Dynamics of the Cluster of Galaxies A3558
(Hugo Capelato)

In a previous work we have shown  that the central region of this cluster is
dynamically complex, being dominated by various clumps of galaxies, to one of
which belongs the cD galaxy.  This has prompted us to suggest that the cD is
really dynamically bounded to this clump and that the cluster is still
unrelaxed and dynamically young. We have completed a survey of galaxy counts in
this cluster and found an excess population of faint galaxies in the
neighbourhood of the cD galaxy. Here we propose to observe this population in
order to verify i) if it really belongs to the cluster and, if yes, ii) how is
its dynamics related to the presence of the cD and iii) how does its luminosity
function compare with that of the other non-cD clumps.

Required minimum field of view: 20 arcminute
Required psf: 1 arcsecond is adequate
Signal/Noise required: 20 or better
Typical exposure time for this S/N and lunar phase: 3 hours (19 < B < 21, 7A 
					    resolution)/Argus field;
						    5-6 Argus fields; dark.
Required instruments: Argus Fiber Feed Spectrograph + Blue Air Schmidt Camera +
	      Reticon CCD
Can this program execute in a queue: yes
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Loose structures embedding Compact Groups of Galaxies
(Hugo Capelato)

Photometric and spectroscopic studies of fields around centered Compact Groups
of Galaxies (CGG) have demonstrated that a considerable fraction of these
systems are dynamically related to a population of faint galaxies of unknown
extension which, in some few cases for which redshifts surveys
existed, were identified to loose groups. Here we propose to use ARGUS to
make surveys of galaxies redshifts in fields of about 1 squared degree around
a selected sample of CGG's in order to establish the dynamical nature of these
structures. The determination of the morphology of this faint galaxy population
with comparable accuracy as the brighter ones is highly desirable so that
an accompanying subproject would deal with good quality imaging of these
same fields.

Set up requirements: same as above for A3558 project +  medium (better
			   than 1 arcsecond) resolution imaging in the visible.
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IR spectroscopical mapping of central regions of Elliptical Galaxies
(Hugo Capelato)

Recent work on numerical simulations as well as some recent derivations of
the Fundamental Plane of elliptical galaxies in the IR, suggest that the
non-homology of the central velocity field of these systems may be at
the origin of these correlations. We propose a detailed IR spectroscopical
mapping of the central regions (r < 0.5r_e) of a sample of these galaxies in
order to disprove or not the central non-homology hypothesis. Moreover, a
detailed knowledge of the  projected velocity distribution of these 
systems may allow access to important parameters (e.g the anisotopy parameter
and its variation with radius) governing the dynamics of these galaxies.


Required minimum field of view: 5 arcminute is adequate
Required psf: 0.2 arcsec
Signal/Noise required: > 50
Typical exposure time for this S/N and lunar phase: 3 hours/object;dark/mid-dark
Required instruments: medium resolution IR spectroscopy (5A)
Can this program execute in a queue: yes (but one complete mapping per
						 queue input desirable...) 
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