English
Related papers

Related papers: Photometric redshifts and quasar probabilities fro…

200 papers

The Dark Energy Spectroscopic Instrument (DESI) survey will provide optical spectra for $\sim 3$ million quasars. Accurate redshifts for these quasars will facilitate a broad range of science applications. Here we provide improved systemic…

Astrophysics of Galaxies · Physics 2023-08-31 Qiaoya Wu , Yue Shen

We use the photometric redshift method of Chakrabarti & McKee (2008) to infer photometric redshifts of submillimeter galaxies with far-IR (FIR) $\it{Herschel}$ data obtained as part of the PACS Evolutionary Probe (PEP) program. For the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Sukanya Chakrabarti , Benjamin Magnelli , Christopher F. McKee , Dieter Lutz , Stefano Berta , Paola Popesso , Francesca Pozzi

In this study, we propose a three-stage training approach of neural networks for both photometric redshift estimation of galaxies and detection of out-of-distribution (OOD) objects. Our approach comprises supervised and unsupervised…

Instrumentation and Methods for Astrophysics · Physics 2022-02-04 Joongoo Lee , Min-Su Shin

The next generation of cosmology experiments will be required to use photometric redshifts rather than spectroscopic redshifts. Obtaining accurate and well-characterized photometric redshift distributions is therefore critical for Euclid,…

Instrumentation and Methods for Astrophysics · Physics 2025-06-03 Ibrahim A. Almosallam , Matt J. Jarvis , Stephen J. Roberts

We calculate the observable properties of the most massive high-redshift galaxies in the hierarchical formation scenario where stellar spheroid and supermassive black hole growth are fueled by gas-rich mergers. Combining high-resolution…

Astrophysics · Physics 2010-11-05 Brant Robertson , Yuexing Li , Thomas J. Cox , Lars Hernquist , Philip F. Hopkins

Photometric redshifts have proven a powerful tool in identifying galaxies over a large range of lookback times. We have been generalising this technique to incorporate the selection of candidate high redshift QSOs. We have applied this to a…

Astrophysics · Physics 2009-11-07 E R Stanway , A Bunker , R G McMahon

A new method is developed for estimating photometric redshifts, using realistic template SEDs, extending over four decades in wavelength (i.e from 0.05 $\mu m$ to 1 mm). The SEDs are constructed for four different spectral types of galaxies…

Astrophysics · Physics 2007-05-23 B. Mobasher , P. Mazzei

We present a new approach to the problem of estimating the redshift of galaxies from photometric data. The approach uses a genetic algorithm combined with non-linear regression to model the 2SLAQ LRG data set with SDSS DR7 photometry. The…

Instrumentation and Methods for Astrophysics · Physics 2015-04-14 Robert Hogan , Malcolm Fairbairn , Navin Seeburn

Although starburst galaxies have relatively flat spectral energy distributions, their strong optical emission lines and near-UV continua make it very feasible to estimate their redshifts photometrically. In this work, I describe a…

Astrophysics · Physics 2007-05-23 Charles T. Liu

We present and compare in this paper new photometric redshift catalogs of the galaxies in three public fields: the NTT Deep Field, the HDF-N and the HDF-S. Photometric redshifts have been obtained for thewhole sample, by adopting a $\chi^2$…

Astrophysics · Physics 2009-10-31 A. Fontana , S. D'Odorico , F. Poli , E. Giallongo , S. Arnouts , S. Cristiani , A. Moorwood , P. Saracco

Multiple color selection techniques have been successful in identifying quasars from wide-field broad-band imaging survey data. Among the quasars that have been discovered so far, however, there is a redshift gap at $5 \lesssim {\rm z}…

Astrophysics of Galaxies · Physics 2017-01-18 Yiseul Jeon , Myungshin Im , Soojong Pak , Minhee Hyun , Sanghyuk Kim , Yongjung Kim , Hye-In Lee , Woojin Park

Our group has developed a technique that makes use of the observed non-linear relation between the ultraviolet and the X-ray luminosity in quasars to provide an independent measurement of their distances, thus turning quasars into…

Cosmology and Nongalactic Astrophysics · Physics 2020-03-05 Elisabeta Lusso

We present a deep BVrIK multicolor catalog of galaxies in the field of the high redshift (z=4.7) quasar BR 1202-0725. Reliable colors have been measured for galaxies selected down to R=25. The choice of the optical filters has been…

Astrophysics · Physics 2009-10-30 E. Giallongo , S. D'Odorico , A. Fontana , S. Cristiani , E. Egami , E. Hu , R. G. McMahon

We present Mantis Shrimp, a multi-survey deep learning model for photometric redshift estimation that fuses ultra-violet (GALEX), optical (PanSTARRS), and infrared (UnWISE) imagery. Machine learning is now an established approach for…

Instrumentation and Methods for Astrophysics · Physics 2025-08-01 Andrew Engel , Nell Byler , Adam Tsou , Gautham Narayan , Emmanuel Bonilla , Ian Smith

The aim of this paper is to investigate ways to optimize the accuracy of photometric redshifts for a SNAP like mission. We focus on how the accuracy of the photometric redshifts depends on the magnitude limit and signal-to-noise ratio,…

As a consequence of galaxy clustering, close galaxies observed on the plane of the sky should be spatially correlated with a probability that is inversely proportional to their angular separation. In principle, this information can be used…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 F. Tosone , M. S. Cagliari , L. Guzzo , B. R. Granett , A. Crespi

Photometric wide-field surveys are imaging the sky in unprecedented detail. These surveys face a significant challenge in efficiently estimating galactic photometric redshifts while accurately quantifying associated uncertainties. In this…

We present spectroscopic measurements for 226 sources from the Gemini Near Infrared Spectrograph - Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a flux-limited sample ($m_{i}$…

We present initial results from the first systematic survey of luminous $z\sim 5.5$ quasars. Quasars at $z \sim$ 5.5, the post-reionization epoch, are crucial tools to explore the evolution of intergalactic medium, quasar evolution and the…

An accurate calibration of the source redshift distribution $p(z)$ is a key aspect in the analysis of cosmic shear data. This, one way or another, requires the use of spectroscopic or high-quality photometric samples. However, the…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Carlos García-García , David Alonso , Pedro G. Ferreira , Boryana Hadzhiyska , Andrina Nicola , Carles Sánchez , Anže Slosar
‹ Prev 1 3 4 5 6 7 10 Next ›