Related Research Articles
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek galaxias (γαλαξίας), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies.
Astronomy is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole.
A galaxy cluster, or a cluster of galaxies, is a structure that consists of anywhere from hundreds to thousands of galaxies that are bound together by gravity, with typical masses ranging from 1014 to 1015 solar masses. They are the second-largest known gravitationally bound structures in the universe after some superclusters (of which only one is known to be bound). They were believed to be the largest known structures in the universe until the 1980s, when superclusters were discovered. One of the key features of clusters is the intracluster medium (ICM). The ICM consists of heated gas between the galaxies and has a peak temperature between 2–15 keV that is dependent on the total mass of the cluster. Galaxy clusters should not be confused with galactic clusters (also known as open clusters), which are star clusters within galaxies, or with globular clusters, which typically orbit galaxies. Small aggregates of galaxies are referred to as galaxy groups rather than clusters of galaxies. The galaxy groups and clusters can themselves cluster together to form superclusters.
Sandra Moore Faber is an American astrophysicist known for her research on the evolution of galaxies. She is the University Professor of Astronomy and Astrophysics at the University of California, Santa Cruz, and works at the Lick Observatory. She has made discoveries linking the brightness of galaxies to the speed of stars within them and was the co-discoverer of the Faber–Jackson relation. Faber was also instrumental in designing the Keck telescopes in Hawaii.
The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area about 2.6 arcminutes on a side, about one 24-millionth of the whole sky, which is equivalent in angular size to a tennis ball at a distance of 100 metres. The image was assembled from 342 separate exposures taken with the Space Telescope's Wide Field and Planetary Camera 2 over ten consecutive days between December 18 and 28, 1995.
Marc Aaronson was an American astronomer.
I Zwicky 18 is a blue compact dwarf galaxy located about 59 million light years away in the constellation Ursa Major. The galaxy was first identified by Swiss astronomer Fritz Zwicky in a 1930s photographic survey of galaxies.
The Coma Cluster is a large cluster of galaxies that contains over 1,000 identified galaxies. Along with the Leo Cluster, it is one of the two major clusters comprising the Coma Supercluster. It is located in and takes its name from the constellation Coma Berenices.
Amy J. Barger is an American astronomer and Henrietta Leavitt Professor of Astronomy at the University of Wisconsin–Madison. She is considered a pioneer in combining data from multiple telescopes to monitor multiple wavelengths and in discovering distant galaxies and supermassive black holes, which are outside of the visible spectrum. Barger is an active member of the International Astronomical Union.
Alexei Vladimir "Alex" Filippenko is an American astrophysicist and professor of astronomy at the University of California, Berkeley. Filippenko graduated from Dos Pueblos High School in Goleta, California. He received a Bachelor of Arts in physics from the University of California, Santa Barbara in 1979 and a Ph.D. in astronomy from the California Institute of Technology in 1984, where he was a Hertz Foundation Fellow. He was a postdoctoral Miller Fellow at Berkeley from 1984 to 1986 and was appointed to Berkeley's faculty in 1986. In 1996 and 2005, he a Miller Research Professor, and he is currently a Senior Miller Fellow. His research focuses on supernovae and active galaxies at optical, ultraviolet, and near-infrared wavelengths, as well as on black holes, gamma-ray bursts, and the expansion of the Universe.
Smith's Cloud is a high-velocity cloud of hydrogen gas located in the constellation Aquila at Galactic coordinates l = 39°, b = −13°. The cloud was discovered in 1963 by Gail Bieger, née Smith, who was an astronomy student at Leiden University in the Netherlands.
Arthur Dodd Code was an astronomer who designed orbiting observatories.
Christopher J. Conselice is an astrophysicist who is Professor of Extragalactic Astronomy at the University of Manchester.
The George Darwin Lectureship is an award granted by the Royal Astronomical Society to a 'distinguished and eloquent speaker' on the subject of Astronomy including astrochemistry, astrobiology and astroparticle physics. The award is named after the astronomer George Darwin and has been given annually since 1984. The speaker may be based in the UK or overseas.
Wendy Laurel Freedman is a Canadian-American astronomer, best known for her measurement of the Hubble constant, and as director of the Carnegie Observatories in Pasadena, California, and Las Campanas, Chile. She is now the John & Marion Sullivan University Professor of Astronomy and Astrophysics at the University of Chicago. Her principal research interests are in observational cosmology, focusing on measuring both the current and past expansion rates of the universe, and on characterizing the nature of dark energy.
Warrick John Couch is an Australian professional astronomer. He is currently a professor at Swinburne University of Technology in Melbourne. He was previously the Director of Australia's largest optical observatory, the Australian Astronomical Observatory (AAO). He was also the president of the Australian Institute of Physics (2015–2017), and a non-executive director on the Board of the Giant Magellan Telescope Organization. He was a founding non-executive director of Astronomy Australia Limited.
Judith Gamora Cohen, is an American astronomer and the Kate Van Nuys Page Professor of Astronomy at the California Institute of Technology. She is a recognized expert regarding the Milky Way Galaxy, particularly with respect to the Galaxy's outer halo. She also played a key role in the design and construction of the Keck Telescope.
Alyson Brooks is an American theoretical astrophysicist and professor at Rutgers University. She uses large-scale simulations to determine how galaxies form.
The Peekaboo Galaxy is an irregular compact blue dwarf galaxy in the constellation Hydra. The galaxy is relatively small, at about 1,200 light-years (0.00037 Mpc) across. It is also relatively nearby, at a distance of around 22 million light-years (6.7 Mpc) from Earth. The Peekaboo Galaxy is considered one of the most metal-poor, least chemically enriched, and seemingly primordial, galaxies known.
References
- ↑ "Science Team". The Hubble Heritage Project. Space Telescope Science Institute. Retrieved 2008-12-04.
- ↑ Faber, S.M.; Gallager, J.S. (1979). "Masses and mass-to-light ratios of galaxies". Annual Review of Astronomy and Astrophysics. Palo Alto, California: Annual Reviews. 17: 135–187. Bibcode:1979ARA&A..17..135F. doi: 10.1146/annurev.aa.17.090179.001031 .