1. New thermal components were detected in both the northeastern shell and central region of SNR W28, confirming the presence of ejecta and a third thermal component in the central region potentially from a reflected shock.
2. Enhanced abundances of oxygen and magnesium were found in the northeastern shell, providing evidence of ejecta.
3. A powerlaw component, indicating non-thermal radiation, was detected for the first time in both the northeastern and southern regions of W28.
Flaring from the_supermassive_black_hole_in_mrk335_studied_with_swift_and_nustarSérgio Sacani
Os comportamentos estranhos e desconcertantes dos buracos negros tornam-se cada dia menos misteriosos, com as novas observações feitas com as missões Swift e NuSTAR da NASA. Os dois telescópios espaciais registraram um buraco negro supermassivo no meio de uma gigantesca explosão de luz de raio-X, ajudando os astrônomos a tentarem resolver um grande quebra-cabeça: Como os buracos negros supermassivos emitem flares?
Os resultados sugerem que os buracos negros supermassivos emitem flares de raios-X, quando suas coroas circundantes, fontes de partículas extremamente energéticas, são atiradas ou lançadas para fora dos buracos negros.
“Essa é a primeira vez que nós somos capazes de linkar o lançamento da coroa com uma flare”, disse Dan Wilkins, da Universidade de Saint Mary em Halifax, no Canadá e principal autor do artigo que descreve os resultados na revista Monthly Notices of The Royal Astronomical Society. “Isso nos ajudará a entender como os buracos negros supermassivos alimentam alguns dos objetos mais brilhantes do universo”.
Os buracos negros supermassivos não emitem luz por si só, mas eles as vezes são circundados por discos de material quente e brilhante. A gravidade do buraco negro puxa o gás ao redor, aquecendo esse material e fazendo com que ele brilhe com diferentes tipos de luz. Outra fonte da radiação perto do buraco negro é a coroa. As coroas são feitas de partículas altamente energéticas que geram luz de raio-X, mas os detalhes sobre sua aparência, ou como elas se formam, ainda não são claros.
The presentation file on workshop on Neutron and X-ray Characterisation on Caloric Materials, introduction to neutron scattering experiment with triple axis spectrometer for material scientist
Analysis of LENR and Recommendations for Cold Fusion Energy Using the BSM-SG ...Stoyan Sarg Sargoytchev
The fast growing branches of nanotechnology permitted advancements in different fields. Among them is the recent success in LENR. This requires a new theoretical understanding for processes in atomic sub-nanometric scale. The atomic models derived in the Basic Structures of Matter Supergravitation Unified Theory (BSM-SG), denoted as the BSM-SG models, fit quite well to this need. The BSM-SG theory reveals the existence of a space microcurvature surrounding the elementary particles and the superdense atomic nuclei. This explains why quantum mechanical models work only with energy levels and not with the dimension of length. The re-examination of scattering experiments from the BSM-SG point of view reveals a complex three-dimensional nuclear structure different from the quantum mechanical models of atoms based on the Bohr atomic model. Protons and neutrons are not point-like; the atomic nuclei have a much larger overall size, so the Coulomb barrier is not so strong. Therefore, some nuclear transmutations are possible at accessible temperatures. The pattern of the Periodic Table carries a strong signature of the spatial arrangement of protons and neutrons in the atomic nuclei. Nuclear stability depends on the symmetrical arrangement of protons and neutrons. Nuclear spin and nuclear magnetic resonance are also identifiable features of the nuclear configuration. The BSM-SG atomic models provide a new opportunity for analysis and prediction of many nuclear transmutations in the field of LENR. This issue is presented in the author’s book “Structural Physics of Nuclear Fusion”. The book describes a new method for theoretical estimation of the binding nuclear energy based on the derived nuclear dimensions of hadrons and derived strong force parameters. This provides new considerations for the proper selection of isotopes suitable for realization of cold fusion energy with minimal or no radioactive waste.
Space Radiation Superconductive Shield (SR2S) is an EU funded FP7 project which is researching new technology to protect astronauts in space from radiation. On 9th April 2014 in Torino, Italy, SR2S held their first conference to give an update on the project so far.
