J/ApJ/687/1230 SFXTs observed by Swift. I. Outside outbursts (Sidoli+, 2008)
Monitoring supergiant fast X-ray transients with Swift.
I. Behavior outside outbursts.
Sidoli L., Romano P., Mangano V., Pellizzoni A., Kennea J.A., Cusumano G.,
Vercellone S., Paizis A., Burrows D.N., Gehrels N.
<Astrophys. J., 687, 1230-1235 (2008)>
=2008ApJ...687.1230S 2008ApJ...687.1230S (SIMBAD/NED BibCode)
ADC_Keywords: X-ray sources ; Binaries, X-ray
Keywords: X-rays: individual (AX J1841.0-0536/IGR J18410-0535, IGR J16479-4514,
IGR J17544-2619, XTE J1739-302)
Abstract:
Supergiant fast X-ray transients (SFXTs) are a new class of high-mass
X-ray binaries (HMXBs) discovered thanks to the monitoring of the
Galactic plane performed with the INTEGRAL satellite in the last 5
years. To characterize the properties of these sources on timescales
of months, we are performing a monitoring campaign with Swift of four
SFXTs (IGR J16479-4514, XTE J1739-302, IGR J17544-2619, and AX
J1841.0-0536/IGR J18410-0535). We report on the first 4 months of
Swift observations, which started on 2007 October 26. We detect
low-level X-ray activity in all four SFXTs, which demonstrates that
these transient sources accrete matter even outside their outbursts.
The X-ray spectra are typically hard, with an average 2-10keV
luminosity during this monitoring of about 1033-1034erg/s. We
detected pulsations from the pulsar AX J1841.0-0536/IGR
J18410-0535, with a period of 4.7008±0.0004s.
Description:
The results we are reporting here are concentrated on the
"out-of-outburst" behavior of the four SFXTs monitored with Swift
between 2007 October 26 and 2008 February 28. An old outburst from IGR
J16479-4514 observed in 2005 in archival Swift data is also discussed.
Table 1 reports the log of the Swift observations.
Objects:
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RA (2000) DE Designation(s)
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16 47 59 -45 13.0 IGR J16479-4514 = INTEGRAL1 33
17 54 25.7 -26 19 58 IGR J17544-2619 = 1RXS J175428.3-262035
18 41 00.4 -05 35 46 IGR J18410-0535 = AX J1841.0-0535
17 39 11.6 -30 20 38 XTE J1739-302 = IGR J17391-3021
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 83 66 Observation log
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See also:
V/106 : Catalogue of X-ray binaries (Liu+ 2001)
J/A+A/411/L59 : INTEGRAL reference catalog (Ebisawa+, 2003)
J/A+A/448/L9 : Position catalogue of Swift XRT afterglows (Moretti+, 2006)
J/PAZh/32/508 : Hard X-ray Bursts by INTEGRAL in 2003-2004 (Chelovekov+,
2006)
J/A+A/523/A61 : INTEGRAL all-sky survey of hard X-ray sources (Krivonos+,
2010)
J/MNRAS/397/1177 : Swift-XRT rlts of GRBs (Evans+, 2009)
J/ApJS/186/378 : Hard X-ray survey from Swift-BAT 2004-2006 (Tueller+, 2010)
http://www.swift.psu.edu/xrt : Swift X-Ray Telescope (XRT) home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Name Source name (IGR or XTE)
17- 27 A11 --- Seq Swift sequence identification (1)
29 A1 --- n_Seq [Bcd] observation origin (2)
31- 37 A7 --- Mode Swift Instrument/Mode configuration
39- 48 A10 "YYYY/MM/DD" beg.date Start UT date
50- 57 A8 "h:m:s" beg.time Start UT time
59- 68 A10 "YYYY/MM/DD" end.date End UT date
70- 77 A8 "h:m:s" end.time End UT time
79- 83 I5 s Exp ? Net exposure time (3)
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Note (1): Archival data unless noted.
Note (2): Flag as follows:
B = new observation;
c = the source triggered Swift/BAT;
d = the source was detected with the Swift/BAT hard X-ray transient monitor.
Note (3): The exposure time is spread over several snapshots (single continuous
pointings at the target) during each observation.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 12-Jan-2011