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相关论文: Detection of Ne VIII in an Intervening Multi-Phase…

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We report on the detection of two Ne VIII absorbers, at z = 0.61907 and z = 0.57052 in the HST/COS spectrum of background quasars SDSS J 080908.13+461925.6 and SBS 1122+594 respectively. The Ne VIII 770 line is at $\sim 3\sigma$…

星系天体物理 · 物理学 2018-02-06 Sachin Pachat , Anand Narayanan , Vikram Khaire , Blair D. Savage , Sowgat Muzahid , Bart P. Wakker

We report on the detection of Ne VIII in the HST/Cosmic Origins Spectrograph spectrum of the intervening absorption system at z = 0.495096 towards PKS 0405-123. The high S/N COS spectrum also covers absorption from H I, C III, O III, O IV…

We report the detection of Ne VIII in a z_abs = 0.59961 absorber towards the QSO PG 1407+265 (z_em = 0.94). Besides Ne VIII, absorption from HI Lyman series lines (HI 1025 - 915), several other low (C II, N II, O II, and S II), intermediate…

High resolution FUSE and STIS observations of the bright QSO HE 0226-4110 (zem = 0.495) reveal the presence of a multi-phase absorption line system at zabs(O VI) = 0.20701 containing absorption from H I (Ly alpha to Ly theta), C III, O III,…

天体物理学 · 物理学 2009-11-10 Blair D. Savage , Nicolas Lehner , Bart P. Wakker , Kenneth R. Sembach , Todd M. Tripp

We present HST/COS high S/N observations of the z = 0.32566 multi-phase absorber towards 3C263. The COS data shows absorption from H I, O VI, C III, N III, Si III and C II. The Ne VIII in this absorber is detected in the FUSE spectrum. The…

宇宙学与河外天体物理 · 物理学 2015-06-04 Anand Narayanan , Blair D. Savage , Bart P. Wakker

Using high resolution, high signal-to-noise ultraviolet spectra of the z = 0.9754 quasar PG1148+549 obtained with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope, we study the physical conditions and abundances of…

(Abridged) We present a sample of new population of associated absorbers, detected through Ne VIII \lambda\lambda 770,780 absorption, in HST/COS spectra of intermediate redshift (0.45 < z < 1.21) quasars (QSOs). Our sample comprised of…

宇宙学与河外天体物理 · 物理学 2013-04-30 Sowgat Muzahid , Raghunathan Srianand , Nahum Arav , Blair D Savage , Anand Narayanan

We have obtained new observations of the partial Lyman limit absorber at \zabs$=0.93$ towards quasar PG~1206+459, and revisit its chemical and physical conditions. The absorber, with $ N(HI) \sim 10^{17.0}$ ~\sqcm\ and absorption lines…

Ne VIII absorbers seen in QSO spectra are useful tracers of warm ionized gas, when collisional ionization is the dominant ionization process. While photoionization by the ultraviolet background (UVB) is a viable option, it tends to predict…

星系天体物理 · 物理学 2018-02-06 Tanvir Hussain , Vikram Khaire , Raghunathan Srianand , Sowgat Muzahid , Amit Pathak

Ultraviolet observations of the QSO 3C 263 (zem = 0.652) with COS and FUSE reveal O VI absorption systems at z = 0.06342 and 0.14072 . WIYN multi-object spectrograph observations provide information about the galaxies associated with the…

宇宙学与河外天体物理 · 物理学 2015-06-05 B. Savage , T. -S. Kim , B. Keeney , A. Narayanan , J. Stocke , B. Wakker

We present FUSE and HST/STIS observations of the absorption line system near the emission redshift of the radio-quiet, X-ray bright quasar HE0226-4110 (z = 0.495, V=15.2). The spectra cover the rest-frame wavelength range 610--1150 A, and…

天体物理学 · 物理学 2009-11-11 Rajib Ganguly , Kenneth R. Sembach , Todd M. Tripp , Blair D. Savage , Bart P. Wakker

At z<1 a large fraction of the baryons is thought to reside in diffuse gas that has been shock-heated to high temperatures (log T=5-6). Absorption by the 770.41, 780.32 {\AA} doublet of NeVIII in quasar spectra represents a unique tool to…

宇宙学与河外天体物理 · 物理学 2013-10-08 Thor Tepper-Garcia , Philipp Richter , Joop Schaye

We present a detailed analysis of a highly ionized, multiphased and collimated outflowing gas detected through O V, O VI, Ne VIII and Mg X absorption associated with the QSO HE 0238 - 1904 (z_em ~ 0.629). Based on the similarities in the…

宇宙学与河外天体物理 · 物理学 2015-06-04 Sowgat Muzahid , Raghunathan Srianand , Blair D. Savage , Anand Narayanan , Vijay Mohan , Gulab C. Dewangan

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

We explore the high spectral resolution X-ray data towards the quasar 3C273 to search for signals of hot ($\sim10^{6-7}$ K) X-ray-absorbing gas co-located with two established intergalactic FUV OVI absorbers. We analyze the soft X-ray band…

We present FUSE and STIS observations of the IGM toward PG 0953+415 (z_em = 0.239). An O VI system at z = 0.06807 is detected in H I Lya, Lyb, Lyg, O VI N V, C IV, and C III. The observations are modeled as a low density intervening gas…

天体物理学 · 物理学 2007-05-23 B. D. Savage , K. R. Sembach , T. M. Tripp , P. Richter

We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the molecular, neutral atomic, weakly ionized, and highly ionized components of the interstellar and intergalactic material toward the quasar 3C 273. We identify…

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

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

Results of a careful analysis of the highly ionized absorption systems, observed over the redshift range 2.198--2.2215 in the zem=2.24 HDFS-QSO J2233-606, are presented. Strong OVI and NeVIII absorptions are detected. Most of the lines show…

天体物理学 · 物理学 2011-05-23 Patrick Petitjean , R. Srianand

NeVIII 774 is an important tracer of the high-ionization gas in QSOs. We examine the NeVIII emission-line properties using new HST-FOS spectra of four sources, mean spectra derived from two QSO samples in the HST archives, and new…

天体物理学 · 物理学 2009-10-30 Fred Hamann , Ross D. Cohen , Joseph Shields , E. M. Burbidge , Vesa Junkkarinen , D. M. Crenshaw
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