English
Related papers

Related papers: Neutral H density at the termination shock: a cons…

200 papers

We present a measurement of the deuterium to hydrogen ratio (D/H) in a metal-poor absorption system at redshift $z=2.504$ towards the QSO 1009+2956. We apply the new method of Burles & Tytler (1997) to robustly determine D/H in high…

Astrophysics · Physics 2008-11-26 Scott Burles , David Tytler

We present a comparison of the gas and dust properties of the dense interstellar matter in six nearby star-forming regions (d<500 pc): rho Oph, Cha I, R CrA, IC 348, NGC 1333, and Orion. We measure from Chandra and XMM-Newton observations…

We present a detailed study of an estimator of the HI column density, based on a combination of HI 21cm absorption and HI 21cm emission spectroscopy. This "isothermal" estimate is given by $N_{\rm HI,ISO} = 1.823 \times 10^{18} \int \left[…

Astrophysics of Galaxies · Physics 2014-07-30 Jayaram N. Chengalur , Nissim Kanekar , Nirupam Roy

We present measurements of the dust attenuation of H\alpha-selected emission-line galaxies at z=0.8 from the NewH\alpha\ narrowband survey. The analysis is based on deep follow-up spectroscopy with Magellan/IMACS, which captures the strong…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ivelina Momcheva , Janice C. Lee , Chun Ly , Samir Salim , Daniel A. Dale , Masami Ouchi , Rose Finn , Yoshiaki Ono

Interstellar neutral (ISN) hydrogen is the most abundant species in the outer heliosheath and the very local interstellar medium (VLISM). Charge exchange collisions in the outer heliosheath result in filtration, reducing the ISN hydrogen…

We have carried out a sensitive high-latitude (|b| > 15deg.) HI 21cm-line absorption survey towards 102 sources using the GMRT. With a 3-sigma detection limit in optical depth of ~0.01, this is the most sensitive HI absorption survey. We…

Astrophysics · Physics 2009-11-10 Rekhesh Mohan , K. S. Dwarakanath , G. Srinivasan

A model is proposed for determining the distances to falling interstellar clouds in the galactic halo by measuring the cloud velocity and column density and assuming a model for the vertical density distribution of the Galactic interstellar…

Astrophysics · Physics 2009-10-28 Robert A. Benjamin , Laura Danly

We report results from a FUSE survey of interstellar molecular hydrogen (H2) in the Galactic disk toward 139 O-type and early B-type stars at Galactic latitudes $|b| < 10^{\circ}$, with updated photometric and parallax distances. The H2…

Astrophysics of Galaxies · Physics 2021-04-21 J. Michael Shull , Charles W. Danforth , Katherine L. Anderson

A new dataset of atomic oxygen and molecular nitrogen number density profiles, along with thermospheric temperature profiles between 180 and 500 km, has been developed. These profiles are derived from solar occultation measurements made by…

We report the results of initial FUSE observations of molecular hydrogen (H2) in translucent clouds. These clouds have greater optical depth than any of the diffuse clouds previously observed for far-UV H2 absorption, and provide new…

Obtaining a complete census of gas in the local interstellar medium (<100 pc) is challenging given the limited available tracers of the warm, partially-ionized medium. Medium-to-high resolution UV absorption spectroscopy toward individual…

Context: Reconnaissance of feasibility of detection of interstellar neutral D by the forthcoming NASA SMEX mission IBEX. Aims: To investigate by numerical simulations the absolute density and flux at Earth orbit of neutral interstellar D…

Astrophysics · Physics 2009-11-13 S. Tarnopolski , M. Bzowski

Based on the analysis of available published data and archival data along 24 sightlines (5 of which are new) we derive more accurate estimates of the column densities of OH and CH towards diffuse/translucent clouds and revisit the typically…

Astrophysics of Galaxies · Physics 2016-04-20 Bhaswati Mookerjea

We report interstellar C II column densities or upper limits determined from weak absorption of the 2325.4029 A intersystem transition observed in six translucent sightlines with STIS. The sightlines sample a wide range of interstellar…

Astrophysics · Physics 2009-11-10 U. J. Sofia , J. T. Lauroesch , D. M. Meyer , S. I. B. Cartledge

We discuss the interstellar absorption from many atomic and molecular species seen in high-resolution $HST$/STIS UV and high-S/N optical spectra of the moderately reddened B3-5~V star HD~62542. This remarkable sight line exhibits both very…

Astrophysics of Galaxies · Physics 2020-07-08 Daniel E. Welty , Paule Sonnentrucker , Theodore P. Snow , Donald G. York

UV absorption studies with FUSE have observed H2 molecular gas in translucent and diffuse clouds. Observations of the 158 micron [C II] fine structure line with Herschel also trace the same H2 molecular gas in emission. We present [C II]…

Astrophysics of Galaxies · Physics 2017-04-12 Thangasamy Velusamy , William Langer , Paul Goldsmith , Jorge L. Pineda

AIMS. We derive the morphology of the stellar component in the outer halo volume, and search for possible overdensities due to substructures therein. METHODS. We made use of some of the data releases of the spectroscopic survey LAMOST…

Astrophysics of Galaxies · Physics 2024-02-09 M. Lopez-Corredoira , X. -C. Tang , H. Tian , H. -F. Wang , G. Carraro , C. Liu

The relation between ices in the envelopes and disks surrounding YSOs and those in the quiescent interstellar medium is investigated. For a sample of 31 stars behind isolated dense cores, ground-based and Spitzer spectra and photometry in…

H I stacking has proven to be a highly effective tool to statistically analyse average H I properties for samples of galaxies which may or may not be directly detected. With the plethora of H I data expected from the various upcoming H I…

Astrophysics of Galaxies · Physics 2019-08-02 J. Healy , S-L. Blyth , E. Elson , W. van Driel , Z. Butcher , S. Schneider , M. D. Lehnert , R. Minchin

The thermodynamic parameters like energy density, pressure, entropy density, temperature and particle density are determined from the transverse momentum distributions of charged particles in Pb-Pb collisions at the LHC. The results show a…

High Energy Physics - Phenomenology · Physics 2020-04-22 M. D. Azmi , T. Bhattacharyya , J. Cleymans , M. Paradza