The following document lists the file notes.txt
from catalogue VII/221.
A plain copy of the file
(without headers/trailers) may be downloaded.
-------------------------------------------------------------- Explanatory Notes for IRAS PSCz redshift survey data files: Version 2.2, Will Saunders, Will Sutherland, May 2000 -------------------------------------------------------------- This file is "notes.txt" pscz.dat is the current public version 2.2 of the PSCz survey. This file should be read in conjunction with the catalogue paper 'The PSCz catalogue', Saunders etal 2000MNRAS.317...55S ("psczcat.tex/psczcat.ps"). There is a short version of the catalogue, "psczvs.dat", containing sufficient information for most studies and containing one line per source. The main catalogue is "pscz2_2.ori", with 4 lines/source. Both versions contain the same list of 18351 sources; some of which are not galaxies and some of which are multiple entries for the same galaxy as described below. There are in total 15411 galaxies or possible galaxies, for which redshifts are available for 14677. The galaxies without redshift are mostly distant or at low latitude, as described below. Many of these galaxies have now been observed as part of the BTP project (Saunders et al 1999, astro-ph9909174), and their redshifts will be included in future revisions of the catalogue. History: Version 2.1 was released in January 2000. Version 2.2 is identical except that the MHCONB field was wrongly set to zero for most sources and is now corrected. Version 2.2 is the one submitted to CDS to accompany publication of the catalogue paper. Sources are ordered by their unique identifier, e.g. A/111/011, in sectors based on POSS-I or SRC plates. The letter (A-L) defines broad declination stripes 10-30 degrees wide, the first number identifies the POSS-I or SRC plate within the strip (roughly RA ordered), and the second number uniquely identifies the source on that plate. Numbers less than 300 are QIGC sources (Rowan-Robinson et al 1990, MNRAS 253 485). Local Group galaxies are deliberately excluded from the catalogue. There is a supplementary file "ilg.dat" of Local Group members with 60um fluxes 0.6Jy or greater. The area of sky excluded from the survey is defined by the mask "psczmask.dat", and consists of the Magellanic clouds, areas with inadequate or confused IRAS coverage, or with extinction great enough (A_B>2^m) to make optical followup uncertain. Remaining sky coverage is 10.56 ster. There is also a more conservative mask "himask.dat" available, excluding in addition all areas with A_B>1^m (leaving 9.06 ster). Both masks are defined by a list of excluded 'lune bins' and are read in by the fortran77 routine rdmask in "qcd.f" through unit 9, to create the logical array LMASK (41167 elements) stored in the common block DWLCOM. Note that LMASK is false for masked bins. The routine "g2bin.f" turns arbitrary (l,b) into bin number, using workhorse routines in "qcd.f". No attempt was made to achieve completeness for faint galaxies (B or b_J>19.5^m). It is estimated that this introduces incompleteness at distances z_c > 0.1 /10**(0.2*(A_B+0.1*A_B**2)). The incompleteness is worst towards the anticentre and |b|<10. Within this distance, completeness and uniformity are estimated as good to a few % outside hibpscmask.dat and to 10% at lower latitudes. Our estimate of the selection function is given by "psi.f". The selection function is defined as the expected number density (per h^-3Mpc^3) of galaxies at distance r (h^-1Mpc), in the absence of clustering. The estimate given assumes a Euclidean geometry for both distance and volume element, i.e. r = v_gal/2998 , dV = r^2 dr . For this calculation heliocentric