Iron emission line from the spiral galaxy M101

TL;DR

This study analyzes Suzaku data of galaxy M101, detecting a strong iron emission line indicating hot thermal plasma, and discusses its possible origins.

Contribution

First detection of a prominent iron emission line in M101's central region using Suzaku data, revealing hot plasma presence.

Findings

Detected iron K-line at 6.72 keV in M101

Estimated iron line luminosity as (2-12)×10^{37} erg s^{-1}

Indicates existence of hot thermal plasma in the galaxy's center

Abstract

Archival Suzaku data of the face-on spiral galaxy M101 were analyzed. An intense emission line at 6.72^{+0.10}_{-0.12} keV was detected in the central region. This line is identified with a K-line from He-like iron, which indicates the existence of a thin thermal plasma with a temperature of several keV. The iron line luminosity within the central 5 arcmin radius region is estimated to be (2-12)x10^{37} erg s^{-1}. The origin of the iron emission line is discussed.