Studying the Fullerene Nest: JWST Observations of the Planetary Nebula Tc 1. II. A Spectroscopic and Spatial Study of C$_{60}$ and C$_{70}$ Emission
Year: 2026
Type: preprint
Abstract: We present a detailed analysis of the fullerene emission bands in JWST MIRI/MRS observations of the planetary nebula Tc 1. The observations reveal the emission features due to neutral C$_{60}$ and C$_{70}$ in unprecedented detail. The combined fullerene emission represents $\sim$2.6% of the total infrared output, suggesting that $\sim$0.6% of the carbon budget is locked up in fullerenes. We find no clear evidence for C$_{60}^+$, C$_{70}^+$ or C$_{60}^-$ in the spectrum. The high spectral resolution allows us to separate the fullerene bands from atomic emission lines for the first time, allowing for a much better characterization of the band profiles and yielding more accurate band ratios than previous observations. We see no spatial variation in the individual C$_{60}$ and C$_{70}$ band profile shapes across all pixels. The 17.4 and 18.9 $μ$m C$_{60}$ bands show clear resolved ro-vibrational structure in their profiles, and similar structured emission is seen in the 12.5, 14.8, 17.7, and 21.8 $μ$m C$_{70}$ bands, further establishing that all emitting fullerene molecules are in the gas phase. We report a higher 7.0/18.9 $μ$m C$_{60}$ band ratio ($\sim$1.4-1.9) than previously reported ($\sim$1.3). We note that all bands, except the 8.5 $μ$m band, contain a significant contribution from C$_{70}$, complicating the analysis. The fullerene emission is spatially concentrated in a thin, asymmetric shell at a radius of 5-6$''$ from the central star. The shell lies at the outer edge of the core of the nebula, which was ejected in a single, brief episode $\gtrsim$4,000 years ago.
Source: arXiv (Cornell University)
Authors: Giese, M. M., Cami, J., Van Schuylenbergh, S., Peeters, E., Bhatt, C., Van De Putte, D., Baerts, C., Barlow, M. J., Bernard-Salas, J., Candian, A., Changala, P. B., Cox, N. L. J., Dinerstein, H. L., Esposito, V. J., García-Hernández, D. A., Gómez-Muñoz, M. A., Justtanont, K., Kraemer, K. E., Lagadec, E., Manchado, A., Ibero, A. Monreal, Sahai, R., Sidhu, A., Sloan, G. C., Sterling, N. C., Tielens, A. G. G. M., Walsh, J. R., Wesson, R., Whitman, J. C., Zijlstra, A., Finazzi, L., Martens, J., Berden, G., Oomens, J.
Institutions: Western University, University College London, The University of Texas at Austin, Chapman University, Leiden University, Leiden Observatory, University of North Carolina at Chapel Hill, Space Telescope Science Institute, University of West Georgia, University of Maryland, College Park, European Southern Observatory, Cardiff University, University of Manchester, Radboud University Nijmegen, HFML-FELIX
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7225762000