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Related papers: Beyond Stacking: A Maximum-Likelihood Method to Co…

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We propose a machine-learning-based technique to determine the number density of radio sources as a function of their flux density, for use in next-generation radio surveys. The method uses a convolutional neural network trained on…

Instrumentation and Methods for Astrophysics · Physics 2024-01-17 Elisa Todarello , Andre Scaffidi , Marco Regis , Marco Taoso

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…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Ian Heywood , Matt J. Jarvis , James J. Condon

Measuring radio source counts is critical for characterizing new extragalactic populations, brings a wealth of science within reach and will inform forecasts for SKA and its pathfinders. Yet there is currently great debate (and few…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-09 Jonathan T. L. Zwart , Mario Santos , Matt J. Jarvis

We have developed a maximum likelihood source detection method capable of detecting ultra-faint streaks with surface brightnesses approximately an order of magnitude fainter than the pixel level noise. Our maximum likelihood detection…

Instrumentation and Methods for Astrophysics · Physics 2016-09-26 William A. Dawson , Michael D. Schneider , Chandrika Kamath

In this paper, we consider a novel and robust maximum likelihood approach to localizing radiation sources with unknown statistics of the source signal strength. The result utilizes the smallest number of sensors required theoretically to…

Optimization and Control · Mathematics 2016-10-11 Henry E. Baidoo-Williams

We describe the application of a statistical method to estimate submillimeter galaxy number counts from confusion limited observations by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST). Our method is based on a maximum…

We present a method of reliably extracting the flux of individual sources from sky maps in the presence of noise and a source population in which number counts are a steeply falling function of flux. The method is an extension of a standard…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 T. M. Crawford , E. R. Switzer , W. L. Holzapfel , C. L. Reichardt , D. P. Marrone , J. D. Vieira

The use of continuum emission radio galaxies as cosmological tracers of the large-scale structure will soon move into a new phase. Upcoming surveys from the Australian Square Kilometre Array Pathfinder (ASKAP), MeerKAT, and the Square…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-28 Jacobo Asorey , David Parkinson

We present stacking polarized intensity as a means to study the polarization of sources that are too faint to be detected individually in surveys of polarized radio sources. Stacking offers not only high sensitivity to the median signal of…

Astrophysics of Galaxies · Physics 2015-06-19 J. M. Stil , B. W. Keller , S. J. George , A. R. Taylor

We explore the use of different radio galaxy populations as tracers of different mass halos and therefore, with different bias properties, to constrain primordial non-Gaussianity of the local type. We perform a Fisher matrix analysis based…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Luis D. Ferramacho , Mario G. Santos , Matt J. Jarvis , Stefano Camera

We present a new method for determining the sensitivity of X-ray imaging observations, which correctly accounts for the observational biases that affect the probability of detecting a source of a given X-ray flux, without the need to…

Astrophysics · Physics 2009-11-13 A. Georgakakis , K. Nandra , E. S. Laird , J. Aird , M. Trichas

This paper extends the method introduced in Rivi et al. (2016b) to measure galaxy ellipticities in the visibility domain for radio weak lensing surveys. In that paper we focused on the development and testing of the method for the simple…

Instrumentation and Methods for Astrophysics · Physics 2018-04-16 Marzia Rivi , Lance Miller

An international project is underway to design and build a radio telescope with an effective collecting area two orders of magnitude greater than the largest existing instruments. One of the many scientific goals of this instrument will be…

Astrophysics · Physics 2009-09-25 A. Hopkins , R. Windhorst , L. Cram , R. Ekers

The ALMACAL project leverages ALMA maps of calibrator-centered fields to conduct deep mm/sub-mm surveys, enabling the detection of extragalactic sources with flux densities orders of magnitude fainter than achievable with other instruments.…

Extragalactic radio sources are a unique cosmological probe in that they trace large-scale structure on scales inaccessible to other wavelengths. However as radio survey data is inherently 2D, the redshift distribution, N(z), is necessary…

Astrophysics · Physics 2007-05-23 C A Jackson , J V Wall

Image coaddition is one of the most basic operations that astronomers perform. In Paper~I, we presented the optimal ways to coadd images in order to detect faint sources and to perfrom flux measurements under the assumption that the noise…

Instrumentation and Methods for Astrophysics · Physics 2018-03-28 Barak Zackay , Eran O. Ofek

(Abridged) We present a new method for detecting and measuring compact sources in conditions of intense, and highly variable, fore/background. While all most commonly used packages carry out the source detection over the signal image, our…

We describe an X-ray source detection method entirely based on the maximum likelihood analysis, in application to observations with the ART-XC telescope onboard the Spectrum Roentgen Gamma observatory. The method optimally combines the data…

High Energy Astrophysical Phenomena · Physics 2024-04-03 A. Semena , A. Vikhlinin , I. Mereminskiy , A. Lutovinov , A. Tkachenko , I. Lapshov , R. Burenin

The FIRST survey, begun over twenty years ago, provides the definitive high-resolution map of the radio sky. This VLA survey reaches a 20cm detection sensitivity of 1 mJy over 10,575 deg**2 largely coincident with the SDSS area. Images and…

Astrophysics of Galaxies · Physics 2015-06-23 David J. Helfand , Richard L. White , Robert H. Becker

Detection of point sources in images is a fundamental operation in astrophysics, and is crucial for constraining population models of the underlying point sources or characterizing the background emission. Standard techniques fall short in…

Instrumentation and Methods for Astrophysics · Physics 2018-02-28 Tansu Daylan , Stephen K. N. Portillo , Douglas P. Finkbeiner
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