Galaxy Zoo: Passive Red Spirals (2009)
Masters, Karen L., Mosleh, Moein, Romer, A. Kathy, Nichol, Robert C., Bamford, Steven P., Schawinski, Kevin, ...
We study the spectroscopic properties and environments of red spiral galaxies found by the Galaxy Zoo project. By carefully selecting face-on, disk dominated spirals we construct a sample of truly...
Galaxy Zoo: Reproducing Galaxy Morphologies Via Machine Learning (2009)
Banerji, Manda, Lahav, Ofer, Lintott, Chris J., Abdalla, Filipe B., Schawinski, Kevin, Andreescu, Dan, ...
We present morphological classifications obtained using machine learning for objects in SDSS DR7 that have been classified by Galaxy Zoo into three classes namely spirals, ellipticals and...
CMB Lensing Constraints on Dark Energy and Modified Gravity Scenarios (2009)
Calabrese, Erminia, Cooray, Asantha, Martinelli, Matteo, Melchiorri, Alessandro, Pagano, Luca, Slosar, Anze, ...
Weak gravitational lensing leaves a characteristic imprint on the cosmic microwave background temperature and polarization angular power spectra. Here we investigate the possible constraints on the...
Galaxy Zoo Green Peas: Discovery of A Class of Compact Extremely Star-Forming Galaxies (2009)
Cardamone, Carolin N., Schawinski, Kevin, Sarzi, Marc, Bamford, Steven P., Bennert, Nicola, Urry, C. M., ...
We investigate a class of rapidly growing emission line galaxies, known as "Green Peas", first noted by volunteers in the Galaxy Zoo project because of their peculiar bright green colour and small...
Galaxy Zoo : 'Hanny's Voorwerp', a quasar light echo? (2009)
Lintott, Chris, Schawinski, Kevin, Keel, William, Van Arkel, Hanny, Bennert, Nicola, Edmondson, Edward, ...
We report the discovery of an unusual object near the spiral galaxy IC 2497, discovered by visual inspection of the Sloan Digital Sky Survey (SDSS) as part of the Galaxy Zoo project. The object,...
Jimenez, Raul, Slosar, Anze, Verde, Licia, Bamford, Steven, Lintott, Chris, Schawinski, Kevin, ...
We report on the finding of a correlation between galaxies' past star formation activity and the degree to which neighbouring galaxies rotation axes are aligned. This is obtained by cross-correlating...
Galaxy Zoo: A sample of blue early-type galaxies at low redshift (2009)
Schawinski, Kevin, Lintott, Chris, Thomas, Daniel, Sarzi, Marc, Andreescu, Dan, Bamford, Steven P., ...
We report the discovery of a population of nearby, blue early-type galaxies with high star formation rates (0.5 < SFR < 50 Msun/yr). They are identified by their visual morphology as provided by...
Scale-dependent bias from primordial non-Gaussianity in general relativity (2009)
In this note we examine the derivation of scale-dependent bias due to primordial non-Gaussianity of the local type in the context of general relativity. We justify the use of the Poisson equation in...
Galaxy Zoo: a sample of blue early-type galaxies at low redshift (2009)
Schawinski, Kevin, Lintott, Chris, Thomas, Daniel, Sarzi, Marc, Andreescu, Dan, Bamford, Steven P., ...
Galaxy Zoo: Disentangling the Environmental Dependence of Morphology and Colour (2008)
Skibba, Ramin A., Bamford, Steven P., Nichol, Robert C., Lintott, Chris J., Andreescu, Dan, Edmondson, Edward M., ...
We analyze the environmental dependence of galaxy morphology and colour with two-point clustering statistics, using data from the Galaxy Zoo, the largest sample of visually classified morphologies...
Alignment of galaxy spins in the vicinity of voids (2008)
We provide limits on the alignment of galaxy orientations with the direction to the void center for galaxies lying near the edges of voids. We locate spherical voids in volume limited samples of...
Melchiorri, Alessandro, Mena, Olga, Palomares-Ruiz, Sergio, Pascoli, Silvia, Slosar, Anze, Sorel, Michel
Light sterile neutrinos might mix with the active ones and be copiously produced in the early Universe. In the present paper, a detailed multi-flavor analysis of sterile neutrino production is...
Galaxy Zoo: Chiral correlation function of galaxy spins (2008)
Slosar, Anze, Land, Kate, Bamford, Steven, Lintott, Chris, Andreescu, Dan, Murray, Phil, ...
Galaxy Zoo is the first study of nearby galaxies that contains reliable information about the spiral sense of rotation of galaxy arms for a sizeable number of galaxies. We measure the correlation...
Optimal dataset combining in f_nl constraints from large scale structure in an idealised case (2008)
We consider the problem of optimal weighting of tracers of structure for the purpose of constraining the non-Gaussianity parameter f_NL. We work within the Fisher matrix formalism expanded around...
Constraints on local primordial non-Gaussianity from large scale structure (2008)
Slosar, Anze, Hirata, Christopher, Seljak, Uros, Ho, Shirley, Padmanabhan, Nikhil
Recent work has shown that the local non-Gaussianity parameter f_NL induces a scale-dependent bias, whose amplitude is growing with scale. Here we first rederive this result within the context of...
