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... Quasars are extremely distant objects in our known universe. They are the furthest objects away from our galaxy that can be seen. Quasars are extremely bright masses of energy and light. The name quasar is actually short for quasi-stellar radio source or quasi-stellar object. They are the brightest ...
... Quasars are extremely distant objects in our known universe. They are the furthest objects away from our galaxy that can be seen. Quasars are extremely bright masses of energy and light. The name quasar is actually short for quasi-stellar radio source or quasi-stellar object. They are the brightest ...
OUTFLOW INFALL AND ROTATION IN HIGH
... star can be detected up to: continuum sensitivity: d < 1.7 [Mstar(MO)]0.5 ~ 12 kpc line sensitivity: d < 6.2 Mstar(MO) sin2i/W2(km/s) ~ 8 kpc spectral + angular resolution: d < 14 Mstar(MO) sin2i/[D(’’)W2(km/s)] ~ ~ 19 kpc ...
... star can be detected up to: continuum sensitivity: d < 1.7 [Mstar(MO)]0.5 ~ 12 kpc line sensitivity: d < 6.2 Mstar(MO) sin2i/W2(km/s) ~ 8 kpc spectral + angular resolution: d < 14 Mstar(MO) sin2i/[D(’’)W2(km/s)] ~ ~ 19 kpc ...
Supermassive Black Holes and the Growth of Galaxies
... How do we observe black holes? Since black holes by definition cannot emit light, an obvious question is how do we observe them? While we cannot see black holes directly, we can observe how their strong gravitational fields influence the matter and gas around them. At present observations have revea ...
... How do we observe black holes? Since black holes by definition cannot emit light, an obvious question is how do we observe them? While we cannot see black holes directly, we can observe how their strong gravitational fields influence the matter and gas around them. At present observations have revea ...
Script Chapter 7 part 1
... collisionally ionized hot gas (components 2 and 5 in Table 7.1) fill most of the space in the Milky Way disk, while the molecular gas and the cool atomic gas (components 1 and 2) make up about 90 % of the baryonic mass. The molecular clouds and H II regions (components 2 and 3) are over-dense region ...
... collisionally ionized hot gas (components 2 and 5 in Table 7.1) fill most of the space in the Milky Way disk, while the molecular gas and the cool atomic gas (components 1 and 2) make up about 90 % of the baryonic mass. The molecular clouds and H II regions (components 2 and 3) are over-dense region ...
ppd_hia
... TW Hya: Evidence for “Pebbles” • 3.5 cm radio emission – not variable: weeks to years ...
... TW Hya: Evidence for “Pebbles” • 3.5 cm radio emission – not variable: weeks to years ...
Circular ac
... Lyra.[1][2] The planet was discovered by NASA's Kepler spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. NASA announced the confirmation of the exoplanet on 6 January 2015.[1] Although it is not habitable, as of June ...
... Lyra.[1][2] The planet was discovered by NASA's Kepler spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. NASA announced the confirmation of the exoplanet on 6 January 2015.[1] Although it is not habitable, as of June ...
PHYS3380_102815_bw - The University of Texas at Dallas
... - subsequently demonstrated that these objects were shockexcited nebulae. - shown that the large range of excitation conditions requires bow shocks and other complex morphologies. By the early 1980s, several Herbig-Haro (HH) objects shown to be highly collimated jets of partially ionized plasma movi ...
... - subsequently demonstrated that these objects were shockexcited nebulae. - shown that the large range of excitation conditions requires bow shocks and other complex morphologies. By the early 1980s, several Herbig-Haro (HH) objects shown to be highly collimated jets of partially ionized plasma movi ...
– 1 – 1. Chemical Evolution 1.1.
... suggests that the Salpeter IMF is too steep to fit the observations for low mass stars below 0.5M⊙ , and that a flatter slope is required, reaching −0.3 ± 0.7 for 0.01 < M/M⊙ < 0.08. Note that the transformation from luminosity to mass (the IMF is a function of stellar mass) is not as well determine ...
