Detection of CH3+ in the O-rich planetary nebula NGC 6302

Charmi Bhatt; Jan Cami; Els Peeters; Nicholas Clark; Paula Moraga Baez; Kevin Volk; G. C. Sloan; Joel H. Kastner; Harriet L. Dinerstein; Mikako Matsuura; Bruce Balick; Kathleen E. Kraemer; Kay Justtanont; Olivia Jones; Raghvendra Sahai; Isabel Aleman; Michael J. Barlow; Jeronimo Bernard-Salas; Joris Blommaert; Naomi Hirano; Patrick Kavanagh; Francisca Kemper; Eric Lagadec; J. Martin Laming; Frank Molster; Hektor Monteiro; Anita M. S. Richards; N. C. Sterling; Maryam Torki; Peter A. M. van Hoof; Jeremy R. Walsh; L. B. F. M. Waters; Roger Wesson; Finnbar Wilson; Nicholas J. Wright; Albert A. Zijlstra

doi:10.3847/1538-4357/ae1020

Detection of CH₃⁺ in the O-rich planetary nebula NGC 6302

Charmi Bhatt^*, Jan Cami, Els Peeters, Nicholas Clark, Paula Moraga Baez, Kevin Volk, G. C. Sloan, Joel H. Kastner, Harriet L. Dinerstein, Mikako Matsuura, Bruce Balick, Kathleen E. Kraemer, Kay Justtanont, Olivia Jones, Raghvendra Sahai, Isabel Aleman, Michael J. Barlow, Jeronimo Bernard-Salas, Joris Blommaert, Naomi HiranoPatrick Kavanagh, Francisca Kemper, Eric Lagadec, J. Martin Laming, Frank Molster, Hektor Monteiro, Anita M. S. Richards, N. C. Sterling, Maryam Torki, Peter A. M. van Hoof, Jeremy R. Walsh, L. B. F. M. Waters, Roger Wesson, Finnbar Wilson, Nicholas J. Wright, Albert A. Zijlstra

^*Corresponding author for this work

School of Mathematical and Physical Sciences

Research output: Contribution to journal › Article › peer-review

Abstract

Planetary nebulae are sites where ejected stellar material evolves into complex molecules, but the precise physical conditions and chemical routes that govern these processes are unclear. The presence of abundant carbon-rich molecules in O-rich environments poses particular challenges. Here we report the first detection of methyl cation (CH₃⁺) in any planetary nebula, observed in the O-rich nebula NGC 6302 using JWST MIRI/Medium Resolution Spectrometer observations. CH₃⁺ is a key driver of organic chemistry in UV-irradiated environments. Spatially resolved observations reveal that CH₃⁺ is colocated with ¹²CO, H₂, H ii, HCO⁺, and polycyclic aromatic hydrocarbons. LTE modeling of the CH 3 + emission yields excitation temperatures of 500-800 K in the inner bubble and torus, rising to 1000-2000 K in the outer bubble of NGC 6302, with column densities ranging from ∼10¹¹ to 10¹³ cm⁻². This detection suggests that hydrocarbon radical chemistry must be incorporated into planetary nebulae chemical models. Further near-IR observations are crucial to map different chemical networks operating in these environments.

Original language	English
Article number	67
Pages (from-to)	1-15
Number of pages	15
Journal	Astrophysical Journal
Volume	995
Issue number	1
DOIs	https://doi.org/10.3847/1538-4357/ae1020
Publication status	Published - 10 Dec 2025

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© 2025. The Author(s). Published by the American Astronomical Society. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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Bhatt, C., Cami, J., Peeters, E., Clark, N., Moraga Baez, P., Volk, K., Sloan, G. C., Kastner, J. H., Dinerstein, H. L., Matsuura, M., Balick, B., Kraemer, K. E., Justtanont, K., Jones, O., Sahai, R., Aleman, I., Barlow, M. J., Bernard-Salas, J., Blommaert, J., ... Zijlstra, A. A. (2025). Detection of CH₃⁺ in the O-rich planetary nebula NGC 6302. Astrophysical Journal, 995(1), 1-15. Article 67. https://doi.org/10.3847/1538-4357/ae1020

