| IC 1481 | |
|---|---|
 IC 1481 captured bySDSS | |
| Observation data (J2000epoch) | |
| Constellation | Pisces |
| Right ascension | 23h 19m 25.1234s |
| Declination | +05° 54′ 22.243″ |
| Redshift | 0.020331 |
| Heliocentric radial velocity | 6,095km/s |
| Distance | 289Mly (88.60Mpc) |
| Apparent magnitude (V) | 0.25 |
| Apparent magnitude (B) | 0.33 |
| Characteristics | |
| Type | Sb, LINER |
| Size | 65,000ly |
| Apparent size (V) | 0.8' x 0.7' |
| Other designations | |
| IRAS 23168+0537,UGC 12505,PGC 71070,CGCG 406-064 | |
IC 1481 is aspiral galaxy located in thePisces constellation. It is located 289 millionlight years fromEarth[1] and was discovered by Austrian astronomer,Rudolf Spitaler on October 6, 1891.[2] The galaxy has an approximatediameter of 65,000 light years with asurface brightness of 12.8 square arcmin.[3]
According to an optical image, IC 1481 has an Sbmorphological classification.[4] The galaxy also contains anactive galactic nucleus (AGN). It is classified as aLINER galaxy.[5][6] showing an extensivenarrow-line region. The region of IC 1481 has bright portions forming in a figure eight pattern and extends atPosition Angle (PA) = 50° by ~ 13 arcseconds on both sides of its nucleus. It also showemission knots towards the field edges.[7] Thestellar population of IC 1481 shows a post-starburst signature, which theBalmer lines contain strong absorption.[8]
A luminous H2O maser emission is found towards IC 1481. Thespectrum of the maser has a narrow and strong feature of 0.15 Jy andFWHM = 2 km s−1. It is also weak and broad. With an isotropicluminosity of L = 320 LΘ, this suggests amegamaser.[4]
The maser features are found distributed, which they contain avelocity gradient. This suggests the AGN of IC 1481 has an unstablemolecular gas disk with a mass of (4.3 ± 0.3) x 107 MΘ. The disk is seen edge-on. It has a thickness of 2H = 1.5-4.2 pc and a radius of r = 2.8-14.0 pc making the largest amongst other maser disks observed in other AGNs. Not to mention, the disk has arotation of Vrot = 124–168 km s−1 and avelocity dispersion measured by △V ≈ 31 km s−1. Further observations found the disk of IC 1481 is huge indicated by its rotation curve being a sub-Keplerian.[4] When compared to the galaxy'sblack hole mass of <107 MΘ, its mass is higher.[4][9]
Onesupernova has been observed in IC 1481: SN 2000ey (type Ia, mag. 16.2).[10][11]
