A Deep Chandra View of a Candidate Parsec-scale Jet from the Galactic Center Supermassive Black Hole

被引：12

作者：

Zhu, Zhenlin ^{[1
,2
]}

Li, Zhiyuan ^{[1
,2
]}

Morris, Mark R. ^{[3
]}

Zhang, Shuo ^{[4
]}

Liu, Siming ^{[5
]}

机构：

[1] Nanjing Univ, Sch Astron & Space Sci, Nanjing 210023, Jiangsu, Peoples R China

[2] Nanjing Univ, Key Lab Modern Astron & Astrophys, Minist Educ, Nanjing 210023, Jiangsu, Peoples R China

[3] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA

[4] MIT, Kavli Inst Astrophys & Space Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA

[5] Chinese Acad Sci, Purple Mt Observ, Nanjing 210034, Jiangsu, Peoples R China

来源：

ASTROPHYSICAL JOURNAL | 2019年 / 875卷 / 01期

基金：

美国国家科学基金会;

关键词：

black hole physics; Galaxy: center; ISM: jets and outflows; radiation mechanisms: non-thermal; X-rays: individual (G359.944-0.052); X-RAY FLARE; SGR A-ASTERISK; SYSTEMATIC CHANDRA; IONIZED-GAS; XMM-NEWTON; SAGITTARIUS; RADIO; MODEL; CATALOG; A(STAR);

D O I：

10.3847/1538-4357/ab0e05

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We have investigated the linear X-ray filament, G359.944-0.052, previously identified as a likely X-ray counterpart of a parsec-scale jet from the Galactic Center supermassive black hole (SMBH) Sagittarius A* (Sgr A*), using a total of similar to 5.6 Ms ultra-deep Chandra observations taken from 1999 September to 2017 July. This unprecedented data set enables us to examine flux and spectral variations that might be related to intrinsic properties of the weakly accreting SMBH. We find no flux or spectral variation in G359.944-0.052 after the G2 periapsis passage around early 2014; however, a moderate flux increase of similar to 2 sigma significance might be associated with the periapsis passage of G1 in early 2001. The filament exhibits an unusually hard spectrum (photon index less than or similar to 1) in its portion closest to Sgr A* (i.e., near side) and a significant spectral softening in the more distant portion, which can be interpreted as synchrotron cooling of the relativistic electrons moving along the jet path. In particular, the hard spectrum of the near side suggests a piling up of quasi-monoenergetic electrons caused by rapid radiative cooling. The spectral and temporal properties of G359.944-0.052 strengthen the case for it being the X-ray counterpart of a jet launched by Sgr A*.

引用

页数：12