Related papers: X-ray Emission from Early-Type Galaxies in Groups …
We present the first high-resolution X-ray spectrum of the Seyfert 1.5 galaxy NGC 4151. Observations with the Chandra High Energy Transmission Grating Spectrometer reveal a spectrum dominated by narrow emission lines from a spatially…
Aims: We present a study of the diffuse X-ray emission in the halo and the disc of the starburst galaxy NGC 253. Methods: After removing point-like sources, we analysed XMM-Newton images, hardness ratio maps and spectra from several regions…
The variation of temperature and density in the hot, X-ray emitting gas around massive, group dominant elliptical galaxies can be understood as a combination of gas ejected from evolving galactic stars and gas that accumulates in the outer…
(Abridged) We observed the X-ray bright E3 galaxy NGC 1600 and nearby group members with the Chandra X-ray Observatory ACIS S3. Unresolved emission dominates the observation; however, we resolved some emission into 71 sources, most of which…
We have undertaken a multiwavelength project to study the relatively unknown properties of groups and poor clusters of galaxies at intermediate redshifts. In this paper, we describe the XMM-Newton observations of six X-ray selected groups…
From the point of view of X-ray astronomers, galaxy clusters are usually divided into two classes: "cool core"(CC) and "non-cool core" (NCC) objects. The origin of this dichotomy has been subject of debate in recent years, between…
We present a two-dimensional analysis of the bright nearby galaxy group NGC 5044 using the currently available Chandra and XMM data. In the inner 10 kpc a pair of cavities are evident together with a set of bright X-ray filaments. If the…
The elliptical galaxy NGC 1550 at a redshift of $z=0.01239$, identified with an extended X-ray source RX J0419+0225, was observed with {\it XMM-Newton} for 31 ks. From the X-ray data and archival near infra-red data of Two Micron All Sky…
We use a new fiber spectroscopic survey of 12 nearby, poor groups of galaxies to examine the dynamics and evolution of galaxies in these common, but poorly studied, environments. Some of our conclusions are: (1) The nine groups in our…
The knowledge of the X-ray properties of the hot gas halos of early-type galaxies has significantly advanced in the past years, for large and homogeneously investigated samples. We compare these results with the X-ray properties of an…
This study examines the average X-ray properties of massive halos at z< 0.2, covering the largest halo mass range to date, from Milky Way-like halos to massive clusters. The analysis is based on stacking in the eFEDS area of the GAMA galaxy…
We revisit the question of the ionization of the diffuse medium in late type galaxies, by studying NGC 891, the prototype of edge-on spiral galaxies. The most important challenge for the models considered so far was the observed increase of…
Chandra images of galaxy clusters have revealed a wealth of structure unseen by previous generations of low resolution X-ray observatories. In the cores of clusters, bright, irregular X-ray emission is now routinely seen within central…
We present an X-ray analysis of the rich cluster ABCG 85 based on ROSAT PSPC data. By applying an improved wavelet analysis, we show that our view of this cluster is notably changed from what was previously believed (a main region and a…
Galaxy groups are the least massive systems where the bulk of baryons begin to be accounted for. Not simply the scaled-down versions of rich clusters following self-similar relations, galaxy groups are ideal systems to study baryon physics,…
A homogeneous spectroscopic analysis of unevolved and evolved stars in the metal-poor globular cluster NGC 6397 with FLAMES-UVES reveals systematic trends of stellar surface abundances that are likely caused by atomic diffusion. This…
We have analyzed the Chandra archival data of NGC 1132, a well-known fossil group, i.e. a system expected to be old and relaxed long after the giant elliptical galaxy assembly. Instead, the Chandra data reveal that the hot gas morphology is…
The nearly face-on SBc galaxy M83 (NGC 5236) was observed for 25 ksec with the ROSAT PSPC. We detected 13 point-like sources in this galaxy, 10 of which were previously unknown. We measured extended X-ray radiation from almost the whole…
We present Hubble Space Telescope far-UV spectra of 4 QSOs whose sightlines pass through the halo of NGC 1097 at impact parameters of 48 -165 kpc. NGC 1097 is a nearby spiral galaxy that has undergone at least two minor merger events, but…
(abridged) We present an analysis of Chandra X-ray observations of a sample of eight dwarf starburst galaxies (I Zw 18, VII Zw 403, NGC 1569, NGC 3077, NGC 4214, NGC 4449, NGC 5253, and He 2-10). Extended, diffuse X-ray emission is detected…