X-ray Timing and Spectral Behavior of the Rapid Burster

Abstract

We present an X-ray fast-timing and spectral analysis of the type II bursts and the persistent emission (PE) of the Rapid Burster observed with the EXOSAT Medium-Energy Instrument. The Hardness-Intensity and Color-Color Diagrams of the Rapid Burster are somewhat different from those of the majority of other low-mass X-ray binaries, which fall into two distinct groups, ``atoll'' and ``Z'' sources. The strength and frequencies of quasi-periodic oscillations (QPO) in the bursts and the PE, as well as a strong anti-correlation between QPO frequency and burst peak flux, also distinguish the Rapid Burster from atoll and Z sources. The presence, frequency, and strength of QPO in type II bursts are all correlated in some manner to the spectral hardness, as are the strength of QPO and the very low-frequency noise (VLFN) component in the persistent emission.

52 pages, including 20 figures, LaTeX; complete Postscript file available from http://space.mit.edu/home/rutledge/Welcome.html ; MNRAS in press

Cited by in corpus (6)

• 1 Hz flaring in SAX J1808.4--3658: flow instabilities near the propeller stage
• The Evolution of Rapid Burster Outbursts
• A population study of type II bursts in the Rapid Burster
• Study of the X-ray properties of the neutron-star binary 4U 1728$-$34 from the soft to hard state
• Double-peaked thermonuclear bursts at the soft-hard state transition in the Rapid Burster
• Possible Analogues of Cognitive Processes in the Patterns of X-ray Variability of the Rapid Burster