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相关论文: The miniJPAS survey quasar selection I: Mock catal…

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The shape of the curves defined by the counts of radio sources per unit area as a function of their flux density was one of the earliest cosmological probes. Radio source counts continue to be an area of interest, used to study the relative…

宇宙学与河外天体物理 · 物理学 2015-06-15 Ian Heywood , Matt J. Jarvis , James J. Condon

The aim of this paper is twofold: In the first part, we leverage recent results on scenario design to develop randomized algorithmsfor approximating the image set of a nonlinear mapping, that is, a (possibly noisy) mapping of a set via a…

最优化与控制 · 数学 2015-07-30 Fabrizio Dabbene , Didier Henrion , Constantino Lagoa , Pavel Shcherbakov

We present the discovery of 3 quasar lenses in the Sloan Digital Sky Survey (SDSS), selected using two novel photometry-based selection techniques. The J0941+0518 system, with two point sources separated by 5.46" on either side of a galaxy,…

We present a statistical method based on a maximum likelihood approach to constrain the number counts of extragalactic sources below the nominal flux-density limit of continuum imaging surveys. We extract flux densities from a radio map…

天体物理仪器与方法 · 物理学 2015-06-16 Ketron Mitchell-Wynne , Mario G. Santos , Jose Afonso , Matt J. Jarvis

Machine learning can provide powerful tools to detect patterns in multi-dimensional parameter space. We use K-means -a simple yet powerful unsupervised clustering algorithm which picks out structure in unlabeled data- to study a sample of…

星系天体物理 · 物理学 2016-03-11 Aycha Tammour , Sarah C. Gallagher , Mark Daley , Gordon T. Richards

We consider the statistical problem of catalogue matching from a machine learning perspective with the goal of producing probabilistic outputs, and using all available information. A framework is provided that unifies two existing…

天体物理学 · 物理学 2009-11-11 D. J. Rohde , M. R. Gallagher , M. J. Drinkwater , K. A. Pimbblet

The angular power spectrum is a powerful statistic for analysing cosmological signals imprinted in the clustering of matter. However, current galaxy and quasar surveys cover limited portions of the sky, and are contaminated by systematics…

宇宙学与河外天体物理 · 物理学 2013-10-29 Boris Leistedt , Hiranya V. Peiris , Daniel J. Mortlock , Aurélien Benoit-Lévy , Andrew Pontzen

The impending Javalambre Physics of the accelerating universe Astrophysical Survey (J-PAS) will be the first wide-field survey of $\gtrsim$ 8500 deg$^2$ to reach the `stage IV' category. Because of the redshift resolution afforded by 54…

We propose a machine learning approach to the blind detection of extragalactic point sources on maps of the temperature anisotropies of the cosmic microwave background. Using realistic simulations of the microwave sky as seen by Planck, we…

宇宙学与河外天体物理 · 物理学 2023-03-01 P. Diego-Palazuelos , R. B. Barreiro , P. Vielva , D. Balbás , M. López-Caniego , D. Herranz , B. Casaponsa

Weak gravitational lensing is a powerful probe of the large-scale cosmic matter distribution. Wide-field galaxy surveys allow us to generate the so-called weak lensing maps, but actual observations suffer from noise due to imperfect…

宇宙学与河外天体物理 · 物理学 2019-08-21 Masato Shirasaki , Naoki Yoshida , Shiro Ikeda

Various galaxy merger detection methods have been applied to diverse datasets. However, it is difficult to understand how they compare. We aim to benchmark the relative performance of machine learning (ML) merger detection methods. We…

We describe a method for deriving the position and flux of point and compact sources observed by a scanning survey mission. Results from data simulated to test our method are presented, which demonstrate that at least a 10-fold improvement…

天体物理仪器与方法 · 物理学 2015-05-13 F. van Leeuwen , A. N. Morgan , D. L. Harrison

In this paper we introduce a new linear filtering technique, the so-called matrix filters, that maximizes the signal-to-interference ratio of compact sources of unknown intensity embedded in a set of images by taking into account the…

天体物理学 · 物理学 2009-11-13 D. Herranz , J. L. Sanz

We have used the KPNO 4-meter Mayall telescope to image 0.83 square degrees of sky in six fields at high galactic latitude in six filters spanning 3000-10000\AA\ to magnitude limits ranging from 22.1 to 23.8. As a first use of this…

天体物理学 · 物理学 2009-10-28 Patrick B. Hall , Patrick S. Osmer , Richard F. Green , Alain C. Porter , Stephen J. Warren

Weak lensing experiments are a powerful probe of cosmology through their measurement of the mass distribution of the universe. A challenge for this technique is to control systematic errors that occur when measuring the shapes of distant…

宇宙学与河外天体物理 · 物理学 2015-06-04 Alexandre Refregier , Tomasz Kacprzak , Adam Amara , Sarah Bridle , Barnaby Rowe

We present a comparison of major methodologies of fast generating mock halo or galaxy catalogues. The comparison is done for two-point and the three-point clustering statistics. The reference catalogues are drawn from the BigMultiDark…

The two currently largest all-sky photometric datasets, WISE and SuperCOSMOS, were cross-matched by Bilicki et al. (2016) (B16) to construct a novel photometric redshift catalogue on 70% of the sky. Galaxies were therein separated from…

星系天体物理 · 物理学 2016-11-30 T. Krakowski , K. Małek , M. Bilicki , A. Pollo , M. Krupa , A. Kurcz

The efficient classification of different types of supernova is one of the most important problems for observational cosmology. However, spectroscopic confirmation of most objects in upcoming photometric surveys, such as the The Rubin…

宇宙学与河外天体物理 · 物理学 2020-08-17 Marcelo Vargas dos Santos , Miguel Quartin , Ribamar R. R. Reis

We study the accuracy with which weak lensing measurements could be made from a future space-based survey, predicting the subsequent precisions of 3-dimensional dark matter maps, projected 2-dimensional dark matter maps, and mass-selected…