velocities have been corrected only to bring them to the Local Group frame, v_gal = v_hel + 300 sinl cosb. Because the fluxes are quoted to 2 decimal places only, the actual flux limit is 0.595Jy at 60um. Redshift references are given in igalrefs.txt Variable names: For both short and main catalogue, all field names use the following default for initial letters: I-N = integer, C = character, else real. Where necessary, field names have been prefixed by I, C or A. The format for the short version "pscz1.2_vs.dat" is: 1 a9 CSEC9 : e.g. A/111/011, PSCz identifier, see above. 1x 11 a1 CPSCZ : source category, see notes 12 a1 CZSTAT : redshift status, see notes 13 a2 CLASS : identification classification, see notes 15 i8.7 IQLON : RA hhmmsss (1950) 23 i8.6 IQLAT : Dec ddmmss (1950) 31 2f6.1 GLON,GLAT : Galactic coords l,b (degrees) 43 f8.2 F3 : 60um flux in Jy, not colour corrected 51 i6 IVHEL : heliocentric velocity, cz 57 i4 IVERR : uncertainty 61 i3 IVREF : reference (see igalrefs.txt) 64 a12 CONAME : optical name if any, mostly from PGC 76 i4 I100B : I_100 sky brightness for that lune bin (MJy/sr) 80 f5.2 ABB : estimated extinction A_B for that lune bin 1x 86 a1 CHSD : High source density (HSD) flag as in PSC 87 i2 MHCONB : number of HCONS for that lune bin 89 f6.2 R43 : 100um/60um flux ratio, negative if upper limit at 100um. 95 i6 NLBIN : lune bin number Line length 100. Full read statement: character*1 czstat,cpscz,chsd character csec9*9,class*2,coname*12 read(?,401) csec9,cpscz,czstat,class, # iqlon,iqlat,glon,glat,f3, # ivhel,iverr,ivref, # coname,i100b,abb,chsd,mhconb,r43,nlbin 401 format(a9,1x,2a1,a2,i8.7,i8.6,2f6.1,f8.2,i6,i4,i3, # a12,i4,f5.2,1x,a1,i2,f6.2,i6) ---------------------------------------------------------------- NOTES: CPSCZ: source category: = PSC (or PSC reject file) source, and not a large-diameter optical galaxy. + addscanned large optical galaxy added to PSCz. - PSC source associated with a "+" addscan object (normally excluded). & high latitude PSCz source, but in a bin excluded by psczmask.dat . ^ high latitude optical galaxy, in a bin excluded by psczmask.dat . CZSTAT: redshift status: 1 PSCz redshift, excellent quality 2 PSCz redshift, good quality 3 PSCz redshift, low s/n but secure 4 PSCz redshift, marginal detection, unreliable l literature redshift, see IVREF for details. p private communication, see IVREF for details. q redshift from QDOT or QCCOD # redshift wanted for PSCz, but still unknown x Give up, too optically faint (B or b_J > 19.5 mag) - Don't need it: galactic source, duplicate, part of larger galaxy etc. CLASS: object classification from optical data etc. g : galaxy or galaxies gf: faint galaxy, B or b_j > 19.5 mag. go: optical galaxy with 1D addscanned flux gr: Rice et al galaxy with 2D coadded photometry ss: Star, confirmed spectroscopically (by us, 1.2 Jansky or de Grijp) bs: Bright star from plate or telescope TV, no spectrum is: Star from IRAS colours and plate/TV appearance c : Cirrus pn: Planetary Nebula rn: Reflection Nebula h2: HII region zz: Other galactic source lm: in Large Magellanic Cloud sm: in Small Magellanic Cloud vb: Visually blank on sky survey plates, no non-stellar id kb: K' image blank, no non-stellar id rb: Radio blank, no 6 or 20cm id de: delete from catalogue, part of extended galaxy d1: delete from catalogue, broken up 1HCON source already listed elsewhere du: deleted optical galaxy, part of multiple system unresolved by IRAS dr: deleted optical galaxy, already in as Rice etal galaxy ao: PSC source associated with addscanned optical galaxy ar: PSC source associated with Rice etal optical galaxy The divisions above between Galactic classifications 'pn','rn' etc are not rigorous. The