Search

In this paper we have evaluated the amount of available telescope time at four interesting sites for astronomical instrumentation. We use the GOES 12 data for years 2008 and 2009. We use a homogeneous methodology presented in several previous papers to classify the nights as clear (completely cloud-free), mixed (partially cloud-covered) or covered. Additionally, for the clear nights we have evaluated the number of satellite-stable nights, corresponding to the number of ground-based photometric nights, and the clear nights, corresponding to the spectroscopic nights. We have applied this model to two sites in the Northern Hemisphere (San Pedro Martir (SPM), Mexico and Izaña, Canary Islands) and to two sites in the Southern Hemisphere (El Leoncito, Argentina and San Antonio de Los Cobres (SAC), Argentina). We have obtained, for the two years considered, mean percentages of cloud-free nights of 68.6 per cent at Izaña, 76.0 per cent at SPM, 70.6 per cent at Leoncito and 70.0 per cent at SAC. We have evaluated, amongst the cloud-free nights, a proportion of stable nights of 62.6 per cent at Izaña, 69.6 per cent at SPM, 64.9 per cent at Leoncito and 59.7 per cent at SAC. [ABSTRACT FROM PUBLISHER]

ABSTRACT Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources are classes of compact, powerful, extragalactic objects. These sources are thought to be the earliest stages in the evolution of radio galaxies, capturing the ignition (or, in some cases, re-ignition) of the active galactic nucleus. As well as serving as probes of the early stages of large-scale radio sources, these sources are good, stable, amplitude calibrators for radio telescopes. We present an unbiased flux density limited ( >1.5 Jy at 2.7 GHz) catalogue of these objects in the Southern hemisphere, including tabulated data, radio spectra, and where available, optical images and measurements. The catalogue contains 26 sources, consisting of two new candidates and 15 known CSS sources, and nine known GPS sources. We present new Australia Telescope Compact Array (ATCA) data on 10 of these 26 sources, and data on a further 42 sources which were excluded from our final sample. This bright sample will serve as a reference sample for comparison with subsequent faint (mJy level) samples of CSS and GPS candidates currently being compiled. [ABSTRACT FROM AUTHOR]