Formation of the Methyl Cation by Photochemistry in a Protoplanetary Disk

Abstract

Forty years ago it was proposed that gas phase organic chemistry in the interstellar medium was initiated by the methyl cation CH3+, but hitherto it has not been observed outside the Solar System. Alternative routes involving processes on grain surfaces have been invoked. Here we report JWST observations of CH3+ in a protoplanetary disk in the Orion star forming region. We find that gas-phase organic chemistry is activated by UV irradiation.

Published in Nature

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Cited by in corpus (21)

• PDRs4All III: JWST's NIR spectroscopic view of the Orion Bar
• OH mid-infrared emission as a diagnostic of H${}_2$O UV photodissociation. III. Application to planet-forming disks
• Sub-Doppler optical-optical double-resonance spectroscopy using a cavity-enhanced frequency comb probe
• PDRs4All XI. Detection of infrared CH${}^{+}$ and CH${}_3^{+}$ rovibrational emission in the Orion Bar and disk d203-506: evidence of chemical pumping
• A Novel Method to Estimate the FUV Flux and a Catalogue for Star-Hosting Discs in Nearby Star-Forming Regions
• PDRs4All. X. ALMA and JWST detection of neutral carbon in the externally irradiated disk d203-506: Undepleted gas-phase carbon
• PDRs4All. XII. FUV-driven formation of hydrocarbon radicals and their relation with PAHs
• PDRs4All VII. The 3.3 $\mu$m aromatic infrared band as a tracer of physical properties of the ISM in galaxies
• A tell-tale tracer for externally irradiated protoplanetary disks: comparing the [CI] 8727 A line and ALMA observations in proplyds
• XUE. JWST spectroscopy of externally irradiated disks around young intermediate-mass stars
• Externally irradiated young stars in NGC 3603. A JWST NIRSpec catalogue of pre-main-sequence stars in a massive star formation region
• Tracking the Chemical Evolution of Hydrocarbons Through Carbon Grain Supply in Protoplanetary Disks
• PDRs4All XV: CH radical and H${}_3^{+}$ molecular ion in the irradiated protoplanetary disk d203-506
• PDRs4All: XVIII. The evolution of the PAH ionisation and PAH size distribution across the Orion Bar
• H3+ in irradiated protoplanetary disks: Linking far-ultraviolet radiation and water vapor
• Line ratio identification of external photoevaporation
• High-resolution ro-vibrational and rotational spectroscopy of the open-shell, linear CCH${}^{+}$ ion (${}^3\Pi$)
• Spatial distribution of organics in the Horsehead nebula: Signposts of chemistry driven by atomic carbon
• Detection of CO${}_2$ ice in the planetary nebula NGC 6302
• Acenaphthene Derivatives as Signatures of C${}_{11}$H${}_9^{+}$ Reactivity with Methylated Naphthalenes
• PDRs4All XVIII. JWST-NIRCam Photometric properties of protoplanetary disks in the Orion Nebula Cluster