DEEP OPTICAL GALAXY COUNTS WITH THE KECK-TELESCOPE

被引:156
作者
SMAIL, I [1 ]
HOGG, DW [1 ]
YAN, L [1 ]
COHEN, JG [1 ]
机构
[1] CALTECH,PALOMAR OBSERV,PASADENA,CA 91125
基金
美国国家科学基金会;
关键词
COSMOLOGY; OBSERVATIONS; GALAXIES; EVOLUTION; PHOTOMETRY;
D O I
10.1086/309647
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present faint galaxy counts from deep VRI images obtained with the Keck Telescope. These images reach R similar to 27 in median seeing FWHM similar to 0 ''.5-0 ''.6, and we detect a integrated galaxy number density of 7 x 10(5) deg(-2), equivalent to 3 x 10(10) galaxies in the observable universe. In addition we present median galaxy colors as a function of magnitude; bluing trends are visible in all colors to R similar to 24.5. Fainter than R similar to 24.5, however, the typical V - R color becomes redder again, V - I remains constant, and R - I becomes yet bluer. These trends are consistent with the VRI count slopes, implying a decrease in the V slope at the faintest levels, which our data support. Taking advantage of our good seeing we also present median half-light radii for faint galaxies; these show a steady decline at fainter magnitudes, leading to an intrinsic half-light radius of similar to 0 ''.2 for a typical R similar to 26 galaxy. Irrespective of the redshift distribution, the extremely high galaxy surface densities and their small intrinsic sizes are consistent with a scenario in which the majority of the very faint field population are dwarf galaxies or subgalactic units.
引用
收藏
页码:L105 / L108
页数:4
相关论文
共 17 条
[1]  
BERTIN E, 1994, SEXTRACTOR MANUAL
[2]  
COWIE LL, 1995, APJ, V434, P114
[3]   DEEP GALAXY COUNTS IN THE K-BAND WITH THE KECK TELESCOPE [J].
DJORGOVSKI, S ;
SOIFER, BT ;
PAHRE, MA ;
LARKIN, JE ;
SMITH, JD ;
NEUGEBAUER, G ;
SMAIL, I ;
MATTHEWS, K ;
HOGG, DW ;
BLANDFORD, RD ;
COHEN, J ;
HARRISON, W ;
NELSON, J .
ASTROPHYSICAL JOURNAL, 1995, 438 (01) :L13-L14
[4]   DIRECT CONSTRUCTION OF THE GALAXY LUMINOSITY FUNCTION AS A FUNCTION OF REDSHIFT [J].
EALES, S .
ASTROPHYSICAL JOURNAL, 1993, 404 (01) :51-62
[5]  
ELLIS RS, 1995, UNPUB MNRAS
[6]   GALAXY NUMBER COUNTS FROM K=10 TO K=23 [J].
GARDNER, JP ;
COWIE, LL ;
WAINSCOAT, RJ .
ASTROPHYSICAL JOURNAL, 1993, 415 (01) :L9-L12
[7]  
KOO DC, 1992, ANNU REV ASTRON ASTR, V30, P613
[8]   UBVRI PHOTOMETRIC STANDARD STARS IN THE MAGNITUDE RANGE 11.5-LESS-THAN-V-LESS-THAN-16.0 AROUND THE CELESTIAL EQUATOR [J].
LANDOLT, AU .
ASTRONOMICAL JOURNAL, 1992, 104 (01) :340-&
[9]   A DEEP IMAGING AND SPECTROSCOPIC SURVEY OF FAINT GALAXIES [J].
LILLY, SJ ;
COWIE, LL ;
GARDNER, JP .
ASTROPHYSICAL JOURNAL, 1991, 369 (01) :79-&
[10]   THE STROMLO-APM REDSHIFT SURVEY .1. THE LUMINOSITY FUNCTION AND SPACE DENSITY OF GALAXIES [J].
LOVEDAY, J ;
PETERSON, BA ;
EFSTATHIOU, G ;
MADDOX, SJ .
ASTROPHYSICAL JOURNAL, 1992, 390 (02) :338-344