XMM-Newton and Swift observations of XTE J1743-363^⋆

¹ ISDC Data Centre for Astrophysics, department of Astronomy, University of Geneva, Chemin d’Écogia 16, 1290 Versoix, Switzerland
e-mail: enrico.bozzo@unige.ch
² INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica – Palermo, via U. La Malfa 153, 90146 Palermo, Italy
³ INAF – Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate ( LC), Italy
⁴ International Space Science Institute (ISSI) Hallerstrasse 6, 3012 Bern, Switzerland
⁵ INAF – Osservatorio Astronomico di Roma, via Frascati 33, 00044 Roma, Italy

Received: 6 February 2013
Accepted: 6 June 2013

Abstract

XTE J1743-363 is a poorly known hard X-ray transient, which displays short and intense flares similar to those observed from supergiant fast X-ray transients. The probable optical counterpart shows spectral properties similar to those of an M8 III giant, thus suggesting that XTE J1743-363 belongs to the class of the symbiotic X-ray binaries class. In this paper we report on the first dedicated monitoring campaign of the source in the soft X-ray range with XMM-Newton and Swift /XRT. These observations confirmed the association of XTE J1743-363 with the previously suggested M8 III giant and the classification of the source as a member of the symbiotic X-ray binaries. In the soft X-ray domain, XTE J1743-363 displays a high absorption (~6 × 10²² cm^-2) and variability on time scales of hundreds to few thousand seconds, typical of wind-accreting systems. A relatively faint flare (peak X-ray flux 3 × 10^-11 erg/cm²/s) lasting ~4 ks is recorded during the XMM-Newton observation and interpreted in terms of the wind accretion scenario.