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Related papers: Systematic Continuum Errors in the Lyman-Alpha For…

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This is the first measurement and detection of coherence in the intergalactic medium (IGM) at substantially high redshift (z~3.8) and on large physical scales (~2.5 h^-1 Mpc). We perform the measurement by presenting new observations from…

We investigate the dependence of QSO Lyman-alpha absorption features on the temperature of the absorbing gas and on the amplitude of the underlying dark matter fluctuations. We use high-resolution hydrodynamic simulations in cold dark…

Astrophysics · Physics 2009-10-31 Tom Theuns , Joop Schaye , Martin Haehnelt

Lyman-$\alpha$ (Ly$\alpha$) spectra provide insights into the small-scale structure and kinematics of neutral hydrogen (HI) within galaxies as well as the ionization state of the intergalactic medium (IGM). The former defines the intrinsic…

Astrophysics of Galaxies · Physics 2020-10-21 Chris Byrohl , Max Gronke

Evolution of the cluster temperature function is extremely sensitive to the mean matter density of the universe. Current measurements based on cluster temperature surveys indicate that Omega_M ~ 0.3 with a 1-sigma statistical error ~0.1,…

Astrophysics · Physics 2009-10-31 G. M. Voit

We investigate Lyman-alpha forest flux statistics in mixed fuzzy dark matter (FDM) and cold dark matter (CDM) cosmologies using the Fluctuating Gunn-Peterson Approximation (FGPA) applied to hybrid Schr\"odinger-Poisson and N-body…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Yourong Frank Wang

We show that the Lyman-alpha optical depth statistics in the proximity regions of quasar spectra depend on the mass of the dark matter halos hosting the quasars. This is owing to both the overdensity around the quasars and the associated…

Astrophysics · Physics 2009-11-13 C. -A. Faucher-Giguere , A. Lidz , M. Zaldarriaga , L. Hernquist

We present some statistical features of the large number of \lya absorption lines detected in high redshift quasar spectra, obtained by using the multifractal approach. In the analysed sample of 12 QSO sight--lines, 11 show scaling…

Astrophysics · Physics 2007-05-23 S. Savaglio , V. Carbone

Our goal in this paper is to test some popular dark matter models by Ly-alpha forest in QSO spectra. Recent observations of the size and velocity of Ly-alpha forest clouds have indicated that the Ly-alpha absorption is probably not given by…

Astrophysics · Physics 2009-10-28 Hongguang BI , Jian GE , Li-Zhi FANG

The thermal emission of dust is one of the most important tracers of the interstellar medium: multi-wavelength photometry in the far-infrared (FIR) and submillimeter (submm) can be fitted with a model, providing estimates of the dust mass.…

Astrophysics of Galaxies · Physics 2020-10-07 Lapo Fanciullo , Francisca Kemper , Peter Scicluna , Thavisha E. Dharmawardena , Sundar Srinivasan

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…

Astrophysics · Physics 2009-10-31 J. Scott , J. Bechtold , A. Dobrzycki

The properties of the Lyman-$\alpha$ absorptions observed in the spectra of QSOs are reviewed: the distribution of column densities and Doppler widths, the redshift evolution, the ``inverse effect'', the clustering. By interpreting the…

Astrophysics · Physics 2007-05-23 S. Cristiani

We study the effect of different feedback prescriptions on the properties of the low redshift ($z\leq1.6$) Ly$\alpha$ forest using a selection of hydrodynamical simulations drawn from the Sherwood simulation suite. The simulations…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Fahad Nasir , James S. Bolton , Matteo Viel , Tae-Sun Kim , Martin G. Haehnelt , Ewald Puchwein , Debora Sijacki

The thermal state of the intergalactic medium (IGM) at z < 6 constrains the nature and timing of cosmic reionization events, but its inference from the Ly-alpha forest is degenerate with the 3-D structure of the IGM on ~100 kpc scales,…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-14 Girish Kulkarni , Joseph F. Hennawi , Jose Oñorbe , Alberto Rorai , Volker Springel

Systematic inaccuracy is inherent in any computational estimate of a non-linear average, such as the free energy difference (Delta-F) between two states or systems, because of the availability of only a finite number of data values, N. In…

Computational Physics · Physics 2007-05-23 Daniel M. Zuckerman , Thomas B. Woolf

We consider the impact of quasar outflows on structure formation. Such outflows are potentially more important than galactic winds, which appear insufficient to produce the level of preheating inferred from X-ray observations of galaxy…

Astrophysics · Physics 2011-07-18 Evan Scannapieco , S. Peng Oh

We present observations of the Lyman alpha forest towards B2 1225+317 taken at a resolution of 18 km/s. A clean sample of Lyman alpha forest lines is extracted after a careful profile fitting analysis and removal of absorption lines of…

Astrophysics · Physics 2015-06-24 Pushpa Khare , R. Srianand , D. G. York , R. Green , D. Welty , Ke-Liang Huang , J. Bechtold

Recent analyses of the intergalactic UV background by means of the HeII Lyman alpha forest assume that HeII and HI absorption features have the same line widths. We omit this assumption to investigate possible effects of thermal line…

Astrophysics · Physics 2009-11-11 C. Fechner , D. Reimers

We propose a tree-level biomass estimation model approximating allometric equations by LiDAR data. Since tree crown diameters estimation is challenging from spaceborne LiDAR measurements, we develop a model to correlate tree height with…

Applications · Statistics 2023-05-18 Qian Song , Conrad M Albrecht , Zhitong Xiong , Xiao Xiang Zhu

We study the clustering of matter in the intergalactic medium from the Lyman-alpha forests seen in the spectra of pairs or groups of z ~ 2 quasars observed with FORS2 and UVES at the VLT-UT2 Kueyen ESO telescope. The sample consists of five…

Astrophysics · Physics 2009-11-07 E. Rollinde , P. Petitjean , C. Pichon , S. Colombi , B. Aracil , V. D'Odorico , M. G. Haehnelt