For more information visit:
www.sr2s.eu
Twitter - @SR2SMars
Flaring from the_supermassive_black_hole_in_mrk335_studied_with_swift_and_nustarSérgio Sacani
Os comportamentos estranhos e desconcertantes dos buracos negros tornam-se cada dia menos misteriosos, com as novas observações feitas com as missões Swift e NuSTAR da NASA. Os dois telescópios espaciais registraram um buraco negro supermassivo no meio de uma gigantesca explosão de luz de raio-X, ajudando os astrônomos a tentarem resolver um grande quebra-cabeça: Como os buracos negros supermassivos emitem flares?
Os resultados sugerem que os buracos negros supermassivos emitem flares de raios-X, quando suas coroas circundantes, fontes de partículas extremamente energéticas, são atiradas ou lançadas para fora dos buracos negros.
“Essa é a primeira vez que nós somos capazes de linkar o lançamento da coroa com uma flare”, disse Dan Wilkins, da Universidade de Saint Mary em Halifax, no Canadá e principal autor do artigo que descreve os resultados na revista Monthly Notices of The Royal Astronomical Society. “Isso nos ajudará a entender como os buracos negros supermassivos alimentam alguns dos objetos mais brilhantes do universo”.
Os buracos negros supermassivos não emitem luz por si só, mas eles as vezes são circundados por discos de material quente e brilhante. A gravidade do buraco negro puxa o gás ao redor, aquecendo esse material e fazendo com que ele brilhe com diferentes tipos de luz. Outra fonte da radiação perto do buraco negro é a coroa. As coroas são feitas de partículas altamente energéticas que geram luz de raio-X, mas os detalhes sobre sua aparência, ou como elas se formam, ainda não são claros.
The presentation file on workshop on Neutron and X-ray Characterisation on Caloric Materials, introduction to neutron scattering experiment with triple axis spectrometer for material scientist
Analysis of LENR and Recommendations for Cold Fusion Energy Using the BSM-SG ...Stoyan Sarg Sargoytchev
The fast growing branches of nanotechnology permitted advancements in different fields. Among them is the recent success in LENR. This requires a new theoretical understanding for processes in atomic sub-nanometric scale. The atomic models derived in the Basic Structures of Matter Supergravitation Unified Theory (BSM-SG), denoted as the BSM-SG models, fit quite well to this need. The BSM-SG theory reveals the existence of a space microcurvature surrounding the elementary particles and the superdense atomic nuclei. This explains why quantum mechanical models work only with energy levels and not with the dimension of length. The re-examination of scattering experiments from the BSM-SG point of view reveals a complex three-dimensional nuclear structure different from the quantum mechanical models of atoms based on the Bohr atomic model. Protons and neutrons are not point-like; the atomic nuclei have a much larger overall size, so the Coulomb barrier is not so strong. Therefore, some nuclear transmutations are possible at accessible temperatures. The pattern of the Periodic Table carries a strong signature of the spatial arrangement of protons and neutrons in the atomic nuclei. Nuclear stability depends on the symmetrical arrangement of protons and neutrons. Nuclear spin and nuclear magnetic resonance are also identifiable features of the nuclear configuration. The BSM-SG atomic models provide a new opportunity for analysis and prediction of many nuclear transmutations in the field of LENR. This issue is presented in the author’s book “Structural Physics of Nuclear Fusion”. The book describes a new method for theoretical estimation of the binding nuclear energy based on the derived nuclear dimensions of hadrons and derived strong force parameters. This provides new considerations for the proper selection of isotopes suitable for realization of cold fusion energy with minimal or no radioactive waste.
Space Radiation Superconductive Shield (SR2S) is an EU funded FP7 project which is researching new technology to protect astronauts in space from radiation. On 9th April 2014 in Torino, Italy, SR2S held their first conference to give an update on the project so far.
For more information visit:
www.sr2s.eu
Twitter - @SR2SMars
The new approach provides practical considerations for selection of the elements and their isotopes suitable for cold fusion energy and minimization of the radioactive waste.
