| MR 2251−178 | |
|---|---|
 | |
| Observation data(Epoch ) | |
| Constellation | Aquarius |
| Right ascension | 22h 51m 12.2s |
| Declination | −17° 51′ 49″ |
| Redshift | 0.064 z |
| Notable features | Largest emission line nebula surrounding it |
| See also:Quasar,List of quasars | |
MR 2251−178 is a relatively nearby radio-quietquasar located at a distance of z=0.064 in the constellationAquarius. It has the record of having the largest ionizednebula surrounding it with it having the mass of 6 million solar masses. Aspiral complex that extends for over 200 kiloparsecs also surrounds thequasar.[1][2]
The quasar is a small but gas-richspiral galaxy that has much of its gasionized from a recentgalactic merger event with a nearby galaxy calledG1. It is located on the outskirts of an irregularcluster of galaxies.[1] This cluster has approximately 50 galaxies within it.[3]
MR 2251−178 has the largestnebula surrounding it out of any knownquasar discovered. The bulk of it is composed ofhydrogen.[2] The nebula is ionized but a large fraction of the nebula is very faint and diffuse. The smooth rotation of the nebula eliminates a cooling flow of gas as the origin of this nebula. Instead it likely originated from a pastmerger event with a nearby galaxy namedG1.[2][1]
Thegalaxy had experienced a recent galactic merger with the galaxyG1. It is located nearby and the result of the merger that left ittidally stripped of gas. It also lead to the creation of the ionized nebula surrounding MR 2251−178.[1]
