INTEGRAL observations of the variability of OAO 1657-415
نویسندگان
چکیده
منابع مشابه
INTEGRAL observations of OAO 1657−415: gamma-ray tomography of a B supergiant
OAO 1657−415 is an accreting pulsar in an eclipsing binary system. We analyzed the INTEGRAL core program observations of this object and obtained the eclipse light curve in the soft gamma-ray band between 15 and 40 keV. We note that the gamma rays from the pulsar allow to probe the density profile of the outer layers of the B supergiant companion. We find that the density profile of the outer l...
متن کاملASCA Observations of OAO 1657−415 and its Dust-Scattered X-Ray Halo
We report on two ASCA observations of the high-mass X-ray binary pulsar OAO 1657−415. A short observation near mid-eclipse caught the source in a lowintensity state, with a weak continuum and iron emission dominated by the 6.4-keV fluorescent line. A later, longer observation found the source in a high-intensity state and covered the uneclipsed through mid-eclipse phases. In the high-intensity ...
متن کاملOAO 1657 – 415 : A ‘ Missing Link ’ in High Mass X - ray Binaries ?
OAO1657–415 is only the seventh eclipsing X-ray pulsar known and therefore has the potential to yield only the seventh mass of a neutron star in an X-ray binary. Here we report photometric and spectroscopic observations of candidates for the optical counterpart to the system and identify a B5III or B6V star as a possible companion to the neutron star. We measure the observational parameters of ...
متن کاملSpectral classification of the mass donors in the high - mass X - ray binaries EXO 1722 - 363 and OAO 1657 - 415 . ⋆
Aims. We report near-infrared (NIR) observations of the mass donors of the eclipsing high-mass X-ray binary (HMXB) systems EXO 1722-363 and OAO 1657-415 in order to derive their accurate spectral classifications. Methods. ESO/VLT observations of the targets with the NIR spectrometer ISAAC were compared with several published NIR spectral atlases of O and B supergiants, an identification of each...
متن کاملexistence and approximate $l^{p}$ and continuous solution of nonlinear integral equations of the hammerstein and volterra types
بسیاری از پدیده ها در جهان ما اساساً غیرخطی هستند، و توسط معادلات غیرخطی بیان شده اند. از آنجا که ظهور کامپیوترهای رقمی با عملکرد بالا، حل مسایل خطی را آسان تر می کند. با این حال، به طور کلی به دست آوردن جوابهای دقیق از مسایل غیرخطی دشوار است. روش عددی، به طور کلی محاسبه پیچیده مسایل غیرخطی را اداره می کند. با این حال، دادن نقاط به یک منحنی و به دست آوردن منحنی کامل که اغلب پرهزینه و ...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2008
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20078707