Significant new planetary nebula discoveries as powerful probes of the LMC

Abstract

Our discovery and analysis of 452 new planetary nebulae (PNe) in the Large Magellanic Cloud (LMC) has tripled the number of known LMC PNe, providing a powerful new resource for probing the kinematics of the LMC as well as contributing fresh insight into the PN luminosity function (PNLF) which we now extend to over 10 magnitudes in [Oiii] and Hα. These discoveries have resulted from a new, deep (R ≡ 22), high resolution Hα map of the central 25 deg2 of the LMC, achieved by a process of multi-exposure median co-addition of a dozen 2-hour exposures. The resulting map is at least 1 magnitude deeper than the best wide-field narrow-band LMC images currently available and has proven a major resource for the discovery of emission objects of all kinds. As a result, the near complete sample of the PN population in the central 25 deg2 of the LMC has permitted truly meaningful quantitative determinations of the PNLF, distribution, abundances and kinematics. We briefly describe the importance of these PN discoveries, the additional spectroscopic confirmation of >2,000 compact emission sources, flux calibration, the newly derived electron temperatures and electron densities. © 2009 International Astronomical Union.