INTEGRAL detects a new outburst from the Be/X-ray binary SXP6.85 in the Small Magellanic Cloud
ATel #7481; M. Nikolajuk (Univ. of Bialystok, Poland), E. Bozzo, C. Ferrigno (ISDC, Switzerland)
on 7 May 2015; 07:45 UT
Credential Certification: Carlo Ferrigno (Carlo.Ferrigno@unige.ch)
Subjects: X-ray, Neutron Star, Transient, Pulsar
During the observations performed in the direction of the Small Magellanic Cloud from 2015 April 29 at 04:37 to April 30 at 12:24 and from 2015 May 4 at 12:33 to May 5 at 20:15 (UTC), the IBIS/ISGRI and the two JEM-X instruments on-board INTEGRAL detected a new outburst from the Be/X-ray binary pulsar SXP6.85 (Townsend et al. 2010, MNRAS, 403, 1239).
In the combined IBIS/ISGRI mosaic, the source is detected at 12σ significance level and at an average flux of 5.1±0.5 mCrab in the 20-40 keV energy band (total exposure time 214 ks). The average source flux estimated from the corresponding JEM-X mosaic was 2.3±0.6 mCrab in the 3-10 keV energy band.
The average ISGRI and JEM-X spectra (effective exposure time 150 ks) could be well fit (χ2red/d.o.f.=0.8/9) by using a power-law model with a photon index of 2.1±0.2. The 5-40 keV flux estimated from the spectral fit was 1.1×10-10 erg/cm2/s.
The source has been observed to decay in flux from 2015 April 29 to 2015 May 5 from 9.4±0.05 mCrab to 3.2±0.6 mCrab in the 20-40 keV energy band. Further INTEGRAL observations in the direction of the SMC have been already planned for 2015 May 15.