2003/10/20 by Željko Ivezić, Z. Ivezic, Ivezic, Z. +29 · 1 citation
Engineering · Mathematics · Physics and Astronomy · #Astrophysics (astro-ph) #Calibration and Measurement Techniques #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Statistical and numerical algorithms #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0310569
to be published in the Proceedings of "AGN Physics with the SDSS"
arxiv created 2003/10/20 · openalex publication_date 2003/10/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Recent claims by Ivezic et al. (2002) that the distribution of the radio-to-optical flux ratio, R, for quasars is bimodal (the so-called quasar radio dichotomy) were questioned on statistical grounds by Cirasuolo et al. (2003). We apply the approach suggested by Cirasuolo et al. to a sample of \~10,000 objects detected by SDSS and FIRST, and find support for the quasar radio dichotomy. The discrepancy between the claims by Cirasuolo et al. and the results presented here is most likely because 1) the ~100 times larger sample based on two homogeneous surveys that is used here allows a direct determination of the R distribution, rather than relying on indirect inferences based on Monte Carlo simulations of several heterogeneous surveys 2) the accurate SDSS colors and redshift information allow robust determination of the K-correction for R, which, if unaccounted for, introduces significant scatter that masks the intrinsic properties of the quasar R distribution.