obtained, the fiber agitator was
turned on or off at some point. This was accounted for in the plotting of the data, but in nearly
all cases, the status of the agitator did not seemto have an effect on the shape of the line
spread function. In the case of images 4410-4569 and 4570-4729, the shape was affected
slightly and the standard deviation rose from 1.6% to 2.1%. This was the most significant
change brought on by the fiber agitator.
8. Fig. 5: On the top, Images 4410-4569 of the200 micron Octagonal1mfiber, withagitator on.On the bottom, Images 4570-4729 ofthe same
set, with agitator off. There is a slight change in the shape ofthe LSF, but nearly no change in the standard deviation oft he plots. Upon
inspecting the data, this is the set that was changed the most from the changing status ofthe fiber agitator. Below the images are their
respective zoomed-in plots.
4.2 – Standard Deviation
Also recorded were tables showing the implot commands for each data set in relation to
their fiber shape along with the standard deviation of each set. Data sets that included a change
in agitator status were split into three sets: one set with the agitator off, one with the agitator
on, and both combined, in order to compare standard deviations and shapes of each set when
plotted.
December’s data was split up into many individual ten-image data sets excluding a few,
notably images 1585-1695 on December 10th, the only images taken with the 50 micron
octagonal fiber, having a standard deviation of 16.89%. Upon inspection, none of the remaining
data taken on December 10th, all taken using the 200 micron octagonal 1m fiber, had standard
deviations of less than 14% ranging up to 26%.
9. Fig. 6: Typicalplot ofdata using the200micron Octagonal1m fiberon thenight ofDecember 10th. This particular data set: images 2344-2353.
On the night of December 11th, the data for the 200 micron octagonal 1m fiber was
taken in sets of twenty images rather than ten. The data was much more consistent towards
the end of the fiber’s run, eventually narrowing down to 1.8% standard deviation after starting
the run at about 14%. The rectangular 1m fiber, back to sets of ten images, showed some
consistency over the night, reading in standard deviations of about 2.2% at its best, but despite
being relatively consistent with the line spread function, the light was shown to be brighter
through the edge of the fiber than the core in most cases.
Fig 7: More stableplot ofdata using theRectangular 1m fiber on the night ofDecember 11th. This particular data set: Images 3507-3516.
The Square 1m fiber, also using ten-image sets, had by far the most consistency of the
three fibers used on December 11th, with the standard deviation ranging between 2.4% and 4%
and rarely stepping outside of that range. Over the course of the run, however, while the light
on the right side of the fiber stayed consistently bright, the light on the left side of the fiber
started out dim, but was even with the right side in brightness by the end of the run.
10. Fig. 8: Data using the Square1m fiberon thenight ofDecember11th. On theleft: Images 4227-4236. On the right, images 4337-4346.
