English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We carried out new observations of two fields in the northern ring of M31with XMM-Newton with two exposures of 100 ks each and obtained a complete listof X-ray sources down to a sensitivity limit of ~7 x 10^34 erg s^-1 (0.5 - 2.0keV). The major objective of the observing programme was the study of the hotphase of the ISM in M31. The analysis of the diffuse emission and the study ofthe ISM is presented in a separate paper. We analysed the spectral propertiesof all detected sources using hardness ratios and spectra if the statisticswere high enough. We also checked for variability. We cross-correlated thesource list with the source catalogue of a new survey of the northern disc ofM31 carried out with Chandra and Hubble (Panchromatic Hubble AndromedaTreasury, PHAT) as well as with other existing catalogues. We detected a totalof 389 sources, including 43 foreground stars and candidates and 50 backgroundsources. Based on the comparison to the Chandra/PHAT survey, we classify 24hard X-ray sources as new candidates for X-ray binaries (XRBs). In total, weidentified 34 XRBs and candidates and 18 supernova remnants (SNRs) andcandidates. Three of the four brightest SNRs show emission mainly below 2 keV,consistent with shocked ISM. The spectra of two of them also require anadditional component with a higher temperature. The SNR [SPH11] 1535 has aharder spectrum and might suggest that there is a pulsar-wind nebula inside theSNR. We find five new sources showing clear time variability. We also studiedthe spectral properties of the transient source SWIFT J004420.1+413702, whichshows significant variation in flux over a period of seven months (June 2015 toJanuary 2016) and associated change in absorption. Based on the likely opticalcounterpart detected in the Chandra/PHAT survey, the source is classified as alow-mass X-ray binary.

Deep XMM-Newton observations of the northern disc of M31. I. Source catalogue