@article{32bac63989ce4416811e1ec47b9297ff,

title = "Detection of CH3+ in the O-rich planetary nebula NGC 6302",

abstract = "Planetary nebulae are sites where ejected stellar material evolves into complex molecules, but the precise physical conditions and chemical routes that govern these processes are unclear. The presence of abundant carbon-rich molecules in O-rich environments poses particular challenges. Here we report the first detection of methyl cation (CH3+) in any planetary nebula, observed in the O-rich nebula NGC 6302 using JWST MIRI/Medium Resolution Spectrometer observations. CH3+ is a key driver of organic chemistry in UV-irradiated environments. Spatially resolved observations reveal that CH3+ is colocated with 12CO, H2, H ii, HCO+, and polycyclic aromatic hydrocarbons. LTE modeling of the CH 3 + emission yields excitation temperatures of 500-800 K in the inner bubble and torus, rising to 1000-2000 K in the outer bubble of NGC 6302, with column densities ranging from ∼1011 to 1013 cm−2. This detection suggests that hydrocarbon radical chemistry must be incorporated into planetary nebulae chemical models. Further near-IR observations are crucial to map different chemical networks operating in these environments.",

author = "Charmi Bhatt and Jan Cami and Els Peeters and Nicholas Clark and \{Moraga Baez\}, Paula and Kevin Volk and Sloan, \{G. C.\} and Kastner, \{Joel H.\} and Dinerstein, \{Harriet L.\} and Mikako Matsuura and Bruce Balick and Kraemer, \{Kathleen E.\} and Kay Justtanont and Olivia Jones and Raghvendra Sahai and Isabel Aleman and Barlow, \{Michael J.\} and Jeronimo Bernard-Salas and Joris Blommaert and Naomi Hirano and Patrick Kavanagh and Francisca Kemper and Eric Lagadec and Laming, \{J. Martin\} and Frank Molster and Hektor Monteiro and Richards, \{Anita M. S.\} and Sterling, \{N. C.\} and Maryam Torki and \{van Hoof\}, \{Peter A. M.\} and Walsh, \{Jeremy R.\} and Waters, \{L. B. F. M.\} and Roger Wesson and Finnbar Wilson and Wright, \{Nicholas J.\} and Zijlstra, \{Albert A.\}",

note = "{\textcopyright} 2025. The Author(s). Published by the American Astronomical Society. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.",

year = "2025",

month = dec,

day = "10",

doi = "10.3847/1538-4357/ae1020",

language = "English",

volume = "995",

pages = "1--15",

journal = "Astrophysical Journal",

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Bhatt, C, Cami, J, Peeters, E, Clark, N, Moraga Baez, P, Volk, K, Sloan, GC, Kastner, JH, Dinerstein, HL, Matsuura, M, Balick, B, Kraemer, KE, Justtanont, K, Jones, O, Sahai, R, Aleman, I, Barlow, MJ, Bernard-Salas, J, Blommaert, J, Hirano, N, Kavanagh, P, Kemper, F, Lagadec, E, Laming, JM, Molster, F, Monteiro, H, Richards, AMS, Sterling, NC, Torki, M, van Hoof, PAM, Walsh, JR, Waters, LBFM, Wesson, R, Wilson, F, Wright, NJ & Zijlstra, AA 2025, 'Detection of CH₃⁺ in the O-rich planetary nebula NGC 6302', Astrophysical Journal, vol. 995, no. 1, 67, pp. 1-15. https://doi.org/10.3847/1538-4357/ae1020

TY - JOUR

T1 - Detection of CH3+ in the O-rich planetary nebula NGC 6302

AU - Bhatt, Charmi

AU - Cami, Jan

AU - Peeters, Els

AU - Clark, Nicholas

AU - Moraga Baez, Paula

AU - Volk, Kevin

AU - Sloan, G. C.

