Related papers: Spatial identification of the overionized plasma i…
The region towards W51C is a convincing example of interaction between a supernova remnant and a surrounding molecular cloud. Large electron abundances have been reported towards the position W51C-E located in this interaction region, and…
We investigate models for the photoionization of the widespread diffuse ionized gas in galaxies. In particular we address the long standing question of the penetration of Lyman continuum photons from sources close to the galactic midplane…
The fast shocks that characterize supernova remnants heat circumstellar and ejecta material to extremely high temperatures, resulting in significant X-ray emission. The X-ray spectrum from an SNR carries a wealth of information about the…
We have studied the X-ray emission within the inner 150 pc radius of NGC 4151 by constructing high spatial resolution emission line images of OVII, OVIII, and NeIX. These maps show extended structures that are spatially correlated with the…
We report on NuSTAR observations of the mixed morphology supernova remnant (SNR) W49B, focusing on its nonthermal emission. Whereas radio observations as well as recent gamma-ray observations evidenced particle acceleration in this SNR,…
We have performed a deep Chandra observation of Galactic Type Ia supernova remnant G299.2-2.9. Here we report the initial results from our imaging and spectral analysis. The observed abundance ratios of the central ejecta are in good…
Cosmic rays pervade the Galaxy and are thought to be accelerated in supernova shocks. The interaction of cosmic rays with dense interstellar matter has two important effects: 1) high energy (>1 GeV) protons produce {\gamma}-rays by…
Using our deep ~120 ks Chandra observation, we report on the results from our spatially-resolved X-ray spectral analysis of the "oxygen-rich" supernova remnant (SNR) 0540-69.3 in the Large Magellanic Cloud. We conclusively establish the…
High ionisation lines in the soft X-ray band are generally associated to either interstellar hot gas along the line of sight or to photoionised gas intrinsic to the source. In the low-mass X-ray binary 4U 1820-30, the nature of these lines…
We present new Jansky Very Large Array (VLA) images of the central region of the W49A star-forming region at 3.6~cm and at 7~mm at resolutions of 0\farcs15 (1650 au) and 0\farcs04 (440 au), respectively. The 3.6~cm data reveal new…
We report the serendipitous discovery of a transient X-ray source, Suzaku J1305$-$4930, $\sim$3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku…
SS 433, located at the center of the W 50 radio nebula, is a binary system that ejects jets oriented east-west with precessional motion. X-ray lobes, containing compact "knots" labeled as head (e1), lenticular (e2), and ring (e3) in the…
The plasma opacity in stars depends mainly on the local state of matter (the density, temperature, and chemical composition at the point of interest), but in supernova ejecta it also depends on the expansion velocity gradient, because the…
Diffusive shock acceleration by the shockwaves in supernova remnants (SNRs) is widely accepted as the dominant source for Galactic cosmic rays. However, it is unknown what determines the maximum energy of accelerated particles. The…
Supernova remnant (SNR) detection along the Galactic plane poses a number of challenges. The SNR G309.8+00.0 lies exactly on the Galactic plane, with its center coinciding with galactic latitude (b)=0 deg. In this paper we report the first…
We present mid-infrared (5-40 micron) spectra of shocked ejecta in the Galactic oxygen-rich supernova remnant G292.0+1.8, acquired with the IRS spectrograph on board the Spitzer Space Telescope. The observations targeted two positions…
Five on-plane regions within +/- 0.8deg of the Galactic center were observed with the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS) onboard Suzaku. From all regions, significant hard X-ray emission was detected with…
Low mass X-ray binaries exhibit ionized emission from an extended disk atmosphere that surrounds the accretion disk. However, its nature and geometry is still unclear. In this work we present a spectral analysis of the extended atmosphere…
Although about 40% of the soft X-ray background emission in 0.4 to 1 keV range has extragalactic origins and thus is totally blocked by the Galactic absorption in midplane directions, it decreases at most by about 20 % in midplane. Suzaku…
We suggest an additional possible plasma source to explain part of the phenomena observed for the transiting hot Jupiters WASP-12b and HD 189733b in their ultraviolet (UV) light curves. In the proposed scenario, material outgasses from the…