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ESOLV: ESO Catalogue of Galaxies
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ESOLV: ESO Catalogue of Galaxies
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Table name: ESOLV Records: 15467 Version: Lauberts-Valentijn 1989 Spectral Band: OPT,Bphoto,Rphoto Kind of Object: Galaxy Mode: Morphology,Survey PreView: Yes Coordinates: B1950
Since all the information present in ESO-Uppsala catalogue was acquired by visual inspection of the plates, it was decided to undertake a follow up study, in which computerized processing takes the central place. Hereafter we will refer to the present study and its results as ESO-LV. The visually obtained results of ESO-Uppsala catalogue are quite complementary to the automatic processed data of ESO-LV. It should be noted however, that the original ESO-Uppsala catalogue catalogue was used as a reference data base for the processing of ESO-LV and that without this reference this project would not have been possible.
The prime objective of ESO-LV was to obtain accurate magnitudes for the ESO-Uppsala catalogue galaxies. To this end target galaxies have been scanned on both the 407 original ESO Quick Blue survey plates and on the 407 original ESO Red survey plates. It was soon realized that the scanned images of the galaxies could also be used to obtain other photometric and structural parameters.
The scan aperture was always 20x20 microns, using a 10x magnification objective. A smaller aperture, of say 10 microns, was rejected from the beginning because of uncotrollable focus variations. The step size, 20 microns, had to be kept relatively large in order to save time. With a plate scale of 67.5"/mm, the pixel size of 1.35" was significantly smaller than the average seeing of 2".
A full description of the automated parameter extraction procedures is given in Section 5 of [1]. The printed version of the newly determined parameter values, which can be found at the end of this book, contains 37 different entries, while the digitized versions contain up to 180 entries, including radial surface brightness profiles. This data base (180 entries for 16000 galaxies) can be considered the principal result of the project. The data will be made available to the astronomical community in several forms: on the ESO data base computer (IDM), as a MIDAS table on the ESO VAX computers and on magnetic tape. Beside that, the images used in this survey and calibrated to surface brightness are resident on an ESO optical disk drive (see [1] Section 10).
All plates have been calibrated by using 'standard' galaxies, for which aperture photometry has been accumulated both from the literature and from our own photo-electric observations. The photo-electric (p.e.) observations and the conversion to a 'standard system' are described in [1] Section 3. A previous version of the p.e. data base has been published in ESO Scientific report No 3. The procedures followed for scanning and calibrating the plates are described in [1] Section 4. The calibration coefficients of the 814 plates form an interesting data base on the properties of sensitized (Red) and unsensitized (Blue) plates. At the end of Section 4 we present some statistics on these quantities, also including the sky brightness values.
The accuracy of the derived photometry is discussed in [1] Section 7. Both internal consistency checks and comparisons with other photometric observations are presented. The nominal accuracy of total magnitudes, Btot, is expected to be better than 0.09, most likely around 0.06, for galaxies brighter than Btot= 15, while surface brightness (mu) profiles are found to have residuals from photoelectric photometry less than 0.15 for 20 < (mu)B < 24.
The photometric and structural parameters have been used to determine morphological types for ~ 3500 galaxies that could not be classified in ESO-Uppsala catalogue, mostly because they were too faint. The availability of colours and profile gradient parameters allowed us to evaluate in an automated mode the expected morphological type. We have also made extensive use of the recently published classifications by Corwin et.al.(1985). The morphological re-classification is described in [1] Section 6.
A strong aspect of the ESO-LV data base is that data have been acquired in a homogeneous fashion for all sorts of galaxies in various environments. Thus it appears that scientific studies of galaxy properties as function of environment might be fruitful with this data base. In order to facilitate such studies, we have attempted to construct a local projected galaxy density parameter, despite the lack of redshifts for the majority of the catalogue galaxies. Data on Southern Clusters from Abell et.al.(1989) have been incorporated in the galaxy density parameters. A full description is given in [1] Section 8.
In [1] Section 2 we give an account on the construction of the sample, while in Section 9 an analysis is presented of the selection effects inherent in a diameter selected sample, in addition to a discussion on the completeness of the sample with respect to its selection criteria. A Vmax complete sample is drawn from the total sample.