The canarias einstein_ring_a_newly_discovered_optical_einstein_ringSérgio Sacani
We report the discovery of an optical Einstein Ring in the Sculptor constellation,
IAC J010127-334319, in the vicinity of the Sculptor Dwarf Spheroidal Galaxy. It is
an almost complete ring ( 300◦) with a diameter of 4.5 arcsec. The discovery was
made serendipitously from inspecting Dark Energy Camera (DECam) archive imaging
data. Confirmation of the object nature has been obtained by deriving spectroscopic
redshifts for both components, lens and source, from observations at the 10.4 m Gran
Telescopio CANARIAS (GTC) with the spectrograph OSIRIS. The lens, a massive
early-type galaxy, has a redshift of z = 0.581 while the source is a starburst galaxy
with redshift of z = 1.165. The total enclosed mass that produces the lensing effect
has been estimated to be Mtot = (1.86 ± 0.23) · 1012M⊙.
Solving the Multimessenger Puzzle of the AGN-starburst Composite Galaxy NGC 1068Sérgio Sacani
Multiwavelength observations indicate that some starburst galaxies show a dominant nonthermal contribution from
their central region. These active galactic nuclei (AGN)-starburst composites are of special interest, as both
phenomena on their own are potential sources of highly energetic cosmic rays and associated γ-ray and neutrino
emission. In this work, a homogeneous, steady-state two-zone multimessenger model of the nonthermal emission
from the AGN corona as well as the circumnuclear starburst region is developed and subsequently applied to the
case of NGC 1068, which has recently shown some first indications of high-energy neutrino emission. Here, we
show that the entire spectrum of multimessenger data—from radio to γ-rays including the neutrino constraint—can
be described very well if both, starburst and AGN corona, are taken into account. Using only a single emission
region is not sufficient.
An evolucionary missing_link_a_modest_mass_early_type_galaxy_hosting_an_over_...Sérgio Sacani
O buraco negro supermassivo de uma galáxia descoberta recentemente é bem maior do seria possível, de acordo com as atuais teorias da evolução galáctica. Novo trabalho, realizado por astrônomos na Universidade Keele e da Universidade Central Lancashire, mostra que o buraco negro é muito massivo do que deveria ser, se comparado com a massa da galáxia ao redor. Os cientistas publicaram os resultados em um artigo no Monthly Notices of The Royal Astronomical Society.
A galáxia, SAGE0536AGN, foi inicialmente descoberta com o Telescópio Espacial Spitzer da NASA na luz infravermelha. Apesar de ter no mínimo 9 bilhões de anos de vida, ela contém um núcleo galáctico ativo, um AGN, um objeto incrivelmente brilhante resultante da acreção de gás por um buraco negro supermassivo central. O gás é acelerado a altíssimas velocidades devido ao imenso campo gravitacional do buraco negro, fazendo com que o gás emita luz.
A equipe agora também confirmou a presença de um buraco negro medindo a velocidade do gás movendo-se ao seu redor. Usando o Southern African LArge Telescope, os cientistas observaram que uma linha de emissão de hidrogênio, no espectro da galáxia (onde a luz é dispersada em suas diferentes cores – um efeito similar é visto usando um prisma) é alargada pelo Efeito Doppler, onde o comprimento de onda (a cor) da luz de um objeto é desviada para o azul e para o vermelho dependendo se ele está se movendo para perto ou para longe nós. O grau de alargamento implica que o gás está se movendo ao redor numa alta velocidade, um resultado do forte campo gravitacional do buraco negro.
Maidana - Modification of particle accelerators for cargo inspection applicat...Carlos O. Maidana
As part of an accelerator based Cargo Inspection System, studies were made to develop a Cabinet Safe System by Optimization of the Beam Optics of Microwave Linear Accelerators of the IAC-Varian series working on the S-band and standing wave pi/2 mode. Measurements, modeling and simulations of the main subsystems were done and a Multiple Solenoidal System was designed.
This Cabinet Safe System based on a Multiple Solenoidal System minimizes the radiation field generated by the low efficiency of the microwave accelerators by optimizing the RF waveguide system and by also trapping secondaries generated in the accelerator head. These secondaries are generated mainly due to instabilities in the exit window region and particles backscattered from the target. The electron gun was also studied and software for its right mechanical design and for its optimization was developed as well. Besides the standard design method, an optimization of the injection process is accomplished by slightly modifying the gun configuration and by placing a solenoid on the waist position while avoiding threading the cathode with the magnetic flux generated.
