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Related papers: Galaxy Spectra neural Network (GaSNet). II. Using …

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Estimating redshifts from broadband photometry is often limited by how accurately we can map the colors of galaxies to an underlying spectral template. Current techniques utilize spectrophotometric samples of galaxies or spectra derived…

Instrumentation and Methods for Astrophysics · Physics 2025-03-11 John Franklin Crenshaw , Andrew J. Connolly

We calculate photometric redshifts from the Sloan Digital Sky Survey Data Release 2 Galaxy Sample using artificial neural networks (ANNs). Different input patterns based on various parameters (e.g. magnitude, color index, flux information)…

Astrophysics · Physics 2007-05-23 Lili Li , Yanxia Zhang , Yongheng Zhao , Dawei Yang

Automated techniques have been developed to automate the process of classification of objects or their analysis. The large datasets provided by upcoming spectroscopic surveys with dedicated telescopes urges scientists to use these automated…

Astrophysics · Physics 2009-06-23 Mahdi Bazarghan , Ranjan Gupta

We apply a new deep learning technique to detect, classify, and deblend sources in multi-band astronomical images. We train and evaluate the performance of an artificial neural network built on the Mask R-CNN image processing framework, a…

Instrumentation and Methods for Astrophysics · Physics 2019-11-22 Colin J. Burke , Patrick D. Aleo , Yu-Ching Chen , Xin Liu , John R. Peterson , Glenn H. Sembroski , Joshua Yao-Yu Lin

We present a new method for inferring photometric redshifts in deep galaxy and quasar surveys, based on a data driven model of latent spectral energy distributions (SEDs) and a physical model of photometric fluxes as a function of redshift.…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Boris Leistedt , David W. Hogg

In modern analysis pipelines, Einstein-Boltzmann Solvers (EBSs) are an invaluable tool for obtaining CMB and matter power spectra. To accelerate the computation of these observables, the CosmicNet strategy is to replace the bottleneck of an…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 Sven Günther , Julien Lesgourgues , Georgios Samaras , Nils Schöneberg , Florian Stadtmann , Christian Fidler , Jesús Torrado

The Dark Energy Spectroscopic Instrument (DESI) Survey has obtained a set of spectroscopic measurements of galaxies to validate the final survey design and target selections. To assist in these tasks, we visually inspect (VI) DESI spectra…

We construct a supervised classifier based on Gaussian Mixture Models to probabilistically classify objects in Gaia data release 2 (GDR2) using only photometric and astrometric data in that release. The model is trained empirically to…

Astrophysics of Galaxies · Physics 2019-11-06 Coryn A. L. Bailer-Jones , Morgan Fouesneau , Rene Andrae

In this work, we enhance the FNet, a 1-dimensional convolutional neural network (CNN) with a residual neural network (ResNet) architecture, to perform spectral classification of quasars, galaxies, stars, and broad absorption line…

Astrophysics of Galaxies · Physics 2024-10-25 R. Moradi , F. Rastegarnia , Y. Wang , M. T. Mirtorabi

We present a new approach to capturing the broad diversity of emission line and continuum properties in quasar spectra. We identify populations of spectrally similar quasars through pixel-level clustering on 12,968 high signal-to-noise…

Astrophysics of Galaxies · Physics 2022-02-16 Allyson Brodzeller , Kyle Dawson

The DEEP2/DEIMOS redshift survey, which will begin observing in the Spring of 2002, will gather high quality spectra on ~60000 galaxies in order to study the evolution of the properties and large scale clustering of galaxies at z~1. The…

Astrophysics · Physics 2007-05-23 Christian Marinoni , Marc Davis , Alison L. Coil , Douglas Finkbeiner

This paper presents a comprehensive study of quasar photometric classification and redshift estimation using machine learning techniques. We cross-matched photometric data from the Dark Energy Survey Data Release 2 (DES DR2) with…

Instrumentation and Methods for Astrophysics · Physics 2026-05-19 Pablo Motta , Filipe B. Abdalla , Elcio Abdalla , Gabriel S. Costa , Camila Cardoso

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…

Instrumentation and Methods for Astrophysics · Physics 2018-12-26 Johanna Pasquet , Emmanuel Bertin , Marie Treyer , Stéphane Arnouts , Dominique Fouchez

The Sloan Digital Sky Survey-II (SDSS-II) has embarked on a multi-year project to identify and measure light curves for intermediate-redshift (0.05 < z < 0.35) Type Ia supernovae (SNe Ia) using repeated five-band (ugriz) imaging over an…

The new generation of deep photometric surveys requires unprecedentedly precise shape and photometry measurements of billions of galaxies to achieve their main science goals. At such depths, one major limiting factor is the blending of…

The Wide-Area VISTA Extragalactic Survey (WAVES) on the 4-metre Multi-Object Spectroscopic Telescope (4MOST) includes two flux-limited subsurveys with very high (95\%) completeness requirements: Wide over $\sim\!1200$ deg$^2$ and Deep over…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-14 G. Kaur , M. Bilicki , S. Bellstedt , E. Tempel , W. A. Hellwing , I. Baldry , B. Bandi , S. Barsanti , S. Driver , N. Guerra-Varas , B. Holwerda , C. Lagos , J. Loveday , A. Robotham

Mergers are an important aspect of galaxy formation and evolution. We aim to test whether deep learning techniques can be used to reproduce visual classification of observations, physical classification of simulations and highlight any…

Astrophysics of Galaxies · Physics 2019-06-12 W. J. Pearson , L. Wang , J. W. Trayford , C. E. Petrillo , F. F. S. van der Tak

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…

Instrumentation and Methods for Astrophysics · Physics 2019-08-27 Radamanthys Stivaktakis , Grigorios Tsagkatakis , Bruno Moraes , Filipe Abdalla , Jean-Luc Starck , Panagiotis Tsakalides