The Post-pericenter Evolution of the Galactic Center Source G2
The Post-pericenter Evolution of the Galactic Center Source G2
复制标题
银河中心源G2的近中心后演化
DOI：
10.3847/1538-4357/aa6e00
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. Fellenberg
中科院分区：
文献类型：
--
作者：
P. Plewa;S. Gillessen;O. Pfuhl;F. Eisenhauer;R. Genzel;A. Burkert;J. Dexter;M. Habibi;E. George;T. Ott;I. Waisberg;S. Fellenberg
2014年初，快速移动的近红外源G2最接近银河系中心的超大质量黑洞Sgr A*。我们报告了2015年和2016年ESO VLT上的SINFONI积分场光谱仪和NACO成像仪获得的新观测结果，揭示了G2电离气体成分和尘埃成分在此事件发生后的演变。Brγ线发射的空间分辨动力学可以用一个测试粒子云的弹道运动和潮汐剪切来解释，这个测试粒子云在过去的12年里一直沿着黑洞周围的一个高度偏心的开普勒轨道运行。假设G2是一个球体云，在一个静止且均匀的大气中移动，由于没有检测到阻力或与内部吸积区热气体的任何强流体动力相互作用，因此在最接近的距离（）处，环境密度小于几。尘埃连续辐射在L波段无法分辨，但与Brγ辐射的位置保持一致。Brγ和L′发射的总光度保持不变，在测量不确定度范围内。G2的性质和起源很可能与前体源G1有关，因为它们的轨道演化相似，尽管不完全相同。这两个物体也可能与拖尾结构有关，该结构在很大的位置和径向速度范围内连续连接到G2。
In early 2014, the fast-moving near-infrared source G2 reached its closest approach to the supermassive black hole Sgr A* in the Galactic center. We report on the evolution of the ionized gaseous component and the dusty component of G2 immediately after this event, revealed by new observations obtained in 2015 and 2016 with the SINFONI integral field spectrograph and the NACO imager at the ESO VLT. The spatially resolved dynamics of the Brγ line emission can be accounted for by the ballistic motion and tidal shearing of a test-particle cloud that has followed a highly eccentric Keplerian orbit around the black hole for the last 12 years. The non-detection of a drag force or any strong hydrodynamic interaction with the hot gas in the inner accretion zone limits the ambient density to less than a few at the distance of closest approach ( ), assuming G2 is a spherical cloud moving through a stationary and homogeneous atmosphere. The dust continuum emission is unresolved in L′-band, but stays consistent with the location of the Brγ emission. The total luminosity of the Brγ and L′ emission has remained constant to within the measurement uncertainty. The nature and origin of G2 are likely related to that of the precursor source G1, since their orbital evolution is similar, though not identical. Both objects are also likely related to a trailing tail structure, which is continuously connected to G2 over a large range in position and radial velocity.
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