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In this study, a multiple-comparison approach is developed for detecting faint hyperspectral sources. The detection method relies on a sparse and non-negative representation on a highly coherent dictionary to track a spatially varying…

Methodology · Statistics 2017-05-24 Raphael Bacher , Celine Meillier , Florent Chatelain , Olivier Michel

(abridged) Hard X-ray surveys performed by the INTEGRAL satellite have discovered a conspicuous fraction (up to 30%) of unidentified objects among the detected sources. Here we continue our identification program by selecting probable…

X-ray sources with very few counts can be identified with low-noise X-ray detectors such as ACIS onboard the Chandra X-ray Observatory. These sources are often too faint for parametric spectral modeling using well-established methods such…

Solar and Stellar Astrophysics · Physics 2014-11-20 Konstantin V. Getman , Eric D. Feigelson , Patrick S. Broos , Leisa K. Townsley , Gordon P. Garmire

We have developed a general data reduction technique for ISOCAM data coming from various deep surveys of faint galaxies. In order to reach the fundamental limits of the camera (due to the background photon noise and the readout noise), we…

We present a 3-dimensional matched filtering approach for the blind search of faint emission-line sources in integral-field spectroscopic datasets. The filter is designed to account for the spectrally rapidly varying background noise due to…

Instrumentation and Methods for Astrophysics · Physics 2023-03-21 Edmund Christian Herenz

Procedures based on current methods to detect sources in X-ray images are applied to simulated XMM images. All significant instrumental effects are taken into account, and two kinds of sources are considered -- unresolved sources…

Astrophysics · Physics 2009-11-06 I. Valtchanov , M. Pierre , R. Gastaud

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

Thanks to the INTEGRAL satellite the way of looking at the hard X-ray sky above 20 keV has changed substantially. Through the unique imaging and spectroscopy capabilities of the IBIS instrument that has formed the basis of the INTEGRAL…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 P. Parisi , N. Masetti

Abridged : The various IBIS/ISGRI catalogues contain a large population of hard X-ray sources whose nature is still unknown. Even if the $>20$ keV positional uncertainty provided by ISGRI is unprecedented, it is still too large to pinpoint…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Jerome Rodriguez , John A. Tomsick , Arash Bodaghee

Observational astronomy in the time-domain era faces several new challenges. One of them is the efficient use of observations obtained at multiple epochs. The work presented here addresses faint object detection with multi-epoch data, and…

Instrumentation and Methods for Astrophysics · Physics 2017-04-19 Tamas Budavari , Alexander S. Szalay , Thomas J. Loredo

Current synoptic sky surveys monitor large areas of the sky to find variable and transient astronomical sources. As the number of detections per night at a single telescope easily exceeds several thousand, current detection pipelines make…

We describe the method used to detect sources for the Herschel-ATLAS survey. The method is to filter the individual bands using a matched filter, based on the point-spread function (PSF) and confusion noise, and then form the inverse…

Instrumentation and Methods for Astrophysics · Physics 2020-02-26 S. J. Maddox , L. Dunne

Since its launch on October 2002, the INTEGRAL satellite has revolutionized our knowledge of the hard X-ray sky thanks to its unprecedented imaging capabilities and source detection positional accuracy above 20 keV. Nevertheless, many of…

(Abridged) Since its launch in October 2002, the INTEGRAL satellite has revolutionized our knowledge of the hard X-ray sky thanks to its unprecedented imaging capabilities and source detection positional accuracy above 20 keV. Nevertheless,…

Context: In 6 years of operation, INTEGRAL/ISGRI revealed more than 500 sources. Many of these sources are variable. Taking into account that nearly half of INTEGRAL/ISGRI sources are new and many of them are still unidentified, the…

High Energy Astrophysical Phenomena · Physics 2015-05-18 I. Telezhinsky , D. Eckert , V. Savchenko , A. Neronov , N. Produit , T. J. -L. Courvoisier

Our present knowledge of the properties of blazars mostly comes from small samples of bright objects, especially regarding studies on their cosmological evolution. Statistically well defined and completely identified samples of faint…

High Energy Astrophysical Phenomena · Physics 2019-09-04 Sara Turriziani , Bernardo Fraga , Paolo Giommi

We present a new detection algorithm based on the wavelet transform for the analysis of high energy astronomical images. The wavelet transform, due to its multi-scale structure, is suited for the optimal detection of point-like as well as…

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 second IBIS/ISGRI survey has produced a catalogue containing 209 hard X-ray sources visible down to a flux limit of around 1 milliCrab. The point source location accuracy of typically 1-3 arcminutes has allowed the counterparts for most…

Upcoming next-generation sky surveys will detect large number of faint objects with magnitudes larger than 25. When objects are crowded within a limited a field of view, blending becomes unavoidable. Blending leads to the omission of many…

Instrumentation and Methods for Astrophysics · Physics 2026-03-03 Yibo Yan , Chao Liu , Jiadong Li , Feng Wang
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