Galaxy Zoo: the dependence of morphology and colour on environment (2008)
Bamford, Steven P., Nichol, Robert C., Baldry, Ivan K., Land, Kate, Lintott, Chris J., Schawinski, Kevin, ...
We analyse the relationships between galaxy morphology, colour, environment and stellar mass using data for over 100,000 objects from Galaxy Zoo, the largest sample of visually classified...
Lintott, Chris J., Schawinski, Kevin, Slosar, Anze, Land, Kate, Bamford, Steven, Thomas, Daniel, ...
In order to understand the formation and subsequent evolution of galaxies one must first distinguish between the two main morphological classes of massive systems: spirals and early-type systems....
Land, Kate, Slosar, Anze, Lintott, Chris, Andreescu, Dan, Bamford, Steven, Murray, Phil, ...
We re-examine the evidence for a violation of large-scale statistical isotropy in the distribution of projected spin vectors of spiral galaxies. We have a sample of $\sim 37,000$ spiral galaxies from...
Cosmic Microwave Weak lensing data as a test for the dark universe (2008)
Calabrese, Erminia, Slosar, Anze, Melchiorri, Alessandro, Smoot, George F., Zahn, Oliver
Combined analyses of WMAP 3-year and ACBAR Cosmic Microwave Anisotropies angular power spectra have presented evidence for gravitational lensing >3 sigma level. This signal could provide a relevant...
Gordon, Christopher, Land, Kate, Slosar, Anze
We estimate the solar system motion relative to the cosmic microwave background using type Ia supernovae (SNe) measurements. We take into account the correlations in the error bars of the SNe...
Correlation between galactic HI and the Cosmic Microwave Background (2007)
We revisit the issue of a correlation between the atomic hydrogen gas in our local Galaxy and the Cosmic Microwave Background (CMB), a detection of which has been claimed in some literature. We...
An improved cosmological bound on the thermal axion mass (2007)
Melchiorri, Alessandro, Mena, Olga, Slosar, Anze
Relic thermal axions could play the role of an extra hot dark matter component in cosmological structure formation theories. By combining the most recent observational data we improve previous...
Cosmological Constraints from Type Ia Supernovae Peculiar Velocity Measurements (2007)
Gordon, Christopher, Land, Kate, Slosar, Anze
We detect the correlated peculiar velocities of nearby type Ia supernovae (SNe), while highlighting an error in some of the literature. We find sigma_8=0.79 +/- 0.22 from SNe, and examine the...
Cross-correlation studies as a probe of reionization physics (2007)
Slosar, Anze, Cooray, Asantha, Silk, Joseph
The process of reionization is now believed to have proceeded in an orchestrated manner beginning with UV photons emitted by high redshift galaxies containing a large fraction of Population III stars...
New Constraints on Oscillations in the Primordial Spectrum of Inflationary Perturbations (2007)
Hamann, Jan, Covi, Laura, Melchiorri, Alessandro, Slosar, Anze
We revisit the problem of constraining steps in the inflationary potential with cosmological data. We argue that a step in the inflationary potential produces qualitatively similar oscillations in...
Mangano, Gianpiero, Melchiorri, Alessandro, Mena, Olga, Miele, Gennaro, Slosar, Anze
We discuss the present bounds on the relativistic energy density in the Universe parameterized in terms of the effective number of neutrinos N using the most recent cosmological data on Cosmic...
On the connected-charges Thomson problem (2006)
Slosar, Anze, Podgornik, Rudolf
We investigate the modifications brought about by the linear connectivity among charges in the classical Thomson problem. Instead of packing with local hexagonal order intersperced with topological...
Inflation and WMAP three year data: Features have a Future! (2006)
Covi, Laura, Hamann, Jan, Melchiorri, Alessandro, Slosar, Anze, Sorbera, Irene
The new three year WMAP data seem to confirm the presence of non-standard large scale features in the Cosmic Microwave Anisotropies power spectrum. While these features may hint at uncorrected...
Seljak, Uros, Slosar, Anze, McDonald, Patrick
We combine the Ly-alpha forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including 3-year WMAP, and supernovae...
B polarization of cosmic microwave background as a tracer of strings (2006)
String models can produce successful inflationary scenarios in the context of brane collisions and in many of these models cosmic strings may also be produced. In scenarios such as KKLMMT the string...
Non-Gaussianity in the Very Small Array CMB maps with Smooth-Goodness-of-fit tests (2006)
Rubino-Martin, Jose Alberto, Aliaga, Antonio M., Barreiro, R. B., Battye, Richard A., Carreira, Pedro, Cleary, Kieran, ...
(Abridged) We have used the Rayner & Best (1989) smooth tests of goodness-of-fit to study the Gaussianity of the Very Small Array (VSA) data. Out of the 41 published VSA individual pointings...
Detecting neutrino mass difference with cosmology (2006)
Cosmological parameter estimation exercises usually make the approximation that the three standard neutrinos have degenerate mass, which is at odds with recent terrestrial measurements of the...
