The decade of galaxy formation: pitfalls in the path ahead

At the turn of the decade we arguably move from the era of precision cosmology to the era of galaxy formation. One approach to this problem will be via the construction of comprehensive galaxy samples. In this review I take the opportunity to highlight a number of challenges which must be overcome before we can use such data to construct a robust empirical blueprint of galaxy evolution. The issues briefly highlighted here are: the Hubble tuning fork versus galaxy components, the hierarchy of structure, the accuracy of structural decompositions, galaxy photometry, incompleteness, cosmic variance, photometric versus spectroscopic redshifts, wavelength bias, dust attenuation, and the disconnect with theory. These concerns essentially form one of the key motivations of the GAMA survey which, as one of its goals, will establish a complete comprehensive kpc-resolution 3D multi-wavelength (UV-Opt-IR-Radio) database of 250k galaxy systems to z <0.5.Comment: Review paper (12 pages, 11 figures) in "Hunting for the Dark: The Hidden Side of Galaxy Formation", Malta, 19-23 Oct. 2009, eds. V.P.Debattista & C.C.Popescu, AIP Conf. Ser., in pres

The Ccontribution of normal, dim and dwarf galaxies to the local luminosity density

From the Hubble Deep Field catalog presented in Driver et al. (1998) we derive the local (0.3 < z < 0.5) Bivariate Brightness Distribution (BBD) of field galaxies within a 326 Mpc**3 Volume-Limited sample. The sample contains 47 galaxies which uniformally sample the underlying galaxy population within the specified redshift, magnitude and surface brightness limits (0.3 < z < 0.5, -21.3 < M_{B} < -13.7 mags, 18.0 < mu_{B} < 24.55 mags/sq arcsec). We conclude: (i) A luminosity-surface brightness relation exists for both the field and cluster galaxy populations, M_{B} ~ 1.5 mu_{e} - 50, (ii) Luminous low surface brightness galaxies account for <10% of the L* population, (iii) Low luminosity low surface brightness galaxies outnumber Hubble types by a factor of ~ 1.4, however their space density is NOT sufficient to explain the faint blue excess either by themselves or as faded remnants. In terms of the local luminosity density and galaxy dynamical mass budget, normal galaxies (i.e. Hubble tuning fork) contribute 88% and 72% respectively. This compares to 7% and 12% for dim galaxies and 5% and 16% for dwarf galaxies (within the above specified limits).Comment: Accepted for publication in Astrophysical Journal Letters. Nine pages and two figure

How to get unlimited observing time on a 4 metre telescope

As the astronomical community moves ever more towards fewer and larger telescopes it is not just desirable but essential to make the maximum possible use of these new facilities. The Hitchhiker parallel CCD camera has been specially designed to increase the scientific output of a large telescope by imaging the off-axis field of view. The large data set collected by this instrument consists of deep CCD multicolor data of the distant Universe and is extremely well suited to the study of faint galaxies and their evolution, as well as other areas. The instrument's design and some of its projects are briefly discussed below and demonstrates the scientific value such instruments could have if incorporated on all new telescopes