X-ray emission from Westerlund 2 detected by SRG/ART-XC and Chandra: search for radiation of TeV leptons
| Autor: | Bykov, A. M., Uvarov, Yu. A., Kalyashova, M. E., Badmaev, D. V., Lapshov, I. Yu., Lutovinov, A. A., Mereminskiy, I. A., Semena, A. N. |
|---|---|
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | MNRAS 525 (2023) 1553-1561 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1093/mnras/stad2356 |
| Popis: | We present the results of current observations of the young compact cluster of massive stars Westerlund 2 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, Westerlund 2 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 Westerlund 2 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 Westerlund 2 core in the 0.4 - 20 keV range. To fit the Westerlund 2 X-ray spectrum above a few keV one needs either a non-thermal power-law emission component, or a hot plasma with temperatures $\sim$ 5 keV. Our magnetohydrodynamic modeling of the plasma flows in Westerlund 2 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 Westerlund 2 in accordance with the TeV photons detection from the source. Comment: 10 pages, 6 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|