3C 254
{{Short description|Quasar in the constellation Ursa Major}}
{{Use dmy dates|date=March 2025}}
{{Infobox galaxy|name=3C 254|epoch=J2000.0|constellation name=Ursa Major|ra={{RA|11|14|38.7241}}|dec={{DEC|+40|37|20.285}}|z=0.735926|h_radial_v=220,625 km/s|dist_ly=6.318 Gly|appmag_v=17.42|appmag_b=17.62|type=RL1|names=4C 40.18, DA 298, LEDA 2817631, NRAO 369, QSO J1114+4037, 2E 2426|image=File:3C 254 SDSS image.jpg|caption=The quasar 3C 254. Above the object is the galaxy, 2MASS J11143975+4037350.}}
3C 254 is a radio-loud quasar{{Cite journal |last1=Megn |first1=A. V. |last2=Braude |first2=S. Ya. |last3=Rashkovskij |first3=S. L. |last4=Sharykin |first4=N. K. |last5=Shepelev |first5=V. A. |last6=Inyutin |first6=G. A. |last7=Khristenko |first7=A. D. |last8=Brazhenko |first8=A. I. |last9=Bulatsen |first9=V. G. |date=1996-01-01 |title=Interferometer observations of the quasar 3C 254 in the decameter wavelengths range. |url=https://ui.adsabs.harvard.edu/abs/1996KFNT...12f...3M/abstract |journal=Kinematika I Fizika Nebesnykh Tel |volume=12 |issue=6 |pages=3–12 |bibcode=1996KFNT...12f...3M |issn=0233-7665}} located in the constellation of Ursa Major. The object has a redshift of (z) 0.734 and is classified as a Fanaroff-Riley class type II source.{{Cite journal |last1=Donahue |first1=Megan |last2=Daly |first2=Ruth A. |last3=Horner |first3=Donald J. |date=2003-02-20 |title=Constraints on the Cluster Environments and Hot Spot Magnetic Field Strengths of the Radio Sources 3C 280 and 3C 254 |url=https://iopscience.iop.org/article/10.1086/345831/fulltext/ |journal=The Astrophysical Journal |volume=584 |issue=2 |pages=643–656 |doi=10.1086/345831 |arxiv=astro-ph/0211145 |bibcode=2003ApJ...584..643D |issn=0004-637X}} It was first identified by astronomers as an astronomical radio source in 1965.{{Cite journal |last=Schmidt |first=Maarten |date=April 1965 |title=Large Redshifts of Five Quasi-Stellar Sources. |url=https://adsabs.harvard.edu/full/1965ApJ...141.1295S |journal=The Astrophysical Journal |volume=141 |pages=1295 |doi=10.1086/148217 |bibcode=1965ApJ...141.1295S |issn=0004-637X}}
Description
3C 254 contains an asymmetrical radio structure consisting of two radio lobes and a central component.{{Cite journal |last1=Davis |first1=R. J. |last2=Stannard |first2=D. |last3=Conway |first3=R. G. |date=1983-12-01 |title=Interferometric observations of compact components in extragalactic radio sources - II |journal=Monthly Notices of the Royal Astronomical Society |volume=205 |issue=4 |pages=1267–1278 |doi=10.1093/mnras/205.4.1267 |doi-access=free |bibcode=1983MNRAS.205.1267D |issn=0035-8711}}{{Cite journal |last1=Thomasson |first1=P. |last2=Saikia |first2=D. J. |last3=Muxlow |first3=T. W. B. |date=2006-11-11 |title=3C 254: MERLIN observations of a highly asymmetric quasar |journal=Monthly Notices of the Royal Astronomical Society |volume=372 |issue=4 |pages=1607–1613 |doi=10.1111/j.1365-2966.2006.10955.x |doi-access=free |arxiv=astro-ph/0608481 |bibcode=2006MNRAS.372.1607T |issn=0035-8711}} Its radio spectrum is found straight and steep.{{Cite journal |last1=Hooimeyer |first1=J. R. A. |last2=Barthel |first2=P. D. |last3=Schilizzi |first3=R. T. |last4=Miley |first4=G. K. |date=1992-07-01 |title=The radio structure of extended quasars. I. A VLBI survey of the nuclear emission. |url=https://articles.adsabs.harvard.edu/pdf/1992A%26A...261...18H |journal=Astronomy and Astrophysics |volume=261 |pages=18–24 |bibcode=1992A&A...261...18H |issn=0004-6361}} When imaged by MERLIN (Multi-Element Radio-linked Interferometer Network) at 1539 MHz, the western lobe is made up of two hotspots, a compact primary hotspot and a more diffused secondary hotspot with an approximate peak brightness of 36 mJy. In addition, the western lobe is found to be significantly polarized compared to the eastern lobe, whose emission is less compact and stretching in a south-east direction. A study published in 1982 showed both lobes of 3C 254 are extended.