- Automatic detection of peculiar galaxies in large datasets of galaxy images
- Lior Shamir
We propose an image analysis unsupervised learning algorithm that can detect peculiar galaxies in datasets of galaxy images. The algorithm first computes a large set of calculated characteristics reflecting different aspects of the visual content, a …
- A Revised Parallel-sequence Morphological Classification of Galaxies: Structure and Formation of S0 and Spheroidal Galaxies
- Kormendy, John; Bender, Ralf
We update van den Bergh’s parallel-sequence galaxy classification in which S0 galaxies form a sequence S0a-S0b-S0c that parallels the sequence Sa-Sb-Sc of spiral galaxies. The ratio B/T of bulge-to-total light defines the position of a galaxy in thi …
- NEOWISE Studies of Asteroids with Sloan Photometry: Preliminary Results
- Mainzer, A.; Masiero, J.; Grav, T.; Bauer, J.; Tholen, D. J.; McMillan, R. S.; Wright, E.; Spahr, T.; Cutri, R. M.; Walker, R.; Mo, W.; Watkins, J.; Hand, E.; Maleszewski, C.
We have combined the NEOWISE and Sloan Digital Sky Survey data to study the albedos of 24,353 asteroids with candidate taxonomic classifications derived using Sloan photometry. We find a wide range of moderate to high albedos for candidate S-type as …
- Dependence of Barred Galaxy Fraction on Galaxy Properties and Environment
- Lee, Gwang-Ho; Park, Changbom; Lee, Myung Gyoon; Choi, Yun-Young
We investigate the dependence of the occurrence of bars in galaxies on galaxy properties and environment. We use a volume-limited sample of 33,391 galaxies brighter than Mr = -19.5 + 5logh at 0.02 <= z <= 0.05489, drawn from the Sloan Digital Sky Su …
- The Active Asteroids
- Jewitt, David
Some asteroids eject dust, unexpectedly producing transient, comet-like comae and tails. First ascribed to the sublimation of near-surface water ice, mass-losing asteroids (also called “main-belt comets”) can in fact be driven by a surprising divers …
- The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups
- Gerke, Brian F.; Newman, Jeffrey A.; Davis, Marc; Coil, Alison L.; Cooper, Michael C.; Dutton, Aaron A.; Faber, S. M.; Guhathakurta, Puragra; Konidaris, Nicholas; Koo, David C.; Lin, Lihwai; Noeske, Kai; Phillips, Andrew C.; Rosario, David J.; Weiner, Benjamin J.; Willmer, Christopher N. A.; Yan, Renbin
We present a public catalog of galaxy groups constructed from the spectroscopic sample of galaxies in the fourth data release from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) Galaxy Redshift Survey, including the Extended Groth Strip (EGS). …
- Exploring the Morphology of RAVE Stellar Spectra
- Matijevič, G.; Zwitter, T.; Bienaymé, O.; Bland-Hawthorn, J.; Boeche, C.; Freeman, K. C.; Gibson, B. K.; Gilmore, G.; Grebel, E. K.; Helmi, A.; Munari, U.; Navarro, J.; Parker, Q. A.; Reid, W.; Seabroke, G.; Siebert, A.; Siviero, A.; Steinmetz, M.; Watson, F. G.; Williams, M.; Wyse, R. F. G.
The RAdial Velocity Experiment (RAVE) is a medium-resolution (R ~ 7500) spectroscopic survey of the Milky Way that has already obtained over half a million stellar spectra. They present a randomly selected magnitude-limited sample, so it is importan …
- When time matters
- Pourbaix, D.
Whereas deriving the orbit of a binary star was perceived as a tedious task even during the second half of the 20th century, nowadays, computers can investigate millions of solutions and keep the best one in just a few seconds. However, even if one …
- Gravitational-Wave Data Analysis. Formalism and Sample Applications: The Gaussian Case
- Jaranowski, Piotr; Królak, Andrzej
The article reviews the statistical theory of signal detection in application to analysis of deterministic gravitational-wave signals in the noise of a detector. Statistical foundations for the theory of signal detection and parameter estimation are …
- Bayesian non-parametrics and the probabilistic approach to modelling
- Zoubin Ghahramani
Modelling is fundamental to many fields of science and engineering. A model can be thought of as a representation of possible data one could predict from a system. The probabilistic approach to modelling uses probability theory to express all aspect …
- Gaussian processes for time-series modelling
- S. Roberts, M. Osborne, M. Ebden, S. Reece, N. Gibson and S. Aigrain
In this paper, we offer a gentle introduction to Gaussian processes for time-series data analysis. The conceptual framework of Bayesian modelling for time-series data is discussed and the foundations of Bayesian non-parametric modelling presented fo …
- Independent component analysis: recent advances
- Aapo Hyvärinen
Independent component analysis is a probabilistic method for learning a linear transform of a random vector. The goal is to find components that are maximally independent and non-Gaussian (non-normal). Its fundamental difference to classical multi-v …
- Similarity and denoising
- Paul M. B. Vitányi
We can discover the effective similarity among pairs of finite objects and denoise a finite object using the Kolmogorov complexity of these objects. The drawback is that the Kolmogorov complexity is not computable. If we approximate it, using a good …
- Plain fundamentals of Fundamental Planes: analytics and algorithms
- Sheth, Ravi K.; Bernardi, Mariangela
Estimates of the coefficients a and b of the Fundamental Plane relation R∝σa Ib depend on whether one minimizes the scatter in the R direction, or orthogonal to the plane. We provide explicit expressions for a and b (and confidence limits) in ter …
- Computer Vision for the Solar Dynamics Observatory (SDO)
- Martens, P. C. H.; Attrill, G. D. R.; Davey, A. R.; Engell, A.; Farid, S.; Grigis, P. C.; Kasper, J.; Korreck, K.; Saar, S. H.; Savcheva, A.; Su, Y.; Testa, P.; Wills-Davey, M.; Bernasconi, P. N.; Raouafi, N.-E.; Delouille, V. A.; Hochedez, J. F.; Cirtain, J. W.; Deforest, C. E.; Angryk, R. A.; de Moortel, I.; Wiegelmann, T.; Georgoulis, M. K.; McAteer, R. T. J.; Timmons, R. P.
