Related papers: High-Velocity Clouds and the Local Intergalactic M…

We have studied the UV extinction properties along 30 Galactic sightlines using data from the International Ultraviolet Explorer (IUE) archive that have never been previously examined. These distant (d > 1 kpc) sightlines were selected to…

We report the discovery of molecular hydrogen absorption in a Galactic high-velocity cloud (HVC) in the direction of the Large Magellanic Cloud. For the same HVC we derive an iron abundance which is half of the solar value. Thus, all…

Recent observations in the 21cm line with the Green Bank Telescope have changed our view of the neutral interstellar medium (ISM) in several ways. The new data show that in the inner parts of the Milky Way the disk-halo interface is…

Using data from the Galactic All-Sky Survey, we have compared the properties and distribution of HI clouds in the disk-halo transition at the tangent points in mirror-symmetric regions of the first quadrant (QI) and fourth quadrant (QIV) of…

Following the first pioneering efforts in the 1990s that have focused on the detection of the molecular interstellar medium in high redshift galaxies, recent years have brought great advances in our understanding of the actual physical…

Galaxies evolve under the influence of gas flows between their interstellar medium and their surrounding gaseous halos known as the circumgalactic medium (CGM). The CGM is a major reservoir of galactic baryons and metals, and plays a key…

We investigate the relative distribution of the gaseous contents of the Universe (as traced by a sample of Lyman alpha (lya) absorbers), and the luminous baryonic matter (as traced by a redshift survey of galaxies in the same volume…

Using the Hubble Space Telescope, we have resolved individual red-giant branch stars in the halos of eight nearby spiral galaxies. The fields lie at projected distances between 2 and 13 kpc along the galaxies' minor axes. The data set…

Galaxies are part of a vast cosmic ecosystem, embedded in an extensive gaseous reservoir that regulates their growth by providing the necessary fuel for star formation while preserving a fossil record of past interactions, outflows, and…

We use deep MUSE data from the MUDF survey to investigate the cool gas around galaxies at redshifts 0.5 < z < 2. We constructed two samples: one sample for a down-the-barrel analysis, probing outflows via MgII absorption against galaxy…

We have obtained high resolution (FWHM = 4.4 km/s) Keck spectra of images A and C of the gravitationally lensed QSO Q1422+231. The images are separated by 1.3" on the sky. In an absorption system at z = 3.538 gas column density variations…

A recent discovery of two stellar clusters associated with the diffuse high-latitude cloud HRK 81.4-77.8 has important implications for star formation in the Galactic halo. We derive a plausible distance estimate to HRK 81.4-77.8 primarily…

We study the vertical density distribution of stars and gas (HI and H_2) in a galactic disk which is embedded in a dark matter halo. The new feature of this work is the inclusion of gas, and the gravitational coupling between stars and gas,…

Continued star formation over the lifetime of a galaxy suggests that low metalicity gas is steadily flowing in from the circumgalactic medium. Also, cosmological simulations of large-scale structure formation imply that gas is accreted onto…

We use 666 blue horizontal branch (BHB) stars from the 2Qz redshift survey to map the Galactic halo in four dimensions (position, distance and velocity). We find that the halo extends to at least 100 kpc in Galactocentric distance, and…

We study the kinematics of the gaseous cosmic web at high redshift with Lyman alpha forest absorption in multiple QSO sightlines. Using a simple analytic model and a cosmological hydrodynamic simulation we constrain the underlying…

Dwarf galaxies provide a special environment due to their low mass, small size and generally low metal content. These attributes make them perfect laboratories for the interaction of massive stars with the interstellar medium on small and…

We combine observations of spiral galaxies in the [CII] line at 158 micron, made with the Long Wavelength Spectrometer aboard ISO, with previous data from the Kuiper Airborne Observatory to study the origin of this line, which is the main…

Deep photometric surveys of the Milky Way have revealed diffuse structures encircling our Galaxy far beyond the "classical" limits of the stellar disk. This paper reviews results from our own and other observational programs, which together…

This paper systematically investigates comoving Mpc scale intergalactic medium (IGM) environment around galaxies traced by the Ly$\alpha$ forest. Using our cosmological hydrodynamic simulations, we investigate the IGM-galaxy connection at…