[ Previous | Next | ADS ]

Three transient X-ray sources during the INTEGRAL revolution 1710

ATel #9356; M. Fiocchi (IAPS/INAF, Italy), A. Bazzano (IAPS/INAF, Italy), A. J. Bird (Univ. of Southampton, UK), Phil Charles (Univ. of Southampton, UK), J. Chenevez (DTU Space, Denmark), P. Ubertini (IAPS/INAF, Italy) and on behalf of the INTEGRAL/GPS team.
on 9 Aug 2016; 20:44 UT
Credential Certification: mariateresa fiocchi (mariateresa.fiocchi@iaps.inaf.it)

Subjects: X-ray, Gamma Ray, Binary, Black Hole, Neutron Star, Transient

During recent INTEGRAL observations of the Musca and Norma regions (revolutions 1710) performed between 2016-08-05 16:00:36 UTC and 2016-08-07 21:02:14 UTC a renewed activity from the following transient X-ray sources has been detected:
1) IGR J17091-3624, a remarkable transient black hole LMXB
2) XTE J1701-407, a transient neutron star LMXB
3) H 1608-522, a known LMXB, Burst and Atoll source
We report on the fluxes and exposure times of their IBIS/ISGRI and JEM-X1+JEM-X2 detections during the INTEGRAL revolution 1710:

Source Flux(18-40 keV) Exposure Flux(40-100keV) Exposure Flux(3-10 keV) F(10-25 keV) Exposure
mCrab ks mCrab ks mCrab mCrab ks
IGR J17091-3624 22.2+/-1.0 11 28.4+/-1.5 18 4.1 +/-2.6 (<3 sigma) 14.3
XTE J1701-407 10.2+/-0.7 17 <3.5 (3 sigma) 28 5.2 +/-1.5 (<3 sigma) 33
H 1608-522 11.9+/-0.7 16 <3.5 (3 sigma) 28 272.2 +/-1.4 70.4 +/-2.5 33.7

IGR J17091-3624 was also detected during the revolution 1709 (start 2016-08-04T01:11 UTC; stop 2016-08-05 05:05:40) with a flux of 20.5+/-1.0 mCrab (18-40 keV) and 14.2+/-0.7 mCrab (40-100 keV) for effective on-source exposure time of 10 ks and 18 ks, respectively. The JEM-X1 exposure time is 7.1 ks with an emission lower than 3 sigma in 3-10 keV and a flux of 24+/-8 mCrab in 10-25 keV energy range.
During the revolution 1709 XTE J1701-407 was within the field of view of JEM-X1 instrument for a net exposure time of 20.2 ks and it was detected at a flux level of 7.4+/-2.1 mCrab and 15.5+/-4.0 mCrab in the 3-10 keV and 10-25 keV, respectively.
We note that the source H 1608-522 was also detected on 2016 August 5 by MAXI (ATel #9330) and during the previous INTEGRAL revolution 1708 (observation start 2016-07-31T10:46 UTC; stop 2016-08-02 02:21:04 UTC) showing hard X-ray emission with 18-40 keV and 40-100 keV fluxes of 10.2+/-1.0 mCrab and 9.1+/-1.6 mCrab, for effective on-source exposure times of 8 ks and 14 ks, respectively.