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Related papers: An Accurate Distance to High-Velocity Cloud Comple…

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We present deep HI 21-cm and optical observations of the face-on spiral galaxy M 83 obtained as part of a project to search for high-velocity clouds (HVCs) in nearby galaxies. Anomalous-velocity neutral gas is detected toward M 83, with…

Astrophysics · Physics 2011-02-11 Eric D. Miller , Joel N. Bregman , Bart P. Wakker

We have observed the NGC 2403 group of galaxies using the Robert C. Byrd Green Bank Telescope (GBT) in a search for faint, extended neutral hydrogen clouds similar to the clouds found around the M81/M82 group, which is located approximately…

Astrophysics of Galaxies · Physics 2015-05-13 Katie M. Chynoweth , Glen I. Langston , Kelly Holley-Bockelmann , Felix J. Lockman

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…

Astrophysics · Physics 2009-11-07 Daniel E. Welty , L. M. Hobbs , Donald C. Morton

We present a detailed analysis of the distance determination for one intermediate Velocity Cloud (IVC G139.6+47.6) from the ongoing DDO IVC Distance Project. Stars along the line of sight to G139.6+47.6 are examined for the presence of…

We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with HI column density was…

Astrophysics of Galaxies · Physics 2012-03-06 Rik J. Williams , Smita Mathur , Shawn Poindexter , Martin Elvis , Fabrizio Nicastro

A population of discrete HI clouds in the halo of the inner Galaxy has been discovered in 21cm observations made with the Green Bank Telescope. The halo clouds are seen up to 1.5 kpc from the Galactic plane at many longitudes. Their…

Astrophysics · Physics 2009-11-07 Felix J. Lockman

We present CaII K and TiII optical spectra of early-type stars taken mainly from the UVES Paranal Observatory Project, plus HI 21-cm spectra from the Vila-Elisa and Leiden-Dwingeloo surveys, which are employed to obtain distances to…

(ABRIDGED) We present a Far-Ultraviolet Spectroscopic Explorer survey of highly ionized high-velocity clouds (HVCs) in 66 extragalactic sight lines. We find a total of 63 high-velocity O VI absorbers, 16 with 21 cm-emitting H I counterparts…

Astrophysics · Physics 2009-11-11 Andrew J. Fox , Blair D. Savage , Bart P. Wakker

Analysis of interstellar absorption lines observed in high-resolution {\em HST} spectra of nearby stars provides temperatures, turbulent velocities, and kinetic properties of warm interstellar clouds. Previous studies identified 15 warm…

Astrophysics of Galaxies · Physics 2022-08-31 Jeffrey L. Linsky , Seth Redfield , Diana Ryder , Adina Chasan-Taber

We have observed 11 compact high-velocity clouds in the 21-cm line of neutral hydrogen with the 100-m telescope in Effelsberg. Our observations show that most of the clouds have a rather complex morphology. Head-tail structures and…

Astrophysics · Physics 2007-05-23 T. Westmeier , C. Bruens , J. Kerp

We present high resolution (R ~ 4 km/s) absorption measurements of the interstellar NaI and CaII lines measured towards 14 early-type stars of distance 123 pc - 1650 pc, located in the direction of the Ara OB1 stellar cluster. The line…

Astrophysics · Physics 2009-06-23 Christopher D. Henderson , Barry Y. Welsh , John B. Hearnshaw

We present hydrodynamic simulations of high-velocity clouds (HVCs) traveling through the hot, tenuous medium in the Galactic halo. A suite of models was created using the FLASH hydrodynamics code, sampling various cloud sizes, densities,…

Astrophysics of Galaxies · Physics 2015-05-28 Kyujin Kwak , David B. Henley , Robin L. Shelton

We show 21-cm line profiles in the direction of stars and extragalactic objects, lying projected on high- and intermediate-velocity clouds (HVCs and IVCs). About half of these are from new data obtained with the Effelsberg 100-m telescope,…

Astrophysics · Physics 2009-11-06 B. P. Wakker , P. M. W. Kalberla , H. van Woerden , K. S. de Boer , M. E. Putman

Previous HST and FUSE observations have revealed highly ionized high-velocity clouds (HVCs) or more generally low HI column HVCs along extragalactic sightlines over 70-90% of the sky. The distances of these HVCs have remained largely…

Astrophysics of Galaxies · Physics 2015-05-14 N. Lehner , J. C. Howk

We present HI observations of the compact high-velocity cloud HVC289+33+251 that was discovered by Putman et al. (2002). Observations with the 100-m Effelsberg telescope demonstrate that this cloud is still unresolved by the 9' beam of the…

Astrophysics · Physics 2011-08-23 C. Bruens , T. Westmeier

We present ultra-high resolution (0.32 km/s) spectra obtained with the 3.9m Anglo-Australian Telescope (AAT) and Ultra-High-Resolution Facility (UHRF), of interstellar NaI D1, D2, Ca II K, K I and CH absorption toward two high galactic…

Astrophysics · Physics 2009-10-30 M. S. Sahu , J. C. Blades , L. He , D. Hartmann , M. J. Barlow , I. A. Crawford

We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the sightline toward the Seyfert 1 galaxy Markarian 876, which passes through high velocity cloud (HVC) complex C. This sight line demonstrates the ability of FUSE to…

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…

Using Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope observations of the QSO PG1259+593, we detect D I Lyman-series absorption in high velocity cloud Complex C, a low-metallicity gas cloud falling onto the Milky Way. This…

The nature of the Local Interstellar Cloud (LIC) is highly constrained by the combination of in situ heliospheric and line-of-sight data towards nearby stars. We present a new interpretation of the LIC components of the absorption line data…

Astrophysics · Physics 2011-02-11 Jonathan D. Slavin , Priscilla C. Frisch