EVIDENCE FOR A PARSEC-SCALE JET FROM THE GALACTIC CENTER BLACK HOLE: INTERACTION WITH LOCAL GAS

• Main Authors: Li, Zhiyuan (Author), Morris, Mark R. (Author), Baganoff, Frederick K (Author)
• Other Authors: MIT Kavli Institute for Astrophysics and Space Research (Contributor), Baganoff, Frederick K. (Contributor)
• Format: Article
• Language: English
• Published: Institute of Physics/American Astronomical Society, 2015-02-13T15:23:44Z.
• Subjects: Article
• Online Access: Get fulltext

Despite strong physical reasons that they should exist and decades of searching, jets from the Galactic center black hole, Sgr A*, have not yet been convincingly detected. Based on high-resolution Very Large Array images and ultra-deep imaging-spectroscopic data produced by the Chandra X-ray Observatory, we report new evidence for the existence of a parsec-scale jet from Sgr A*, by associating a linear feature G359.944-0.052, previously identified in X-ray images of the Galactic center, with a radio shock front on the Eastern Arm of the Sgr A West H II region. We show that the shock front can be explained in terms of the impact of a jet having a sharp momentum peak along the Galaxy's rotation axis, whereas G359.944-0.052, a quasi-steady feature with a power-law spectrum, can be understood as synchrotron radiation from shock-induced ultra-relativistic electrons cooling in a finite post-shock region downstream along the jet path. Several interesting implications of the jet properties are discussed.
National Science Foundation (U.S.) (NSF grant AST-0909218)
Space Telescope Science Institute (U.S.) (SAO grant GO3-14099X, under NAS8-03060)