PGC 29820 | |
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![]() PGC 29820 imaged by the Hubble Space Telescope | |
Observation data (J2000 epoch) | |
Constellation | Sextans |
Right ascension | 10h 13m 46.82s |
Declination | -00d 54m 51.0s |
Redshift | 0.04244 |
Heliocentric radial velocity | 12,723 km/s |
Distance | 600 Mly (183.96 Mpc) |
Group or cluster | Abell 957 |
Apparent magnitude (V) | 0.11 |
Apparent magnitude (B) | 0.15 |
Characteristics | |
Type | Sb(f), Seyfert 2 |
Size | 120,000 ly |
Other designations | |
LEDA 29820, CGCG 008-077, 2dFGRS N288Z210, AGC 500048, NVSS J101346-005449, JO204 |
PGC 29820 ( known as JO204) is a spiral galaxy located 600 million light-years away from the Solar System in the Sextans constellation. [1] The galaxy is about 120,000 light-years in diameter and is a member of Abell 957, a low-mass galaxy cluster. [2] The first known reference to this galaxy is from volume I of the Catalogue of Galaxies and of Clusters of Galaxies compiled by Fritz Zwicky in 1961, where it was listed as CGCG 008-077. [3]
PGC 29820 is classified a massive galaxy with a stellar mass of M* = 4 x1010 M. [4] It contains an active galactic nucleus with double-peaked narrow lines. [5] [6] Moreover, it is also a Seyfert 2 galaxy. [7]
PGC 29820 is classified a jellyfish galaxy. [8] [9] [10] According to Gullieuszik, the galaxy is currently in a first phrase of infalling into the cluster where it is subjected to ram pressure by the intracluster medium. [2]
Because dense gas is compressed, it eventually collapses to form new stars in both the galaxy's tail and its disk. [4] According to researchers, the stars inside the tail, has a star formation rate of 0.22 M○ yr1 [11] which began during the last 500 million years. [2]
In additional, PGC 29820 shows a large presence of molecular gas making up H2 mass of 8.3 x 109 M○. Looking at ratio of total molecular hydrogen mass and stellar mass, it is estimated as 0.42. [12]
NGC 4395 is a nearby low surface brightness spiral galaxy located about 14 million light-years from Earth in the constellation Canes Venatici. The nucleus of NGC 4395 is active and the galaxy is classified as a Seyfert Type I known for its very low-mass supermassive black hole.
Ram pressure is a pressure exerted on a body moving through a fluid medium, caused by relative bulk motion of the fluid rather than random thermal motion. It causes a drag force to be exerted on the body. Ram pressure is given in tensor form as
In astronomy, the intracluster medium (ICM) is the superheated plasma that permeates a galaxy cluster. The gas consists mainly of ionized hydrogen and helium and accounts for most of the baryonic material in galaxy clusters. The ICM is heated to temperatures on the order of 10 to 100 megakelvins, emitting strong X-ray radiation.
The Sérsic profile is a mathematical function that describes how the intensity of a galaxy varies with distance from its center. It is a generalization of de Vaucouleurs' law. José Luis Sérsic first published his law in 1963.
The thick disk is one of the structural components of about 2/3 of all disk galaxies, including the Milky Way. It was discovered first in external edge-on galaxies. Soon after, it was proposed as a distinct galactic structure in the Milky Way, different from the thin disk and the halo in the 1983 article by Gilmore & Reid. It is supposed to dominate the stellar number density between 1 and 5 kiloparsecs above the galactic plane and, in the solar neighborhood, is composed almost exclusively of older stars. Its stellar chemistry and stellar kinematics are also said to set it apart from the thin disk. Compared to the thin disk, thick disk stars typically have significantly lower levels of metals—that is, the abundance of elements other than hydrogen and helium.
NGC 1270 is an elliptical galaxy located about 250 million light-years away in the constellation Perseus. It was discovered by astronomer Heinrich d'Arrest on February 14, 1863. NGC 1270 is a member of the Perseus Cluster and has an estimated age of about 11 billion years. However, Greene et al. puts the age of NGC 1270 at about 15.0 ± 0.50 Gy.
