编辑“︁NGC 2273”︁（章节）

==特征 ==
[[File:NGC 2273 GALEX WikiSky.jpg|thumb|left|[[星系演化探测器]]拍摄的NGC 2273]]
NGC 2273有一个[[環星系]]，倾角为41 度，有由两个[[螺旋星系|螺旋臂]]构成一个内环和两个外伪环，并有一个直径40弧秒的星系棒。<ref>{{cite journal |last1=Aguerri |first1=J. A. L. |last2=Beckman |first2=J. E. |last3=Prieto |first3=M. |title=Bar Strengths, Bar Lengths, and Corotation Radii, Derived Photometrically for 10 Barred Galaxies |url=https://archive.org/details/sim_astronomical-journal_1998-11_116_5/page/2136 |journal=The Astronomical Journal |date=November 1998 |volume=116 |issue=5 |pages=2136–2153 |doi=10.1086/300615|bibcode=1998AJ....116.2136A |doi-access=free }}</ref>
该星系拥有质量约{{val|1.1|e=9|ul=M_solar}}的[[21公分線|氢气]]（HI），大部分位于外伪环区域。该星系还拥有大量的分子气体，如CO线所示，这说明[[恒星形成]]活动在该星系很活跃。<ref name="Driel91">{{cite journal |last1=van Driel |first1=W. |last2=Buta |first2=R. J. |title=A study of the ringed galaxies NGC2273, 4826, and 6217. I - H I line observations |url=https://archive.org/details/sim_astronomy-and-astrophysics_1991-05_245_1/page/n30 |journal=Astronomy and Astrophysics |date=1 May 1991 |volume=245 |pages=7–26 |issn=0004-6361 |bibcode=1991A&A...245....7V}}</ref>星系的总红外光度为10<sup>10.25</sup> [[太阳亮度|''L<sub>☉</sub>'']]。<ref>{{cite journal |last1=Sanders |first1=D. B. |last2=Mazzarella |first2=J. M. |last3=Kim |first3=D.-C. |last4=Surace |first4=J. A. |last5=Soifer |first5=B. T. |title=The IRAS Revised Bright Galaxy Sample |url=https://archive.org/details/sim_astronomical-journal_2003-10_126_4/page/1607 |journal=The Astronomical Journal |date=October 2003 |volume=126 |issue=4 |pages=1607–1664 |doi=10.1086/376841|arxiv=astro-ph/0306263 |bibcode=2003AJ....126.1607S |s2cid=14825701 }}</ref>

[[哈勃空间望远镜]]对星系中心附近20弧秒区域的观测显示星系的螺旋臂与星系内环相对应。星系中心的卵状结构由一个星系棒和两个弧形的星系核环组成，它所造成的辐射与[[电离氢区]]有关。<ref name="Ferruit00">{{cite journal |last1=Ferruit |first1=Pierre |last2=Wilson |first2=Andrew S. |last3=Mulchaey |first3=John |title=Hubble Space Telescope WFPC2 Imaging of a Sample of Early-Type Seyfert Galaxies |journal=The Astrophysical Journal Supplement Series |date=May 2000 |volume=128 |issue=1 |pages=139–169 |doi=10.1086/313379 |bibcode=2000ApJS..128..139F|doi-access=free }}</ref>核周围有一个直径7弧秒的环状结构，其西北部分比较清晰，离星系核20弧秒处有另一个星环。<ref>{{cite journal |last1=Yankulova |first1=I. M. |title=The circumnuclear gas and dust environment of the ringed Seyfert 2 galaxy MKN 620 |journal=Astronomy and Astrophysics |date=1 April 1999 |volume=344 |pages=36–42 |issn=0004-6361 |bibcode=1999A&A...344...36Y}}</ref>

===星系核===
根据其[[光學頻譜]]中存在的[[譜線]]，NGC 2273具有[[活动星系核]] ，并被分类为II型[[西佛星系]]。<ref>{{cite journal |last1=Huchra |first1=J. P. |last2=Wyatt |first2=W. F. |last3=Davis |first3=M. |title=New bright Seyfert Galaxies |journal=The Astronomical Journal |date=December 1982 |volume=87 |pages=1628 |doi=10.1086/113254|bibcode=1982AJ.....87.1628H }}</ref><ref>{{cite journal |last1=Ho |first1=Luis C. |last2=Filippenko |first2=Alexei V. |last3=Sargent |first3=Wallace L. W. |title=A Search for "Dwarf'' Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies |journal=The Astrophysical Journal Supplement Series |date=October 1997 |volume=112 |issue=2 |pages=315–390 |doi=10.1086/313041|arxiv=astro-ph/9704107 |bibcode=1997ApJS..112..315H |s2cid=17086638 }}</ref>此外，在星系中心还检测到了水{{tsl|en|kilomaser|千脉泽}}。这可以由[[活动星系核]]或明显的[[恒星]]形成活动而产生。<ref>{{cite journal |last1=Zhang |first1=J. S. |last2=Henkel |first2=C. |last3=Kadler |first3=M. |last4=Greenhill |first4=L. J. |last5=Nagar |first5=N. |last6=Wilson |first6=A. S. |last7=Braatz |first7=J. A. |title=Extragalactic H2O masers and X-ray absorbing column densities |journal=Astronomy & Astrophysics |date=19 April 2006 |volume=450 |issue=3 |pages=933–944 |doi=10.1051/0004-6361:20054138|doi-access=free |bibcode=2006A&A...450..933Z }}</ref>

