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Find information, examples, FAQs and extensive descriptions of the data, curated by the survey teams.

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The Siding Spring Southern Seyfert Spectroscopic Snapshot Survey
July 1, 2021 by S. Ridolfo
March 18, 2022, 9:21 a.m. S. Ridolfo

S7 Target Selection

The S7 survey consists of 131 nearby active galaxies. It is by no means a complete survey of southern Seyfert, LINERs and other active galaxies but rather, offers a reasonably representative sample of radio-detected AGN in the nearby universe. The objects for the S7 were selected from the Véron-Cetty & Véron (2006, 2010) catalogue of active galaxies, which remains the most comprehensive compilation of active galaxies in the literature. Since, in the future, we wish to investigate the interaction of the bipolar plasma jets with the Narrow Line Region and the ISM of the host galaxy, we limited the sample to galaxies with radio flux densities high enough to allow radio aperture synthesis observations. The S7 Galaxy Survey target selection is described in further detail in Thomas et al. (2017).

We adopted the following selection criteria:

  • Declination < 10° to avoid observations being made at too great a zenith distance. At a zenith distance of 60 degrees, the atmospheric dispersion between 3500 and 7000 Å is nearly 6 arcsec, which would seriously compromise the effective field coverage.
  • Galactic latitude > |20| degrees (with a few exceptions in the case of objects known to have an associated ENLR ). This galactic latitude requirement is set to avoid excessive galactic extinction.
  • Radio flux density at 20cm > 20mJy for those targets with declination N of -40°, which have NVSS measurements, and
  • Redshift < 0.02. This criterion (D < 80 Mpc) ensures that the spatial resolution of the data is better than 400 pc per arcsec, sufficient to resolve the ENLR, and to ensure that the important diagnostic [S II] lines are still within the spectral range of the WiFeS high-resolution red grating.
July 1, 2021 by S. Ridolfo
March 18, 2022, 9:21 a.m. S. Ridolfo