Broadband Photometric Reverberation Mapping Analysis on SDSS-RM and Stripe 82 Quasars

摘要

We modified the broadband photometric reverberation mapping (PRM) code,JAVELIN, and tested the availability to get broad line region (BLR) time delaysthat are consistent with the spectroscopic reverberation mapping (SRM) projectSDSS-RM. The broadband light curves of SDSS-RM quasars produced by convolutionwith the system trans- mission curves were used in the test. We found thatunder similar sampling conditions (evenly and frequently sampled), the keyfactor determining whether the broadband PRM code can yield lags consistentwith the SRM project is the flux ratio of the broad emission line to thereference continuum, which is in line with the previous findings. We furtherfound a critical line-to-continuum flux ratio, about 6%, above which the meanof the ratios between the lags from PRM and SRM becomes closer to unity, andthe scatter is pronouncedly reduced. We also tested our code on a subset ofSDSS Stripe 82 quasars, and found that our program tends to give biased lagestimations due to the observation gaps when the R-L relation prior in MarkovChain Monte Carlo (MCMC) is discarded. The performance of the damped randomwalk (DRW) model and the power-law (PL) structure function model on broadbandPRM were compared. We found that given both SDSS-RM-like or Stripe 82-likelight curves, the DRW model performs better in carrying out broadband PRM thanthe PL model.