XSHOOTER spectroscopy of the enigmatic planetary nebula Lin49 in the Small Magellanic Cloud

2016/07/04 by Masaaki Otsuka, F. Kemper, M. L. Leal-Ferreira +10
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Asymptotic giant branch #Galaxy #Large Magellanic Cloud #Metallicity #Nebula #Physics #Planetary nebula #Small Magellanic Cloud #Spectral energy distribution #Spectroscopy #Stars #Stellar, planetary, and galactic studies #astro-ph.GA #astro-ph.SR

paper · pdf · doi:10.1093/mnras/stw1615

24 pages, 17 figures, 17 tables, Accepted for publication by MNRAS

arxiv created 2016/07/04 · openalex publication_date 2016/07/11 · arxiv updated 2016/08/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We performed a detailed spectroscopic analysis of the fullerene C<inf>60</inf>-containing planetary nebula (PN) Lin49 in the Small Magellanic Cloud (SMC) using XSHOOTER at the European Southern Observatory Very Large Telescope and the <it>Spitzer</it>/Infrared Spectrograph instruments. We derived nebular abundances for nine elements. We used <scp>tlusty</scp> to derive photospheric parameters for the central star. Lin49 is C-rich and metal-deficient PN (<it>Z</it> ∼ 0.0006). The nebular abundances are in good agreement with asymptotic giant branch nucleosynthesis models for stars with initial mass 1.25 M<inf>⊙</inf> and metallicity <it>Z</it> = 0.001. Using the <scp>tlusty</scp> synthetic spectrum of the central star to define the heating and ionizing source, we constructed the photoionization model with <scp>cloudy</scp> that matches the observed spectral energy distribution (SED) and the line fluxes in the UV to far-IR wavelength ranges simultaneously. We could not fit the ∼1–5 μm SED using a model with 0.005–0.1-μm-sized graphite grains and a constant hydrogen density shell owing to the prominent near-IR excess, while at other wavelengths the model fits the observed values reasonably well. We argue that the near-IR excess might indicate either (1) the presence of very small particles in the form of small carbon clusters, small graphite sheets, or fullerene precursors, or (2) the presence of a high-density structure surrounding the central star. We found that SMC C<inf>60</inf> PNe show a near-IR excess component to lesser or greater degree. This suggests that these C<inf>60</inf> PNe might maintain a structure nearby their central star.

Citations

• C60: Buckminsterfullerene
• The size distribution of interstellar grains
• Improving Predictions for Helium Emission Lines
• CHEMICAL ABUNDANCES AND DUST IN THE HALO PLANETARY NEBULA K648 IN M15: ITS ORIGIN AND EVOLUTION BASED ON AN ANALYSIS OF MULTIWAVELENGTH DATA
• Depletion in post-AGB stars with a dusty disc. II.
• CLOUDY 90: Numerical Simulation of Plasmas and Their Spectra
• A Realistic Determination of the Error on the Primordial Helium Abundance: Steps toward Nonparametric Nebular Helium Abundances
• Detection of C 60 and C 70 in a Young Planetary Nebula
• Optical spectrum of the planetary nebula M 2-24
• Very deep spectroscopy of the bright Saturn nebula NGC 7009 - I. Observations and plasma diagnostics
• A Grid of Non‐LTE Line‐blanketed Model Atmospheres of O‐Type Stars
• Helium recombination spectra as temperature diagnostics for planetary nebulae
• The Two Micron All Sky Survey (2MASS)
• A deep survey of heavy element lines in planetary nebulae - I. Observations and forbidden-line densities, temperatures and abundances
• The Chemical Composition of the Sun
• Hubble Space Telescope Images of Magellanic Cloud Planetary Nebulae