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We present a study of the abundances and physical conditions in the interstellar gas toward the heavily reddened star HD 192639 [E_(B-V) = 0.64], based on analysis of FUSE and HST/STIS spectra covering the range from 912 to 1361 A. This…

天体物理学 · 物理学 2009-11-07 P. Sonnentrucker , S. D. Friedman , D. E. Welty , D. G. York , T. P. Snow

As a part of the Milky Way Imaging Scroll Painting (MWISP) survey, we performed a simultaneous 12CO(1-0), 13CO(1-0), C18O(1-0) mapping toward molecular clouds in a region encompassing 3.75 square degrees. We reveal three molecular clouds,…

星系天体物理 · 物理学 2016-03-30 Y. Gong , R. Q. Mao , M. Fang , S. B. Zhang , Y. Su , J. Yang , Z. B. Jiang , Y. Xu , M. Wang , Y. Wang , D. R. Lu , J. X. Sun

In this investigation, we present an analysis of the metallicity distribution that pertains to neutral gas in the local Galactic interstellar medium (ISM). We derive relative ISM metallicities for a sample of 84 sight lines probing diffuse…

Milky Way's hot gaseous halo extends up to the Galactic virial radius ($\sim 200$ kpc) and contains a significant component of baryon mass of the Galaxy. The halo properties can be constrained from X-ray spectroscopic observations and from…

星系天体物理 · 物理学 2022-02-18 Nickolay Martynenko

Metals in the diffuse, ionized gas at the boundary between the Milky Way's interstellar medium (ISM) and circumgalactic medium (CGM), known as the disk-halo interface (DHI), are valuable tracers of the feedback processes that drive the…

We present the detection of metastable inversion lines of ammonia from energy levels high above the ground state. We detect these lines in both emission and absorption toward fifteen of seventeen positions in the central 300 parsecs of the…

星系天体物理 · 物理学 2015-06-16 Elisabeth A. C. Mills , Mark R. Morris

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…

Using Hubble Space Telescope ultraviolet and ground-based optical spectroscopy, we measure the C/O and N/O ratios of three metal-poor galaxies with similar metallicity but differing N/O. The C/O ratios estimated from C III] lambda1909 and…

天体物理学 · 物理学 2009-10-30 Henry A. Kobulnicky , Evan D. Skillman

In this paper we use observations of molecular tracers in metal rich and alpha-enhanced galaxies to study the effect of abundance changes on molecular chemistry. We selected a sample of metal rich spiral and star bursting objects from the…

宇宙学与河外天体物理 · 物理学 2015-06-15 Timothy A. Davis , Estelle Bayet , Alison Crocker , Selcuk Topal , Martin Bureau

We present UV and optical observations from the Cosmic Origins Spectrograph on the Hubble Space Telescope and Keck of a z= 0.27395 Lyman limit system (LLS) seen in absorption against the QSO PG1630+377. We detect H I absorption with log…

We present a metallicity analysis of 83 late-type giants within the central 1 pc of the Milky Way. K-band spectroscopy of these stars were obtained with the medium-spectral resolution integral-field spectrograph NIFS on Gemini North using…

ABRIDGED: Context: HI and CO large scale surveys of the Milky Way trace the diffuse atomic clouds and the dense shielded regions of molecular hydrogen clouds. However, until recently, we have not had spectrally resolved C+ surveys to…

星系天体物理 · 物理学 2015-06-18 W. D. Langer , T. Velusamy , J. L. Pineda , K. Willacy , P. F. Goldsmith

We present the detection and analysis of a weak low-ionization absorber at $z = 0.12122$ along the blazar sightline PG~$1424+240$, using spectroscopic data from both $HST$/COS and STIS. The absorber is a weak Mg II analogue, with incidence…

We present Far Ultraviolet Spectroscopic Explorer observations of the atomic and molecular absorption in high velocity cloud HVC 287.5+22.5+240, which lies in front of the ultraviolet-bright nucleus of the Seyfert 1 galaxy NGC 3783. We…

天体物理学 · 物理学 2009-10-31 Kenneth. R. Sembach , J. Christopher Howk , Blair. D. Savage , J. Michael Shull

Aims. Our aim is to confirm the interstellar detection of cyanic acid, HOCN, in the Galactic center clouds. It has previously been tentatively detected only in Sgr B2(OH). Methods. We used a complete line survey of the hot cores Sgr B2(N)…

星系天体物理 · 物理学 2015-05-19 S. Bruenken , A. Belloche , S. Martin , L. Verheyen , K. M. Menten

Very sensitive 21cm HI measurements have been made at several locations around the Local Group galaxy M31 using the Green Bank Telescope (GBT) at an angular resolution of 9.1', with a 5$\sigma$ detection level of $\rm{N_{HI} = 3.9 \times…

星系天体物理 · 物理学 2016-01-27 Spencer A. Wolfe , Felix J. Lockman , D. J. Pisano

We found that an intermediate velocity cloud (IVC) IVC 86-36 in HI 21 cm emission shows a head-tail distribution toward the Galactic plane with marked parallel filamentary streamers, which is extended over 40 degrees in the sky. The…

Multiline observations of C18O and SiO isotopomers toward 33 molecular peaks in the Galactic center region, taken at the SEST, JCMT and HHT telescopes, are presented. The C18O presumably traces the total H_2 column density, while the SiO…

天体物理学 · 物理学 2007-05-23 S. Huettemeister , G. Dahmen , R. Mauersberger , C. Henkel , T. L. Wilson , J. Martin-Pintado

We have conducted a spectral line survey observation in the 3 mm band toward the low-metallicity dwarf galaxy IC10 with the 45 m radio telescope of Nobeyama Radio Observatory to explore its chemical composition at a molecular-cloud scale…

Tantalizing evidence has been presented supporting the suggestion that a large population of extragalactic gas clouds permeates the Local Group, a population which has been associated with the Galactic High-Velocity Clouds (HVCs). We…

天体物理学 · 物理学 2007-05-23 Brad K. Gibson , Mark L. Giroux , John T. Stocke , J. Michael Shull
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