zFinder is a spectral analysis software developed to measure the redshift (z) value of quasar spectra. The code compares the observed spectrum with a quasar template across the entire wavelength range, evaluating both the continuum structure and strong emission lines simultaneously. Rather than relying solely on the classical cross-correlation approach, it aims to achieve a more reliable and accurate z measurement by utilizing additional statistical fitting parameters.
(Kaçan et al., 2022)
References
2022
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Determining Redshift in Quasars: zFinder
Enes Selam Kaçan, Seyit Hökelek, and Nurten Filiz Ak
Turkish Journal of Astronomy and Astrophysics, Dec 2022
This study presents the algorithm and the test results for the zFinder pipeline code that is developed to measure the redshift (z) of the quasar spectra. The methodological approach of the zFinder code considers both the and Spearman parameters to define the accordance parameter where majority of the existing studies adopt the cross-correlation. The approach of comparing the entire observed spectra with a quasar template increases the precision of the measured z value by examining both the continuum and the strong lines on each spectra. We test the "zFinder" results for 150 quasars selected from SDSS DR16 quasar catalog of which z values are measured by spec1d pipeline of SDSS. We show that the z values are in a general agreement with and the average difference between zFinder and is "0.0018". There is one quasar spectra with measurements of "z=6.6.48" from "spec1d" and "z = 0.38" from "zFinder". Further investigations of the spectra showed that the "zFinder" gives the more accurate value of "z" and the "spec1d" misclassified the strong emission lines of the quasar.