SRG/ART-XC and NuSTAR observations of the Be X-ray pulsar Swift J1626.6-5156
ATel #14462; S. Molkov(1), A. Lutovinov(1), S. Tsygankov(2, 1), V. Doroshenko(3), I. Mereminskiy(1), A. Semena(1)(1: IKI RAS, Russia, 2: University of Turku, Finland, 3: IAAT, Germany)
on 16 Mar 2021; 12:22 UT
Credential Certification: Ilya Mereminskiy (i.a.mereminskiy@gmail.com)
Subjects: X-ray, Neutron Star, Transient, Pulsar
During the ongoing third all-sky survey, on 12 Mar 2021, the Mikhail
Pavlinsky ART-XC
telescope onboard SRG scanned the Swift J1626.6-5156 location sky region
with
an effective exposure of ~25 seconds and detected the source at the high
significance
level with the flux of ~20 mCrab in the 4-12 keV energy band. In
previous two
surveys the source flux was below the ART-XC sensitivity. We confirm the
new outburst
of Swift J1626.6-5156, that had been also detected recently with
MAXI/GSC (ATel #14454) and NICER (ATel #14457) instruments.
Following ART-XC detection we requested follow-up observations of the
source
with NuSTAR. Observations were carried out on 13-14 Mar., 2021. The
source was
clearly detected up to 50 keV, along with the pulse period of 15.3396(1) s.
The NuSTAR 3-50 keV averaged energy spectrum can be well fitted with the
absorbed
(nH~3.6x1022 cm-2) COMPTT model and two prominent absorption features near
energies of
9 and 17 keV, that can be interpreted in terms of the cyclotron
absorption line and
its first harmonic (see, DeCesar et al. 2013, ApJ, 762, 61 and recent
NICER measurements
ATel #14457).
We thank NuSTAR team for prompt reaction and help in scheduling of the follow-up observations.
