Related papers: X-ray Emission from Early-Type Galaxies in Groups …

This paper examines the ultraviolet and X-ray photons generated by hot gas in the Galactic thick disk or halo in the Draco region of the northern hemisphere. Our analysis uses the intensities from four ions, C IV, O VI, O VII, and O VIII,…

In this paper we test the idea that the low-metallicity hot gas in the centre of NGC 1291 is heated via a dynamical process. In this scenario, the gas from the outer gas-rich ring loses energy through bar-driven shocks and falls to the…

We investigate the X-ray and mass distribution in the merging galaxy cluster 1E 0657-56. We study head-on collisions of two virialized clusters with an NFW density profile in the $\Lambda$CDM universe using an N-body + hydrodynamical code.…

We present ROSAT (HRI and PSPC) and ASCA observations of the two luminous (L_x ~10^{41-42} erg s^{-1}) star-forming galaxies NGC3310 and NGC3690. The HRI shows clearly that the sources are extended with the X-ray emission in NGC3690 coming…

The fate of cooling gas in the centers of galaxy clusters and groups is still not well understood, as is also the case for the complex processes of triggering star formation in central dominant galaxies (CDGs), re-heating of cooled gas by…

We revisit the massive isolated elliptical galaxy / fossil group NGC 6482 for which previous X-ray studies of a modest Chandra observation obtained a very uncertain, but also possibly very high, halo concentration. We present new…

We present a multi-wavlength infrared study of the nearby, edge-on, spiral galaxy NGC 891. We have examined 20 independent, spatially resolved IR images of this galaxy, 14 of which are newly reduced and/or previously unpublished images.…

We study the extended nuclear emission of the starburst galaxy NGC 1365. A weak obscured AGN and a strong starburst both contribute to the observed X-ray, optical, infrared, and radio emission in the inner 2kpc. The X-ray emission is…

Diffuse radio sources, known as mini-halos and halos, are detected at the centres of galaxy clusters. These centralized diffuse sources are typically observed individually, with both appearing together only in rare cases. The origin of the…

We have investigated the global properties of the globular cluster (GC) systems of three early-type galaxies: the Virgo elliptical NGC4406, the field elliptical NGC3379, and the field S0 galaxy NGC4594. These galaxies were observed as part…

Quillen et al.(2007) presented an imaging survey with the {\it Spitzer Space Telescope} of 62 brightest cluster galaxies with optical line emission located in the cores of X-ray luminous clusters. They found that at least half of these…

We present far-UV spectroscopy of the giant elliptical galaxy NGC 1399, obtained with the Far Ultraviolet Spectroscopic Explorer. Of all quiescent ellipticals, NGC 1399 has the strongest known ``UV upturn'' -- a sharp spectral rise…

We present CHANDRA X-ray data of the nearby Magellanic Irregular dwarf starburst galaxy NGC4449. Contributions to the X-ray emission come from discrete point sources and extended diffuse emission. The extended emission has a complex…

X-ray properties of hot interstellar gas in a starburst galaxy NGC 253 were investigated to gain a further understanding of starburst-driven outflow activity by XMM-Newton and Suzaku. Spectroscopic analysis for three regions of the galaxy…

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…

This study aims to probe the thermodynamic properties of the hot intragroup medium (IGM) plasma in the core regions of the NGC 4636 galaxy group by detailed measurements of several emission lines and their relative intensities. We analyzed…

We study the complete dynamical evolution of hot interstellar gas in massive elliptical galaxies born into a simple flat universe beginning with an overdense perturbation. Within the turn-around radius dark matter flows in a self-similar…

We present new results of a 12CO(J=1-0) imaging survey using the Atacama Compact Array (ACA) for 31 HI detected galaxies in the IC 1459 and NGC 4636 groups. This is the first CO imaging survey for loose galaxy groups. We obtained…

X-ray astronomers often divide galaxy clusters into two classes: "cool core" (CC) and "non-cool core" (NCC) objects. The origin of this dichotomy has been the subject of debate in recent years, between "evolutionary" models (where clusters…

Galaxy groups represent a significant fraction of the halo population, playing a crucial role in galaxy formation and evolution. However, their detection in X-rays remains challenging, raising questions about the physical mechanisms driving…