2,362 research outputs found
Possible hard X-ray shortages in bursts from KS 1731-260 and 4U 1705-44
Aims: A hard X-ray shortage, implying the cooling of the corona, was observed
during bursts of IGR J17473-272, 4U 1636-536, Aql X-1, and GS 1826-238. Apart
from these four sources, we investigate here an atoll sample, in which the
number of bursts for each source is larger than 5, to explore the possible
additional hard X-ray shortage during {\it Rossi X-ray timing explorer (RXTE)}
era. Methods: According to the source catalog that shows type-I bursts, we
analyzed all the available pointing observations of these sources carried out
by the {\it RXTE} proportional counter array (PCA). We grouped and combined the
bursts according to their outburst states and searched for the possible hard
X-ray shortage while bursting. Results: We found that the island states of KS
1731-260 and 4U 1705-44 show a hard X-ray shortage at significant levels of 4.5
and 4.7 and a systematic time lag of s and
s with respect to the soft X-rays, respectively. While in their banana branches
and other sources, we did not find any consistent shortage.Comment: 5 pages, 4 figures, accepted by A&A as a research not
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