18 June 2002 UT with an exposure time of 4803 s exposure. It was classified as a galaxy by the spectroscopic pipeline of the SDSS Fourth Data Release (Adelman-McCarthy et al. 2006). In the course of our systematic spectral fitting of all extragalactic objects in the SDSS, we first noted UM 625 because it showed evident broad [H$\alpha$]{} and [H$\beta$]{} emission; its inferred virial BH mass placed it in the sample of type 1 AGNs with BH masses below $2 \times 10^6$ [$M_{\odot}$]{} described by Dong et al. (2012b). The details of the spectral analysis are given in Dong et al. (2012b). Here we present a brief description of the continuum modeling and emission-line profile fitting, which are based on the MPFIT package (Markwardt 2009) that performs [$\chi^2$]{}-minimization by the Levenberg–Marquardt technique.

UM 625 has a redshift of $z=0.0250$, and its SDSS spectrum is dominated by host galaxy starlight. The median signal-to-noise (S/N) ratio in the [H$\beta$]{}–[\[O[III]{}\]]{} and [H$\alpha$]{}–[\[N[II]{}\]]{}–[\[S[II]{}\]]{} regions are 45 and 60 pixel$^{-1}$, respectively, high enough to fit accurately the continuum and emission lines. We begin by correcting the spectrum for Galactic extinction using the extinction map of Schlegel et al. (1998) and the reddening curve of Fitzpatrick 