CLASS='go' and 'gr' sources were optically selected (see accompanying paper) and their IRAS fluxes determined by addscanning or coadding. Their fluxes F(1-4) are addscan or coadded fluxes, reduced by a factor 1.1 to bring them statistically into line with PSC fluxes. Where the resulting flux F(3) is 0.6 Jy or greater, they are added to the catalogue and flagged with CPSCZ='+'. There are 1467 such sources representing 1402 individual galaxies resolved by IRAS. The associated PSC source is retained in the catalogue, but is flagged as CPSCZ='-' and will normally be excluded (1290 sources). Thus, to select all the galaxy sources from PSCz outside the mask psczmask.dat, using addscan fluxes for the large-diameter galaxies (the default option), use : if( ((cpscz.eq.'=').or.(cpscz.eq.'+')) .and. (czstat.ne.'-')) ... This will select 15411 unique galaxies, of which: 542 have czstat = 'x' (not observed because too faint optically, or blank), 192 have czstat = '#' (redshift wanted but still unknown or unreduced), 14677 have an observed redshift. Alternatively, to create a purely point-source-filtered, IRAS-selected catalogue, keep the CPSCZ = '-' sources but reject the addscanned '+' sources : if( ((cpscz.eq.'=').or.(cpscz.eq.'-')) .and. (czstat.ne.'-')) DO NOT use both the CPSCZ = '+' and '-' categories at the same time. There are 38 PSC sources satisfying the colour and flux criteria for the PSCz, but lying so close to the coverage gaps that they fall into the lune bins used to define the gaps. They are listed in the separate files "pscz2.1_cg_vs.dat" and "pscz2.1_cg.dat", and are flagged as CPSCZ='&'. These files also include a further 22 optically-selected galaxies similarly falling under the mask, but for which addscan data exists; these are flagged as CPSCZ='^'. Note that inclusion in the PSC demands 2 or more HCONS, while the addscan only requires 1, so the sky coverages are unequal. There is unlikely to be much reason to use these sources, but they are included for completeness. These supplementary files have the same formats as the main catalogue files. ----------------------------------------------------------------------- FULL CATALOGUE FORMAT: ----------------------------------------------------------------------- The full catalogue is pscz2.1.dat ; it has FOUR lines per source as follows. * means a quantity from PSC, see "IRAS Catalogs and Atlases", Beichman et al, 1988, NASA Reference Publication 1190, Volume 1. First line: 1x a11 CNAME : name e.g. Q12345+4856 13 i8.7 IQLON : RA, 1950 (HHMMSSS) * 21 i8.6 IQLAT : Dec (DDMMSS) * 29 4f8.2 F(4) : Fluxes at 12,25,60,100um (Janskies, non colour-corrected) 1x 62 4i1 IQ(4) : Flux origin and quality flag, see below. 1x 67 4i1 ISES(4): SES flag, derived from SES2, see below. 1x 72 4i3 IU(4) : flux uncertainty (%) * 1x 85 3i3 MINE,MAJE,IPOSE : Minor, major axes, PA, of 2 sig err ellipse* 1x 95 i1 IC(1) : CIRR1 flag * 96 i1 IC(2) : CIRR2 flag * 97 i3 IC(3) : CIRR3 flag * 1x 101 4a1 CC : Correlation Coefficient * 1x 106 a1 CONF : Confusion flag * 107 a1 CDISC : Discrepant flux flag * 108 a1 CHSD : HSD flag * 1x 110 2i1 IPNEARH,IPNEARW: Nearby confirmed sources * 1x 113 4i1 ISES1(4): nearby seconds confirmed extended sources * 117 i5 ISNR3 : 10 x s/n at 60um * 122 i2 NHCON : Number of HCONS with source detected * 124 i2 MHCON : Number of HCONS covering source * 1x 127 i4 IFCOR3 : flux correction factor, see below. 131 2x (line length a132) Second line: Optical information. (APM info is for candidate with best likelihood, not necessarily the correct id or that for which redshift is taken). 