我们给出了用SMA观测到的NGC 5128(半人马座A)中心1'(1 kpc)的12 CO(2-1)发射的高分辨率图像。我们首次阐明了该区域分子气体的分布和运动学,分辨率为6 '.0 × 2'.4(100 pc × 40 pc)。我们在空间上分辨了内部24“x 12”(400 pc x 200 pc)的环核分子气体,它沿着位置角P.A. = 155度,垂直于无线电/X射线射流。环核气体的SE和NW分量与在较大半径处发现的分子气体有关。这种气体在P.A.呈现为两条平行的细丝。= 120度,这是coextensive与3千秒差距的形状的长边先前观察到的尘埃连续,以及电离和纯旋转H2线。空间和运动学的不对称性是明显的,在环核和外部气体,这表明非共面和/或非圆形运动。我们扩展到内半径(r < 200 pc)以前研究的翘曲盘模型建立再现中央平行四边形结构。采用翘曲盘模型,我们将证实在半径r = 200 - 800 pc(12“-50”)之间的发射间隙,正如以前所建议的那样。虽然这个模型解释了这个突出的特征,但是,我们的12 CO(2-1)观测结果显示了与这个模型的相关偏差。也就是说,环核气体与较大半径处的气体之间的物理联系,平行四边形特征上较亮的东南和西北侧,以及其长边的外曲率。总的来说,它更接近S形形态,这一趋势也在其他分子物种中发现。因此,我们探索定性的弱双对称的潜力,自然会解释这些特点可能的贡献。
英文摘要:
We present high resolution images of the 12CO(2-1) emission in the central 1' (1 kpc) of NGC 5128 (Centaurus A), observed using the SMA. We elucidate for the first time the distribution and kinematics of the molecular gas in this region with a resolution of 6'.0 x 2'.4 (100 pc x 40 pc). We spatially resolve the circumnuclear molecular gas in the inner 24'' x 12'' (400 pc x 200 pc), which is elongated along a position angle P.A. = 155 deg and perpendicular to the radio/X-ray jet. The SE and NW components of the circumnuclear gas are connected to molecular gas found at larger radii. This gas appears as two parallel filaments at P.A. = 120 deg, which are coextensive with the long sides of the 3 kiloparsec parallelogram shape of the previously observed dust continuum, as well as ionized and pure rotational H2 lines. Spatial and kinematical asymmetries are apparent in both the circumnuclear and outer gas, suggesting non-coplanar and/or non-circular motions. We extend to inner radii (r < 200 pc) previously studied warped disk models built to reproduce the central parallelogram-shaped structure. Adopting the warped disk model we would confirm a gap in emission between the radii r = 200 - 800 pc (12'' - 50''), as has been suggested previously. Although this model explains this prominent feature, however, our 12CO(2-1) observations show relevant deviations from this model. Namely, the physical connection between the circumnuclear gas and that at larger radii, brighter SE and NW sides on the parallelogram-shaped feature, and an outer curvature of its long sides. Overall it resembles more closely an S-shaped morphology, a trend that is also found in other molecular species. Hence, we explore qualitatively the possible contribution of a weak bi-symmetric potential which would naturally explain these peculiarities.
