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We present a stacked weak lensing analysis of 27 richness selected galaxy clusters at $0.40 \leqslant z \leqslant 0.62$ in the CODEX survey. The fields were observed in 5 bands with the CFHT. We measure the stacked surface mass density…

We present a novel approach to reconstruct gas and dark matter projected density maps of galaxy clusters using score-based generative modeling. Our diffusion model takes in mock SZ and X-ray images as conditional inputs, and generates…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-16 Alan Hsu , Matthew Ho , Joyce Lin , Carleen Markey , Michelle Ntampaka , Hy Trac , Barnabás Póczos

The Bayesian gravitational shear estimation algorithm developed by Bernstein and Armstrong (2014) can potentially be used to overcome multiplicative noise bias and recover shear using very low signal-to-noise ratio (S/N) galaxy images. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Erin S. Sheldon

We present a two-dimensional (2-D) fitting algorithm (GALFIT, Version 3) with new capabilities to study the structural components of galaxies and other astronomical objects in digital images. Our technique improves on previous 2-D fitting…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Chien Y. Peng , Luis C. Ho , Chris D. Impey , Hans-Walter Rix

We present an extensive catalog of non-parametric structural properties derived from optical and mid-infrared imaging for 4585 galaxies from the MaNGA survey. DESI and WISE imaging are used to extract surface brightness profiles in the g,…

Astrophysics of Galaxies · Physics 2021-06-01 Nikhil Arora , Connor Stone , Stéphane Courteau , Thomas H. Jarrett

We have conducted a galaxy survey based on low-resolution slitless spectra taken from the automated CFHT-Laval survey. We present redshift distributions for 522 galaxies distributed in 4 distinct regions of the sky. Redshifts are determined…

Astrophysics · Physics 2015-06-24 M. Beauchemin , E. F. Borra

While the Sersic profile family provide adequate fits for the surface brightness profiles of observed galaxies, the physical origin is unknown. We show that, if the cosmological density field are seeded by random gaussian fluctuations, as…

Astrophysics of Galaxies · Physics 2015-06-19 Renyue Cen

Next generation large sky surveys will observe up to billions of galaxies for which basic structural parameters are needed to study their evolution. This is a challenging task that, for ground-based observations, is complicated by seeing…

Astrophysics of Galaxies · Physics 2022-05-04 R. Li , N. R. Napolitano , N. Roy , C. Tortora , F. La Barbera , A. Sonnenfeld , C. Qiu , S. Liu

Classification of galactic morphologies is a crucial task in galactic astronomy, and identifying fine structures of galaxies (e.g., spiral arms, bars, and clumps) is an essential ingredient in such a classification task. However, seeing…

Instrumentation and Methods for Astrophysics · Physics 2021-03-30 Fang Kai Gan , Kenji Bekki , Abdolhosein Hashemizadeh

We propose a new technique, which we call the lens parallax method, to determine simultaneously the redshift distribution of the faint blue galaxies and the mass distribution of foreground clusters of galaxies. The method is based on…

Astrophysics · Physics 2007-05-23 Ramesh Narayan , Matthias Bartelmann

Next generation probes of dark matter and dark energy require high precision reconstruction of faint galaxy shapes from hundreds of dithered exposures. Current practice is to stack the images. While valuable for many applications, this…

Astrophysics · Physics 2008-08-27 J. A. Tyson , C. Roat , J. Bosch , D. Wittman

Many recent studies have demonstrated that scaling arguments, such as the so-called hierarchical {\em ansatz}, are extremely useful in understanding the statistical properties of weak gravitational lensing. This is especially true on small…

Astrophysics · Physics 2009-10-31 Dipak Munshi , Peter Coles

In the theory of structure formation, galaxies are biased tracers of the underlying matter density field. The statistical relation between galaxy and matter density field is commonly referred as galaxy bias. In this paper, we test the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Eric Jullo , Jason Rhodes , Alina Kiessling , James E. Taylor , Richard Massey , Joel Berge , Carlo Schimd , Jean-Paul Kneib , Nick Scoville

The local space density of galaxies as a function of their basic structural parameters --like luminosity, surface brightness and scalesize-- is still poorly known. Our poor knowledge is mainly the result of strong selection biases against…

Astrophysics · Physics 2007-05-23 Roelof S. de Jong , Cedric Lacey

We present a statistical method to derive the stellar density profiles of the Milky Way from spectroscopic survey data, taking into account selection effects. We assume that the selection function of the spectroscopic survey is based on…

Structural parameters (half-light radius $r_e$, mean effective surface brightness $<\mu>_e$, and Sersic index n) are derived for a sample of galaxies in the rich cluster AC 118 at z=0.31: so far the largest (N=93) sample of galaxies at…

Astrophysics · Physics 2009-11-07 F. La Barbera , G. Busarello , P. Merluzzi , M. Massarotti , M. Capaccioli

We perform a comprehensive investigation of the PSF smoothing effect on the measurement of concentration-related parameters ($C$, Gini, $M_{20}$) of high redshift galaxies in the HST and JWST surveys. Our sample contains massive galaxies…

Astrophysics of Galaxies · Physics 2024-06-05 Jia-Hui Wang , Zhao-Yu Li , Ming-Yang Zhuang , Luis C. Ho , Li-Min Lai

Weak lensing is emerging as a powerful observational tool to constrain cosmological models, but is at present limited by an incomplete understanding of many sources of systematic error. Many of these errors are multiplicative and depend on…

We propose a framework for compressive sensing of images with local distinguishable objects, such as stars, and apply it to solve a problem in celestial navigation. Specifically, let x be an N-pixel real-valued image, consisting of a small…

Computational Geometry · Computer Science 2012-08-14 Rishi Gupta , Piotr Indyk , Eric Price , Yaron Rachlin

We present new results on the evolution of rest-frame blue/UV sizes and Sersic indices of H$\alpha$-selected star-forming galaxies over the last 11 Gyrs. We investigate how the perceived evolution can be affected by a range of biases and…

Astrophysics of Galaxies · Physics 2017-01-25 Ana Paulino-Afonso , David Sobral , Fernando Buitrago , Jose Afonso