In:
Publications of the Astronomical Society of Japan, Oxford University Press (OUP), Vol. 74, No. 4 ( 2022-08-04), p. 974-990
Abstract:
We investigate the decades-long X-ray variations in bright low-mass X-ray binaries containing a neutron star (NS-LMXBs). The light curves of MAXI/GSC and RXTE/ASM cover ∼26 yr, and high-quality X-ray light curves are obtained from 33 NS-LMXBs. Among these, together with Ginga/ASM, two sources (GX 3+1 and GX 9+1) showed an apparent sinusoidal variation with respective periods of ∼5 and ∼10 yr in the 34 yr light curve. Their X-ray luminosities were (1–4) × 1037 erg s−1 in the middle of the NS-LMXB luminosity distribution. Seven other sources (Ser X-1, 4U 1735−444, GX 9+9, 4U 1746−37, 4U 1708−40, 4U 1822−000, and 1A 1246−588) have similar sinusoidal variations, although the profiles (amplitude, period, and phase) are variable. Compering the 21 sources with known orbital periods, one possible cause of the long-term sinusoidal variation might be mass-transfer cycles induced by irradiation to the donor star.
Type of Medium:
Online Resource
ISSN:
0004-6264
,
2053-051X
DOI:
10.1093/pasj/psac049
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2022
detail.hit.zdb_id:
2206640-8
detail.hit.zdb_id:
2083084-1
SSG:
16,12
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