{{Short description|Radio galaxy in the constellation Draco}} {{Infobox galaxy|name=[[Third Cambridge Catalogue of Radio Sources|3C]] 343.1|epoch=[[J2000.0]]|constellation name=[[Draco (constellation)|Draco]]|ra={{RA|16|38|28.22}}<ref name="ned" />|dec={{DEC|+62|34|44.31}}<ref name="ned" />|z=0.752380<ref name="ned" />|h_radial_v=225,558 [[kilometer per second|km/s]]<ref name="ned" />|dist_ly=6.777 [[light year|Gly]]|appmag_v=20.7|type=NLRG Sy2<ref name="ned" />|names=[[Lyon-Meudon Extragalactic Database|LEDA]] 2821600, [[Fourth Cambridge Survey|4C]] +62.27, [[NRAO VLA Sky Survey|NVSS]] J163828+623443, 87GB 163755.4+624035, [[Seventh Cambridge Survey|7C]] 1637+6240, [[Eighth Cambridge Survey|8C]] 1637+626, DA 419, NRAO 0511, CoNFIG 258, VIPS 1002, [[International Celestial Reference Frame|ICRF]] J163828.2+623444<ref name="ned" />|image=File:Image of 3C 343.1.png|caption=[[Sloan Digital Sky Survey|SDSS]] image of 3C 343.1}}

'''3C 343.1''' is a [[radio galaxy]] located in the constellation of [[Draco (constellation)|Draco]]. The [[redshift]] of the object is (z) 0.752<ref name="ned">{{Cite web |title=NED Search results for 3C 343.1 |url=https://ned.ipac.caltech.edu/byname?objname=3C+343.1&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1 |access-date=2025-09-28 |website=NASA/IPAC Extragalactic Database}}</ref> and it was first recorded in the [[Third Cambridge Catalogue of Radio Sources]] survey in 1966.<ref>{{Cite journal |last=Véron |first=P. |date=June 1966 |title=Optical Positions for Radio Sources in the 3c Revised Catalogue |url=https://doi.org/10.1086/148682 |journal=The Astrophysical Journal |volume=144 |pages=861 |doi=10.1086/148682 |bibcode=1966ApJ...144..861V |issn=0004-637X|url-access=subscription }}</ref> It is also a [[quasar]], pairing up with a foreground galaxy located at (z) 0.344,<ref>{{Cite journal |last1=Arp |first1=H. |last2=Burbidge |first2=E. M. |last3=Burbidge |first3=G. |date=2004-02-01 |title=The double radio source 3C 343.1: A galaxy-QSO pair with very different redshifts |url=https://www.aanda.org/articles/aa/abs/2004/06/aafj201/aafj201.html |journal=Astronomy & Astrophysics |language=en |volume=414 |issue=3 |pages=L37–L40 |doi=10.1051/0004-6361:20031745 |arxiv=astro-ph/0401007 |bibcode=2004A&A...414L..37A |issn=0004-6361}}</ref> and is classified as a compact steep [[spectrum]] source (CSS).<ref>{{Cite journal |last1=Hirst |first1=Paul |last2=Jackson |first2=Neal |last3=Rawlings |first3=Steve |date=December 2003 |title=Near-infrared spectroscopy of powerful compact steep-spectrum radio sources |journal=Monthly Notices of the Royal Astronomical Society |volume=346 |issue=3 |pages=1009–1020 |doi=10.1111/j.1365-2966.2003.07155.x |arxiv=astro-ph/0309055 |bibcode=2003MNRAS.346.1009H |doi-access=free |issn=0035-8711}}</ref><ref>{{Cite journal |last1=Privon |first1=G. C. |last2=O’Dea |first2=C. P. |last3=Baum |first3=S. A. |last4=Axon |first4=D. J. |last5=Kharb |first5=P. |last6=Buchanan |first6=C. L. |last7=Sparks |first7=W. |last8=Chiaberge |first8=M. |date=April 2008 |title=WFPC2 LRF Imaging of Emission-Line Nebulae in 3CR Radio Galaxies |journal=The Astrophysical Journal Supplement Series |language=en |volume=175 |issue=2 |pages=423–461 |doi=10.1086/525024 |arxiv=0710.3105 |bibcode=2008ApJS..175..423P |issn=0067-0049 }}</ref>

