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Related papers: Exploring the Spectral Space of Low Redshift QSOs

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We apply two sparse reconstruction techniques, the least absolute shrinkage and selection operator (LASSO) and the sparse exponential mode analysis (SEMA), to two-dimensional (2D) spectroscopy. The algorithms are first tested on model data,…

Signal Processing · Electrical Eng. & Systems 2020-07-01 Zhengjun Wang , Shiwen Lei , Khadga Jung Karki , Andreas Jakobsson , Tönu Pullerits

Electron cryomicroscopy (cryo-EM) is a technique in structural biology used to reconstruct accurate volumetric maps of molecules. One step of the cryo-EM pipeline involves solving an inverse-problem. This inverse-problem, referred to as…

Quantitative Methods · Quantitative Biology 2024-11-26 Aaditya V. Rangan , Wai-Shing Tang , Pilar Cossio , Kexin Zhang , Nikolaus Grigorieff

Shuffled linear regression (SLR) seeks to estimate latent features through a linear transformation, complicated by unknown permutations in the measurement dimensions. This problem extends traditional least-squares (LS) and Least Absolute…

Statistics Theory · Mathematics 2025-04-17 Hang Liu , Anna Scaglione

We determine the number counts and z=0-5 luminosity function for a well-defined, homogeneous sample of quasars from the Sloan Digital Sky Survey (SDSS). We conservatively define the most uniform statistical sample possible, consisting of…

SKA-MID surveys will be the first in the radio domain to achieve clearly sub-arcsecond resolution at high sensitivity over large areas, opening new science applications for galaxy evolution. To investigate the potential of these surveys, we…

The recent developments of basis pursuit and compressed sensing seek to extract information from as few samples as possible. In such applications, since the number of samples is restricted, one should deploy the sampling points wisely. We…

Information Theory · Computer Science 2012-07-26 Rui Wang , Haizhang Zhang

Planetary transits detected by the CoRoT mission can be mimicked by a low-mass star in orbit around a giant star. Spectral classification helps to identify the giant stars and also early-type stars which are often excluded from further…

Solar and Stellar Astrophysics · Physics 2019-02-12 M. Ammler-von Eiff , D. Sebastian , E. W. Guenther , B. Stecklum , J. Cabrera

We explore the science prospects of a 14,000 deg$^2$ Kinematic Lensing (KL) survey with the Dark Energy Spectroscopic Instrument (DESI) and overlapping imaging surveys. KL infers the cosmic shear signal by jointly forward modeling the…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-31 Jiachuan Xu , Tim Eifler , Eason Wang , Elisabeth Krause , Spencer Everett , Eric Huff , Pranjal R. S. , Yu-Hsiu Huang

In this paper we present preliminary spectroscopic results from a small area faint K-excess (KX) survey, and compare KX selection against UVX selection. The aim of the KX method is to produce complete samples of QSOs flux-limited in the K…

Astrophysics · Physics 2011-03-10 Scott M. Croom , S. J. Warren , K. Glazebrook

Model uncertainties in the non-linear structure growth limit current probes of cosmological parameters. To shed more light on the physics of non-linear scales, we reconstructed the finely binned three-dimensional power-spectrum from lensing…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-18 Patrick Simon , Lucas Porth , Pierre Burger , Konrad Kuijken

The K20 survey is a near infrared-selected, deep (Ks < 20) redshift survey targeting galaxies in two independent regions of the sky, the CDFS and the q0055-2659 field. The total Ks-selected sample includes 545 objects. Optical spectra for…

We present high S/N UV spectra for eight quasars at z $\sim$ 3 obtained with VLT/FORS. The spectra enable us to analyze in detail the strong and weak emission features in the rest-frame range 1300-2000 A of each source (Ciii]$\lambda$1909,…

Astrophysics of Galaxies · Physics 2015-06-19 C. A. Negrete , D. Dultzin , P. Marziani , J. W. Sulentic

New instrumental capabilities and the wealth of astrophysical information extractable from the near-infrared wavelength region have led to a growing interest in the field of high resolution spectroscopy at 1-5 mu. We aim to provide a…

Single-shot magnetic resonance (MR) imaging acquires the entire k-space data in a single shot and it has various applications in whole-body imaging. However, the long acquisition time for the entire k-space in single-shot fast spin echo…

Image and Video Processing · Electrical Eng. & Systems 2024-09-13 Hemant Kumar Aggarwal , Sudhanya Chatterjee , Dattesh Shanbhag , Uday Patil , K. V. S. Hari

We present a catalog of quasars and corresponding redshifts in the Kilo-Degree Survey (KiDS) Data Release 4. We trained machine learning (ML) models, using optical ugri and near-infrared ZYJHK_s bands, on objects known from Sloan Digital…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 S. J. Nakoneczny , M. Bilicki , A. Pollo , M. Asgari , A. Dvornik , T. Erben , B. Giblin , C. Heymans , H. Hildebrandt , A. Kannawadi , K. Kuijken , N. R. Napolitano , E. Valentijn

[O III]$\lambda\lambda$4960,5008 doublet are often the strongest narrow emission lines in starburst galaxies and quasi-stellar objects (QSOs), and thus are a promising probe to possible variation of the fine-structure constant $\alpha$ over…

Astrophysics of Galaxies · Physics 2023-10-30 Ge Li , Luming Sun , Xiangjun Chen , Hongyan Zhou

Reconstructing the intrinsic Ly$\alpha$ line flux from high-$z$ QSOs can place constraints on the neutral hydrogen content of the intergalactic medium during reionisation. There are now $\gtrsim10$ different Ly$\alpha$ reconstruction…

The Sandage-Loeb (SL) test directly measures the expansion rate of the universe in the redshift range of $2\lesssim z\lesssim 5$ by detecting redshift drift in the spectra of Lyman-$\alpha$ forest of distant quasars. We discuss the impact…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-11 Jia-Jia Geng , Jing-Fei Zhang , Xin Zhang

A new class of high-contrast image analysis algorithms that empirically fit and subtract systematic noise has lead to recent discoveries of faint exoplanet /substellar companions and scattered light images of circumstellar disks. These…

Instrumentation and Methods for Astrophysics · Physics 2016-06-29 Laurent Pueyo

In this paper we describe the spherical harmonic transit telescope, a novel formalism for the analysis of transit radio telescopes. This all-sky approach bypasses the curved sky complications of traditional interferometry and so is…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-14 J. Richard Shaw , Kris Sigurdson , Ue-Li Pen , Albert Stebbins , Michael Sitwell