... suggests that the Salpeter IMF is too steep to fit the observations for low mass stars below 0.5M⊙ , and that a flatter slope is required, reaching −0.3 ± 0.7 for 0.01 < M/M⊙ < 0.08. Note that the transformation from luminosity to mass (the IMF is a function of stellar mass) is not as well determine ...
D109-08x
... apart as it races at 4.5 million miles per hour through the heart of a distant cluster of galaxies. The images, taken over several wavelengths, provide evidence of the "galactic assault and battery," namely, gas being stripped from the doomed galaxy, called C153. The composite photograph at left was ...
... apart as it races at 4.5 million miles per hour through the heart of a distant cluster of galaxies. The images, taken over several wavelengths, provide evidence of the "galactic assault and battery," namely, gas being stripped from the doomed galaxy, called C153. The composite photograph at left was ...
LL_starsCatalog
... Note that each Set method is overloaded so that they may be called with numeric or character parameters. Your program does not have to call both of these but it is good to include them both so that they are available to be used. The application must use an unordered linked list to hold all the stars ...
... Note that each Set method is overloaded so that they may be called with numeric or character parameters. Your program does not have to call both of these but it is good to include them both so that they are available to be used. The application must use an unordered linked list to hold all the stars ...
3D maps of the local interstellar medium: searching for the imprints
... of a Bayesian technique devised by Vergely (2001), to produce a 3D distribution of differential reddening (Lallement et al, 2014). Figure 1 is a horizontal cut in the computed 3D distribution, here along the Galactic plane. Due to the limited dataset, a spatial correlation length must be imposed dur ...
... of a Bayesian technique devised by Vergely (2001), to produce a 3D distribution of differential reddening (Lallement et al, 2014). Figure 1 is a horizontal cut in the computed 3D distribution, here along the Galactic plane. Due to the limited dataset, a spatial correlation length must be imposed dur ...
pasta Jos´e A. Pons , Daniele Vigan`o and Nanda Rea
... In the absence of a more detailed microscopical calculation, we can use the impurity parameter formalism as a first simplified approximation to the complex calculation of the resistivity. The impurity parameter, Qimp , is a measure of the distribution of the nuclide charge numbers in the crust mate ...
... In the absence of a more detailed microscopical calculation, we can use the impurity parameter formalism as a first simplified approximation to the complex calculation of the resistivity. The impurity parameter, Qimp , is a measure of the distribution of the nuclide charge numbers in the crust mate ...
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... All other stellar masses are from binaries except for a few gravitational redshifts for white dwarfs. The problems of binaries are: we only see the orbit projected onto the sky, not the full 3D orbit, and we do not know the inclination angle, the angle that the orbital plane makes with the plane of ...
... All other stellar masses are from binaries except for a few gravitational redshifts for white dwarfs. The problems of binaries are: we only see the orbit projected onto the sky, not the full 3D orbit, and we do not know the inclination angle, the angle that the orbital plane makes with the plane of ...
Les Houches 1996 Winter School
... For AS 207A, V2508 Oph, and PX Vul, simple flat accretion disk models suggest much smaller sizes (when fitted to SEDs) than those determined interferometrically. Models incorporating puffed-up inner walls and flared outer disks provide better fits to our V2 and SED data than the simple flat disk mod ...
... For AS 207A, V2508 Oph, and PX Vul, simple flat accretion disk models suggest much smaller sizes (when fitted to SEDs) than those determined interferometrically. Models incorporating puffed-up inner walls and flared outer disks provide better fits to our V2 and SED data than the simple flat disk mod ...
Shape of a slowly rotating star measured by asteroseismology
... projected shape of the rapidly rotating A star Altair has been observed with infrared interferometry to have a flattening DR/R = 0.14 ± 0.03 (6, 7). Vega, another rapidly rotating A star, has an apparent deformation that is too small to be measured because it is seen almost pole-on (8). Here, we pre ...
... projected shape of the rapidly rotating A star Altair has been observed with infrared interferometry to have a flattening DR/R = 0.14 ± 0.03 (6, 7). Vega, another rapidly rotating A star, has an apparent deformation that is too small to be measured because it is seen almost pole-on (8). Here, we pre ...
