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Related papers: The Small-scale Structure in Interstellar HI: A Re…

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This paper considers some effects of foreground Galactic gas on radiation received from extragalactic objects, with an emphasis on the use of the 21cm line to determine the total N(HI). In general, the opacity of the 21cm line makes it…

Astrophysics · Physics 2016-01-27 Felix J. Lockman

Studies of the HI in galaxies have clearly shown that subtle details of the HI distribution and kinematics often harbour key information for understanding the structure and evolution of galaxies. Evidence for the accretion of material has…

Astrophysics · Physics 2007-05-23 Thijs van der Hulst , Renzo Sancisi

We have compiled the most complete compact and ultracompact HII region catalogue to date via multi-wavelength inspection of survey data. We utilise data from the recently available SASSy 850$\mu$m survey to identify massive star forming…

Astrophysics of Galaxies · Physics 2019-07-24 J. O. Djordjevic , M. A. Thompson , J. S. Urquhart , J. Forbrich

A composite map of HI in the LMC using the ATCA interferometer and the Parkes multibeam telescope was analyzed in several ways in an attempt to characterize the structure of the neutral gas and to find an origin for it. Fourier transform…

Astrophysics · Physics 2014-10-13 Bruce G. Elmegreen , Sungeun Kim , Lister Staveley-Smith

Diffuse interstellar bands (DIBs) hold a lot of information about the state and the structure of the ISM. Structure can most directly be observed by extensive spectroscopic surveys, including surveys of stars where DIBs are especially…

Astrophysics of Galaxies · Physics 2017-05-10 Janez Kos

We built a multi-wavelength dataset for galaxies from the Local Volume HI Survey (LVHIS), which comprises 82 galaxies. We also select a sub-sample of ten large galaxies for investigating properties in the galactic outskirts. The LVHIS…

We identify 814 discrete HI clouds in 40 dwarf irregular galaxies from the LITTLE THINGS survey using an automated cloud-finding algorithm. The cloud masses range from ~10^3 to 10^7 Msolar, have a surface density averaged over all of the…

Astrophysics of Galaxies · Physics 2019-06-05 Deidre A. Hunter , Bruce G. Elmegreen , Clara L. Berger

We present high S/N measurements of the H I Ly alpha absorption line toward 16 Galactic targets which are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove…

Astrophysics of Galaxies · Physics 2023-04-05 S. D. Friedman , P. Chayer , E. B. Jenkins , T. M. Tripp , G. M. Williger , G. Hebrard , P. Sonnentrucker

We have made a statistically complete, unbiased survey of C IV systems toward a region of high QSO density near the South Galactic Pole using 25 lines of sight spanning $1.5<z<2.8$. Such a survey makes an excellent probe of large-scale…

Astrophysics · Physics 2015-06-24 G. M. Williger , C. Hazard , J. A. Baldwin , R. G. McMahon

We present methods and results from "21-cm Spectral Line Observations of Neutral Gas with the EVLA" (21-SPONGE), a large survey for Galactic neutral hydrogen (HI) absorption with the Karl G. Jansky Very Large Array (VLA). With the upgraded…

We present HST/GHRS echelle observations of multiple interstellar lines of CI, MgI, CrII, and ZnII towards both stars in the mu Cru binary system. Despite large differences in the profiles of the neutral species, no significant variations…

Astrophysics · Physics 2009-10-30 J. T. Lauroesch , David M. Meyer , John K. Watson , J. C. Blades

The HI Parkes All-Sky Survey (HIPASS) gives an unprecedented view of the local large-scale structures in the southern sky. I will review the results from the HIPASS Bright Galaxy Catalog (BGC, Koribalski et al. 2004) and the first version…

Astrophysics · Physics 2007-05-23 B. S. Koribalski

We present a study of the small-scale structure of the interstellar medium in the Milky Way. We used HST STIS data to measure N(HI) in a pencil-beam toward 59 AGNs and compared the results with the values seen at 9 arcmin - 36 arcmin…

Astrophysics of Galaxies · Physics 2015-05-20 Bart P. Wakker , Felix J. Lockman , Jonathan M. Brown

Tracing the transition between the diffuse atomic interstellar medium (ISM) and cold, dense gas is crucial for deciphering the star formation cycle in galaxies. Here we present MACH, a new survey of cold neutral hydrogen (HI) absorption at…

We resolve the kinematic distance ambiguity for 266 inner Galaxy HII regions out of a sample of 291 using existing HI and 13CO sky surveys. Our sample contains all HII regions with measured radio recombination line (RRL) emission over the…

Astrophysics · Physics 2008-12-18 L. D. Anderson , T. M. Bania

Hydrogen column densities inferred from X-ray absorption are typically 5 - 30 times larger than the neutral atomic hydrogen column densities derived from 21cm HI absorption toward radio-loud active galactic nuclei. Some part of the…

Astrophysics of Galaxies · Physics 2021-02-24 Harvey Liszt

The Hubble constant is one of the most important parameters in cosmology. Discrepancies in values of the Hubble constant estimated from various measurements, the so-called Hubble tension, are a serious problem. In this paper, we study the…

General Relativity and Quantum Cosmology · Physics 2025-02-03 Taishi Miura , Takahiro Tanaka

The presence, distribution and kinematics of atomic neutral hydrogen in the central regions of galaxies can be traced by the HI 21~cm line observed in absorption. Depending only on the strength of the radio continuum, the associated…

Astrophysics of Galaxies · Physics 2024-12-11 Raffaella Morganti

This is the second paper of two reporting results from a study of the HI content and stellar properties of nearby galaxies detected by the Arecibo Legacy Fast ALFA blind 21-cm line survey and the Sloan Digital Sky Survey in a 2160 deg^2…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 M. C. Toribio , J. M. Solanes , R. Giovanelli , M. P. Haynes , A. Martin

A search for HI absorption has been made in 23 radio galaxies using the ATCA, the VLA and the WSRT. In five galaxies HI absorption was detected. We investigate how the detection rate is distributed among galaxies with different radio and…

Astrophysics · Physics 2009-10-31 R. Morganti , T. A. Oosterloo , C. N. Tadhunter , G. van Moorsel , N. Killeen , K. A. Wills