NEUTRON-CAPTURE ELEMENT ABUNDANCES IN MAGELLANIC CLOUD PLANETARY NEBULAE

Journal Article · Tue Nov 01 04:00:00 EDT 2016 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8205/831/1/L3· OSTI ID:22654174

Mashburn, A. L.; Sterling, N. C. ^[1]; Madonna, S. ^[2]; Dinerstein, Harriet L. ^[3]; Roederer, I. U. ^[4]

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1. Department of Physics, University of West Georgia, 1601 Maple Street, Carrollton, GA 30118 (United States)
2. Instituto de Astrofísica de Canarias, Departamento Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain)
3. Department of Astronomy, University of Texas, 2515 Speedway, C1400, Austin, TX 78712-1205 (United States)
4. Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109 (United States)

We present near-infrared spectra of 10 planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5 m Baade and 8.1 m Gemini South Telescopes, respectively. We detect Se and/or Kr emission lines in eight of these objects, the first detections of n -capture elements in Magellanic Cloud PNe. Our abundance analysis shows large s -process enrichments of Kr (0.6–1.3 dex) in the six PNe in which it was detected, and Se is enriched by 0.5–0.9 dex in five objects. We also estimate upper limits to Rb and Cd abundances in these objects. Our abundance results for the LMC are consistent with the hypothesis that PNe with 2–3 M {sub ⊙} progenitors dominate the bright end of the PN luminosity function in young gas-rich galaxies. We find no significant correlations between s -process enrichments and other elemental abundances, central star temperature, or progenitor mass, though this is likely due to our small sample size. We determine S abundances from our spectra and find that [S/H] agrees with [Ar/H] to within 0.2 dex for most objects, but is lower than [O/H] by 0.2–0.4 dex in some PNe, possibly due to O enrichment via third dredge-up. Our results demonstrate that n -capture elements can be detected in PNe belonging to nearby galaxies with ground-based telescopes, allowing s -process enrichments to be studied in PN populations with well-determined distances.

• OSTI ID: 22654174
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 831; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CAPTURE
CORRELATIONS
DETECTION
ELEMENT ABUNDANCE
EMISSION
HYPOTHESIS
INFRARED SPECTRA
LUMINOSITY
MAGELLANIC CLOUDS
MASS
NEUTRON REACTIONS
NUCLEOSYNTHESIS
PLANETARY NEBULAE
S PROCESS
SPECTROMETERS
STARS
TELESCOPES