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The Lyman Alpha damping wing is seen in absorption against the spectra of high-redshift galaxies. Modeling of this wing is a way to measure the volume neutral hydrogen fraction of the Universe, as well as to measure the strength of HI…

Astrophysics of Galaxies · Physics 2025-05-14 Mason Huberty , Claudia Scarlata , Matthew J. Hayes , Simon Gazagnes

Fine-tuning large-scale pretrained models has led to tremendous progress in well-studied modalities such as vision and NLP. However, similar gains have not been observed in many other modalities due to a lack of relevant pretrained models.…

Machine Learning · Computer Science 2023-03-21 Junhong Shen , Liam Li , Lucio M. Dery , Corey Staten , Mikhail Khodak , Graham Neubig , Ameet Talwalkar

The distribution of the absorption line broadening observed in the Ly$\alpha$ forest carries information about the temperature and widths of the filaments in the intergalactic medium (IGM). In this work, we present and test a new method for…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-04 Antonella Garzilli , Tom Theuns , Joop Schaye

We present a new method for constructing three-dimensional mass maps from gravitational lensing shear data. We solve the lensing inversion problem using truncation of singular values (within the context of generalized least squares…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Jake VanderPlas , Andrew Connolly , Bhuvnesh Jain , Mike Jarvis

We present LyMAS2, an improved version of the "Lyman-{\alpha} Mass Association Scheme" aiming at predicting the large-scale 3d clustering statistics of the Lyman-{\alpha} forest (Ly-{\alpha}) from moderate resolution simulations of the dark…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-25 S. Peirani , S. Prunet , S. Colombi , C. Pichon , D. H. Weinberg , C. Laigle , G. Lavaux , Y. Dubois , J. Devriendt

Primary health care frequently relies on low-cost imaging devices, which are commonly used for screening purposes. To ensure accurate diagnosis, these systems depend on advanced reconstruction algorithms designed to approximate the…

Computer Vision and Pattern Recognition · Computer Science 2026-03-06 Thomas Pinetz , Veit Hucke , Hrvoje Bogunovic

In this work, we propose to leverage a deep-learning (DL) based reconstruction framework for high quality Swept-Source Optical Coherence Tomography (SS-OCT) images, by incorporating wavelength ({\lambda}) space interferometric fringes.…

Image and Video Processing · Electrical Eng. & Systems 2024-10-08 Maryam Viqar , Erdem Sahin , Violeta Madjarova , Elena Stoykova , Keehoon Hong

We present a novel maximum a posteriori estimator to jointly estimate band-powers and the covariance of the three-dimensional power spectrum (P3D) of Lyman-alpha forest flux fluctuations, called MAPLE. Our Wiener-filter based algorithm…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-27 Benjamin Horowitz , Roger de Belsunce , Zarija Lukic

We show that it is now possible to image optically thick $\lya$ clouds in fluorescent $\lya$ emission with a relatively long ($\sim 20 $hr) integration on a large ($\sim 10 $m) telescope. For a broad range of column densities ($N\gsim…

Astrophysics · Physics 2009-10-28 Andrew Gould , David H. Weinberg

In this Letter we explore a version of the test of cosmological geometry proposed by Alcock and Paczynski (1979), using observations of the Lyman-alpha forest in the spectra of close quasar pairs. By comparing the correlations in absorption…

Astrophysics · Physics 2009-10-30 Lam Hui , Albert Stebbins , Scott Burles

The apparent angular positions of quasars are deflected on the sky by the gravitational field sourced by foreground matter. This weak lensing effect is measurable through the distortions it introduces in the lensed quasar spectra.…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-03 Patrick Shaw , Rupert A. C. Croft , R. Benton Metcalf

Hydrodynamical cosmological simulations are a powerful tool for accurately predicting the properties of the intergalactic medium (IGM) and for producing mock skies that can be compared against observational data. However, the need to…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-08 Cooper Jacobus , Peter Harrington , Zarija Lukić

We introduce COBRA (Cosmology with Optimally factorized Bases of Radial Approximants), a novel framework for rapid computation of large-scale structure observables. COBRA separates scale dependence from cosmological parameters in the linear…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-15 Thomas Bakx , Nora Elisa Chisari , Zvonimir Vlah

Our understanding of the Lyman-$\alpha$ forest has received a great boost with the advent of the Keck Telescope and large 3D hydrodynamical simulations. We present new simulations using the SPH technique with a P^3MG (Particle-Particle…

Astrophysics · Physics 2007-05-23 J. W. Wadsley , J. Richard Bond

Observations of the Lyman-$\alpha$ forest in distant quasar spectra with upcoming surveys are expected to provide significantly larger and higher-quality datasets. To interpret these datasets, it is imperative to develop efficient…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-13 Bhaskar Arya , Tirthankar Roy Choudhury , Aseem Paranjape , Prakash Gaikwad

The low-redshift evolution of the intergalactic medium is investigated using hydrodynamic cosmological simulations. The assumed cosmological model is a critical density cold dark matter universe. The imposed uniform background of ionizing…

Astrophysics · Physics 2009-10-30 T. Theuns , A. Leonard , G. Efstathiou

We address the problem of inferring the three-dimensional matter distribution from a sparse set of one-dimensional quasar absorption spectra of the Lyman-$\alpha$ forest. Using a Bayesian forward modelling approach, we focus on extending…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-14 Natalia Porqueres , Oliver Hahn , Jens Jasche , Guilhem Lavaux

We aim to construct a machine-learning approach that allows for a pixel-by-pixel reconstruction of the intergalactic medium (IGM) density field for various warm dark matter (WDM) models using the Lyman-alpha forest. With this regression…

Lyman-alpha forest data probing the post-reionization Universe shows surprisingly large opacity fluctuations over rather large ($\ge$50 comoving Mpc/h) spatial scales. We model these fluctuations using a hybrid approach utilizing the large…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-21 Jonathan Chardin , Ewald Puchwein , Martin G. Haehnelt

We search for OVI absorption in a Keck HIRES spectrum of the z=3.62 quasar Q1422+231. Comparison of CIV measurements to cosmological simulations shows that \lya forest absorbers with N_HI > 10^{14.5} have [C/H]~=-2.5, for the UV background…

Astrophysics · Physics 2009-10-30 Romeel Davé , Uffe Hellsten , Lars Hernquist , Neal Katz , David Weinberg
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