Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-09-27
AIP Conf.Proc.804:15-19,2006
Astronomy and Astrophysics
Astrophysics
4 pages, 5 figures; contribution to proceedings of the conference "Planetary Nebulae as Astronomical Tools"
Scientific paper
10.1063/1.2146218
We present the latest results from our project to search for new planetary nebulae in nearby galaxies using Sloan Digital Sky Survey (SDSS) imaging data. Our method is based on photometric criteria and can be applied to galaxies where PNe appear as point sources. We applied these criteria to the whole area of M31 as scanned by SDSS, detecting 130 new PN candidates and 30 known PNe. All selected PNe candidates are located in the outer regions of M31. For 85 candidates follow-up spectroscopy was obtained with the 2.2m telescope at Calar Alto Observatory. The observations show that our method has a detection efficiency of about 82%. We discuss the 2D velocity field of the outer part of M31 based on our observed PN data. The PNe suggest an exponential disk scale length of 13 kpc along the minor axis. We discovered two PNe along the line of sight to Andromeda NE, a very low surface brightness giant stellar structure in the outer halo of M31. These two PNe are located at projected distances of ~48 kpc and ~41 kpc from the center of M31 and are the most distant PNe in M31 found up to now. Our data support the idea that Andromeda NE is located at the distance of M31. No PNe associated with other M31 satellites observed by the SDSS were found. Applying our method to other SDSS regions we checked data for the Local Group galaxies Sextans, Draco, Leo I, Pegasus, Sextans B and Leo A and recovered a known PN in Leo A. We re-measured its O/H and for the first time determined abundances of N/H, S/H, He/H as well as the electron number density Ne. We argue that the PN progenitor was formed ~1.5 Gyr ago during the strongest episode of star formation in Leo A.
Bell Eric F.
Grebel Eva Katharina
Harris Hugh C.
Kniazev Alexei Y.
Martinez-Delgado David
No associations
LandOfFree
A Search for PNe in Nearby Galaxies with SDSS Imaging Data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Search for PNe in Nearby Galaxies with SDSS Imaging Data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Search for PNe in Nearby Galaxies with SDSS Imaging Data will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-225204