THE GLOBULAR-CLUSTER SYSTEMS OF NGC-1400 AND NGC-1407

Citation
Km. Perrett et al., THE GLOBULAR-CLUSTER SYSTEMS OF NGC-1400 AND NGC-1407, The Astronomical journal, 113(3), 1997, pp. 895-904
Citations number
43
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046256
Volume
113
Issue
3
Year of publication
1997
Pages
895 - 904
Database
ISI
SICI code
0004-6256(1997)113:3<895:TGSONA>2.0.ZU;2-Z
Abstract
The two brightest elliptical galaxies in the Eridanus A group, NGC 140 0 and NGC 1407, have been observed in both the Washington T-1 and Kron -Cousins I filters to obtain photometry of their globular cluster syst ems (GCSs). This group of galaxies is of particular interest due to it s exceptionally high M/L value, previously estimated at similar to 300 0h, making this cluster highly dark-matter-dominated [Gould, ApJ. 403, 37 (1993)]. NGC 1400's radial velocity (549 km/s) is extremely low co mpared to that of the central galaxy of Eridanus A (NGC 1407 with upsi lon(circle dot)=1766 km/s) and the other members of the system, sugges ting that it is a foreground galaxy projected by chance onto the clust er. Using the shapes of the globular cluster luminosity functions, how ever, we derive distances of 17.6+/-3.1 Mpc to NGC 1407 and 25.4+/-7.0 Mpc to NGC 1400. These results support earlier conclusions that NGC 1 400 is at the distance of Eridanus A and therefore has a large peculia r velocity. Specific frequencies are also derived for these galaxies, yielding values of S-N=4.0+/-1.3 for NGC 1407 and S-N=5.2+/-2.0 for NG C 1400. In this and other respects, these two galaxies have GCSs which are consistent with those observed in other galaxies. (C) 1997 Americ an Astronomical Society.