Related papers: Star formation in a diffuse high-altitude cloud?
Aims: We derive the 3-D HI volume density distribution for the Galactic disk out to R = 60 kpc. Methods: Our analysis is based on parameters for the warp and rotation curve derived previously. The data are taken from the…
Infrared shells and bubbles are ubiquitous in the Galaxy and can generally be associated with HII regions formed around young, massive stars. In this paper, we use high-resolution 3D SPH simulations to explore the effect of a single O7 star…
Hot gaseous haloes surrounding galaxies and extending well beyond the distribution of stars are a ubiquitous prediction of galaxy formation scenarios. The haloes are believed to consist of gravitationally trapped gas with a temperature of…
The interstellar medium of galaxies, with temperatures reaching several million degrees, provides a pivotal perspective for understanding the physical and chemical properties of star formation, galactic evolution, and their associated…
The 500 central pc of the Galaxy (hereafter GC) exhibit a widespread gas component with a kinetic temperature of 100-200 K. The bulk of this gas is not associated to the well-known thermal radio continuum or far infrared sources like Sgr A…
The mass assembly history of the Milky Way can inform both theory of galaxy formation and the underlying cosmological model. Thus, observational constraints on the properties of both its baryonic and dark matter contents are sought. Here we…
We investigate the diffuse light (DL) content of dark matter haloes in the mass range $11.5\leq \log M_{halo}\leq13$, a range that includes also the dark matter halo of the Milky-Way, taking advantage of a state-of-the-art semi-analytic…
High-velocity clouds (HVCs), which are gas clouds moving at high velocity relative to the galactic disk, may play a critical role in galaxy evolution, potentially supplying gas to the disk and triggering star formation. In this study, we…
We study the formation of stellar haloes in three Milky Way-mass galaxies using cosmological smoothed particle hydrodynamics simulations, focusing on the subset of halo stars that form in situ, as opposed to those accreted from satellites.…
The extended hot X-ray emitting gaseous halo of the Milky Way has an optical depth $\sim1$ for the dominant emission lines of \ion{O}{7} and \ion{O}{8}, which are used to infer the halo properties. To improve on halo gas properties, we…
Observations of turbulent velocity dispersions in the HI component of galactic disks show a characteristic floor in galaxies with low star formation rates and within individual galaxies the dispersion profiles decline with radius. We carry…
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…
Using galaxies from the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) along with haloes from the dark matter only constrained ELUCID (Exploring the Local Universe with the reConstructed Initial Density field) simulation, we examine the…
Spiral galaxies are surrounded by a widely distributed hot coronal gas and seem to be fed by infalling clouds of neutral hydrogen gas with low metallicity and high velocities. We numerically study plasma waves produced by the collisions of…
Many high velocity HI clouds (HVCs) are now believed to be scattered throughout the Galactic halo on scales of tens of kiloparsecs. Some of these clouds appear to contain substantial HI masses (>10^6 Msun). It has been suggested that these…
Intermediate- and high-velocity clouds (IVCs, HVCs) are a potential source of fuel for star formation in the Milky Way (MW), but their origins and fates depend sensitively on their distances. We search for IVC and HVC in HST high-resolution…
We have recently identified several high velocity (V < -100 km/s) clouds in the directions of Mrk 509 and PKS 2155-304 that have unusual ionization properties. The clouds exhibit strong C IV absorption with little or no detectable low ion…
The conversion of gas into stars is a fundamental process in astrophysics and cosmology. Stars are known to form from the gravitational collapse of dense clumps in interstellar molecular clouds, and it has been proposed that the resulting…
We present new data obtained with the Submillimeter Array for a sample of fourteen nearby luminous and ultraluminous infrared galaxies. The galaxies were selected to have luminosity distances D < 200 Mpc and far-infrared luminosities…
The physical relationship between low-excitation gas filaments at ~10^4 K, seen in optical line emission, and diffuse X-ray emitting coronal gas at ~10^7 K in the centers of many galaxy clusters is not understood. It is unclear whether the…