English
Related papers

Related papers: Spectral Analysis of the Lyman-Alpha Forest Using …

200 papers

Absorption between the rest-frame wavelengths of 973 and 1026 Angstroms in quasar spectra arises from two sources (apart from occasional metals): one is due to Lyman-alpha (Lya) absorption by materials at a low redshift, and the other from…

Astrophysics · Physics 2009-11-07 Mark Dijkstra , Adam Lidz , Lam Hui

We have measured the distribution function of the flux decrement caused by Lyman alpha forest absorption in a new sample of high resolution QSO spectra. The observations are compared to the results from two simulations of the Lya forest: an…

We present precision measurements of the bias parameters of the one-loop power spectrum model of the Lyman-alpha (Lya) forest, derived within the effective field theory of large-scale structure (EFT). We fit our model to the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-26 Roger de Belsunce , Shi-Fan Chen , Mikhail M. Ivanov , Corentin Ravoux , Solene Chabanier , Jean Sexton , Zarija Lukic

We present the Lyman-$\alpha$ flux power spectrum measurements of the XQ-100 sample of quasar spectra obtained in the context of the European Southern Observatory Large Programme "Quasars and their absorption lines: a legacy survey of the…

We present a search for spatial and redshift correlations in a 2 A resolution spectroscopic survey of the Lyman alpha forest at 2.15 < z < 3.37 toward ten QSOs concentrated within a 1-degree diameter field. We find a signal at 2.7 sigma…

Astrophysics · Physics 2009-10-31 G. M. Williger , A. Smette , C. Hazard , J. A. Baldwin , R. G. McMahon

Recent studies have focused on the low-$z$ Ly$\alpha$ forest as a potential constraint on galactic feedback, as different AGN and stellar feedback models in hydrodynamic simulations produce varying intergalactic medium (IGM) statistics.…

Astrophysics of Galaxies · Physics 2025-08-26 Megan T. Tillman , Joseph N. Burchett , Blakesley Burkhart , Vikram Khaire , Sanchayeeta Borthakur

In this article, we investigate the application of wavelet packet transform as a novel spectrum sensing approach. The main attraction for wavelet packets is the tradeoffs they offer in terms of satisfying various performance metrics such as…

Information Theory · Computer Science 2013-04-16 Dyonisius Dony Ariananda , Madan Kumar Lakshmanan , Homayoun Nikookar

We have compiled, from the literature, a sample of Ly ${\alpha}$ forest lines in the spectra of 69 QSOs, all observed with a resolution between 60 to 100 km s$^{-1}$. The sample is studied for proximity effect. We have tried to account for…

Astrophysics · Physics 2015-06-24 R. Srianand , Pushpa Khare

For the purpose of studying the properties of heavy-elements associated with the Lyman-$\alpha$\ forest, we observed the gravitational lens Q1422+2309. We used the HIRES instrument on the W.M. Keck telescope to obtain a high-resolution,…

Astrophysics · Physics 2016-01-27 D. S. Womble , W. L. W. Sargent , R. S. Lyons

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

The analysis of the Lyman-alpha forest of absorption lines in quasar spectra has emerged as a potentially powerful technique to constrain the linear matter power spectrum. In most previous work, the amplitude of the ionizing background was…

Astrophysics · Physics 2009-11-11 Adam Lidz , Katrin Heitmann , Lam Hui , Salman Habib , Michael Rauch , Wallace L. W. Sargent

Numerical hydrodynamical simulations are used to predict the expected absorption properties of the Lyman-Alpha forest for a variety of Cold Dark Matter dominated cosmological scenarios: CHDM, OCDM, LCDM, SCDM, and tCDM. Synthetic spectra…

Astrophysics · Physics 2009-11-06 A. Meiksin , G. Bryan , M. Machacek

Current results from the Lyman alpha forest assume that the primordial power spectrum of density perturbations follows a simple power law form, with running. We present the first analysis of Lyman alpha data to study the effect of relaxing…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-16 Simeon Bird , Hiranya V. Peiris , Matteo Viel , Licia Verde

We compare the observed probability distribution function of the transmission in the \HI\ Lyman-alpha forest, measured from the UVES 'Large Programme' sample at redshifts z=[2,2.5,3], to results from the GIMIC cosmological simulations. Our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Emmanuel Rollinde , Tom Theuns , Joop Schaye , Isabelle Pâris , Patrick Petitjean

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…

Astrophysics · Physics 2009-11-13 Jiren Liu , Hongguang Bi , Li-Zhi Fang

Using a set of 28 high resolution, high signal to noise ratio (S/N) QSO Ly-alpha absorption spectra, we investigate the non-Gaussian features of the transmitted flux fluctuations, and their effect upon the power spectrum of this field. We…

Astrophysics · Physics 2009-11-07 Priya Jamkhedkar , Long-Long Feng , Wei Zheng , David Kirkman , David Tytler , Li-Zhi Fang

We measure the linear power spectrum of mass density fluctuations at redshift z=2.5 from the \lya forest absorption in a sample of 19 QSO spectra, using the method introduced by Croft et al. (1998). The P(k) measurement covers the range…

Astrophysics · Physics 2009-10-31 Rupert A. C. Croft , David H. Weinberg , Max Pettini , Lars Hernquist , Neal Katz

We use, for the first time, the Detrend Fluctuation Analysis (DFA) to study the correlation properties of the transmitted flux fluctuations, in the Lyman-$\alpha$ (Ly$\alpha$) Forest along the lines of sight (LOS) to QSOs, at different…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-23 R. N. Guimarães , P. Petitjean , E. Rollinde , S. G. Djorgovski , M. S. da Silva , M. A Moret

We investigate the effect of non-Gaussianity on the reconstruction of the initial mass field from the Ly$\alpha$ forest. We show that the transmitted flux of QSO absorption spectra are highly non-Gaussian in terms of the statistics, the…

Astrophysics · Physics 2009-10-31 Long-Long Feng , Li-Zhi Fang