1x 2 a5 CPLATE : Plate number (POSS or SRC) 1x 8 a7 CNOM : Nominal plate centre 1x 16 i3.3 NUM : Identifier for igal source on this plate 1x 20 i2.2 IARH : RA hours of best optical id 22 i2.2 IARM : RA mins 24 i2.2 IARS : RA secs, integer part 26 f3.2 ARS : RA secs, decimal part (so 02.44 => 02 + .44) 1x 30 a1 CADSN : Dec Sign 31 i2 IADD : Dec deg 33 i2 IADM : Dec mins 35 i2.2 IADS : Dec secs, integer part 37 f2.1 ADS : Dec secs, decimal part 1x 40 2i3 IADX,IADY : Delta X, Y from IRAS posn (arcsecs) 46 f4.1 ALK : log likelihood 50 i3 IREL : % chance this is right id 53 a1 CAND : Candidate A,B etc 54 i1 IOPT : Schmidt plate material (see below) 55 f6.2 AMAG : APM magnitude 61 3i3 IAD1,IAD2,IAPA : APM d1,d2 (arcsecs), PA 70 f7.3 AMU : surface brightness (mags/arcsec^2) 77 i2 IDTYPE 79 a12 CONAME : Optical name 91 f6.2 AMZW : Zwicky/De Vauc magnitude 97 f5.1 D1X : RC3/UGC/MCG/ESO diameter (X for CATX) 102 i3 IAR : 100*(d25/D25) 105 i6 IVHEL : Best heliocentric Vel from Literature or PSCz. 111 i4 IVERR : Error 115 i3 IVREF : Reference 118 i6 IVHELP : PSCz heliocentric Vel 124 i4 IVERRP : Error 128 i3 IVREFP : Reference 131 i2 IT : De Vauc Type, 99 = unknown 133 a9 CPGC : PGC name (line length a141) Third line: 1 2f9.4 RAD,DECD: RA, Dec (equinox B1950, degrees) 19 2f9.4 GLON,GLAT: Galactic longitude, latitude (degrees) 37 i6 IVGAL : Velocity cz in LG frame (IVHEL + 300 sin(l) cos(b)) 43 f5.1 DIST : Distance (Rowan-Robinson 1988) 48 i4 ICLUS : Cluster id (Rowan-Robinson 1988) 52 1x 53 2f5.2 ALI4,ALI4B: log10(100um background in MJy/sr), (see note). 63 I6 NLBIN : lune bin as from P2BIN 69 1x 70 A2 CLASS : optical classification (see earlier note) 72 1x 73 A5 CSEC : PSC-z sector, e.g. A/123 78 2i4 PLATEX,PLATEY : posn from bottom left corner of Schmidt plate in mm 86 1x 87 a1 CSTAT : optical material E,O,R,J,X,Polaroid,Scan 88 a1 CAREA : h=high|b|, p=other PSCz, l=low|b|, c=in coverage gaps 89 a1 CZSTAT : Redshift status (see earlier note) 90 1x 91 a1 C12CLASS: 1.2Jy classification 92 2f8.2 F3PSC,F4PSC : Original PSC fluxes * 108 f5.2 ABB : Extinction A_B in lune bin derived from 100 um background, dust temp corrected (see note). 113 1x 114 a1 CPSCZ: : Source category (see earlier note) 115 i2 MHCONB : 2/3 HCON sky, calculated on lune bin basis 117 1x 118 a1 CQDOT : q = in QDOT 1-in-6 sample. 119 i4 IW20 : HI (21cm) 20% vel width : -999 = private, -997 = not reduced, -996 = to be observed, -994 = detected OK but not measured, -1 = non-detection, -2 = confused, -995 = s/n < 5 123 i2 IW20E : error 125 i4 IW50 : HI 50% vel width, codes as IW20 129 i2 IW50E : error 131 i2 IHIREF : HI reference. (line length a132) 4th line: Addscan information 1 4f9.3 FP : Addscan flux using point source template 37 1x 38 4i4 IEP : Statistical error in mJy. 54 1x 55 4i1 IBP : 1 for background fit, 0 for none (extended or bright) 59 4f9.3 FE : Rice or Yahil/Addscan flux for source with size given by WIDTH2. 95 1x : 96 4i4 IEE : Statistical error in mJy. 112 1x 113 4i1 IBE : 1 for background fit, 0 for none (extended or bright), 2 = Rice. 117 f8.4 WIDTH2 : best fit width**2 at 60um (arcmin**2) 125 f8.4 EWIDTH2 : error on WIDTH2 Line length a132 --------------------------------------------------------------------------- NOTES: * means quantity taken from PSC, see Beichman et al 1988 Explanatory Supplement for more information. IRAS Names: digits hhmmm+ddmm as in PSC. The initial letter means: Q: from QIGC P: from PSC R: from PSC reject file O: from optical catalogue In the long file, the CSEC9 name is split into two parts: the plate (e.g. A/111) is stored as 'CSEC' and the source identifier (e.g. 011) as 'NUM'. Flux qualities IQ(4): 1 = upper limit, 2 = moderate, 3 = OK, 4 = new HCON merged flux, 5 = addscanned flux/1.1, 6 = coadded flux, 7 = addscanned flux with point source template, 9 = single HCON. Extended source flags