PH607 – Galaxies 2
... monitored. However, in spite of all efforts, no unambiguous NIR counterpart of SgrA* could be detected up to 2003. On the 9th of May, during routine observations of the GC star cluster at 1.7 microns with NAOS/CONICA at the VLT, we witnessed a powerful flare at the location of the black hole. Within ...
... monitored. However, in spite of all efforts, no unambiguous NIR counterpart of SgrA* could be detected up to 2003. On the 9th of May, during routine observations of the GC star cluster at 1.7 microns with NAOS/CONICA at the VLT, we witnessed a powerful flare at the location of the black hole. Within ...
Chapter 17
... 17. The "orbits" of the stars in our galaxy do not follow the laws of Kepler. We understand this to be due to: A. proportionally more mass distributed away from the galactic center. B. angular momentum is not being conserved as the Galaxy rotates. C. his laws are supplanted by Einstein's relativity. ...
... 17. The "orbits" of the stars in our galaxy do not follow the laws of Kepler. We understand this to be due to: A. proportionally more mass distributed away from the galactic center. B. angular momentum is not being conserved as the Galaxy rotates. C. his laws are supplanted by Einstein's relativity. ...
Practice Questions for Final
... Which of the following does NOT support the theory that active galactic nuclei are powered by accretion disks around massive black holes? A. Spectral lines from the galactic center indicate that clouds of gas are orbiting a central object at very high speed. B. The total amount of radiation coming f ...
... Which of the following does NOT support the theory that active galactic nuclei are powered by accretion disks around massive black holes? A. Spectral lines from the galactic center indicate that clouds of gas are orbiting a central object at very high speed. B. The total amount of radiation coming f ...
A105 Stars and Galaxies
... super-massive black hole at its center! “A supermassive black hole at the center of our galaxy is adequate to explain the observations that have been seen.” ...
... super-massive black hole at its center! “A supermassive black hole at the center of our galaxy is adequate to explain the observations that have been seen.” ...
ONLINE practice exam
... 4. (a) How long ago did the light leave its source for an object with a redshift z = 0.05, if the Hubble constant were 60 km sec-1 Mpc-1? (Assume nonrelativistic speed for this object.) (b) If we (somewhat erroneously) assume that the expansion rate of the universe has been constant over all time, a ...
... 4. (a) How long ago did the light leave its source for an object with a redshift z = 0.05, if the Hubble constant were 60 km sec-1 Mpc-1? (Assume nonrelativistic speed for this object.) (b) If we (somewhat erroneously) assume that the expansion rate of the universe has been constant over all time, a ...
Positions in the Solar System
... collapsed million own years gravity. after As the it did Big so, Bang, the matter thelarger gas star began to form. This star grew or stuck together to form the became contained within and dense it began enough to move for the inmore aforming first giant and larger as it collected more and of The st ...
... collapsed million own years gravity. after As the it did Big so, Bang, the matter thelarger gas star began to form. This star grew or stuck together to form the became contained within and dense it began enough to move for the inmore aforming first giant and larger as it collected more and of The st ...
Position in Solar System ppt
... collapsed million own years gravity. after As the it did Big so, Bang, the matter thelarger gas star began to form. This star grew or stuck together to form the became contained within and dense it began enough to move for the inmore aforming first giant and larger as it collected more and of The st ...
... collapsed million own years gravity. after As the it did Big so, Bang, the matter thelarger gas star began to form. This star grew or stuck together to form the became contained within and dense it began enough to move for the inmore aforming first giant and larger as it collected more and of The st ...
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.