SVOM detection of two thermonuclear bursts from 4U 1608-52
ATel #17036; M. Brunet (IRAP, France), J.-L. Atteia (IRAP, F), F. Cangemi (APC, F), A. Coleiro (APC, F), N. Dagoneau (CEA, F), O. Godet (IRAP, F), S. Guillot (IRAP, F), Z. Li (XTU, China), J. Rodriguez (CEA, F), L. Tao (IHEP, C), L. Zhang (IHEP, C)
on 13 Feb 2025; 14:42 UT
Credential Certification: Floriane Cangemi (cangemi@apc.in2p3.fr)
Subjects: X-ray, Binary, Neutron Star
Referred to by ATel #: 17037
On Tuesday, February 11th 2025, at 18:49:20 UTC and at 22:05:29 UTC, the SVOM/ECLAIRs (4-150 keV) coded-mask telescope detected two Type I bursts from 4U 1608-52 via an offline search with the event-by-event data downloaded through the X-band ground station.
The lightcurve showed for both bursts a single peak of about 20 s in the 4-20 keV band.
A preliminary spectral analysis of the first burst indicates that the 4-20 keV spectrum, on a time window of 10 s centered on the peak, is well fitted (chi2 = 12.8/9 dof) with a blackbody (bbodyrad) model with a temperature of kT = 2.1+/-0.1 keV (90% confidence level) and a radius of 9.6(+0.7/-0.6) km. The 4-20 keV flux is 5.0(+/-0.2)e-08 erg/s/cm^2 corresponding to a luminosity of about 2.0e38 erg/s, assuming a distance of 5.8 kpc (Guver et al. 2010, ApJ, 712, 964).
Regarding the second burst, a preliminary spectral analysis indicates that the 4-20 keV spectrum, on a time window of 10 s centered on the peak, is well fitted (chi2 = 12.2/8 dof) with a blackbody (bbodyrad) model with a temperature of kT = 2.2+/-0.1 keV and a radius of 9.6(+0.7/-0.6) km. The 4-20 keV flux is 5.5(-0.3/+0.2)e-08 erg/s/cm^2 corresponding to a luminosity of about 2.2e38 erg/s.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES and IRAP. MXT has been developed jointly by CNES, CEA, IJCLab, University of Leicester and MPE.
