Bibcode
Hensley, K.; Balick, B.; Henry, R. B. C.; Corradi, R. L. M.; Kwitter, K. B.
Bibliographical reference
The Astrophysical Journal, Volume 807, Issue 2, article id. 181, 11 pp. (2015).
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7
2015
Journal
Citations
23
Refereed citations
14
Description
We present spectroscopy of nine planetary nebulae (PNe) in the outskirts
of M31, all but one obtained with the 10.4 m GTC telescope. These
sources extend our previous study of the oxygen abundance gradient of
M31 to galactocentric radii as large as 100 kpc. None of the targets are
bona fide members of a classical, metal-poor, and ancient halo. Two of
the outermost PNe have solar oxygen abundances, as well as radial
velocities consistent with the kinematics of the extended disk of M31.
The other PNe have a slightly lower oxygen content ([O/H] ∼ -0.4)
and in some cases large deviations from the disk kinematics. These PNe
support the current view that the external regions of M31 are the result
of a complex interaction and merger process, with evidence for a
widespread population of solar-metallicity stars produced in a starburst
that occurred ∼2 Gyr ago.
Related projects
Bipolar Nebulae
This project has three major objectives: 1) To determine the physico-chemical characteristics of bipolar planetary nebulae and symbiotic nebulae, to help understanding the origin of bipolarity and to test theoretical models, mainly models with binary central stars, aimed at explaining the observed morphology and kinematics. 2) To study the low
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