The Multiple Solenoidal System and the electron gun optimization are the backbone of a Cabinet Safe System that could be applied not only to the 25 MeV IAC-Varian microwave accelerators but, by extension, to machines of different manufacturers as well. Thus, they constitute the main topic of this paper.
Todo mundo sabe que os raios produzidos pela Estrela da Morte em Guerra nas Estrelas não pode existir na vida real, porém no universo existem fenômenos que as vezes conseguem superar até a mais surpreendente ficção.
A galáxia Pictor A, é um desses objetos que possuem fenômenos tão espetaculares quanto aqueles exibidos no cinema. Essa galáxia localiza-se a cerca de 500 milhões de anos-luz da Terra e possui um buraco negro supermassivo no seu centro. Uma grande quantidade de energia gravitacional é lançada, à medida que o material cai em direção ao horizonte de eventos, o ponto sem volta ao redor do buraco negro. Essa energia produz um enorme jato de partículas que viajam a uma velocidade próxima da velocidade da luz no espaço intergaláctico, chamado de jato relativístico.
Para obter imagens desse jato, os cientistas usaram o Observatório de Raios-X Chandra, da NASA várias vezes durante 15 anos. Os dados do Chandra, apresentados em azul nas imagens, foram combinados com os dados obtidos em ondas de rádio a partir do Australia Telescope Compact Array, e são aparesentados em vermelho nas imagens.
I gave 1 hour seminar at ANSTO (Australian Nuclear Science and Technology Organization) to introduce my approach to magnetism. I see myself as an experimental physicist who is studying magnetism by using neutron scattering techniques. Throughout my career, I had learned local structure analysis (PDF), magnetic structural analysis, and inelastic neutron scattering technique to investigate superconductor, multiferroics, antiferromagnets, helimagnets, and frustrated magnets. I was trying to explain my approach to magnetism as an experiment physicist to both professional scientists and novices.
Analysis of the recent progress in LENR (cold fusion) by using of BSM-SG atomic models
(A talk presented at the 4-th International conference on nanotechnology Nanotek & Expo, 1-3 Dec 2014, San Francisco),
X-RAY MEASUREMENTS OF THE PARTICLE ACCELERATION PROPERTIES AT INWARD SHOCKS I...Sérgio Sacani
We present new evidence that the bright non-thermal X-ray emission features in the interior of the Cassiopeia A
supernova remnant (SNR) are caused by inward moving shocks based on Chandra and NuSTAR observations. Several
bright inward-moving filaments were identified using monitoring data taken by Chandra in 2000–2014. These inwardmoving shock locations are nearly coincident with hard X-ray (15–40 keV) hot spots seen by NuSTAR. From proper
motion measurements, the transverse velocities were estimated to be in the range ∼2,100–3,800 km s−1
for a distance of
3.4 kpc. The shock velocities in the frame of the expanding ejecta reach values of ∼5,100–8,700 km s−1
, slightly higher
than the typical speed of the forward shock. Additionally, we find flux variations (both increasing and decreasing) on
timescales of a few years in some of the inward-moving shock filaments. The rapid variability timescales are consistent
with an amplified magnetic field of B ∼ 0.5–1 mG. The high speed and low photon cut-off energy of the inward-moving
shocks are shown to imply a particle diffusion coefficient that departs from the Bohm regime (k0 = D0/D0,Bohm ∼ 3–8)
for the few simple physical configurations we consider in this study. The maximum electron energy at these shocks is
estimated to be ∼8–11 TeV, smaller than the values of ∼15–34 TeV inferred for the forward shock. Cassiopeia A is
dynamically too young for its reverse shock to appear to be moving inward in the observer frame. We propose instead
that the inward-moving shocks are a consequence of the forward shock encountering a density jump of & 5–8 in the
surrounding material.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
2. Target: SNR W28 (G6.4-0.1)
The Northeastern Shell (XMM-Newton data)
The Central Region (Chandra data)
Aims:
Detect powerlaw component (non-thermal X-
ray radiation) from W28’s NE shell for
broadband model
Study plasma properties of SNR W28
3. Ejected stellar material (ejecta) from a supernova, mixed with interstellar
medium (ISM) and compressed by forward shock, forms a SNR.
