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相关论文: Estimating Galaxy Redshift in Radio-Selected Datas…

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AGNs are very powerful galaxies characterized by extremely bright emissions coming out from their central massive black holes. Knowing the redshifts of AGNs provides us with an opportunity to determine their distance to investigate…

Machine learning techniques, specifically the k-nearest neighbour algorithm applied to optical band colours, have had some success in predicting photometric redshifts of quasi-stellar objects (QSOs): Although the mean of differences between…

天体物理仪器与方法 · 物理学 2020-01-29 S. J. Curran

We present a robust method to estimate the redshift of galaxies using Pan-STARRS1 photometric data. Our method is an adaptation of the one proposed by Beck et al. (2016) for the SDSS Data Release 12. It uses a training set of 2313724…

星系天体物理 · 物理学 2020-10-14 Paula Tarrío , Stefano Zarattini

Next-generation radio surveys are expected to detect tens of millions of active galactic nuclei (AGN) with a median redshift of z > 1. Beyond targeted surveys, the vast majority of these objects will not have spectroscopic redshifts, whilst…

星系天体物理 · 物理学 2020-11-03 Ross J. Turner , Guillaume Drouart , Nick Seymour , Stanislav S. Shabala

We developed a Deep Convolutional Neural Network (CNN), used as a classifier, to estimate photometric redshifts and associated probability distribution functions (PDF) for galaxies in the Main Galaxy Sample of the Sloan Digital Sky Survey…

天体物理仪器与方法 · 物理学 2018-12-26 Johanna Pasquet , Emmanuel Bertin , Marie Treyer , Stéphane Arnouts , Dominique Fouchez

We present an empirical method for estimating the underlying redshift distribution N(z) of galaxy photometric samples from photometric observables. The method does not rely on photometric redshift (photo-z) estimates for individual…

天体物理学 · 物理学 2008-11-26 Marcos Lima , Carlos E. Cunha , Hiroaki Oyaizu , Joshua Frieman , Huan Lin , Erin S. Sheldon

We showcase machine learning (ML) inspired target selection algorithms to determine which of all potential targets should be selected first for spectroscopic follow up. Efficient target selection can improve the ML redshift uncertainties as…

天体物理仪器与方法 · 物理学 2016-06-16 Ben Hoyle , Kerstin Paech , Markus Michael Rau , Stella Seitz , Jochen Weller

In the context of radio galaxy classification, most state-of-the-art neural network algorithms have been focused on single survey data. The question of whether these trained algorithms have cross-survey identification ability or can be…

天体物理仪器与方法 · 物理学 2019-07-31 Hongming Tang , Anna M. M. Scaife , J. P. Leahy

We explore how information in images of nearby galaxies can be used to estimate their distance. We train a convolutional Neural Network (NN) to do this, using galaxy images from the Illustris simulation. We show that if the NN is trained on…

宇宙学与河外天体物理 · 物理学 2022-04-21 Kevin M. Quigley , Samuel Hori , Rupert A. C. Croft

Context: In astronomy, new approaches to process and analyze the exponentially increasing amount of data are inevitable. While classical approaches (e.g. template fitting) are fine for objects of well-known classes, alternative techniques…

星系天体物理 · 物理学 2016-08-08 S. D. Kügler , K. Polsterer , M. Hoecker

In this paper, we address the problem of spectroscopic redshift estimation in Astronomy. Due to the expansion of the Universe, galaxies recede from each other on average. This movement causes the emitted electromagnetic waves to shift from…

We introduce a new Bayesian HI spectral line fitting technique capable of obtaining spectroscopic redshifts for millions of galaxies in radio surveys with the Square Kilometere Array (SKA). This technique is especially well-suited to the…

宇宙学与河外天体物理 · 物理学 2017-04-28 Ian Harrison , Michelle Lochner , Michael L. Brown

Galaxy groups are essential for studying the distribution of matter on a large scale in redshift surveys and for deciphering the link between galaxy traits and their associated halos. In this work, we propose a widely applicable method for…

宇宙学与河外天体物理 · 物理学 2025-04-03 Juntao Ma , Jie Wang , Tianxiang Mao , Hongxiang Chen , Yuxi Meng , Xiaohu Yang , Qingyang Li

The redshifts of galaxies are a key attribute that is needed for nearly all extragalactic studies. Since spectroscopic redshifts require additional telescope and human resources, millions of galaxies are known without spectroscopic…

星系天体物理 · 物理学 2021-07-21 S. Schuldt , S. H. Suyu , R. Cañameras , S. Taubenberger , T. Meinhardt , L. Leal-Taixé , B. C. Hsieh

Gamma-ray bursts (GRBs) detected at high redshift can be used to trace the cosmic expansion history. However, the calibration of their luminosity distances is not an easy task in comparison to Type Ia Supernovae (SNeIa). To calibrate these…

宇宙学与河外天体物理 · 物理学 2022-04-20 Celia Escamilla-Rivera , Maryi Carvajal , Cristian Zamora , Martin Hendry

Data-driven approaches play a crucial role in space computing, and our paper focuses on analyzing data to learn more about celestial objects. Photometric redshift, a measure of the shift of light towards the red part of the spectrum, helps…

天体物理仪器与方法 · 物理学 2024-11-22 Krishna Chunduri , Mithun Mahesh

Machine learning techniques offer a plethora of opportunities in tackling big data within the astronomical community. We present the set of Generalized Linear Models as a fast alternative for determining photometric redshifts of galaxies, a…

天体物理仪器与方法 · 物理学 2016-06-29 J. Elliott , R. S. de Souza , A. Krone-Martins , E. Cameron , E. E. O. Ishida , J. Hilbe

The scientific value of the next generation of large continuum surveys would be greatly increased if the redshifts of the newly detected sources could be rapidly and reliably estimated. Given the observational expense of obtaining…

宇宙学与河外天体物理 · 物理学 2021-03-03 S. J. Curran , J. P. Moss , Y. C. Perrott

The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the $z'$ and $R_c$ bands for ~90 square degrees of sky, and supplemental $V$ and $B$ data have been obtained for 33.6 deg$^{2}$. We compile a…

天体物理学 · 物理学 2009-11-10 B. C. Hsieh , H. K. C. Yee , H. Lin , M. D. Gladders

The forthcoming Wide Area Vista Extragalactic Survey (WAVES) on the 4-metre Multi-Object Spectroscopic Telescope (4MOST) has a key science goal of probing the halo mass function to lower limits than possible with previous surveys. For that…

宇宙学与河外天体物理 · 物理学 2025-03-03 Gursharanjit Kaur , Maciej Bilicki , Wojciech Hellwing , the WAVES team