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Related papers: An Extendable Galaxy Number Count Model

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We consider cosmological applications of galaxy number density correlations to be inferred from future deep and wide multi-band optical surveys. We mostly focus on very large scales as a probe of possible features in the primordial power…

Astrophysics · Physics 2009-11-13 Hu Zhan , Lloyd Knox , J. Anthony Tyson , Vera Margoniner

Our knowledge of the Galaxy is being revolutionised by a series of photometric, spectroscopic and astrometric surveys. Already an enormous body of data is available from completed surveys, and data of ever increasing quality and richness…

Astrophysics of Galaxies · Physics 2015-05-27 James Binney

We propose a new method to estimate the photometric redshift of galaxies by using the full galaxy image in each measured band. This method draws from the latest techniques and advances in machine learning, in particular Deep Neural…

Instrumentation and Methods for Astrophysics · Physics 2016-06-16 Ben Hoyle

Modern astronomy relies on massive databases collected by robotic telescopes and digital sky surveys, acquiring data in a much faster pace than what manual analysis can support. Among other data, these sky surveys collect information about…

Instrumentation and Methods for Astrophysics · Physics 2018-10-29 Evan Kuminski , Lior Shamir

We present a multi-modal foundation model for astrophysical galaxy data, designed to map between simulation- and observation-based galactic features. Our encoder-only transformer flexibly ingests scalar quantities (e.g., redshifts, galaxy…

Astrophysics of Galaxies · Physics 2025-10-10 Bin Xia , Nesar Ramachandra , Azton I. Wells , Salman Habib , John Wise

The body of photometric and astrometric data on stars in the Galaxy has been growing very fast in recent years (Hipparcos/Tycho, OGLE-3, 2-Mass, DENIS, UCAC2, SDSS, RAVE, Pan Starrs, Hermes, ...) and in two years ESA will launch the Gaia…

Astrophysics of Galaxies · Physics 2009-11-16 James Binney

We present a collection of new, open-source computational tools for numerically modeling recent large-scale observational data sets using modern cosmology theory. Specifically, these tools will allow both students and researchers to…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-22 Jacob Moldenhauer , Larry Engelhardt , Keenan Stone , Ezekiel Shuler

We describe an improved, practical method for constructing galaxy models that match an arbitrary set of observational constraints, without prior assumptions about the phase-space distribution function (DF). Our method is an extension of…

Astrophysics · Physics 2009-10-31 Nicolas Cretton , P. Tim de Zeeuw , Roeland P. van der Marel , Hans-Walter Rix

The evolution of galaxy cluster counts is a powerful probe of several fundamental cosmological parameters. A number of recent studies using this probe have claimed tension with the cosmology preferred by the analysis of the Planck primary…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-21 C. E. Caldwell , I. G. McCarthy , I. K. Baldry , C. A. Collins , J. Schaye , S. Bird

Wide-field, multi-band surveys now detect millions of unresolved sources in nearby galaxy clusters, yet separating globular clusters (GCs) from foreground stars and background galaxies remains challenging. Scalable, automated classification…

Model fitting is frequently used to determine the shape of galaxies and the point spread function, for examples, in weak lensing analyses or morphology studies aiming at probing the evolution of galaxies. However, the number of parameters…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-03 Guoliang Li , Bo Xin , Wei Cui

Many different techniques to analyze galaxy clustering data and obtain cosmological constraints have been proposed, tested and used. Given the large amount of data that will be available soon, it is worth investigating new observables and…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-23 Eleonora Vanzan , Alvise Raccanelli , Nicola Bartolo

Image simulations are essential tools for preparing and validating the analysis of current and future wide-field optical surveys. However, the galaxy models used as the basis for these simulations are typically limited to simple parametric…

Instrumentation and Methods for Astrophysics · Physics 2021-05-12 Francois Lanusse , Rachel Mandelbaum , Siamak Ravanbakhsh , Chun-Liang Li , Peter Freeman , Barnabas Poczos

Galaxy number counts probe the evolution of galaxies over cosmic time, and serve as a valuable comparison point to theoretical models of galaxy formation. We present new galaxy number counts in eight photometric bands between 5 and 25…

We estimate the sensitivity of future galaxy surveys to cosmological parameters, using the redshift dependent angular power spectra of galaxy number counts, $C_\ell(z_1,z_2)$, calculated with all relativistic corrections at first order in…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-04 Enea Di Dio , Francesco Montanari , Ruth Durrer , Julien Lesgourgues

I briefly introduce a database of models that describe the evolution of star clusters in several broad-band photometric systems. Models are based on the latest Padova stellar evolutionary tracks - now including the alpha-enhanced case and…

Astrophysics · Physics 2007-05-23 Leo Girardi

The mass function of cluster-size halos and their redshift distribution are computed for 12 distinct accelerating cosmological scenarios and confronted to the predictions of the conventional flat $\Lambda$CDM model. The comparison with…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-27 S. Basilakos , M. Plionis , J. A. S. Lima

We present a new algorithm for efficiently computing the $N$-point correlation functions (NPCFs) of a 3D density field for arbitrary $N$. This can be applied both to a discrete spectroscopic galaxy survey and a continuous field. By…

Instrumentation and Methods for Astrophysics · Physics 2021-10-27 Oliver H. E. Philcox , Zachary Slepian , Jiamin Hou , Craig Warner , Robert N. Cahn , Daniel J. Eisenstein

We have developed a new model that uses a cellular approach to calculate radiative transfer of starlight through dusty media. The model is designed to be user friendly enough to be distributed as a tool for use by the general astronomical…

Astrophysics · Physics 2009-09-25 Matthew Trewhella , Barry F. Madore , Leslie Kuchinski

We study the prospects for measuring the cosmological distribution and abundance of ionized electrons in the intergalactic medium using galaxy surveys. Optical light from distant galaxies is subject to Thomson screening by intervening…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-18 Selim C. Hotinli , Gilbert P. Holder