| Autor: |
Pahari, Mayukh, Suman, Shree, Bhargava, Yash, Weston, Alexander, Zhang, Liang, Bhattacharyya, Sudip, Misra, Ranjeev, McHardy, Ian |
| Předmět: |
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| Zdroj: |
Monthly Notices of the Royal Astronomical Society; Mar2024, Vol. 528 Issue 3, p4125-4138, 14p |
| Abstrakt: |
The timing properties of the Z-type low-mass X-ray binaries provide insights into the emission components involved in producing the unique Z-shaped track in the hardness–intensity diagrams of these sources. In this work, we investigate the AstroSat and NICER observations of the GX 340 + 0 covering the complete 'Z'-track from the horizontal branch (HB) to the extended flaring branch (EFB). For the first time, we present the Z-track as seen in soft X-rays using the AstroSat / Soft X-ray Telescope and NICER (the soft colour is defined as a ratio of 3–6 to 0.5–3 keV). The shape of the track is distinctly different in soft X-rays, strongly suggesting the presence of additional components active in soft X-rays. The detailed timing analysis revealed significant quasi-periodic oscillation throughout the HB and the normal branch (NB) using large area X-ray proportional counter and the first NICER detection of 33.1 ± 1.1 Hz HB oscillation (HBO) in 3–6 keV. The oscillations at the HB/NB vertex are observed to have higher frequencies (41–52 Hz) than the HBOs (16–31 Hz) and NB oscillations (6.2–8 Hz) but significantly lower rms (∼1.6 per cent). The HBO is also limited to the energy range 3–20 keV, indicating an association of HBO origin with the non-thermal component. It is also supported by earlier studies that found the strongest X-ray polarization during HB. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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