2023MNRAS.525.1553B -
Mon. Not. R. Astron. Soc., 525, 1553-1561 (2023/October-2)
X-ray emission from Westerlund 2 detected by SRG/ART-XC and Chandra: search for radiation of TeV leptons.
BYKOV A.M., UVAROV Y.A., KALYASHOVA M.E., BADMAEV D.V., LAPSHOV I.Y., LUTOVINOV A.A., MEREMINSKIY I.A. and SEMENA A.N.
Abstract (from CDS):
We present the results of current observations of the young compact cluster of massive stars Westerlund 2 (Wd2) with the Mikhail Pavlinsky ART-XC telescope aboard the Spectrum-Roentgen-Gamma (SRG) observatory which we analysed together with the archival Chandra data. In general, Wd2 was detected over the whole electromagnetic spectrum including high-energy gamma rays, which revealed a cosmic ray acceleration in this object to the energies up to tens of TeV. The detection of Wd2 with ART-XC allowed us to perform a joint spectral analysis together with the high resolution Chandra observations of the diffuse emission from a few selected regions in the vicinity of the Wd2 core in the 0.4-20 keV range. To fit the Wd2 X-ray spectrum above a few keV one needs either a non-thermal power-law emission component, or a hot plasma with temperatures ∼ 5 keV. Our magnetohydrodynamic modelling of the plasma flows in Wd2 shows substantially lower electron temperatures in the system and thus the presence of the non-thermal component is certainly preferable. A kinetic model of the particle acceleration demonstrated that the non-thermal component may originate from the synchrotron radiation of multi-TeV electrons and positrons produced in Wd2 in accordance with the TeV photons detection from the source.
Abstract Copyright:
© 2023 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society
Journal keyword(s):
MHD - stars: massive - stars: winds - ISM: bubbles - galaxies: star clusters: general - X rays: ISM
Simbad objects:
12
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2023MNRAS.525.1553B and select 'bookmark this link' or equivalent in the popup menu