What is supernova remnant (SNR)?
4. SNR Evolution
Free Expansion
Adiabatic or
Sedov phase
Radiative phase
Mejecta >> Mswept-up
Ejecta expands without deceleration
Outer ISM shell by forward shock
Mejecta ~ Mswept-up
Significant deceleration
Ejecta merges into forward shock
Energy loss by adiabatic expansion
Efficient particle acceleration by
strong forward shock
Tejecta < 106K
Efficient cooling by radiation
Well-mixing between ejecta and ISM
No efficient particle acceleration due to slow forward shock
Disappearance when velocity drops to the typical value of ISM
ejecta
outer shell of
ISM by forward
shock
5. Types of SNR
Shell-type (e.g. Cassiopeia A)
• non-thermal X-ray emitting
shells
Crab-like (e.g. Crab Nebula)
• non-thermal X-ray or radio
radiation from a pulsar at
the centre
• faint shells or no shell at all
Composite-type
• if appear as both shell-like
and Crab-like
Mixed-morphology (e.g. W44)
• radio shell emission
• thermal X-ray center-filled
emission
• uniform temperature profile
not common in shell-type
SNRs
Ejecta Cassiopeia A
Crab Nebula
Radio
shell
Radio image
Thermal X-ray
center-filled
emission
X-ray image
W44
Neutron star
(a little spot)Non-thermal X-
ray emitting shell
by forward shock
Pulsar
6. SNR W28
• Mixed-morphology SNR
• 35000-15000 year old
• 50’x45’ angular size
• ~ 2kpc distant away
• Possibly evolved into its
radiative phase
Previous X-ray observation
with ROSAT and ASCA (2002):
Northeastern :
single thermal component
(0.6 keV ),
ISM abundance,
Center:
two thermal components
(1.8 keV and 0.6 keV)
Radio Image
of W28
ROSAT X-ray
Image of W28
7. Why Study SNR
W28?
• γ-ray emission near the
northeastern shell of W28
detected by H.E.S.S in 2008
and Fermi-LAT in 2010.
• γ-ray emission:
Inverse Compton
scattering (electrons)
Non-thermal
bremsstrahlung (electrons)
π0 decay (protons)
Detection of non-thermal X-ray
• helps determine if γ-ray emission
by electron or proton acceleration.
Radio Image
of W28
ROSAT X-ray
Image of W28
8. Download raw data from data
archive HEASARC and check
them, e.g. version, mode, etc.
Create a new event file
Check light curve
Filter the event file
Select region and extract the region’s
spectrum from the event file
Background subtraction
Spectral analysis and
fitting: XSPEC ver.12.5.1
Need reprocessing
for event file?
Flaring exist?
YES
YES
NO
NO
Basic Procedure of
Preparing Spectra
9. The CCD image of W28’s
NE shell from XMM (10
regions)
The CCD image of W28
from Chandra (8 regions)
Parameters concerned in
spectral fitting:
1. Temperature
2. Abundances of elementsROSAT X-ray
Image of W28
11. O
Mg
Si
S
The CCD image of W28’s NE
shell from XMM
pn-CCD
component
MOS-CCD
components
Northeastern Shell
12. Results for Northeastern Shell
All regions’ spectra are best
fitted by two thermal
components, different to single
thermal component observed by
ROSAT and ASCA.
Low temperature components
correspond to interstellar
medium (ISM) and high
temperature components
correspond to SNR ejecta.
Power-law model was also used
for fitting spectra, but photon
indices Γ > 4.0 for all the
regions, except REG G that Γ =
3.8.
13. Enhanced abundances of O
were detected in all regions,
and most of them show
enhanced abundances of Mg
as well, confirming the
presence of ejecta in W28’s NE
shell.
Emission from ejecta is still
strong enough to be resolved by
XMM, not expected from old
SNRs like W28.
