KMS of Xinjiang Astronomical Observatory, CAS
ALMA imaging of the cold molecular and dusty disk in the type 2 active nucleus of the Circinus galaxy | |
Tristram, Konrad R. W.1; Impellizzeri, C. M. Violette2; Zhang, Zhi-Yu3,4; Villard, Eric5; Henkel, Christian6,7,8![]() | |
2022-08-18 | |
Source Publication | ASTRONOMY & ASTROPHYSICS
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ISSN | 0004-6361 |
Volume | 664Pages:A142 |
Contribution Rank | 8 |
Abstract | Context. The central engines of many active galactic nuclei (AGNs) are thought to be surrounded by warm molecular and dusty material in an axisymmetric geometry, thus explaining part of the observational diversity of active nuclei. Aims. We aim to shed light on the physical properties and kinematics of the molecular material in the nucleus of one of the closest type 2 active galaxies. Methods. To this end, we obtained high angular resolution Atacama Large Millimeter /submillimeter Array (ALMA) observations of the nucleus of the Circinus galaxy. The observations map the emission at 350 GHz and 690 GHz with spatial resolutions of similar to 3:8 pc and similar to 2:2 pc, respectively. Results. The continuum emission traces cold (T. 100K) dust in a circumnuclear disk with spiral arms on scales of 25 pc, plus a marginally resolved nuclear emission peak. The latter is not extended in polar direction as claimed based on earlier ALMA observations. A significant amount (of the order of 40%) of the 350 GHz emission is not related to dust, but most likely free-free emission instead. We detect CO(3 2) and CO(6 5) as well as HCO+(4 3), HCN(4 3), and CS(4 3). The CO emission is extended, showing a spiral pattern, similar to the extended dust emission. Towards the nucleus, CO is excited to higher transitions and its emission is self-absorbed, leading to an apparent hole in the CO(3 2) but not the CO(6 5) emission. On the other hand, the high gas density tracers HCO+, HCN, and CS show a strong, yet unresolved (.4 pc) concentration of the emission at the nucleus, pointing at a very small `torus'. The kinematics are dominated by rotation and point at a geometrically thin disk down to the resolution limit of our observations. In contrast to several other AGNs, no HCN enhancement is found towards the nucleus. Conclusions. The Circinus nucleus is therefore composed of at least two distinct components: (1) an optically thin, warm outflow of ionised gas containing clouds of dust which are responsible for the polar mid-infrared emission, but not seen at submillimetre wavelengths; and (2) a cold molecular and dusty disk, traced by submillimetre continuum and line emission. The latter is responsible for the bulk of the obscuration of the nucleus. These findings support the most recent radiative transfer calculations of the obscuring structures in AGNs, which find a similar two-component structure. |
Keyword | galaxies active galaxies nuclei galaxies Seyfert galaxies structure galaxies individual Circinus techniques high angular resolution |
DOI | 10.1051/0004-6361/202243535 |
Indexed By | SCI |
Language | 英语 |
WOS Keyword | SUBARCSECOND MIDINFRARED VIEW ; GALACTIC NUCLEUS ; OBSCURING TORI ; POLAR DUST ; DENSE GAS ; OUTFLOW ; EMISSION ; PARSEC ; MODEL ; WINDS |
Funding Project | NSFC[12041305] ; NSFC[12173016] ; Program for Innovative Talents, Entrepreneur in Jiangsu, China ; China Manned Space Project[CMS-CSST2021-A08] ; European Research Council (ERC)[833460] |
WOS Research Area | Astronomy & Astrophysics |
WOS Subject | Astronomy & Astrophysics |
WOS ID | WOS:000841821100008 |
Publisher | EDP SCIENCES S A |
Funding Organization | NSFC ; Program for Innovative Talents, Entrepreneur in Jiangsu, China ; China Manned Space Project ; European Research Council (ERC) |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.xao.ac.cn/handle/45760611-7/4864 |
Collection | 中国科学院新疆天文台 射电天文研究室_恒星形成与演化研究团组 |
Corresponding Author | Tristram, Konrad R. W. |
Affiliation | 1.European Southern Observ, Alonso Cordova 3107, Santiago, Chile 2.Leiden Univ, Leiden Observ, Pob 9513, NL-2300 RA Leiden, Netherlands 3.Nanjing Univ, Sch Astron & Space Sci, Nanjing 210093, Peoples R China 4.Nanjing Univ, Minist Educ, Lab Modern Astron & Astrophys, Nanjing 210093, Peoples R China 5.European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany 6.Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany 7.King Abdulaziz Univ, Fac Sci, Dept Astron, POB 80203, Jeddah 21589, Saudi Arabia 8.Chinese Acad Sci, Xinjiang Astron Observ, Urumqi 830011, Peoples R China 9.Sorbonne Univ, PSL Univ, CNRS, Observ Paris,LERMA,Coll France, F-75014 Paris, France 10.OAN IGN, Observatorio Madrid, Alfonso XII 3, Madrid 28014, Spain 11.Joint ALMA Observ, Alonso Cordova 3107, Santiago, Chile 12.Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany |
Recommended Citation GB/T 7714 | Tristram, Konrad R. W.,Impellizzeri, C. M. Violette,Zhang, Zhi-Yu,et al. ALMA imaging of the cold molecular and dusty disk in the type 2 active nucleus of the Circinus galaxy[J]. ASTRONOMY & ASTROPHYSICS,2022,664:A142. |
APA | Tristram, Konrad R. W..,Impellizzeri, C. M. Violette.,Zhang, Zhi-Yu.,Villard, Eric.,Henkel, Christian.,...&van der Werf, Paul P..(2022).ALMA imaging of the cold molecular and dusty disk in the type 2 active nucleus of the Circinus galaxy.ASTRONOMY & ASTROPHYSICS,664,A142. |
MLA | Tristram, Konrad R. W.,et al."ALMA imaging of the cold molecular and dusty disk in the type 2 active nucleus of the Circinus galaxy".ASTRONOMY & ASTROPHYSICS 664(2022):A142. |
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