== Description == The host galaxy of 3C 343.1 has a blue appearance mainly due to the presence of an early-type [[stellar population]] or a recent wave of [[star formation]].<ref>{{Cite journal |last1=Spinrad |first1=H. |last2=Westphal |first2=J. |last3=Kristian |first3=J. |last4=Sandage |first4=A. |date=September 1977 |title=Spectroscopy and photometry of the distant radio galaxy 3C 343.1 |url=https://articles.adsabs.harvard.edu/pdf/1977ApJ...216L..87S |journal=The Astrophysical Journal |volume=216 |pages=L87 |doi=10.1086/182517 |bibcode=1977ApJ...216L..87S |issn=0004-637X}}</ref> The total star formation rate of the galaxy is estimated to be 1.7<sup>+0.5</sup><sub>-0.4</sub> × 10<sup>11</sup> M<sub>☉</sub>, with the host [[infrared]] [[luminosity]] estimated to be 2.9<sup>+0.6</sup><sub>-0.5</sub> × 10<sup>11</sup> [[Solar luminosity|L<sub>☉</sub>]]. It has a [[supermassive black hole]] mass of 28.7 × 10<sup>7</sup> M<sub>☉</sub>.<ref>{{Cite journal |last1=Westhues |first1=Christian |last2=Haas |first2=Martin |last3=Barthel |first3=Peter |last4=Wilkes |first4=Belinda J. |last5=Willner |first5=S. P |last6=Kuraszkiewicz |first6=Joanna |last7=Podigachoski |first7=Pece |last8=Leipski |first8=Christian |last9=Meisenheimer |first9=Klaus |last10=Siebenmorgen |first10=Ralf |last11=Chini |first11=Rolf |date=2016-04-20 |title=Star Formation in 3CR Radio Galaxies and Quasars at AT z &lt; 1* |journal=The Astronomical Journal |language=en |volume=151 |issue=5 |pages=120 |doi=10.3847/0004-6256/151/5/120 |arxiv=1602.07443 |bibcode=2016AJ....151..120W |doi-access=free |issn=0004-6256 }}</ref> The nucleus of the galaxy has been categorized as compact.<ref>{{Cite journal |last1=McCarthy |first1=Patrick J. |last2=Miley |first2=George K. |last3=de Koff |first3=Sigrid |last4=Baum |first4=Stefi A. |last5=Sparks |first5=William B. |last6=Golombek |first6=Daniel |last7=Biretta |first7=John |last8=Macchetto |first8=Ferdinando |date=October 1997 |title=''Hubble Space Telescope'' Snapshot Survey of 3CR Radio Source Counterparts. II. Radio Galaxies with z > 0.5 |url=https://iopscience.iop.org/article/10.1086/313035/pdf |journal=The Astrophysical Journal Supplement Series |volume=112 |issue=2 |pages=415–421 |doi=10.1086/313035 |bibcode=1997ApJS..112..415M |issn=0067-0049}}</ref>

3C 343.1 has a compact source. When observed with the [[Very Large Array]] (VLA), the source has an elongated appearance in the [[position angle]] of 110°, with two clearly resolved components observed on a 15 [[Hertz|GHz]] radio map.<ref>{{Cite journal |last1=Pearson |first1=T. J. |last2=Readhead |first2=A. C. S. |last3=Perley |first3=R. A. |date=May 1985 |title=Compact radio sources in the 3C catalog |url=https://articles.adsabs.harvard.edu/pdf/1985AJ.....90..738P |journal=The Astronomical Journal |volume=90 |pages=738 |doi=10.1086/113782 |bibcode=1985AJ.....90..738P |issn=0004-6256}}</ref> An 18 [[Centimetre|centimeter]] observation with [[Very-long-baseline interferometry|Very Long Baseline Interferometry]] (VLBI), showed the source is double with two asymmetrical components displaying high [[surface brightness]] profiles. The components also display a steep [[radio spectrum]] described as straight.<ref>{{Cite journal |last1=Fanti |first1=C. |last2=Fanti |first2=R. |last3=Parma |first3=P. |last4=Schilizzi |first4=R.T. |last5=van Breugel |first5=W.J.M. |date=February 1985 |title=Compact steep spectrum 3 CR radio sources. VLBI observations at 18 cm. |url=https://articles.adsabs.harvard.edu/pdf/1985A%26A...143..292F |journal=Astronomy and Astrophysics |language=en |volume=143 |page=292 |bibcode=1985A&A...143..292F |issn=0004-6361 |archive-url=https://web.archive.org/web/20240327105002/https://ui.adsabs.harvard.edu/abs/1985A&A...143..292F/abstract |archive-date=2024-03-27}}</ref> Newer VLBI observations made in 2021 at 327 GHz frequencies found the source displays asymmetric lobes that are separated by around 215 [[Minute and second of arc|milliarcseconds]]. No radio core has been discovered, although the components have a flat [[radio spectrum]] with observed steepening at 610 [[Hertz|MHz]].<ref>{{Cite journal |last1=Dallacasa |first1=D |last2=Orienti |first2=M |last3=Fanti |first3=C |last4=Fanti |first4=R |date=2021-04-13 |title=VLBI images at 327 MHz of compact steep spectrum and GHz-peaked spectrum sources from the 3C and PW samples |journal=Monthly Notices of the Royal Astronomical Society |volume=504 |issue=2 |pages=2312–2324 |doi=10.1093/mnras/stab1014 |doi-access=free |issn=0035-8711|arxiv=2104.12804 }}</ref> A [[Astrophysical jet|radio jet]] is present in the source, with a linear size of 1.57 kiloparsecs.<ref>{{Cite journal |last1=Kawakatu |first1=Nozomu |last2=Nagao |first2=Tohru |last3=Woo |first3=Jong-Hak |date=2009-03-10 |title=Exploring the Disk-Jet Connection From the Properties of Narrow-Line Regions in Power Young Radio-Loud Activie Galactic Nuclei |journal=The Astrophysical Journal |volume=693 |issue=2 |pages=1686–1695 |doi=10.1088/0004-637x/693/2/1686 |arxiv=0812.1329 |issn=0004-637X}}</ref>

