J/ApJ/753/27 New point sources in the WMAP 7yr data (Scodeller+, 2012)
Detection of new point sources in WMAP 7 year data using internal templates and
needlets.
Scodeller S., Hansen F.K., Marinucci D.
<Astrophys. J., 753, 27 (2012)>
=2012ApJ...753...27S 2012ApJ...753...27S
ADC_Keywords: Galaxies, radio ; Cross identifications ; Radio continuum ;
Surveys ; Interstellar medium
Keywords: cosmic background radiation; cosmology: observations;
methods: data analysis; methods: statistical
Abstract:
We have developed a new needlet-based method to detect point sources
in cosmic microwave background (CMB) maps and have applied it to the
Wilkinson Microwave Anisotropy Probe (WMAP) 7 year data. We use both
the individual frequency channels as well as internal templates, the
latter being the difference between pairs of frequency channels and
hence having the advantage that the CMB component is eliminated. Using
the area of the sky outside the Kq85 galactic mask, we detect a total
of 2102 point sources at the 5σ level in either the frequency
maps or the internal templates. Of these, 1116 are detected either at
5σ directly in the frequency channels or at 5σ in the
internal templates and ≥3σ at the corresponding position in
the frequency channels. Of the 1116 sources, 603 are detections that
have not been reported so far in WMAP data. We have made a catalog of
these sources available with position and flux estimated in the WMAP
channels where they are seen. In total, we identified 1029 of the 1116
sources with counterparts at 5GHz and 69 at other frequencies.
Description:
Here, we present a method for the point-source detection in the WMAP 7
year data, that is novel in two ways: (1) it uses the family of
standard (Marinucci et al. 2008MNRAS.383..539M 2008MNRAS.383..539M) and Mexican (Scodeller
et al. 2011ApJ...733..121S 2011ApJ...733..121S) needlets optimized for point-source
detection on the given channels, and (2) we search for point sources
both in the individual WMAP channels and in the CMB-free internal
templates (Hansen et al. 2006ApJ...648..784H 2006ApJ...648..784H) constructed from the
difference between two frequency channels.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 122 1116 New point sources in WMAP
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See also:
VIII/88 : Planck Early Release Compact Source Catalogue (Planck, 2011)
VIII/81 : Sydney University Molonglo Sky Survey (SUMSS V2.1) (Mauch+ 2008)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/40 : GB6 catalog of radio sources (Gregory+ 1996)
VIII/38 : The Parkes-MIT-NRAO 4.85GHz (PMN) Surveys (Griffith+ 1993-1996)
VIII/5 : Bright Extragalactic Radio Sources (1Jy) (Kuehr+, 1981)
J/ApJS/208/20 : Nine-year WMAP point source catalogs (Bennett+, 2013)
J/MNRAS/428/3048 : WMAP point sources at 61 and 94GHz (Lanz+, 2013)
J/ApJS/192/15 : Seven-year WMAP catalog (Gold+, 2011)
J/MNRAS/400/995 : WMAP 3-yr sources at 16 and 33GHz. II. (Franzen+, 2009)
J/MNRAS/392/733 : The NEWPS catalog from WMAP 5-yr survey (Massardi+, 2009)
J/ApJ/694/222 : Extragalactic point sources in WMAP 5-yr maps (Chen+, 2009)
J/MNRAS/400/984 : WMAP 3-yr sources at 16 and 33GHz (Davies+, 2009)
J/AZh/85/483 : Sources from the WMAP catalog (Vol'vach+, 2008)
J/ApJ/681/747 : Extragalactic point-source WMAP catalog (Chen+, 2008)
J/ApJS/170/108 : NEWPS5σ source cat. from WMAP (Lopez-Caniego+, 2007)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq Running sequence number
6- 12 F7.3 deg RAdeg Right Ascension in decimal degrees (J2000) (1)
14- 20 F7.3 deg DEdeg Declination in decimal degrees (J2000) (1)
22- 26 F5.2 Jy FK [0.1/24]? WMAP K band (23GHz) flux density (2)
28- 31 F4.2 Jy e_FK [0.04/0.3]? Uncertainty in FK
33 A1 --- f_FK [i] very weak FK (3)
35- 39 F5.2 Jy FKa [0.1/22]? WMAP Ka band (30GHz) flux density (2)
41- 44 F4.2 Jy e_FKa ? Uncertainty in FKa
46 A1 --- f_FKa [i] very weak FKa (3)
48- 52 F5.2 Jy FQ [0.1/20]? WMAP Q band (41GHz) flux density (2)
54- 57 F4.2 Jy e_FQ ? Uncertainty in FQ
59 A1 --- f_FQ [i] very weak FQ (3)
61- 65 F5.2 Jy FV [0.1/18]? WMAP V band (61GHz) flux density (2)
67- 70 F4.2 Jy e_FV ? Uncertainty in FV
72 A1 --- f_FV [i] very weak FV (3)
74- 78 F5.2 Jy FW [0.2/15]? WMAP W band (94GHz) flux density (2)
80- 83 F4.2 Jy e_FW ? Uncertainty in FW
85 A1 --- f_FW [i] very weak FW (3)
87- 91 A5 --- Fflag The 5σ detection flag (4)
93- 95 A3 --- Cflag Catalog flag (5)
97-115 A19 --- Cat-ID Source identification (6)
117-120 F4.1 arcmin Off [0.1/15]? Offset from the Cat-ID position
121-122 A2 --- f_Off [MA] Multiple of weak source (7)
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Note (1): Given by the weighted average of the positions in all frequencies
where the source is found.
Note (2): For converting the source temperature and errors from Kelvin to
Jansky we use the effective beam area and relative error as presented
in table 4 of Jarosik et al. (2011ApJS..192...14J 2011ApJS..192...14J).
Note (3):
i = A very weak source where we are unable to correct the flux for
Eddington bias due to the low signal-to-noise level (see section 4.3).
We use the internal template detection to estimate the unbiased flux in
the given channel as explained in section 4.3.
Note (4): One flag for each band that indicates whether we detected the
source at 5σ in the individual channel ("C"), or in the template
with a 3σ detection in the channel ("F") or not at all (".").
Note (5): Flags indicating if the found source is identified in a given
catalog in at least one frequency:
W = WMAP-catalogs (Gold et al. 2011, Cat. J/ApJS/192/15);
N = NEWPS 5yr 5s-catalog (Massardi et al. 2009, Cat. J/MNRAS/392/733);
P = ERCSC-catalogs (at 30,44,70,100 GHz only; Planck Collaboration 2011,
Cat. VIII/88).
Note (6): Identification with the GB6 (Gregory et al. 1996, Cat. VIII/40),
PMN (Griffith et al. 1993-1996, Cat. VIII/38);
1Jy (Kuehr et al. 1981, Cat. VIII/5) when possible or with the lower
frequency catalogs NVSS (Condon et al. 1998, Cat. VIII/65) and SUMSS
(Mauch et al. 2003, Cat. VIII/81) catalog counterparts.
Note (7): A flag of "M" is used if there are multiple identifications possible
(where we took the brightest one) and a flag "A" if the listed
counterpart has a flux density below 100 mJy.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 10-Feb-2014