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The correlation between Lyman-alpha absorption in the spectra of quasar pairs can be used to measure the transverse distance scale at z~2, which is sensitive to the cosmological constant (Omega_Lambda) or other forms of vacuum energy. Using…

Astrophysics · Physics 2009-11-07 Patrick McDonald

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…

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

Recent measurements of the autocorrelation function of the Ly-alpha clouds are analyzed from the point of view of a simple model with strong clustering on the small scales. It is shown that this toy model reproduces fairly well the…

Astrophysics · Physics 2009-10-31 Milan M. Cirkovic , Kenneth M. Lanzetta

We present the results of our study on three close pairs of QSOs. Our results are consistent with the existence of a proximity effect due to the foreground QSO, but due to its weakness we can only reject the absence of such effect at…

Astrophysics · Physics 2007-05-23 A. Fernandez-Soto , X. Barcons , R. Carballo , J. K. Webb

While the Lyman-$\alpha$ (Ly$\alpha$) forest traces the large-scale matter distribution over a wide range of redshift, its three-dimensional (3D) clustering at $z < 2$ has not yet been measured. We investigate the prospects for measuring…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Ting Tan , Huanyuan Shan , Eric Armengaud

Context. One important step in the statistical analysis of the Ly-alpha forest data is the study of their second order properties. Usually, this is accomplished by means of the two-point correlation function or, alternatively, the…

Astrophysics · Physics 2009-11-13 R. Vio , V. D'Odorico , H. Stoyan , D. Stoyan

The Lyman-alpha forest is the large-scale structure probe for which we appear to have modeling control to the highest wavenumbers. This makes the Lyman-alpha forest of great interest for constraining the warmness/fuzziness of dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-27 Bayu Wilson , Vid Iršič , Matthew McQuinn

We present a new technique for detecting structure on Mpc scales in the Lyman-alpha forest. The technique is easy to apply in practice since it does not involve absorption line fitting but is rather based on the statistics of the…

Astrophysics · Physics 2009-10-30 J. Liske , J. K. Webb , R. F. Carswell

We present the calculation of the Lyman-alpha (Lyman-$\alpha$) transmitted flux fluctuations with full relativistic corrections to the first order. Even though several studies exist on relativistic effects in galaxy clustering, this is the…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-24 Vid Iršič , Enea Di Dio , Matteo Viel

The spatial distribution of Ly-alpha forest absorption systems towards ten QSOs has been analysed to search for large-scale structure over the redshift range 2.2 < z < 3.4. The QSOs form a closely spaced group on the sky and are…

Astrophysics · Physics 2009-10-31 J. Liske , J. K. Webb , G. M. Williger , A. Fernandez-Soto , R. F. Carswell

We present the first detection of a correlation between the Lyman-$\alpha$ forest and cosmic microwave background (CMB) lensing. For each Lyman-$\alpha$ forest in SDSS-III/BOSS DR12, we correlate the one-dimensional power spectrum with the…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-15 Cyrille Doux , Emmanuel Schaan , Eric Aubourg , Ken Ganga , Khee-Gan Lee , David N. Spergel , Julien Tréguer

We have studied the possibility of measuring the cross-correlation of the redshifted HI 21-cm signal and the Lyman-$\alpha$ forest using an upcoming radio-interferometric array OWFA and an spectroscopic observation like SDSS-IV. Our results…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Anjan Kumar Sarkar , Somnath Bharadwaj , Tapomoy Guha Sarkar

We measure the large-scale cross-correlation of quasars with the Lyman \alpha\ forest absorption in redshift space, using ~ 60000 quasar spectra from Data Release 9 (DR9) of the Baryon Oscillation Spectroscopic Survey (BOSS). The…

We present a new measure of the angular two-point correlation function of Lyman-break galaxies (LBGs) at z~3, obtained from the variance of galaxy counts in 2-dimensional cells. By avoiding binning of the angular separations, this method is…

Astrophysics · Physics 2009-11-06 Cristiano Porciani , Mauro Giavalisco

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…

Astrophysics · Physics 2009-11-07 J. Liske , G. M. Williger

We present a theoretical estimate for a new observable: the cross-correlation between the Lyman-alpha flux fluctuations in quasar (QSO) spectra and the convergence of the cosmic microwave background (CMB) as measured along the same…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Alberto Vallinotto , Sudeep Das , David N. Spergel , Matteo Viel

The Lyman-alpha forest is a portion of the observed light spectrum of distant galactic nuclei which allows us to probe remote regions of the Universe that are otherwise inaccessible. The observed Lyman-alpha forest of a quasar light…

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…

Astrophysics · Physics 2009-10-28 A. Fernandez-Soto , K. M. Lanzetta , X. Barcons , R. F. Carswell , J. K. Webb , A. Yahil

We examine the possible effects of UV background fluctuations on the pixel flux power spectrum and auto-correlation function of the LyA forest due to a finite number of sources in an attenuating medium. We consider scenarios in which QSO…

Astrophysics · Physics 2008-11-26 Avery Meiksin , Martin White