Program: GN-2016A-Q-42

Title:Characterizing the Candidate Planetary Nebulae in the Galactic Center with Gemini GNIRS
PI:Janet Simpson
Co-I(s): Angela Cotera, Kris Sellgren, Deokkeun An, Solange Ramirez

Abstract

Planetary nebulae (PNe) are the ejected shells of intermediate mass stars that are ionized by the now-visible stellar cores. Although many PNe have been identified in the Galactic bulge, none has been detected in the central few hundred parsecs of the Milky Way, probably due to the high optical extinction. However, there should be many PNe in the Galactic Center (GC), considering the large increase in density of old stars towards the GC. In perusing GC spectra in the Spitzer Infrared Spectrograph archive, we have discovered several compact sources that have the highly excited spectra characteristic of PNe. These serendipitous candidate PNe may reside in the GC itself, or they may located in the bulge along lines of sight towards the GC. A test for the distance (and a requirement for further analysis) is a measurement of the extinction towards these objects. In this proposal we request 1 hour of time with GNIRS on Gemini-North to measure the Brackett gamma and Paschen beta hydrogen recombination lines in the two most compact, highest surface brightness candidate PNe. Spectra of PNe are used to elucidate the kinematics and chemical evolution of these old bulge stars.

Publications using this program's data