We present a high-resolution ( R \approx 16 , 000 ) spectrum and a narrow-band image centered on the [ Ne ii ] 12.8 \mu m line of the central kpc region of the starburst/Seyfert 2 galaxy NGC 7582 .
The galaxy has a rotating circum-nuclear starburst disk , shown at great detail at a diffraction-limited resolution of 0 \aas@@fstack { \prime \prime } 4 ( \approx 40 pc ) .
The high spatial resolution allows us to probe the dynamics of the [ Ne ii ] gas in the nuclear regions , and to estimate the mass of the central black hole .
We construct models of gas disks rotating in the combined gravitational potential from the stellar bulge and a central black hole , and derive a black hole mass of 5.5 \times 10 ^ { 7 } M _ { \odot } with a 95 % confidence interval of [ 3.6,8.1 ] \times 10 ^ { 7 } M _ { \odot } .
The black hole mass combined with stellar velocity dispersion measurements from the literature shows that the galaxy is consistent with the local M _ { BH } - \sigma _ { * } relation .
This is the first time that a black hole mass in a galaxy except our own Milky Way system has been estimated from gas dynamics in the mid-infrared .
We show that spatially resolved mid-infrared spectroscopy may be competitive with similar techniques in the optical and near-infrared , and may prove to be important for estimating black hole masses in galaxies with strong nuclear dust obscuration .
The high spectral resolution allows us to determine the heliocentric systemic velocity of the galaxy to between 1614 and 1634 km s ^ { -1 } .
The mid-infrared image reveals several dense knots of dust-embedded star formation in the circum-nuclear disk , and we briefly discuss its morphology .