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相关论文: Tracing the gas at redshift 1.7-3.5 with the Lyman…

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We present STIS 7km/s resolution data of the Ly-a forest toward PKS0405-123 (z=0.574). We make two samples. The strong sample (60 systems) has column density logNHI>13.3 over 0.002<z<0.423, and the weak sample (44) has logNHI>13.1 at…

天体物理学 · 物理学 2008-11-26 G. M. Williger , S. R. Heap , R. J. Weymann , R. Dave , E. Ellingson , R. F. Carswell , T. M. Tripp , E. B. Jenkins

Modern cosmology predicts that a galaxy overdensity is associated to a large reservoir of the intergalactic gas, which can be traced by the Ly$\alpha$ forest absorption. We have undertaken a systematic study of the relation between…

We present an analysis of the proximity effect in a sample of ten 2 A resolution QSO spectra of the Ly alpha forest at <z> = 2.9. Rather than investigating variations in the number density of individual absorption lines we employ a novel…

天体物理学 · 物理学 2009-11-07 J. Liske , G. M. Williger

We present an analysis of the evolution of the Ly alpha absorption lines in the redshift interval 0.0 to \sim 1.5 based upon a sample of 987 lines identified in the spectra of 63 QSOs obtained with the Faint Object Spectrograph on the…

We present moderate resolution data for 39 QSOs at z $\approx$ 2 obtained at the Multiple Mirror Telescope. These data are combined with spectra of comparable resolution of 60 QSOs with redshifts greater than 1.7 found in the literature to…

天体物理学 · 物理学 2009-10-31 J. Scott , J. Bechtold , A. Dobrzycki

We study the three-dimensional distribution of non virialised matter at z~2 using high resolution spectra of QSO pairs and simulated spectra drawn from cosmological hydrodynamical simulations. We have collected the largest sample of QSO…

天体物理学 · 物理学 2009-11-11 V. D'Odorico , M. Viel , F. Saitta , S. Cristiani , S. Bianchi , B. Boyle , S. Lopez , J. Maza , P. Outram

We use new observations of very weak CIV absorption lines associated with high-redshift Lyman-alpha absorption systems to measure the high-redshift Lyman-alpha line two-point correlation function (TPCF). These very weak CIV absorption lines…

天体物理学 · 物理学 2009-10-28 A. Fernandez-Soto , K. M. Lanzetta , X. Barcons , R. F. Carswell , J. K. Webb , A. Yahil

A homogeneous sample of 99 moderate resolution QSO spectra at z > 1.7 were presented in Paper I, including 39 previously unpublished spectra from the Multiple Mirror Telescope. The statistics of the Lyman alpha forest were discussed. In…

天体物理学 · 物理学 2009-10-31 J. Scott , J. Bechtold , A. Dobrzycki , V. Kulkarni

We present a method to recover the shape and amplitude of the power spectrum of mass fluctuations, P(k), from observations of the high redshift \lya forest. The method is motivated by the physical picture of the \lya forest that has emerged…

天体物理学 · 物理学 2009-10-30 Rupert A. C. Croft , David H. Weinberg , Neal Katz , Lars Hernquist

We study the distribution of low-redshift Ly$\alpha$ clouds in a CDM model using numerical simulations including photoionization and cooling of the baryonic component. The ionizing background is found to be efficient enough to keep most of…

天体物理学 · 物理学 2016-08-30 Patrick Petitjean , Jan P. Mücket , Ron Kates

We compare the low redshift (z ~ 0.1) Lyman-alpha forest from hydrodynamical simulations with data from the Cosmic Origin Spectrograph (COS). We find tension between the observed number of lines with b-parameters in the range 25-45 km/s and…

星系天体物理 · 物理学 2017-04-19 M. Viel , M. G. Haehnelt , J. S. Bolton , T. -S. Kim , E. Puchwein , F. Nasir , B. P. Wakker

We study the physical properties of the Lyman-alpha forest by applying the inversion method described by Pichon et al. (2001) to the high resolution and high S/N ratio spectrum of the z_em=2.40 quasar HE 1122-1628 obtained during Science…

天体物理学 · 物理学 2009-11-06 E. Rollinde , P. Petitjean , C. Pichon

We study the evolution with redshift, from z=5 to z=0, of the Lyman-alpha forest in a CDM model using numerical simulations including collisionless particles only. The baryonic component is assumed to follow the dark matter distribution. We…

天体物理学 · 物理学 2007-05-23 R. Riediger , P. Petitjean , J. P. Muecket

We describe a moderate-resolution (20-25 km/s) FUSE study of the low-redshift intergalactic medium. We report on studies of 7 extragalactic sightlines and 12 Ly-beta absorbers that correspond to Ly-alpha lines detected by HST/GHRS and STIS.…

The Lyman-alpha forest has opened a new redshift regime for cosmological investigation. At z > 2 it provides a unique probe of cosmic geometry and an independent constraint on dark energy that is not subject to standard candle or ruler…

天体物理学 · 物理学 2009-11-13 Andrew R. Marble , Kristoffer A. Eriksen , Chris D. Impey , Lei Bai , Lance Miller

We investigate the large-scale structure of Lyman-alpha emission intensity in the Universe at redshifts z=2-3.5 using cross-correlation techniques. Our Lya emission samples are spectra of BOSS Luminous Red Galaxies from Data Release 12 with…

宇宙学与河外天体物理 · 物理学 2018-08-29 Rupert A. C. Croft , Jordi Miralda-Escudé , Zheng Zheng , Michael Blomqvist , Matthew Pieri

We have analyzed the properties of low column density Lyman alpha forest clouds (12.8 < log N_HI < 16.0) toward 5 QSOs at different redshifts, using high signal-to-noise data from the HIRES spectrograph on the Keck I 10-m telescope. The…

天体物理学 · 物理学 2009-10-30 Tae-Sun Kim , Esther M. Hu , Lennox L. Cowie , Antoinette Songaila

Lyman $\alpha$ (Ly$\alpha$) is now routinely used as a tool for studying high-redshift galaxies and its resonant nature means it can trace neutral hydrogen around star-forming galaxies. Integral field spectrograph measurements of…

Spectra of high redshift QSOs show deep Gunn-Peterson absorptions on the blue sides of the \Lya emissions lines. They can be decomposed into components called \Lya leaks, defined to be emissive regions in complementary to otherwise…

天体物理学 · 物理学 2009-11-13 Jiren Liu , Hongguang Bi , Li-Zhi Fang

Lyman-alpha forest lines in QSO spectra have typical widths of 20-50 km/s. Low column density absorbers in cosmological simulations are large, diffuse structures, and the Hubble flow across the spatially extended absorber is usually the…

天体物理学 · 物理学 2007-05-23 David H. Weinberg , Lars Hernquist , Neal Katz , Rupert Croft , Jordi Miralda-Escudé