Review: How does a star`s mass determine its life story?
... – It is a ball of neutrons left over from a massive star supernova and supported by neutron degeneracy pressure. ...
... – It is a ball of neutrons left over from a massive star supernova and supported by neutron degeneracy pressure. ...
Quasars- The Brightest Black Holes
... all quasars are variable in their brightness. Today we know that only about 10% of quasars have the strong radio emission – most have none. Surveys (using observations taken in a range of wavebands) are continually identifying and collecting more and more quasars to the present day – hundreds of tho ...
... all quasars are variable in their brightness. Today we know that only about 10% of quasars have the strong radio emission – most have none. Surveys (using observations taken in a range of wavebands) are continually identifying and collecting more and more quasars to the present day – hundreds of tho ...
Radiation vs. Gas Pressure, the Stellar Mass
... To me, there are two key conclusions from the above: 1. Simple scalings from stellar structure imply that stars near or above 100 M⊙ must inevitably be near the Eddington limit, with radiation pressure dominating over gas pressure in the stellar envelope. 2. However, the Eddington limit itself acts ...
... To me, there are two key conclusions from the above: 1. Simple scalings from stellar structure imply that stars near or above 100 M⊙ must inevitably be near the Eddington limit, with radiation pressure dominating over gas pressure in the stellar envelope. 2. However, the Eddington limit itself acts ...
12.1 Introduction
... gas. It is therefore inevitable that stars evolve with time. In the next few lectures we shall look in some detail at the process of stellar evolution. Stellar evolution, as opposed to equilibrium, can be reproduced in our computers by solving a series of equilibrium stellar models—normally referre ...
... gas. It is therefore inevitable that stars evolve with time. In the next few lectures we shall look in some detail at the process of stellar evolution. Stellar evolution, as opposed to equilibrium, can be reproduced in our computers by solving a series of equilibrium stellar models—normally referre ...
The APEX Telescope Large Area Survey of the Galaxy (ATLASGAL)
... current data cover the ± 60° range in Galactic longitude, over ± 1.5° in latitude (see Figure 1). To complete the coverage of the most active regions in the inner Galaxy, another small programme was accepted in 2010. Observations of the – 80° to – 60° range in longitude are still ongoing. The telesc ...
... current data cover the ± 60° range in Galactic longitude, over ± 1.5° in latitude (see Figure 1). To complete the coverage of the most active regions in the inner Galaxy, another small programme was accepted in 2010. Observations of the – 80° to – 60° range in longitude are still ongoing. The telesc ...
mass loss of massive stars - of /proceedings
... Although short, the RSG phase strongly impacts on the neighbouring environment. In that phase, mass loss rates range from 10−7 to 10−4 M and the wind velocities are typically of 10 to 40 km s−1 . Hence, the wind density is about a thousand times larger than in the OB phase. Fig. 2 shows mass loss r ...
... Although short, the RSG phase strongly impacts on the neighbouring environment. In that phase, mass loss rates range from 10−7 to 10−4 M and the wind velocities are typically of 10 to 40 km s−1 . Hence, the wind density is about a thousand times larger than in the OB phase. Fig. 2 shows mass loss r ...
Chapter 27 Quasars, Active Galaxies, and Gamma
... • Early radio telescopes found radio emission from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like stars. ...
... • Early radio telescopes found radio emission from stars, nebulae, and some galaxies. • There were also point-like, or star-like, radio sources which varied rapidly these are the `quasi-stellar’ radio sources or quasars. • In visible light quasars appear as points, like stars. ...
FEEDBACK IN THE LOCAL UNIVERSE: The
... radio source has returned upwards of 1061 erg to regions of the cluster that extend even beyond the cooling radius. Note the strong spatial anti-correlation of the radio source (in pink) with the X-ray cavities (in blue). Such correspondence is typical of cool core clusters with cavities and extende ...
... radio source has returned upwards of 1061 erg to regions of the cluster that extend even beyond the cooling radius. Note the strong spatial anti-correlation of the radio source (in pink) with the X-ray cavities (in blue). Such correspondence is typical of cool core clusters with cavities and extende ...
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.