Observed glacier and volatile distribution on Pluto from atmosphere–topograph...Sérgio Sacani
Pluto has a variety of surface frosts and landforms as well as a
complex atmosphere1. There is ongoing geological activity related
to the massive Sputnik Planum glacier, mostly made of nitrogen (N2)
ice mixed with solid carbon monoxide and methane2, covering the
4-kilometre-deep, 1,000-kilometre-wide basin of Sputnik Planum1,3
near the anti-Charon point. The glacier has been suggested to arise
from a source region connected to the deep interior, or from a sink
collecting the volatiles released planetwide1. Thin deposits of N2
frost, however, were also detected at mid-northern latitudes and
methane ice was observed to cover most of Pluto except for the
darker, frost-free equatorial regions2. Here we report numerical
simulations of the evolution of N2, methane and carbon monoxide
on Pluto over thousands of years. The model predicts N2 ice
accumulation in the deepest low-latitude basin and the threefold
increase in atmospheric pressure that has been observed to occur
since 19884–6. This points to atmospheric–topographic processes as
the origin of Sputnik Planum’s N2 glacier. The same simulations also
reproduce the observed quantities of volatiles in the atmosphere and
show frosts of methane, and sometimes N2, that seasonally cover the
mid- and high latitudes, explaining the bright northern polar cap
reported in the 1990s7,8 and the observed ice distribution in 20152.
The model also predicts that most of these seasonal frosts should
disappear in the next decade.
A highly magnetized twin-jet base pinpoints a supermassive black holeSérgio Sacani
Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical
models based on (Blandford & Znajek 1977, MNRAS, 179, 433) extract the rotational energy from a Kerr black hole, which could
be the case for NGC1052, to launch these jets. This requires magnetic fields on the order of 103 G to 104 G. We imaged the vicinity
of the SMBH of the AGN NGC1052 with the Global Millimetre VLBI Array and found a bright and compact central feature that is
smaller than 1.9 light days (100 Schwarzschild radii) in radius. Interpreting this as a blend of the unresolved jet bases, we derive the
magnetic field at 1 Schwarzschild radius to lie between 200 G and 8:3 104 G consistent with Blandford & Znajek models.
PROBING FOR EVIDENCE OF PLUMES ON EUROPA WITH HST/STISSérgio Sacani
Roth et al. (2014a) reported evidence for plumes of water venting from a southern high latitude
region on Europa – spectroscopic detection of off-limb line emission from the dissociation
products of water. Here, we present Hubble Space Telescope (HST) direct images of Europa in
the far ultraviolet (FUV) as it transited the smooth face of Jupiter, in order to measure absorption
from gas or aerosols beyond the Europa limb. Out of ten observations we found three in which
plume activity could be implicated. Two show statistically significant features at latitudes similar
to Roth et al., and the third, at a more equatorial location. We consider potential systematic
effects that might influence the statistical analysis and create artifacts, and are unable to find any
that can definitively explain the features, although there are reasons to be cautious. If the
apparent absorption features are real, the magnitude of implied outgassing is similar to that of the
Roth et al. feature, however the apparent activity appears more frequently in our data.
Galaxy dynamics and the mass density of the universeSérgio Sacani
Dynamical evidence accumulated over the
past 20 years has convinced astronomers that luminous matter
in a spiral galaxy constitutes no more than 10% of the mass of
a galaxy. An additional 90% is inferred by its gravitational
effect on luminous material. Here I review recent observations
concerning the distribution of luminous and nonluminous
matter in the Milky Way, in galaxies, and in galaxy clusters.
