July – December 2014

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The first analytical expression to estimate photometric redshifts suggested by a machine
Krone-Martins, A.; Ishida, E. E. O.; de Souza, R. S.

We report the first analytical expression purely constructed by a machine to determine photometric redshifts (zphot) of galaxies. A simple and reliable functional form is derived using 41 214 galaxies from the Sloan Digital Sky Survey Data Release 1 …

SPINN: a straightforward machine learning solution to the pulsar candidate selection problem
Morello, V.; Barr, E. D.; Bailes, M.; Flynn, C. M.; Keane, E. F.; van Straten, W.

We describe SPINN (Straightforward Pulsar Identification using Neural Networks), a high-performance machine learning solution developed to process increasingly large data outputs from pulsar surveys. SPINN has been cross-validated on candidates from …

The Milky Way Project: Leveraging Citizen Science and Machine Learning to Detect Interstellar Bubbles
Beaumont, Christopher N.; Goodman, Alyssa A.; Kendrew, Sarah; Williams, Jonathan P.; Simpson, Robert

We present Brut, an algorithm to identify bubbles in infrared images of the Galactic midplane. Brut is based on the Random Forest algorithm, and uses bubbles identified by >35,000 citizen scientists from the Milky Way Project to discover the identif …

Estimating Luminosities and Stellar Masses of Galaxies Photometrically without Determining Redshifts
Hsieh, B. C.; Yee, H. K. C.

Large direct imaging surveys usually use a template-fitting technique to estimate photometric redshifts for galaxies, which are then applied to derive important galaxy properties such as luminosities and stellar masses. These estimates can be noisy …

Detection of a Faint Fast-moving Near-Earth Asteroid Using the Synthetic Tracking Technique
Zhai, Chengxing; Shao, Michael; Nemati, Bijan; Werne, Thomas; Zhou, Hanying; Turyshev, Slava G.; Sandhu, Jagmit; Hallinan, Gregg; Harding, Leon K.

We report a detection of a faint near-Earth asteroid (NEA) using our synthetic tracking technique and the CHIMERA instrument on the Palomar 200 inch telescope. With an apparent magnitude of 23 (H = 29, assuming detection at 20 lunar distances), the …

The distance to the Galactic center determined by OB stars
Branham, Richard L.

The OB stars are concentrated near the Galactic plane and should permit a determination of the distance to the Galactic center. van Leeuwen’s new reduction of the Hipparcos catalog provides, after 824 Gould belt stars have been excluded, 6288 OB s …

Data series subtraction with unknown and unmodeled background noise
Vitale, Stefano; Congedo, Giuseppe; Dolesi, Rita; Ferroni, Valerio; Hueller, Mauro; Vetrugno, Daniele; Weber, William Joseph; Audley, Heather; Danzmann, Karsten; Diepholz, Ingo; Hewitson, Martin; Korsakova, Natalia; Ferraioli, Luigi; Gibert, Ferran; Karnesis, Nikolaos; Nofrarias, Miquel; Inchauspe, Henri; Plagnol, Eric; Jennrich, Oliver; McNamara, Paul W.; Armano, Michele; Thorpe, James Ira; Wass, Peter

LISA Pathfinder (LPF), the precursor mission to a gravitational wave observatory of the European Space Agency, will measure the degree to which two test masses can be put into free fall, aiming to demonstrate a suppression of disturbance forces corr …

Method for all-sky searches of continuous gravitational wave signals using the frequency-Hough transform
Astone, Pia; Colla, Alberto; D’Antonio, Sabrina; Frasca, Sergio; Palomba, Cristiano

In this paper we present a hierarchical data analysis pipeline for all-sky searches of continuous gravitational wave signals, like those emitted by spinning neutron stars asymmetric with respect to the rotation axis, with unknown position, rotationa …

Voids in the SDSS DR9: observations, simulations, and the impact of the survey mask
Sutter, P. M.; Lavaux, Guilhem; Wandelt, Benjamin D.; Weinberg, David H.; Warren, Michael S.; Pisani, Alice

We present and study cosmic voids identified using the watershed void finder VIDE in the Sloan Digital Sky Survey Data Release 9, compare these voids to ones identified in mock catalogues, and assess the impact of the survey mask on void statistics …

Intercomparison of kinematics derived from catalogues UCAC4, PPMXL and XPM with vector spherical harmonics
Vityazev, V. V.; Tsvetkov, A. S.

We present the first application of the vector spherical harmonics technique to the proper motions of the catalogues UCAC4, XPM and PPMXL for stars in the 11 to 17 mag range. The results obtained from the all-sky and from the Northern and Southern G …

Data analysis pipeline for EChO end-to-end simulations
Waldmann, Ingo P.; Pascale, E.

