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Related papers: Oxygen Gas Phase Abundance Revisited

200 papers

The diffuse interstellar medium (ISM) is an integral part of the evolution of the entire Galaxy. Metals are produced by stars and their abundances are the direct testimony of the history of stellar evolution. However, the interstellar dust…

Astrophysics of Galaxies · Physics 2014-03-20 C. Pinto , J. S. Kaastra , E. Costantini , C. de Vries

We use the absorption features from neutral argon at 1048 and 1066 A to determine interstellar abundances or their lower limits toward nine early-type stars. These features were observed with the Interstellar Medium Absorption Profile…

Astrophysics · Physics 2008-11-26 Ulysses J. Sofia , Edward B. Jenkins

(abridged) We present 8.2m VLT spectroscopic observations of 28 HII regions in 16 emission-line galaxies and 3.6m ESO telescope spectroscopic observations of 38 HII regions in 28 emission-line galaxies. These emission-line galaxies were…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-30 N. G. Guseva , P. Papaderos , H. T. Meyer , Y. I. Izotov , K. J. Fricke

The HyGAL Stratospheric Observatory for Infrared Astronomy (SOFIA) legacy program aims at characterizing the interstellar medium in the Milky Way using hydrides, [C II], and [O I] absorption lines with the 2.7 m SOFIA telescope toward…

We have studied the abundance of oxygen in the IGM by analyzing OVI, CIV, SiIV, and HI pixel optical depths derived from a set of high-quality VLT and Keck spectra of 17 QSOs at 2.1 < z < 3.6. Comparing OVI and CIV optical depth ratios to…

Astrophysics · Physics 2009-11-13 Anthony Aguirre , Corey Dow-Hygelund , Joop Schaye , Tom Theuns

The content of interstellar clouds, in particular the inventory of diffuse molecular gas, remains uncertain. We identified a sample of isolated clouds, approximately 100 solar masses in size, and used the dust content to estimate the total…

Astrophysics of Galaxies · Physics 2017-07-25 William T. Reach , Carl Heiles , Jean-Philippe Bernard

Observations of neutral hydrogen (HI) and molecular gas show that 50% of all nearby early-type galaxies (ETGs) contain some cold gas. Molecular gas is always found in small gas discs in the central region of the galaxy, while neutral…

Astrophysics of Galaxies · Physics 2020-04-08 M. K. Yıldız , R. F. Peletier , P. -A. Duc , P. Serra

An empirical determination of the f-values of the far-UV Mg II lines at 1239 A and 1240 A is reported. The strong near-UV Mg II lines at 2796 A and 2803 A are generally highly saturated along most interstellar sightlines outside the local…

Astrophysics · Physics 2009-10-30 Edward L. Fitzpatrick

There is a robust polyatomic chemistry in diffuse, partially-molecular interstellar gas that is readily accessible in absorption at radio/mm/sub-mm wavelengths. Accurate column densities are derived owing to the weak internal excitation, so…

Astrophysics of Galaxies · Physics 2023-02-15 Harvey Liszt , Maryvonne Gerin

A representative sample of unevolved early B-type stars in nearby OB associations and the field is analysed to unprecedented precision using NLTE techniques. The resulting chemical composition is found to be more metal-rich and much more…

Astrophysics · Physics 2009-11-13 Norbert Przybilla , Maria-Fernanda Nieva , Keith Butler

We present a reconstruction of the line-of-sight motions of the local interstellar medium (ISM) based on the combination of a model of the three-dimensional dust density distribution within 1.25 kpc from the Sun and the HI and CO line…

Hydroxyl ($\rm OH$) is known to form efficiently in cold gas ($T\sim 100$K) along with the molecule $\rm H_2$ and can be used as an efficient tracer of the diffuse molecular gas in the interstellar medium (ISM). Using a simple formalism…

Astrophysics of Galaxies · Physics 2021-04-28 Sergei Balashev , Neeraj Gupta , Daria Kosenko

We present observations of the nearby extremely metal-poor galaxy I Zw 18 using the Keck Cosmic Web Imager (KCWI) and the JWST Mid-InfraRed Instrument (MIRI) Integral Field Spectrographs (IFS). From optical and mid-IR oxygen emission lines,…

We present Keck/MOSFIRE K-band spectroscopy of the first mass-selected sample of galaxies at $z\sim2.3$. Targets are selected from the 3D-HST Treasury survey. The six detected galaxies have a mean [NII]$\lambda$6584/H$\alpha$ ratio of…

We present a new model for computing consistently the line and continuum emission from galaxies, based on a combination of recent population synthesis and photoionization codes. We use effective parameters to describe the HII regions and…

Astrophysics · Physics 2015-06-24 S. Charlot , M. Longhetti

This paper proposes a new method for estimating the total quantity of material in moving circumgalactic and intergalactic clouds from O VI measurements. We simulate high-velocity clouds (HVCs) with the FLASH hydrodynamic code and track the…

Astrophysics of Galaxies · Physics 2024-10-08 Eric Goetz , Chen Wang , Robin Shelton

We report the first detection of extended neutral hydrogen (HI) gas in the interstellar medium (ISM) of a massive elliptical galaxy beyond z~0. The observations utilize the doubly lensed images of QSO HE 0047-1756 at z_QSO = 1.676 as…

Astrophysics of Galaxies · Physics 2017-09-20 Fakhri S. Zahedy , Hsiao-Wen Chen , Michael Rauch , Ann Zabludoff

We investigate the oxygen and nitrogen abundance distributions across the optical disks of 130 nearby late-type galaxies using around 3740 published spectra of HII regions. We use these data in order to provide homogeneous abundance…

Astrophysics of Galaxies · Physics 2015-06-19 L. S. Pilyugin , E. K. Grebel , A. Y. Kniazev

We discuss the chemical properties of a sample of UV-selected intermediate-redshift (0 < z < 0.4) galaxies in the context of their physical nature and star formation history. This work represents an extension of our previous studies (Treyer…

Astrophysics · Physics 2009-11-07 T. Contini , M. A. Treyer , M. Sullivan , R. S. Ellis

We have obtained high resolution FUSE and HST/STIS echelle observations of the quasar PG 1116+215. The semi-continuous coverage of the ultraviolet spectrum over the wavelength range 916-2800 provides detections of Galactic and high velocity…

Astrophysics · Physics 2009-11-10 Rajib Ganguly , Kenneth R. Sembach , Todd M. Tripp , Blair D. Savage