Observations of neutral hydrogen disks, some extending in
radius several times the optical disk, confirm that a massive
dark halo is a major component of virtually every spiral. A
recent surprise has been the discovery that stellar and gas
motions in ellipticals are enormously complex. To date, only for
a few spheroidal galaxies do the velocities extend far enough to
probe the outer mass distribution. But the diverse kinematics
of inner cores, peripheral to deducing the overall mass distribution,
offer additional evidence that ellipticals have acquired
gas-rich systems after initial formation. Dynamical results are
consistent with a low-density universe, in which the required
dark matter could be baryonic. On smallest scales of galaxies
[10 kiloparsec (kpc); H. = 50 kmsec'lmegaparsec'11 the
luminous matter constitutes only 1% of the closure density. On
scales greater than binary galaxies (i.e., .100 kpc) all systems
indicate a density -10% of the closure density, a density
consistent with the low baryon density in the universe. If
large-scale motions in the universe require a higher mass
density, these motions would constitute the first dynamical
evidence for nonbaryonic matter in a universe of higher
density.
Observed glacier and volatile distribution on Pluto from atmosphere–topograph...Sérgio Sacani
Pluto has a variety of surface frosts and landforms as well as a
complex atmosphere1. There is ongoing geological activity related
to the massive Sputnik Planum glacier, mostly made of nitrogen (N2)
ice mixed with solid carbon monoxide and methane2, covering the
4-kilometre-deep, 1,000-kilometre-wide basin of Sputnik Planum1,3
near the anti-Charon point. The glacier has been suggested to arise
from a source region connected to the deep interior, or from a sink
collecting the volatiles released planetwide1. Thin deposits of N2
frost, however, were also detected at mid-northern latitudes and
methane ice was observed to cover most of Pluto except for the
darker, frost-free equatorial regions2. Here we report numerical
simulations of the evolution of N2, methane and carbon monoxide
on Pluto over thousands of years. The model predicts N2 ice
accumulation in the deepest low-latitude basin and the threefold
increase in atmospheric pressure that has been observed to occur
since 19884–6. This points to atmospheric–topographic processes as
the origin of Sputnik Planum’s N2 glacier. The same simulations also
reproduce the observed quantities of volatiles in the atmosphere and
show frosts of methane, and sometimes N2, that seasonally cover the
mid- and high latitudes, explaining the bright northern polar cap
reported in the 1990s7,8 and the observed ice distribution in 20152.
The model also predicts that most of these seasonal frosts should
disappear in the next decade.
A highly magnetized twin-jet base pinpoints a supermassive black holeSérgio Sacani
Supermassive black holes (SMBH) are essential for the production of jets in radio-loud active galactic nuclei (AGN). Theoretical
models based on (Blandford & Znajek 1977, MNRAS, 179, 433) extract the rotational energy from a Kerr black hole, which could
be the case for NGC1052, to launch these jets. This requires magnetic fields on the order of 103 G to 104 G. We imaged the vicinity
of the SMBH of the AGN NGC1052 with the Global Millimetre VLBI Array and found a bright and compact central feature that is
smaller than 1.9 light days (100 Schwarzschild radii) in radius. Interpreting this as a blend of the unresolved jet bases, we derive the
magnetic field at 1 Schwarzschild radius to lie between 200 G and 8:3 104 G consistent with Blandford & Znajek models.
PROBING FOR EVIDENCE OF PLUMES ON EUROPA WITH HST/STISSérgio Sacani
Roth et al. (2014a) reported evidence for plumes of water venting from a southern high latitude
region on Europa – spectroscopic detection of off-limb line emission from the dissociation
products of water. Here, we present Hubble Space Telescope (HST) direct images of Europa in
the far ultraviolet (FUV) as it transited the smooth face of Jupiter, in order to measure absorption
from gas or aerosols beyond the Europa limb. Out of ten observations we found three in which
plume activity could be implicated. Two show statistically significant features at latitudes similar
to Roth et al., and the third, at a more equatorial location. We consider potential systematic
effects that might influence the statistical analysis and create artifacts, and are unable to find any
that can definitively explain the features, although there are reasons to be cautious. If the
apparent absorption features are real, the magnitude of implied outgassing is similar to that of the
Roth et al. feature, however the apparent activity appears more frequently in our data.
