EROSITA study of the 47~Tucanae globular cluster (2106.14535v2)

Abstract: Aims. We present the results of the analysis of five observations of the globular cluster 47 Tucanae (47 Tuc) with eROSITA (extended Roentgen Survey with an Imaging Telescope Array) on board Spektrum-Roentgen-Gamma (Spektr-RG, SRG). The aim of the work is the study of the X-ray population in the field of one of the most massive globular clusters in our Milky Way. We focused on the classification of point-like sources in the field of 47 Tuc. The unresolved dense core of 47 Tuc (1$'$.7 radius) and also the sources, which show extended emission are excluded in this study. Methods. We applied different methods of X-ray spectral and timing analysis together with multi wavelength studies for the classification of the X-rays sources in the field of 47 Tuc. Results. We detected 888 point-like sources in the energy range of 0.2-5.0 keV. We identified 126 background AGNs and 25 foreground stars. One of the foreground stars is classified as a variable M dwarf. We also classified 14 X-ray sources as members of 47 Tuc, including 1 symbiotic stars, 2 quiescent low mass X-ray binaries, and 4 cataclysmic variable. There are also 5 X-ray sources, which can either be a cataclysmic variable or a contact binary, and also 1 X-ray sources which can be an active binary (Type RS CVn). We identified one X-ray binary, which belongs to the Small Magellanic Cloud. Moreover, we calculated the X-ray luminosity function of 47 Tuc. No significant population that seems to belong to the globular cluster has been observed in the energy range of 0.5-2.0 keV using eROSITA observations.