S3SEX Overview
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Please note that all data obtained using the S-Cubed SEX database prior to 29 November 2010 was missing Column 21 (250 micron flux density). The bug has now been fixed and the 250 micron flux densities should now appear in the output.

Overview

S3-SEX is a simulation of extragalactic radio continuum sources in a sky area of 20×20 deg2, out to a cosmological redshift of z = 20. The simulation method is "semi-empirical", meaning that the sources were drawn from observed (or extrapolated) luminosity functions and grafted onto an underlying dark matter density field with biases which reflect their measured large-scale clustering. This approach puts an emphasis on modelling the large-scale cosmological distribution of radio sources rather than the internal structure of individual galaxies. For each source, the database gives the radio fluxes at observer frequencies of 151 MHz, 610 MHz, 1.4 GHz, 4.86 GHz and 18 GHz, down to flux density limits of 10 nJy. (Ref.: Wilman et al., 2008).

In 2010 the S3-SEX Galaxies table was updated to include Infrared flux densities. These were extrapolated from radio continuum frequencies via a 'semi-empirical' philosophy similar to that used in the original simulation. We have added flux densities at wavelengths of 24, 70, 100, 160, 250, 350, 450, 500, 850 and 1200 microns to the Galaxies table. A full description of the infrared portion of the simulation can be found in Wilman et al. 2010 .

Source types

Sources are separated in 5 distinct types:

  • Radio-quiet AGN [1 core] : 36,132,566 sources
  • Radio-loud AGN of the FRI class [1 core + 2 lobes] : 23,853,132 sources
  • Radio-loud AGN of the FRII class [1 core + 2 lobes + 2 hot-spots] : 2,345 sources
  • Quiescent star-forming galaxies [1 disk] : 207,814,522 sources
  • Starbursting galaxies [1 disk] : 7,267,382 sources

Source morphologies

Sources are constructed from point source [core and hot-spots] and elliptical [disks and lobes] sub-components.

Continuum information

The continuum emission is given by flux densities at five reference frequencies : 151 MHz, 610 MHz, 1.4 GHz, 4.86 GHz and 18 GHz. Only those sources of which at least one subcomponent has a flux density over 10 nJy at one or more of these five frequencies are kept.

Spatial distribution

The simulated sources are drawn from observed (or extrapolated) luminosity functions and grafted onto an underlying dark matter density field with biases which reflect their large-scale clustering.

Database organisation

The database is made of a cluster table, and a source table, whose structures are described here.

A detailed description of the simulation can be found in Wilman et al. 2008.