SRGA J124404.1–632232/SRGU J124403.8–632231: New X-ray pulsar discovered in the all-sky survey by the SRG

¹ Institut für Astronomie und Astrophysik, Sand 1, 72076 Tübingen, Germany
e-mail: doroshv@astro.uni-tuebingen.de
² Max-Planck-Institut für extraterrestrische Physik, Gießenbachstraße 1, 85748 Garching, Germany
³ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
⁴ Dr. Karl Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
⁵ South African Astronomical Observatory, PO Box 9, Observatory Rd, Observatory 7935, South Africa
⁶ Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa
⁷ Space Research Institute (IKI) of Russian Academy of Sciences, Prosoyuznaya ul 84/32, 117997 Moscow, Russian Federation
⁸ Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warsaw, Poland
⁹ Southern African Large Telescope, PO Box 9, Observatory Rd, Observatory 7935, South Africa

Received: 21 April 2021
Accepted: 13 July 2021

Abstract

Ongoing all-sky surveys by the eROSITA and the Mikhail Pavlinsky ART-XC telescopes on board the Spectrum-Roentgen-Gamma (SRG) mission have already revealed over a million of X-ray sources. One of them, SRGA J124404.1–632232/SRGU J124403.8–632231, was detected as a new source in the third (of the planned eight) consecutive X-ray surveys by ART-XC. Based on the properties of the identified optical counterpart, it was classified as a candidate X-ray binary. We report on the follow-up observations of this source with the Nuclear Spectroscopic Telescope Array, the Neil Gehrels Swift Observatory, and the Southern African Large Telescope, which allowed us to unambiguously confirm the initial identification and establish SRGU J124403.8–632231 as a new X-ray pulsar with a spin period of ~538 s and a Be-star companion, making it one of the first Galactic X-ray pulsars discovered by the SRG.