Galaxy dynamics and the mass density of the universeSérgio Sacani
Dynamical evidence accumulated over the
past 20 years has convinced astronomers that luminous matter
in a spiral galaxy constitutes no more than 10% of the mass of
a galaxy. An additional 90% is inferred by its gravitational
effect on luminous material. Here I review recent observations
concerning the distribution of luminous and nonluminous
matter in the Milky Way, in galaxies, and in galaxy clusters.
Observations of neutral hydrogen disks, some extending in
radius several times the optical disk, confirm that a massive
dark halo is a major component of virtually every spiral. A
recent surprise has been the discovery that stellar and gas
motions in ellipticals are enormously complex. To date, only for
a few spheroidal galaxies do the velocities extend far enough to
probe the outer mass distribution. But the diverse kinematics
of inner cores, peripheral to deducing the overall mass distribution,
offer additional evidence that ellipticals have acquired
gas-rich systems after initial formation. Dynamical results are
consistent with a low-density universe, in which the required
dark matter could be baryonic. On smallest scales of galaxies
[10 kiloparsec (kpc); H. = 50 kmsec'lmegaparsec'11 the
luminous matter constitutes only 1% of the closure density. On
scales greater than binary galaxies (i.e., .100 kpc) all systems
indicate a density -10% of the closure density, a density
consistent with the low baryon density in the universe. If
large-scale motions in the universe require a higher mass
density, these motions would constitute the first dynamical
evidence for nonbaryonic matter in a universe of higher
density.
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...Sérgio Sacani
Aims. We present the first public release of photometric redshifts, galaxy rest frame properties and associated magnification values
in the cluster and parallel pointings of the first two Frontier Fields, Abell-2744 and MACS-J0416. The released catalogues aim to
provide a reference for future investigations of extragalactic populations in these legacy fields: from lensed high-redshift galaxies to
cluster members themselves.
Methods.We exploit a multiwavelength catalogue, ranging from Hubble Space Telescope (HST) to ground-based K and Spitzer IRAC,
which is specifically designed to enable detection and measurement of accurate fluxes in crowded cluster regions. The multiband
information is used to derive photometric redshifts and physical properties of sources detected either in the H-band image alone, or
from a stack of four WFC3 bands. To minimize systematics, median photometric redshifts are assembled from six di erent approaches
to photo-z estimates. Their reliability is assessed through a comparison with available spectroscopic samples. State-of-the-art lensing
models are used to derive magnification values on an object-by-object basis by taking into account sources positions and redshifts.
Results. We show that photometric redshifts reach a remarkable 3–5% accuracy. After accounting for magnification, the H-band
number counts are found to be in agreement at bright magnitudes with number counts from the CANDELS fields, while extending
the presently available samples to galaxies that, intrinsically, are as faint as H 32 33, thanks to strong gravitational lensing. The
Frontier Fields allow the galaxy stellar mass distribution to be probed, depending on magnification, at 0.5–1.5 dex lower masses with
respect to extragalactic wide fields, including sources at Mstar 107–108 M at z > 5. Similarly, they allow the detection of objects
with intrinsic star formation rates (SFRs) >1 dex lower than in the CANDELS fields reaching 0.1–1 M =yr at z 6–10.
Convective storms in Europe: a look back at COPS and CSIPAndrew Russell
A seminar given at RMS in London on 16th March on the main results from the Convective Storm Initiation Project (CSIP) and the Convective and Orographically-induced Precipitation Study (COPS).
On the (Non-)Enhancment of the Lyα Equivalent Width by a Multiphase Interstel...Edmund Christian Herenz
Talk at MUSE Science Meeting @ Leibniz-Institut für Astrophysik in Potsdam (AIP) presenting a recent Paper by P. Laursen et al. http://dx.doi.org/10.1088/0004-637X/766/2/124
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.
