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Related papers: Distance Constraints for High Velocity Clouds from…

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We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which…

Solar and Stellar Astrophysics · Physics 2015-06-05 Warren A. Reid , Quentin A. Parker

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 report the first observations of far-ultraviolet (FUV: 1000 -- 1150 \AA) diffuse radiation from the Small Magellanic Cloud (SMC) using observations from the {\em Far Ultraviolet Spectroscopic Explorer (FUSE)}. The strength of FUV diffuse…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Ananta C. Pradhan , Jayant Murthy , Amit Pathak

Using a sample of nearly half million galaxies, intersected by over 7 million lines of sight from the Sloan Digital Sky Survey Data Release 12, we trace H$\alpha$ + [N{\small II}] emission from a galactocentric projected radius, $r_p$, of 5…

Astrophysics of Galaxies · Physics 2016-12-28 Huanian Zhang , Dennis Zaritsky , Guangtun Zhu , Brice Ménard , David W. Hogg

In the spectra of 139 early-type Large Magellanic Cloud (LMC) stars observed with FUSE and with deep radio Parkes HI 21-cm observations along those stars, we search for and analyze the absorption and emission from high-velocity gas at…

Astrophysics of Galaxies · Physics 2009-08-24 N. Lehner , L. Staveley-Smith , J. C. Howk

We have detected absorption lines from the High Velocity Cloud Complex WB in the spectrum of the star HE1048+0231. This detection sets an upper distance limit to the cloud of 8.8^{+2.3}_{-1.3} kpc. Non-detection (at >4 sigma confidence) in…

Astrophysics · Physics 2009-11-11 C. Thom , M. E. Putman , B. K. Gibson , N. Christlieb , C. Flynn , T. C. Beers , R. Wilhelm , Y. S. Lee

High-velocity clouds (HVCs) are multi-phase gas structures whose velocities (|v_LSR|>100 km/s) are too high to be explained by Galactic disk rotation. While large HVCs are well characterized, compact and small HVCs (with HI angular sizes of…

High-velocity clouds (HVC), fast-moving ionized and neutral gas clouds found at high galactic latitudes, may play an important role in the evolution of the Milky Way. The extent of this role depends sensitively on their distances and total…

Astrophysics of Galaxies · Physics 2015-06-04 N. Lehner , J. C. Howk , C. Thom , A. J. Fox , J. Tumlinson , T. M. Tripp , J. D. Meiring

The Magellanic Stream (MS) is a well-resolved gaseous tail originating from the Magellanic Clouds. Studies of its physical properties and chemical composition are needed to understand its role in Galactic evolution. We investigate the…

Astrophysics of Galaxies · Physics 2015-06-23 Nimisha Kumari , Andrew J. Fox , Jason Tumlinson , Christopher Thom , Tobias Westmeier , Justin Ely

We suggest that the high--velocity clouds (HVCs) are large clouds, with typical diameters of 25 kpc and containing 5e7 solar masses of neutral gas and 3e8 solar masses of dark matter, falling onto the Local Group; altogether the HVCs…

Astrophysics · Physics 2010-11-23 Leo Blitz , David N. Spergel , Peter J. Teuben , Dap Hartmann , W. Butler Burton

The Fermi satellite discovery of the gamma-ray emitting bubbles extending 50 deg (10 kpc) from the Galactic Centre has revitalized earlier claims that our Galaxy has undergone an explosive episode in the recent past. We now explore a new…

Astrophysics of Galaxies · Physics 2015-06-17 Joss Bland-Hawthorn , Phil Maloney , Ralph Sutherland , Greg Madsen

We estimate the abundances of S and Fe in the high velocity cloud HVC 287.5+22.5+240, which has a velocity of +240 km/s with respect to the local standard of rest and is in the Galactic direction l~287, b~23. The measurements are based on…

We have recently used the Hubble Space Telescope to study a pair of high velocity clouds in the direction of Mrk 509 that have unusual ionization properties. They exhibit strong CIV absorption with little or no low ion absorption or HI 21cm…

Astrophysics · Physics 2007-05-23 Kenneth R. Sembach , Blair D. Savage , Limin Lu , Edward M. Murphy

We study an undocumented large translucent cloud, detected by means of its enhanced radiation on the SHASSA (Southern H-Alpha Sky Survey Atlas) survey. We consider whether its excess surface brightness can be explained by light scattered…

Astrophysics of Galaxies · Physics 2015-05-19 K. Lehtinen , M. Juvela , K. Mattila

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the…

Astrophysics · Physics 2009-11-07 S. L. Tufte , J. D. Wilson , G. J. Madsen , L. M. Haffner , R. J. Reynolds

We present a new technique to identify associations of HI emission in the Magellanic Stream (MS) and ultraviolet (UV) absorbers from 92 QSO sight lines near the MS. We quantify the level of associations of individual HI elements to the main…

Astrophysics of Galaxies · Physics 2024-02-15 Doyeon A. Kim , Yong Zheng , Mary E. Putman

The Far Ultraviolet Spectroscopic Explorer (FUSE) has observed over three hundred fifty sightlines to extragalactic targets. About one hundred fifty of these are of sufficient quality to measure OVI absorption in and near the Milky Way.…

We measure the properties of optical emission lines in multiple locations across the Large Magellanic Cloud (LMC) using the Australian National University 2.3-metre telescope and the WiFeS integral field spectrograph. From these…

Astrophysics of Galaxies · Physics 2024-03-05 Philip Lah , Matthew Colless , Francesco D'Eugenio , Brent Groves , Joseph D. Gelfand

We present a new measurement, 0.85-3.5 Z_solar, of the metallicity of high velocity cloud (HVC) Complex M by analyzing ultraviolet spectroscopic observations of the blazar Mrk 421 taken with the Cosmic Origins Spectrograph on the Hubble…

Astrophysics of Galaxies · Physics 2015-05-27 Yangsen Yao , J. Michael Shull , Charles W. Danforth

Various scenarios have been proposed to explain the origin of the Galactic high-velocity clouds, predicting different distances and implying widely varying properties for the Galaxy's gaseous halo. To eliminate the difficulties of studying…

Astrophysics · Physics 2007-05-23 Eric D. Miller , Joel N. Bregman