Disentangling the near-infrared continuum spectral components of the inner 500 pc of Mrk 573: two-dimensional maps

Abstract

We present a near infrared study of the spectral components of the continuum\nin the inner 500$\\times$500 pc$^2$ of the nearby Seyfert galaxy Mrk573 using\nadaptive optics near-infrared integral field spectroscopy with the instrument\nNIFS of the Gemini North Telescope at a spatial resolution of $\\sim$50 pc. We\nperformed spectral synthesis using the {\\sc starlight} code and constructed\nmaps for the contributions of different age components of the stellar\npopulation: young ($age\\leq100$ Myr), young-intermediate ($100<age\\leq700$\nMyr), intermediate-old ($700$ Myr $<age\\leq2$ Gyr) and old ($age>2$ Gyr) to the\nnear-IR K-band continuum, as well as their contribution to the total stellar\nmass. We found that the old stellar population is dominant within the inner 250\npc, while the intermediate age components dominate the continuum at larger\ndistances. A young stellar component contributes up to $\\sim$20% within the\ninner $\\sim$70 pc, while hot dust emission and featureless continuum components\nare also necessary to fit the nuclear spectrum, contributing up to 20% of the\nK-band flux there. The radial distribution of the different age components in\nthe inner kiloparsec of Mrk573 is similar to those obtained by our group for\nthe Seyfert galaxies Mrk1066, Mrk1157 and NGC1068 in previous works using a\nsimilar methodology. Young stellar populations ($\\leq$100 Myr) are seen in the\ninner 200-300 pc for all galaxies contributing with $\\ge$20% of the K-band\nflux, while the near-IR continuum is dominated by the contribution of\nintermediate-age stars ($t=$100 Myr-2 Gyr) at larger distances. Older stellar\npopulations dominate in the inner 250 pc.\n