A Cyclic Burst Rate Behavior of a Persistent X-ray Burster: Recent XMM-Newton and NuSTAR Observations of 4U 1323-62
Tugba Boztepe, Tolga Guver, Ersin Gogus, Diego Altamirano, Julia Speicher, Brian Luff, David R. Ballantyne
arXiv:2605.11121v1 Announce Type: new
Abstract: In this study, we report partly simultaneous XMM-Newton and NuSTAR observations of the bursting, dipping low mass X-ray binary, 4U 1323-62 obtained in 2024. 4U 1323-62 is one of the well-known persistent bursters, with bursts occurring roughly every three hours. It is also one of the few sources for which the orbital period is known, and shows dips in X-rays. In this paper, we report the detection of 12 unique bursts with XMM-Newton and NuSTAR, 6 of them observed jointly. We detected two double burst events, one with the NuSTAR and another one observed with both missions. Based on the long-term behavior of 4U 1323-62, we unveil a cyclic trend in its burst rate, with a period of about 10 years. During our observations we detected 10 X-ray dips with a periodicity of 2.942 hours, in line with previous measurements. We also present the results of the time resolved X-ray spectral analysis of the bursts and show the limits on the cooling of the corona heated by the burst emission. We also found a 0.898 +/- 0.017 Hz quasi-periodic oscillation (QPO) during the non-bursting and non-dipping times confirming previous detections.arXiv:2605.11121v1 Announce Type: new
Abstract: In this study, we report partly simultaneous XMM-Newton and NuSTAR observations of the bursting, dipping low mass X-ray binary, 4U 1323-62 obtained in 2024. 4U 1323-62 is one of the well-known persistent bursters, with bursts occurring roughly every three hours. It is also one of the few sources for which the orbital period is known, and shows dips in X-rays. In this paper, we report the detection of 12 unique bursts with XMM-Newton and NuSTAR, 6 of them observed jointly. We detected two double burst events, one with the NuSTAR and another one observed with both missions. Based on the long-term behavior of 4U 1323-62, we unveil a cyclic trend in its burst rate, with a period of about 10 years. During our observations we detected 10 X-ray dips with a periodicity of 2.942 hours, in line with previous measurements. We also present the results of the time resolved X-ray spectral analysis of the bursts and show the limits on the cooling of the corona heated by the burst emission. We also found a 0.898 +/- 0.017 Hz quasi-periodic oscillation (QPO) during the non-bursting and non-dipping times confirming previous detections.