English
Related papers

Related papers: Maximum Likelihood Random Galaxy Catalogues and Lu…

200 papers

We present a new approach to automate the spectroscopic redshift reliability assessment based on machine learning (ML) and characteristics of the redshift probability density function (PDF). We propose to rephrase the spectroscopic redshift…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 S. Jamal , V. Le Brun , O. Le Fèvre , D. Vibert , A. Schmitt , C. Surace , Y. Copin , B. Garilli , M. Moresco , L. Pozzetti

In a galaxy redshift survey the objects to be targeted for spectra are selected from a photometrically observed sample. The observed magnitudes and colours of galaxies in this parent sample will be affected by their peculiar velocities,…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-25 Shadab Alam , Rupert A. C. Croft , Shirley Ho , Hongyu Zhu , Elena Giusarma

Multi-distribution learning (MDL), which seeks to learn a shared model that minimizes the worst-case risk across $k$ distinct data distributions, has emerged as a unified framework in response to the evolving demand for robustness,…

Machine Learning · Computer Science 2025-08-12 Zihan Zhang , Wenhao Zhan , Yuxin Chen , Simon S. Du , Jason D. Lee

Obtaining well-calibrated photometric redshift probability densities for galaxies without a spectroscopic measurement remains a challenge. Deep learning discriminative models, typically fed with multi-band galaxy images, can produce outputs…

Instrumentation and Methods for Astrophysics · Physics 2024-11-27 Qiufan Lin , Hengxin Ruan , Dominique Fouchez , Shupei Chen , Rui Li , Paulo Montero-Camacho , Nicola R. Napolitano , Yuan-Sen Ting , Wei Zhang

Abridged] We present here new results on the space density of rich, optically-selected, clusters of galaxies at low redshift (z<0.15). These results are based on the application of the matched filter cluster-finding algorithm to 1067 deg2…

Astrophysics · Physics 2009-10-31 D. A. Bramel , R. C. Nichol , A. C. Pope

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-03 Juntao Ma , Jie Wang , Tianxiang Mao , Hongxiang Chen , Yuxi Meng , Xiaohu Yang , Qingyang Li

A combination of ground-based (NTT and VLT) and HST (HDF-N and HDF-S) public imaging surveys have been used to collect a sample of 1712 I-selected and 319 $K\leq 21$ galaxies. Photometric redshifts have been obtained for all these galaxies.…

Astrophysics · Physics 2009-10-31 A. Fontana , N. Menci , S. D'Odorico , E. Giallongo , F. Poli , S. Cristiani , A. Moorwood , P. Saracco

The colour bimodality of galaxies provides an empirical basis for theories of galaxy evolution. However, the balance of processes that begets this bimodality has not yet been constrained. A more detailed view of the galaxy population is…

Superclusters are the largest, observed matter density structures in the Universe. Recently Chon et al.(2013) presented the first supercluster catalogue constructed with a well-defined selection function based on the X-ray flux-limited…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Gayoung Chon , Hans Boehringer , Chris Collins , Martin Krause

The recent progress in obtaining larger and deeper galaxy catalogues is of fundamental importance for cosmological studies, especially to robustly measure the large scale density fluctuations in the Universe. The present work uses the…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Camila P. Novaes , Armando Bernui , Henrique S. Xavier , Gabriela A. Marques

One of the main problems of observational cosmology is to determine the range in which a reliable measurement of galaxy correlations is possible. This corresponds to determine the shape of the correlation function, its possible evolution…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Francesco Sylos Labini , Daniil Tekhanovich , Yurij V. Baryshev

Galaxy clustering measurements are a key probe of the matter density field in the Universe. With the era of precision cosmology upon us, surveys rely on precise measurements of the clustering signal for meaningful cosmological analysis.…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-25 Federico Berlfein , Rachel Mandelbaum , Scott Dodelson , Chad Schafer

In addition to the maximum likelihood approach, there are two other methods which are commonly used to reconstruct the true redshift distribution from photometric redshift datasets: one uses a deconvolution method, and the other a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Ravi K. Sheth , Graziano Rossi

Reliable extraction of cosmological information from clustering measurements of galaxy surveys requires estimation of the error covariance matrices of observables. The accuracy of covariance matrices is limited by our ability to generate…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-29 Mohammadjavad Vakili , Francisco-Shu Kitaura , Yu Feng , Gustavo Yepes , Cheng Zhao , Chia-Hsun Chuang , ChangHoon Hahn

RedGOLD searches for red-sequence galaxy overdensities while minimizing contamination from dusty star-forming galaxies. It imposes an NFW profile and calculates cluster detection significance and richness. We optimize these latter two…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-15 Rossella Licitra , Simona Mei , Anand Raichoor , Thomas Erben , Hendrik Hildebrandt

Massive high-redshift galaxies form in over-dense regions where the probability of forming other galaxies is also strongly enhanced. Given an observed flux of a galaxy, the inferred mass of its host halo tends to be larger as its inferred…

Astrophysics · Physics 2009-09-29 Joseph A. Muñoz , Abraham Loeb

This paper studies the connection between the relativistic number density of galaxies down the past light cone in a Friedmann-Lemaitre-Robertson-Walker spacetime with non-vanishing cosmological constant and the galaxy luminosity function…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-05 Alvaro S. Iribarrem , Amanda R. Lopes , Marcelo B. Ribeiro , William R. Stoeger

We constructed the composite Luminosity Function (LF) of cluster galaxies in the g,r and i bands from the photometry of a mixed (Abell and X-ray selected) sample of the cores of 65 clusters, ranging in redshift from 0.05 to 0.25. The…

Astrophysics · Physics 2010-11-04 Bianca Garilli , Dario Maccagni , Stefano Andreon
‹ Prev 1 8 9 10 Next ›