A new Planetary Nebula in the outer reaches of the Galaxy

Abstract

A proper determination of the abundance gradient in the Milky Way requires the observation of objects at large galactiocentric distances. With this aim, we are exploring the planetary nebula population towards the Galactic Anticentre. In this article, the discovery and physico-chemical study of a new planetary nebula towards the Anticentre direction, IPHASX J052531.19+281945.1 (PNG 178.1-04.0), is presented. The planetary nebula was discovered from the IPHAS survey. Long-slit follow-up spectroscopy was carried out to confirm its planetary nebula nature and to calculate its physical and chemical characteristics. The newly discovered planetary nebula turned out to be located at a very large galactocentric distance (D_GC=20.8+-3.8 kpc), larger than any previously known planetary nebula with measured abundances. Its relatively high oxygen abundance (12+log(O/H) = 8.36+-0.03) supports a flattening of the Galactic abundance gradient at large galactocentric distances rather than a linearly decreasing gradient.

7 pages, 4 figures

References in corpus (7)

• The Magellanic Cloud Calibration of the Galactic Planetary Nebula Distance Scale
• Abundances of Galactic Anticenter Planetary Nebulae and the Oxygen Abundance Gradient in the Galactic Disk
• Planetary Nebula Abundances and Morphology: Probing the Chemical Evolution of the Milky Way
• Planetary nebulae abundances and stellar evolution
• High Spatial Resolution Galactic 3D Extinction Mapping with IPHAS
• IPHAS extinction distances to Planetary Nebulae
• Modeling Star counts in the Monoceros stream and the Galactic anti-centre

Cited by in corpus (9)

• The VST Photometric Halpha Survey of the Southern Galactic Plane and Bulge (VPHAS+)
• The Hα surface brightness - radius relation: a robust statistical distance indicator for planetary nebulae
• The Second Data Release of the INT Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS DR2)
• A catalogue of integrated H-alpha fluxes for 1,258 Galactic planetary nebulae
• New Galactic supernova remnants discovered with IPHAS
• First release of the IPHAS Catalogue of New Extended Planetary Nebulae
• Flux calibration of the AAO/UKST SuperCOSMOS H-alpha Survey
• High resolution H-alpha imaging of the Northern Galactic Plane, and the IGAPS images database
• Ionisation as indicator for cosmic ray acceleration