Vol 15, No 12 (2015) / Liu

On the diffuse soft X-ray emission from the nuclear region of M51

Ji-Ren Liu, Shu-De Mao

Abstract

We present an analysis of the diffuse soft X-ray emission from the nuclear region of M51 combining both XMM-Newton RGS and Chandra data. Most of the RGS spectrum of M51 can be fitted with a thermal model with a temperature of ~0.5 keV except for the O VII triplet, which is forbidden-line dominated. The Fe L-shell lines peak around the southern cloud, where the O VIII and N VII Lyα lines also peak. In contrast, the peak of the O VII forbidden line is about 10 ′′ offset from that of the other lines, indicating that it is from a spatially distinct component. The spatial distribution of the O VII triplet mapped by the Chandra data shows that most of the O VII triplet flux is located at faint regions near edges, instead of the southern cloud where other lines peak. This distribution of the O VII triplet is inconsistent with the photoionization model. Other mechanisms that could produce the anomalous O VII triplet, including a recombining plasma and charge exchange X-ray emission, are discussed.

Keywords


atomic processes — plasmas — ISM: jets and outflows — galaxies: Seyfert — galaxies: individual: M51 (NGC 5194) — X-rays: ISM

Full Text:

PDF


DOI: https://doi.org/10.1088/1674–4527/15/12/004

Refbacks

  • There are currently no refbacks.