TY - JOUR
T1 - The ACS fornax cluster survey. VIII. the luminosity function of globular clusters in Virgo and fornax early-type galaxies and its use as a distance indicator
AU - Villegas, Daniela
AU - Jordn, Andrés
AU - Peng, Eric W.
AU - Blakeslee, John P.
AU - Cté, Patrick
AU - Ferrarese, Laura
AU - Kissler-Patig, Markus
AU - Mei, Simona
AU - Infante, Leopoldo
AU - Tonry, John L.
AU - West, Michael J.
PY - 2010
Y1 - 2010
N2 - We use a highly homogeneous set of data from 132 early-type galaxies in the Virgo and Fornax clusters in order to study the properties of the globular cluster luminosity function (GCLF). The globular cluster system of each galaxy was studied using a maximum likelihood approach to model the intrinsic GCLF after accounting for contamination and completeness effects. The results presented here update our Virgo measurements and confirm our previous results showing a tight correlation between the dispersion of the GCLF and the absolute magnitude of the parent galaxy. Regarding the use of the GCLF as a standard candle, we have found that the relative distance modulus between the Virgo and Fornax clusters is systematically lower than the one derived by other distance estimators, and in particular, it is 0.22mag lower than the value derived from surface brightness fluctuation measurements performed on the same data. From numerical simulations aimed at reproducing the observed dispersion of the value of the turnover magnitude in each galaxy cluster we estimate an intrinsic dispersion on this parameter of 0.21mag and 0.15mag for Virgo and Fornax, respectively. All in all, our study shows that the GCLF properties vary systematically with galaxy mass showing no evidence for a dichotomy between giant and dwarf early-type galaxies. These properties may be influenced by the cluster environment as suggested by cosmological simulations.
AB - We use a highly homogeneous set of data from 132 early-type galaxies in the Virgo and Fornax clusters in order to study the properties of the globular cluster luminosity function (GCLF). The globular cluster system of each galaxy was studied using a maximum likelihood approach to model the intrinsic GCLF after accounting for contamination and completeness effects. The results presented here update our Virgo measurements and confirm our previous results showing a tight correlation between the dispersion of the GCLF and the absolute magnitude of the parent galaxy. Regarding the use of the GCLF as a standard candle, we have found that the relative distance modulus between the Virgo and Fornax clusters is systematically lower than the one derived by other distance estimators, and in particular, it is 0.22mag lower than the value derived from surface brightness fluctuation measurements performed on the same data. From numerical simulations aimed at reproducing the observed dispersion of the value of the turnover magnitude in each galaxy cluster we estimate an intrinsic dispersion on this parameter of 0.21mag and 0.15mag for Virgo and Fornax, respectively. All in all, our study shows that the GCLF properties vary systematically with galaxy mass showing no evidence for a dichotomy between giant and dwarf early-type galaxies. These properties may be influenced by the cluster environment as suggested by cosmological simulations.
KW - galaxies: elliptical and lenticular, cD
KW - galaxies: star clusters: general
KW - globular clusters: general
UR - http://www.scopus.com/inward/record.url?scp=77953879495&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/717/2/603
DO - 10.1088/0004-637X/717/2/603
M3 - Article
AN - SCOPUS:77953879495
SN - 0004-637X
VL - 717
SP - 603
EP - 616
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
ER -