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

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Observations of neutral hydrogen can provide a wealth of information about the distribution and kinematics of galaxies. To detect HI beyond the ionisation edge of galaxy disks, column density sensitivities have to be achieved that probe the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. Popping , R. Braun

This is the first in a series of three papers describing a project with the Cosmic Origins Spectrograph on the Hubble Space Telescope to measure abundances of the neutral interstellar medium (ISM) in a sample of 9 nearby star-forming…

Astrophysics of Galaxies · Physics 2015-06-22 Bethan L. James , Alessandra Aloisi , Timothy M. Heckman , Sangmo Tony Sohn , Michael A. Wolfe

Knowledge of the number density of H$\alpha$ emitting galaxies is vital for assessing the scientific impact of the Euclid and WFIRST missions. In this work we present predictions from a galaxy formation model, Galacticus, for the cumulative…

Astrophysics of Galaxies · Physics 2017-12-27 Alexander Merson , Yun Wang , Andrew Benson , Andreas Faisst , Daniel Masters , Alina Kiessling , Jason Rhodes

We use new FUSE data to determine the column densities of interstellar DI, NI, OI, FeII, and H2 along the HD41161 and HD53975 sightlines. Together with N(HI) from the literature (derived from Copernicus and IUE data) we derive D/H, N/H, and…

Astrophysics · Physics 2008-11-26 Cristina M. Oliveira , Guillaume Hebrard

We use high resolution spectra obtained with FUSE and STIS to obtain interstellar column densities of H I, D I, O I, S II, Fe II and P II toward the QSO HE 0226-4110 ( l = 253.4 deg , b = -65.77 deg). We obtain D/H = 21(+8, -6) ppm.…

Astrophysics · Physics 2009-11-13 Blair Savage , Nicolas Lehner , Andrew Fox , Bart Wakker , Kenneth Sembach

Aims. A model of heliosheath density and energy spectra of alpha-particles and He+ ions carried by the solar wind is developed. Neutralization of heliosheath He+ ions, mainly by charge exchange (CX) with neutral interstellar H and He atoms,…

Solar and Stellar Astrophysics · Physics 2014-01-08 S. Grzedzielski , P. Swaczyna , M. Bzowski

Tests of big bang nucleosynthesis and early universe cosmology require precision measurements for helium abundance determinations. However, efforts to determine the primordial helium abundance via observations of metal poor H II regions…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Erik Aver , Keith A. Olive , Evan D. Skillman

Using the nuclear symmetry energy that has been recently constrained by the isospin diffusion data in intermediate-energy heavy ion collisions, we have studied the transition density and pressure at the inner edge of neutron star crusts,…

Nuclear Theory · Physics 2014-11-20 Jun Xu , Che Ming Ko , Lie-Wen Chen , Bao-an Li , Hong-Ru Ma

We report on the abundance of interstellar neutral oxygen (OI) for 26 sightlines, using data from the Far Ultraviolet Spectroscopic Explorer (FUSE), the International Spectroscopic Explorer (IUE), and the Hubble Space Telescope (HST). OI…

Astrophysics · Physics 2009-11-10 Adam G. Jensen , Brian L. Rachford , Theodore P. Snow

We present the design and methods of the COS-Halos survey, a systematic investigation of the gaseous halos of 44 z = 0.15-0.35 galaxies using background QSOs observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope.…

We investigate data from the Galactic Effelsberg--Bonn HI Survey (EBHIS), supplemented with data from the third release of the Galactic All Sky Survey (GASS III) observed at Parkes. We explore the all sky distribution of the local Galactic…

Astrophysics of Galaxies · Physics 2016-04-27 P. M. W. Kalberla , J. Kerp , U. Haud , B. Winkel , N. Ben Bekhti , L. Floeer , D. Lenz

Almost all the physics of star formation critically depends on the number density of the molecular gas. However, the methods to estimate this key property often rely on uncertain assumptions about geometry, depend on overly simplistic…

Astrophysics of Galaxies · Physics 2025-06-04 A. Giannetti , S. Leurini , E. Schisano , V. Casasola , T. G. S. Pillai , C. Sanna , S. Ferrada-Chamorro

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…

Analysis of IBEX measurements of neutral interstellar He flux brought the inflow velocity vector different from the results of earlier analysis of observations from GAS/Ulysses. Recapitulation of results on the helium inflow direction from…

Solar and Stellar Astrophysics · Physics 2014-09-10 M. Bzowski , M. A. Kubiak , M. Hlond , J. M. Sokol , M. Banaszkiewicz , M. Witte

We calculate the planet-star flux-density ratios as a function of wavelength from 0.5 microns to 25 microns for the transiting extrasolar giant planets TrES-1 and HD209458b and compare them with the recent Spitzer/IRAC-MIPS secondary…

Astrophysics · Physics 2009-11-10 A. Burrows , I. Hubeny , D. Sudarsky

With the plethora of detailed results from heliospheric missions and at the advent of the first mission dedicated IBEX, we have entered the era of precision heliospheric studies. Interpretation of these data require precision modeling, with…

Astrophysics · Physics 2008-12-05 S. Tarnopolski , M. Bzowski

We provide the first direct observations of interstellar H+ and He+ pickup ions in the solar wind from 22 AU to 38 AU. We use the Vasyliunas and Siscoe model functional form to quantify the pickup ion distributions, and while the fit…

We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \times 10^{20}$ per cm$^{2}$; sightlines with lower HI…

Astrophysics of Galaxies · Physics 2013-02-20 Nissim Kanekar , Robert Braun , Nirupam Roy

We present an analysis of high resolution HST Space Telescope Imaging Spectrograph (STIS) observations of O I 1356 and H I Lyman-alpha absorption in 36 sight lines that probe a variety of Galactic disk environments and include paths that…

Astrophysics · Physics 2009-11-10 Stefan I. B. Cartledge , J. T. Lauroesch , David M. Meyer , Ulysses J. Sofia

We observed high S/N, high velocity resolution NH$_3$(1,1) and (2,2) emission on an extended map in TMC-1, a filamentary cloud in a nearby quiescent star forming area. By fitting multiple hyperfine-split line profiles to the NH$_3$(1,1)…

Astrophysics of Galaxies · Physics 2016-05-18 O. Fehér , L. V. Tóth , D. Ward-Thompson , J. Kirk , A. Kraus , V. -M. Pelkonen , S. Pintér , S. Zahorecz