Related papers: Extra-planar X-ray emission from disc-wide outflow…
Young stars are associated with prominent outflows of molecular gas. The ejection of gas via these outflows is believed to remove angular momentum from the protostellar system, thus permitting young stars to grow by accretion of material…
In a series of two papers we present results of a new H-alpha imaging survey, aiming at the detection of extraplanar diffuse ionized gas in halos of late-type spiral galaxies. We have investigated a sample of 74 nearby edge-on spirals,…
Numerical models of disc galaxy formation predict the existence of extended, hot ( T~10^6 K) gas haloes around present day spirals. The X-ray luminosity of these haloes is predicted to increase strongly with galaxy mass. However, searches…
I review recent results from our deep ROSAT and Chandra observations of two galaxies, M101 and NGC 4631, in fields of exceptionally low Galactic extinction. Large amounts of X-ray-emitting gas are detected in these galaxies. Such gas is…
We present here the first study of the X-ray properties of an evolutionary sample of merging galaxies. Both ROSAT PSPC and HRI data are presented for a sample of eight interacting galaxy systems, each believed to involve a similar encounter…
We present a detailed analysis of a disc galaxy forming in a high-resolution fully cosmological simulation to investigate the nature of the outer regions of discs and their relevance for the disc formation process. Specifically, we focus on…
The thermodynamics of the diffuse, X-ray emitting gas in clusters of galaxies is determined by gravitational processes associated with shock heating, adiabatic compression, and non-gravitational processes such as heating by SNe, stellar…
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…
We calculate the X-ray emission from the shocked fast wind blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric self similar solutions, we calculate the flow structure and X-ray…
The existence of partially ionized, diffuse gas and dust clouds at kiloparsec scale distances above the central planes of edge-on, galaxy discs was an unexpected discovery about 20 yrs ago. Subsequent observations showed that this EDIG…
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…
This paper presents the dynamical simulations run in the potential derived from the light distribution of 5 late-type barred spiral galaxies. The aim is to determine whether the mass distribution together with the hydrodynamical simulations…
The origin of the cold gas in central galaxies in groups is still a matter of debate. We present Multi-Unit Spectroscopic Explorer (MUSE) observations of 18 optically selected local Brightest Group Galaxies (BGGs) to study the kinematics…
Most spiral galaxies are found in galaxy groups with low velocity dispersions; most E/S0 galaxies are found in galaxy groups with relatively high velocity dispersions. The mass of the hot gas we can observe in the E/S0 groups via their…
X-ray appearance of normal galaxies is mainly determined by X-ray binaries powered by accretion onto a neutron star or a stellar mass black hole. Their populations scale with the star-formation rate and stellar mass of the host galaxy and…
The intensity of the soft X-Ray background is correlated with the distribution of galaxies. To demonstrate this, magnitude limited galaxy samples extracted from bright galaxy catalogues and the Lick counts are utilized. Significant…
The presence of radiatively driven outflows is well established in ultraluminous X-ray sources (ULXs). These outflows are optically thick and can reprocess a significant fraction of the accretion luminosity. Assuming isotropic emission,…
High redshift disc galaxies are more gas rich, clumpier, and more turbulent than local Universe galaxies. This early era of galaxy formation imprints the distribution and kinematics of the stars that we observe today, but it is not yet well…
Using the outer gap model, we investigate the emission region for the multi-wavelength light curve from energetic pulsars. We assume that gamma-ray and non-thermal X-ray photons are emitted from a particle acceleration region in the outer…
The Local Bubble (LB) is a hot, low-density cavity in the solar neighborhood, inside which the Solar System is currently located. The X-ray emission from such bubbles is strongly governed by the gas density, temperature, and the effects of…