8-May
Fiber Command Standard Deviation
200µm Oct 1m
implot,6418,6573 0.0364
implot,6681,6693 0.0267
implot,6694,6753 0.0888
implot,6754,6807 0.0437
implot,6845,6878 0.0084
implot,6845,6963 0.0446
implot,6879,6963 0.0521
implot,6979,6988 0.0185
implot,7013,7051 0.0446
200µm Oct
10m
implot,7227,7324 0.0875
implot,7449,7486 0.0138
9-May
Fiber Command Standard Deviation
200µm Oct 10m
implot,8735,8754 0.007
implot,8815,8894 0.319
200µm Oct 1m
implot,8352,8529 0.078
implot,8570,8589 0.021
implot,8655,8694 0.008
Rect 10m implot,258,265 0.011
Square 10m
implot,9495,9594 0.004
implot,9759,9838 0.011
Square 1m
implot,9035,9114 0.129
implot,9195,9394 0.041
10-May
Fiber Command Standard Deviation
200µm Oct 10m implot,5540,5699 0.0099
11. implot,5540,5859 0.0104
implot,5700,5859 0.0106
200µm Oct 1m
implot,4410,4569 0.016
implot,4410,4729 0.0234
implot,4570,4729 0.021
50µm Oct 10m
implot,4127,4206 0.0209
implot,4127,4316 0.0202
implot,4207,4316 0.0198
50µm Oct 1m
implot,3620,3699 0.032
implot,3620,3779 0.021
implot,3700,3779 0.0253
implot,3884,3923 0.0262
implot,3884,4003 0.119
implot,3924,4003 0.144
Rect 10m
implot,2068,2171 0.348
implot,2181,2233 0.0793
implot,2496,2575 0.01
implot,2767,2785 0.028
Rect 1m
implot,3080,3159 0.021
implot,3080,3239 0.022
implot,3160,3239 0.023
implot,3428,3507 0.132
implot,3428,3587 0.137
implot,3508,3587 0.144
Square 10m
implot,5184,5402 0.0112
implot,5404,5503 0.0118
Square 1m
implot,4823,4881 0.018
implot,4883,5142 0.023
As shown by the chart, the lowest standard deviation in any of the given data sets is the
Square 10m fiber, at 0.4% on May 9th, 2012. However, the only other data set with a standard
deviation less than 1% seems to be both of the 200 micron Octagonal fibers, with at least one
set showing sub-1% standard deviation each night in May between the two of them.
5 – Errors and Odd Data
There were a few notable errors in the plots due to the state of the raw images
themselves that caused inconsistency when reduced. It is uncertain what caused the errors, but
they were present during the gathering of the data.
12. Fig. 7: Data takenusing the Square1m fiberon May10th. The top plot,images 4823-5142, showoneplot outofplace. The bottom plots, from
left to right, show images 4823-4881 and images 4883-5142. Image 4882 was determined to be the error image.
Fig. 8: On the left,image4881from May 10th. In the middle, the imagein question, image 4882.Betweenthetwo images thereis a noticeable
odd area at boththetop andbottom ofthe second image. On the right, the averaged result ofthe two images, which would normally be
uniform in the case oftwo consistent images. It is uncertain what may have caused this error.
17. Fig. 10: Program toplotthelinespreadfunction ofthereducedimages. Process includes summing inboth directions, normalization,and
calculation of standarddeviation.
7 – Conclusion
Code has been written for Missouri State University’s high-performance computing
cluster, Exo, to reduce images taken during several months’ time using Dr. Peter Plavchan’s
Non-Circular Core Fiber Scrambler at the CSHELL spectrograph on the top of Mauna Kea in
18. Hawaii. Code has also been written to plot the line spread function of pixel intensity with
respect to pixel position, with the purpose of determining the most reliable fiber core shape for
detecting exoplanets around M-Dwarf stars in the near-infrared using the radial velocity
method. After analyzing the data and determining the standard deviations of different sets of
data using different fiber shapes, it seems that all the fiber shapes have varying degrees of
reliability. However, by a small margin, it seems that the 200 micron Octagonal fibers, both the
1 and 10 meter variants, may be the most reliable fibers used in this analysis.
These plots and reduced images come from the two finished programs, unedited
throughout the process of reducing and plotting, and will require little to no upkeep as long as
the image sizes remain consistent using CSHELL. In the future the programs should be able to
quickly and efficiently reduce and analyze data taken using the CSHELL spectrograph or other
similar instruments that may replace it.
7 – References
1. Plavchan, P., et al., “Precision Near-Infrared Radial Velocity Instrumentation II: Non-Circular
Core Fiber Scrambler”, 2013, SPIE, in Optical Engineering + Applications, 8864 1J
2. Plavchan, P., et al., “Radial Velociy Prospects Current and Future,” 2015, ExoPAG Study
Analysis Group white paper
3. NASA Exoplanet Archive. 2015. Web.
<http://exoplanetarchive.ipac.caltech.edu/docs/counts_detail.html>