English
Related papers

Related papers: The Shapes of Galaxy Groups

200 papers

The DEEP2 project will obtain redshifts for ~60,000 galaxies between z~0.7-1.5 in a comoving volume of 7 10^6 Mpc/h^3 for an LCDM universe. The survey will map four separate 2 by 0.5 degree strips of the sky. To study the expected…

Astrophysics · Physics 2009-11-07 Alison L. Coil , Marc Davis , Istvan Szapudi

We investigate 3D density and weak lensing profiles of dark matter haloes predicted by a cosmology-rescaling algorithm for $N$-body simulations. We extend the rescaling method of Angulo & White (2010) and Angulo & Hilbert (2015) to improve…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Malin Renneby , Stefan Hilbert , Raúl E. Angulo

We show how observations of multiply-imaged quasars at high redshift can be used as a probe of dark matter clumps (subhalos with masses ~ 10^9 solar masses) within the virialized extent of more massive lensing halos. A large abundance of…

Astrophysics · Physics 2015-06-24 R. Benton Metcalf , Piero Madau

We introduce a method to quantify the quality-of-fit between data and observables depending on the large scale Galactic magnetic field. We combine WMAP5 polarized synchrotron data and Rotation Measures of extragalactic sources in a joint…

Astrophysics of Galaxies · Physics 2009-07-22 Ronnie Jansson , Glennys R. Farrar , Andre H. Waelkens , Torsten A. Ensslin

We present an angular power spectrum analysis of the 2MASS full release extended source catalogue. The main sample used includes 518,576 galaxies below an extinction-corrected magnitude of K=13.5 and limited to |b|>20. The power spectrum…

Astrophysics · Physics 2009-11-13 W. J. Frith , P. J. Outram , T. Shanks

The ShapeFit compression method has been shown to be a powerful tool to gain cosmological information from galaxy power spectra in an effective, model-independent way. Here we present its performance on the blind PT challenge mock products…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-09 Samuel Brieden , Héctor Gil-Marín , Licia Verde

We study intrinsic alignments (IA) of galaxy image shapes within the Illustris cosmic structure formation simulations. We investigate how IA correlations depend on observable galaxy properties such as stellar mass, apparent magnitude,…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-12 Stefan Hilbert , Dandan Xu , Peter Schneider , Volker Springel , Mark Vogelsberger , Lars Hernquist

The N-body dark matter (DM) simulations point that DM density profiles, e.g. the NFW halo, should be cuspy in its center, but observations disfavour this kind of DM profile. Here we consider whether the observed rotation curves "close" to…

Astrophysics of Galaxies · Physics 2014-11-04 Davi C. Rodrigues , Paulo L. de Oliveira , Julio C. Fabris , Gianfranco Gentile

Tests for the intrinsic shape of the luminosity distribution in elliptical galaxies are discussed, with an emphasis on the uncertainties. Recent determinations of the ellipticity frequency function imply a paucity of nearly spherical…

Astrophysics of Galaxies · Physics 2016-01-27 David Merritt

We derive single S\'ersic fits and bulge-disk decompositions for 13096 galaxies at redshifts z < 0.08 in the GAMA II equatorial survey regions in the Kilo-Degree Survey (KiDS) g, r and i bands. The surface brightness fitting is performed…

We simulated both the matter and light (galaxy) distributions in a wedge of the universe and calculated the gravitational lensing magnification caused by the mass along the line of sight of galaxies and galaxy groups identified in sky…

Astrophysics · Physics 2009-11-10 Antonio C. C. Guimarães , Adam D. Myers , Tom Shanks

We report the first detection of the halo ellipticities of galaxy clusters by applying the halo-shear-shear correlations (HSSC), without the necessity of major axis determination. We use the Fourier\_Quad shear catalog based on the Hyper…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Zhenjie Liu , Jun Zhang , Cong Liu , Hekun Li

We propose a simple geometrical mechanism for the flattening of galactic rotation curves, the local compression of field lines around their planes induced either by the presence of thin string-like objects at the centers of galaxies or by…

Astrophysics of Galaxies · Physics 2021-04-28 K. Zatrimaylov

We present a detailed analysis of the two-point correlation function, from the 2dF Galaxy Redshift Survey (2dFGRS). We estimate the redshift-space correlation function, xi(s), from which we measure the redshift-space clustering length,…

We present equations for the gravitational lensing flexion expected for an elliptical lens mass distribution. These can be reduced to one-dimensional finite integrals, thus saving significant computing time over a full two-dimensional…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. J. Hawken , S. L. Bridle

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

Two algorithms for the identification of galaxy groups from redshift surveys are tested by application to simulated data derived from N-body simulation. The accuracy of the membership assignments by these algorithms is studied in a…

Astrophysics · Physics 2009-10-22 James J. Frederic

Stars form in molecular complexes that are visible as giant clouds ($\sim 10^{5-6} \mathrm{M}_\odot$) in nearby galaxies and as giant clumps ($\sim 10^{8-9}\mathrm{M}_\odot$) in galaxies at redshifts $z\approx1$$-$$3$. Theoretical…

We present new Planetary Nebula Spectrograph observations of the ordinary elliptical galaxy NGC 4494, resulting in positions and velocities of 255 PNe out to 7 effective radii (25 kpc). We also present new wide-field surface photometry from…

Recent results from gravitational lensing are combined with new modeling of the stellar velocity distributions in nearby galaxies to probe the connection between the luminous and the dark matter in elliptical galaxies. From analysing a…

Astrophysics · Physics 2007-05-23 H. -W. Rix
‹ Prev 1 8 9 10 Next ›