Superflares in G, K and M Type Dwarfs from Kepler ObservationsSimon Candelaresi
We study the occurrence of superflares in G, K and M type dwarfs from lightcurves obtained by the Kepler mission. From that set 380 stars are detected with flares above 10^34 erg with 1690 such events. Various stellar parameters are considered here to find what circumstances are favorable for the occurrence of superflares. With decreasing effective temperature the flaring rate increases, as well as with an increase in the star's rotation rate. Star spots, which are a proxy for the magnetic field strength and dynamo activity, are seen more frequently in flaring stars and cover a larger proportion of the star's. surface. Using Ohmic dissipation as proxy for flare events, we perform simulations for a turbulent dynamo and find an increase of Ohmic dissipation as the dynamo number increases, in line with the observations.
The Solar System by VI - Edison (PASAY CITY WEST HIGH SCHOOL, 2012)Fatimah Sol Jalmaani
We did last year (2012), with my classmates Gloriele and Abegail for a report. Anyone can get information from it, but if you plan to use ALL OF IT, make sure to site the source, okay????! That's all! :D
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...Sérgio Sacani
Aims. We present the first public release of photometric redshifts, galaxy rest frame properties and associated magnification values
in the cluster and parallel pointings of the first two Frontier Fields, Abell-2744 and MACS-J0416. The released catalogues aim to
provide a reference for future investigations of extragalactic populations in these legacy fields: from lensed high-redshift galaxies to
cluster members themselves.
Methods.We exploit a multiwavelength catalogue, ranging from Hubble Space Telescope (HST) to ground-based K and Spitzer IRAC,
which is specifically designed to enable detection and measurement of accurate fluxes in crowded cluster regions. The multiband
information is used to derive photometric redshifts and physical properties of sources detected either in the H-band image alone, or
from a stack of four WFC3 bands. To minimize systematics, median photometric redshifts are assembled from six di erent approaches
to photo-z estimates. Their reliability is assessed through a comparison with available spectroscopic samples. State-of-the-art lensing
models are used to derive magnification values on an object-by-object basis by taking into account sources positions and redshifts.
Results. We show that photometric redshifts reach a remarkable 3–5% accuracy. After accounting for magnification, the H-band
number counts are found to be in agreement at bright magnitudes with number counts from the CANDELS fields, while extending
the presently available samples to galaxies that, intrinsically, are as faint as H 32 33, thanks to strong gravitational lensing. The
Frontier Fields allow the galaxy stellar mass distribution to be probed, depending on magnification, at 0.5–1.5 dex lower masses with
respect to extragalactic wide fields, including sources at Mstar 107–108 M at z > 5. Similarly, they allow the detection of objects
with intrinsic star formation rates (SFRs) >1 dex lower than in the CANDELS fields reaching 0.1–1 M =yr at z 6–10.
Convective storms in Europe: a look back at COPS and CSIPAndrew Russell
A seminar given at RMS in London on 16th March on the main results from the Convective Storm Initiation Project (CSIP) and the Convective and Orographically-induced Precipitation Study (COPS).
On the (Non-)Enhancment of the Lyα Equivalent Width by a Multiphase Interstel...Edmund Christian Herenz
Talk at MUSE Science Meeting @ Leibniz-Institut für Astrophysik in Potsdam (AIP) presenting a recent Paper by P. Laursen et al. http://dx.doi.org/10.1088/0004-637X/766/2/124
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.
Superflares in G, K and M Type Dwarfs from Kepler ObservationsSimon Candelaresi
We study the occurrence of superflares in G, K and M type dwarfs from lightcurves obtained by the Kepler mission. From that set 380 stars are detected with flares above 10^34 erg with 1690 such events. Various stellar parameters are considered here to find what circumstances are favorable for the occurrence of superflares. With decreasing effective temperature the flaring rate increases, as well as with an increase in the star's rotation rate. Star spots, which are a proxy for the magnetic field strength and dynamo activity, are seen more frequently in flaring stars and cover a larger proportion of the star's. surface. Using Ohmic dissipation as proxy for flare events, we perform simulations for a turbulent dynamo and find an increase of Ohmic dissipation as the dynamo number increases, in line with the observations.
