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相关论文: H3+ in Diffuse Interstellar Clouds: a Tracer for t…

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As a complement to the HyGAL Stratospheric Observatory for Infrared Astronomy Legacy Program, we report the results of a ground-based absorption line survey of simple molecules in diffuse and translucent Galactic clouds. Using the Institut…

We present high S/N measurements of the H I Ly alpha absorption line toward 16 Galactic targets which are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove…

星系天体物理 · 物理学 2023-04-05 S. D. Friedman , P. Chayer , E. B. Jenkins , T. M. Tripp , G. M. Williger , G. Hebrard , P. Sonnentrucker

Yamamoto et al. (1987) reported the first detection of $c$-C$_3$H radical in {TMC-1} through its transition $2_{1 2} \to 1_{1 1}$ at 91.5 GHz. Mangum and Wootten (1990) detected $c$-C$_3$H through the transition $1_{1 0} \to 1_{1 1}$ at…

天体物理学 · 物理学 2007-05-23 Suresh Chandra , S. A. Shinde

We present Jansky Very Large Array observations of 20 - 37 GHz absorption lines from nearby Galactic diffuse molecular gas seen against four cosmologically-distant compact radio continuum sources. The main new observational results are that…

星系天体物理 · 物理学 2018-04-18 Harvey Liszt , Maryvonne Gerin , Anthony Beasley , Jerome Pety

The submillimeter opacity of dust in the diffuse Galactic interstellar medium (ISM) has been quantified using a pixel-by-pixel correlation of images of continuum emission with a proxy for column density. We used three BLAST bands at 250,…

We present experimental results obtained from photoionization and photodissociation processes of abundant interstellar methanol (CH$_3$OH) as an alternative route for the production of H$_3^+$ in dense clouds. The measurements were taken at…

天体物理学 · 物理学 2009-11-13 S. Pilling , D. P. P. Andrade , A. C. F. Santos , H. M. Boechat-Roberty

Observations of the emission of the carbon cycle species (C, C+ CO) are commonly used to diagnose gas properties in the interstellar medium but are significantly sensitive to the cosmic-ray ionization rate. The carbon-cycle chemistry is…

星系天体物理 · 物理学 2022-03-14 Brandt A. L. Gaches , Thomas G. Bisbas , Shmuel Bialy

Observations of CO+ suggest column densities on the order 10^12 cm^-2 that can not be reproduced by many chemical models. CO+ is more likely to be destroyed than excited in collisions with hydrogen. An anomalous excitation mechanism may…

太阳与恒星天体物理 · 物理学 2015-05-13 Pascal Staeuber , Simon Bruderer

We present direct measures of the ionization fractions of several sulfur ions in the Galactic warm ionized medium (WIM). We obtained high resolution ultraviolet absorption line spectroscopy of post-asymptotic giant branch stars in the the…

星系天体物理 · 物理学 2015-06-11 J. Christopher Howk , S. Michelle Consiglio

We present a detailed study of the hydrogen density distribution in the local interstellar medium (ISM) using the X-ray absorption technique. Hydrogen column densities were precisely measured by fitting X-ray spectra from coronal sources…

高能天体物理现象 · 物理学 2024-08-28 E. Gatuzz , J. Wilms , A. Zainab , S. Freund , P. C. Schneider , J. Robrade , S. Czesla , J. A. García , T. R. Kallmanınst

The Atacama Pathfinder Experiment (APEX) 12m telescope was used to observe the N=1-0, J=0-1 ground state transitions of OH+ at 909.1588 GHz with the CHAMP+ heterodyne array receiver. Two blended hyperfine structure transitions were detected…

星系天体物理 · 物理学 2015-05-18 F. Wyrowski , K. M. Menten , R. Guesten , A. Belloche

This paper provides a general reference for deriving the ionizations and metal abundances for absorption-line clouds in photoionization equilibrium with a QSO spectrum. The results include a quantitative assessment of the theoretical…

天体物理学 · 物理学 2009-10-30 Fred Hamann

We report the first observation of the vertical and temporal structure of the H3+ emission at the auroral footprint of Io, as observed by Juno/JIRAM. The brightness vertical profile shows a maximum at 600 km above 1 bar, with no apparent…

地球与行星天体物理 · 物理学 2024-10-29 A. Mura , A. Moirano , V. Hue , C. Castagnoli , A. Migliorini , A. Altieri , A. Adriani , A. Cicchetti , C. Plainaki , G. Piccioni , R. Noschese , G. Sindoni , R. Sordini

We report the first detection of C$^{15}$N in diffuse molecular gas from a detailed examination of CN absorption lines in archival VLT/UVES spectra of stars probing local diffuse clouds. Absorption from the C$^{15}$N isotopologue is…

星系天体物理 · 物理学 2018-06-07 Adam M. Ritchey , Steven R. Federman , David L. Lambert

We discuss the possibility of mapping interstellar clouds at unprecedentedly high spatial resolution by means of near-IR imaging of their scattered light. We calculate the scattering of the interstellar radiation field by a cloud model…

天体物理学 · 物理学 2009-11-13 Paolo Padoan , Mika Juvela , Veli-Matti Pelkonen

We present a neutral hydrogen-selected absorption-line survey of gas with HI column densities 15<log N(HI)<19 at z<1 using the Cosmic Origins Spectrograph on the Hubble Space Telescope. Our main aim is to determine the metallicity…

We present interstellar C II (1334.5323 \AA) and C II* (1335.7077 \AA) column density measurements along 14 Galactic sight-lines. These sight-lines sample a variety of Galactic disk environments and include paths that range nearly two…

星系天体物理 · 物理学 2011-02-18 Veena S. Parvathi , Ulysses J. Sofia , Jayant Murthy , B. R. S. Babu

We investigate the correlation between OH and H2 column densities in diffuse Galactic clouds, in order to identify potential molecular tracers of interstellar H2. For this, we analyse near-UV spectra extracted from the ESO/VLT archives…

星系天体物理 · 物理学 2023-06-09 Katherine Rawlins , Bhaswati Mookerjea

Aims. The HIFI instrument onboard Herschel has allowed high spectral resolution and sensitive observations of ground-state transi- tions of three molecular ions: the methylidyne cation CH+, its isotopologue 13CH+, and sulfanylium SH+.…

Infrared Dark Clouds are expected to harbor sources in different, very young evolutionary stages. To better characterize these differences, we observed a sample of 43 massive Infrared Dark Clouds, originally selected as candidate high-mass…

天体物理学 · 物理学 2019-08-19 H. Beuther , T. K. Sridharan