Disentangling the Circumnuclear Environs of Centaurus A: III. An Inner Molecular Ring, Nuclear Shocks and the CO to warm H2 interface
利用ALMA观测数据,给出了半人马座A环核盘(CND,400 pc x 200 pc)中分子气体的分布和运动学,分辨率约为5 pc(0.3 arcsec),并阐明了活动星系核(AGN)的形成机制。CND内存在数十到一百秒差距尺度的多个细丝或流光,它们形成了一个环状结构,其未投影直径为9 x 6弧秒(162 pc x 108 pc),位置角PA = 155度。在核环内部,活动星系核两侧有两个长约30- 60秒差距的直的先导结构,在PA = 120度,旋转对称性为180度,位置-速度图较陡,这被解释为非圆运动引起的核激波。与附近的活动星系核不同的是,沿着丝状体,有几个致密的分子团呈现出低的HCN/HCO+(4-3)比值(~0.5)。在距活动星系核r = 20 pc的探测跃迁处,暗丝突然终止,但以前的近红外H2(J=1-0)S(1)图显示,它们在偶数K(~1000 K)处继续,以核螺旋的形式缠绕,并在r = 10 pc内与另一组沿N-S方向的对称暗丝形成内环结构。分子气体主要由非圆形运动控制,即在不同尺度上连续的激波前沿,在那里发生角动量的损失,这种机制可以有效地将强大的射电星系馈送到秒差距尺度。
MICONIC: The multiphase circumnuclear region of Centaurus A as seen with JWST/MIRI MRS observations. I. Spectral inventory and properties of the warm molecular disk
Sorbonne Université, CNRS, UMR 7095, Institut d’Astrophysique de Paris(索邦大学,法国国家科学研究中心,UMR 7095,巴黎天文台);SRON Netherlands Institute for Space Research(荷兰空间研究所);Leiden Observatory, Leiden University(莱顿天文台,莱顿大学);Observatoire de Paris, PSL University, Sorbonne Université, LUX(巴黎天文台,PSL大学,索邦大学,LUX);Centro de Astrobiología (CAB), CSIC-INTA(天体生物学中心(CAB),西班牙国家研究委员会-国家航空航天技术研究所);Department of Physics and Astronomy, Universiteit Gent(根特大学物理与天文学系);Telespazio UK for the European Space Agency (ESA)(欧洲航天局(ESA)旗下泰雷兹阿莱尼亚太空英国分公司);European Space Agency, c/o Space Telescope Science Institute(欧洲航天局,代管于太空望远镜科学研究所)
The molecular circumnuclear disk (CND) in Centaurus A: A multi-transition CO and [CI] survey with Herschel, APEX, JCMT, and SEST
我们介绍了赫歇尔空间天文台以及SEST、JCMT和APEX对NGC 128(Centaurus~A)中心致密环核盘的新CO和C^o线测量结果。Cen A中心的CO阶梯与星暴星系或活动星系核的CO阶梯有很大的不同。此外,Cen A [CI]中心发射线的相对强度也比其它星系的强得多。在同一视线范围内,致密的环核盘(CND)的CO表面亮度明显高于伸展得多的薄盘(ETD)。我们的LVG和PDR/XDR模型表明,如果通过紫外光子加热,则大部分CND气体相对较冷(25 - 80 K)且密度不高(~ 300 cm^{-3}),尽管在CND和ETD中都存在一些密度高得多的气体,其密度约为30 000 cm^{-3}。最后,在CND中也有高激发、高密度相(但在ETD中没有),要么是极端PDR的形式,但更可能是XDR的形式。Cen A CND的总气体质量为8.4 x 10^{7} M(太阳),不确定系数为2。CO-H2转换系数为4 x 10^{20} K km/s,也在2倍以内。
JWST reveals how black holes are fed: kiloparsec-scale multiphase filaments feed sub-kiloparsec circumnuclear disks
Université de Montréal(蒙特利尔大学);University of Michigan(密歇根大学);Princeton University(普林斯顿大学);Michigan State University(密歇根州立大学);Institut Trottier de recherche sur les exoplanètes(特鲁瓦耶系外行星研究所);Universidad Nacional Autónoma de México(墨西哥国立自治大学);University of Portsmouth(朴茨茅斯大学)
Molecular Abundance of the Circumnuclear Region Surrounding an Active Galactic Nucleus in NGC 1068 based on Imaging Line Survey in the 3-mm Band with ALMA
Spatially resolved molecular gas conditions in the circumnuclear disc of 3C 84
Leiden University(莱顿大学);ASTRON, the Netherlands Institute for Radio Astronomy(荷兰射电天文研究所);Kapteyn Astronomical Institute, University of Groningen(格罗宁根大学卡普坦天文研究所);Transdisciplinary Research Area (TRA) ‘Matter’/Argelander-Institut für Astronomie, University of Bonn(波恩大学跨学科研究领域‘物质’/阿尔根德天文学研究所);Department of Physics and Astronomy, University College London(伦敦大学学院物理与天文系)