GALEX and Star Formation
... complexes and stellar associations dissolve. They are very hot, therefore the UV wavelength range is ideal to detect and study them, because (i) UV colors are more sensitive to the temperatures of the hottest stars, enabling e.g. to discern O-types from late-O/early-B, while optical colors are satur ...
... complexes and stellar associations dissolve. They are very hot, therefore the UV wavelength range is ideal to detect and study them, because (i) UV colors are more sensitive to the temperatures of the hottest stars, enabling e.g. to discern O-types from late-O/early-B, while optical colors are satur ...
OBSERVATIONS OF PHYSICAL PROCESSES IN
... cluster galaxies (BCGs) of those clusters. It has been known for a while that the state of the hot intracluster medium (ICM) gas in the core of a galaxy cluster, quantified as the central entropy of the gas, can be found in two particular states. Galaxy clusters with central entropies greater than 3 ...
... cluster galaxies (BCGs) of those clusters. It has been known for a while that the state of the hot intracluster medium (ICM) gas in the core of a galaxy cluster, quantified as the central entropy of the gas, can be found in two particular states. Galaxy clusters with central entropies greater than 3 ...
A new view of galaxy evolution
... relaxation over a relatively quick timescale. However, the question remains as to how and why these galaxies look the way they do in the distant universe; specifically, we need to understand how they got distorted in the first place. Furthermore, kinematic studies of these galaxies show that they of ...
... relaxation over a relatively quick timescale. However, the question remains as to how and why these galaxies look the way they do in the distant universe; specifically, we need to understand how they got distorted in the first place. Furthermore, kinematic studies of these galaxies show that they of ...
Hubble Space Telescope Imaging of Post
... burst of star formation followed by a rapid truncation on the order of ∼ 0.1 − 0.4 Gyr. This rapid truncation may be due to the rapid consumption of fuel or it’s expulsion from the galaxy via AGN and/or supernova feedback. Observationally, post-starburst galaxies have been linked to mergers and AGN ...
... burst of star formation followed by a rapid truncation on the order of ∼ 0.1 − 0.4 Gyr. This rapid truncation may be due to the rapid consumption of fuel or it’s expulsion from the galaxy via AGN and/or supernova feedback. Observationally, post-starburst galaxies have been linked to mergers and AGN ...
the stebbins galaxy: the origins of interstellar medium studies
... globular clusters. The result of those measurements provided a three-dimensional distribution of the globular clusters from which he drew bold conclusions about the size and structure of our Galaxy. Assuming that the globular clusters form a symmetric halo around the center of the Galaxy, their appa ...
... globular clusters. The result of those measurements provided a three-dimensional distribution of the globular clusters from which he drew bold conclusions about the size and structure of our Galaxy. Assuming that the globular clusters form a symmetric halo around the center of the Galaxy, their appa ...
Suppose you tried to determine where we are in the galaxy by
... mass of the galaxy. b) True, the Milky Way's rotation curve stops increasing well before the orbit of the Sun, indicating that the majority of the Milky Way's mass lies within the Sun's orbit. c) False, the Milky Way's rotation curve remains flat well beyond the orbit of the Sun, indicating that t ...
... mass of the galaxy. b) True, the Milky Way's rotation curve stops increasing well before the orbit of the Sun, indicating that the majority of the Milky Way's mass lies within the Sun's orbit. c) False, the Milky Way's rotation curve remains flat well beyond the orbit of the Sun, indicating that t ...
Article PDF - IOPscience
... parameters directly measure the major current and past modes of galaxy formation and evolution. We discuss evidence that the concentration index traces the past evolutionary history of galaxies and potentially correlates with the fraction of stars produced through gas accreted from the intergalactic ...
... parameters directly measure the major current and past modes of galaxy formation and evolution. We discuss evidence that the concentration index traces the past evolutionary history of galaxies and potentially correlates with the fraction of stars produced through gas accreted from the intergalactic ...
Recent Star Formation in Nearby Early-type Galaxies
... them. This fraction is somewhat smaller than previously reported, but this is because Combes et al., contrary to earlier studies, also surveyed bright earlytype galaxies that have a relatively lower molecular gas content. All galaxies with CO emission show evidence of recent star formation in their ...
... them. This fraction is somewhat smaller than previously reported, but this is because Combes et al., contrary to earlier studies, also surveyed bright earlytype galaxies that have a relatively lower molecular gas content. All galaxies with CO emission show evidence of recent star formation in their ...
Elliptical Galaxies
... Dark haloes: mass at large radius Spiral galaxy rotation curves have been used to show that they are embedded in dark haloes that contain three to ten times as much mass as is visible in stars, gas and dust. Can dark haloes be detected in elliptical galaxies? The velocity dispersion in many galaxies ...
... Dark haloes: mass at large radius Spiral galaxy rotation curves have been used to show that they are embedded in dark haloes that contain three to ten times as much mass as is visible in stars, gas and dust. Can dark haloes be detected in elliptical galaxies? The velocity dispersion in many galaxies ...
sections 19-22 instructor notes
... establish likely distances to Galactic objects from their radial velocities, i.e. using the equations of Galactic motion. ...
... establish likely distances to Galactic objects from their radial velocities, i.e. using the equations of Galactic motion. ...
The cosmological significance of high
... could be as large as 6.5 kpc. Blitz et al. (1999) additionally pointed out that the velocity of Complex H is too large for it to be in circular rotation around the Galaxy at any distance. They further argued that the lack of any observational evidence for an interaction between Complex H and the int ...
... could be as large as 6.5 kpc. Blitz et al. (1999) additionally pointed out that the velocity of Complex H is too large for it to be in circular rotation around the Galaxy at any distance. They further argued that the lack of any observational evidence for an interaction between Complex H and the int ...
2007_spitzer_lecture_series_kennicutt_talk3
... H2 surface density, and not with HI density • A kinematic star formation law does not seem to extend as well to local scales • The disk-averaged SF law is confirmed with more/better observations. Some metal-poor galaxies lie systematically above the mean relation. ...
... H2 surface density, and not with HI density • A kinematic star formation law does not seem to extend as well to local scales • The disk-averaged SF law is confirmed with more/better observations. Some metal-poor galaxies lie systematically above the mean relation. ...
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.