ISES(4): 1 = flagged as confirmed extended source, 2 = in SSS catalog, 3 = in Large Galaxy Catalog, 4 = addscan flux, 5 = addscan flux, source is double, 6 = coadd flux, 7 = coadd flux, source is double, 8 = addscanned flux, Yahil software used, 9 = addscanned point source flux, Yahil software used. 2-8 date from QIGC, there should be none in here except class='ds' sources. IFCOR3 = NINT(FCOR(3) *1000), FCOR = correction factors applied to correct for overestimated faint fluxes as in Explanatory Supp. For the supplementary single-HCON sources, we have applied a factor of 1.121, as used in the PSC for 2 out of possible 4 HCON detections. For merged single-HCON sources, unmerged in PSC due to software errors, we have corrected the correction factors accordingly. IOPT: source of Schmidt plate material. 1 = POSS-O/APM, 2 = SRC-bJ/APM, 3,4,5 = SRC-bJ/Cosmos, 6 = SR/Cosmos, 7 = POSS-E/APM, 9 = RC3 diameters . The optical information from plate scans is for the candidate with the best likelihood, not necessarily that for which the redshift is taken. The probability that these are the same depends strongly on latitude; at high latitude they are very reliable. The optical material is heterogeneous and except for IOPT=2 is uncalibrated. IOPT=6 magnitudes are estimated red mags, otherwise B or b_J. Due to saturation, magnitudes brighter than about 16 mag are very unreliable. Where a correct bright galaxy has been misclassified by the source-finding software as a star, the magnitude will be meaningless. ALI4, ALI4B, ABB: 100um backgrounds from Rowan-Robinson et al 1991, MNRAS 249, 729. ALI4 is the background in a 0.5 degree beam centered on the source, corrected for that point source only. ALI4B is the background averaged over lune bin, and is corrected for all IGAL sources. ABB is based on ALI4B, and has been crudely corrected for temperature variation of dust across the galaxy. MHCONB is the number of HCON coverages, crudely estimated from Explanatory Supp Fig I.C.1, for comparing source counts, fluxes etc. The HI data is extremely heterogeneous in quality, reduction and linewidth definition. ------------------------------------------------------------- Full FORTRAN read statement for pscz2.1.dat : real f(4),fc(4),fp(4),fe(4) integer iq(4),ises(4),iu(4),ises1(4),ic(3), # iep(4),iee(4),ibp(4),ibe(4) character cname*11,coname*12,cplate*5,csec*5,cnom*7,cpgc*9,class*2, # cdum*2 character*1 cc(4),conf,cdisc,chsd,cadsn,cstat,czstat, # c12class,cpscz,cqdot,cand,carea read (?,101,end=?) cname,iqlon,iqlat,f,iq,ises,iu, # mine,maje,ipose,ic,cc,conf,cdisc,chsd, # ipnearh,ipnearw,ises1,isnr3,nhcon,mhcon,ifcor3,cdum 101 format(1x,a11,i8.7,i8.6,4f8.2,2(1x,4i1),1x,4i3,1x,3i3, # 1x,2i1,i3,1x,4a1,1x,3a1,1x,2i1,1x,4i1,i5,2i2,1x,i4,a2) read (?,102) cplate,cnom,num,iarh,iarm,iars,ars, # cadsn,iadd,iadm,iads,ads,iadx,iady,alk,irel,cand,iopt,amag, # iad1,iad2,iapa,amu, # idtype,coname,amzw,d1x,iar, # ivhel,iverr,ivref,ivhelp,iverrp,ivrefp,it,cpgc 102 format(1x,a5,1x,a7,1x,i3.3,1x,3i2.2,f3.2,1x,a1,3i2.2,f2.1, # 1x,2i3,f4.1,i3,a1,i1,f6.2,3i3,f7.3,i2,a12,f6.2,f5.1,i3, # 2(i6,i4,i3),i2,a9) read(?,103) rad,decd,glon,glat,ivgal,dist,iclus, # ali100,ali100b,nlbin,class,csec,iplatex,iplatey, # cstat,carea,czstat,c12class, # f3psc,f4psc,abb,cpscz,mhconb,cqdot, # iw20,iw20e,iw50,iw50e,ihiref 103 format(4f9.4,i6,f5.1,i4,1x,2f5.2,i6,1x,a2,1x,a5,2i4,1x,3a1,1x,a1, # 2f8.2,f5.2,1x,a1,i2,1x,a1,2(i4,i2),i2) read(?,104) fp,iep,ibp,fe,iee,ibe,width2,ewidth2 104 format(2(4f9.3,1x,4i4,1x,4i1),2f8.4) If there are problems that cannot be resolved by careful reading of these notes or the accompanying paper, please contact Will Saunders () or Will Sutherland ().
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