J/A+A/631/A148 PSZ2 cluster candidates. II. (Aguado-Barahona+, 2019)
Optical validation and characterization of Planck PSZ2 sources at the Canary
Islands observatories. II. Second year of LP15 observations.
Aguado-Barahona A., Barrena R., Streblyanska A., Ferragamo A.,
Rubino-Martin J.A., Tramonte D., Lietzen H.
<Astron. Astrophys., 631, A148 (2019)>
=2019A&A...631A.148A 2019A&A...631A.148A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Redshifts ; Radio sources
Keywords: galaxies: clusters: general - large-scale structure of Universe -
catalogs
Abstract:
The second legacy catalog of Planck Sunyaev-Zeldovich (SZ)
sources, hereafter PSZ2, provides the largest galaxy cluster sample
selected by means of the SZ signature of the clusters in a full sky
survey. In order to fully characterize this PSZ2 sample for
cosmological studies, all the members should be validated and the
physical properties of the clusters, including mass and redshift,
should be derived. However, at the time of its publication, roughly
21% of the 1653 PSZ2 members had no known counterpart at other
wavelengths.
Here, we present the second and last year of observations of our
optical follow-up program 128-MULTIPLE-16/15B (hereafter LP15), which
has been developed with the aim of validating all the unidentified
PSZ2 sources in the northern sky with declinations higher than
-15° that have no correspondence in the first Planck catalog PSZ1.
The description of the program and the first year of observations have
been presented previously.
The LP15 program was awarded 44 observing nights that were spread over
two years with the Isaac Newton Telescope (INT), the Telescopio
Nazionale Galileo (TNG), and the Gran Telescopio Canarias (GTC), all
at Roque de los Muchachos Observatory (La Palma). Following the same
method as described previously, we performed deep optical imaging for
more than 200 sources with the INT and spectroscopy for almost 100
sources with the TNG and GTC at the end of the LP15 program. We
adopted robust confirmation criteria based on velocity dispersion and
richness estimates for the final classification of the new galaxy
clusters as the optical counterparts of the PSZ2 detections.
Here, we present the observations of the second year of LP15, as well
as the final results of the program. The full LP15 sample comprises
190 previously unidentified PSZ2 sources. Of these, 106 objects were
studied before, while the remaining sample (except for 6 candidates)
has been completed in the second year and is discussed here. In
addition to the LP15 sample, we here study 42 additional PSZ2 objects
that were originally validated as real clusters because they matched a
WISE or PSZ1 counterpart, but they had no measured spectroscopic
redshift. In total, we confirm the optical counterparts for 81 PSZ2
sources after the full LP15 program, 55 of them with new spectroscopic
information. Forty of these 81 clusters are presented in this paper.
After the LP15 observational program the purity of the PSZ2 catalog
has increased from 76.7% originally to 86.2%. In addition, we study
the possible reasons for false detection, and we report a clear
correlation between the number of unconfirmed sources and galactic
thermal dust emission.
Description:
During the second year of observations, 78 PSZ2 sources with no known
optical counterpart have been observed. A robust confirmation
criterion based on velocity dispersion, when available, and richness
estimations enabled us to confirm 40 candidates, for which we provided
18 spectroscopic and 22 photometric redshifts.
