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We have designed, developed, and applied a convolutional neural network (CNN) architecture using multi-task learning to search for and characterize strong HI Lya absorption in quasar spectra. Without any explicit modeling of the quasar…

Astrophysics of Galaxies · Physics 2018-02-14 David Parks , J. Xavier Prochaska , Shawfeng Dong , Zheng Cai

We present the Damped Ly$\alpha$ Toolkit for automated detection and characterization of Damped Ly$\alpha$ absorbers (DLA) in quasar spectra. Our method uses quasar spectral templates with and without absorption from intervening DLAs to…

We present an automatic method based on machine-learning convolutional neural network (CNN) architecture to detect Lyman alpha emitters (LAE) hidden in the Data Release 1 spectroscopic dataset of the Dark Energy Spectroscopic Instrument…

In the Coded Aperture Snapshot Spectral Imaging (CASSI) system, deep unfolding networks (DUNs) have demonstrated excellent performance in recovering 3D hyperspectral images (HSIs) from 2D measurements. However, some noticeable gaps exist…

Image and Video Processing · Electrical Eng. & Systems 2024-01-17 Yubo Dong , Dahua Gao , Yuyan Li , Guangming Shi , Danhua Liu

We develop a machine learning based algorithm using a convolutional neural network (CNN) to identify low HI column density Ly$\alpha$ absorption systems ($\log{N_{\mathrm{HI}}}/{\rm cm}^{-2}<17$) in the Ly$\alpha$ forest, and predict their…

Astrophysics of Galaxies · Physics 2022-09-28 Ting-Yun Cheng , Ryan Cooke , Gwen Rudie

We present the results from the optical component of a survey for damped Lyman-alpha systems (DLAs) towards radio-loud quasars. Our quasar sample is drawn from the Texas radio survey with the following primary selection criteria: z_em >…

Astrophysics · Physics 2009-11-13 Sara L. Ellison , Brian A. York , Max Pettini , Nissim Kanekar

Deep learning (DL) has been shown to outperform traditional, human-defined summary statistics of the Ly{\alpha} forest in constraining key astrophysical and cosmological parameters owing to its ability to tap into the realm of non-Gaussian…

Instrumentation and Methods for Astrophysics · Physics 2025-10-24 Parth Nayak , Michael Walther , Daniel Gruen

We demonstrate the potential of Deep Learning methods for measurements of cosmological parameters from density fields, focusing on the extraction of non-Gaussian information. We consider weak lensing mass maps as our dataset. We aim for our…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Jorit Schmelzle , Aurelien Lucchi , Tomasz Kacprzak , Adam Amara , Raphael Sgier , Alexandre Réfrégier , Thomas Hofmann

We searched for evidence of reddening of background SDSS QSO spectra due to dust in intervening DLA systems. We utilise the Data Releases 5 and 7 to arrive at sample sizes of 475 (DR5) and 676 (DR7) absorbers, based on two different…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. Frank , C. Péroux

We present a deep learning framework to enhance the identification of Ly$\alpha$ emitters (LAEs) in the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), an untargeted spectroscopic survey of LAEs at $1.9 < z < 3.5$ without imaging…

We use the average E(B-V) and ZnII column densities of a sample of z~1 CaII (3935, 3970) absorption line systems selected from the Sloan Digital Sky Survey (SDSS DR4) to show that on average, with conservative assumptions regarding…

Astrophysics · Physics 2009-11-11 Vivienne Wild , Paul Hewett , Max Pettini

Machine Learning (ML) algorithms are becoming popular in cosmology for extracting valuable information from cosmological data. In this paper, we evaluate the performance of a Convolutional Neural Network (CNN) trained on matter density…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-03 Amirmohammad Chegeni , Farbod Hassani , Alireza Vafaei Sadr , Nima Khosravi , Martin Kunz

We present a new catalogue of Damped Lyman-$\alpha$ absorbers from SDSS DR16Q, as well as new estimates of their statistical properties. Our estimates are computed with the Gaussian process models presented in Garnett et al. (2017); Ho et…

Astrophysics of Galaxies · Physics 2021-08-24 Ming-Feng Ho , Simeon Bird , Roman Garnett

We present new estimates for the statistical properties of damped Lyman-$\alpha$ absorbers (DLAs). We compute the column density distribution function at $z>2$, the line density, $\mathrm{d}N/\mathrm{d}X$, and the neutral hydrogen density,…

Astrophysics of Galaxies · Physics 2017-01-25 Simeon Bird , Roman Garnett , Shirley Ho

We present the results of our automatic search for proximate damped Ly$\alpha$ absorption (PDLA) systems in the quasar spectra from the Sloan Digital Sky Survey Data Release 12. We constrain our search to those PDLAs lying within 1500 km…

Semantic labeling (or pixel-level land-cover classification) in ultra-high resolution imagery (< 10cm) requires statistical models able to learn high level concepts from spatial data, with large appearance variations. Convolutional Neural…

Computer Vision and Pattern Recognition · Computer Science 2017-03-08 Michele Volpi , Devis Tuia

We have identified a metal-strong (logN(Zn+) > 13.15 or logN(Si+) > 15.95) DLA (MSDLA) population from an automated quasar (QSO) absorber search in the Sloan Digital Sky Survey Data Release 3 (SDSS-DR3) quasar sample, and find that MSDLAs…

DESI is a groundbreaking international project to observe more than 40 million quasars and galaxies over a 5-year period to create a 3D map of the sky. This map will enable us to probe multiple aspects of cosmology, from dark energy to…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Julien Taran

This paper presents a comparison of several Convolutional Neural Network (CNN) models for extracting target signals in highly noisy measurement conditions. Four CNN architectures were investigated. The first comprises six consecutive…

Signal Processing · Electrical Eng. & Systems 2024-10-11 Andrea Faúndez Quezada , Salvatore La Cavera , Sidahmed A Abayzeed

We study the cross correlation of damped Ly$\alpha$ systems (DLAs) and their background quasars, using the most updated DLA catalog and the Planck 2018 CMB lensing convergence field. Our measurement suggests that the DLA bias $b_{\rm DLA}$…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-06 Xiaojing Lin , Zheng Cai , Yin Li , Alex Krolewski , Simone Ferraro
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