The Fate of the X-ray Emitting Gas in the Early
... Velocity dispersion of the GMAs is 122 km s-1, which is less than the stellar velocity dispersion of 237 km s-1. Several GMAs are likely on infalling, nearly radial orbits No disk-like structures GMAs have a nearly azimuthially symmetric distribution Mass deposition rate is 25 times greate ...
... Velocity dispersion of the GMAs is 122 km s-1, which is less than the stellar velocity dispersion of 237 km s-1. Several GMAs are likely on infalling, nearly radial orbits No disk-like structures GMAs have a nearly azimuthially symmetric distribution Mass deposition rate is 25 times greate ...
Slide 1
... Stellar Magnitude (brightness) Magnitude is the degree of brightness of a star. In 1856, British astronomer Norman Pogson proposed a quantitative scale of stellar magnitudes, which was adopted by the astronomical community. Each increment in magnitude corresponds to an increase in the amount of ene ...
... Stellar Magnitude (brightness) Magnitude is the degree of brightness of a star. In 1856, British astronomer Norman Pogson proposed a quantitative scale of stellar magnitudes, which was adopted by the astronomical community. Each increment in magnitude corresponds to an increase in the amount of ene ...
005 Astrophysics problems
... When the Apollo 11 satellite took the first men to the Moon in 1969 its trajectory was very closely monitored. The satellite had a velocity of 5374 m s-1 when 26306 km from the centre of the Earth and this had dropped to 3560 m s-1 when it was 54368 km from the centre of the Earth. The rocket motors ...
... When the Apollo 11 satellite took the first men to the Moon in 1969 its trajectory was very closely monitored. The satellite had a velocity of 5374 m s-1 when 26306 km from the centre of the Earth and this had dropped to 3560 m s-1 when it was 54368 km from the centre of the Earth. The rocket motors ...
part iv: stars i
... sequence; cf. Section 10.7), it must be the case that the Eddington Luminosity imposes an upper limit to the mass of stable stars. (In practice, instabilities cause a super-Eddington atmosphere to become clumpy, or `porous', and radiation is able to escape through paths of lowered optical depth betw ...
... sequence; cf. Section 10.7), it must be the case that the Eddington Luminosity imposes an upper limit to the mass of stable stars. (In practice, instabilities cause a super-Eddington atmosphere to become clumpy, or `porous', and radiation is able to escape through paths of lowered optical depth betw ...
The Milky Way
... Dark – it doesn’t produce light (any kind) Does have mass, produces gravity Nature is unknown Might be normal matter in a form that doesn’t emit much light – very small and dim star, little black holes • More likely it is elementary particles other than normal matter ...
... Dark – it doesn’t produce light (any kind) Does have mass, produces gravity Nature is unknown Might be normal matter in a form that doesn’t emit much light – very small and dim star, little black holes • More likely it is elementary particles other than normal matter ...
Implies dark halo for self-enrichment
... MV ~ -1.5, M* ~ 600 M, distance of ~25kpc, half-light radius ~ 30pc (?), velocity dispersion ~ 4 km/s (?), derived mass within half-light radius ~ 3 x 105M(?), M/L ~ 2000 (?), again <ρ>DM ~ 0.1 M/pc3 and high collapse redshift ...
... MV ~ -1.5, M* ~ 600 M, distance of ~25kpc, half-light radius ~ 30pc (?), velocity dispersion ~ 4 km/s (?), derived mass within half-light radius ~ 3 x 105M(?), M/L ~ 2000 (?), again <ρ>DM ~ 0.1 M/pc3 and high collapse redshift ...
PPT - El Camino College
... Eventually core runs out of hydrogen. What did the core need fusion for? What will happen to it as a result of losing fusion? What happens to gas balls when they shrink? What happens to the temperature of the material ...
... Eventually core runs out of hydrogen. What did the core need fusion for? What will happen to it as a result of losing fusion? What happens to gas balls when they shrink? What happens to the temperature of the material ...
Pulsars
... • Pulsating X-ray sources / X-ray pulsators - compact objects (generally neutron stars) in binary systems Accrete matter from normal star companion (P ~ 10s, dP/dt < 0) ...
... • Pulsating X-ray sources / X-ray pulsators - compact objects (generally neutron stars) in binary systems Accrete matter from normal star companion (P ~ 10s, dP/dt < 0) ...
Word doc - UC-HiPACC - University of California, Santa Cruz
... was so bright because that point of origin is actually five times closer to the Milky Way than typical long-duration gamma-ray bursts monitored by Swift, which are from galaxies that are now more than 17 billion light years away from us (thanks to the faster-than-light expansion of the distant unive ...
... was so bright because that point of origin is actually five times closer to the Milky Way than typical long-duration gamma-ray bursts monitored by Swift, which are from galaxies that are now more than 17 billion light years away from us (thanks to the faster-than-light expansion of the distant unive ...
X-ray polarimetry in Xenon gas filled detectors
... azimuthal angles relative to the polarization direction, β is the dipole asymmetry parameter and P2 is the 2nd Legendre polynomial) Derevianko et. al., At.Dat.Nucl.Dat. Tables 73 (1999) 153 ...
... azimuthal angles relative to the polarization direction, β is the dipole asymmetry parameter and P2 is the 2nd Legendre polynomial) Derevianko et. al., At.Dat.Nucl.Dat. Tables 73 (1999) 153 ...