Name Col Fmt Meaning a_e 125 F8.1 ABe aperture of circle enclosing half total B light ab_ado 116 F8.2 a_b0 a/b adopted for computing parameters in ellipses ab_oct 113 F8.2 a_b0 a/b from ellipse fit to B octants b_b25 19 F8.2 B25 B mag within ellipse at B sb=25 mag/sq arcs b_b26 17 F8.2 B26 B mag within ellipse at B sb=26 mag/sq arcs b_sky 107 F8.2 (mu )BskyBlue sky background, mag/sq arcsec b_tot 15 F8.2 BT B mag, total br_10 100 F8.2 (B - R)10"B-R integrated in central 10" diameter circle br_d 171 F8.2 4(B - R) difference of B-R of regs (outside - inside) B eff radius br_e 99 F8.2 (B - R)e B-R integrated in ellipse enclosing half total B light br_t 101 F8.2 (B - R)T B-R total colour bs_0 104 F8.2 (mu )B0 average B surface brightness, within 10" circ aperture bs_e 143 F8.2 (mu )Be B sb at B half total light (only if d_e > 10") bt_flg 11+112 A1 BflagNresB number of radii susp saturated: - replaced with photoelectric data 0 deblended 1,2 Number of radii suspected saturated c 182 I4 sample Completeness: 0=not, 1=E/U diam 1', 2=Vmax complete cz 13 F6.0 cz radial velocity, helio-centric, km/sec d25 109 F8.1 DB25 major diameter (arcsec) of ellipse at B sb 25 mag/sq arcs d26 110 F8.1 DB26 major diameter (arcsec) of ellipse at B sb 26 mag/sq arcs d27 111 F8.1 DB27 major diameter (arcsec) of ellipse at B sb 27 mag/sq arcs d70 119 F8.1 DB70 major diameter (arcsec) of ellipse at B 70% total B light d80 120 F8.1 DB80 major diameter (arcsec) of ellipse at B 80% total B light d90 121 F8.1 DB90 major diameter (arcsec) of ellipse at B 90% total_B light d_e 122 F8.1 DBe major diameter (arcsec) at B half total light dec 10 F8.3 DEC Dec (1950), degrees descr 190 A52 descriptionOriginal classification and comments (old +new) dnb 152 F8.0 Dnb distance to nearest neighbour, arcsec dsnb 155 F8.0 Dsnb distance to second nearest neighbour, arcsec e_cz 14 F6.0 czerr error in radial velocity eso 1 I8 ESOindentESO field number / galaxy number PIDM.FMT 890502 ic 3 I6 IC IC number (if negative then additional NGC no) mt 7 F6.1 Type morphological type T [-6,+10], revised according to S. A value of -9.0 means unknown nearn 151 I8 IDnb identifier of nearest neighbour ng_sp 131 F8.3 Nsp No of galaxies/sq degree, Spir, 0 Type < 8.5. A value of -9.000 means unknown ng_t 127 F8.3 Ntot Total no of galaxies/sq degree in 1 degree radius circle. A value of -9.000 means unknown ngc 2 I6 NGC NGC number (if negative then additional IC no) noct_b 150 F8.3 NBoct exponent of fit generalized law to B octants noct_r 162 F8.3 NRoct exponent of fit generalized law to R octants pa_ado 118 F8.1 p:a:0 position angle adopted for parameters in ellipses pa_oct 114 F8.1 p:a:1 position angle from ellipse fit to B octants r_a 9 F8.3 RA R.A. (1950), degrees r_b25 20 F8.2 R25 R mag within ellipse at B sb=25 mag/sq arcs r_b26 18 F8.2 R26 R mag within ellipse at B sb=26 mag/sq arcs r_sky 108 F8.2 (mu )RskyRed sky background, mag/sq arcsec r_tot 16 F8.2 RT R mag, total, with same limiting boundary as B_TOT rs_0 146 F8.2 (mu )R0 average R surface brightness, within 10" circ aperture rs_e 144 F8.2 (mu )Re R sb at B half total light (only if d_e > 10 arcsec) rt_flg A1 R number of radii susp saturated (-: repl with pe, 0: deblended) s 8 I4 Tflag Source for T: 1=vis revised, 2=Corwin, 3=T_OLD, 4=T_PAR secnb 154 I8 IDsnb identifier of second nearest neighbourLast modified: Tue May 27 1997 10:13:32 MET DST