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Using archival, high-resolution far-ultraviolet HST/STIS spectra of 34 Galactic O and B stars, we measure CI column densities and compare them with measurements from the literature of CO and H_2 with regard to understanding the presence of…

Astrophysics of Galaxies · Physics 2014-11-20 Eric B. Burgh , Kevin France , Edward B. Jenkins

This study developed an automated identification procedure for compact clouds with broad velocity widths in the spectral line data cubes of highly crowded regions. The procedure was applied to the CO J=3-2 line data, obtained using the…

Astrophysics of Galaxies · Physics 2022-09-27 Tomoharu Oka , Asaka Uruno , Rei Enokiya , Taichi Nakamura , Yuto Yamasaki , Yuto Watanabe , Sekito Tokuyama , Yuhei Iwata

As part of the VLT/X-shooter science verification, we obtained the first optical medium-resolution spectrum of a previously identified bright O-type object in NGC55, an LMC-like galaxy at a distance of \sim2.0 Mpc. Based on the stellar and…

Solar and Stellar Astrophysics · Physics 2013-01-17 Olga Hartoog , Hugues Sana , Alex de Koter , Lex Kaper

We present the results from our search for C IV in the intergalactic medium at redshifts z=5.3-6.0. We have observed four z~6 QSOs with Keck/NIRSPEC in echelle mode. The data are the most sensitive yet taken to search for C IV at these…

Astrophysics · Physics 2011-02-11 George D. Becker , Michael Rauch , Wallace L. W. Sargent

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

We have mapped 11 compact high-velocity clouds (CHVCs) in the 21-cm line emission of neutral, atomic hydrogen, using the Effelsberg 100-m radio telescope. The aim of our observations was to study the overall distribution of the warm neutral…

Astrophysics · Physics 2009-11-10 T. Westmeier , C. Bruens , J. Kerp

Although measuring the gas metallicity in galaxies at various redshifts is crucial to constrain galaxy evolutionary scenarios, only rest-frame optical emission lines have been generally used to measure the metallicity. This has prevented us…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Tohru Nagao , Roberto Maiolino , Alessandro Marconi , Hideo Matsuhara

We report results from the third in a series of nebular abundance studies of emission-line galaxies from the KPNO International Spectroscopic Survey (KISS). Galaxies with coarse metallicity estimates of 12 + log(O/H) less than 8.2 dex were…

Astrophysics · Physics 2009-11-10 Janice C. Lee , John J. Salzer , Jason Melbourne

We report the discovery of molecular hydrogen absorption in a Galactic high-velocity cloud (HVC) in the direction of the Large Magellanic Cloud. For the same HVC we derive an iron abundance which is half of the solar value. Thus, all…

Astrophysics · Physics 2009-10-31 P. Richter , K. S. de Boer , H. Widmann , N. Kappelmann , W. Gringel , M. Grewing , J. Barnstedt

The heating and cooling of the interstellar medium allow the gas in the ISM to coexist at very different temperatures in thermal pressure equilibrium. The heating cannot be directly determined, but the cooling can be inferred from…

Astrophysics · Physics 2009-11-10 N. Lehner , B. P. Wakker , B. D. Savage

Neutral hydrogen mapping of several small, very low column density High Velocity Clouds (HVC), using the Arecibo telescope, is reported. Some were found serendipitously superimposed at distinct velocities on largerHVCs; others were found to…

Astrophysics · Physics 2009-11-10 G. Lyle Hoffman , E. E. Salpeter , Ajay Hirani

We present a census of neutral gas in the Milky Way disk and halo down to limiting column densities of $N$(HI)$\sim10^{14}$ cm$^{-2}$ using measurements of HI Lyman-series absorption from the Far Ultraviolet Spectroscopic Explorer (FUSE).…

Compact high-velocity clouds (CHVCs) are the most distant of the HVCs in the Local Group model and would have HI volume densities of order 0.0003/cm^3. Clouds with these volume densities and the observed neutral hydrogen column densities…

Astrophysics · Physics 2009-11-07 Philip R. Maloney , Mary E. Putman

The Interstellar Medium (ISM) comprises gases at different temperatures and densities, including ionized, atomic, molecular species, and dust particles. The neutral ISM is dominated by neutral hydrogen and has ionization fractions up to 8%.…

The recent detection of dust emission in Complex C, the largest High-Velocity Cloud (HVC) on the sky, opens a very interesting perspective for Planck. The HVC dust temperature determined using IRAS and Spitzer observations is low (T~10.7 K)…

(Abbreviated) From six spectra of high-z QSOs, we select eleven metal-rich, Z>=Z_solar, and optically-thin to the ionizing radiation, N(HI)<10^17 cm^-2, absorption systems ranging between z=1.5 and z=2.9 and revealing lines of different…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 S. A. Levshakov , I. I. Agafonova , P. Molaro , D. Reimers , J. L. Hou

We present mid-infrared ISO-SWS observations of the fine-structure emissions lines [NeII]12.8, [NeIII]15.6, [NeIII]36, [ArII]6.9, [ArIII]8.9, [SIII]18.7, [SIII]33.5, [SIV]10.5, and the recombination lines Br_alpha and Br_beta, in a sample…

Astrophysics · Physics 2009-11-07 Uriel Giveon , Amiel Sternberg , Dieter Lutz , Helmut Feuchtgruber , Adi Pauldrach

To explore the origin of high-velocity gas in the direction of the Large Magellanic Cloud (LMC) we analyze absorption lines in the ultraviolet spectrum of a Galactic halo star that is located in front of the LMC at d=9.2 kpc distance. We…

Astrophysics of Galaxies · Physics 2015-11-18 P. Richter , K. S. de Boer , K. Werner , T. Rauch

We report the first high spectral resolution study of 17 M giants kinematically confirmed to lie within a few parsecs of the Galactic Center, using R=24,000 spectroscopy from Keck/NIRSPEC and a new linelist for the infrared K band. We…

Astrophysics of Galaxies · Physics 2017-11-29 R. M. Rich , N. Ryde , B. Thorsbro , T. K. Fritz , M. Schultheis , L. Origlia , H. Jönsson

We present deep echelle spectrophotometry of the brightest emission-line knots of the star-forming galaxies He 2-10, Mkn 1271, NGC 3125, NGC 5408, POX 4, SDSS J1253-0312, Tol 1457-262, Tol 1924-416 and the HII region Hubble V in the Local…

Astrophysics of Galaxies · Physics 2015-06-22 C. Esteban , J. García-Rojas , L. Carigi , M. Peimbert , F. Bresolin , A. R. López-Sánchez , A. Mesa-Delgado