An observation conducted in 1995, found 3C 343.1 has an [[Spectral line|emission-line]] nebula region. The [[Radio wave|radio emission]] of the region is extended along the direction of the source for more than five [[Minute and second of arc|arcseconds]]. making it possible that this could be classified as an [[extended emission-line region]].<ref>{{Cite journal |last1=McCarthy |first1=Patrick J. |last2=Spinrad |first2=Hyron |last3=van Breugel |first3=Wil |date=July 1995 |title=Emission-Line Imaging of 3CR Radio Galaxies. I. Imaging Data |url=https://articles.adsabs.harvard.edu/pdf/1995ApJS...99...27M |journal=The Astrophysical Journal Supplement Series |language=en |volume=99 |pages=27 |doi=10.1086/192178 |bibcode=1995ApJS...99...27M |issn=0067-0049 |archive-url=https://web.archive.org/web/20240216072934/https://ui.adsabs.harvard.edu/abs/1995ApJS...99...27M/abstract |archive-date=2024-02-16}}</ref> A linear feature is seen orientating along the east–west axis based on broad-band images.<ref>{{Cite journal |last1=Axon |first1=D. J. |last2=Capetti |first2=A. |last3=Fanti |first3=R. |last4=Morganti |first4=R. |last5=Robinson |first5=A. |last6=Spencer |first6=R. |date=November 2000 |title=The Morphology of the Emission-Line Region Of Compact Steep-Spectrum Radio Sources |journal=The Astronomical Journal |language=en |volume=120 |issue=5 |pages=2284–2299 |doi=10.1086/316838 |arxiv=astro-ph/0006355 |bibcode=2000AJ....120.2284A |issn=0004-6256 }}</ref> The nuclear spectrum of the galaxy has been found to show either the presence of weak [[ionization]] lines or none at all. Little signs of [[Polarization (waves)|polarization]] have also been detected in the galaxy.<ref>{{Cite journal |last1=Tran |first1=Hien D. |last2=Cohen |first2=Marshall H. |last3=Ogle |first3=Patrick M. |last4=Goodrich |first4=Robert W. |last5=di Serego Alighieri |first5=Sperello |date=1998-06-20 |title=Scattered Radiation from Obscured Quasars in Distant Radio Galaxies |url=https://iopscience.iop.org/article/10.1086/305752/fulltext/ |journal=The Astrophysical Journal |volume=500 |issue=2 |pages=660–672 |doi=10.1086/305752 |arxiv=astro-ph/9801063 |bibcode=1998ApJ...500..660T |issn=0004-637X}}</ref>

== References == <references />

== External links == *{{WikiSky}} *[http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ICRF%20J163828.2%2B623444 3C 343.1 on SIMBAD]

{{Draco (constellation)}} [[Category:Radio galaxies]] [[Category:3C objects|343.1]] [[Category:Draco (constellation)]] [[Category:Active galaxies]] [[Category:Seyfert galaxies]] [[Category:LEDA objects|2821600]] [[Category:4C objects|+62.27]] [[Category:Astronomical objects discovered in 1962]] [[Category:Quasars]]