2017A&A...604A.115V


Query : 2017A&A...604A.115V

2017A&A...604A.115V - Astronomy and Astrophysics, volume 604A, 115-115 (2017/8-1)

The correct estimate of the probability of false detection of the matched filter in weak-signal detection problems. II. Further results with application to a set of ALMA and ATCA data.

VIO R., VERGES C. and ANDREANI P.

Abstract (from CDS):

The matched filter (MF) is one of the most popular and reliable techniques to the detect signals of known structure and amplitude smaller than the level of the contaminating noise. Under the assumption of stationary Gaussian noise, MF maximizes the probability of detection subject to a constant probability of false detection or false alarm (PFA). This property relies upon a priori knowledge of the position of the searched signals, which is usually not available. Recently, it has been shown that when applied in its standard form, MF may severely underestimate the PFA. As a consequence the statistical significance of features that belong to noise is overestimated and the resulting detections are actually spurious. For this reason, an alternative method of computing the PFA has been proposed that is based on the probability density function (PDF) of the peaks of an isotropic Gaussian random field. In this paper we further develop this method. In particular, we discuss the statistical meaning of the PFA and show that, although useful as a preliminary step in a detection procedure, it is not able to quantify the actual reliability of a specific detection. For this reason, a new quantity is introduced called the specific probability of false alarm (SPFA), which is able to carry out this computation. We show how this method works in targeted simulations and apply it to a few interferometric maps taken with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Australia Telescope Compact Array (ATCA). We select a few potential new point sources and assign an accurate detection reliability to these sources.

Abstract Copyright: © ESO, 2017

Journal keyword(s): methods: data analysis - methods: statistical - methods: numerical - methods: numerical

Nomenclature: Table 1: [VVA2017] Na (Nos 1a-1b, 2a-2d, 3a-3c).

CDS comments: USNO-B1.0 0707-10151219 is a misprint for USNO-B1.0 0707-00151219.

Simbad objects: 7

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Number of rows : 7
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 SSTSL2 J051230.46-682802.0 IR 05 12 30.46 -68 28 02.0           ~ 1 0
2 SUMSS J051432-685446 Rad 05 14 32.630 -68 54 46.80           ~ 1 0
3 SSTSL2 J051555.19-690746.2 IR 05 15 55.19 -69 07 46.2           ~ 1 0
4 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 16522 1
5 2MASX J07473002-1917503 IR 07 47 30.026 -19 17 50.34           ~ 2 0
6 USNO-B1.0 0707-00151219 * 07 47 30.6354803784 -19 17 18.292543080   20.5   19.8   ~ 1 0
7 2MASX J07473129-1917403 BiC 07 47 31.3247085936 -19 17 40.013334276   19.60       ~ 403 1

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2023.02.02-18:32:56

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