A Minimal Time Scale for the Spectral States of GX 339-4

Abstract

Black hole transients are known to undergo spectral transitions that form q-shaped tracks on a hardness intensity diagram. In this work, we use archival RXTE data to extract a characteristic minimal timescale for the spectral states in GX 339-4 for the 2002-3, and 2010 outbursts. We use the extracted timescale to construct an intensity variability diagram for each outburst. This new diagram is comparable to the traditional hardness intensity diagram and offers the potential for probing the underlying dynamics associated with the evolution of the relevant emission regions in black hole transients. We confirm this possibility by connecting the minimal timescale with the inner disk radius, $R_{in}$ (estimated from spectral fits), and demonstrate a positive correlation between these variables as the system evolves through its spectral transitions. Furthermore, we probe the relation between the minimal timescale and the break frequencies extracted from the power spectral densities. Lastly, we examine a possible link between the extracted timescale and a traditional measure of variability i.e., the root mean square, determined directly from the power spectra.

Accepted for publication in MNRAS

References in corpus (5)

• X-ray Properties of Black-Hole Binaries
• Modelling the behaviour of accretion flows in X-ray binaries
• Revealing accretion onto black holes: X-ray reflection throughout three outbursts of GX 339-4
• Evolution of the reverberation lag in GX 339-4 at the end of an outburst
• Thermal emission from the stellar-mass black hole binary XTE J1118+480 in the low/hard state

Cited by in corpus (2)

• A Minimal Timescale for the Continuum in 4U 1608-52 and Aql X-1
• A Temporal Scale to Track the Spectral Transitions in Low-Mass X-ray Binaries