Constraints on Cosmic Rays Population in the Radio Halo of the M87 Galaxy from Gamma-Ray Observations

• Published in: JETP letters 2022, Vol.115 (5), p.245-250
• Main Authors: Nizamov, B. A., Pshirkov, M. S.
• Format: Article
• Language: English
• Subjects: Astrophysics and Cosmology; Atomic; Biological and Medical Physics; Biophysics; Constraints; Cosmic rays; Elliptical galaxies; Emission; Gamma rays; High energy astronomy; Lobes; Molecular; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Quantum Information Technology; Radio sources (astronomy); Solid State Physics; Spintronics; Supermassive black holes; Thermal energy; Virgo galactic cluster; X ray sources
• ISSN: 0021-3640; 1090-6487
• DOI: 10.1134/S0021364022100137

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, 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 ( ) 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 and protons were constrained at level. We confirm that cosmic rays is a subdominant component of the lobes, which are dominated by thermal gas.