UGC 1775
{{Short description|Galaxy in the constellation Cetus}}
{{Sky|02|18|26.3964|+|05|39|14.012}}
{{Infobox galaxy
| name = UGC 1775
| image = Arp10 - SDSS DR14.jpg
| caption = UGC 1775 imaged by the Sloan Digital Sky Survey
| epoch = J2000
| type = S? {{cite web
| website=NASA/IPAC Extragalactic Database
| title=Results for object UGC 01775
| url=https://ned.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=UGC+1775
| access-date=2024-03-26 }}
| dist_ly = 395 ± 28 Mly (121 ± 8.5 Mpc)
| size = ~{{convert|72.24|kpc|ly|abbr=on|lk=on|order=flip}} (estimated){{r|ned}}
| appmag_v = 13.8
| size_v = 1.5{{prime}} × 1.5{{prime}}
| constellation name = Cetus
| notes = Collisional ring
| names = {{odlist | CGCG= 413-069 | Arp= 10 | VV= 362 | MCG= +01-06-062 | IRAS= 02158+0525 | PGC= 8802}}
}}
UGC 1775 or Arp 10 is a ring galaxy in the constellation Cetus. The galaxy lies about 400 million light years away from Earth, which means, given its apparent dimensions, that UGC 1775 is approximately 220,000 light years across. The earliest known reference to this galaxy comes from part 3 of the Morphological Catalogue of Galaxies, published in 1963, where it is listed as MCG +01-06-062. The galaxy is included in Halton Arp's Atlas of Peculiar Galaxies in the galaxies with split arms category.{{cite book | last=Arp | first=Halton | title=Atlas of Peculiar Galaxies | publisher=California Institute of Technology | location=Pasadena, California | year=1966 | url=http://ned.ipac.caltech.edu/level5/Arp/frames.html | access-date=5 Jan 2010}} (online version, including Arp's original tabular data, and PDF link)
Characteristics
The galaxy features a bright ring with a faint bar. Its nucleus is off-centre and it is surrounded by a bright ring of HII regions where new stars are formed. One fainter outer ring or shell also hosts a faint arc of HII regions.{{cite journal |last1=Charmandaris |first1=V. |last2=Appleton |first2=P. N. |last3=Marston |first3=A. P. |title=Threshold star-formation effects in the peculiar galaxy ARP 10 (= VV 362) |journal=The Astrophysical Journal |date=September 1993 |volume=414 |pages=154 |doi=10.1086/173064|arxiv=astro-ph/9303008 }} The hydrogen emission of the galaxy shows a large disturbed hydrogen disk extending for 2.7 times the optical diameter of the galaxy and features shells.{{cite journal |last1=Charmandaris |first1=V. |last2=Appleton |first2=P. N. |title=The Neutral Hydrogen Disk of ARP 10 (=VV 362): A Nonequilibrium Disk Associated with a Galaxy with Rings and Ripples |journal=The Astrophysical Journal |date=April 1996 |volume=460 |pages=686 |doi=10.1086/177001|arxiv=astro-ph/9510003 }} The galaxy has a high star formation rate, which was estimated based on the H-alpha emission to be 5.4 {{solar mass|link=yes}} per year, while based on the infrared luminosity, it is 11.2 {{solar mass}} per year. The mid-infrared emission is associated with the nucleus and the star forming regions of the ring.{{cite journal |last1=Charmandaris |first1=V. |last2=Laurent |first2=O. |last3=Mirabel |first3=I.F. |last4=Gallais |first4=P. |last5=Sauvage |first5=M. |last6=Vigroux |first6=L. |last7=Cesarsky |first7=C. |title=The Mid-Infrared View of Star Formation in Collisional Ring Galaxies |journal=Astrophysics and Space Science |date=2001 |volume=276 |issue=2/4 |pages=553–559 |doi=10.1023/A:1017597211676}}
The ring is considered to have been created by another galaxy passing through the disk of the galaxy near its centre about 85 million years ago.{{cite journal |last1=Bizyaev |first1=D. V. |last2=Moiseev |first2=A. V. |last3=Vorobyov |first3=E. I. |title=Propagating Star Formation in the Collisional Ring Galaxy Arp 10 |journal=The Astrophysical Journal |date=10 June 2007 |volume=662 |issue=1 |pages=304–321 |doi=10.1086/516627|arxiv=astro-ph/0703600 }} As there are no similar mass galaxies visible in the vicinity of UGC 1775 it has been proposed that the non-linear kinematics of the gas in the galaxy are the result of the accretion of a smaller galaxy by a gas-rich spiral galaxy.{{cite journal |last1=Reshetnikov |first1=V. P. |title=Kinematic study of the ring galaxy ARP 10 |journal=Astrophysics |date=April 1998 |volume=41 |issue=2 |pages=106–111 |doi=10.1007/BF03035748}} However more detailed observations indicate that the smaller galaxy is visible as a knot next to the nucleus of the main galaxy. Another small galaxy lying along the minor axis of the galaxy is a background object.
The galaxy is seen nearly face-on, at an inclination of 22 degrees.
Supernova
One supernova has been observed in UGC 1775. SN 2000dx was a type Ia supernova discovered by the Lick Observatory Supernova Search (LOSS) on 30 October 2000 with an apparent magnitude of 17.3.{{cite web | website=Transient Name Server | title=SN{{nbsp}}2000dx | url=https://www.wis-tns.org/object/2000dx | publisher = IAU | access-date=9 April 2025}} The supernova was a few days before maximum brightness, located 7.9" east and 12.3" south of the nucleus of UGC 1775.{{cite journal |last1=Schwartz |first1=M. |last2=Li |first2=W. D. |last3=Filippenko |first3=A. V. |last4=Modjaz |first4=M. |last5=Treffers |first5=R. R. |title=Supernova 2000dx in UGC 1775 |journal=International Astronomical Union Circular |date=1 November 2000 |volume=7514 |pages=2 |url=http://www.cbat.eps.harvard.edu/iauc/07500/07514.html#Item2 |issn=0081-0304}}
References
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