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Debris disks as seen by Herschel/DUNES
Magain, P.; Krivov, A. V.; Eiroa, C. +18 more
The far-infrared excesses produced by debris disks are common features of stellar systems. These disks are thought to contain solids ranging from micron-sized dust to planetesimals. Naturally, their formation and evolution are linked to those of potential planets. With this motivation, the Herschel open time key programme DUNES (DUst around NEarby…
CSS091109:035759+102943: A candidate polar
Schwope, A. D.; Thinius, B.
We report optical time-resolved photometry of the CRTS transient CSS091109:035759+102943. Pronounced orbital variability with a 114 min period, large X-ray variability and the IR to X-ray spectral energy distribution suggest a classification as a magnetic cataclysmic binary, a likely AM Herculis star or polar.
Exospheric solar wind charge exchange as seen by XMM-Newton
Read, A. M.; Carter, J. A.; Semba, S.
We review a selection of recent papers describing solar wind charge exchange emission occurring in the Earth's exosphere as seen by the X-ray observatory XMM-Newton. We discuss the detection of this emission, the occurrence with respect to the solar cycle and solar activity, and various spectral signatures observed. We also describe a model develo…
Ion-ion charge exchange and X-rays from the winds of hot stars
Pollock, A. M. T.
Charge exchange occurs between charged ions with enough energy to overcome Coulomb repulsion, a condition satisfied for collisions at velocities like those of the winds driven from hot stars by radiation pressure. X-ray line ratios in some hot stars are inconsistent with those expected from thermal plasmas excited by electron impact. Ion-ion inter…
On the soft X-ray emission of M82
Mao, S.; Wang, Q. D.; Liu, J.
We present a spatial analysis of the soft X-ray and Hα emissions from the outflow of the starburst galaxy M82. We find that the two emissions are tightly correlated on various scales. The O VII triplet of M82, as resolved by X-ray grating observations of XMM-Newton, is dominated by the forbidden line, inconsistent with the thermal prediction. The …
On the surface structure of sunspots
Franz, M.
A precise knowledge of the surface structure of sunspots is essential to construct adequate input models for helioseismic inversion tools. % and to gain information about the subsurface structure of sunspots. We summarize our recent findings about the velocity and magnetic field in and around sunspots using HINODE observation. To this end we quant…
Charge-exchange emission in the starburst galaxies M82 and NGC3256
Ranalli , P.
Charge-exchange (CE) emission produces features which are detectable with the current X-ray instrumentation in the brightest near galaxies. We describe these aspects in the observed X-ray spectra of the star forming galaxies M82 and NGC 3256, from the Suzaku and XMM-Newton telescopes. Emission from both ions (O, C) and neutrals (Mg, Si) is recogni…
Suzaku observations of charge exchange emission from solar system objects
Futaana, Y.; Mitsuda, K.; Porter, F. S. +9 more
Recent results of charge exchange emission from solar system objects observed with the Japanese Suzaku satellite are reviewed. Suzaku is of great importance to investigate diffuse X-ray emission like the charge exchange from planetary exospheres and comets. The Suzaku studies of Earth's exosphere, Martian exosphere, Jupiter's aurorae, and comets a…
Exploring the nature of the brightest hyper-luminous X-ray source
Maccarone, T. J.; Heywood, I.; Farrell, S. A. +7 more
The small subset of hyper-luminous X-ray sources with luminosities in excess of ∼1041 erg s-1 are hard to explain without the presence of an intermediate mass black hole, as significantly super-Eddington accretion and/or very small beaming angles are required. The recent discovery of HLX-1, the most luminous object in this cl…
Unlocking the nature of ultraluminous X-ray sources using their X-ray spectra
Done, C.; Roberts, T. P.; Gladstone, J. C.
We explore the nature of ultraluminous X-ray sources through detailed investigations of their spectral shape using some of the highest quality data available in the XMM-Newton public archives. Phenomenological models allow us to characterise their spectra, while more 'physically-motivated' models enable us to explore the physical processes underly…