Chapter 17
... 11. Blazars are more luminous and fluctuate much more rapidly than both type 1 and type 2 Seyfert galaxies. How does the unified model of an AGN’s supermassive black holes and accretion disk explain these differences? a. Blazars and Seyfert galaxies are different views of the accretion disk of an AG ...
... 11. Blazars are more luminous and fluctuate much more rapidly than both type 1 and type 2 Seyfert galaxies. How does the unified model of an AGN’s supermassive black holes and accretion disk explain these differences? a. Blazars and Seyfert galaxies are different views of the accretion disk of an AG ...
Hubble`s Law Lab - The University of Texas at Austin
... giant elliptical galaxies to do his work because these galaxies have a smooth, regular shape that is easy to measure. Astronomers know that, on average, all giant elliptical galaxies have about the same size. The galaxies you have measured in this lab look smaller or larger because they are at diffe ...
... giant elliptical galaxies to do his work because these galaxies have a smooth, regular shape that is easy to measure. Astronomers know that, on average, all giant elliptical galaxies have about the same size. The galaxies you have measured in this lab look smaller or larger because they are at diffe ...
Lecture notes 18: Galaxies and galaxy clusters
... first to recocnize the possibility that the Milky Way was indeed a stellar disk where the Sun was but one of many. Kant went on to propose that if the Milky Way were limited then perhaps the diffuse “elliptical nebulae” seen in the night sky may also be distant disklike systems similar to our own but ...
... first to recocnize the possibility that the Milky Way was indeed a stellar disk where the Sun was but one of many. Kant went on to propose that if the Milky Way were limited then perhaps the diffuse “elliptical nebulae” seen in the night sky may also be distant disklike systems similar to our own but ...
Moitinho et al. - Wiley Online Library
... seem to form an elongated structure between l = 230◦ and l = 250◦ , stretching toward the outer Galaxy. We interpret this structure as the probable extension of the local (Orion) arm in the third quadrant. It appears that the Orion arm stretches outward, reaching and crossing the Perseus arm. Despit ...
... seem to form an elongated structure between l = 230◦ and l = 250◦ , stretching toward the outer Galaxy. We interpret this structure as the probable extension of the local (Orion) arm in the third quadrant. It appears that the Orion arm stretches outward, reaching and crossing the Perseus arm. Despit ...
Lecture 3 - University of Washington
... sphere) and Jaffe’s spheres. The latter has almost identical light profile as de Vaucouleurs profile, but the density law and gravitational potential are analytic: ...
... sphere) and Jaffe’s spheres. The latter has almost identical light profile as de Vaucouleurs profile, but the density law and gravitational potential are analytic: ...
Stellar populations
... • Typically they contain a few hundred stars • The stars are coeval (of same age), at essentially same distance and of same metallicity • There is a spread in star masses (given by IMF) ...
... • Typically they contain a few hundred stars • The stars are coeval (of same age), at essentially same distance and of same metallicity • There is a spread in star masses (given by IMF) ...
Rotation Curves:
... seen out to larger distances (and the converse is true for objects that are fainter than average). • Any flux limited sample will contain more brighter-than average objects than fainter-than-average objects. • The “average” brightness for objects in the sample will be brighter than the true “average ...
... seen out to larger distances (and the converse is true for objects that are fainter than average). • Any flux limited sample will contain more brighter-than average objects than fainter-than-average objects. • The “average” brightness for objects in the sample will be brighter than the true “average ...
Messier 87
Messier 87 (also known as Virgo A or NGC 4486, and generally abbreviated to M87) is a supergiant elliptical galaxy in the constellation Virgo. One of the most massive galaxies in the local universe, it is notable for its large population of globular clusters—M87 contains about 12,000 compared to the 150-200 orbiting the Milky Way—and its jet of energetic plasma that originates at the core and extends outward at least 1,500 parsecs (4,900 light-years), travelling at relativistic speed. It is one of the brightest radio sources in the sky, and is a popular target for both amateur astronomy observations and professional astronomy study.French astronomer Charles Messier discovered M87 in 1781, cataloguing it as a nebulous feature while searching for objects that would confuse comet hunters. The second brightest galaxy within the northern Virgo Cluster, M87 is located about 16.4 million parsecs (53.5 million light-years) from Earth. Unlike a disk-shaped spiral galaxy, M87 has no distinctive dust lanes. Instead, it has an almost featureless, ellipsoidal shape typical of most giant elliptical galaxies, diminishing in luminosity with distance from the centre. Forming around one sixth of M87's mass, the stars in this galaxy have a nearly spherically symmetric distribution, their density decreasing with increasing distance from the core. At the core is a supermassive black hole, which forms the primary component of an active galactic nucleus. This object is a strong source of multiwavelength radiation, particularly radio waves. M87's galactic envelope extends out to a radius of about 150 kiloparsecs (490,000 light-years), where it has been truncated—possibly by an encounter with another galaxy. Between the stars is a diffuse interstellar medium of gas that has been chemically enriched by elements emitted from evolved stars.