The Solar System by VI - Edison (PASAY CITY WEST HIGH SCHOOL, 2012)Fatimah Sol Jalmaani
We did last year (2012), with my classmates Gloriele and Abegail for a report. Anyone can get information from it, but if you plan to use ALL OF IT, make sure to site the source, okay????! That's all! :D
Earth science or Geoscience is an all-embracing term referring to the fields of science dealing with planet Earth. It is arguably a special branch of planetary science, though with a much older history. There are both reductionist and holistic approaches to Earth sciences. The formal discipline of Earth sciences may include the study of the atmosphere, hydrosphere, oceans and biosphere, as well as the solid earth. Typically, Earth scientists will use tools from physics, chemistry, biology, chronology, and mathematics to build a quantitative understanding of how the Earth system works, and how it evolved to its current state.
"Planet Formation in Dense Star Clusters" presented by Dr. Henry Throop (Uni...Rene Kotze
NITheP WITS node seminar
"Planet Formation in Dense Star Clusters"
to be presented by Dr. Henry Throop (University of Pretoria)
http://www.nithep.ac.za/4hu.htm
The extremely high albedo of LTT 9779 b revealed by CHEOPSSérgio Sacani
Optical secondary eclipse measurements of small planets can provide a wealth of information about the reflective properties
of these worlds, but the measurements are particularly challenging to attain because of their relatively shallow depth. If such signals
can be detected and modeled, however, they can provide planetary albedos, thermal characteristics, and information on absorbers in
the upper atmosphere.
Aims. We aim to detect and characterize the optical secondary eclipse of the planet LTT 9779 b using the CHaracterising ExOPlanet
Satellite (CHEOPS) to measure the planetary albedo and search for the signature of atmospheric condensates.
Methods. We observed ten secondary eclipses of the planet with CHEOPS. We carefully analyzed and detrended the light curves using
three independent methods to perform the final astrophysical detrending and eclipse model fitting of the individual and combined light
curves.
Results. Each of our analysis methods yielded statistically similar results, providing a robust detection of the eclipse of LTT 9779 b
with a depth of 115±24 ppm. This surprisingly large depth provides a geometric albedo for the planet of 0.80+0.10
−0.17, consistent with
estimates of radiative-convective models. This value is similar to that of Venus in our own Solar System. When combining the eclipse
from CHEOPS with the measurements from TESS and Spitzer, our global climate models indicate that LTT 9779 b likely has a super
metal-rich atmosphere, with a lower limit of 400× solar being found, and the presence of silicate clouds. The observations also reveal
hints of optical eclipse depth variability, but these have yet to be confirmed.
Conclusions. The results found here in the optical when combined with those in the near-infrared provide the first steps toward
understanding the atmospheric structure and physical processes of ultrahot Neptune worlds that inhabit the Neptune desert.
The shadow _of_the_flying_saucer_a_very_low_temperature_for_large_dust_grainsSérgio Sacani
Os astrónomos usaram o ALMA e os telescópios do IRAM para fazer a primeira medição direta da temperatura dos grãos de poeira grandes situados nas regiões periféricas de um disco de formação planetária que se encontra em torno de uma estrela jovem. Ao observar de forma inovadora um objeto cujo nome informal é Disco Voador, os astrónomos descobriram que os grãos de poeira são muito mais frios do que o esperado: -266º Celsius. Este resultado surpreendente sugere que os modelos teóricos destes discos precisam de ser revistos.
Uma equipa internacional liderada por Stephane Guilloteau do Laboratoire d´Astrophysique de Bordeaux, França, mediu a temperatura de enormes grãos de poeira que se encontram em torno da jovem estrela 2MASS J16281370-2431391 na região de formação estelar Rho Ophiuchi, a cerca de 400 anos-luz de distância da Terra.
