2004MNRAS.354.1011Y


C.D.S. - SIMBAD4 rel 1.7 - 2020.02.21CET11:32:37

2004MNRAS.354.1011Y - Mon. Not. R. Astron. Soc., 354, 1011-1019 (2004/November-2)

Total magnitudes of Virgo galaxies - III. Scale errors in the Reference Catalogue of Bright Galaxies T system and light-profile distortion by resolution-degrading and differential-distance effects.

YOUNG C.K.-S.

Abstract (from CDS):

We investigate the BT magnitude scales of the Second and Third Reference Catalogues of Bright Galaxies, finding both scales to be reasonably reliable for 11.5 ≲Bt≲ 14.0. However, large-scale errors of 0.26 and 0.24mag per unit mag interval respectively are uncovered for early-type galaxies at the bright ends, whilst even larger ones of 0.74 and 0.36mag per unit mag interval are found for galaxies of all morphological types at the faint ends. We attribute this situation to several effects already discussed by Young et al. and Young (Paper I), including the application of relatively inflexible growth-curve models that are only in a few specific cases appropriate to the galaxies concerned. Of particular interest to this study though, we find that the apparent profile shapes of giant galaxies in the Virgo direction of cz < 15000 km/s tend to be less centrally concentrated the greater their distance. This demonstrates that even for relatively nearby galaxies, the distortion of the overall shapes of light profiles by resolution-degrading effects such as seeing and data smoothing, as originally predicted and modelled by Young & Currie and Young et al., is a significant effect. It is, therefore, not good practice simply to extrapolate the profiles of galaxies of identical intrinsic size and intrinsic profile shape (i.e. identical morphology) by means of the same growth-curve model, unless the galaxies are known a priori to be at the same distance and unless their photometry is of the same angular resolution. We also investigate the total-magnitude scale of the catalogue of photometric types of Prugniel & Héraudeau, finding it to be much more reliable than the BT one. However, we argue that photometric type is really a measure of apparent profile shape (i.e. intrinsic profile shape after scale reduction on account of distance followed by convolution with a seeing disc and often a smoothing function as well). Strictly, it should therefore only be applicable to comparisons between galaxies that are already known to be at similar distances provided that their photometry is also of similar angular resolution. Clearly, this must complicate attempts to construct quantitative morphological classification schemes for galaxies.

Abstract Copyright: 2004 RAS

Journal keyword(s): catalogues - galaxies: clusters: individual: Virgo - galaxies: distances and redshifts - galaxies: fundamental parameters - galaxies: photometry

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 NGC 147 GiG 00 33 12.120 +48 30 31.46   12.0 9.5     ~ 613 1
2 NGC 1336 GiG 03 26 32.199 -35 42 48.86   13.12   11.95   ~ 103 0
3 NGC 1351 GiG 03 30 34.983 -34 51 14.22   12.30   10.85   ~ 152 0
4 NGC 1374 GiP 03 35 16.598 -35 13 34.50 12.46 11.97 11.08 10.59   ~ 250 1
5 NGC 1399 BiC 03 38 29.083 -35 27 02.67 11.05 9.74 9.59 8.12   ~ 1435 1
6 ACO S 373 ClG 03 38 30 -35 27.3           ~ 1509 0
7 NGC 1419 GiG 03 40 42.120 -37 30 39.09   13.56   12.07   ~ 109 0
8 NGC 1427 GiG 03 42 19.4447168502 -35 23 33.193682690   11.89   10.44   ~ 245 0
9 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 14544 1
10 NAME Vir I ClG 12 26 32.1 +12 43 24   10.00 8.49     ~ 5723 0
11 NAME Local Group GrG ~ ~           ~ 6802 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2004MNRAS.354.1011Y and select 'bookmark this link' or equivalent in the popup menu


2020.02.21-11:32:37

© Université de Strasbourg/CNRS

    • Contact