{{Cite journal |last1=Schilizzi |first1=R. T. |last2=Kapahi |first2=V. K. |last3=Neff |first3=S. G. |date=1982-06-01 |title=VLA Observations of Hot Spots in High Luminosity Radio Sources |url=https://articles.adsabs.harvard.edu/pdf/1982JApA....3..173S |journal=Journal of Astrophysics and Astronomy |volume=3 |issue=2 |pages=173–187 |doi=10.1007/BF02714801 |bibcode=1982JApA....3..173S |issn=0250-6335}} There is also an eastern component found perpendicular towards the axis of the source, interpreted as a side-flow.{{Cite journal |last1=Liu |first1=R. |last2=Pooley |first2=G. |last3=Riley |first3=J. M. |date=1992-08-15 |title=Spectral ageing in a sample of 14 high-luminosity double radio sources |journal=Monthly Notices of the Royal Astronomical Society |volume=257 |issue=4 |pages=545–571 |doi=10.1093/mnras/257.4.545 |doi-access=free |bibcode=1992MNRAS.257..545L |issn=0035-8711}}
The host galaxy of 3C 354 according to imaging by Hubble Space Telescope (HST), has a complex morphology. It is orientated in an east-west direction, showing traces of emission plumes along the position angles of 285° and 45°.{{Cite journal |last1=Lehnert |first1=Matthew D. |last2=Miley |first2=George K. |last3=Sparks |first3=William B. |last4=Baum |first4=Stefi A. |last5=Biretta |first5=John |last6=Golombek |first6=Daniel |last7=de Koff |first7=Sigrid |last8=Macchetto |first8=Ferdinando D. |last9=McCarthy |first9=Patrick J. |date=August 1999 |title=HUBBLE SPACE TELESCOPE Snapshot Survey of 3CR Quasars: The Data |url=https://iopscience.iop.org/article/10.1086/313239/fulltext/36504.text.html |journal=The Astrophysical Journal Supplement Series |volume=123 |issue=2 |pages=351–376 |doi=10.1086/313239 |bibcode=1999ApJS..123..351L |issn=0067-0049|url-access=subscription }} Further evidence also showed the object is surrounded by a number of faint objects, suggesting it might belong in a galaxy cluster.{{Cite journal |last=Bremer |first=M. N. |date=1997-01-01 |title=3C 254: the alignment effect and unification schemes |url=https://articles.adsabs.harvard.edu/pdf/1997MNRAS.284..126B |journal=Monthly Notices of the Royal Astronomical Society |volume=284 |pages=126–136 |doi=10.1093/mnras/284.1.126 |doi-access=free |issn=0035-8711|hdl=1887/6700 |hdl-access=free }}
An extended emission-line region has been discovered around 3C 254. Based on observations, the region is extended by 80 kiloparsecs (kpc).{{Cite journal |last1=Forbes |first1=D. A. |last2=Crawford |first2=C. S. |last3=Fabian |first3=A. C. |last4=Johnstone |first4=R. M. |date=1990-06-01 |title=Extended emission-line gas around the quasars 3C 254 and 3C 309.1 . Very massive cooling flows. |url=https://ui.adsabs.harvard.edu/abs/1990MNRAS.244..680F/abstract |journal=Monthly Notices of the Royal Astronomical Society |volume=244 |pages=680 |bibcode=1990MNRAS.244..680F |issn=0035-8711}}{{Cite journal |last1=Crawford |first1=C. S. |last2=Vanderriest |first2=C. |date=1997-03-01 |title=Integral field spectroscopy of a jet-cloud interaction in the quasar 3C254 |journal=Monthly Notices of the Royal Astronomical Society |volume=285 |issue=3 |pages=580–592 |doi=10.1093/mnras/285.3.580 |doi-access=free |bibcode=1997MNRAS.285..580C |issn=0035-8711}} Further evidence also showed there are signs of kinematics and intensity in its emission lines, hinting the jet is interacting with a gas cloud. A secondary X-ray emission source was discovered although an optical counterpart wasn't found.{{Cite journal |last1=Crawford |first1=C. S. |last2=Lehmann |first2=I. |last3=Fabian |first3=A. C. |last4=Bremer |first4=M. N. |last5=Hasinger |first5=G. |date=1999-10-01 |title=Detection of X-ray emission from the host clusters of 3CR quasars |journal=Monthly Notices of the Royal Astronomical Society |volume=308 |issue=4 |pages=1159–1172 |doi=10.1046/j.1365-8711.1999.02804.x |doi-access=free |arxiv=astro-ph/9904371 |bibcode=1999MNRAS.308.1159C |issn=0035-8711}}
References
External links
- [https://simbad.u-strasbg.fr/simbad/sim-id?bibyear1=1850&bibyear2=%24currentYear&submit=Display&Ident=%401780843&Name=3C+254&bibdisplay=refsum&bibyear1=1850&bibyear2=%24currentYear#lab_bib 3C 254 by SIMBAD]
- [https://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Obj_id&objid=62403&objname=1&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1 3C 254 by NASA/IPAC Database]
{{Ursa Major}}