Esta estrela encontra-se rodeada por um disco de gás e poeira — chamado disco protoplanetário, uma vez que se encontra na fase inicial da formação de um sistema planetário. Este disco é visto de perfil quando observado a partir da Terra e a sua aparência em imagens no visível levou a que se lhe desse o nome informal de Disco Voador.
Os astrónomos utilizaram o ALMA para observar o brilho emitido pelas moléculas de monóxido de carbono no disco da 2MASS J16281370-2431391. As imagens revelaram-se extremamente nítidas e descobriu-se algo estranho — em alguns casos o sinal recebido era negativo. Normalmente um sinal negativo é fisicamente impossível, mas neste caso existe uma explicação, que leva a uma conclusão surpreendente.
3d modeling of_gj1214b_atmosphere_formation_of_inhomogeneous_high_cloouds_and...Sérgio Sacani
Uma equipe de cientistas da Universidade de Washington e da Universidade de Toronto foram os primeiros a simular nuvens exóticas em 3D na atmosfera de um exoplaneta.
O objeto em questão, é o GJ 1214b, um exoplaneta chamado de mini-Netuno que foi descoberto, seis anos atrás pelos astrônomos no Harvard-Smithsonian Center for Astrophysics.
Também conhecido como Gliese 1214b, esse mundo tem cerca de 2.7 vezes o diâmetro da Terra e uma massa quase 7 vezes maior que a massa do nosso planeta. Ele está localizado a cerca de 52 anos-luz de distância na constelação de Ophiuchus.
O planeta orbita a estrela anã vermelha, GJ 1214, a cada 38 horas, a uma distância de 1.3 milhões de milhas.
De acordo com estudos prévios, o planeta tem uma atmosfera rica em água ou hidrogênio com extensas nuvens.
“Deve existir altas nuvens ou uma névoa orgânica na atmosfera – como nós observamos em Titã. Sua temperatura atmosférica excede o ponto de fusão da água”, disse o Dr. Benjamin Charnay, um dos membros da equipe da Universidade de Washington.
Invited Seminar presented at the VIA Forum Astroparticle Physics Forum COSMOVIA
21 March 2020
http://viavca.in2p3.fr/2010c_o_s_m_o_v_i_a__forum_sd24fsdf4zerfzef4ze5f4dsq34sdteerui45788789745rt7yr68t4y54865h45g4hfg56h45df4h86d48h48t7uertujirjtiorjhuiofgrdsqgxcvfghfg5h40yhuyir/viewtopic.php?f=73&t=3705&sid=c56cbf76f87536fc4c3ff216d9edaba2
Author: O.M. Lecian
Speaker: O.M. Lecian
Abstract: The LHAASO experiment is aimed at detecting highly-energetic particles of cosmological origin within a large
range of energies.
The sensitivity of the experimental apparatus can within the frameworks of statistical fluctuations of the
background.
Acceleration and lower-energy particles can be analyzed.
The anisotropy mass composition of cosmic rays can analytically described.
The LHAASO Experiment is also suited for detecting particles of cosmological origin originated from the breach
(and/or other kinds of modifications) of particle theories paradigms comprehending other symmetry groups.
Some physical implications of anisotropies can be looked for.
The study of anisotropy distribution for particles of cosmological origin as well as the anisotropies of their velocities
both in the case of a flat Minkowskian background as well as in the case of curved space-time can be investigated,
as far as the theoretical description of the cross-section is concerned, as well as for the theoretical expressions of
such quantities to be analyzed.
The case of a geometrical phase of particles can be schematized by means of a geometrical factor.
Particular solutions are found under suitable approximations.
A comparison with the study of ellipsoidal galaxies is achieved.
The case of particles with anisotropies in velocities falling off faster than dark matter (DM) is compared.