NGC 708 is an elliptical galaxy located 240 million light-years away in the constellation Andromeda and was discovered by astronomer William Herschel on September 21, 1786. It is classified as a cD galaxy and is the brightest member of Abell 262. NGC 708 is a weak FR I radio galaxy and is also classified as a type 2 Seyfert galaxy.
NGC 4074 is a peculiar lenticular galaxy located 310 million light-years away in the constellation Coma Berenices. It was discovered by astronomer William Herschel on April 27, 1785 and is a member of the NGC 4065 Group.
In astronomy, quenching is the process in which star formation shuts down in a galaxy. A galaxy that has been quenched is called a quiescent galaxy. Several possible astrophysical mechanisms have been proposed that could lead to quenching, which either result in a lack of cold molecular gas, or a decrease in how efficiently stars can form from molecular gas.
IC 4141 is a spiral galaxy in the constellation of Coma Berenices. The galaxy is located 900 million light-years away from Earth. Discovered in 1904 by German astronomer Max Wolf, it measures 255,000 light-years across in diameter. With a radial velocity of 19,000 kilometers per second, it is slowly drifting from the Solar System.
PGC 65543, is a spiral galaxy, with extensive star forming regions, located in Indus. It is 650 million light-years away from the Solar System and approximately measuring 90,000 light-years in diameter. The tidal interactions from certain galaxies which PGC 65543 is moving towards to, have caused it to get distorted. Its star-forming gas and dust are dynamically stripped by ram-pressure and formed into tendrils that stretch outwards, thus gives an appearance of a jellyfish galaxy.
PGC 1228197 known as WINGS J211347.41+022834.9 and JO206, is a large spiral galaxy located 700 million light-years away towards the constellation of Aquarius. The galaxy is estimated to be at least 160,000 light-years in diameter, making it somehow bigger than the Milky Way. With a radial velocity of 15,226 kilometers per second, it is slowly drifting away.
IC 64 is a massive lenticular galaxy located 622 million light-years away in the Pisces constellation. IC 64 has a diameter of 300,000 light-years, making it, three times bigger than the Milky Way and one of the largest galaxies observed. IC 64 was discovered by French astronomer Stephane Javelle on 5 December 1893. It has an active galactic nucleus, and is an emission line galaxy.
PGC 2456 known as KAZ 364 and JO201, is a spiral galaxy located in the constellation of Cetus. It is located 617 million light-years away from the Solar System. A member of Abell 85, PGC 2456 lies 360 kiloparsecs from the brightest cluster galaxy, Holmberg 15A.
IC 5337 or JW100, is a spiral galaxy located 800 million light-years away from the Solar System in the constellation of Pegasus.
PKS 0529-549 known as MRC 0529-549 and PKS B0529-549, is a radio galaxy located in the constellation Pictor. At the redshift of 2.57, the object is located nearly 10.8 billion light-years away from Earth.
2MASX J17201001+2637317 also known as PGC 1782937, is a massive type-cD elliptical galaxy located in the constellation of Hercules. With redshift of 0.16, the galaxy is located 2.4 billion light-years from Earth and the brightest cluster galaxy in the galaxy cluster, RX J1720.1+2638.
Abell 68 is massive and rich galaxy cluster located in the constellation of Pisces with a projected co-moving distance of approximately 1124.6 Mpc or 3.668 billion light-years away from Earth. The cluster is especially notable for its gravitational lensing and was first discovered by George O. Abell in 1958.
PG 1543+489, also known as QSO B1544+4855 and PGC 2325245, is a quasar located in the constellation of Boötes. At the redshift of 0.399, the object is located 4.5 billion light-years away from Earth. It was first discovered in 1983, by researchers who presented 114 objects in the Palomar-Green bright quasar survey, as one of the best studied samples of active galactic nuclei (AGN).