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We present Hubble Space Telescope images of 11 high redshift radio galaxies (between $z=2.3$ and $z=3.6$). The galaxies were observed with the WFPC2 camera in a broad band filter (F606W or F707W, roughly equivalent to V or R-band), for 2…

We study the clustering of galaxies in real and redshift space using the Optical Redshift Survey (ORS). We estimate the two point correlation function in redshift space, $\xi(s)$, for several subsamples of ORS, spanning nearly a factor of…

The observed large-scale alignment of polarization angles and galaxy axis have been challenging the fundamental assumption of homogeneity and isotropy in standard cosmology since more than two decades. The intergalactic magnetic field, and…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-07 Prabhakar Tiwari , Pankaj Jain

We present measurements of the small-scale (0.1<~ r <~ 1 Mpc/h) quasar two-point correlation function at z>2.9, for a flux-limited (i<21) sample of 15 binary quasars compiled by Hennawi et al. (2009). The amplitude of the small-scale…

We constructed and presented in the first paper of this series a new sample of 84 large angular size radio galaxies by selecting from the NRAO VLA Sky Survey objects with angular size > 4', declination above +60 degrees and total flux…

Astrophysics · Physics 2009-11-07 L. Lara , I. Marquez , W. D. Cotton , L. Feretti , G. Giovannini , J. M. Marcaide , T. Venturi

We have studied galaxy two-point angular correlations as a function of color using 4-m plate photometry in two independent fields. Each field consists of over 2900 galaxies with magnitudes 20<B_J <23.5 in an area of approximately 750…

Astrophysics · Physics 2009-10-28 Stephen D. Landy , Alexander S. Szalay , David C. Koo

The angular cross-correlation between two galaxy samples separated in redshift is shown to be a useful measure of weak lensing by large-scale structure. Angular correlations in faint galaxies arise due to spatial clustering of the galaxies…

Astrophysics · Physics 2020-11-25 R. Moessner , Bhuvnesh Jain

We present new estimates of the spatial two-point correlation function of rich clusters of galaxies selected from the APM Galaxy Survey. We have measured redshifts for a sample of $364$ clusters out to a depth of $\sim 450\hmpc$. The…

Astrophysics · Physics 2016-06-08 G. B. Dalton , R. A. C. Croft , G. Efstathiou , W. J. Sutherland , S. J. Maddox , M. Davis

Radio measurements of rich Abell clusters of galaxies have been collected both from radio source catalogues and dedicated publications. By gathering these data for every cluster, complemented by optical data, an overall picture of each…

Astrophysics · Physics 2007-05-23 A. G. Gubanov , H. Andernach

We analyze the uncertainties in the amplitudes of the spatial correlation functions estimated from angular correlations in a sample from the APM Galaxy Survey, with $b_J=17-20$. We model the uncertainties in the selection function and in…

Astrophysics · Physics 2009-10-28 Enrique Gaztañaga

For faint photometric surveys our ability to quantify the clustering of galaxies has depended on interpreting the angular correlation function as a function of the limiting magnitude of the data. Due to the broad redshift distribution of…

Astrophysics · Physics 2009-10-30 A. J. Connolly , A. S. Szalay , R. J. Brunner

We study the alignment of radio galaxies axes using the FIRST catalogue. we impose several cuts in order to select the candidates which are most likely to be free of systematic bias. In our study we primarily focus on testing for alignment…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-07 Mohit Panwar , Prabhakar , Pritpal Kaur Sandhu , Yogesh Wadadekar , Pankaj Jain

While it is well known that galaxies are composites of many emission processes, quantifying the various contributions remains challenging. In this work, we use unsupervised machine learning based clustering algorithms to evaluate the…

Two-point correlation functions (2PCF) are widely used to characterize how points cluster in space. In this work, we study the problem of measuring the 2PCF over a large set of points, restricted to a subset satisfying a property of…

Computer Vision and Pattern Recognition · Computer Science 2026-04-08 Max Hamilton , Daniel Sheldon , Subhransu Maji

A new method for a simultaneous search for clusters of galaxies in X-ray photon maps and optical galaxy maps is described. The merging of X-ray and optical data improves the source identification so that a large amount of telescope time for…

Astrophysics · Physics 2009-11-10 Peter Schuecker , Hans Boehringer , Wolfgang Voges

We present early results from Radio Galaxy Zoo, a web-based citizen science project for visual inspection and classification of images from all-sky radio surveys. The goals of the project are to classify individual radio sources…

Astrophysics of Galaxies · Physics 2016-03-09 Kyle W. Willett

We explore the cosmological constraints expected from wide area XMM-type cluster surveys covering 50-200 deg2, under realistic observing conditions. We perform a Fisher matrix analysis based on cluster number counts in combination with…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-26 M. Pierre , F. Pacaud , J. B. Juin , J. B. Melin , N. Clerc , P. S. Corasaniti

We present deep 1.4GHz Very Large Array (VLA) radio continuum observations of two ~half square degree fields in the Coma cluster of galaxies. The two fields, "Coma 1" and "Coma 3," correspond to the cluster core and southwest infall region…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Neal A. Miller , Ann E. Hornschemeier , Bahram Mobasher

Star formation in galaxies is observed to be associated with gamma-ray emission. The detection of gamma rays from star-forming galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship…

High Energy Astrophysical Phenomena · Physics 2012-08-07 Emma Storm , Tesla E. Jeltema , Stefano Profumo

We analyze the clustering of photometrically selected galaxy pairs by using the halo-occupation distribution (HOD) model. We measure the angular two-point auto-correlation function, $\omega(\theta)$, for galaxies and galaxy pairs in three…

Astrophysics of Galaxies · Physics 2015-06-22 Yiran Wang , R. J. Brunner
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