January  June 2014
 Keplerian periodogram for Doppler exoplanet detection: optimized computation and analytic significance thresholds

Baluev, Roman V.
We consider the socalled Keplerian periodogram, in which the putative detectable signal is modelled by a highly nonlinear Keplerian radial velocity function, appearing in Doppler exoplanetary surveys. We demonstrate that for planets on higheccent ...  Generalized Fisher matrices

Heavens, A. F.; Seikel, M.; Nord, B. D.; Aich, M.; Bouffanais, Y.; Bassett, B. A.; Hobson, M. P.
The Fisher Information Matrix formalism (Fisher 1935) is extended to cases where the data are divided into two parts (X, Y), where the expectation value of Y depends on X according to some theoretical model, and X and Y both have errors with arbitra ...  Visualizing Astronomical Data with Blender

Kent, Brian R.
Astronomical data take on a multitude of forms  catalogs, data cubes, images, and simulations. The availability of software for rendering highquality threedimensional graphics lends itself to the paradigm of exploring the incredible parameter spa ...  DeBaCl: A Python Package for Interactive DEnsityBAsed CLustering

Kent, Brian P.; Rinaldo, Alessandro; Verstynen, Timothy
The level set tree approach of Hartigan (1975) provides a probabilistically based and highly interpretable encoding of the clustering behavior of a dataset. By representing the hierarchy of data modes as a dendrogram of the level sets of a density e ...  On the estimation of intensity for low S/N ratio narrow emission lines

Rola, C.; Pelat, D.
The aim of this paper is to investigate the errors involved by the intensity measure of low signaltonoise ratio narrow emission lines. We also studied the errors associated with line intensity ratios. The spectral data acquisition was simulated by ...  Sparse and NonNegative BSS for Noisy Data

Jérémy Rapin, Jérôme Bobin, Anthony Larue, JeanLuc Starck
Nonnegative blind source separation (BSS) has raised interest in various fields of research, as testified by the wide literature on the topic of nonnegative matrix factorization (NMF). In this context, it is fundamental that the sources to be esti ...  Joint Planck and WMAP CMB Map Reconstruction

J. Bobin, F. Sureau, J.L. Starck, A. Rassat, P. Paykari
We present a novel estimate of the cosmological microwave background (CMB) map by combining the two latest fullsky microwave surveys: WMAP nineyear and Planck PR1. The joint processing benefits from a recently introduced component separation metho ...  GLIMPSE: Accurate 3D weak lensing reconstructions using sparsity

Adrienne Leonard, François Lanusse, JeanLuc Starck
We present GLIMPSE  Gravitational Lensing Inversion and MaPping with Sparse Estimators  a new algorithm to generate density reconstructions in three dimensions from photometric weak lensing measurements. This is an extension of earlier work in one ...  Dark signal correction for a lukecold frametransfer CCD. New method and application to the solar imager of the PICARD space mission

Hochedez, J.F.; Timmermans, C.; Hauchecorne, A.; Meftah, M.
Context. Astrophysical observations must be corrected for their imperfections of instrumental origin. When chargecoupled devices (CCDs) are used, their dark signal is one such hindrance. In their pristine state, most CCD pixels are cool, that is, t ...  Flatrelative optimal extraction. A quick and efficient algorithm for stabilised spectrographs

Zechmeister, M.; AngladaEscudé, G.; Reiners, A.
Context. Optimal extraction is a key step in processing the raw images of spectra as registered by twodimensional detector arrays to a onedimensional format. Previously reported algorithms reconstruct models for a mean onedimensional spatial prof ...  Optimizing the search for transiting planets in long time series

Ofir, Aviv
Context. Transit surveys, both ground and spacebased, have already accumulated a large number of light curves that span several years. Aims: The search for transiting planets in these long time series is computationally intensive. We wish to opt ...  Optimized Principal Component Analysis on Coronagraphic Images of the Fomalhaut System

Meshkat, Tiffany; Kenworthy, Matthew A.; Quanz, Sascha P.; Amara, Adam
We present the results of a study to optimize the principal component analysis (PCA) algorithm for planet detection, a new algorithm complementing angular differential imaging and locally optimized combination of images (LOCI) for increasing the con ...  1SXPS: A Deep Swift XRay Telescope Point Source Catalog with Light Curves and Spectra

Evans, P. A.; Osborne, J. P.; Beardmore, A. P.; Page, K. L.; Willingale, R.; Mountford, C. J.; Pagani, C.; Burrows, D. N.; Kennea, J. A.; Perri, M.; Tagliaferri, G.; Gehrels, N.
We present the 1SXPS (SwiftXRT point source) catalog of 151,524 Xray point sources detected by the SwiftXRT in 8 yr of operation. The catalog covers 1905 deg2 distributed approximately uniformly on the sky. We analyze the data in two ways. First ...  Photometric classification of emission line galaxies with machinelearning methods

Cavuoti, Stefano; Brescia, Massimo; D'Abrusco, Raffaele; Longo, Giuseppe; Paolillo, Maurizio
In this paper, we discuss an application of machinelearningbased methods to the identification of candidate active galactic nucleus (AGN) from optical survey data and to the automatic classification of AGNs in broad classes. We applied four differ ...  Bayes versus the virial theorem: inferring the potential of a galaxy from a kinematical snapshot

Magorrian, John
We present a new framework for estimating a galaxy's gravitational potential, Φ, from its stellar kinematics by adopting a fully nonparametric model for the galaxy's unknown actionspace distribution function, f(J). Having an expression for the jo ...  Beyond stacking: a maximumlikelihood method to constrain radio source counts below the detection threshold

MitchellWynne, Ketron; Santos, Mário G.; Afonso, José; Jarvis, Matt J.
We present a statistical method based on a maximumlikelihood approach to constrain the number counts of extragalactic sources below the nominal fluxdensity limit of continuum imaging surveys. We extract flux densities from a radio map using positi ...  Enabling nonparametric strong lensing models to derive reliable cluster mass distributions  WSLAP+

Sendra, Irene; Diego, Jose M.; Broadhurst, Tom; Lazkoz, Ruth
In the strong lensing regime, nonparametric models struggle to achieve sufficient angular resolution for a meaningful derivation of the central cluster mass distribution. Cluster members perturb lensed images and generate additional images, requiri ...  TEMPONEST: a Bayesian approach to pulsar timing analysis

Lentati, L.; Alexander, P.; Hobson, M. P.; Feroz, F.; van Haasteren, R.; Lee, K. J.; Shannon, R. M.
A new Bayesian software package for the analysis of pulsar timing data is presented in the form of TEMPONEST which allows for the robust determination of the nonlinear pulsar timing solution simultaneously with a range of additional stochastic para ...  Bayesian lensing shear measurement

Bernstein, Gary M.; Armstrong, Robert
We derive an estimator of weak gravitational lensing shear from background galaxy images that avoids noiseinduced biases through a rigorous Bayesian treatment of the measurement. The derived shear estimator disposes with the assignment of elliptici ...  Hierarchical reverberation mapping

Brewer, Brendon J.; Elliott, Tom M.
Reverberation mapping (RM) is an important technique in studies of active galactic nuclei (AGN). The key idea of RM is to measure the time lag τ between variations in the continuum emission from the accretion disc and subsequent response of the bro ...