Planetary Nebulae in the Outer Disk and Halo of M31
Kniazev1, A.Y., Grebel, E.K., Zucker, D.B., Bell, E.F., Harris, H.C.
1MPIA, Heidelberg, Germany
We developed a method to identify planetary nebula (PN)
candidates in imaging data of the Sloan Digital Sky Survey
(SDSS). This method exploits the SDSS' five-band sampling of
emission lines in PN spectra, which results in a color
signature distinct from that of other sources and can be
applied to galaxies where PNe appear as point sources. We
tested this method with SDSS data of M31. In areas searched
by previous authors, we were able to recover about 6/7
of the earlier known PNe. All not recovered PNe are located
in overcrowded fields and were not found by the standard SDSS pipeline.
We then extended this search to the full area of M31's halo and disk
sampled by the SDSS. We present the method and early results from
this project.