Exploring the Nature of the Galactic Center Gamma-Ray Source with the Cherenkov Telescope Array

Abstract

Observations from multiple gamma-ray telescopes have uncovered a high energy gamma-ray source spatially coincident with the Galactic center. Recently, a compelling model for the broad-band gamma-ray emission has been formulated which posits that high energy protons emanating from Sgr A* could produce gamma-rays through pion decays resulting from inelastic collisions with the traversed interstellar gas in the region. Models of the gas distribution in the Galactic center region imply that the resulting gamma-ray morphology would be observed as a point source with all current telescopes, but that the upcoming Cherenkov Telescope Array (CTA) may be able to detect an extended emission profile with an unmistakable morphology. Here, we critically evaluate this claim, employing a three dimensional gas distribution model and a detailed Monte Carlo simulation, and using the anticipated effective area and angular resolution of CTA. We find that the impressive angular resolution of CTA will be key to test hadronic emission models conclusively against, for example, point source or dark matter annihilation scenarios. We comment on the relevance of this result for searches for dark matter annihilation in the Galactic center region.

7 pages, 6 figures, ApJ 760:23

References in corpus (7)

• Observations of the Crab Nebula with H.E.S.S
• On The Origin Of The Gamma Rays From The Galactic Center
• TeV gamma-rays and the largest masses and annihilation cross sections of neutralino dark matter
• The Morphology of Hadronic Emission Models for the Gamma-Ray Source at the Galactic Center
• Interstellar gas within $\sim 10$ pc of Sgr A${}^{\ast }$
• A Testable the Stochastic Acceleration Model for Flares in Sagittarius A*
• A Possible Link Between the Galactic Center HESS Source and Sgr A*

Cited by in corpus (10)

• Cosmic Ray Protons in the Inner Galaxy and the Galactic Center Gamma-Ray Excess
• Extended gamma-ray emission from Coy Dark Matter
• Challenges in Explaining the Galactic Center Gamma-Ray Excess with Millisecond Pulsars
• A Possible Explanation of Low Energy $\gamma$-ray Excess from Galactic Centre and Fermi Bubble by a Dark Matter Model with Two Real Scalars
• Indirect Detection of Dark Matter with gamma rays
• Neutrino Lighthouse at Sagittarius A*
• Non-thermal WIMPs as "Dark Radiation" in Light of ATACAMA, SPT, WMAP9 and Planck
• Gamma rays from the Galactic Centre region: a review
• Separating astrophysical sources from indirect dark matter signals
• Cosmic-Ray Models of the Ridge-Like Excess of Gamma Rays in the Galactic Center