English
Related papers

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

200 papers

Metal absorption line systems in distant quasar spectra probe of the history of gas content in the universe. The MgII $\lambda \lambda$ 2796, 2803 doublet is one of the most important absorption lines since it is a proxy of the star…

Astrophysics of Galaxies · Physics 2019-05-07 Yinan Zhao , Jian Ge , Xiaoyong Yuan , Tiffany Zhao , Cindy Wang , Xiaolin Li

Quasar absorption line analysis is critical for studying gas and dust components and their physical and chemical properties as well as the evolution and formation of galaxies in the early universe. Ca II absorbers, which are one of the…

Astrophysics of Galaxies · Physics 2022-10-18 Iona Xia , Jian Ge , Kevin Willis , Yinan Zhao

Automated spectral classification is an active research area in astronomy at the age of data explosion. While new generation of sky survey telescopes (e.g. LAMOST and SDSS) produce huge amount of spectra, automated spectral classification…

Instrumentation and Methods for Astrophysics · Physics 2018-01-17 Yihan Tao , Yanxia Zhang , Chenzhou Cui , Ge Zhang

(abridged) We describe the automated spectral classification, redshift determination, and parameter measurement pipeline in use for the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III (SDSS-III) as of Data…

We present a Principal Component Analysis (PCA)-based spectral classification, eta, for the first 5600 galaxies observed in the DEEP2 Redshift Survey. This parameter provides a very pronounced separation between absorption and emission…

Photometric redshift estimation is a key requirement for modern large-area surveys, where spectroscopic measurements are observationally prohibitive. Seyfert II galaxies provide a particularly challenging test case due to the combined…

Astrophysics of Galaxies · Physics 2026-04-23 Uzay Aydin

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

We calculate photometric redshifts from the Sloan Digital Sky Survey Main Galaxy Sample, The Galaxy Evolution Explorer All Sky Survey, and The Two Micron All Sky Survey using two new training-set methods. We utilize the broad-band…

Astrophysics · Physics 2008-11-26 M. J. Way , A. N. Srivastava

We present a systematic search for wide-separation (Einstein radius >1.5"), galaxy-scale strong lenses in the 30 000 sq.deg of the Pan-STARRS 3pi survey on the Northern sky. With long time delays of a few days to weeks, such systems are…

Astrophysics of Galaxies · Physics 2021-04-08 R. Canameras , S. Schuldt , S. H. Suyu , S. Taubenberger , T. Meinhardt , L. Leal-Taixe , C. Lemon , K. Rojas , E. Savary

To reduce data collection time for deep learning of robust robotic grasp plans, we explore training from a synthetic dataset of 6.7 million point clouds, grasps, and analytic grasp metrics generated from thousands of 3D models from Dex-Net…

Spectroscopic surveys require fast and efficient analysis methods to maximize their scientific impact. Here we apply a deep neural network architecture to analyze both SDSS-III APOGEE DR13 and synthetic stellar spectra. When our…

Instrumentation and Methods for Astrophysics · Physics 2018-02-21 Sebastien Fabbro , Kim Venn , Teaghan O'Briain , Spencer Bialek , Collin Kielty , Farbod Jahandar , Stephanie Monty

We apply machine learning in the form of a nearest neighbor instance-based algorithm (NN) to generate full photometric redshift probability density functions (PDFs) for objects in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS…

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…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-21 Kevin M. Quigley , Samuel Hori , Rupert A. C. Croft

The next generation of wide-field deep astronomical surveys will deliver unprecedented amounts of images through the 2020s and beyond. As both the sensitivity and depth of observations increase, more blended sources will be detected. This…

Instrumentation and Methods for Astrophysics · Physics 2024-12-02 G. M. Merz , Y. Liu , C. J. Burke , P. D. Aleo , X. Liu , M. C. Kind , V. Kindratenko , Y. Liu

We provide classifications for all 143 million non-repeat photometric objects in the Third Data Release of the Sloan Digital Sky Survey (SDSS) using decision trees trained on 477,068 objects with SDSS spectroscopic data. We demonstrate that…

Astrophysics · Physics 2008-11-26 Nicholas M. Ball , Robert J. Brunner , Adam D. Myers , David Tcheng

Time-domain surveys such as the Zwicky Transient Facility (ZTF) have opened a new frontier in the discovery and characterization of transients. While photometric light curves provide broad temporal coverage, spectroscopic observations…

Millions of quasar spectra will be collected by the Dark Energy Spectroscopic Instrument (DESI), leading to a four-fold increase in the number of known quasars. High accuracy quasar classification is essential to tighten constraints on…

At high redshift, due to both observational limitations and the variety of galaxy morphologies in the early universe, measuring galaxy structure can be challenging. Non-parametric measurements such as the CAS system have thus become an…

Astrophysics of Galaxies · Physics 2021-09-08 C. Tohill , L. Ferreira , C. J. Conselice , S. P. Bamford , F. Ferrari

Over the next few years new spectroscopic surveys (from the optical surveys of the Sloan Digital Sky Survey and the 2 degree Field survey through to space-based ultraviolet satellites such as GALEX) will provide the opportunity and…

Astrophysics · Physics 2009-10-31 A. J. Connolly , A. S. Szalay

Accurate photometric redshift estimation is critical for observational cosmology, especially in large-scale surveys where spectroscopic measurements are impractical. Traditional approaches include template fitting and machine learning, each…

Instrumentation and Methods for Astrophysics · Physics 2026-04-15 Jonas Chris Ferrao , Dickson Dias , Pranav Naik , Glory D'Cruz , Anish Naik , Siya Khandeparkar , Manisha Gokuldas Fal Dessai