IGR J17451–3022: A dipping and eclipsing low mass X-ray binary

¹ ISDC Data Centre for Astrophysics, Chemin d’Ecogia 16, 1290 Versoix, Switzerland
e-mail: enrico.bozzo@unige.ch
² Centrum Astronomiczne im. M. Kopernika, Bartycka 18, 00-716 Warszawa, Poland
³ Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, NJ 08544 Princeton, USA
⁴ INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica – Palermo, via U. La Malfa 153, 90146 Palermo, Italy
⁵ Institut de Ciències de l’Espai (IEEC-CSIC), Campus UAB, carrer de Can Magrans, S/N 08193, Cerdanyola del Vallès, Barcelona, Spain
⁶ Astrohpysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
⁷ Universitá degli Studi di Cagliari, Dipartimento di Fisica, SP Monserrato-Sestu, KM 0.7, 09042 Monserrato, Italy
⁸ INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica – Milano, via E. Bassini 15, 20133 Milano, Italy
⁹ Dipartimento di Fisica e Chimica, Universitá di Palermo, via Archirafi 36, 90123 Palermo, Italy
¹⁰ Department of Physics, Oregon State University, 301 Weniger Hall, Corvallis, OR 97331, USA
¹¹ Max-Planck-Institut für Extraterretrische Physik, Giessenbachstrasse, 85748 Garching, Germany

Received: 4 October 2015
Accepted: 7 March 2016

Abstract

In this paper we report on the available X-ray data collected by INTEGRAL, Swift, and XMM-Newton during the first outburst of the INTEGRAL transient IGR J17451–3022, discovered in 2014 August. The monitoring observations provided by the JEM-X instruments on board INTEGRAL and the Swift /XRT showed that the event lasted for about 9 months and that the emission of the source remained soft for the entire period. The source emission is dominated by a thermal component (kT ~ 1.2 keV), most likely produced by an accretion disk. The XMM-Newton observation carried out during the outburst revealed the presence of multiple absorption features in the soft X-ray emission that could be associated with the presence of an ionized absorber lying above the accretion disk, as observed in many high inclination, low mass X-ray binaries. The XMM-Newton data also revealed the presence of partial and rectangular X-ray eclipses (lasting about 820 s) together with dips. The rectangular eclipses can be associated with increases in the overall absorption column density in the direction of the source. The detection of two consecutive X-ray eclipses in the XMM-Newton data allowed us to estimate the source orbital period at P_orb = 22620.5^+2.0_-1.8 s (1σ confidence level).