[[BeppoSAX卫星]]、[[XMM-牛顿卫星]]和[[钱德拉X射线天文台]]猜测NGC 2273核心被[[柱密度]]较高的康普顿粗柱（Compton thick column）遮住，<ref>{{cite journal |last1=Maiolino |first1=R. |last2=Salvati |first2=M. |last3=Bassani |first3=L. |last4=Dadina |first4=M. |last5=della Ceca |first5=R. |last6=Matt |first6=G. |last7=Risaliti |first7=G. |last8=Zamorani |first8=G. |title=Heavy obscuration in X-ray weak AGNs |journal=Astronomy and Astrophysics |date=1 October 1998 |volume=338 |pages=781–794 |issn=0004-6361 |bibcode=1998A&A...338..781M|arxiv=astro-ph/9806055 }}</ref><ref>{{cite journal |last1=Guainazzi |first1=M. |last2=Fabian |first2=A. C. |last3=Iwasawa |first3=K. |last4=Matt |first4=G. |last5=Fiore |first5=F. |title=On the transmission-dominated to reprocessing-dominated spectral state transitions in Seyfert 2 galaxies |journal=Monthly Notices of the Royal Astronomical Society |date=1 January 2005 |volume=356 |issue=1 |pages=295–308 |doi=10.1111/j.1365-2966.2004.08448.x|arxiv=astro-ph/0409689 |bibcode=2005MNRAS.356..295G |doi-access=free }}</ref>{{tsl|en|Advanced Satellite for Cosmology and Astrophysics||ASCA}}估计其有{{val|1.1|e=24}} cm<sup>−2</sup><ref name=Terashima02/>，[[朱雀卫星]]估计其有{{val|1.5|e=24}} cm<sup>−2</sup>。<ref name="Awaki09">{{cite journal |last1=Awaki |first1=Hisamitsu |last2=Terashima |first2=Yuichi |last3=Higaki |first3=Yuusuke |last4=Fukazawa |first4=Yasushi |title=Detection of Hard X-Rays from the Compton-Thick Seyfert 2 Galaxy NGC 2273 with Suzaku |journal=Publications of the Astronomical Society of Japan |date=30 January 2009 |volume=61 |issue=sp1 |pages=S317–S325 |doi=10.1093/pasj/61.sp1.S317|arxiv=0810.4570 |bibcode=2009PASJ...61S.317A |s2cid=12846803 }}</ref>Fe-K线表明，[[硬X射线]]尝试通过冷金属物质时被反射。<ref name=Terashima02>{{cite journal |last1=Terashima |first1=Yuichi |last2=Iyomoto |first2=Naoko |last3=Ho |first3=Luis C. |last4=Ptak |first4=Andrew F. |title=X-Ray Properties of LINERs and Low-Luminosity Seyfert Galaxies Observed with ASCA. I. Observations and Results |journal=The Astrophysical Journal Supplement Series |date=March 2002 |volume=139 |issue=1 |pages=1–36 |doi=10.1086/324373|arxiv=astro-ph/0203005 |doi-access=free |bibcode=2002ApJS..139....1T }}</ref>星系核心区域的光谱有微弱的[[偏振]]，尤其是[[H-α]]线。<ref>{{cite journal |last1=Moran |first1=Edward C. |last2=Barth |first2=Aaron J. |last3=Kay |first3=Laura E. |last4=Filippenko |first4=Alexei V. |title=The Frequency of Polarized Broad Emission Lines in Type 2 Seyfert Galaxies |journal=The Astrophysical Journal |date=10 September 2000 |volume=540 |issue=2 |pages=L73–L77 |doi=10.1086/312876|arxiv=astro-ph/0007357 |bibcode=2000ApJ...540L..73M |doi-access=free }}</ref>从NGC 2273发现的宽X射线光谱由热的疏散的软的部分、反射部分和能量集中部分组成。该星系2-10 keV的X射线通量估计为{{val|1.7|e=42}} ergs<sup>−1</sup>.<ref name="Awaki09"/>

该星系核有两个相距170[[秒差距]]的[[相对论性喷流]]无线电波源发射线性[[无线电波]]。<ref>{{cite journal |last1=Ulvestad |first1=J. S. |last2=Wilson |first2=A. S. |title=Radio structures of Seyfert galaxies. VI - VLA observations of a nearby sample |url=https://archive.org/details/sim_astrophysical-journal_1984-10-15_285_2/page/438 |journal=The Astrophysical Journal |date=October 1984 |volume=285 |pages=439 |doi=10.1086/162520|bibcode=1984ApJ...285..439U }}</ref>在 [O III] λ5007的图像中可以看到线型喷发物喷出的物质在核周围已经扩展到2弧秒大小。它与无线电波发射源对齐，可能与星系核有关。<ref name="Ferruit00"/>

关于活动星系核活动所需的能量来源，最广为接受的猜想是星系中心[[超大质量黑洞]]的周围存在一个[[吸积盘]]。基于水脉泽环核圆盘的运动，该星系中心黑洞质量约是{{val|7.5|0.4|e=6}} {{solar mass}}。该吸积盘还出现扭曲。<ref>{{cite journal |last1=Kuo |first1=C. Y. |last2=Braatz |first2=J. A. |last3=Condon |first3=J. J. |last4=Impellizzeri |first4=C. M. V. |last5=Lo |first5=K. Y. |last6=Zaw |first6=I. |last7=Schenker |first7=M. |last8=Henkel |first8=C. |last9=Reid |first9=M. J. |last10=Greene |first10=J. E. |title=The Megamaser Cosmology Project. III. Accurate Masses of Seven Supermassive Black Holes in Active Galaxies with Circumnuclear Megamaser Disks |journal=The Astrophysical Journal |date=20 January 2011 |volume=727 |issue=1 |pages=20 |doi=10.1088/0004-637X/727/1/20|arxiv=1008.2146 |doi-access=free |bibcode=2011ApJ...727...20K }}</ref>