IC 860
{{Short description|Galaxy in the constellation of Coma Berenices}}
{{Infobox galaxy|name=IC 860|image=File:IC860 - SDSS DR14.jpg|caption=SDSS image of IC 860|epoch=J2000|constellation name=Coma Berenices|ra={{RA|13|15|03.50}}|dec={{DEC|+24|37|07.79}}|z=0.012909|h_radial_v=3,870 km/s|dist_ly=155 Mly (47.52 Mpc)|appmag_v=0.044|appmag_b=0.057|type=Sa, HII;LIRG|size=35,000 ly|size_v=0.5' x 0.3'|names=CGCG 130-023, IRAS 13126+2452, ECO 03976, MCG +04-31-015, PGC 46086|notes=luminous infrared galaxy}}
IC 860 is a barred spiral galaxy in the constellation of Coma Berenices. It is located 155 million light years away from Earth.{{Cite web |title=Your NED Search Results |url=https://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Obj_id&objid=33643&objname=1&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1 |access-date=21 September 2024 |website=ned.ipac.caltech.edu}} It was discovered on June 16, 1892, by Stephan Javelle, a French astronomer.{{Cite web |title=Index Catalog Objects: IC 850 - 899 |url=https://cseligman.com/text/atlas/ic8a.htm#ic860 |access-date=21 September 2024 |website=cseligman.com}} It is a peculiar galaxy.{{Cite journal |last1=Kazes |first1=I. |last2=Karoji |first2=H. |last3=Sofue |first3=Y. |last4=Nakai |first4=N. |last5=Handa |first5=T. |date=1988-05-01 |title=A most peculiar galaxy : IC 860. |url=https://ui.adsabs.harvard.edu/abs/1988A&A...197L..22K/abstract |journal=Astronomy and Astrophysics |volume=197 |pages=L22–L24 |bibcode=1988A&A...197L..22K |issn=0004-6361}}
IC 860 is classified a nearby post-starburst galaxy, in early stages of transforming into its quiescent state.{{Cite journal |last1=Luo |first1=Yuanze |last2=Rowlands |first2=Kate |last3=Alatalo |first3=Katherine |last4=Sazonova |first4=Elizaveta |last5=Abdurro'uf |last6=Heckman |first6=Timothy |last7=Medling |first7=Anne M. |last8=Deustua |first8=Susana E. |last9=Nyland |first9=Kristina |last10=Lanz |first10=Lauranne |last11=Petric |first11=Andreea O. |last12=Otter |first12=Justin A. |last13=Aalto |first13=Susanne |last14=Dimassimo |first14=Sabrina |last15=French |first15=K. Decker |date=2022-10-01 |title=A Multiwavelength View of IC 860: What Is in Action inside Quenching Galaxies |journal=The Astrophysical Journal |volume=938 |issue=1 |pages=63 |doi=10.3847/1538-4357/ac8b7d |doi-access=free |arxiv=2208.08379 |bibcode=2022ApJ...938...63L |issn=0004-637X}} It is also vibrationally excited HCN luminous infrared galaxy (LIRG) with LHCN -VIB/LIR of 3.2 x 10−8. It has a dust obscured nucleus making it hard to determine whether it is a starburst galaxy or an active galactic nucleus (AGN).{{Cite journal |last1=Gorski |first1=M. D. |last2=Aalto |first2=S. |last3=König |first3=S. |last4=Wethers |first4=C. |last5=Yang |first5=C. |last6=Muller |first6=S. |last7=Viti |first7=S. |last8=Black |first8=J. H. |last9=Onishi |first9=K. |last10=Sato |first10=M. |date=February 2023 |title=The opaque heart of the galaxy IC 860: Analogous protostellar, kinematics, morphology, and chemistry |url=http://dx.doi.org/10.1051/0004-6361/202245166 |journal=Astronomy & Astrophysics |volume=670 |pages=A70 |doi=10.1051/0004-6361/202245166 |arxiv=2210.04499 |bibcode=2023A&A...670A..70G |issn=0004-6361}} In additional, the galaxy contains HI and OH absorption towards its central region. The galaxy has an implied mass of MSMBH of 4 x 107 MΘ based on its velocity rotation of vrot = 226 km s−1. The Eddington luminosity of IC 860 is 2 x 1012 LΘ.{{Cite journal |last1=Aalto |first1=S. |last2=Muller |first2=S. |last3=König |first3=S. |last4=Falstad |first4=N. |last5=Mangum |first5=J. |last6=Sakamoto |first6=K. |last7=Privon |first7=G. C. |last8=Gallagher |first8=J. |last9=Combes |first9=F. |last10=García-Burillo |first10=S. |last11=Martín |first11=S. |last12=Viti |first12=S. |last13=van der Werf |first13=P. |last14=Evans |first14=A. S. |last15=Black |first15=J. H. |date=July 2019 |title=The hidden heart of the luminous infrared galaxy IC 860 |url=http://dx.doi.org/10.1051/0004-6361/201935480 |journal=Astronomy & Astrophysics |volume=627 |pages=A147 |doi=10.1051/0004-6361/201935480 |issn=0004-6361|arxiv=1905.07275 }}
According to low [C II] 157.7 μm-to-LFIR ratios and by a mid-infrared silicate absorption, the findings suggest IC 860 does have a warm compact region. The region of the galaxy, is in a current phase of rapid evolution where inflows are accumulating column densities of interstellar dust and gas, sufficient to fuel its star formation or its AGN.
IC 860 was also observed in optical imaging. From the results, the galaxy has a massive V-shaped kiloparsec dust structure. As the nuclear gas only has an outflow velocity of vout = 170 – 200 km s−1, this makes it impossible to escape from the galaxy unless being accelerated.
In another study, IC 860 contains 4.83 GHz formaldehyde emission with a peak flux density of 2.0-2.2 mJy based from observations made by Arecibo Observatory. It is found to have three unique emission compartments centered between 3830 and 3990 km s−1.{{Cite journal |last1=Baan |first1=Willem A. |last2=An |first2=Tao |last3=Klöckner |first3=Hans-Rainer |last4=Thomasson |first4=Peter |date=2017-04-17 |title=The emission structure of formaldehyde megamasers |journal=Monthly Notices of the Royal Astronomical Society |volume=469 |issue=1 |pages=916–929 |doi=10.1093/mnras/stx895 |doi-access=free |issn=0035-8711|arxiv=1704.07337 }}