Document Type


Publication Date


Publication Title

Letters of the Astrophysical Journal


Department of Physics and Astronomy


We present the first results from a detailed analysis of photometric and spectrophotometric data on the narrow-line Seyfert 1 (NLS1) galaxy Mrk 335, collected over a 120 day span in the fall of 2010. From these data we measure the lag in the He ii λ 4686 broad emission line relative to the optical continuum to be 2.7 °æ 0.6 days and the lag in the Hβλ 4861 broad emission line to be 13.9 °æ 0.9 days. Combined with the line width, the He ii lag yields a black hole mass MBH = (2. 6 °æ 0. 8) °ø 107M . This measurement is consistent with measurements made using the Hβλ 4861 line, suggesting that the He ii emission originates in the same structure as Hβ , but at a much smaller radius. This constitutes the first robust lag measurement for a high-ionization line in an NLS1 galaxy and supports a scenario in which the He ii emission originates from gas in virial motion rather than outflow.



Original Citation

C. J. Grier et al 2012 ApJL 744 L4