2013ApJ...773...24R

We present results of a reverberation mapping (RM) campaign on the low black hole mass narrow-line Seyfert 1 (NLS1) galaxy SDSS J113913.91+335551.1 (hereafter SL01). Using the Hβ measurements, we find a time lag τ = 12.5 _–11^+0.5 days and a broad-line velocity width of 1450 km/s which implies a black hole mass of 3.8_–2.8^+0.6 x 10⁶ M_☉. To further bolster our time lag results, we employ a secondary method based on the multivariate correlation function as described in Chelouche & Zucker, in which case we obtain consistent lags for the Balmer lines, yet without the need to spectrally deconvolve line from continuum emission processes. Given SL01's luminosity (L_bol~ 7x10⁴³ erg/s), we estimate an Eddington ratio (L_bol/L_Edd) of ∼0.18. This fairly low-mass determination and rather high L_bol/L_Edd is consistent with the current paradigm that the nuclei of NLS1 galaxies host small black holes (as low as 10⁶ M_☉) with high accretion rates. SL01 is one of only a few NLS1s to date with robust RM results.