GMOS SV program 59

	Status: in preparation Data link: not yet available Assessment: not yet available

Title:	Stellar populations in dE/dS0 galaxies
Modes:	Imaging (for mask preparation) Longslit spectroscopy Multi-object spectroscopy
Additional instrument verification:	Data reduction pipeline for imaging data, longslit data and MOS data; mask preparation software; use of tilted slits.
Telescope verification:	Acquisition and guiding with GMOS for tested modes. Stability of guiding over long periods of time and large hour angles.
Proposed observing sequence:	Imaging: 4 dithered observations in order to cover the gaps between the CCDs and clean the combined images for bad pixels and cosmic-ray-events. Longslit: 15-30 min per setup. MOS: 15-60 min per mask.
OT program file:	Not yet available
Science background:	The aim of the project is to gain knowledge about the stellar populations in faint E and S0 g alaxies; their mean ages and metal content. We propose to measure velocity dispersions and absorption line strengths for a sample of these galaxies in nearby rich clusters. The data will be used to establish the Fundamental Plane for these faint galaxies, study the M/L rations; estimate mean ages and metal content. This information can contain current models for galaxy evolution.
Target(s):	Galaxies in a nearby rich galaxy cluster
	Object	RA (J2000)	Dec (J2000)	z
	Perseus cluster	03:15	41:20	0.018
	Coma cluster	12:57	28:16	0.024
Observing condition constraints:	image quality: 80%-ile sky transparency (clouds): 70%-ile sky transparency (water vapour): Any sky background: 80%-ile max air mass: 2.0
Instrument configuration:	Imaging: r', i', CCD binned 2x2 MOS or Longslit: B600, central wavelength=600nm, 0.5" slitlets, CCD binned 2x2
Observing time requirements:	Imaging: 4x3 min Longslit: 15-30min exposures on brighter galaxies, B=16.5-18 mag MOS: 2x30min per masks containing fainter galaxies, B=19.5 mag
SV team member(s) responsible for assessment:	Inger Jørgensen

Last update October 12, 2001; Inger Jørgensen