Related papers: Hot dust in two hard Chandra X-ray sources

We present the first X-ray detection of resonant absorption from warm/hot local gas either in our Galaxy, or in the Intergalactic space surrounding our Galaxy, along the line of sight toward the blazar PKS 2155-304. The Chandra HRCS-LETG…

We present results from a 38 ks Chandra X-ray observation of the z=0.059 galaxy cluster A1991. The cluster has a bright X-ray core and a central temperature gradient that declines inward from 2.7 keV at 130 kpc to approximately 1.6 keV at…

We present evidence of the co-existence of either an AGN or an ultraluminous X-ray source (ULX), together with a young super stellar cluster in the 3 central parsecs of NGC4303. The galaxy contains a low luminosity AGN and hosts a number of…

VLT J- to M\p-band adaptive optics observations of the Circinus Galaxy on parsec scales resolve a central bright Ks-band source with a FWHM size of 1.9 $\pm$ 0.6 pc. This source is only visible at wavelengths longward of 1.6 $\mu$m and…

The relatively nearby (distance=24.1 Mpc) elliptical galaxy NGC821, hosting a central massive black hole but inactive at all wavelengths, was observed with Chandra for a total exposure of 230 ksec, to search for nuclear emission and gas…

We present a detailed X-ray spectral analysis of 1152 AGNs selected in the Chandra Deep Fields (CDFs), in order to identify highly obscured AGNs ($N_{\rm H} > 10^{23}\ \rm cm^{-2}$). By fitting spectra with physical models, 436 (38%)…

We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…

Infrared carbon stars without visible counterparts are generally known as extreme carbon stars. We have selected a subset of these stars with absorption features in the 10-13 $\mu$m range, which has been tentatively attributed to silicon…

The first systematic study of the serendipitous X-ray source density around 10 high z (0.24<z<1.2) clusters has been performed with Chandra. A factor ~2 overdensity has been found in 4 cluster fields, increasing to 11 the number of known…

Infrared interferometry has fuelled a paradigm shift in our understanding of the dusty structure in the central parsecs of Active Galactic Nuclei (AGN). The dust is now thought to comprise of a hot ($\sim1000\,$K) equatorial disk, some of…

A Chandra observation of the isolated hard X-ray source XMMU J061804.3+222732, located in the region of apparent interaction of the supernova remnant IC 443 with a molecular cloud, resolved the complex structure of the source in a few…

The NASA/ISO Key Project on active galactic nuclei (AGN) seeks to better understand the broad-band spectral energy distributions (SEDs) of these sources from radio to X-rays, with particular emphasis on infrared properties. The ISO sample…

We present followup optical g', r', and i', imaging and spectroscopy of serendipitous X-ray sources detected in 6 archival Chandra, images included in the Chandra, Multiwavelength Project (ChaMP). Of the 486 X-ray sources detected between…

The Chandra HETGS spectra of the Seyfert 1 galaxy MCG--6-30-15 show numerous narrow, unresolved (FWHM < 200 km/s) absorption lines from a wide range of ionization states of N, O, Mg, Ne, Si, S, Ar, and Fe. The initial analysis of these…

We present near-IR imaging of a sample of the faint, hard X-ray sources discovered in the 2001 Chandra ACIS-I survey towards the Galactic Centre (GC) (Wang et al. 2002). These ~800 discrete sources represent an important and previously…

We present the results of a deep (280 ks) Chandra observation of the Ophiuchus cluster, the second-brightest galaxy cluster in the X-ray sky. The cluster hosts a truncated cool core, with a temperature increasing from kT~1 keV in the core…

Optical identification of hard X-ray selected BeppoSAX and Chandra sources indicates that a large fraction of the sources are ``intermediate'' AGN, i.e. type 1.8-1.9 AGN, broad-line quasars and even X-ray loud but optically dull (apparently…

We present the X-ray spectra of 86 optically-identified sources in the 13H XMM-Newton/Chandra deep field which have >70 X-ray counts. The sample consists of 50 broad line AGN, 25 narrow emission line galaxies, 6 absorption line galaxies,…

(abridged) We present a comprehensive comparison of the X-ray properties of a sample of eight dwarf starburst galaxies observed with Chandra (I Zw 18, VII Zw 403, NGC 1569, NGC 3077, NGC 4214, NGC 4449, NGC 5253, He 2-10). In Paper I we…

(abridged) We present a catalog of 2357 point sources detected during 590 ks of Chandra observations of the 17-by-17 arcminute field around Sgr A*. This field encompasses a physical area of 40 by 40 pc at a distance of 8 kpc. The…