1 Pau Amaro Seoane - modest 15-s
... of turbulent molecular clouds. The stars are assumed to form in the densest regions in the collapsing cloud after an initial free-fall times of the molecular cloud. The dynamical evolution of these stellar distributions are continued by means of direct N-body simulations. The molecular clouds typica ...
... of turbulent molecular clouds. The stars are assumed to form in the densest regions in the collapsing cloud after an initial free-fall times of the molecular cloud. The dynamical evolution of these stellar distributions are continued by means of direct N-body simulations. The molecular clouds typica ...
![The P Cygni supergiant [OMN2000] LS1](http://s1.studyres.com/store/data/014882705_1-5f78b60dc5267f0c5ad35fc8d810ae0e-300x300.png)
The P Cygni supergiant [OMN2000] LS1
... close to the photosphere. In such a situation any He/H ratio may fit the observations with an appropiate scaling of the mass loss rate and a small variation of the stellar temperature; this effect is observed in e.g. HD316285 (see Hillier et al. 1998 for a discussion). However, unlike this star, the ...
... close to the photosphere. In such a situation any He/H ratio may fit the observations with an appropiate scaling of the mass loss rate and a small variation of the stellar temperature; this effect is observed in e.g. HD316285 (see Hillier et al. 1998 for a discussion). However, unlike this star, the ...
1 - University of Arizona
... images probe the circumstellar environments as close as 0.3" from the target stars and are shedding light on the spatial distribution of the dust in these systems. In most cases, the IR excess was determined by detection at only one wavelength band (typically 60m), and therefore constructing anythi ...
... images probe the circumstellar environments as close as 0.3" from the target stars and are shedding light on the spatial distribution of the dust in these systems. In most cases, the IR excess was determined by detection at only one wavelength band (typically 60m), and therefore constructing anythi ...
the challenge of wide-field transit surveys: the case of
... for the primary star. In addition, we wanted to confirm the stellar parameters derived from the low-resolution CfA spectra that were already available at that time. We obtained off-transit BV(RI )C exposures on 2004 March 26 and in-transit BV IC exposures on 2004 March 27 ( UT dates) with the Lowell ...
... for the primary star. In addition, we wanted to confirm the stellar parameters derived from the low-resolution CfA spectra that were already available at that time. We obtained off-transit BV(RI )C exposures on 2004 March 26 and in-transit BV IC exposures on 2004 March 27 ( UT dates) with the Lowell ...
Kathy Geise `08 - DU Portfolio
... The stellar atmosphere contains the outermost layers of the star and includes the region from which photons escape the star and become visible. Particles in the stellar atmosphere are not completely ionized and the temperature, pressure and density are much lower than in the interior. Stars are so l ...
... The stellar atmosphere contains the outermost layers of the star and includes the region from which photons escape the star and become visible. Particles in the stellar atmosphere are not completely ionized and the temperature, pressure and density are much lower than in the interior. Stars are so l ...
L95 IRON-RICH EJECTA IN THE SUPERNOVA
... availability of atomic data. This is the case to a greater or lesser extent for all NEI spectral models currently available. Typically with such models, the fitted Fe abundance is low, while the abundances of Ne and Mg, whose K-shell lines fall in this energy band, are enhanced to compensate for def ...
... availability of atomic data. This is the case to a greater or lesser extent for all NEI spectral models currently available. Typically with such models, the fitted Fe abundance is low, while the abundances of Ne and Mg, whose K-shell lines fall in this energy band, are enhanced to compensate for def ...
Radiatively driven Rayleigh-Taylor instability candidates around a
... denser gaseous matter (heavy fluid) surrounding the star. The optically thin gaps in between the RTI allowed radiation to escape, and the overdense material falls back to the disk plane. On largers scales, infalling gas is thought to strike the walls of the outflow cavity bubble, which effectively sl ...
... denser gaseous matter (heavy fluid) surrounding the star. The optically thin gaps in between the RTI allowed radiation to escape, and the overdense material falls back to the disk plane. On largers scales, infalling gas is thought to strike the walls of the outflow cavity bubble, which effectively sl ...
