We describe 2DPHOT, a general purpose analysis environment for source detection and analysis in deep wide-field images. 2DPHOT is an automated tool to obtain both integrated and surface photometry of galaxies in an image, to perform reliable star-galaxy separation with accurate estimates of contamination at faint flux levels, and to estimate completeness of the image catalog. We describe the analysis strategy on which 2DPHOT is based, and provide a detailed description of the different algorithms implemented in the package. This new environment is intended as a dedicated tool to process the wealth of data from wide-field imaging surveys. To this end, the package is complemented by 2DGUI, an environment that allows multiple processing of data using a range of computing architectures.Comment: Accepted to PAS

SkyServer is the primary catalog data portal of the Sloan Digital Sky Survey that makes multiple terabytes of astronomy data available to the world. Here, the process is described of collecting and analyzing the complete record of more than 10 years of Web hits and SQL queries to SkyServer.

Studies of the Sun and the Earth’s atmosphere and climate consider solar variability as an important driver, and its constant monitoring is essential for climate models. Solar total and spectral irradiance are among the main relevant parameters. Physical semi-empirical and empirical models have been developed and made available, and they are crucial for the reconstruction of irradiance during periods of data failure or their absence. However, ionospheric and climate models would also benefit from solar irradiance prediction through prior knowledge of irradiance values hours or days ahead. This paper presents a neural network-based approach, which uses images of the solar photosphere to extract sunspot and active region information and thus generate inputs for recurrent neural networks to perform the irradiance prediction. Experiments were performed with two recurrent neural network architectures for short- and long-term predictions of total and spectral solar irradiance at three wavelengths. The results show good quality of prediction for total solar irradiance (TSI) and motivate further effort in improving the prediction of each type of irradiance considered in this work. The results obtained for spectral solar irradiance (SSI) point out that photosphere images do not have the same influence on the prediction of all wavelengths tested but encourage the bet on new spectral lines prediction.

A comprehensive analysis of 10 years of Web and SQL traffic on SkyServer-the online portal to the multiterabyte Sloan Digital Sky Survey archive--shows the impressive reach of the SDSS to the research community and the public, and provides insight into how methods of e-science are being taken up by the scientific community.