Related papers: Extracting the cold neutral medium from HI emissio…
Following Bi & Davidsen (1997), we perform one dimensional semi analytic simulations along the lines of sight to model the intergalactic medium (IGM). Since this procedure is computationally efficient in probing the parameter space -- and…
Strong gravitational lensing provides some of the deepest views of the Universe, enabling studies of high-redshift galaxies only possible with next-generation facilities without the lensing phenomenon. To date, 21 cm radio emission from…
We evaluate recent and upcoming low-redshift neutral hydrogen (HI) surveys as a cosmological probe of small scale structure with a goal of determining the survey criteria necessary to test ultra-light axion (ULA) dark matter models.…
We investigate the 21-cm signature that may arise from the intergalactic medium (IGM) prior to the epoch of full reionization (z>5). In scenarios in which the IGM is reionized by discrete sources of photoionizing radiation, the neutral gas…
We report statistically significant detection of H I 21-cm emission from intermediate-redshift ($z\approx0.2$-0.6) galaxies. By leveraging multi-sightline galaxy survey data from the Cosmic Ultraviolet Baryon Survey (CUBS) and deep radio…
Neutral Hydrogen Intensity Mapping (HI IM) surveys will be a powerful new probe of cosmology. However, strong astrophysical foregrounds contaminate the signal and their coupling with instrumental systematics further increases the data…
The emission from neutral hydrogen (HI) clouds in the post-reionization era (z < 6), too faint to be individually detected, is present as a diffuse background in all low frequency radio observations below 1420 MHz. The angular and frequency…
The [CII] fine--structure line at 158um is an excellent tracer of the warm diffuse gas in the ISM and the interfaces between molecular clouds and their surrounding atomic and ionized envelopes. Here we present the initial results from…
We measure the effect of high column density absorbing systems of neutral hydrogen (HI) on the one-dimensional (1D) Lyman-alpha forest flux power spectrum using cosmological hydrodynamical simulations from the Illustris project. High column…
Detecting neutral Hydrogen (H\,{\sc i}) via the 21~cm line emission from the intergalactic medium at $z\gtrsim 6$ has been identified as one of the most promising probes of the epoch of cosmic reionization -- a major phase transition of the…
We present a measurement of the HI column density distribution function, f(N), at the present epoch for column densities log N > 20 cm^-2. These high column densities compare to those measured in damped Ly alpha lines seen in absorption…
The Lyman Alpha damping wing is seen in absorption against the spectra of high-redshift galaxies. Modeling of this wing is a way to measure the volume neutral hydrogen fraction of the Universe, as well as to measure the strength of HI…
Dwarf irregular galaxies are unique laboratories for studying the interaction between stars and the interstellar medium in low mass environments. We present the highest spatial resolution observations to date of the neutral hydrogen content…
The large-scale structure of the Universe supplies crucial information about the physical processes at play at early times. Unresolved maps of the intensity of 21 cm emission from neutral hydrogen HI at redshifts z~1-5 are the best hope of…
The HI and CO components of the interstellar medium (ISM) are usually used to derive the dynamical mass M_dyn of nearby galaxies. Both components become too faint to be used as a tracer in observations of high-redshift galaxies. In those…
We use the Gaussian-fit results of Paper I to investigate the properties of interstellar HI in the Solar neighborhood. The Warm and Cold Neutral Media (WNM and CNM) are physically distinct components. The CNM spin temperature histogram…
Atomic hydrogen (HI) dominates the mass of the cold interstellar medium, undergoing thermal condensation to form molecular gas and fuel star formation. Kinematically colder HI components, identified via kinematic decomposition of HI 21 cm…
Large scale filaments, with lengths that can reach tens of Mpc, are the most prominent features in the cosmic web. These filaments have only been observed indirectly through the positions of galaxies in large galaxy surveys or through…
We present high-resolution (FWHM ~ 0.3-1.5 km/s) spectra of interstellar Ca I absorption toward 30 Galactic stars. Comparisons of the column densities of Ca I, Ca II, K I, and other species -- for individual components identified in the…
We present new multi-wavelength scaling relations between the neutral hydrogen content (HI) and the stellar properties of nearby galaxies selected from the HI Parkes All-Sky Survey (HIPASS). We use these new scaling relations to investigate…