Optical and X-ray observations of candidate isolated neutron stars in the G315.4-2.3 SNR

Abstract

G315.4-2.3 is a young Galactic supernova remnant (SNR), whose identification as the remains of a Type-II supernova (SN) explosion has been debated for a long time. In particular, recent multi-wavelength observations suggest that it is the result of a Type Ia SN, based on spectroscopy of the SNR shell and the lack of a compact stellar remnant.However, two X-ray sources, one detected by Einstein and ROSAT (Source V) and the other by Chandra (Source N) have been proposed as possible isolated neutron star candidates. In both cases, no clear optical identification was available and, therefore, we performed an optical and X-ray study to determine the nature of these two sources. Based on Chandra astrometry, Source V is associated with a bright V~14 star, which had been suggested based on the less accurate ROSAT position. Similarly, from VLT archival observations, we found that Source N is associated with a relatively bright star ($V=20.14$). These likely identifications suggest that both X-ray sources cannot be isolated neutron stars.

4 pages, 4 figures, accepted for publication in MNRAS

References in corpus (4)

• The Second-Generation Guide Star Catalog: Description and Properties
• RCW 86: A Type Ia Supernova in a Wind-Blown Bubble
• A time-variable, phase-dependent emission line in the X-ray spectrum of the isolated neutron star RX J0822-4300
• XMM-Newton and ESO observations of the two unidentified gamma-ray sources 3EG J0616-3310 and 3EG J1249-8330

Cited by in corpus (2)

• A solar-type star polluted by calcium-rich supernova ejecta inside the supernova remnant RCW 86
• A new wideband radio polarization observation of the Supernova Remnant G315.4$-$2.3