We updated the information on 42 sources that have been validated in
the original PSZ2 catalog but lacked a redshift estimate. We provided
a spectroscopic redshift for 20 of them and a photometric redshift for
20 sources. We also studied the richness and applied the same criteria
as for the candidates in order to check the associations with the SZ
signal. We discovered that three previously confirmed counterparts
were not present in the optical range studied here.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 178 80 78 PSZ2 cluster candidates
tablea2.dat 140 42 Updated information of other PSZ2 candidates
beyond the LP15 sample
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See also:
J/A+A/594/A27 : Planck Sunyaev-Zeldovich sources (PSZ2) (Planck+, 2016)
J/A+A/628/A13 : PSZ2 cluster candidates. I. (Streblyanska+, 2019)
Byte-by-byte Description of file: tablea1.dat tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
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1- 4 I4 --- ID Official identification number
5 A1 --- --- [-]
6 A1 --- m_ID [AB] Multiplicity index on ID for
multiple counterparts
8- 12 A5 --- n_ID Notes on ID (1)
14- 31 A18 --- PSZ2 PSZ2 designation, PSZ2 GLLL.ll+BB.bb
33- 36 F4.2 --- S/N ? SZ signal-to-noise ratio
38- 39 I2 h RAh ? BGC Right ascension (J2000)
41- 42 I2 min RAm ? BGC Right ascension (J2000)
44- 49 F6.3 s RAs ? BGC Right ascension (J2000)
50 A1 --- DE- BGC Declination sign (J2000)
51- 52 I2 deg DEd ? BGC Declination (J2000)
54- 55 I2 arcmin DEm ? BGC Declination (J2000)
57- 61 F5.2 arcsec DEs ? BGC Declination (J2000)
63- 67 F5.2 arcmin Dist ? Distance between Planck and the optical
center reported in this work
69- 73 F5.3 --- zsp ? Mean spectroscopic redshift of the cluster
75 A1 --- --- [;]
77- 82 F6.4 --- zsp2 ? BCG spectroscopic redshift
85- 86 I2 --- nsp ? Number of spectroscopic members retrieved
88- 91 F4.2 --- zph ? Photometric redshift
93- 96 F4.2 --- e_zph ? Photometric redshift error
98-101 F4.1 --- Rcor ? Richness estimate
103-105 F3.1 --- e_Rcor ? Richness estimate error
107-110 F4.1 --- sigmaR ? Background level
112-113 A2 --- Flag Flag (2)
115-178 A64 --- Notes Notes (3)
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Note (1): Notes as follows:
b = Photometric and/or spectroscopic redshift obtained from SDSS DR14 data
c = Previously confirmed in Streblyanska et al. (2018A&A...617A..71S 2018A&A...617A..71S)
d = Classified as "potentially associated" in Streblyanska et al.
(2018A&A...617A..71S 2018A&A...617A..71S)
e = Richness study from PAN-STARRS
f = No imaging performed, private communication with the Saclay group
Note (2): Flags as follows:
1 = validated cluster
(Spectrosocopy: Yes, σv>500km/s (z<0.2) σR>1.5)
2 = validated cluster
(Spectrosocopy: No , σv>650km/s (z>0.2) σR>1.5)
3 = candidate cluster
ND = SZ candidates without a galaxy overdensity in the optical images
Note (3): References as follows:
(1) = Burenin (2017AstL...43..507B 2017AstL...43..507B, Cat. J/PAZh/43/559),
(2) = Rykoff et al. (2014ApJ...785..104R 2014ApJ...785..104R, Cat. J/ApJ/785/104)
(3) = Burenin et al. (2018AstL...44...297B)
(4) = Zaznobin et al. (2019AstL...45...49Z 2019AstL...45...49Z)
(5) = Boada et al. (2019ApJ...871..188B 2019ApJ...871..188B)
(11) = De Propris et al. (2002MNRAS.329...87D 2002MNRAS.329...87D, Cat. J/MNRAS/329/87)
(12) = Amodeo et al. (2018ApJ...853...36A 2018ApJ...853...36A, Cat. J/ApJ/853/36)
(13) = Buddendiek et al. (2015MNRAS.450.4248B 2015MNRAS.450.4248B)
(14) = Burenin et al. (2018AstL...44...297B)
(15) = Streblyanska et al. (2018A&A...617A..71S 2018A&A...617A..71S)
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History:
From electronic version of the journal
References:
Streblyanska et al., Paper I 2019A&A...628A..13S 2019A&A...628A..13S, Cat. J/A+A/628/A13
(End) Patricia Vannier [CDS] 19-Feb-2020