J/MNRAS/455/1796 IDEOS redshift catalogue (Hernan-Caballero+, 2016)
The infrared database of extragalactic observables from Spitzer.
I. The redshift catalogue.
Hernan-Caballero A., Spoon H.W.W., Lebouteiller V., Rupke D.S.N.,
Barry D.P.
<Mon. Not. R. Astron. Soc., 455, 1796-1806 (2016)>
=2016MNRAS.455.1796H 2016MNRAS.455.1796H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; Redshifts
Keywords: methods: data analysis - catalogues -
galaxies: distances and redshifts - infrared: galaxies
Abstract:
This is the first of a series of papers on the Infrared Database of
Extragalactic Observables from Spitzer (IDEOS). In this work, we
describe the identification of optical counterparts of the infrared
sources detected in Spitzer Infrared Spectrograph (IRS) observations
and the acquisition and validation of redshifts. The IDEOS sample
includes all the spectra from the Cornell Atlas of Spitzer/IRS Sources
(CASSIS, Lebouteiller et al., 2011ApJS..196....8L 2011ApJS..196....8L,
2015ApJS..218...21L 2015ApJS..218...21L) of galaxies beyond the Local Group. Optical
counterparts were identified from correlation of the extraction
coordinates with the NASA Extragalactic Database (NED). To confirm the
optical association and validate NED redshifts, we measure redshifts
with unprecedented accuracy on the IRS spectra
(σ(Δz/(1+z))∼0.0011) by using an improved version of the
maximum combined pseudo-likelihood method (MCPL). We perform a
multistage verification of redshifts that considers alternate NED
redshifts, the MCPL redshift, and visual inspection of the IRS
spectrum. The statistics is as follows: the IDEOS sample contains 3361
galaxies at redshift 0<z<6.42 (mean: 0.48, median: 0.14). We confirm
the default NED redshift for 2429 sources and identify 124 with
incorrect NED redshifts. We obtain IRS-based redshifts for 568 IDEOS
sources without optical spectroscopic redshifts, including 228 with no
previous redshift measurements. We provide the entire IDEOS redshift
catalogue in machine-readable formats. The catalogue condenses our
compilation and verification effort, and includes our final evaluation
on the most likely redshift for each source, its origin, and
reliability estimates.
Description:
The extragalactic sample that constitutes IDEOS is a subset of the
Spitzer/IRS atlas CASSIS.
The IDEOS sample includes all the spectra from CASSIS of extragalactic
sources beyond the Local Group. We use the latest version of CASSIS
(v7.0) and a careful stitching procedure to maximize the data
quality. Optical counterparts were identified from correlation with
the NED database, taking into account the uncertainty in the
extraction coordinates, PSF beam size, and the redshifts of the
candidates.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableb1.dat 206 3532 IDEOS redshift table
--------------------------------------------------------------------------------
See also:
http://cassis.sirtf.com/atlas : CASSIS Home Page
http://ideos.astro.cornell.edu/redshifts.html : IDEOS redshift catalogue
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- AOR_ID AOR + Cluster ID
13- 21 F9.5 deg RASdeg Requested right ascension of Spitzer/IRS
observation (J2000)
23- 31 F9.5 deg DESdeg Requested declination of Spitzer/IRS
observation (J2000)
33- 41 F9.5 deg RAdeg Right ascension of CASSIS extracted
source (J2000) (1)
43- 51 F9.5 deg DEdeg Declination of CASSIS extracted
source (J2000) (1)
53- 82 A30 --- NEDname NED name of source in zfinal table
84- 90 E7.5 --- zfinal Final, best redshift for the source
92- 98 A7 --- r_zfinal Origin of best redshift (2)
100-111 A12 --- q_zfinal Verification status for the redshift (3)
113-119 E7.5 --- zNED Default NED redshift
121-125 A5 --- zNEDtype Type of default NED redshift (4)
127-134 E8.5 --- zMCPL Redshift from IRS spectrum (maximum combined
pseudo-likelihood method (MCPL) algorithm)
136-142 F7.5 --- gamma gamma parameter for zMCPL redshift (5)
144-149 F6.2 --- R R parameter for zMCPL redshift (5)
151-156 F6.4 --- A ? Reliability of zMCPL redshift
(A=gamma+log10(R)/2)
157 A1 --- n_A [i] i for -infinity
160-165 E6.4 --- P005 Outlier probability for zMCPL at delta=0.005
threshold, P0.005(A) (6)
167-172 E6.4 --- P05 Outlier probability for zMCPL at delta=0.05
threshold, P0.05(A) (7)
174-180 F7.5 --- zNEDalt ?=0 Alternate NED redshift (preferred value)
182-185 A4 --- zNEDalttype [SPEC ? -] Type of alternate NED redshift
187-193 E7.5 --- zIRSalt ?=0 Alternate IRS redshift (MCPL algorithm)
195-196 I2 --- order [0/20]? Order number of IRS redshift
solution by decreasing realiability
198-204 F7.5 --- Pmulti ?=0 Probability of agreement by chance
between zIRS and zNED
206 I1 --- Qf [1/3]? Quality flag of zfinal redshift (8)
--------------------------------------------------------------------------------
Note (1): CASSIS, Lebouteiller et al., 2011ApJS..196....8L 2011ApJS..196....8L, 2015ApJS..218...21L 2015ApJS..218...21L.
Note (2): Origin could be
zIRS, zIRSalt, zIRSeye, zNED or zNEDalt
Note (3): Verification status for the redshift could be
VERIFIED, CONFIRMED, ROBUST, PROBABLE, UNCHALLENGED or UNCERTAIN
Note (4): Type of default NED redshift could be
IRS, PHOT, SPEC, SPEC? or ?
Note (5): gamma is the value of Q(z) evaluated at the preferred solution and
normalized to the integral of Q(z) over the entire redshift search range,
while R is the ratio between the first and second highest values of Q(z),
where Q(z) is the combined pseudo-likelihood.
Note (6): Probability of finding zIRS within δ<0.005 from NED.
Note (7): Probability of finding zIRS within δ<0.05 from NED.
Note (8): Quality flag as follows:
3 = very reliable 'confirmed' and 'verified' redshifts
2 = reliable redshifts (sources with 'unchallenged', 'probable', or 'robust'
status)
1 = uncertain redshifts
--------------------------------------------------------------------------------
History:
Copied at http://ideos.astro.cornell.edu/redshifts.html
(End) Patricia Vannier [CDS] 28-Jul-2016