Atmospheric spectroscopy of extrasolar planets is an intricate business. Atmospheric signatures typically require a photometric precision of 1×10-4 in flux over several hours. Such precision demands high instrument stability as well as an understan …

The Identification of Filaments on Far-infrared and Submillimiter Images: Morphology, Physical Conditions and Relation with Star Formation of Filamentary Structure
Schisano, E.; Rygl, K. L. J.; Molinari, S.; Busquet, G.; Elia, D.; Pestalozzi, M.; Polychroni, D.; Billot, N.; Carey, S.; Paladini, R.; Noriega-Crespo, A.; Moore, T. J. T.; Plume, R.; Glover, S. C. O.; Vázquez-Semadeni, E.

Observations of molecular clouds reveal a complex structure, with gas and dust often arranged in filamentary, rather than spherical geometries. The association of pre- and proto-stellar cores with the filaments suggests a direct link with the proces …

Rotational splitting as a function of mode frequency for six Sun-like stars
Nielsen, M. B.; Gizon, L.; Schunker, H.; Schou, J.

Asteroseismology offers the prospect of constraining differential rotation in Sun-like stars. Here we have identified six high signal-to-noise main-sequence Sun-like stars in the Kepler field, which all have visible signs of rotational splitting of …

A catalogue of photometric redshifts for the SDSS-DR9 galaxies
Brescia, M.; Cavuoti, S.; Longo, G.; De Stefano, V.

Context. Accurate photometric redshifts for large samples of galaxies are among the main products of modern multiband digital surveys. Over the last decade, the Sloan Digital Sky Survey (SDSS) has become a sort of benchmark against which to test the …

Searching transients in large-scale surveys. A method based on the Abbe value
Mowlavi, N.

Aims: A new method is presented to identify transient candidates in large-scale surveys based on the variability pattern in their light curves. Methods: The method is based on the Abbe value, Ab, that estimates the smoothness of a light curve, and …

Wavelets: a powerful tool for studying rotation, activity, and pulsation in Kepler and CoRoT stellar light curves
Bravo, J. P.; Roque, S.; Estrela, R.; Leão, I. C.; De Medeiros, J. R.

Aims: The wavelet transform has been used as a powerful tool for treating several problems in astrophysics. In this work, we show that the time-frequency analysis of stellar light curves using the wavelet transform is a practical tool for identifyin …

A new non-convex model of the binary asteroid 90 Antiope obtained with the SAGE modelling technique
Bartczak, P.; Michałowski, T.; Santana-Ros, T.; Dudziński, G.

We present a new non-convex model of the 90 Antiope binary asteroid, derived with a modified version of the Shaping Asteroids with Genetic Evolution (SAGE) method using disc-integrated photometry only. A new variant of the SAGE algorithm capable of …

Structure finding in cosmological simulations: the state of affairs
Knebe, Alexander; Pearce, Frazer R.; Lux, Hanni; Ascasibar, Yago; Behroozi, Peter; Casado, Javier; Moran, Christine Corbett; Diemand, Juerg; Dolag, Klaus; Dominguez-Tenreiro, Rosa; Elahi, Pascal; Falck, Bridget; Gottlöber, Stefan; Han, Jiaxin; Klypin, Anatoly; Lukić, Zarija; Maciejewski, Michal; McBride, Cameron K.; Merchán, Manuel E.; Muldrew, Stuart I.; Neyrinck, Mark; Onions, Julian; Planelles, Susana; Potter, Doug; Quilis, Vicent; Rasera, Yann; Ricker, Paul M.; Roy, Fabrice; Ruiz, Andrés N.; Sgró, Mario A.; Springel, Volker; Stadel, Joachim; Sutter, P. M.; Tweed, Dylan; Zemp, Marcel

The ever increasing size and complexity of data coming from simulations of cosmic structure formation demand equally sophisticated tools for their analysis. During the past decade, the art of object finding in these simulations has hence developed i …

A Posteriori Transit Probabilities
Stevens, Daniel J.; Gaudi, B. Scott

Given the radial velocity (RV) detection of an unseen companion, it is often of interest to estimate the probability that the companion also transits the primary star. Typically, one assumes a uniform distribution for the cosine of the inclination a …

Modeling Light Curves for Improved Classification
Julian Faraway, Ashish Mahabal, Jiayang Sun, Xiaofeng Wang, Yi (Grace) Wang, Lingsong Zhang

Many synoptic surveys are observing large parts of the sky multiple times. The resulting lightcurves provide a wonderful window to the dynamic nature of the universe. However, there are many significant challenges in analyzing these light curves. Th …