Astronomy and Astrophysics – Astrophysics
Scientific paper
2007-03-20
Astrophys.J.662:940-951,2007
Astronomy and Astrophysics
Astrophysics
ApJ accepted
Scientific paper
10.1086/517984
Taking advantage of the exceptional capabilities of ACS on board of HST, we derive Surface Brightness Fluctuation (SBF) measurements in the B and I bands from images of six elliptical galaxies with $1500 \leq cz \leq 3500$. Given the low S/N ratio of the SBF signal in the blue band images, the reliability of the measurements is verified both with numerical simulations and experimental data tests. This paper presents the first published B- and I-band SBF measurements for distant ($\geq$ 20 Mpc) galaxies, essential for the comparisons of the models to observations of normal ellipticals. By comparing I-band data with our new Simple Stellar Population (SSP) models we find an excellent agreement and we confirm that I-band SBF magnitudes are mainly sensitive to the metallicity of the dominant stellar component in the galaxy, and are not strongly affected by the contribution of possible secondary stellar components. As a consequence I-band fluctuations magnitudes are ideal for distance studies. On the other hand, we show that standard SSP models do not reproduce the B-band SBF magnitudes of red ($(B-I)_0 \gsim 2.1$) galaxies in our sample. We explore the capability of two non--canonical models in properly reproducing the high sensitivity of B SBF to the presence of even small fractions of bright, hot stars (metal poor stars, hot evolved stars, etc.). The disagreement is solved both by taking into account hot (Post--AGB) stars in SSP models and/or by adopting Composite Stellar Population models. Finally, we suggest a limit value of the S/N for the B-band SBF signal required to carry out a detailed study of stellar population properties based on this technique.
Blakeslee John P.
Brocato Enzo
Cantiello Michele
Capaccioli Massimo
Raimondo Gabriella
No associations
LandOfFree
Detection of Surface Brightness Fluctuations in Elliptical Galaxies imaged with the Advanced Camera for Surveys. B- and I-band measurements does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Detection of Surface Brightness Fluctuations in Elliptical Galaxies imaged with the Advanced Camera for Surveys. B- and I-band measurements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Detection of Surface Brightness Fluctuations in Elliptical Galaxies imaged with the Advanced Camera for Surveys. B- and I-band measurements will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-381865