View source for Astronomy:NGC 2207 and IC 2163

{{short description|Pair of colliding spiral galaxies in the constellation Canis Major}}
{{Infobox Galaxy
| name = [[Astronomy:New General Catalogue|NGC]] 2207 / [[Astronomy:New General Catalogue#Index Catalogue|IC]] 2163
| image = NGC2207+IC2163.jpg
| image_size = 300px
|caption = [[Astronomy:Hubble Space Telescope|Hubble Space Telescope]] image of NGC 2207 (left) and IC 2163 (right)
| epoch = [[Astronomy:J2000|J2000]]
| type = SAB(rs)bc pec / SB(rs)c pec<ref name="ned">{{cite web
  | title=NASA/IPAC Extragalactic Database
  | work=Results for NGC 2207 / IC 2163
  | url=http://nedwww.ipac.caltech.edu/
  | access-date=2006-11-25 }}</ref>
| ra = {{RA|06|16|22.0}} / {{RA|06|16|28.0}}<ref name="ned" />
| dec = {{DEC|-21|22|22}} / {{DEC|-21|22|33}}<ref name="ned" />
| dist_ly = 81 ± 39 M[[Astronomy:Light-year|ly]]<br/>{{nowrap|(24.9 ± 12 M[[Astronomy:Parsec|pc]])}}<ref name=ned-dist>{{cite web
  |title=Distance Results for NGC 2207
  |work=NASA/IPAC Extragalactic Database
  |url=http://nedwww.ipac.caltech.edu/cgi-bin/nDistance?name=NGC+2207
  |access-date=2010-05-22}}</ref>
| z = 2741 ± 15 / 2765 ± 20 km/[[Second|s]]<ref name="ned" />
| appmag_v = 12.2 / 11.6<ref name="ned" />
| size_v = 4.3{{prime}} × 2.8{{prime}} / 3.0{{prime}} × 1.2{{prime}}<ref name="ned" />
| constellation name = [[Astronomy:Canis Major|Canis Major]]
| notes = colliding galaxies
| names = RR132a / RR132b,<ref name=ned /> [[Astronomy:Principal Galaxies Catalogue|PGC]] 018749 / 018751, [[Astronomy:Uppsala General Catalogue Addendum|UGCA]] 124/125<ref name="ned" />
}}
__NOTOC__
'''NGC 2207 and IC 2163''' are a pair of colliding spiral galaxies about 80 million [[Astronomy:Light-year|light-year]]s away<ref name=ned-dist/> in the [[Astronomy:Constellation|constellation]] [[Astronomy:Canis Major|Canis Major]]. Both galaxies were discovered by [[Biography:John Herschel|John Herschel]] in 1835.

The larger spiral, NGC 2207, is classified as an [[Astronomy:Intermediate spiral galaxy|intermediate spiral galaxy]] exhibiting a weak inner ring structure around the central bar. The smaller companion spiral, IC 2163, is classified as a [[Astronomy:Barred spiral galaxy|barred spiral galaxy]] that also exhibits a weak inner ring and an elongated spiral arm that is likely being stretched by [[Physics:Tidal force|tidal force]]s with the larger companion. Both galaxies contain a vast amount of dust and gas, and are beginning to exhibit enhanced rates of [[Astronomy:Star formation|star formation]], as seen in infrared images.

NGC 2207 is in the process of colliding and merging with IC 2163. But unlike the Antennae or the [[Astronomy:Mice Galaxies|Mice Galaxies]], they are still two separate spiral galaxies. They are only in the first step of colliding and merging, with NGC 2207 being in the process of [[Astronomy:Tidal stripping|tidally stripping]] IC 2163. Soon they will collide, probably looking a bit more like the [[Astronomy:Mice Galaxies|Mice Galaxies]]. In about a billion years time they are expected to merge and become an [[Astronomy:Elliptical galaxy|elliptical galaxy]] or perhaps a disk galaxy.<ref name="Ueda2014">{{cite journal
    | author=Junko Ueda |display-authors=0
    | title=Cold molecular gas in merger remnants. I. Formation of molecular gas disks
    | journal=The Astrophysical Journal Supplement Series 
    | volume=214
    | issue=1
    | pages=1
    | bibcode= 2014ApJS..214....1U
    | doi=10.1088/0067-0049/214/1/1|arxiv = 1407.6873 |year=2014
    |s2cid=716993
 }}</ref>

