Mapping the star formation history of Mrk 86 - I. Data and models

We have obtained optical (BVR, [O III]lambda 5007 Angstrom and H alpha), ne ar infrared (JHK) imaging and long-slit optical spectroscopy for the Blue C ompact Dwarf galaxy Mrk 86 (NGC 2537). In this paper, the first of two, we present optical-near-infrared colors and emission-line fluxes for the curre ntly star-forming regions, intermediate aged starburst and underlying stell ar population. We also describe the evolutionary synthesis models used in P aper II. The R and H alpha luminosity distributions of the galaxy star-forming regio ns show maxima at M-R = -9.5(m) and L-H alpha = 10(37.3) ergs(-l). The unde rlying stellar population shows an exponential surface brigthness profile w ith central value, mu(E),(0) = 21.5 mag arcsec(-2), and scale, alpha = 0.88 kpc, both measured in the R-band image. In the galaxy outer regions, domin ated by this component, no significant color gradients are observed. Finally, a complete set of evolutionary synthesis models have been develope d, covering a wide range in metallicity, 1/50 Z. < Z < 2 Z., and burst stre ngth, 1-10(-4). These models include nebular continuum and recombination an d forbidden-line emission.