相关论文: Recent X-ray Observations of Disk Galaxies: Tracin…

It is widely believed that galaxy formation and evolution is regulated by stellar mechanical feedback in forms of fast stellar winds and supernova explosions. However, the coupling of this feedback with the interstellar medium remains…

We performed a Chandra X-ray study of three giant H II regions (GHRs), NGC 5461, NGC 5462, and NGC 5471, in the spiral galaxy M101. The X-ray spectra of the three GHRs all contain a prominent thermal component with a temperature of ~0.2…

We study the emission from the hot interstellar medium in a sample of nearby late type galaxies defined in Paper I. Our sample covers a broad range of star formation rates, from ~0.1 Msun/yr to ~17 Msun/yr and stellar masses, from ~3x10^8…

We performed five pointing observations with Suzaku to search for hot gases associated with the junctions of galaxy filaments where no significant diffuse X-ray sources were detected so far. We discovered X-ray sources successfully in all…

Two lines of evidence indicate that active galaxies, principally radio galaxies, have heated the diffuse hot gas in clusters. The first is the general need for additional heating to explain the steepness of the X-ray luminosity--temperature…

I review our recent Chandra surveys of the center region of the Milky Way and other nearby edge-on galaxies. Our Galactic center survey provides an unprecedented high-resolution, broad-band X-ray panorama of a 0.8x2 square degree swath…

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…

Recent, high sensitivity, HI observations of nearby spiral galaxies show that their thin `cold' disks are surrounded by thick layers (halos) of neutral gas with anomalous kinematics. We present results for three galaxies viewed at different…

Spiral galaxies must acquire gas to maintain their observed level of star formation beyond the next few billion years (Leroy et al. 2008). A source of this material may be the gas that resides between galaxies, but our understanding of the…

Suzaku observation of the edge-on spiral galaxy NGC 4631 confirmed its X-ray halo extending out to about 10 kpc from the galactic disk. The XIS spectra yielded the temperature and metal abundance for the disk and the halo regions. The…

A significant fraction of baryons in galaxies are in the form of diffuse gas of the circumgalactic medium (CGM). One critical component of the multi-phases of CGM, the so-called "coronal" warm-hot phase gas ($\rm 10^{5}-10^{6}$ K) traced by…

(Abridged) We have obtained spectra of 135 HII regions located in the inner and extended disks of the spiral galaxies NGC 1512 and NGC 3621, spanning the range of galactocentric distances 0.2-2 x R25 (from 2-3 kpc to 18-25 kpc). We find…

There is mounting evidence for an extra-planar gas layer around the Milky Way disk, similar to the anomalous HI gas detected in a few other galaxies. As much as 10% of the gas may be in this phase. We analyze HI clouds located in the…

We have analyzed observations with the Chandra X-ray Observatory of the diffuse emission by hot gas in 7 dwarf starburst galaxies, 6 edge-on starburst galaxies, and 9 Ultra Luminous Infrared Galaxies. These systems cover ranges of \~ 10^4…

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 explore the warm molecular and ionized gas in the centers of two megamaser disk galaxies using K-band spectroscopy. Our ultimate goal is to determine how gas is funneled onto the accretion disk, here traced by megamaser spots on sub-pc…

There is a linear relation between the mass of dense gas, traced by the HCN(1-0) luminosity, and the star formation rate (SFR), traced by the far-infrared luminosity. Recent observations of galactic disks have shown some systematic…

High resolution 2D hydrodynamical simulations describing the evolution of the hot ISM in axisymmetric two-component models of early-type galaxies well reproduced the observed trends of the X-ray luminosity ($L_\mathrm{x}$) and temperature…

We present deep Halpha images of three nearby late-type spiral galaxies (NGC628, NGC1058 and NGC6946), which reveal the presence of HII regions out to, and beyond, two optical radii (defined by the 25th B-band isophote). The outermost HII…

Galaxies are surrounded by large halos of hot gas which must be replenished as the gas cools. This led Norman & Ikeuchi (1989) to propose the chimney model of the interstellar medium, which predicts that there should be on the order of a…