The Very Small Array: Observations and latest results

The Very Small Array (VSA) is a unique interferometric telescope operating at 33 GHz at Tenerife. It has the ability to measure fluctuations in the CMB over a large range of angular scales by means of three main array configurations: compact, extended and super-extended. These angular scales correspond to the multipole range l = 150 - 2500. Here we present new results from further observations of the extended array (February 2002 - June 2003). We cover l-values up to l similar to 1600, thus doubling the l-range of WMAP. The resulting power spectrum in the l-range 800 - 1600 has very low noise coupled with good e-resolution (Delta l similar to 80). Furthermore, the use of independently tracking aerials along with the dedicated source subtraction baseline allows unprecedented control of systematics. The latter is essential, since discrete sources are the dominant foreground at these angular scales. These measurements over larger l-ranges are important in confirming the present cosmological paradigm and breaking degeneracies in the extraction of cosmological parameters.