Is cosmology compatible with sterile neutrinos? (2005)
Dodelson, Scott, Melchiorri, Alessandro, Slosar, Anze
By combining data from cosmic microwave background (CMB) experiments (including the recent WMAP third year results), large scale structure (LSS) and Lyman-alpha forest observations, we constrain the...
Did Boomerang hit MOND? (2005)
Slosar, Anze, Melchiorri, Alessandro, Silk, Joseph
Purely baryonic dark matter dominated models like MOND based on modification of Newtonian gravity have been successfully in reproducing some dynamical properties of galaxies. More recently, a...
Pairwise velocities in the Halo Model: Luminosity and Scale Dependence (2005)
Slosar, Anze, Seljak, Uros, Tasitsiomi, Argyro
We investigate the properties of the pairwise velocity dispersion as a function of galaxy luminosity in the context of a halo model. We derive the distribution of velocities of pairs at a given...
Source subtraction for the extended Very Small Array and 33-GHz source count estimates (2004)
Cleary, Kieran A., Taylor, Angela C., Waldram, Elizabeth, Battye, Richard A., Dickinson, Clive, Davies, Rod D., ...
We describe the source subtraction strategy and observations for the extended Very Small Array, a CMB interferometer operating at 33 GHz. A total of 453 sources were monitored at 33 GHz using a...
Bayesian evidence as a tool for comparing datasets (2004)
Marshall, Phil, Rajguru, Nutan, Slosar, Anze
We introduce a new conservative test for quantifying the consistency of two or more datasets. The test is based on the Bayesian answer to the question, ``How much more probable is it that all my data...
Assessing the effects of foregrounds and sky removal in WMAP (2004)
Many recent analyses have indicated that large scale WMAP data display anomalies that appear inconsistent with the standard cosmological paradigm. However, the effects of foreground contamination,...
High sensitivity measurements of the CMB power spectrum with the extended Very Small Array (2004)
Dickinson, Clive, Battye, Richard A., Cleary, Kieran, Davies, Rod D., Davis, Richard J., Genova-Santos, Ricardo, ...
We present deep Ka-band ($\nu \approx 33$ GHz) observations of the CMB made with the extended Very Small Array (VSA). This configuration produces a naturally weighted synthesized FWHM beamwidth of...
Cosmological parameter estimation using Very Small Array data out to l=1500 (2004)
Rebolo, Rafael, Battye, Richard A., Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., ...
We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other CMB data and external priors. Within the...
Estimating the bispectrum of the Very Small Array data (2004)
Smith, Sarah, Rocha, Graca, Challinor, Anthony, Battye, Richard A., Carreira, Pedro, Cleary, Kieran, ...
We estimate the bispectrum of the Very Small Array data from the compact and extended configuration observations released in December 2002, and compare our results to those obtained from Gaussian...
Searching for non-Gaussianity in the VSA data (2003)
Savage, Richard, Battye, Richard A., Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., ...
We have tested Very Small Array (VSA) observations of three regions of sky for the presence of non-Gaussianity, using high-order cumulants, Minkowski functionals, a wavelet-based test and a Bayesian...
Markov-chain Monte Carlo sampling has become a standard technique for exploring the posterior distribution of cosmological parameters constrained by observations of CMB anisotropies. Given an...
The CMB power spectrum out to l=1400 measured by the VSA (2002)
Grainge, Keith, Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., Dickinson, Clive, ...
We have observed the cosmic microwave background (CMB) in three regions of sky using the Very Small Array (VSA) in an extended configuration with antennas of beamwidth 2 degrees at 34 GHz. Combined...
Cosmological parameter estimation and Bayesian model comparison using VSA data (2002)
Slosar, Anze, Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., Dickinson, Clive, ...
We constrain the basic comological parameters using the first observations by the Very Small Array (VSA) in its extended configuration, together with existing cosmic microwave background data and...
First results from the Very Small Array -- IV. Cosmological parameter estimation (2002)
Rubino-Martin, Jose Alberto, Rebolo, Rafael, Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., ...
We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard...
First results from the Very Small Array -- I. Observational methods (2002)
Watson, Robert A., Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., Dickinson, Clive, ...
The Very Small Array (VSA) is a synthesis telescope designed to image faint structures in the cosmic microwave background on degree and sub-degree angular scales. The VSA has key differences from...
First results from the Very Small Array -- III. The CMB power spectrum (2002)
Scott, Paul F., Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard, Dickinson, Clive, ...
We present the power spectrum of the fluctuations in the cosmic microwave background detected by the Very Small Array (VSA) in its first season of observations in its compact configuration. We find...
First results from the Very Small Array -- II. Observations of the CMB (2002)
Taylor, Angela C., Carreira, Pedro, Cleary, Kieran, Davies, Rod D., Davis, Richard J., Dickinson, Clive, ...
We have observed the cosmic microwave background temperature fluctuations in eight fields covering three separated areas of sky with the Very Small Array at 34 GHz. A total area of 101 square degrees...