AU - Kastner, Joel H.

AU - Dinerstein, Harriet L.

AU - Matsuura, Mikako

AU - Balick, Bruce

AU - Kraemer, Kathleen E.

AU - Justtanont, Kay

AU - Jones, Olivia

AU - Sahai, Raghvendra

AU - Aleman, Isabel

AU - Barlow, Michael J.

AU - Bernard-Salas, Jeronimo

AU - Blommaert, Joris

AU - Hirano, Naomi

AU - Kavanagh, Patrick

AU - Kemper, Francisca

AU - Lagadec, Eric

AU - Laming, J. Martin

AU - Molster, Frank

AU - Monteiro, Hektor

AU - Richards, Anita M. S.

AU - Sterling, N. C.

AU - Torki, Maryam

AU - van Hoof, Peter A. M.

AU - Walsh, Jeremy R.

AU - Waters, L. B. F. M.

AU - Wesson, Roger

AU - Wilson, Finnbar

AU - Wright, Nicholas J.

AU - Zijlstra, Albert A.

N1 - © 2025. The Author(s). Published by the American Astronomical Society. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

PY - 2025/12/10

Y1 - 2025/12/10

N2 - Planetary nebulae are sites where ejected stellar material evolves into complex molecules, but the precise physical conditions and chemical routes that govern these processes are unclear. The presence of abundant carbon-rich molecules in O-rich environments poses particular challenges. Here we report the first detection of methyl cation (CH3+) in any planetary nebula, observed in the O-rich nebula NGC 6302 using JWST MIRI/Medium Resolution Spectrometer observations. CH3+ is a key driver of organic chemistry in UV-irradiated environments. Spatially resolved observations reveal that CH3+ is colocated with 12CO, H2, H ii, HCO+, and polycyclic aromatic hydrocarbons. LTE modeling of the CH 3 + emission yields excitation temperatures of 500-800 K in the inner bubble and torus, rising to 1000-2000 K in the outer bubble of NGC 6302, with column densities ranging from ∼1011 to 1013 cm−2. This detection suggests that hydrocarbon radical chemistry must be incorporated into planetary nebulae chemical models. Further near-IR observations are crucial to map different chemical networks operating in these environments.

AB - Planetary nebulae are sites where ejected stellar material evolves into complex molecules, but the precise physical conditions and chemical routes that govern these processes are unclear. The presence of abundant carbon-rich molecules in O-rich environments poses particular challenges. Here we report the first detection of methyl cation (CH3+) in any planetary nebula, observed in the O-rich nebula NGC 6302 using JWST MIRI/Medium Resolution Spectrometer observations. CH3+ is a key driver of organic chemistry in UV-irradiated environments. Spatially resolved observations reveal that CH3+ is colocated with 12CO, H2, H ii, HCO+, and polycyclic aromatic hydrocarbons. LTE modeling of the CH 3 + emission yields excitation temperatures of 500-800 K in the inner bubble and torus, rising to 1000-2000 K in the outer bubble of NGC 6302, with column densities ranging from ∼1011 to 1013 cm−2. This detection suggests that hydrocarbon radical chemistry must be incorporated into planetary nebulae chemical models. Further near-IR observations are crucial to map different chemical networks operating in these environments.

UR - https://www.scopus.com/pages/publications/105031744910

U2 - 10.3847/1538-4357/ae1020

DO - 10.3847/1538-4357/ae1020

M3 - Article

AN - SCOPUS:105031744910

SN - 0004-637X

VL - 995

SP - 1

EP - 15

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1

M1 - 67

ER -

Detection of CH₃⁺ in the O-rich planetary nebula NGC 6302

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