English
Related papers

Related papers: Galaxy Modeling with Compound Elliptical Shapelets

200 papers

Calibrating the photometric redshifts of >10^9 galaxies for upcoming weak lensing cosmology experiments is a major challenge for the astrophysics community. The path to obtaining the required spectroscopic redshifts for training and…

Extremely accurate shape measurements of galaxy images are needed to probe dark energy properties with weak gravitational lensing surveys. To increase survey area with a fixed observing time and pixel count, images from surveys such as the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Charles Shapiro , Barnaby Rowe , Timothy Goodsall , Christopher M. Hirata , Jason Fucik , Jason Rhodes , Suresh Seshadri , Roger Smith

Weak gravitational lensing is a very sensitive way of measuring cosmological parameters, including dark energy, and of testing current theories of gravitation. In practice, this requires exquisite measurement of the shapes of billions of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 G. Nurbaeva , F. Courbin , M. Gentile , G. Meylan

The weak gravitational lensing effect, small coherent distortions of galaxy images by means of a gravitational tidal field, can be used to study the relation between the matter and galaxy distribution. In this context, weak lensing has so…

Astrophysics · Physics 2014-11-18 P. Simon , P. Watts , P. Schneider , H. Hoekstra , M. D. Gladders , H. K. C. Yee , B. C. Hsieh , H. Lin

The combination of strong gravitational lensing and stellar kinematics provides a powerful and robust method to investigate the mass and dynamical structure of early-type galaxies. We demonstrate this approach by analysing two massive…

Astrophysics of Galaxies · Physics 2015-06-22 Matteo Barnabè , Chiara Spiniello , Léon V. E. Koopmans

Although topological considerations amongst multiple labels have been previously investigated in the context of continuous max-flow image segmentation, similar investigations have yet to be made about shape considerations in a general and…

Computer Vision and Pattern Recognition · Computer Science 2015-10-19 John S. H. Baxter , Jing Yuan , Terry M. Peters

The discovery of a population of massive, compact and quiescent early-type galaxies has changed the view on plausible formation scenarios for the present day population of elliptical galaxies. Traditionally assumed formation histories…

Astrophysics of Galaxies · Physics 2015-06-12 Thorsten Naab

I describe a new, open-source astronomical image-fitting program called Imfit, specialized for galaxies but potentially useful for other sources, which is fast, flexible, and highly extensible. A key characteristic of the program is an…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Peter Erwin

We have developed a method based on wavelets to obtain the true underlying smooth density from a point distribution. The goal has been to reconstruct the density field in an optimal way ensuring that the morphology of the reconstructed…

Astrophysics · Physics 2009-11-13 V. J. Martinez , J. -L. Starck , E. Saar , D. L. Donoho , S. Reynolds , P. de la Cruz , S. Paredes

In this paper we analyse the relations between a previously described oblate Jaffe model for an ellipsoidal galaxy and the observed quantities for NGC 2974, and obtain the length and velocity scales for a relevant elliptical galaxy model.…

Astrophysics · Physics 2009-01-04 Zhenglu Jiang

There are strong correlations between the three structural properties of elliptical galaxies -- stellar mass, velocity dispersion and size -- in the form of a tight "fundamental plane" and a "scaling relation" between each pair. Major…

Astrophysics of Galaxies · Physics 2011-07-12 M. D. Covington , J. R. Primack , L. A. Porter , D. J. Croton , R. S. Somerville , A. Dekel

The intrinsic alignment of galaxies is an important systematic effect in weak-lensing surveys, which can affect the derived cosmological parameters. One direct way to distinguish different alignment models and quantify their effects on the…

We use the Galaxy Morphology Posterior Estimation Network (GaMPEN) to estimate morphological parameters and associated uncertainties for $\sim 8$ million galaxies in the Hyper Suprime-Cam (HSC) Wide survey with $z \leq 0.75$ and $m \leq…

The clustering of matter on cosmological scales is an essential probe for studying the physical origin and composition of our Universe. To date, most of the direct studies have focused on shear-shear weak lensing correlations, but it is…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-26 Tobias Baldauf , Robert E. Smith , Uros Seljak , Rachel Mandelbaum

While the direct detection of the dark-matter particle remains very challenging, the nature of dark matter could be possibly constrained by comparing the observed abundance and properties of small-scale sub-galactic mass structures with…

Astrophysics of Galaxies · Physics 2023-05-17 D. Bayer , L. V. E. Koopmans , J. P. McKean , S. Vegetti , T. Treu , C. D. Fassnacht , K. Glazebrook

We construct numerical models of mildly triaxial elliptical galaxies with central density cusps. Using a technique we call ``adiabatic squeezing'', we begin with a spherical gamma=1 Hernquist model and apply a drag to the velocities of the…

We explore the possibility that an intrinsic correlation between galaxy ellipticities arising during the galaxy formation process may account for part of the shear signal recently reported by several groups engaged in weak lensing surveys.…

Astrophysics · Physics 2009-07-28 Rupert A. C. Croft , Chris Metzler

In strong gravitational lens systems, the light bending is usually dominated by one main galaxy, but may be affected by other mass along the line of sight (LOS). Shear and convergence can be used to approximate the contributions from less…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-09 Curtis McCully , Charles R. Keeton , Kenneth C. Wong , Ann I. Zabludoff

This paper presents a sparse representation-based classification approach with a novel dictionary construction procedure. By using the constructed dictionary sophisticated prior knowledge about the spatial nature of the image can be…

Computer Vision and Pattern Recognition · Computer Science 2017-08-22 Ribana Roscher , Björn Waske

(ABRIDGED) We examine the fundamental scaling relations of elliptical galaxies formed through mergers. Using hundreds of simulations to judge the impact of progenitor galaxy properties on merger remnants, we find that gas dissipation…

Astrophysics · Physics 2009-07-09 B. Robertson , T. J. Cox , L. Hernquist , M. Franx , P. F. Hopkins , P. Martini , V. Springel
‹ Prev 1 8 9 10 Next ›