Four [[Astronomy:Supernova|supernova]]e have been observed in NGC 2207:
* type Ia '''SN 1975a''' in January 1975<ref>{{cite journal|author=Kirshner, Robert P. |author2=Arp, H.C. |author3=Dunlap, J.R.|date=1976|title=Observations of Supernovae - 1975a in NGC 2207 and 1975b in the Perseus Cluster|journal=Astrophysical Journal|volume=207|issue=1|pages=44–52 |bibcode = 1976ApJ...207...44K |doi = 10.1086/154465 |doi-access=free}}</ref> 
* type Ib [[Astronomy:SN 1999ec|SN 1999ec]] in October 1999<ref>{{cite journal|author=Jha, S. |display-authors=4  |author2=Garnavich, P. |author3=Challis, P. |author4=Kirshner, R. |author5=Berlind, P.|date=1999|title=Supernova 1999ec in NGC 2207|journal=IAU Circular|volume=7269|page=2|bibcode=1999IAUC.7269....2J}}</ref>
* type Ib [[Astronomy:SN 2003H|SN 2003H]]—discovered halfway between the two galaxies<ref name="pasp115">{{cite journal | author=van den Bergh, Sidney | author2=Li, Weidong | author3=Filippenko, Alexei V.  | title=Classifications of the Host Galaxies of Supernovae, Set II | journal=The Publications of the Astronomical Society of the Pacific | volume=115 | issue=813 | pages=1280&ndash;88 |date= 2003 | doi=10.1086/379106 | bibcode=2003PASP..115.1280V |arxiv = astro-ph/0308195 | s2cid=2015979 }}</ref>
* type II supernova '''SN 2013ai''' in March 2013<ref>{{cite journal|author=Conseil, E. |display-authors=4  |author2=Fraser, M. |author3=Inserra, C. |author4=Walton, N. |author5=Blagorodnova, N. |author6=Nicholl, M. |author7=Benetti, S. |author8=Pastorello, A. |author9=Valenti, S. |author10=Taubenberger, S. |author11=Smartt, S.J. |author12=Smith, K. |author13=Young, D. |author14=Sullivan, M. |author15=Gal-Yam, A. |author16=Yaron, O.|date=2013|title=Supernova 2013ai in NGC 2207 = Psn J06161835-2122329|journal=Central Bureau Electronic Telegrams|volume=3431  |issue=3431|page=1|bibcode=2013CBET.3431....1K}}</ref>

Two [[Astronomy:Supernova|supernova]]e have been observed in IC 2163:<ref name="Bishop-2018lab">[https://www.rochesterastronomy.org/sn2018/index.html#2018lab 2018lab] in IC 2136 (David Bishop)</ref>
* type II SN 2018lab
* unknown type SN SPIRITS17lb

==See also==
*[[Astronomy:Andromeda–Milky Way collision|Andromeda–Milky Way collision]]
*[[Astronomy:Antennae Galaxies|Antennae Galaxies]]
*[[Astronomy:Arp 299|Arp 299]]
*[[Astronomy:NGC 5090 and NGC 5091|NGC 5090 and NGC 5091]]
*NGC 6872 and IC 4970

==References==
{{reflist}}

==External links==
*[http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/41 HST: A grazing encounter between two spiral galaxies]
*{{cite simbad|title=NGC 2207}}
*{{cite simbad|title=IC 2163}}
*{{APOD|title=Spiral Galaxies in Collision|date=19 January 2014}}
{{Stars of Canis Major}}

{{DEFAULTSORT:NGC 2207 and IC 2163}}
[[Category:Intermediate spiral galaxies]]
[[Category:Barred spiral galaxies]]
[[Category:Peculiar galaxies]]
[[Category:Interacting galaxies]]
[[Category:Canis Major]]
[[Category:NGC objects|2207]]
[[Category:IC objects]]
[[Category:Principal Galaxies Catalogue objects|18749]]
[[Category:UGCA objects]]

{{Sourceattribution|NGC 2207 and IC 2163}}