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Related papers: Variable Interstellar Absorption toward the Halo S…

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We present observations of HI and OVI absorption systems proximate to a galaxy at z_gal = 0.3529. The absorption was detected serendipitously in Cosmic Origins Spectrograph observations of the low-z QSO J0943+0531 (z_qso = 0.564). The data…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 C. Thom , J. K. Werk , J. Tumlinson , J. X. Prochaska , J. D. Meiring , T. M. Tripp , K. R. Sembach

We present an analysis of interstellar absorption lines in high-resolution optical echelle spectra of SS Cyg obtained during an outburst in 2013 June and in archival Hubble Space Telescope and Far Ultraviolet Spectroscopic Explorer data.…

Astrophysics of Galaxies · Physics 2018-06-07 Adam M. Ritchey , George Wallerstein , Jean McKeever

We present FUSE and HST/STIS observations of the absorption line system near the emission redshift of the radio-quiet, X-ray bright quasar HE0226-4110 (z = 0.495, V=15.2). The spectra cover the rest-frame wavelength range 610--1150 A, and…

Astrophysics · Physics 2009-11-11 Rajib Ganguly , Kenneth R. Sembach , Todd M. Tripp , Blair D. Savage , Bart P. Wakker

Recent JWST observations of massive galaxies at z > 2 have detected blueshifted absorption in Na I D and other resonant absorption lines, indicative of strong gas outflows in the neutral phase. However, the measured mass outflow rates are…

To gain insight into four highly ionized high-velocity clouds (HVCs) discovered by Sembach et al. (1999), we have analyzed data from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) for the PKS 2155-304 and…

Astrophysics · Physics 2009-11-10 J. A. Collins , J. M. Shull , M. L. Giroux

We have used the Westerbork Synthesis Radio Telescope to detect HI 21cm absorption at $z \sim 0.7645$ in the gravitational lens system towards PMN J0134-0931. The 21cm profile has two broad components, with peak optical depths of $0.047 \pm…

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

We measure Doppler shifts of interstellar absorption lines in HST/STIS spectra of individual star clusters in nearby UV-selected galaxies. Values for systemic velocities, which are needed to quantify outflow speeds, are taken from the…

Astrophysics · Physics 2008-11-26 C. M. Schwartz , C. L. Martin , R. Chandar , C. Leitherer , T. M. Heckman , M. S. Oey

We present 1.4 GHz HI absorption line observations towards the starburst in NGC2146, made with the VLA and MERLIN. The HI gas has a rotating disk/ring structure with column densities between 6 and 18 x 10(21) atoms cm(-2). The HI absorption…

Astrophysics · Physics 2007-05-23 A. Tarchi , A. Greve , A. B. Peck , N. Neininger , K. A. Wills , A. Pedlar , U. Klein

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

Aims. We investigate the spatial distribution of a collection of absorbing gas clouds, some associated with the dense, massive star-forming core NGC6334 I, and others with diffuse foreground clouds. For the former category, we aim to study…

Astrophysics of Galaxies · Physics 2016-09-14 M. H. D. van der Wiel , D. A. Naylor , G. Makiwa , M. Satta , A. Abergel

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…

In the preceding paper (paper I), we presented HI absorption spectra towards radio sources very close to the lines of sight towards 25 bright stars against which optical absorption spectra had been obtained earlier. In this paper we analyse…

Astrophysics · Physics 2007-05-23 Jayadev Rajagopal , G. Srinivasan , K. S. Dwarakanath

We compare predictions of large-scale cosmological hydrodynamical simulations for neutral hydrogen absorption signatures in the vicinity of 1e11 - 1e12.5 MSun haloes with observational measurements. Two different hydrodynamical techniques…

Astrophysics of Galaxies · Physics 2015-09-09 A. Meiksin , J. S. Bolton , E. R. Tittley

We report an upper limit of 9 x 10^{12} cm-2 on the column density of water in the translucent cloud along the line of sight toward HD 154368. This result is based upon a search for the C-X band of water near 1240 \AA carried out using the…

Astrophysics · Physics 2009-10-30 Marco Spaans , David Neufeld , Stephen Lepp , Gary J. Melnick , John Stauffer

Recent models of the envelopes of seven massive protostars are used to analyze observations of H3+ infrared absorption and H13CO+ submillimeter emission lines toward these stars, and to constrain the cosmic-ray ionization rate zeta. The…

Astrophysics · Physics 2007-05-23 Floris F. S. van der Tak , Ewine F. van Dishoeck

We studied a sample of 14 galaxies (0.1 < z < 0.7) using HST/WFPC2 imaging and high-resolution HST/COS or HST/STIS quasar spectroscopy of Lya, Lyb, OVI1031, and OVI1037 absorption. The galaxies, having 10.8 < log(M/M_solar) < 12.2, lie…

We present results from MUSE observations of a 21-cm HI absorption system detected with the Australian Square Kilometre Array Pathfinder radio telescope at redshift $z = 0.4503$ towards the $z = 1.71$ quasar PKS 1610-771. We identify four…

Most models identify the X-ray bright North Polar Spur (NPS) with a hot interstellar (IS) bubble in the Sco-Cen star-forming region at $\simeq$130 pc. An opposite view considers the NPS as a distant structure associated with Galactic…

Astrophysics of Galaxies · Physics 2016-11-23 R. Lallement , S. Snowden , K. D. Kuntz , T. M. Dame , D. Koutroumpa , I. Grenier , J. M. Casandjian

We address the spatial scale, ionization structure, mass and metal content of gas at the Milky Way disk-halo interface detected as absorption in the foreground of seven closely-spaced, high-latitude halo blue horizontal branch stars (BHBs)…

We present an analysis of moderately high resolution optical spectra obtained for the sight line to CD-23 13777, an O9 supergiant that probes high velocity interstellar gas associated with the supernova remnant W28. Absorption components at…

Astrophysics of Galaxies · Physics 2023-05-30 Adam M. Ritchey