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相关论文: Bimodality of low-redshift circumgalactic O VI in …

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We explore the circumgalactic metal content traced by commonly observed low ion absorbers, including C II, Si II, Si III, Si IV, and Mg II. We use a set of cosmological hydrodynamical zoom simulations run with the EAGLE model and including…

星系天体物理 · 物理学 2018-08-29 Benjamin D. Oppenheimer , Joop Schaye , Robert A. Crain , Jessica K. Werk , Alexander J. Richings

Far Ultraviolet Spectroscopic Explorer spectra of 22 Galactic halo stars are studied to determine the amount of O VI in the Galactic halo between ~0.3 and \~10 kpc from the Galactic mid-plane. Strong O VI 1031.93 A absorption was detected…

天体物理学 · 物理学 2009-11-07 J. Zsargo , K. R. Sembach , J. C. Howk , B. D. Savage

We use the EAGLE (Evolution and Assembly of GaLaxies and their Environments) cosmological simulation to study the distribution of baryons, and far-ultraviolet (O VI), extreme-ultraviolet (Ne VIII) and X-ray (O VII, O VIII, Ne IX, and Fe…

星系天体物理 · 物理学 2020-09-07 Nastasha A. Wijers , Joop Schaye , Benjamin D. Oppenheimer

A search for O VI at redshifts corresponding to Ly-alpha lines in the z_em ~ 2.4 QSOs HE1122-1648 and HE2217-2818 reveals that a substantial fraction of those with H I column densities log N(HI) > 14 (cm^{-2}) are highly ionized and show…

天体物理学 · 物理学 2009-11-07 Robert F. Carswell , Joop Schaye , Tae-Sun Kim

We use the EAGLE cosmological, hydrodynamical simulations to predict the column density and equivalent width distributions of intergalactic O VII ($E=574$ eV) and O VIII ($E=654$ eV) absorbers at low redshift. These two ions are predicted…

星系天体物理 · 物理学 2019-07-10 Nastasha A. Wijers , Joop Schaye , Benjamin D. Oppenheimer , Robert A. Crain , Fabrizio Nicastro

We explore the abundance, spatial distribution, and physical properties of the OVI, OVII, and OVIII ions of oxygen in circumgalactic and intergalactic media (the CGM, IGM, and WHIM). We use the TNG100 and TNG300 large volume cosmological…

We used FUSE to observe ultraviolet emission from diffuse O VI in the hot gas in the Galactic halo. By comparing our result with another, nearby observation blocked by an opaque cloud at a distance of 230 pc, we could subtract off the…

天体物理学 · 物理学 2011-02-11 Robin L. Shelton , Shauna M. Sallmen , Edward B. Jenkins

Proximity zone fossils (PZFs) are ionization signatures around recently active galactic nuclei (AGN) where metal species in the circumgalactic medium remain over-ionized after the AGN has shut-off due to their long recombination timescales.…

星系天体物理 · 物理学 2018-04-13 Benjamin D. Oppenheimer , Marijke Segers , Joop Schaye , Alexander J. Richings , Robert A. Crain

We study the hot and cold circum-galactic medium (CGM) of 86 galaxies of the cosmological, hydrodynamical simulation suite NIHAO. NIHAO allows a study of how the $z=0$ CGM varies across 5 orders of magnitude of stellar mass using OVI and HI…

星系天体物理 · 物理学 2016-10-19 Thales A. Gutcke , Greg S. Stinson , Andrea V. Macciò , Liang Wang , Aaron A. Dutton

The galactic gaseous halo is a gas reservoir for the interstellar medium in the galaxy disk, supplying materials for star formation. We developed a gaseous halo model connecting the galaxy disk and the gaseous halo by assuming the star…

星系天体物理 · 物理学 2018-04-04 Zhijie Qu , Joel N. Bregman

The total contribution of diffuse halo gas to the galaxy baryon budget strongly depends on its dominant ionization state. In this paper, we address the physical conditions in the highly ionized circumgalactic medium (CGM) traced by OVI…

O VI absorption is observed in a wide range of astrophysical environments, including the Local ISM, the disk and halo of the Milky Way, high-velocity clouds, the Magellanic clouds, starburst galaxies, the intergalactic medium, damped…

宇宙学与河外天体物理 · 物理学 2015-05-27 Andrew J. Fox

We report Far Ultraviolet Spectroscopic Explorer (FUSE) observations of interstellar O VI absorption in the halo of the Milky Way towards 12 early-type stars in the Large Magellanic Cloud (LMC) and 11 in the Small Magellanic Cloud (SMC).…

天体物理学 · 物理学 2007-05-23 J. Christopher Howk , Blair D. Savage , Kenneth R. Sembach , Charles G. Hoopes

We consider evolution of metal-enriched gas exposed to a superposition of time-dependent radiation field of a nearby starburst galaxy and nearly invariant (on timescales 100 Myr) extragalactic ionization background. Within nonequilibrium…

星系天体物理 · 物理学 2018-02-06 E. O. Vasiliev , M. V. Ryabova , Yu. A. Shchekinov

Galaxies are surrounded by extended gaseous halos which store significant fractions of chemical elements. These are syntethized by the stellar populations and later ejected into the circumgalactic medium (CGM) by different mechanism, of…

星系天体物理 · 物理学 2018-01-10 Rubens E. G. Machado , Patricia B. Tissera , Gastão B. Lima Neto , Laerte Sodré

In order to determine if the material ablated from high-velocity clouds (HVCs) is a significant source of low-velocity high ions (C IV, N V, and O VI) such as those found in the Galactic halo, we simulate the hydrodynamics of the gas and…

星系天体物理 · 物理学 2015-06-04 David B. Henley , Kyujin Kwak , Robin L. Shelton

Observations reveal massive amounts of OVI around star-forming $L_*$ galaxies, with covering fractions of near unity extending to the host halo's virial radius. This OVI absorption is typically kinematically centered upon photoionized gas,…

星系天体物理 · 物理学 2018-07-12 Matthew McQuinn , Jessica K. Werk

We present a unified analysis of the O{\sc vi} absorption-lines seen in the disk and halo of the Milky Way, high velocity clouds, the Magellanic Clouds, starburst galaxies, and the intergalactic medium. We show that these disparate systems…

天体物理学 · 物理学 2009-11-07 T. M. Heckman , C. A. Norman , D. K. Strickland , K. R. Sembach

We study the components of cool and warm/hot gas in the circumgalactic medium (CGM) of simulated galaxies and address the relative production of OVI by photoionization versus collisional ionization, as a function of halo mass, redshift, and…

We present observations of the O VI system at z_abs = 0.495096 toward PKS 0405-123 (z_em = 0.5726) obtained with FUSE and STIS. In addition to strong O VI, with log N(O VI) = 14.47+/-0.02, and moderate H I this absorber shows C III, N IV, O…

宇宙学与河外天体物理 · 物理学 2009-03-25 J. Christopher Howk , Joseph S. Ribaudo , Nicolas Lehner , J. Xavier Prochaska , Hsiao-Wen Chen
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