IC 1481
| IC 1481 | |
|---|---|
 IC 1481 captured by SDSS | |
| Observation data (J2000 epoch) | |
| Constellation | Pisces |
| Right ascension | 23h 19m 25.12s |
| Declination | +05° 54′ 22.24″ |
| Redshift | 0.020331 |
| Heliocentric radial velocity | 6,095 km/s |
| Distance | 289 Mly (88.60 Mpc) |
| Apparent magnitude (V) | 0.25 |
| Apparent magnitude (B) | 0.33 |
| Characteristics | |
| Type | Sb, LINER |
| Size | 65,000 ly |
| Apparent size (V) | 0.8' x 0.7' |
| Other designations | |
| UGC 12505, PGC 71070, IRAS 23168+0537 | |
IC 1481 is a spiral galaxy located in the Pisces constellation. It is located 289 million light years from Earth[1] and was discovered by Austrian astronomer, Rudolf Spitaler on October 6, 1891.[2] The galaxy has an approximate diameter of 65,000 light years with a surface brightness of 12.8 square arcmin.[3]
According to an optical image, IC 1481 has an Sb morphological classification.[4] The galaxy also contains an active galactic nucleus (AGN). It is classfied as a LINER galaxy.[5][6] showing an extensive narrow-line region. The region of IC 1481 has bright portions forming in a figure eight pattern and extends at Position Angle (PA) = 50° by ~ 13 arcseconds on both sides of its nucleus. It also show emission knots towards the field edges.[7] The stellar population of IC 1481 shows a post-starburst signature, which the Balmer lines contain strong absorption.[8]
A luminous H2O maser emission is found towards IC 1481. The spectrum of the maser has a narrow and strong feature of 0.15 Jy and FWHM = 2 km s-1. It is also weak and broad. With a isotropic luminosity of L = 320 LΘ, this suggests a megamaser.[4]
The maser features are found distributed, which they contain a velocity gradient. This suggests the AGN of IC 1481 has an unstable molecular 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 a rotation of Vrot = 124-168 km s-1 and a velocity 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's black hole mass of <107 MΘ, its mass is higher.[4][9]
References
[edit]- ^ "Your NED Search Results". ned.ipac.caltech.edu. Retrieved 2024-09-24.
- ^ "Index Catalog Objects: IC 1450 - 1499". cseligman.com. Retrieved 2024-09-24.
- ^ "Revised IC Data for IC 1481". spider.seds.org. Retrieved 2024-09-24.
- ^ a b c d Mamyoda, Koichi; Nakai, Naomasa; Yamauchi, Aya; Diamond, Philip; HurÉ, Jean-Marc (2009-10-25). "Detection of a Sub-Keplerian Water Maser Disk at the Active Galactic Nucleus of the Galaxy IC 1481". Publications of the Astronomical Society of Japan. 61 (5): 1143–1151. doi:10.1093/pasj/61.5.1143. ISSN 2053-051X.
- ^ Bennert, N.; Schulz, H.; Henkel, C. (2004-05-01). "Spectral characteristics of water megamaser galaxies. II. ESO 103-G035, TXS 2226-184, and IC 1481". Astronomy and Astrophysics. 419: 127–137. arXiv:astro-ph/0403247. Bibcode:2004A&A...419..127B. doi:10.1051/0004-6361:20034497. ISSN 0004-6361.
- ^ Huchra, J.P.; Wyatt, W.F.; Davis, M. (1982). "New Seyfert Bright Galaxies". The Astronomical Journal. 87: 1628. Bibcode:1982AJ.....87.1628H. doi:10.1086/113254. Retrieved 2024-09-24.
- ^ Thomas, Adam D.; Dopita, Michael A.; Shastri, Prajval; Davies, Rebecca; Hampton, Elise; Kewley, Lisa; Banfield, Julie; Groves, Brent; James, Bethan L.; Jin, Chichuan; Juneau, Stéphanie; Kharb, Preeti; Sairam, Lalitha; Scharwächter, Julia; Shalima, P. (2017-09-01). "Probing the Physics of Narrow-line Regions in Active Galaxies. IV. Full Data Release of the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7)". The Astrophysical Journal Supplement Series. 232 (1): 11. doi:10.3847/1538-4365/aa855a. ISSN 0067-0049.
- ^ C Keel, William; Moiseev, Alexei; Kozlova, DV (2022). "The TELPERION survey for distant [O iii] clouds around luminous and hibernating AGN". Oxford Academic. 510 (3): 4608–4625. doi:10.1093/mnras/stab3656.
- ^ Huré, J.-M.; Hersant, F.; Surville, C.; Nakai, N.; Jacq, T. (2011-06-01). "AGN disks and black holes on the weighting scales". Astronomy & Astrophysics. 530: A145. doi:10.1051/0004-6361/201015062. ISSN 0004-6361.
