We present an integral field spectroscopic study of the central 2 \times 2 kpc ^ { 2 } of the blue compact dwarf galaxy Mrk 409 , observed with the Potsdam MultiAperture Spectrophotometer .
This study focuses on the morphology , two-dimensional chemical abundance pattern , excitation properties and kinematics of the ionized interstellar medium in the starburst component .
We also investigate the nature of the extended ring of ionized gas emission surrounding the bright nuclear starburst region of Mrk 409 .
PMAS spectra of selected regions along the ring , interpreted with evolutionary and population synthesis models , indicate that their ionized emission is mainly due to a young stellar population with a total mass of \sim 1.5 \times 10 ^ { 6 } M _ { \sun } , which started forming almost coevally \sim 10 Myr ago .
This stellar component is likely confined to the collisional interface of a spherically expanding , starburst-driven super-bubble with denser , swept-up ambient gas , \sim 600 pc away from the central starburst nucleus .
The spectroscopic properties of the latter imply a large extinction ( \mbox { $C _ { \mathrm { H } \beta } $ } > 0.9 ) , and the presence of an additional non-thermal ionization source , most likely a low-luminosity Active Galactic Nucleus .
Mrk 409 shows a relatively large oxygen abundance ( 12 + \log ( \mathrm { O / H } ) \sim 8.4 ) and no chemical abundance gradients out to R \sim 600 pc .
The ionized gas kinematics displays an overall regular rotation on a northwest-southwest axis , with a maximum velocity of 60 km s ^ { -1 } ; the total mass inside the star-forming ring is about 1.4 \times 10 ^ { 9 } M _ { \sun } .