Improved prospects for the detection of new Large Magellanic Cloud planetary nebulae

Abstract

The Large Magellanic Cloud (LMC) contains the nearest large extragalactic population of planetary nebulae (PNe). A shallow viewing angle and low interstellar reddening towards the LMC potentially means a larger, more complete flux-limited population can be assembled than for any other galaxy. These advantages appear to be reflected by the small gap between the catalogued ($\sim$700 PNe) and estimated ($1000\pm 250$ PNe) population size. With more detailed multi-wavelength studies the catalogued number of LMC PNe may fall, potentially widening this gap. We demonstrate here that the gap can be further bridged with improved optical and near-infrared imaging surveys. We present three [O III]-selected PNe discovered from ESO WFI observations of the 30 Doradus region and one serendipitous discovery from near-infrared Vista Magellanic Cloud (VMC) survey observations. The WFI PNe have resolved [O III] and H$\alpha$ nebulae that verify their PN nature and their [O III] fluxes place them 6--7 mag ($m_{5007}=20$--21 mag) fainter than the bright-end of the planetary nebula luminosity function (PNLF). Their faintness, small angular size and surrounding complex emission-line background explains why previous H$\alpha$ surveys of the region did not select them. We estimate there may be as many as 50--75 similar PNe awaiting discovery in the central $5\times 5$ degrees of the LMC. The VMC survey routinely detects PNe as red resolved nebulae that may allow some of this expected population to be recovered without traditional narrow-band imaging surveys. We demonstrate this potential with the first new VMC-selected PN which has a rare Wolf-Rayet [WC9]--[WC11] central star.

arXiv comment6 pages, 4 figures, 2 tables. Accepted for publication in Astronomy and Astrophysics

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Cited by in corpus (8)

• The VMC Survey IV. The LMC star formation history and disk geometry from four VMC tiles
• Symbiotic stars and other Halpha emission line stars towards the Galactic Bulge
• Identification of new Galactic symbiotic stars with SALT. I. Initial discoveries and other emission line objects
• The VMC Survey - VI. Quasars behind the Magellanic system
• The VMC Survey. II. A multi-wavelength study of LMC planetary nebulae and their mimics
• A multiwavelength analysis of planetary nebulae in the Large Magellanic Cloud
• The VMC survey -- LIII. Data release #7. Complete survey data and data from additional programmes
• Planetary Nebulae in the VISTA Magellanic Cloud (VMC) Survey