Related papers: Soft coronal X-rays from \beta{} Pictoris

A growing number of early Be stars discovered in X-ray surveys exhibit X-ray luminosities intermediate between those of normal stars and those of most Be/X-ray binaries in quiescence. Their X-ray spectra are also much harder than those of…

- Aims: Gas cooling in the centre of massive galaxy clusters is believed to feed the most powerful active galactic nuclei in the Universe. How often clusters at high redshift show such cool cores has still to be explored by current and…

We report the detection of N V 1239 A transition region emission in HST/GHRS spectra of the A7 V stars, Alpha Aql and Alpha Cep. Our observations provide the first direct evidence of 1-3 x 10^5 K material in the atmospheres of normal A-type…

We present a Chandra X-ray observation that shows, unambiguously for the first time, the presence of a giant diffuse X-ray-emitting corona around the edge-on disk galaxy NGC 4631. This corona, with a characteristic thermal temperature of…

The X-ray spectra of many active galactic nuclei (AGN) show a soft X-ray excess below 1-2 keV on top of the extrapolated high- energy power law. The origin of this component is uncertain. It could be a signature of relativistically blurred,…

We present the X-ray analysis of coronal properties in a statistically representative sample of 23 mostly radio-quiet AGN from the SUBWAYS campaign (SUpermassive Black holes Winds in XrAYs), focusing on quasars at redshifts $0.1 < z < 0.4 $…

The corona is an integral component of Active Galactic Nuclei (AGN) which produces the bulk of the X-ray emission above 1--2 keV. However, many of its physical properties and the mechanisms powering this emission remain a mystery. In…

We report a detection (3.5x10^37 \pm 5.6x10^36 ergps) of the optical coronal emission line [Fe X]6374 and upper limits of four other coronal lines using high resolution VIMOS spectra centred on NGC 4696, the brightest cluster galaxy in the…

Less than half of the SNRs within 5 kpc have identified central sources, and only three are identified as the remnants of Type Ia SNe. Here, we report a systematic effort to search for compact central sources in the remaining 23 SNRs of…

We investigate the levels of small scale structure in surface brightness images of the core of the X-ray bright cool-core galaxy cluster AWM 7. After subtraction of a model of the smooth cluster emission, we find a number of approximately…

We present the results of soft X-ray studies of the classical nova V2491 Cygni using the Suzaku observatory. On day 29 after outburst, a soft X-ray component with a peak at ~0.5 keV has appeared, which is tantalising evidence for the…

We present a systematical analysis of the Chandra observations of 53 nearby highly-inclined (i>60 degree) disk galaxies to study the coronae around them. This sample covers a broad range of galaxy properties: e.g., about three orders of…

A recent re-analysis of Einstein data, and new ROSAT observations, have revealed the presence of at least two components in the X-ray spectra of X-ray faint early-type galaxies: a relatively hard component (kT>1.5 keV), and a very soft…

Chandra X-ray and HST far-ultraviolet (FUV) observations of three early-F supergiants have shed new light on a previous puzzle involving a prominent member of the class: Alpha Persei (HD20902: F5Ib). The warm supergiant is a moderately…

We report the first Chandra detection of emission out to the virial radius in the cluster Abell 1835 at z=0.253. Our analysis of the soft X-ray surface brightness shows that emission is present out to a radial distance of 10 arcmin or 2.4…

Abell~1142 is a low-mass galaxy cluster at low redshift containing two comparable Brightest Cluster Galaxies (BCG) resembling a scaled-down version of the Coma Cluster. Our Chandra analysis reveals an X-ray emission peak, roughly 100 kpc…

Alpha Centauri A is the closest solar-type star to the Sun and offers an excellent opportunity to detect the thermal emission of a mature planet heated by its host star. The MIRI coronagraph on JWST can search the 1-3 AU (1"-2") region…

Relativistic jets around supermassive black holes (SMBHs) are well-known powerful $\gamma$-ray emitters. In absence of the jets in radio-quiet active galactic nuclei (AGNs), how the SMBHs work in $\gamma$-ray bands is still unknown despite…

We present BeppoSAX observations of the Seyfert 1.8 galaxy NGC1365 in the 0.1--100 keV range. The source was 6 times brighter than during an ASCA observation 3 years earlier. The 4--10 keV flux is highly variable during the BeppoSAX…

X-ray spectra of groups of galaxies, obtained with the GIS instrument onboard ASCA, were investigated for diffuse hard X-rays in excess of the soft thermal emission from their inter-galactic medium (IGM). In total, 18 objects with the IGM…