TY - JOUR
T1 - A Comparison of Neutron Star Blackbody Luminosities in LMXB with the Theory of Accretion Flow Spreading on the Stellar Surface
AU - Church, Michael
AU - Inogamov, M
AU - Balucinska-Church, Monika
PY - 2002/7/1
Y1 - 2002/7/1
N2 - We present a comparison of the results of the ASCA survey of LMXB with the Inogamov & Sunyaev theory of accretion flow spreading on the surface of neutron stars. The ASCA survey of LMXB of Church & Balucinska-Church (2001) revealed a systematic variation of the luminosity of blackbody emission from the neutron star spanning 3 decades in total X-ray luminosity suggesting that the level of blackbody emission is controlled by the physics of the inner disk/stellar interface, which we can hope to understand. Two types of explanation exist: firstly that there is radial flow between the inner disk and star at all vertical positions above the orbital plane so that the height of the disk directly determines the area of star emitting. Secondly, the height of the emitting region on the star is not directly related to the disk properties but depends on the mass accretion rate as suggested by Inogamov & Sunyaev (1999) in their theory of accretion flow spreading on the stellar surface. We find that the survey results for the emitting area agree with this theory at the lowest luminosities. However, for higher luminosities, the blackbody emission is stronger than predicted by spreading theory suggesting that the emitting area is controlled by radial flow between disk and star.
AB - We present a comparison of the results of the ASCA survey of LMXB with the Inogamov & Sunyaev theory of accretion flow spreading on the surface of neutron stars. The ASCA survey of LMXB of Church & Balucinska-Church (2001) revealed a systematic variation of the luminosity of blackbody emission from the neutron star spanning 3 decades in total X-ray luminosity suggesting that the level of blackbody emission is controlled by the physics of the inner disk/stellar interface, which we can hope to understand. Two types of explanation exist: firstly that there is radial flow between the inner disk and star at all vertical positions above the orbital plane so that the height of the disk directly determines the area of star emitting. Secondly, the height of the emitting region on the star is not directly related to the disk properties but depends on the mass accretion rate as suggested by Inogamov & Sunyaev (1999) in their theory of accretion flow spreading on the stellar surface. We find that the survey results for the emitting area agree with this theory at the lowest luminosities. However, for higher luminosities, the blackbody emission is stronger than predicted by spreading theory suggesting that the emitting area is controlled by radial flow between disk and star.
KW - accretion, accretion disks
KW - binaries : close
KW - X rays : stars
KW - stars : neutron
UR - http://www.scopus.com/inward/record.url?scp=0036647926&partnerID=8YFLogxK
U2 - 10.1051/0004-6361:20020678
DO - 10.1051/0004-6361:20020678
M3 - Article
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
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SN - 1432-0756
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SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
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SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
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SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
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SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
SN - 1432-0756
VL - 390
SP - 139
EP - 146
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 1
ER -