Today`s Powerpoint
... - contains young and old stars, gas, dust. Has spiral structure - vertical thickness roughly 100 pc - 2 kpc (depending on component. Most gas and dust in thinner layer, most stars in thicker layer) ...
... - contains young and old stars, gas, dust. Has spiral structure - vertical thickness roughly 100 pc - 2 kpc (depending on component. Most gas and dust in thinner layer, most stars in thicker layer) ...
public_lector_10
... Lindblad interpreted the pattern of stellar motions as due to Galactic rotation ...
... Lindblad interpreted the pattern of stellar motions as due to Galactic rotation ...
Far Ultraviolet Spectroscopic Explorer
... Core-collapse SNRs (young SNRs from massive stars) Remnants from historical Supernovas in M83 ...
... Core-collapse SNRs (young SNRs from massive stars) Remnants from historical Supernovas in M83 ...
JimH This is Your Life - The Atlanta Astronomy Club
... • You can actually see the knots, called Herbig-Haro objects, in the jet move with time •They can have wind velocities of 200-300 km/s. This phase lasts about 10 million years. ...
... • You can actually see the knots, called Herbig-Haro objects, in the jet move with time •They can have wind velocities of 200-300 km/s. This phase lasts about 10 million years. ...
Gravitational Waves – detectors, sources & science
... • All such binaries emit GWs. Most sources are monochromatic – e.g., WD-WD binaries in our galaxy. • In very compact binaries, loss of energy to GWs leads to inspiral. Frequency of GWs increases with time – a “chirp”. ...
... • All such binaries emit GWs. Most sources are monochromatic – e.g., WD-WD binaries in our galaxy. • In very compact binaries, loss of energy to GWs leads to inspiral. Frequency of GWs increases with time – a “chirp”. ...
Star Clusters and Stellar Dynamics
... masses, since in most cases R << r.m.s.): open and globular star clusters, galaxies, clusters of galaxies • If 2-body interactions of stars are important in driving the dynamical evolution, the system is called collisional (star clusters); if stars are mainly moving in the collective gravitational ...
... masses, since in most cases R << r.m.s.): open and globular star clusters, galaxies, clusters of galaxies • If 2-body interactions of stars are important in driving the dynamical evolution, the system is called collisional (star clusters); if stars are mainly moving in the collective gravitational ...
Chapter 18 - Stars - University of New Mexico
... • With time, remaining gas loses energy by radiation, collapses, and spins up into a rotating disk. • Stars that form in the disk are younger and have coplanar orbits with primarily circular motions. • High metals, due to enriched gas from previous star formation. ...
... • With time, remaining gas loses energy by radiation, collapses, and spins up into a rotating disk. • Stars that form in the disk are younger and have coplanar orbits with primarily circular motions. • High metals, due to enriched gas from previous star formation. ...
Powerpoint
... Ionized helium. Requires extreme UV photons. Only hottest stars produce many of these. ...
... Ionized helium. Requires extreme UV photons. Only hottest stars produce many of these. ...
VISIT TO NORMAN LOCKYER OBSERVATORY IN SIDMOUTH
... To find it in the sky, follow the arc of the Plough's handle downwards to first find the orange star Arcturus and continue down to find the white, first magnitude star, Spica, in Virgo. Saturn, a little brighter than Spica, lies in Libra down to its lower left and will appear slightly yellow in colo ...
... To find it in the sky, follow the arc of the Plough's handle downwards to first find the orange star Arcturus and continue down to find the white, first magnitude star, Spica, in Virgo. Saturn, a little brighter than Spica, lies in Libra down to its lower left and will appear slightly yellow in colo ...
Introduction to black holes - Diarium
... Black holes are the result of the collapse of very complicated systems (e.g. stars) described by a large number of parameters. At the end the black hole only depends on three parameters M, Q, and J. Thus its entropy might “count” the number of ways in which a black hole can be made. Since the event ...
... Black holes are the result of the collapse of very complicated systems (e.g. stars) described by a large number of parameters. At the end the black hole only depends on three parameters M, Q, and J. Thus its entropy might “count” the number of ways in which a black hole can be made. Since the event ...
Vladimir_Sokolov
... (~0.01-100s), intense flashes of γ-rays (mostly subMeV) with enormous electromagnetic energy release up to ~1051-1054 ergs. The rapid temporal variability, δT ~<10 msec, observed in GRBs implies compact sources with a size smaller than ...
... (~0.01-100s), intense flashes of γ-rays (mostly subMeV) with enormous electromagnetic energy release up to ~1051-1054 ergs. The rapid temporal variability, δT ~<10 msec, observed in GRBs implies compact sources with a size smaller than ...
AST 301 Introduction to Astronomy - University of Texas Astronomy
... because the protons must be moving fast to get close enough together so they can be attracted by the strong force before their electrical repulsion pushes them apart. If the center of a star is too hot, fusion will run faster than energy is being radiated from the surface. But the high temperature w ...
... because the protons must be moving fast to get close enough together so they can be attracted by the strong force before their electrical repulsion pushes them apart. If the center of a star is too hot, fusion will run faster than energy is being radiated from the surface. But the high temperature w ...
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.