Constraints on Cosmic Rays Population in the Radio Halo of the M87 Galaxy from Gamma-Ray Observations
| Autor: | B. A. Nizamov, M. S. Pshirkov |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | JETP Letters. 115:245-250 |
| ISSN: | 1090-6487 0021-3640 |
| DOI: | 10.1134/s0021364022100137 |
| Popis: | We present results of our search for extended high-energy emission around the M87 galaxy, which is the central galaxy in the Virgo cluster. The M87 galaxy harbors extremely heavy supermassive black hole, $${{M}_{{BH}}} > 4 \times {{10}^{9}}{\kern 1pt} {{M}_{ \odot }}$$ and for the last 100 Myr experiences a period of increased activity that resulted in formation of extended lobes, which are prominent radio- and X-ray sources. We perform a search in 13 yr of the Fermi-LAT data in three energy bins: 0.1–1, 1–10, and 10–100 GeV. No significant detection of extended emission was achieved in any bin, with weak indication of a signal ($$ \sim {\kern 1pt} 2.5\sigma $$) in the last bin (10–100 GeV). We used γ-ray observations to put limits on cosmic rays population in the lobes, constraining their fraction X in comparison to the thermal energy of the hot gas. Depending on the value of spectral index, for electrons $${{X}_{e}} < (0.1{-} 0.2)$$ and protons were constrained at $${{X}_{p}} < (0.2{-} 0.5)$$ level. We confirm that cosmic rays is a subdominant component of the lobes, which are dominated by thermal gas. |
| Databáze: | OpenAIRE |
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