In Fall 2008 NASA selected a large international consortium to produce a comprehensive automated feature-recognition system for the Solar Dynamics Observatory (SDO). The SDO data that we consider are all of the Atmospheric Imaging Assembly (AIA) ima …
- A blind detection of a large, complex, Sunyaev-Zel’dovich structure
- AMI Consortium; Shimwell, T. W.; Barker, R. W.; Biddulph, P.; Bly, D.; Boysen, R. C.; Brown, A. R.; Brown, M. L.; Clementson, C.; Crofts, M.; Culverhouse, T. L.; Czeres, J.; Dace, R. J.; Davies, M. L.; D’Alessandro, R.; Doherty, P.; Duggan, K.; Ely, J. A.; Felvus, M.; Feroz, F.; Flynn, W.; Franzen, T. M. O.; Geisbüsch, J.; Génova-Santos, R.; Grainge, K. J. B.; Grainger, W. F.; Hammett, D.; Hobson, M. P.; Holler, C. M.; Hurley-Walker, N.; Jilley, R.; Kaneko, T.; Kneissl, R.; Lancaster, K.; Lasenby, A. N.; Marshall, P. J.; Newton, F.; Norris, O.; Northrop, I.; Odell, D. M.; Olamaie, M.; Perrott, Y. C.; Pober, J. C.; Pooley, G. G.; Pospieszalski, M. W.; Quy, V.; Rodríguez-Gonzálvez, C.; Saunders, R. D. E.; Scaife, A. M. M.; Schammel, M. P.; Schofield, J.; Scott, P. F.; Shaw, C.; Smith, H.; Titterington, D. J.; Velić, M.; Waldram, E. M.; West, S.; Wood, B. A.; Yassin, G.; Zwart, J. T. L.
We present an interesting Sunyaev-Zel’dovich (SZ) detection in the first of the Arcminute Microkelvin Imager (AMI) ‘blind’, degree-square fields to have been observed down to our target sensitivity of ?. In follow-up deep pointed observations …
- Parametrization effects in the analysis of AMI Sunyaev-Zel’dovich observations
- AMI Consortium; Olamaie, Malak; Rodríguez-Gonzálvez, Carmen; Davies, Matthew L.; Feroz, Farhan; Franzen, Thomas M. O.; Grainge, Keith J. B.; Hobson, Michael P.; Hurley-Walker, Natasha; Lasenby, Anthony N.; Pooley, Guy G.; Saunders, Richard D. E.; Scaife, Anna M. M.; Schammel, Michel; Scott, Paul F.; Shimwell, Timothy W.; Titterington, David J.; Waldram, Elizabeth M.; Zwart, Jonathan T. L.
Most Sunyaev-Zel’dovich (SZ) and X-ray analyses of galaxy clusters try to constrain the cluster total mass (MT(r)) and/or gas mass (Mg(r)) using parametrized models derived from both simulations and imaging observations, and assumptions of spherical …
- Principles of high-dimensional data visualization in astronomy
- Goodman, A. A.
Astronomical researchers often think of analysis and visualization as separate tasks. In the case of high-dimensional data sets, though, interactive exploratory data visualization can give far more insight than an approach where data processing and …
- Distinguishing between a true period and its alias, and other tasks of model discrimination
- Baluev, Roman V.
We consider the task of distinguishing between two different alternative models that can explain observed time-series data roughly equally, mainly focusing on the period-ambiguity case (aliasing). We propose a test for checking whether the rival mod …
- How well do STARLAB and NBODY compare? II. Hardware and accuracy
- Anders, P.; Baumgardt, H.; Gaburov, E.; Portegies Zwart, S.
Most recent progress in understanding the dynamical evolution of star clusters relies on direct N-body simulations. Owing to the computational demands, and the desire to model more complex and more massive star clusters, hardware calculational accel …