The study of possible anisotropies in the spatial distribution of cosmological particles can therefore be described
also deriving form the interaction of cosmic particles with the gravitational field, arising at quantum distances, at
the semiclassical level and at the classical scales, within the framework of the proper description of particles
anisotropies properties.
An unusual white dwarf star may be a surviving remnant of a subluminous Type ...Sérgio Sacani
Subluminous Type Ia supernovae, such as the Type Iax–class prototype SN 2002cx, are
described by a variety of models such as the failed detonation and partial deflagration
of an accreting carbon-oxygen white dwarf star or the explosion of an accreting, hybrid
carbon-oxygen-neon core. These models predict that bound remnants survive such
events with, according to some simulations, a high kick velocity.We report the discovery
of a high proper motion, low-mass white dwarf (LP 40-365) that travels at a velocity
greater than the Galactic escape velocity and whose peculiar atmosphere is dominated
by intermediate-mass elements. Strong evidence indicates that this partially burnt
remnant was ejected following a subluminous Type Ia supernova event. This supports the
viability of single-degenerate supernova progenitors.
Water vapor mapping on mars using omega mars expressAwad Albalwi
A systematic mapping of water vapor on Mars has been achieved using the imaging spectrometer OMEGA aboard the Mars Express
spacecraft, using the depth of the 2.6 mm (n1, n3) band of H2O. We report results obtained during two periods: (1) Ls ¼ 330–401
(January–June 2004), before and after the equinox, and (2) Ls ¼ 90–1251, which correspond to early northern summer
Probing the innermost_regions_of_agn_jets_and_their_magnetic_fields_with_radi...Sérgio Sacani
Desde 1974, observações feitas com o chamado Long Baseline Interferometry, ou VLBI, combinaram sinais de um objeto cósmico recebidos em diferentes rádio telescópios espalhados pelo globo para criar uma antena com o tamanho equivalente à maior separação entre elas. Isso fez com que fosse possível fazer imagens com uma nitidez sem precedentes, com uma resolução 1000 vezes melhor do que Hubble consegue na luz visível. Agora, uma equipe internacional de astrônomos quebrou todos os recordes combinando 15 rádio telescópios na Terra e a antena de rádio da missão RadioAstron, da agência espacial russa, na órbita da Terra. O trabalho, liderado pelo Instituto de Astrofísica de Andalucía, o IAA-CSIC, forneceu novas ideias sobre a natureza das galáxias ativas, onde um buraco negro extremamente massivo engole a matéria ao redor enquanto simultaneamente emite um par de jatos de partículas de alta energia e campos magnéticos a velocidades próximas da velocidade da luz.
Observações feitas no comprimento de onda das micro-ondas são essenciais para explorar esses jatos, já que os elétrons de alta energia se movendo em campos magnéticos são mais proficientes em produzir micro-ondas. Mas a maioria das galáxias ativas com jatos brilhantes estão a bilhões de anos-luz de distância da Terra, de modo que esses jatos são minúsculos no céu. Desse modo a alta resolução é essencial para observar esses jatos em ação e então revelar fenômenos como as ondas de choque e a turbulência que controla o quanto de luz é produzida num dado tempo. “Combinando pela primeira vez rádio telescópios na Terra com rádio telescópios no espaço, operando na máxima resolução, tem permitido que a nossa equipe crie uma antena que tem um tamanho equivalente a 8 vezes o diâmetro da Terra, correspondendo a 20 micro arcos de segundo”, disse José L; Gómez, o líder da equipe no Instituto de Astrofísica de Andalucía, IAA-CSIC.
Evidence of a plume on Europa from Galileo magnetic and plasma wave signaturesSérgio Sacani
The icy surface of Jupiter’s moon, Europa, is thought to lie
on top of a global ocean1–4. Signatures in some Hubble Space
Telescope images have been associated with putative water
plumes rising above Europa’s surface5,6, providing support for
the ocean theory. However, all telescopic detections reported
were made at the limit of sensitivity of the data5–7
, thereby calling
for a search for plume signatures in in-situ measurements.