Results for Northeastern Shell
14. Results from Chandra Data
Image of the Chandra
central chip with point
sources moved
15. Results from Chandra Data
Three-thermal model best fits the central
spectra. The component of ~1.8keV was also
observed by ROSAT and ASCA (2002), but two
thermal only.
The third thermal component may correspond
to reflected shock by (molecular) cloud.
Further analysis is needed to determine
whether the reflected shock model fitted the
data of the central region.
Image of the Chandra
central chip with point
sources moved
Three
thermal
components
Z
also observed by
ROSAT & ASCA
16. Results from Chandra DataChandra image with
point sources moved
Power-law component was
detected in R12.
Γ
17. Constraint on Non-thermal X-ray Radiation in
Northeastern Shell
The multi-band spectra of the Fermi-LAT source at the
NE boundary of SNR W28 (taken from Abdo et al. 2010).
Fermi
H.E.S.S
EGRET
18. We also attempt to estimate the mass of the
progenitor star associated with W28 by:
1. calculating the ejecta masses of
overabundant elements
2. comparing our values to the well-known
results (Thieleman et al. 1996).
The progenitor star’s mass:
8 M⊙ < M < 13 M⊙
There should be a neutron star
near the remnant’s center.
Mass of Progenitor Star
associated with W28
Our values are 10
times smaller than
that for 13M⊙
19. Identifying Background Point Sources and
Potential candidates for Neutron star
The CCD image of W28
from Chandra
• Five possible candidates
were identified (blue
circles).
• But determination of
their flux is needed to
find out the strong
candidates.
20. Summary
1. New thermal components detected in both the NE shell
and the central region of W28.
2. Confirmation of high temperature plasma of ~1.8 keV at
W28’s center.
3. First detection of ejecta with enhanced abundances of O
and Mg in W28’s NE shell .
4. First detection of powerlaw components in both W28’s
NE and S regions.
5. Determination of lower limit of flux of non-thermal X-ray
for the NE shell’s broadband modeling.
6. First identification of possible candidates of neutron star
associated with W28.
23. Results from Chandra Data
Oxygen line, not detected in other
Chandra’s regions we investigated, was
detected in both R1 and R2.
However I had trouble to determine the
best fits for R1 and R2 due to the
background spectrum dominant at
energies E > 3keV.
Considering consistency, the fits with solar
abundances are the preferred ones.
Chandra image with
point sources moved
Chandra image with
point sources moved
24. Ejecta
Injection of
ions to shock
Efficiency of
particle
acceleration
Amplification
of magnetic
field in shock
by CRs
Particle
acceleration or
re-acceleration
Collision
between
ejecta and
dense cloud
Reverse
shock
Modification
of shock by
CRs
?
Energy
spectrum
of CRs
SNR
Evolution
?
?
25. We use data from X-ray Multi-mirror Mission (XMM-Newton).
(above) XMM-Newton
satellite and (left) its X-ray
telescope’s basic structure.
26. CCDs of MOS1 (left) and MOS2 (right) cameras CCDs of pn camera
European Photon Imaging Camera (EPIC)(EPIC)
Welcome everyone. In the beginning My project as you see from the title is about studying supernova remnant in X-ray band. The remnant I investigated is called SNR W28. Basically, my project’s purpose is to attempt to detect non-thermal radiation associated with particle acceleration in W28, and study the plasma properties of W28.
Because I don’t expect everyone here familiar with supernova remnant, it is better to talk about what SNR actually is. As the name tells us, the SNR was produced by a supernova explosion occurring at the end of the life of a massive star. The mixture of ejected stellar material from the supernova and the surrounding interstellar medium, compressed by the forward shock, forms the supernova remnant.
According to the standard evolution, the supernova remnant will undergo three main phases when ejecta and forward shock are expanding outward to interstellar medium. The first phase is called free expansion phase, in which the ejecta is sweeping the surrounding gas and expanding without deceleration. Meanwhile we can see the shell of ISM formed at the boundary due to compression by the forward shock.
As long as the mass of interstellar medium swept by ejecta is comparable to the ejecta mass, then the SNR evolves into adiabatic phase, in which ejecta slows down significantly and merge into forwad shock, energy loss is due to adiabatic expansion only. This phase only last for thousands of years but it is believed that efficient particle acceleration can occur by the strong forward shock during the adiabatic phase.
