Abstract
The detection of an X-ray filament associated with the radio filament G0.173-0.42 adds to four other non-thermal radio filaments with X-ray counterparts, amongst the more than 100 elongated radio structures that have been identified as synchrotron-emitting radio filaments in the inner couple of degrees of the Galactic centre. The synchrotron mechanism has also been proposed to explain the emission from X-ray filaments. However, the origin of radio filaments and the acceleration sites of energetic particles to produce synchrotron emission in radio and X-rays remain mysterious. Using MeerKAT, VLA, Chandra, WISE, and Spitzer, we present structural details of G0.173-0.42 which consists of multiple radio filaments, one of which has an X-ray counterpart. A faint oblique radio filament crosses the radio and X-ray filaments. Based on the morphology, brightening of radio and X-ray intensities, and radio spectral index variation, we argue that a physical interaction is taking place between two magnetized filaments.We consider that the reconnection of the magnetic field lines at the interaction site leads to the acceleration of particles to GeV energies. We also argue against the synchrotron mechanism for the X-ray emission due to the short ∼30 yr lifetime of TeV relativistic particles. Instead, we propose that the inverse Compton scattering mechanism is more likely to explain the X-ray emission by upscattering of seed photons emitted from a 106 L⊙ star located at the northern tip of the X-ray filament.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3142-3150 |
| Number of pages | 9 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 500 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 1 2021 |
Funding
This work is partially supported by the grant AST-0807400 from the National Science Foundation. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. IH acknowledges support from the UK Science and Technology Facilities Council (ST/N000919/1), the Oxford Hintze Centre for Astrophysical Surveys which is funded through generous support from the Hintze Family Charitable Foundation, and a visiting Professorship from SARAO. We acknowledge use of the Inter-University Institute for Data Intensive Astronomy (IDIA) data intensive research cloud for data processing. IDIA is a South African university partnership involving the University of Cape Town, the University of Pretoria, and the University of the Western Cape. MW thanks the Cherrybrook Research Institute for hospitality. The authors acknowledge the Centre for High Performance Computing (CHPC), South Africa, for providing computational resources to this research project.
Keywords
- Accretion
- Accretion discs
- Black hole physics
- Galaxy: Centre
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science