Detecting Stars at the Galactic Centre via Synchrotron Emission

Abstract

Stars orbiting within 1$\arcsec$ of the supermassive black hole in the Galactic Centre, Sgr A*, are notoriously difficult to detect due to obscuration by gas and dust. We show that some stars orbiting this region may be detectable via synchrotron emission. In such instances, a bow shock forms around the star and accelerates the electrons. We calculate that around the 10 GHz band (radio) and at 10${}^{14}$ Hz (infrared) the luminosity of a star orbiting the black hole is comparable to the luminosity of Sgr A*. The strength of the synchrotron emission depends on a number of factors including the star's orbital velocity. Thus, the ideal time to observe the synchrotron flux is when the star is at pericenter. The star S2 will be $\sim 0.015\arcsec$ from Sgr A* in 2018, and is an excellent target to test our predictions.

5 pages, 3 figures, accepted for publication in MNRAS

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Cited by in corpus (7)

• Massive binary star mergers in galactic nuclei: implications for blue stragglers, binary S-stars and gravitational waves
• Modelling Accretion Disk and Stellar Wind Interactions: the Case of Sgr A*
• ALMA and VLA observations of emission from the environment of Sgr A*
• Constraining the accretion flow density profile near Sgr A* using the $L^{\prime }$-band emission of the S2 star
• Simulating the pericentre passage of the Galactic centre star S2
• X-ray constraint for the unseen companion of V723 Mon: it is a mass-gap black hole rather than binary neutron stars
• Non-thermal emission from fall-back clouds in the Broad-Line Region of Active Galactic Nuclei