Pulsar slow glitches in a solid quark star model
... pulsar is the change in its period known as slow glitches. Different from the typical feature of glitch phenomenon of other pulsars, this pulsar shows glitches that have rather slow increase in spin frequency, with a time scale of 200-300 days (while the normal glitches experience this process much ...
... pulsar is the change in its period known as slow glitches. Different from the typical feature of glitch phenomenon of other pulsars, this pulsar shows glitches that have rather slow increase in spin frequency, with a time scale of 200-300 days (while the normal glitches experience this process much ...
Gaseous Planets, Protostars And Young Brown Dwarfs
... mean Rosseland opacity. The planet surface radius is essentially fixed by the accretion shock conditions (see e.g. Fig. 1d of Hubickyj et al., 2005). This value, however, remains highly uncertain, as its correct determination would imply a proper treatment of the radiative shock. In A05, phase (i) i ...
... mean Rosseland opacity. The planet surface radius is essentially fixed by the accretion shock conditions (see e.g. Fig. 1d of Hubickyj et al., 2005). This value, however, remains highly uncertain, as its correct determination would imply a proper treatment of the radiative shock. In A05, phase (i) i ...
Test Ch. 27 Multiple Choice Identify the choice that best completes
... 37. The true brightness of a star is called its ____________________. 38. Scientists continue to divide the sky into sectors using star patterns called ...
... 37. The true brightness of a star is called its ____________________. 38. Scientists continue to divide the sky into sectors using star patterns called ...
Metallicity maps
... but ram-pressure stripping is very important), they yield different metal distributions and have different time scales ram-pressure in the outskirts of clusters is sufficient to strip gas and form new stars inhomogeneous metallicity distribution, enriched material is not mixed immediately with I ...
... but ram-pressure stripping is very important), they yield different metal distributions and have different time scales ram-pressure in the outskirts of clusters is sufficient to strip gas and form new stars inhomogeneous metallicity distribution, enriched material is not mixed immediately with I ...
Abstract - UChicago High Energy Physics
... [10, 11] above disks can be home to nucleosynthesis, including perhaps the r-process, depending on neutrino flavor composition [2, 9, 12–16]. The neutrino flavor composition above the neutrino trapping surface depends not only on thermodynamics in the trapped regions, but also the oscillation of neu ...
... [10, 11] above disks can be home to nucleosynthesis, including perhaps the r-process, depending on neutrino flavor composition [2, 9, 12–16]. The neutrino flavor composition above the neutrino trapping surface depends not only on thermodynamics in the trapped regions, but also the oscillation of neu ...
ASTROPHYSICAL PARAMETERS OF LS 2883 AND IMPLICATIONS FOR THE Y egueruela ,
... Only a few binary systems with compact objects display TeV emission. The physical properties of the companion stars represent basic input for understanding the physical mechanisms behind the particle acceleration, emission, and absorption processes in these so-called gamma-ray binaries. Here we pres ...
... Only a few binary systems with compact objects display TeV emission. The physical properties of the companion stars represent basic input for understanding the physical mechanisms behind the particle acceleration, emission, and absorption processes in these so-called gamma-ray binaries. Here we pres ...
11.3 MB PDF file
... (distance between overlapping orders) of 4.4 A. Profiles such as this allow us to study the Doppler broadening in H I1 regions, to detect line splitting, etc. From the photometric point of view, one advantage of observing the profile of each line is that we can detect unwanted night-sky emissions. B ...
... (distance between overlapping orders) of 4.4 A. Profiles such as this allow us to study the Doppler broadening in H I1 regions, to detect line splitting, etc. From the photometric point of view, one advantage of observing the profile of each line is that we can detect unwanted night-sky emissions. B ...
Discovery of Warm and Dense Molecular Gas Surrounding the Ring
... mapped in several 4 0 ; 4 0 fields around G79.29+0.46, using onthe-fly mode, with a fixed position (empty of line emission) as the reference. Several on-the-fly maps were later averaged in order to get a final rms as low as possible. The scanning directions and starting positions were different eac ...
... mapped in several 4 0 ; 4 0 fields around G79.29+0.46, using onthe-fly mode, with a fixed position (empty of line emission) as the reference. Several on-the-fly maps were later averaged in order to get a final rms as low as possible. The scanning directions and starting positions were different eac ...
