A New Algorithm for Detecting X-Ray Shots in Cyg X-1

The short-term X-ray variability of Cyg X-1 can be interpreted as a random occurrence of mini-flares known as the shots, whose physical nature is still unclear. We propose a new algorithm for shot identification in the X-ray light curve, based on baseline detection and template fitting. Compared wit...

Full description

Saved in:
Bibliographic Details
Main Authors: Jin Qin, Hua Feng, Lian Tao
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/ada774
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850192250212974592
author Jin Qin
Hua Feng
Lian Tao
author_facet Jin Qin
Hua Feng
Lian Tao
author_sort Jin Qin
collection DOAJ
description The short-term X-ray variability of Cyg X-1 can be interpreted as a random occurrence of mini-flares known as the shots, whose physical nature is still unclear. We propose a new algorithm for shot identification in the X-ray light curve, based on baseline detection and template fitting. Compared with previous techniques, our algorithm allows us to detect shots with lower amplitudes and shorter time separations. With NICER observations, we find that, after correction for detection sensitivity, both the shot amplitude and recurrence rate are positively scaled with the mean count rate, while the recurrence rate has a much higher dependence on the count rate. These suggest that a higher mass accretion rate will drive more and slightly larger shots. We also find that the abrupt hardening near the shot peak found in previous studies is attributed to different shot profiles in different energy bands; there is no need to involve a rapid physical process to suddenly harden the emitting spectrum.
format Article
id doaj-art-147bc7c67b4d4c39af1b38bc30944899
institution OA Journals
issn 1538-4357
language English
publishDate 2025-01-01
publisher IOP Publishing
record_format Article
series The Astrophysical Journal
spelling doaj-art-147bc7c67b4d4c39af1b38bc309448992025-08-20T02:14:38ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198111710.3847/1538-4357/ada774A New Algorithm for Detecting X-Ray Shots in Cyg X-1Jin Qin0Hua Feng1https://orcid.org/0000-0001-7584-6236Lian Tao2https://orcid.org/0000-0002-2705-4338Department of Astronomy, Tsinghua University , Beijing 100084, People’s Republic of ChinaKey Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China ; hfeng@ihep.ac.cnKey Laboratory of Particle Astrophysics, Institute of High Energy Physics , Chinese Academy of Sciences, Beijing 100049, People’s Republic of China ; hfeng@ihep.ac.cnThe short-term X-ray variability of Cyg X-1 can be interpreted as a random occurrence of mini-flares known as the shots, whose physical nature is still unclear. We propose a new algorithm for shot identification in the X-ray light curve, based on baseline detection and template fitting. Compared with previous techniques, our algorithm allows us to detect shots with lower amplitudes and shorter time separations. With NICER observations, we find that, after correction for detection sensitivity, both the shot amplitude and recurrence rate are positively scaled with the mean count rate, while the recurrence rate has a much higher dependence on the count rate. These suggest that a higher mass accretion rate will drive more and slightly larger shots. We also find that the abrupt hardening near the shot peak found in previous studies is attributed to different shot profiles in different energy bands; there is no need to involve a rapid physical process to suddenly harden the emitting spectrum.https://doi.org/10.3847/1538-4357/ada774Stellar mass black holesHigh mass x-ray binary stars
spellingShingle Jin Qin
Hua Feng
Lian Tao
A New Algorithm for Detecting X-Ray Shots in Cyg X-1
The Astrophysical Journal
Stellar mass black holes
High mass x-ray binary stars
title A New Algorithm for Detecting X-Ray Shots in Cyg X-1
title_full A New Algorithm for Detecting X-Ray Shots in Cyg X-1
title_fullStr A New Algorithm for Detecting X-Ray Shots in Cyg X-1
title_full_unstemmed A New Algorithm for Detecting X-Ray Shots in Cyg X-1
title_short A New Algorithm for Detecting X-Ray Shots in Cyg X-1
title_sort new algorithm for detecting x ray shots in cyg x 1
topic Stellar mass black holes
High mass x-ray binary stars
url https://doi.org/10.3847/1538-4357/ada774
work_keys_str_mv AT jinqin anewalgorithmfordetectingxrayshotsincygx1
AT huafeng anewalgorithmfordetectingxrayshotsincygx1
AT liantao anewalgorithmfordetectingxrayshotsincygx1
AT jinqin newalgorithmfordetectingxrayshotsincygx1
AT huafeng newalgorithmfordetectingxrayshotsincygx1
AT liantao newalgorithmfordetectingxrayshotsincygx1