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Record 1 of 6979
Discovery of Eclipses from the Accreting Millisecond X-Ray Pulsar Swift J1749.4-2807
External Online Source: doi:10.1088/2041-8205/717/2/L149
Author and Affiliation:
Markwardt, C. B.(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Stromhmayer, T. E.(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Abstract: We report the discovery of X-ray eclipses in the recently discovered accreting millisecond X-ray pulsar SWIFT J1749.4-2807. This is the first detection of X-ray eclipses in a system of this type and should enable a precise neutron star mass measurement once the companion star is identified and studied. We present a combined pulse and eclipse timing solution that enables tight constraints on the orbital parameters and inclination and shows that the companion mass is in the range 0.6-0.8 solar mass for a likely range of neutron star masses, and that it is larger than a main-sequence star of the same mass. We observed two individual eclipse egresses and a single ingress. Our timing model shows that the eclipse features are symmetric about the time of 90 longitude from the ascending node, as expected. Our eclipse timing solution gives an eclipse duration (from the mid-points of ingress to egress) of 2172+/-13 s. This represents 6.85% of the 8.82 hr orbital period. This system also presents a potential measurement of "Shapiro" delay due to general relativity; through this technique alone, we set an upper limit to the companion mass of 2.2 Solar mass .
Publication Date: Jul 10, 2010
Document ID:
20110015316
(Acquired Sep 13, 2011)
Subject Category: ASTROPHYSICS
Report/Patent Number: GSFC.JA.4834.2011
Document Type: Journal Article
Publication Information: The Astrophysical Journal - Letters; p. L149-L153; Volume 717; No. 2
Publisher Information: American Astronomical Society, United States
Financial Sponsor: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Organization Source: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Description: 6p; In English; Original contains black and white illustrations
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: PULSARS; COMPANION STARS; MAIN SEQUENCE STARS; NEUTRON STARS; ECLIPSES; EGRESS; STELLAR MASS; X RAYS; RELATIVITY; NEUTRONS; LONGITUDE
Availability Source: Other Sources
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Last Modified: September 13, 2011
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