Published in ApJS, Vol. 147, pp.29-59, 2003.

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PALOMAR/LAS CAMPANAS IMAGING ATLAS OF BLUE COMPACT DWARF GALAXIES: I. IMAGES AND INTEGRATED PHOTOMETRY

A. Gil de Paz 1,2,3 B. F. Madore 1,3, and O. Pevunova 1


1 NASA/IPAC Extragalactic Database, California Institute of Technology, MS 100-22, Pasadena, CA 91125; agpaz, barry, olga@ipac.caltech.edu
2 Jet Propulsion Laboratory, California Institute of Technology, MS 183-900, Pasadena, CA 91109
3 The Observatories, Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101


Abstract. We present B, R, and Halpha images for a total of 114 nearby galaxies (vhelio < 4000 km s-1)that, with exception of 9 objects, are classified as Blue Compact Dwarfs (BCDs). BR integrated magnitudes, Halpha fluxes and Halpha equivalent widths for all the objects in the sample are presented. A new set of quantitative, observational criteria for a galaxy to be classified as a BCD is proposed. These criteria include a limit on the K-band luminosity (i.e. stellar mass; MK > -21 mag), peak surface brigthness (µB, peak < 22mag/arcsec2), and color at the peak surface brightness (µB, peak - µR, peak leq 1). Halpha emission is detected in all but three sample galaxies. Typical color, absolute magnitude, and Halpha luminosity are (B - R) = 0.7 ± 0.3 mag, MB = -16.1 ± 1.4 mag, and log(LHalpha) = 40.0 ± 0.6 (erg s-1). Galaxies morphologically classified as nE and iE BCDs within our sample show lower Halpha equivalent widths and redder colors, on average, than the iI and i0-type BCDs. For most of the galaxies the presence of an evolved stellar population is required to explain their observed properties; only the most metal-poor BCDs (e.g. I Zw 18, Tol 65) are still compatible with a pure, young burst. The flux-calibrated and WCS-compliant images in this Atlas are individually available through the NASA/IPAC Extragalactic Database (NED) image server and collectively through a dedicated web page at (/level5/Sept02/Palco_BCD/).


Key words: galaxies: evolution - galaxies: starburst - galaxies: dwarf - galaxies: fundamental parameters - galaxies: - photometry - atlases


Table of Contents

INTRODUCTION

SAMPLE

DEFINITION OF BLUE COMPACT DWARF GALAXY

OBSERVATIONS

REDUCTION
Flux-calibration
Astrometry

MAPS AND MORPHOLOGICAL CLASSIFICATION

FITS IMAGES - INDIVIDUAL MAPS

INTEGRATED PHOTOMETRY

CONCLUSIONS

APPENDIX A. EMISSION-LINE CONTINUUM SUBTRACTION USING BROAD-BAND IMAGES

REFERENCES

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