Nature of the Galactic centre NIR-excess sources. I. What can we learn from the continuum observations of the DSO/G2 source?
Nature of the Galactic centre NIR-excess sources. I. What can we learn from the continuum observations of the DSO/G2 source?
复制标题
银河系中心近红外过量源的性质。
DOI：
10.1051/0004-6361/201730532
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
A. Zensus
中科院分区：
文献类型：
--
作者：
M. Zajavcek;S. Britzen;A. Eckart;B. Shahzamanian;G. Busch;V. Karas;M. Parsa;F. Peißker;M. Dovvciak;M. Subroweit;F. Dinnbier;A. Zensus
在银河系中心围绕超大质量黑洞（Sgr A*）运行的尘埃S-星团天体（DSO/G2）已经在近红外连续谱和线发射中被监测到。关于这个天体的性质和紧凑性一直存在争议：将其解释为气体云或尘埃笼罩的星星。最近的分析偏振测量数据在$K_{\rm s}$波段（$2.2\，{\rm \mu m}$），使我们能够把进一步的约束的几何形状的DSO。本文的目的是约束的性质和几何的DSO。我们比较了三维辐射传输模型的DSO与近红外连续光谱数据，包括偏振。在分析中，我们使用基本的尘埃连续辐射传输理论实现的三维蒙特卡罗代码。此外，我们实现了两体问题力学和非热过程理论的分析结果。我们提出了一个复合模型的DSO -尘埃笼罩的星星，由恒星源，尘埃，光学厚信封，双极腔，和弓激波。该方案可以匹配近红外总以及所观察到的光谱能量分布（SED）的偏振特性。理论上，SED也可以用一个年轻的脉冲星风星云来解释，这个星云通常由于磁层同步辐射而表现出很大的线性偏振度。近红外偏振测量数据结合辐射传输模型的分析表明，DSO是一个独特的源紧凑的性质在S集群$（r \lesssim 0.04\，{\rm pc}）$。它很可能是一颗年轻的恒星，被埋在一个非球形的尘埃包层中，其组成部分包括光学厚度的尘埃包层、双极空腔和弓形激波。或者，连续辐射可能是由于年轻中子星星及其风星云的存在而产生的非热源。
The Dusty S-cluster Object (DSO/G2) orbiting the supermassive black hole (Sgr A*) in the Galactic centre has been monitored in both near-infrared continuum and line emission. There has been a dispute about the character and the compactness of the object: interpreting it as either a gas cloud or a dust-enshrouded star. A recent analysis of polarimetry data in $K_{\rm s}$-band ($2.2\,{\rm \mu m}$) allows us to put further constraints on the geometry of the DSO. The purpose of this paper is to constrain the nature and the geometry of the DSO. We compare 3D radiative transfer models of the DSO with the NIR continuum data including polarimetry. In the analysis, we use basic dust continuum radiative transfer theory implemented in the 3D Monte Carlo code Hyperion. Moreover, we implement analytical results of the two-body problem mechanics and the theory of non-thermal processes. We present a composite model of the DSO -- a dust-enshrouded star that consists of a stellar source, dusty, optically thick envelope, bipolar cavities, and a bow shock. This scheme can match the NIR total as well as polarized properties of the observed spectral energy distribution (SED). The SED may be also explained in theory by a young pulsar wind nebula that typically exhibits a large linear polarization degree due to magnetospheric synchrotron emission. The analysis of NIR polarimetry data combined with the radiative transfer modelling shows that the DSO is a peculiar source of compact nature in the S cluster $(r \lesssim 0.04\,{\rm pc})$. It is most probably a young stellar object embedded in a non-spherical dusty envelope, whose components include optically thick dusty envelope, bipolar cavities, and a bow shock. Alternatively, the continuum emission could be of a non-thermal origin due to the presence of a young neutron star and its wind nebula.
DOI：
10.1088/0004-637x/750/1/58
发表时间：
2012-01
期刊：
The Astrophysical Journal
影响因子：
--
作者：
A. Burkert;M. Schartmann;C. Alig;S. Gillessen;R. Genzel;T. Fritz;F. Eisenhauer
通讯作者：
A. Burkert;M. Schartmann;C. Alig;S. Gillessen;R. Genzel;T. Fritz;F. Eisenhauer
影响因子：
4.8
作者：
I. Mendigut'ia;R. Oudmaijer;E. Rigliaco;J. Fairlamb;N. Calvet;J. Muzerolle;N. Cunningham;S. Lumsden
通讯作者：
I. Mendigut'ia;R. Oudmaijer;E. Rigliaco;J. Fairlamb;N. Calvet;J. Muzerolle;N. Cunningham;S. Lumsden