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Observations of the QSO HE 0226-4110 (zem = 0.495) with the Cosmic Origins Spectrograph (COS) from 1134 to 1796 {\AA} with a resolution of ~17 km s-1 and signal-to- noise (S/N) per resolution element of 20 to 40 are used to study the…

宇宙学与河外天体物理 · 物理学 2015-06-03 B. Savage , N. Lehner , A. Narayanan

Westerbork Radio Synthesis Telescope observations of the redshifted 21cm line absorber against the z_em = 0.871 double lobed quasar 3C196 show that the intervening absorber is an L approximately equal L* spiral galaxy (3C196-G1) and that…

天体物理学 · 物理学 2009-11-06 F. H. Briggs , A. G. de Bruyn , R. C. Vermeulen

We present here the results of a 180 ks Chandra-LETGS observation as part of a large multi-wavelength campaign on Mrk 509. We study the warm absorber in Mrk 509 and use the data from a simultaneous HST-COS observation in order to assess…

We investigate the physical state of HI absorbing gas at low redshift (z = 0.25) using a subset of cosmological, hydrodynamic simulations from the OWLS project, focusing in particular on broad (b_HI > 40 km/s) HI Lyman-Alpha absorbers…

宇宙学与河外天体物理 · 物理学 2015-06-03 Thorsten Tepper-García , Philipp Richter , Joop Schaye , Craig M. Booth , Claudio Dalla Vecchia , Tom Theuns

We present the first grating-resolution X-ray spectra of the Seyfert 1 galaxy NGC 3783, obtained with the High Energy Transmission Grating Spectrometer on the Chandra X-ray Observatory. These spectra reveal many narrow absorption lines from…

We present results from an analysis of FUSE and HST/STIS spectroscopy of the z_em=0.57 quasar PKS0405-123. We focus on the intervening metal-line systems identified along the sightline and investigate their ionization mechanism, ionization…

We report the detection of a deep broad HI 21 cm absorption system at z = 0.78 toward the radio source [HB89] 2351+456 (4C+45.51) at z = 1.992. The HI absorption was identified in a blind spectral line survey conducted at the Green Bank…

We present MERLIN observations of Galactic 21-cm HI absorption at an angular resolution of c. 0.1-0.2 arcsec and a velocity resolution of 0.5 km/s, in the direction of three moderately low latitude (-8< b <-12 deg) extragalactic radio…

天体物理学 · 物理学 2009-11-13 W. M. Goss , A. M. S. Richards , T. W. B. Muxlow , P. Thomasson

We present HST/WFPC2 high-spatial resolution images in the R and B bands of the close environment of the sightlines to seven quasars which spectra show either a damped Ly-alpha absorption line, 21cm absorption, or a very strong MgII/FeII…

天体物理学 · 物理学 2007-05-23 V. Le Brun , J. Bergeron , P. Boisse , J. -M. Deharveng

We report observations from the Hubble Space Telescope (HST) and the VLA on the galactic environment, metallicity, and D/H in strong low-redshift Lya absorption systems toward the bright BL Lac object PKS 2155-304. GHRS/G160M spectra at 20…

We present the Green Bank Telescope absorption survey of cold atomic hydrogen ($\lesssim 300$K) in the inner halo of low-redshift galaxies. The survey aims to characterize the cold gas distribution and to address where condensation - the…

星系天体物理 · 物理学 2016-10-05 Sanchayeeta Borthakur

We present a study of the galaxy environment of 9 strong HI+CIV absorption line systems ($16.2<{\rm log}(N({\rm HI}))<21.2$) spanning a wide range in metallicity at $z\sim4-5$, using MUSE integral field and X-Shooter spectroscopic data…

We use FUSE and STIS spectra to study intergalactic absorption towards the quasar PG1259+593 (z=0.478). We identify 135 intergalactic absorption lines with equivalent widths >10mA, tracing 78 absorption components in 72 Ly alpha/beta…

天体物理学 · 物理学 2009-11-10 Philipp Richter , Blair D. Savage , Todd M. Tripp , Kenneth R. Sembach

Hot ionized gas is observed in the local vicinity of our galaxy through spectral absorption features. The most common hypothesis is that this gas forms a halo surrounding our Milky-Way (MW), in collisional ionization equilibrium. In this…

星系天体物理 · 物理学 2020-01-29 Itay Gissis , Uria Peretz , Ehud Behar

We search for highly-ionized gas near three AGN host galaxies using the Chandra low-energy transmission grating spectrograph. Strong absorption lines from such gas are seen at z=0, most likely from one or more of the following components:…

天体物理学 · 物理学 2007-09-25 Rik J. Williams , Smita Mathur , Fabrizio Nicastro

We search for weak O VI absorption in the low-redshift intergalactic medium (IGM) using 82 high signal-to-noise quasar spectra obtained with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. From this dataset, we compile…

星系天体物理 · 物理学 2025-12-12 Sapna Mishra , Vikram Khaire , Romeo Pallikkara , Anand Narayanan , Andrew J. Fox

We present our XMM-Newton RGS observations of X Comae, an AGN behind the Coma cluster. We detect absorption by NeIX and OVIII at the redshift of Coma with an equivalent width of 3.3+/-1.8 eV and 1.7+/-1.3 eV, respectively (90% confidence…

In our current galaxy formation paradigm, high-redshift galaxies are predominantly fuelled by accretion of cool, metal-poor gas from the intergalactic medium. Hydrodynamical simulations predict that this material should be observable in…

宇宙学与河外天体物理 · 物理学 2015-06-16 Neil H. M. Crighton , Joseph F. Hennawi , J. Xavier Prochaska

We study the nature of the low-redshift CGM in the Simba cosmological simulations as traced by ultraviolet absorption lines around galaxies in bins of stellar mass ($M_\star>10^{10}M_\odot$) for star-forming, green valley and quenched…

星系天体物理 · 物理学 2023-01-18 Sarah Appleby , Romeel Davé , Daniele Sorini , Weiguang Cui , Jacob Christiansen

We present a detailed analysis of the intergalactic metal-line absorption systems in the archival HST/STIS and FUSE ultraviolet spectra of the low-redshift quasar PKS1302-102 (z_QSO = 0.2784). We supplement the archive data with CLOUDY…