English
Related papers

Related papers: Recovering Physical Parameters from Galaxy Spectra…

200 papers

Using the MOPED algorithm we determine non-parametrically the Stellar Mass Function of 96,545 galaxies from the Sloan Digital Sky Survey data release one. By using the reconstructed spectrum due to starlight we can eliminate contamination…

Astrophysics · Physics 2009-11-10 Ben Panter , Alan Heavens , Raul Jimenez

We use automated surface photometry and pattern classification techniques to morphologically classify galaxies. The two-dimensional light distribution of a galaxy is reconstructed using Fourier series fits to azimuthal profiles computed in…

Astrophysics · Physics 2009-11-07 S. C. Odewahn , S. H. Cohen , R. A. Windhorst , N. S. Philip

We used 1627 faint (15.5< R<23) stars in five fields of the Calar Alto Deep Imaging Survey (CADIS) to estimate the structure parameters of the Galaxy. The results were derived by applying two complementary methods: first by fitting the…

Astrophysics · Physics 2009-11-11 S. Phleps , S. Drepper , K. Meisenheimer , B. Fuchs

Context: Massive amounts of spectroscopic data obtained by stellar surveys are feeding an ongoing revolution in our knowledge of stellar and Galactic astrophysics. Analysing these data sets to extract the best possible astrophysical…

Instrumentation and Methods for Astrophysics · Physics 2026-01-14 J. E. Martínez Fernández , S. Özdemir , R. Smiljanic , M. L. L. Dantas , A. R. da Silva

We describe a new approach for the determination of cosmological parameters using gravitational lensing systems with multiple arcs, exploiting the fact that a given cluster can produce multiple arcs from sources over a broad range in…

Astrophysics · Physics 2009-10-30 Robert Link , Michael J. Pierce

Contamination from galaxy fragments, identified as sources, is a major issue in large photometric galaxy catalogs. In this paper, we prove that this problem can be easily addressed with computer vision techniques. We use image cutouts to…

Astrophysics of Galaxies · Physics 2023-03-01 Enrico M. Di Teodoro , Josh E. G. Peek , John F. Wu

We study the possibility to extract model independent information about the dynamics of the universe by using Cosmography. We intend to explore it systematically, to learn about its limitations and its real possibilities. Here we are…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Salvatore Capozziello , Ruth Lazkoz , Vincenzo Salzano

We present a new approach to measure the shapes of galaxies, a fundamental task in observational astronomy. This approach is based on the decomposition of a galaxy image into a series of orthogonal basis functions, or `shapelets'. Our…

Astrophysics · Physics 2017-08-23 Alexandre Refregier , Tzu-Ching Chang , David Bacon

In recent years, deep learning approaches have achieved state-of-the-art results in the analysis of point cloud data. In cosmology, galaxy redshift surveys resemble such a permutation invariant collection of positions in space. These…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-23 Sotiris Anagnostidis , Arne Thomsen , Tomasz Kacprzak , Tilman Tröster , Luca Biggio , Alexandre Refregier , Thomas Hofmann

We present a novel approach for classifying star-forming galaxies using photometric images. By utilizing approximately $124,000$ optical color composite images and spectroscopic data of nearby galaxies at $0.01<z<0.06$ from the Sloan…

Astrophysics of Galaxies · Physics 2025-08-01 Kyuseok Oh , M. Dennis Turp

Stellar variability is driven by a multitude of internal physical processes that depend on fundamental stellar properties. These properties are our bridge to reconciling stellar observations with stellar physics, and for understanding the…

Solar and Stellar Astrophysics · Physics 2020-05-21 Kirsten Blancato , Melissa Ness , Daniel Huber , Yuxi Lu , Ruth Angus

We present a determination of the effects of including galaxy morphological parameters in photometric redshift estimation with an artificial neural network method. Neural networks, which recognize patterns in the information content of data…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 J. Singal , M. Shmakova , B. Gerke , R. L. Griffith , J. Lotz

State-of-the-art cosmological hydrodynamical simulations have star particles with typical mass between $\sim 10^8$ and $\sim 10^3$ M$_{\odot}$ according to resolution, and treat them as simple stellar populations. On the other hand,…

Astrophysics of Galaxies · Physics 2018-07-31 Milena Valentini , Alessandro Bressan , Stefano Borgani , Giuseppe Murante , Léo Girardi , Luca Tornatore

Gravitational lensing of distant galaxies can be exploited to infer the convergence field as a function of angular position on the sky. The statistics of this field, much like that of the cosmic microwave background (CMB), can be studied to…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 Hee-Jong Seo , Masanori Sato , Scott Dodelson , Bhuvnesh Jain , Masahiro Takada

Many approaches to obtaining cosmological constraints rely on the connection between galaxies and dark matter. However, the distribution of galaxies is dependent on their formation and evolution as well as the cosmological model, and galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Rachel Reddick , Jeremy Tinker , Risa Wechsler , Yu Lu

We present a new approach to constructing and fitting dipoles and higher-order multipoles in synthetic galaxy samples over the sky. Within our Bayesian paradigm, we illustrate that this technique is robust to masked skies, allowing us to…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-18 Oliver T. Oayda , Vasudev Mittal , Geraint F. Lewis

We study constraints that anticipated DEEP survey galaxy counts versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant $\Lambda$. This data will result…

Astrophysics · Physics 2011-07-19 Silviu Podariu , Bharat Ratra

We show that the growth curves of galaxies can be used to determine their bulge and disk parameters and bulge-to-total luminosity ratios, in addition to their conventional asymptotic magnitudes, provided that the point spread function is…

We present a novel method to search for structures of coherently aligned patterns in ultra-high energy cosmic-ray arrival directions simultaneously across the entire sky. This method can be used to obtain information on the Galactic…

Instrumentation and Methods for Astrophysics · Physics 2022-01-31 Marcus Wirtz , Teresa Bister , Martin Erdmann

We present an automated approach to detect and extract information from the astronomical datasets on the shapes of such objects as galaxies, star clusters and, especially, elongated ones such as the gravitational lenses. First, the…

Instrumentation and Methods for Astrophysics · Physics 2019-09-10 S. S. Mirzoyan , H. Khachatryan , G. Yegorian , V. G. Gurzadyan