The X-ray view of black-hole candidate Swift J1842.5-1124 during its 2008 outburst

Abstract

The spectral and temporal evolution during X-ray outbursts give important clues on the accretion process and radiation mechanism in black-hole X-ray binaries (BH XRBs). A set of Swift and RXTE observations were executed to monitor the 2008 outburst of the black-hole candidate Swift J1842.5-1124. We investigate these data to explore the accretion physics in BH XRBs. We carry out a comprehensive spectral and timing analysis on all the available pointing observations, including fitting both X-ray spectra and power density spectra, measuring the optical and near-ultraviolet flux density. We also search for correlations among the spectral and timing parameters. The observed properties of Swift J1842.5-1124 are similar to other BH XRBs in many respects, for example the hardness-intensity diagram and hardness-rms diagram. The type-C quasi-periodic oscillations (QPOs) were observed as the source started to transit from the low-hard state to the high-soft state. The frequency of QPOs correlate with intensity and the hard component index, and anti-correlate with the hardness and the total fractional rms. These relations are consistent with the Lense-Thirring precession model. The estimated U-band flux changed with the X-ray flux, while the flux density at the V band remained 0.26 mJy. These results imply that the X-ray reprocessing or the tail of thermal emission from the outer disk contributes a significant fraction of the U-band radiation; alternatively, the companion star or the jet dominates the flux at longer wavelengths.

6 pages, 5 figures, 3 tables, published in A&A

References in corpus (8)

• X-ray Properties of Black-Hole Binaries
• A Long, Hard Look at the Low-Hard State in Accreting Black Holes
• X-ray irradiation in XTE J1817-330 and the inner radius of the truncated disc in the hard state
• X-ray outbursts of low-mass X-ray binary transients observed in the RXTE era
• A transient low-frequency QPO from the black hole binary GRS 1915+105
• Accretion and ejection in black-hole X-ray transients
• The evolution of the X-ray phase lags during the outbursts of the black hole candidate GX 339-4
• Phase-Resolved Timing Analysis of GRS 1915+105 in Its ρ State

Cited by in corpus (4)

• Inclination effects on the X-ray emission of Galactic black-hole binaries
• Global Accretion Properties of Black Hole X-Ray Binaries: A Phenomenological Perspective
• A Dependable Distance Estimator to Black Hole Low-Mass X-ray Binaries
• MeerKAT radio detection of the Galactic black hole candidate Swift J1842.5-1124 during its 2020 outburst