We investigate the effects of extended multi-year light curves (9-year photometry and 5-year spectroscopy) on the detection of time lags between the continuum variability and broad-line response of quasars at z>~1.5, and compare with the results using 4-year photometry+spectroscopy presented in a companion paper. We demonstrate the benefits of the extended light curves in three cases: (1) lags that are too long to be detected by the shorter-duration data but can be detected with the extended data; (2) lags that are recovered by the extended light curves but missed in the shorter-duration data due to insufficient light curve quality; and (3) lags for different broad line species in the same object. These examples demonstrate the importance of long-term monitoring for reverberation mapping to detect lags for luminous quasars at high-redshift, and the expected performance of the final dataset from the Sloan Digital Sky Survey Reverberation Mapping project that will have 11-year photometric and 7-year spectroscopic baselines.
@article{arxiv.1908.00027,
title = {The Sloan Digital Sky Survey Reverberation Mapping Project: Improving Lag Detection with an Extended Multi-Year Baseline},
author = {Yue Shen and C. J. Grier and Keith Horne and W. N. Brandt and J. R. Trump and P. B. Hall and K. Kinemuchi and David Starkey and D. P. Schneider and Luis C. Ho and Y. Homayouni and Jennifer Li and Ian D. McGreer and B. M. Peterson and Dmitry Bizyaev and Yuguang Chen and K. S. Dawson and Sarah Eftekharzadeh and P. J. Green and Yucheng Guo and Siyao Jia and Linhua Jiang and Jean-Paul Kneib and Feng Li and Zefeng Li and Jundan Nie and Audrey Oravetz and Daniel Oravetz and Kaike Pan and Patrick Petitjean and Kara Ponder and Jesse Rogerson and M. Vivek and Tianmen Zhang and Hu Zou},
journal= {arXiv preprint arXiv:1908.00027},
year = {2019}
}