Once the temperature becomes lower than a million Kelvin, and cooling by radiation is efficient, then the SNR enters the radiative phase. No efficient particle acceleration is expected because of slow forward shock.
When the velocity of the expanding ejecta drops to the typical value of ISM, then the ejecta totally merge with ISM, and the remnant disappears.
Astronomers used to classify SNRs into four types.
Shell-type is the common one which has non-thermal X-ray emitting shell near its boundary, as shown by the classical example Cas A.
Second type is called Crab-like in which we can see non-thermal X-ray or radio radiation from a fast spinning neutron star, called a pulsar, at the remnant's center.
If the remnants appear as shell-like and Crab-like at the same time, we usually called them composite-type.
The latest type is called mixed-morphology SNR. Mixed-morphology SNRs have radio emitting shell instead of non thermal X-ray shells like shell-type, and their central brightness is associated with thermal X-ray radiation emission coming from SNR material instead of non-thermal emission from pulsars. Also, uniform temperature profile is observed in mixed-morphology SNR.
My target, W28, belongs to the mixed-morphology SNR. It is one of oldest remnants in the Galaxy, and it is likely that W28 has evolved into its radiative phase.
The image at top right-hand corner is the radio image of W28. We can see the bright radio shell near the boundary. The red contour lines represent the X-ray emission observed by ROSAT in 2002.
From the previous X-ray observation with ROSAT and ASCA, there is single thermal component
My project was initially motivated by gamma-ray emission detected by H.E.S.S. near the northeastern region of W28.
Gamma-ray emission, as we know, can be produced through IC scattering or non-thermal bremsstrahlung both associated with electron acceleration, or neutral pion decay associated with proton acceleration.
In order to determine which kind of particle acceleration mainly contribute to the gamma-ray emission, we need detection of non-thermal X-ray emission from the northeastern shell for broadband modeling
The data we used was downloaded from the public data archive. All useful data is contained in event files. We need to inspect the event file and check if solar flare exists in the event files by looking at their light curves. If the event files are all right, we extract the spectra of regions form the event file and do the background subtraction to eliminate any contribution of background noise to the spectra. Then load the spectra into XSPEC, provided by NASA, for spectral analysis and spectral fitting.
For the northeastern shell, I investigated 10 regions. On the other hand, I studied 8 regions from Chandra data.
I used the models available in XSPEC to fit the spectrum of a region to derive its temperature and abundances of different elements.
For the northeastern shell, I was able to best fit all the regions using two thermal X-ray emission models. I am going to just show you the resultant spectra of several regions. You can see they are almost the same. The interesting thing is that we detect oxygen emission line which is unable to be detected by previous generation of X-ray telescopes before XMM and Chandra.
The table on the left side shows the best fit parameters of several regions. The spectra of all regions in the northeastern shell are best fitted by two thermal components, different to the previous observation with ROSAT and ASCA, in which they observed single thermal component only.
Although we could not detect powerlaw component in any region from XMM data for braodband modeling, we could still estimate the constraint on the non-thermal X-ray radiation. To do so, I intentionally add a powerlaw component with a photon index fixed to be the value of 2.2, then fine-tune the normalization of the powerlaw component unit 3 sigma confidence was achieved. Then the resultant photon flux we determined in this way would be the upper limit of photon flux of the non-thermal X-ray at the NE shell. The upper limit we found is about 0.2eVcm-2s-1 at around 1keV.
The XMM observatory contains three EPIC detectors: two MOS cameras and a pn camera. All three cameras can detect photons with energy between 0.15 and 15 keV. Each EPIC detector has the field of view (FOV) of 30 arcmin and energy resolution of 0.15keV at
1keV.
ACIS is composed of 10 planar, 1024 times 1024 pixel CCDs. Each CCD provides 8.4’times8.4’ observational view on the sky. Six of them forms a linear array and the rest is arranged as a square array. Up to 6 ACIS CCDs in any possible combination can
be operated simultaneously. In our case, I0,I2 and S2-S5 CCDs were used during the observation.