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

  • Gil de Paz, Armando
  • Zamorano Calvo, Jaime
  • Gallego Maestro, Jesús
  • Domínguez, F. de B.
We have obtained optical (BVR, [O III]ƛ 5007 Å and H_α), near infrared (JHK) imaging and long-slit optical spectroscopy for the Blue Compact 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 currently star-forming regions, intermediate aged starburst and underlying stellar population. We also describe the evolutionary synthesis models used in Paper II. The R and H_α luminosity distributions of the galaxy star-forming regions show maxima at M-R = -9.5^m and L_H_α = 10^37.3 ergs^-l. The underlying stellar population shows an exponential surface brigthness profile with central value, μ_E,0 = 21.5 mag arcsec^-2, and scale, α=0.88 kpc, both measured in the R-band image. In the galaxy outer regions, dominated by this component, no significant color gradients are observed. Finally, a complete set of evolutionary synthesis models have been developed, covering a wide range in metallicity, 1/50 Z_⨀< Z < 2 Z_⨀, and burst strength, 1-10^-4. These models include nebular continuum and recombination and forbidden-line emission.