Accretion disc coronae and the X-ray source in M15
نویسندگان
چکیده
منابع مشابه
X-ray spectra of accretion discs with dynamic coronae
We compute the X-ray spectra produced by non-static coronae atop accretion discs around black holes and neutron stars. The hot corona is radiatively coupled to the underlying disc (the reflector) and generates an X-ray spectrum which is sensitive to the bulk velocity of the coronal plasma, β = v/c. We show that an outflowing corona reproduces the hard-state spectrum of Cyg X-1 and similar objec...
متن کاملAccretion disc coronae as magnetic reservoirs
Most astrophysical sources powered by accretion onto a black hole, either of stellar mass or supermassive, when observed with hard X-rays show signs of a hot Comptonizing component in the flow, the so-called corona, with observed temperatures and optical depths lying in a narrow range (0.1τ1 and 1×109KT 3×109 K). Here we argue that these facts constitute strong supporting evidence for a magneti...
متن کاملMagnetic Flares and Outflows from Structured Accretion Disc Coronae
We present a model for magnetic structured coronae above accretion discs. On the shortest timescales, spatially and temporally correlated coronal flares can explain Xray temporal and spectral variability observed in Seyfert galaxies. In particular, power density spectra, flux-spectral index and flux-variance correlations are naturally accounted for by the model. More dramatic spectral variation...
متن کاملX-ray Astronomy of Stellar Coronae ⋆
X-ray emission from stars in the cool half of the Hertzsprung-Russell diagram is generally attributed to the presence of a magnetic corona that contains plasma at temperatures exceeding 1 million K. Coronae are ubiquitous among these stars, yet many fundamental mechanisms operating in their magnetic fields still elude an interpretation through a detailed physical description. Stellar X-ray astr...
متن کاملModeling X-ray emission from stellar coronae
By extrapolating from observationally derived surface magnetograms of low-mass stars we construct models of their coronal magnetic fields and compare the 3D field geometry with axial multipoles. AB Dor, which has a radiative core, has a very complex field, whereas V374 Peg, which is completely convective, has a simple dipolar field. We calculate global X-ray emission measures assuming that the ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1987
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/225.1.29p