南方基地知识库

We propose a method for\ the flux calibration of reverberation mapping spectra, based on accurate measurement of [O III] lambda 5007 emission by spectral fitting. Our method can achieve better accuracy than the traditional method of Groningen & Wanders, allowing reverberation mapping measurements for objects with variability amplitudes as low as similar to 5%. As a demonstration, we reanalyze the data of the Seyfert 1 galaxy MCG-6-30-15, taken from the 2008 campaign of the Lick active galactic nucleus monitoring project, which previously failed to obtain a time lag for this weakly variable object, owing to a relatively large flux calibration uncertainty. We detect a statistically significant rest-frame time lag of 6.38(-2.69)(+3.07) days between the H beta and V-band light curves. Combining this lag with FWHM(H beta) = 1933 +/- 81 km s(-1) and a virial coefficient of f = 0.7, we derive a virial black hole mass of 3.26(-1.40)(+1.59) x 10(6) M circle dot, which agrees well with previous estimates by other methods.