Cosmology

Abstract:

We analyse the first publicly released deep field of the UK Infrared Deep Sky Survey (UKIDSS) Deep eXtragalactic Survey to identify candidate galaxy overdensities at z ∼ 1 across ∼1 deg2 in the ELAIS-N1 field. Using I - K, J - K and K - 3.6 μm colours, we identify and spectroscopically follow up five candidate structures with Gemini/Gemini Multi-Object Spectrograph and confirm that they are all true overdensities with between five and 19 members each. Surprisingly, all five structures lie in a narrow redshift range at z = 0.89 ± 0.01, although they are spread across 30 Mpc on the sky. We also find a more distant overdensity at z = 1.09 in one of the spectroscopic survey regions. These five overdense regions lying in a narrow redshift range indicate the presence of a supercluster in this field and by comparing with mock cluster catalogues from N-body simulations we discuss the likely properties of this structure. Overall, we show that the properties of this supercluster are similar to the well-studied Shapley and Hercules superclusters at lower redshift. © 2007 RAS.

Abstract:

WFSPEC is a multi-integral field spectrograph instrument concept combining local AO correction over a wide field of view. This local correction is achieved by a multi object adaptive optics system integrated into the instrument. Instrument concept, development and preliminary results on performance simulations are discussed.

Abstract:

WFSPEC is a multi-integral field spectrograph instrument concept combining local AO correction over a wide field of view. This local correction is achieved by a multi object adaptive optics system integrated into the instrument. Instrument concept, development and preliminary results on performance simulations are discussed. © 2007 Optical Society of America.

Abstract:

We investigate a model of the coevolution of black holes and dark matter halos. The evolution of dark matter halos is based on the Press-Schechter theory. Assuming a simple relation between dark matter halos and supermassive black holes enables us to reproduce both the observed evolving hard X-ray luminosity function and the X-ray background.