English
Related papers

Related papers: Small-Scale structure in the Galactic ISM: Implica…

200 papers

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 present 21 cm HI line observations of 5x1 square degrees centered on the local Abell cluster 1367 obtained as part of the Arecibo Galaxy Environment Survey. One hundred sources are detected (79 new HI measurements and 50 new redshifts),…

We present results of a blind search for Galactic HI 21-cm absorption lines toward 19130 radio sources, using 390 pointings of MALS, each pointing centered on a source brighter than 200 mJy. We detected 3640 HI absorption features. This…

Obtaining a complete census of gas in the local interstellar medium (<100 pc) is challenging given the limited available tracers of the warm, partially-ionized medium. Medium-to-high resolution UV absorption spectroscopy toward individual…

HI 21~cm absorption spectroscopy provides an excellent probe of the neutral gas content of absorbing galaxies, yielding information on their kinematics, mass, physical size and ISM conditions. The high sensitivity, unrivaled frequency…

Astrophysics · Physics 2009-11-10 N. Kanekar , F. H. Briggs

We discuss ROSAT HRI X-ray observations of 33 very nearby galaxies, sensitive to X-ray sources down to a luminosity of approximately 10^38 erg/s. The galaxies are selected from a complete, volume limited sample of 46 galaxies with d<7 Mpc…

Astrophysics · Physics 2009-10-31 P. Lira , A. Lawrence , R. A. Johnson

As a complement to the HyGAL Stratospheric Observatory for Infrared Astronomy Legacy Program, we report the results of a ground-based absorption line survey of simple molecules in diffuse and translucent Galactic clouds. Using the Institut…

We present an HI absorption survey of the central 250 pc of the Galaxy. Very Large Array (VLA) observations were made at 21 cm in the DnC and CnB configurations and have a resolution of ~15"(0.6 pc at the Galactic Center (GC) distance) and…

Astrophysics of Galaxies · Physics 2015-05-20 Cornelia C. Lang , W. Miller Goss , Claudia Cyganowski , Kelsey I. Clubb

A high latitude HI 21 cm-line absorption survey toward extragalactic sources was recently completed using the Giant Meterwave Radio Telescope (GMRT). A total of 104 sources with mod(b) > 15 deg. and with a 21 cm flux density greater than 1…

Astrophysics · Physics 2007-05-23 K. S. Dwarakanath

The observation of 21 X-ray dust-scattering rings around the extraordinarily bright gamma-ray burst (GRB) 221009A provides a unique opportunity to study the interstellar medium (ISM) through which the X-ray radiation traveled in our Galaxy…

High Energy Astrophysical Phenomena · Physics 2025-04-02 B. Vaia , Ž. Bošnjak , A. Bracco , S. Campana , P. Esposito , V. Jelić , A. Sacchi , A. Tiengo

We have used the Giant Meterwave Radio Telescope (GMRT) to measure the Galactic HI 21-cm line absorption towards 102 extragalactic radio continuum sources, located at high (|b| >15deg.) Galactic latitudes. The Declination coverage of the…

Astrophysics · Physics 2009-11-10 Rekhesh Mohan , K. S. Dwarakanath , G. Srinivasan

Several claims have been made that we are located in a locally underdense region of the Universe based on observations of supernovae and galaxy density distributions. Two recent studies of K-band galaxy surveys have provided new support for…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-21 Hans Boehringer , Gayoung Chon , Martyn Bristow , Chris A. Collins

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

The Southern Galactic Plane Survey (SGPS) is a project to image the HI line emission and 1.4 GHz continuum in the fourth quadrant of the Milky Way at high resolution using the Australia Telescope Compact Array (ATCA) and the Parkes Radio…

We describe the use of partially overlapping galaxies to provide direct measurements of the effective absorption in galaxy disks, independent of assumptions about internal disk structure. The non-overlapping parts of the galaxies and…

Astrophysics · Physics 2007-05-23 Raymond E. White , William C. Keel , Christopher J. Conselice

A survey of 329 nearby galaxies (redshift z < 0.045) has been conducted to study the distribution of mass and light within spiral galaxies over a range of environments. The 18 observed clusters and groups span a range of richness, density,…

Astrophysics · Physics 2009-11-10 Nicole P. Vogt , Martha P. Haynes , Terry Herter , Riccardo Giovanelli

We present a study, done with the Australian LBA, of HI absorption for two compact radio galaxies (PKS 1549-79 and PKS 1814-63). In both the radio galaxies, the HI appears to give us information about the environment in which the radio…

Astrophysics · Physics 2007-05-23 R. Morganti , T. A. Oosterloo , C. N. Tadhunter , K. A. Wills , A. Tzioumis , J. Reynolds

We propose a method to determine the power spectrum of \HI column density fluctuations using radio-interferometric observations of 21-cm emission from the ISM of galaxies. We have used this to estimate the power spectra of six nearly face…

Astrophysics of Galaxies · Physics 2015-06-16 Prasun Dutta , Somnath Bharadwaj

The intracluster medium (ICM) in the far outskirts (r $>$ 2-3 R$_{200}$) of galaxy clusters interfaces with the intergalactic medium (IGM) and is theorized to comprise diffuse, multiphase gas. This medium may hold vital clues to clusters'…

We present a new X-ray analysis mainly based on ROSAT HRI data. The HRI spatial resolution combined with an improved wavelet analysis method and with complementary radio and optical data provides new results compared to a previous paper…

Astrophysics · Physics 2007-05-23 G. B. Lima Neto , V. Pislar , F. Durret , D. Gerbal , E. Slezak