NGC 4848
Galaxy in the constellation Coma Berenices
From Wikipedia, the free encyclopedia
NGC 4848 is a barred spiral galaxy in the constellation Coma Berenices. It is about 340 million light-years from Earth, which, given its apparent dimensions, means that NGC 4848 is about 170,000 light years across. It was discovered by Heinrich d'Arrest on April 21, 1865.[3] It is considered part of the Coma Cluster, which is in its northwest part. The galaxy has been stripped of its gas as it passed through the cluster.[4]
| NGC 4848 | |
|---|---|
 NGC 4848 imaged by the Hubble Space Telescope | |
| Observation data (J2000 epoch) | |
| Constellation | Coma Berenices |
| Right ascension | 12h 58m 05.6s[1] |
| Declination | +28° 14′ 34″[1] |
| Redshift | 0.023513 ± 0.000033 |
| Heliocentric radial velocity | 7,049 ± 10 km/s[1] |
| Distance | 340 ± 15 Mly (104 ± 4.5 Mpc)[1] |
| Group or cluster | Coma Cluster |
| Apparent magnitude (V) | 13.7[2] |
| Characteristics | |
| Type | SBab: sp[1] |
| Apparent size (V) | 1.6′ × 0.5′[1] |
| Notable features | Hydrogen tail |
| Other designations | |
| UGC 8082, MCG +05-31-039, CGCG 160-055, PGC 44405, 5C 04.058[1] | |
Characteristics
NGC 4848 is a spiral galaxy viewed nearly edge-on that is classified as SBab by de Vaucouleurs. Its nucleus is active, and it has been categorised as an HII region.[5] A number of bright HII regions form a ring around the nucleus with a radius of 5–10 arcseconds. The star formation rate is estimated to be 9 M☉ per year based on the H-alpha, ultraviolet, infrared and radio luminosity.[4]
The galaxy distribution of hydrogen gas is asymmetrical and forms a tail pointing away from the cluster center. The tail has projected dimensions of 62.5 by 18.5 kpc and an estimated hydrogen mass of 4×109 M☉. The tail was probably formed as a result of ram pressure as the galaxy passed through the Coma Cluster and its intergalactic medium at a speed of about 1,330 km/s, starting 200 million years ago according to Fossati et al.,[4] while a previous study indicated a timeline of 400 million years.[6] The lost hydrogen is estimated to comprise two thirds of the original hydrogen content of the galaxy.[6] A few star-forming regions, probably HII regions, are in the tail.[4]
A dwarf galaxy may cross the disk of NGC 4848; however, its mass is too low to be a source of the hydrogen tail.[6]
See also
- NGC 4921, a spiral galaxy in the Coma Cluster that has lost its hydrogen
