We report the observations of X-ray oscillations during the flare in a cool active star ξ Boo for the first time. ξ Boo was observed by EPIC/MOS of XMM-Newton satellite. The X-ray light curve is investigated with wavelet and periodogram analyses. Both analyses clearly show oscillations of the period of ∼ 1019 s. We interpret these oscillations as a fundamental fast-kink mode of magnetoacoustic ...

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...

We present new spectroscopic observations of the He I λ10830 line in R Coronae Borealis (RCB) stars which provide the first strong evidence that most, if not all, RCB stars have winds. It has long been suggested that when dust forms around an RCB star, radiation pressure accelerates the dust away from the star, dragging the gas along with it. The new spectra show that nine of the ten stars obse...

In the current issue of ACS Nano, Löbling, Haataja et al. craft polymeric nanoparticles with a hierarchy of nontrivial surface structures by combining conventional interpolyelectrolyte complexation with steric control from an uncharged copolymer block. Remarkable cylindrical and lamellar nanodomains are produced on the polyionic coronae of spherical micelles. Here, we discuss generalizing this ...

Cold optically thick accretion disks with hot coronae and radial advection have been investigated. Within the framework of -viscosity models, we assume that all the mass accretion and angular momentum transport take place in the cold disk, but that a fraction of the gravitational energy released is dissipated in the corona. Both the coronal energy dissipation and the advection heat transport ha...

We point out that a conventional construction placed upon observations of accreting black holes, in which their nonthermal X-ray spectra are produced by inverse comptonization in a coronal plasma, suggests that the plasma is marginally collisionless. Recent developments in plasma physics indicate that fast reconnection takes place only in collisionless plasmas. As has recently been suggested fo...

We present a new model for the coronal structure of rapidly rotating solar-type stars. The presence of prominences trapped in co-rotation 2 to 5 stellar radii above the stellar surface has been taken as evidence that the coronae of these stars must be very extended. The observed surface magnetic fields, however, cannot contain Xray emitting gas out to these distances. We present an alternative ...

Let X be a (connected and reduced) complex space. A qcollar of X is a bounded domain whose boundary is a union of a strongly q-pseudoconvex, a strongly q-pseudoncave and two flat (i.e. locally zero sets of pluriharmonic functions) hypersurfaces. Finiteness and vanishing cohomology theorems obtained in [17], [18] for semi q-coronae are generalized in this context and lead to results on extension...