We report the discovery of a dwarf Seyfert 1 active galactic nucleus ( AGN ) with a candidate intermediate-mass black hole hosted by the dwarf galaxy SDSS J160531.84+174826.1 at z = 0.032 .
A broad component of the H \alpha line with FWHM=781km s ^ { -1 } is detected in its optical spectrum , and a bright , point-like nucleus is evident from a HST imaging observation .
Non-thermal X-ray emission is also detected from the nucleus .
The black hole mass , as estimated from the luminosity and width of the broad H \alpha component , is about 7 \times 10 ^ { 4 } M _ { \odot } .
The host galaxy appears to be a disk galaxy with a boxy bulge or nuclear bar ; with an absolute magnitude of M _ { R } = -17.8 , it is among the least luminous host galaxies ever identified for a Seyfert 1 .