PDF only
... We thus see how observations of several properties of pulsars point to quite extraordinary objects from the astrophysical point of view: stars with a mass similar to that of the Sun but constrained by gravity in a sphere with diameter of about 20-30 kilometers, spinning around their axis up to a tho ...
... We thus see how observations of several properties of pulsars point to quite extraordinary objects from the astrophysical point of view: stars with a mass similar to that of the Sun but constrained by gravity in a sphere with diameter of about 20-30 kilometers, spinning around their axis up to a tho ...
The Formation of a Realistic Disk Galaxy in Lambda Dominated
... Two main SPH simulations were run, one for each cosmology. Both runs included Compton and radiative cooling, assuming a gas of primordial composition; and star formation and SN (Types I and II) feedback, treated following the prescription described by Katz (1992), in which stars spawn from cold, Jea ...
... Two main SPH simulations were run, one for each cosmology. Both runs included Compton and radiative cooling, assuming a gas of primordial composition; and star formation and SN (Types I and II) feedback, treated following the prescription described by Katz (1992), in which stars spawn from cold, Jea ...
Determining the mass loss limit for close
... for blow-off in the case of the classic Newtonian gravitational potential. For very massive or Jupiter-class exoplanets exposed to less intense stellar XUV fluxes at orbital distances > 0.15 AU the exobase temperatures can be lower than the critical temperature for the onset of the blow-off. This wi ...
... for blow-off in the case of the classic Newtonian gravitational potential. For very massive or Jupiter-class exoplanets exposed to less intense stellar XUV fluxes at orbital distances > 0.15 AU the exobase temperatures can be lower than the critical temperature for the onset of the blow-off. This wi ...
Aldebaran
... nuclear reaction in its atoms. When the gases and dust of the nebula contracted, a protostar was formed. Gravity caused the protostar to condense further and heat up. Nuclear reactions occurred when the temperature in the center of the protostar reached about 10 million degrees, and the star was bor ...
... nuclear reaction in its atoms. When the gases and dust of the nebula contracted, a protostar was formed. Gravity caused the protostar to condense further and heat up. Nuclear reactions occurred when the temperature in the center of the protostar reached about 10 million degrees, and the star was bor ...
neutron star
... BLACK HOLE VERIFICATION • We need to measure mass by: — Using orbital properties of a companion — Measuring the velocity and distance of orbiting gas ...
... BLACK HOLE VERIFICATION • We need to measure mass by: — Using orbital properties of a companion — Measuring the velocity and distance of orbiting gas ...
VLT identifications in the Chandra/XMM
... sion lines and high-excitation lines indicating photoionization by a hard continuum source. However, already in the spectroscopic identifications of the ROSAT Deep Surveys it became apparent, that an increasing fraction of faint X-ray selected AGN shows a significant, sometimes dominant contribution ...
... sion lines and high-excitation lines indicating photoionization by a hard continuum source. However, already in the spectroscopic identifications of the ROSAT Deep Surveys it became apparent, that an increasing fraction of faint X-ray selected AGN shows a significant, sometimes dominant contribution ...
Discovery of concentric broken rings at sub
... concentric ringlets and at least one spiral arm. Finally, the VISIR data at 8.6 µm suggests the presence of an additional dust population closer in. Besides, we do not detect companions more massive than 1–3 mass of Jupiter. Conclusions. The performance of SPHERE allows us to resolve the extended du ...
... concentric ringlets and at least one spiral arm. Finally, the VISIR data at 8.6 µm suggests the presence of an additional dust population closer in. Besides, we do not detect companions more massive than 1–3 mass of Jupiter. Conclusions. The performance of SPHERE allows us to resolve the extended du ...
The ages of pre-main-sequence stars
... can be very misleading, because it is significantly (generally different by a factor of 2 to 5) dependent on the accretion rate and, for ages less than about 106 yr, the initial state of the star. We present a number of accreting protostellar tracks that can be used to determine age if the initial c ...
... can be very misleading, because it is significantly (generally different by a factor of 2 to 5) dependent on the accretion rate and, for ages less than about 106 yr, the initial state of the star. We present a number of accreting protostellar tracks that can be used to determine age if the initial c ...
The Milky Way thin disk structure as revealed by stars and young
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.