NuSTAR view of the central region of M 31

Abstract

Our neighbouring large spiral galaxy, the Andromeda galaxy (M 31 or NGC 224), is an ideal target to study the X-ray source population of a nearby galaxy. NuSTAR observed the central region of M 31 in 2015 and allows studying the population of X-ray point sources at energies higher than 10 keV. Based on the source catalogue of the large XMM-Newton survey of M 31, we identified counterparts to the XMM-Newton sources in the NuSTAR data. The NuSTAR data only contain sources of a brightness comparable (or even brighter) than the selected sources that have been detected in XMM-Newton data. We investigate hardness ratios, spectra and long-term light curves of individual sources obtained from NuSTAR data. Based on our spectral studies we suggest four sources as possible X-ray binary candidates. The long-term light curves of seven sources that have been observed more than once show low (but significant) variability.

14 pages, 8 figures, accepted by MNRAS

References in corpus (7)

• X-ray monitoring of optical novae in M31 from July 2004 to February 2005
• A study of the population of LMXBs in the bulge of M31
• Time variability of X-ray sources in the M 31 centre field
• An X-ray spectral survey of the disc of M31 with XMM-Newton
• Identification of the Hard X-ray Source Dominating the E > 25 keV Emission of the Nearby Galaxy M31
• Three X-ray transients in M31 observed with Swift
• Discovery of periodic dips in the brightest hard X-ray source of M31 with EXTraS

Cited by in corpus (2)

• New Constraints on Sterile Neutrino Dark Matter from $NuSTAR$ M31 Observations
• Decaying fermionic warm dark matter and XENON1T electronic recoil excess