{{Short description|Radio galaxy in the constellation Draco}} {{Infobox galaxy|name=WN B1851+5707|epoch=[[J2000.0]]|constellation name=[[Draco (constellation)|Draco]]|ra={{RA|18|52|08.56}}<ref name="ned" />|dec={{DEC|+57|11|42.50}}<ref name="ned" />|z=0.107035<ref name="ned" />|h_radial_v=32,088 ± 0 [[kilometer per second|km/s]]<ref name="ned" />|dist_ly={{convert|476.48 ± 33.35|Mpc|Mly|abbr=on|lk=on|order=flip}}<ref name="ned" />|type=USS<ref name="ned" />|mag_j=13.76<ref name="ned" />|size=~{{convert|73.3|kpc|ly|abbr=on|lk=on|order=flip}} (estimated){{r|ned}}|names=[[2MASX]] J18520859+5711430, [[Sixth Cambridge Survey of Radio Sources|6C]] B185115.2+570808, [[Lyon-Meudon Extragalactic Database|LEDA]] 2559680, [[Eighth Cambridge Survey|8C]] 1851+571, [[NRAO VLA Sky Survey|NVSS]] J185208+571142, [[ROSAT|RX]] J1852.1+5711:[HDH2012] BCG, WN B1851+5707:[MPM2011] a<ref name="ned" />|image=File:Image of WN B1851+5707.png|caption=[[Pan-STARRS]] image of WN B1851+5707}}
'''WN B1851+5707''' also known as '''WN B1851+5707a''', is a [[radio galaxy]] located in the constellation of [[Draco (constellation)|Draco]]. The [[redshift]] of the object is (z) 0.107<ref name="ned">{{Cite web |title=NED Search results for WN B1851+5707 |url=https://ned.ipac.caltech.edu/byname?objname=LEDA+2559680&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1 |access-date=2026-05-19 |website=NASA/IPAC Extragalactic Database}}</ref> and it was first discovered by [[Astronomer|astronomers]] in November 1998 from the WENSS survey where they classified it as an [[elliptical galaxy]] without the presence of any [[Spectral line|emission lines]] in its [[Visible spectrum|optical spectrum]].<ref>{{Cite journal |last1=de Ruiter |first1=H. R. |last2=Parma |first2=P. |last3=Stirpe |first3=G. M. |last4=Perez-Fournon |first4=I. |date=November 1998 |title=Bright galaxies from WENSS. I. The minisurvey |url=https://ui.adsabs.harvard.edu/scan/manifest/1998A%26A...339...34D?art=true |journal=Astronomy and Astrophysics |volume=339 |pages=34–40}}</ref>
== Description == WN B1851+5707 is categorized as a dying radio galaxy located at the center of a cool core [[galaxy cluster]], RX J1852.1+5711.<ref name=":0">{{Cite journal |last1=Murgia |first1=M. |last2=Markevitch |first2=M. |last3=Govoni |first3=F. |last4=Parma |first4=P. |last5=Fanti |first5=R. |last6=Ruiter |first6=H. R. de |last7=Mack |first7=K.-H. |date=2012-12-01 |title=Chandra observations of dying radio sources in galaxy clusters |url=https://www.aanda.org/articles/aa/abs/2012/12/aa19702-12/aa19702-12.html |journal=Astronomy & Astrophysics |language=en |volume=548 |pages=A75 |doi=10.1051/0004-6361/201219702 |issn=0004-6361|arxiv=1210.6864 }}</ref> Radio imaging made with the [[Very Large Array]] (VLA) found it is actually made up of two separate [[Astronomical radio source|radio sources]] called WN B1851+5707a and WN B1851+5707b, associated with this object and another dying radio galaxy.<ref name=":0" /><ref name=":1">{{Cite journal |last1=Murgia |first1=M. |last2=Parma |first2=P. |last3=Mack |first3=K.-H. |last4=Ruiter |first4=H. R. de |last5=Fanti |first5=R. |last6=Govoni |first6=F. |last7=Tarchi |first7=A. |last8=Giacintucci |first8=S. |last9=Markevitch |first9=M. |date=2011-02-01 |title=Dying radio galaxies in clusters |url=https://www.aanda.org/articles/aa/pdf/2011/02/aa15302-10.pdf |journal=Astronomy & Astrophysics |language=en |volume=526 |pages=A148 |doi=10.1051/0004-6361/201015302 |issn=0004-6361}}</ref> The main source (WN B1851+5707a) has an ultra steep [[radio spectrum]] with a compact and luminous appearance.<ref name=":1" /><ref>{{Cite journal |last1=De Breuck |first1=C. |last2=van Breugel |first2=W. |last3=Röttgering |first3=H. J.A. |last4=Miley |first4=G. |date=April 2000 |title=A sample of 669 ultra steep spectrum radio sources to find high redshift radio galaxies |journal=Astronomy and Astrophysics Supplement Series |volume=143 |issue=2 |pages=303–333 |doi=10.1051/aas:2000181 |arxiv=astro-ph/0002297 |issn=0365-0138}}</ref> The [[spectral index]] of the source is found to be 1.7α and the total flux [[density]] is 53.3 mJy at 1.4 [[Hertz|GHz]] [[Frequency|frequencies]]. A total radio power at 151 [[Hertz|MHz]] is calculated as 10<sup>25.3</sup> W Hz<sup>-1</sup>.<ref>{{Citation |last1=Murgia |first1=M. |title=Dying Radio Galaxies In Clusters |date=2004-05-26 |work=Conference proceeding: X-Ray and Radio Connections Santa Fe, New Mexico |id=arXiv:astro-ph/0405091 |last2=Parma |first2=P. |last3=Ruiter |first3=H. R. de |last4=Mack |first4=K.-H. |last5=Fanti |first5=R. |arxiv=astro-ph/0405091 }}</ref>
There is a point-like source positioned in the center of the galaxy with radio [[flux]] originating from within an extended structure, making it a de-energized source. It has a shapeless appearance and is asymmetric. The total linear [[size]] is estimated to be 30 × 15 [[Parsec|kiloparsecs]]. There are no signs of any [[Astrophysical jet|radio jets]] categorized as active.<ref name=":1" /> A study published in 2011, has found the [[Radio galaxy|radio lobes]] ejected from the galaxy have a total radio [[luminosity]] of 1.8 × 10<sup>25</sup> W/Hz and a spectra index of 0.7α. No evidence of [[X-ray astronomy|X-ray]] cavities were associated with the lobes.<ref name=":0" />
== References == <references />
== External links == {{WikiSky}}
{{Draco (constellation)}} [[Category:Radio galaxies]] [[Category:Draco (constellation)]] [[Category:Elliptical galaxies]] [[Category:LEDA objects|2559680]] [[Category:ROSAT objects]] [[Category:Astronomical objects discovered in 1998]]