We present the results of a three years monitoring campaigns of the z = 0.024 type-1 active galactic nucleus ( AGN ) PGC50427 .
Using robotic telescopes of the Universitätssternwarte Bochum near Cerro Armazones in Chile , we monitored PGC50427 in the optical and near-infrared ( NIR ) .
Through the use of Photometric Reverberation Mapping with broad and narrow band filters , we determine the size of the broad-line emitting region by measuring the time delay between the variability of the continuum and the H \alpha emission line .
The H \alpha emission line responds to blue continuum variations with an average rest frame lag of 19.0 \pm 1.23 days .
Using single epoch spectroscopy obtained with the Southern African Large Telescope ( SALT ) we determined a broad-line H \alpha velocity width of 1020 km s ^ { -1 } and in combination with the rest frame lag and adoption a geometric scaling factor f = 5.5 , we calculate a black hole mass of M _ { BH } \sim 17 \times 10 ^ { 6 } M _ { \odot } .
Using the flux variation gradient method , we separate the host galaxy contribution from that of the AGN to calculate the rest frame 5100Å luminosity at the time of our monitoring campaign .
We measured small luminosity variations in the AGN ( \sim 10 \% ) accross the 3 years of the monitoring campaign .
The rest frame lag and the host-subtracted luminosity permit us to derive the position of PGC50427 in the BLR size – AGN luminosity diagram , which is remarkably close to the theoretically expected relation of R \propto L ^ { 0.5 } .
The simultaneous optical and NIR ( J and K _ { s } ) observations allow us to determine the size of the dust torus through the use of dust reverberation mapping method .
We find that the hot dust emission ( \sim 1800 K ) lags the optical variations with an average rest frame lag of 46.2 \pm 2.60 days .
The dust reverberation radius and the nuclear NIR luminosity permit us to derive the position of PGC50427 on the known \tau - M { V } diagram .
The simultaneus observations for the broad-line region and dust thermal emission demonstrate that the innermost dust torus is located outside the BLR in PGC50427 , supporting the unified scheme for AGNs .