IC 485
{{Short description|Spiral galaxy in the constellation Gemini}}
{{Infobox galaxy|name=IC 485|image=File:IC485 - SDSS DR14.jpg|caption=IC 485 captured by SDSS|epoch=J2000|constellation name=Gemini|ra={{RA|08|00|19.75}}|dec={{DEC|+26|42|04.99}}|z=0.027827|h_radial_v=8,342 km/s|dist_ly=375 Mly (114.97 Mpc)|appmag_v=0.13|appmag_b=0.17|type=Sa, AGN|size=135,000 ly|size_v=1.35' x 0.32'|names=UGC 4156, PGC 22443, IRAS 07572+2650}}
IC 485 is a spiral galaxy located in the constellation of Gemini, located 375 million light years from Earth. It was discovered by the Austrian astronomer, Rudolf Spitaler on March 6, 1891.{{Cite web |title=Index Catalog Objects: IC 450 - 499 |url=https://cseligman.com/text/atlas/ic4a.htm#ic485 |access-date=2024-09-20 |website=cseligman.com}} It has an estimated diameter of 1.35' x 0.32' arcmin, meaning the galaxy is about 135,000 light years across.{{Cite web |title=Your NED Search Results |url=https://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=IC+485&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES |access-date=2024-09-20 |website=ned.ipac.caltech.edu}}
IC 485 is a candidate disc-maser galaxy.{{Cite journal |last1=Ladu |first1=Elisabetta |last2=Tarchi |first2=Andrea |last3=Castangia |first3=Paola |last4=Surcis |first4=Gabriele |last5=Braatz |first5=James A. |last6=Panessa |first6=Francesca |last7=Pesce |first7=Dominic |date=2024-01-01 |title=IC 485 : A candidate for a new disk-maser galaxy |journal=Cosmic Masers: Proper Motion Toward the Next-Generation Large Projects |url=https://ui.adsabs.harvard.edu/abs/2024IAUS..380...45L/abstract |volume=380 |pages=45–49 |doi=10.1017/S174392132300248X|bibcode=2024IAUS..380...45L |doi-access=free }} It has a projected distance of 122.0 ± 8.5 megaparsecs.{{Cite journal |last1=Kamali |first1=F. |last2=Henkel |first2=C. |last3=Brunthaler |first3=A. |last4=Impellizzeri |first4=C. M. V. |last5=Menten |first5=K. M. |last6=Braatz |first6=J. A. |last7=Greene |first7=J. E. |last8=Reid |first8=M. J. |last9=Condon |first9=J. J. |last10=Lo |first10=K. Y. |last11=Kuo |first11=C. Y. |last12=Litzinger |first12=E. |last13=Kadler |first13=M. |date=September 2017 |title=Radio continuum of galaxies with H2O megamaser disks: 33 GHz VLA data |url=http://dx.doi.org/10.1051/0004-6361/201730899 |journal=Astronomy & Astrophysics |volume=605 |pages=A84 |doi=10.1051/0004-6361/201730899 |issn=0004-6361|arxiv=1706.02699 |bibcode=2017A&A...605A..84K }}{{Cite web |title=IC 485: a LINER galaxy with an elusive accretion disc! {{!}} EVLBI |url=https://www.evlbi.org/evn-newsletter/may-2024/IC485-liner-galaxy |access-date=2024-09-20 |website=www.evlbi.org}} The morphology classification of the galaxy is Sa, and it has a low luminous active galactic nucleus (AGN) of LX ~ 5 x 1042 erg s−1. The AGN activity of IC 485 has been debated. It is either classified a LINER{{Cite journal |last1=Liu |first1=Xin |last2=Shen |first2=Yue |last3=Strauss |first3=Michael A. |last4=Hao |first4=Lei |date=2011-08-01 |title=Active Galactic Nucleus Pairs from the Sloan Digital Sky Survey. I. The Frequency on ~5-100 kpc Scales |url=https://ui.adsabs.harvard.edu/abs/2011ApJ...737..101L/abstract |journal=The Astrophysical Journal |volume=737 |issue=2 |pages=101 |doi=10.1088/0004-637X/737/2/101 |arxiv=1104.0950 |bibcode=2011ApJ...737..101L |issn=0004-637X}} or a Seyfert type II galaxy. But its high X-ray luminosity seems to confirm the latter.{{Cite journal |last1=Ladu |first1=E. |last2=Tarchi |first2=A. |last3=Castangia |first3=P. |last4=Surcis |first4=G. |last5=Braatz |first5=J. A. |last6=Panessa |first6=F. |last7=Pesce |first7=D. W. |date=2024-02-01 |title=IC 485: A new candidate disc-maser galaxy at ∼100 Mpc - Milliarcsecond resolution study of the galaxy nucleus and the H2O megamaser |url=https://www.aanda.org/articles/aa/full_html/2024/02/aa47795-23/aa47795-23.html#S2 |journal=Astronomy & Astrophysics |language=en |volume=682 |pages=A25 |doi=10.1051/0004-6361/202347795 |issn=0004-6361|arxiv=2310.08998 }}
Using the Karl G. Jansky Very Large Array observations, a team of astronomers led by Jeremy Darling discovered a H2O maser containing a broad multi-component. The maser of IC 485 has a peak flux of 80 mJy with an isotopic luminosity of Liso = (868 ± 46)LΘ.{{Cite journal |last=Darling |first=Jeremy |date=March 2017 |title=How to Detect Inclined Water Maser Disks (and Possibly Measure Black Hole Masses) |journal=The Astrophysical Journal |language=en |volume=837 |issue=2 |pages=100 |doi=10.3847/1538-4357/aa6114 |doi-access=free |issn=0004-637X|arxiv=1702.06545 |bibcode=2017ApJ...837..100D }} According to Darling, he was also able to find a faint unresolved radio source with its angular resolution measured as 90 milliarcseconds ≈ 50 parsecs.
In 2022, the galaxy was further studied by another team of astronomers. They discovered, it has two other 22 GHz H2O maser modules with a velocity separation of 472 km s−1. One is located in the central nuclear region while the other is at a redshifted velocity. Based on estimations on its connection with an edge-on disc, IC 485 has a mass of MBH ~ 1.2 x 107 MΘ. According to estimation of its black hole, the galaxy has a core luminosity of 1 x 1036 - 5 x 1037 erg s−1.