On the Amplitude of Burst Oscillations in 4U 1636−54: Evidence for Nuclear-powered Pulsars
Author(s) -
Tod E. Strohmayer,
William Zhang,
J. H. Swank,
N. E. White,
Iosif Lapidus
Publication year - 1998
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/311322
Subject(s) - neutron star , physics , amplitude , astrophysics , millisecond pulsar , pulsar , oscillation (cell signaling) , thermonuclear fusion , millisecond , radius , pulse (music) , bursting , x ray binary , astronomy , plasma , nuclear physics , optics , computer security , neuroscience , detector , biology , computer science , genetics
We present a study of 581 Hz oscillations observed during a thermonuclearX-ray burst from the low mass X-ray binary (LMXB) 4U 1636-54 with the RossiX-ray Timing Explorer (RXTE). We argue that the combination of large pulsedamplitudes near burst onset and the spectral evidence for localized emissionduring the rise strongly supports rotational modulation as the mechanism forthe oscillations. We discuss how theoretical interpretation of spin modulationamplitudes, pulse profiles and pulse phase spectroscopy can provide constraintson the masses and radii of neutron stars. We also discuss the implication ofthese findings for the beat frequency models of kHz X-ray variability in LMXB.Comment: AASTEX Latex, 13 pages including 5 figures. Accepted for publication in the Astrophysical Journal Letter
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