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Related papers: The Time-Domain Spectroscopic Survey: Target Selec…

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We obtained medium-resolution spectra of 336 quasar candidates in the COSMOS HST/Treasury field using the MMT 6.5-meter telescope and the Hectospec multi-object spectrograph. Candidates were drawn from the Sloan Digital Sky Survey (SDSS)…

Astrophysics · Physics 2009-11-11 M. K. M. Prescott , C. D. Impey , R. J. Cool , N. Z. Scoville

The Legacy Survey of Space and Time (LSST) at the Vera C. Rubin Observatory is poised to observe thousands of quasars using the Deep Drilling Fields (DDF) across six broadband filters over a decade. Understanding quasar accretion disc (AD)…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-20 F. Pozo Nuñez , B. Czerny , S. Panda , A. Kovacevic , W. Brandt , K. Horne

Large astronomical databases obtained from sky surveys such as the SuperCOSMOS Sky Surveys (SSS) invariably suffer from a small number of spurious records coming from artefactual effects of the telescope, satellites and junk objects in…

Artificial Intelligence · Computer Science 2014-08-08 Amos J. Storkey , Nigel C. Hambly , Christopher K. I. Williams , Robert G. Mann

Astronomical surveys of celestial sources produce streams of noisy time series measuring flux versus time ("light curves"). Unlike in many other physical domains, however, large (and source-specific) temporal gaps in data arise naturally…

Instrumentation and Methods for Astrophysics · Physics 2017-11-30 Brett Naul , Joshua S. Bloom , Fernando Pérez , Stéfan van der Walt

The Legacy Survey of Space and Time (LSST), being conducted by the Vera C. Rubin Observatory, is a wide-field multi-band survey that will revolutionize our understanding of extragalactic sources through its unprecedented combination of area…

AIMS: We present a sample of candidate quasars selected using the KX-technique. The data cover 0.68 deg^2 of the X-ray Multi-Mirror (XMM) Large-Scale Structure (LSS) survey area where overlapping multi-wavelength imaging data permits an…

We apply a convolutional neural network (CNN) to classify and detect quasars in the Sloan Digital Sky Survey Stripe 82 and also to predict the photometric redshifts of quasars. The network takes the variability of objects into account by…

Instrumentation and Methods for Astrophysics · Physics 2018-04-11 Johanna Pasquet-Itam , Jérôme Pasquet

Achieving high accuracy and precision in stellar parameter and chemical composition determinations is challenging in massive star spectroscopy. On one hand, the target selection for an unbiased sample build-up is complicated by several…

Solar and Stellar Astrophysics · Physics 2017-11-15 Maria-Fernanda Nieva , Norbert Przybilla

We present a catalog of broad H$\beta$ variability properties for all spectra of quasars with $z<0.8$ and at least two observations included in the Sloan Digital Sky Survey (SDSS) Data Release 16 quasar catalog. For each spectrum, we…

High Energy Astrophysical Phenomena · Physics 2026-01-30 Collin M. Dabbieri , Jessie C. Runnoe , Michael Eracleous , Mary E. Kaldor , Mary Ogborn , Niana N. Mohammed

In the recent papers [1-4] including above paper time modulated frequency diverse arrays (FDAs) have been presented to obtain time invariant spatial patterns. The presented FDAs in [1-3] have the feature of time-invariant spatial focusing…

Signal Processing · Electrical Eng. & Systems 2019-12-03 Mahdi Fartookzadeh

The uncertain origin of the recently-discovered `changing-looking' quasar phenomenon -- in which a luminous quasar dims significantly to a quiescent state in repeat spectroscopy over ~10 year timescales -- may present unexpected challenges…

The primary goals of the STRong lensing Insights into the Dark Energy Survey (STRIDES) collaboration are to measure the dark energy equation of state parameter and the free streaming length of dark matter. To this aim, STRIDES is…

The Herschel SPIRE Fourier transform spectrometer (FTS) performs spectral imaging in the 447-1546 GHz band. It can observe in three spatial sampling modes: sparse mode, with a single pointing on sky, or intermediate or full modes with 1 and…

The Baryon Acoustic Oscillation (BAO) feature in the power spectrum of galaxies can be used as a standard ruler to probe the accelerated expansion of the Universe. In this paper, we study several galaxy selection schemes aiming at building…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-22 S. Escoffier , J. Comparat , A. Ealet , J. -P. Kneib , J. Zoubian , F. Lamareille

An overview is given of the Permanent All Sky Survey (PASS) project. The primary goal of PASS is the detection of all transiting giant planets in the entire sky, complete for stellar systems of magnitudes ~ 5.5-10.5. Since the sample stars…

Diffusion models have gained attention for their success in modeling complex distributions, achieving impressive perceptual quality in SR tasks. However, existing diffusion-based SR methods often suffer from high computational costs,…

Computer Vision and Pattern Recognition · Computer Science 2025-05-22 Rui Qin , Qijie Wang , Ming Sun , Haowei Zhu , Chao Zhou , Bin Wang

Binary pulsars are an important target for radio surveys because they present a natural laboratory for a wide range of astrophysics for example testing general relativity, including detection of gravitational waves. The orbital motion of a…

Instrumentation and Methods for Astrophysics · Physics 2022-02-17 Karel Adámek , Jan Novotný , Sofia Dimoudi , Wesley Armour

We present cosmological constraints from 8 strongly lensed quasars (hereafter, the TDCOSMO-2025 sample). Building on previous work, our analysis incorporated new deflector stellar velocity dispersions measured from spectra obtained with the…

Quasar emission lines are often shifted from the systemic velocity due to various dynamical and radiative processes in the line-emitting region. The level of these velocity shifts depends both on the line species and on quasar properties.…

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