An embedded circumnuclear disk in Mrk 273
An embedded circumnuclear disk in Mrk 273
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Mrk 273 中嵌入的环核圆盘
DOI：
10.1051/0004-6361:20040998
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发表时间：
2004
影响因子：
6.5
通讯作者：
W. Baan
中科院分区：
文献类型：
--
作者：
H. Klockner;W. Baan
利用甚长基线干涉仪（VLBI）和Westerbork干涉仪对Mrk 273中的羟基超脉泽辐射进行了不同空间分辨率的射电观测。欧洲VLBI观测网（EVN）在1.6 GHz进行了线观测和连续观测，并在中心角秒（2）区域显示了许多不同的结构成分。观察到的连续发射显示出三个突出的区域，平坦和陡峭的光谱指数。EVN测量所检测到的羟基（OH）发射仅占Mrk 273总OH发射的12%，但它确实显示出与WSRT观测相同的主导1667 MHz线发射分量。脉泽发射的空间分布提供了核区域分子环境的高分辨率视图。OH辐射只在北方核的一个独特射电源上被探测到，其空间范围为108秒差距。OH辐射只是部分叠加在射电连续谱上，与近红外辐射源有关。微波激射器的低泵浦效率和OH主线比表明，这种发射起源于光学薄和不饱和的微波激射器环境与一个复杂的泵浦方案，不能用辐射红外泵浦与一个单一的尘埃温度来解释。特定的线发射模式和视线速度表明了边缘圆盘/环面的有组织结构，其开普勒旋转围绕着一个中心物体，其结合质量为1.39 +/- 0.16 x 10（9）M圆点。
Radio observations using very long baseline interferometry (VLBI) and the Westerbork interferometer have been carried out to study the hydroxyl Megamaser emission in Mrk 273 at different spatial resolutions. Line and continuum observations were carried out by the European VLBI network (EVN) at 1.6 GHz and display a number of distinct structural components in the central arcsec(2) region. The observed continuum emission shows three prominent regions with both flat and steep spectral indexes. The hydroxyl (OH) emission detected by the EVN measurements accounts for only 12 percent of the total OH emission in Mrk 273, but it does show the same dominant 1667 MHz line emission components as the WSRT observations. The spatial distribution of the maser emission provides a high resolution view of the molecular environment in the nuclear region. The OH emission has only been detected toward a distinct radio source in the northern nucleus with a spatial extent of 108 pc. The OH emission is only partially superposed on the radio continuum and is associated with the near-infrared emission source. The low pump efficiency of the maser and the OH main-line ratio suggest that this emission originates in an optically thin and unsaturated maser environment with a complex pumping scheme that cannot be explained by radiative infrared pumping with a single dust temperature. The specific line emission pattern and the line-of-sight velocities indicate the organized structure of an edge-on disk/TORUS with a Keplerian rotation surrounding a central object with a binding mass of 1.39 +/- 0.16 x 10(9) M-circle dot.