NGC 612
{{Short description|Galaxy in the constellation Sculptor}}
{{Infobox galaxy
|constellation name=Sculptor
|dist_ly={{Val|388|e=6}} ly (119.33 ± 8.36 Mpc)
|epoch=J2000
|image=NGC 612.png
|caption=Hubble Space Telescope image of NGC 612
|name=NGC 612
|size_v=1.5 × 0.9 arcmin
|type=S0a{{cite journal|doi=10.1093/mnras/stad1119 |doi-access=free |title=WISDOM project – XIV. SMBH mass in the early-type galaxies NGC 0612, NGC 1574, and NGC 4261 from CO dynamical modelling |date=2023 |last1=Ruffa |first1=Ilaria |last2=Davis |first2=Timothy A. |last3=Cappellari |first3=Michele |last4=((Bureau)) |first4=Martin |last5=Elford |first5=Jacob |last6=Iguchi |first6=Satoru |last7=Lelli |first7=Federico |last8=Liang |first8=Fu-Heng |last9=Liu |first9=Lijie |last10=Lu |first10=Anan |last11=Sarzi |first11=Marc |last12=Williams |first12=Thomas G. |journal=Monthly Notices of the Royal Astronomical Society |volume=522 |issue=4 |pages=6170–6195 |arxiv=2304.06117 |bibcode=2023MNRAS.522.6170R }}
|size=~122.43 kpc (diameter)
|notes=Rare example of a non-elliptical radio galaxy
|names={{odlist|MCG= -06-04-046|PGC= 5827}}{{cite simbad|title=NGC 612|accessdate=2021-02-19}}
}}
NGC 612 is a lenticular galaxy in the constellation of Sculptor located approximately 388 million light-years from Earth. It is a type II Seyfert galaxy and thus has an active galactic nucleus.{{Cite web|url=http://ned.ipac.caltech.edu/?q=byname&out_csys=Equatorial&corr_z=1&omegav=0.73&extend=no&omegam=0.27&img_stamp=YES&out_equinox=J2000.0&objname=NGC%20612&list_limit=5&of=pre_text&hconst=73&obj_sort=RA%20or%20Longitude&keyword=objname|title=NGC 612 NASA/IPAC Extragalactic Database Results|website=ned.ipac.caltech.edu|access-date=2018-10-31}}{{Cite web|url=http://spider.seds.org/ngc/revngcic.cgi?NGC612|title=Revised NGC Data for NGC 612|website=spider.seds.org|access-date=2018-10-31}} NGC 612 has been identified as an extremely rare example of a non-elliptical radio galaxy, hosting one of the nearest powerful FR-II radio sources.{{Cite journal|last1=Véron-Cetty|first1=M. P.|last2=Véron|first2=P.|date=2001|title=Are all radio galaxies genuine ellipticals?|journal=Astronomy & Astrophysics|language=en|volume=375|issue=3|pages=791–796|doi=10.1051/0004-6361:20010902|issn=0004-6361|bibcode=2001A&A...375..791V|doi-access=free}}{{Sky|01|33|57.74|-|36|29|35.7}}{{Cite journal|last1=Emonts|first1=B. H. C.|last2=Morganti|first2=R.|author2-link=Raffaella Morganti|last3=Oosterloo|first3=T. A.|last4=Holt|first4=J.|last5=Tadhunter|first5=C. N.|last6=van der Hulst|first6=J. M.|last7=Ojha|first7=R.|last8=Sadler|first8=E. M.|date=2008|title=Enormous disc of cool gas surrounding the nearby powerful radio galaxy NGC 612 (PKS 0131−36)|journal=Monthly Notices of the Royal Astronomical Society|language=en|volume=387|issue=1|pages=197–208|doi=10.1111/j.1365-2966.2008.13142.x|doi-access=free |issn=0035-8711|arxiv=0805.3371|bibcode=2008MNRAS.387..197E |s2cid=7916786 }}
Observation history
The object was discovered by British astronomer John Herschel on 29 November, 1837.{{Cite web|url=http://cseligman.com/text/atlas/ngc6.htm#612|title=New General Catalog Objects: NGC 600–649|website=cseligman.com|language=en-US|access-date=2018-10-31}} John Louis Emil Dreyer, compiler of the first New General Catalogue of Nebulae and Clusters of Stars, described NGC 612 as "faint, very small, round, 12th magnitude star to the west."
Physical characteristics
File:NGC 612 in optical and radio wavelengths.png
NGC 612 has a fairly well-developed luminous disc seen almost edge-on and features a strong dust ring. The disk features an unusually young star population with ages in the range ~0.04–0.1 Gyr. The galaxy is surrounded by an enormous disc of cool neutral hydrogen gas with a mass of {{val|2.0|e=10}} M☉ distributed in a 140 kpc wide structure along the galactic disc and dust lane of NGC 612. The majority of the gas is relatively settled in regular rotation with a velocity of 850 km/s.
NGC 612 is one{{Cite journal |last1=Ekers |first1=R. D. |last2=Goss |first2=W. M. |last3=Kotanyi |first3=C. G. |last4=Skellern |first4=D. J. |date=1978-10-01 |title=NGC 612-A Radio Galaxy with a Disk |url=https://ui.adsabs.harvard.edu/abs/1978A&A....69L..21E |journal=Astronomy and Astrophysics |volume=69 |pages=L21 |bibcode=1978A&A....69L..21E |issn=0004-6361}} of 5 (as of 2020) known lenticular galaxies that show large-scale radio emissions. Both spiral galaxies and lenticular galaxies rarely host large scale radio emissions. It is not understood why these types of galaxies are so rare.{{Cite journal |last1=Duchesne |first1=S. W. |last2=Johnston-Hollitt |first2=M. |date=2019-04-01 |title=The remnant radio galaxy associated with NGC 1534 |url=https://ui.adsabs.harvard.edu/abs/2019PASA...36...16D |journal=Publications of the Astronomical Society of Australia |volume=36 |pages=e016 |doi=10.1017/pasa.2018.26 |issn=1323-3580|arxiv=1806.09255 |bibcode=2019PASA...36...16D }} The supermassive black hole (SMBH) at the center of NGC 612, which powers the radio emission, has a mass with a lower limit of {{val|3.2e9|u={{solar mass}}}}.
A faint bridge, spanning 400 kpc, exists between NGC 612 and the gas-rich barred spiral galaxy NGC 619, indicating that an interaction between both galaxies occurred at some point. Current or past interaction, such as a merger event, is currently the most likely trigger of NGC 612's radio source.
See also
- NGC 4151 – another example of a non-elliptical radio galaxy
- List of galaxies
References
{{reflist}}
{{NGC10}}{{Sculptor (constellation)}}
{{DEFAULTSORT:NGC 612}}
Category:Astronomical objects discovered in 1837
Category:Discoveries by John Herschel