Here, we report in-situ evidence of a plume on Europa from
the magnetic field and plasma wave observations acquired on
Galileo’s closest encounter with the moon. During this flyby,
which dropped below 400 km altitude, the magnetometer8
recorded an approximately 1,000-kilometre-scale field rotation
and a decrease of over 200 nT in field magnitude, and
the Plasma Wave Spectrometer9 registered intense localized
wave emissions indicative of a brief but substantial increase
in plasma density. We show that the location, duration and
variations of the magnetic field and plasma wave measurements
are consistent with the interaction of Jupiter’s corotating
plasma with Europa if a plume with characteristics inferred
from Hubble images were erupting from the region of Europa’s
thermal anomalies. These results provide strong independent
evidence of the presence of plumes at Europa.
1. Modeling extrasolar planetary atmospheres Planetary Systems as Potential Sites for Life Special Session SpS6 - Aug. 11th, 11h-11h20 France Allard Directrice de Recherche, CNRS Centre de Recherche Astrophysique de Lyon
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6. HD209458b H 2 O detection! Barman (ApJ 661, L191, 2007)
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8. Quasi-2D, single layered fluid dynamics [Left] Equatorial and polar views of potential vorticity (a flow tracer) in a specific hot Jupiter model from Cho et al. (2003, 2007). Note the prominent circumpolar vortices formed as a result of potential vorticity conservation. [Right] Corresponding zonally averaged wind profile, characterized by a small number of broad jets (three in this case). Fig 3 of Showman, Menou & Cho (2007) Cho et al. (2003, 2007)
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13. HD189733b Simulations vs transit observations. The overall transmission spectrum is shaped by the water absorption in the infrared (Tinetti et al., 2007b) but methane is needed to explain the NIR (Swain, Vasisht, Tinetti, 2008). At shorter wavelength, the increasing flatness of the spectrum could be explained by hazes. Broad band photometry is not enough to distinguish the different additional molecules. Figs. 1 & 2 of Tinetti & Baulieu (2008)
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15. EGPs: the CoRoT-3b case Temperature inversion in outer layers Temperature raises above condensation temperature Dust only forms in the optically thin upper layers CoRot-3b = black curve CoRot-3b = red curves No stellar irradiation Half-sphere redistribution
16. Main actors of exoplanet’s field Plan-parallel, two-stream, WITH scattering CE not updated with time Gas + dust 1D, time relaxation, Ad-hoc rotation, Global 3D reconstruction Goukenleuque et al. ‘00, Iro et al. ‘05 Plan-parallel (Feautrier) CE Gas + dust 1D, hydrostatic Seager et al. ‘98, ‘00, ‘05 Radiative gradient from RT models - - Local 3D hydrodynamics, winds Showman & Guillot ‘02 - - - Global 2D (single layered) hydrodynamics, rotation Cho et al. ‘96, ‘01, ‘03, ‘07 Menou ‘03 3D (Feautrier) CE Gas + dust Local 3D Hydrodynamics, winds Freytag et al. ‘09 CE, Photo-ionization Photochemistry Gas + dust Ray tracing, hydrostatic Ad-hoc rotation Brown ‘01, Tinetti et al. ‘08 Diffusion approximation CE Dust only Global 3D hydrodynamics, rotation Dobbs-Dixon & Lin ‘07 Plan-parallel, two-stream, NO scattering CE by table interpolation Gas + dust 1D, hydrostatic Fortney et al. ‘05, ‘06 Plan-parallel, ALI CE Gas + dust 1D, hydrostatic Sudarsky etal. ‘03,‘05,‘06 Burrows etal.‘03,’04,’05,’06 opacities Gas + dust Spherical symmetry, ALI CE, NLTE, Photo-ionization 1D, hydrostatic Global 3D reconstruction Barman et al. ‘01, ‘05, ‘06 Barman ‘08 radiative transfer chemistry geometry authors
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