DETECTION OF THE GLOBULAR-CLUSTER POPULATION AROUND NGC-7814

被引:8
作者
BOTHUN, GD
HARRIS, HC
HESSER, JE
机构
[1] USN,OBSERV,FLAGSTAFF,AZ 86002
[2] NATL RES COUNCIL CANADA,HERZBERG INST ASTROPHYS,DOMINION ASTROPHYS OBSERV,VICTORIA V8X 4M6,BC,CANADA
关键词
D O I
10.1086/133111
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We report the statistical detection of 120 +/- 225 globular clusters in fields surrounding the edge-on S03 galaxy NGC 7814. Counts of objects are made to V = 24.5 and reach at least the peak of the globular-cluster luminosity function (GCLF). The bulge of NGC 7814 is of moderate luminosity and is highly flattened with an axial ratio of b/a = 0.48. Counts made from 0'.5-5'.0 radius in concentric rings of width 0'.5 show a clear detection of excess objects relative to the background in each annulus. Correcting for incompleteness in both magnitude and areal coverage yields a total cluster population of 498 +/- 164 within this region. We are thus confident that we have a strong detection of the globular-cluster system (GCS) of NGC 7814. Accounting for the presence of clusters that we could not detect in the inner few kpc and those that might lie outside our survey area would likely increase the total population by a factor of 2. At our assumed distance of (m - M) = 30.48, the specific frequency (S) of globulars is 7.6 +/- 3.2. The intrinsic GCLF for NGC 7814 is very poorly determined from these data but may indicate a distance 1 mag further away, in which case S would be 5.2 +/- 2.2. These values of S are typical for elliptical galaxies but are rather high compared to those of spirals. The radial distribution of globular-cluster candidates does not fall off as fast as the halo light. Excess counts in a field not centered on the minor axis can only be reconciled with the rest of the data if the GCS of NGC 7814 is highly flattened.
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页码:1220 / 1229
页数:10
相关论文
共 36 条
[1]   A DISTANCE SCALE FROM THE INFRARED MAGNITUDE/H-I VELOCITY-WIDTH RELATION .5. DISTANCE MODULI TO 10 GALAXY CLUSTERS, AND POSITIVE DETECTION OF BULK SUPERCLUSTER MOTION TOWARD THE MICROWAVE ANISOTROPY [J].
AARONSON, M ;
BOTHUN, G ;
MOULD, J ;
HUCHRA, J ;
SCHOMMER, RA ;
CORNELL, ME .
ASTROPHYSICAL JOURNAL, 1986, 302 (02) :536-563
[2]   A CATALOG OF INFRARED MAGNITUDES AND H-I-VELOCITY WIDTHS FOR NEARBY GALAXIES [J].
AARONSON, M ;
HUCHRA, J ;
MOULD, JR ;
TULLY, RB ;
FISHER, JR ;
VANWOERDEN, H ;
GOSS, WM ;
CHAMARAUX, P ;
MEBOLD, U ;
SIEGMAN, B ;
BERRIMAN, G ;
PERSSON, SE .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1982, 50 (02) :241-262
[3]   COLOR DISTRIBUTIONS IN EARLY-TYPE GALAXIES .2. 8 ELLIPTICALS IN THE VIRGO CLUSTER [J].
BOROSON, TA ;
THOMPSON, IB .
ASTRONOMICAL JOURNAL, 1987, 93 (01) :33-52
[4]   THE MEAN AGES OF S0 DISKS - EVIDENCE FOR STAR FORMATION 5 GIGAYEARS AGO [J].
BOTHUN, GD ;
GREGG, MD .
ASTROPHYSICAL JOURNAL, 1990, 350 (01) :73-88
[5]   THE EVOLUTION OF DISK GALAXIES AND THE S0 PROBLEM, REVISITED [J].
BOTHUN, GD .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 1982, 50 (01) :39-54
[6]  
BOTHUN GD, 1992, AJ, V104, P103
[7]   THE GLOBULAR-CLUSTER SYSTEM OF NGC-4594 (THE SOMBRERO) [J].
BRIDGES, TJ ;
HANES, DA .
ASTRONOMICAL JOURNAL, 1992, 103 (03) :800-&
[8]   THE GLOBULAR-CLUSTER SYSTEM OF THE EDGE-ON SB GALAXY NGC 5170 [J].
FISCHER, P ;
HESSER, JE ;
HARRIS, HC ;
BOTHUN, GD .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 1990, 102 (647) :5-25
[9]   GLOBULAR-CLUSTERS AS EXTRAGALACTIC DISTANCE INDICATORS - MAXIMUM-LIKELIHOOD METHODS [J].
HANES, DA ;
WHITTAKER, DG .
ASTRONOMICAL JOURNAL, 1987, 94 (04) :906-916
[10]   GLOBULAR-CLUSTERS IN GALAXIES BEYOND THE LOCAL GROUP .7. THE SO GALAXY NGC-3115 [J].
HANES, DA ;
HARRIS, WE .
ASTROPHYSICAL JOURNAL, 1986, 304 (02) :599-&