TMC-1: probing the onset of chemical complexity in space

2026/04/29 by Marcelino Agundez, Jose Cernicharo · 1 voice
Physics and Astronomy · #astro-ph.GA

paper · pdf · doi:10.1021/acsearthspacechem.6c00026

Abstract

In recent years, the obsessive interest in the observation of TMC-1 has brought a boost in our knowledge of the chemistry of cold dark clouds. The number of molecules detected in this particular cloud has been more than doubled. Two observational programmes, GOTHAM and QUIJOTE, are responsible for this spectacular achievement. Here we provide an overall view of QUIJOTE, which is a line survey carried out in the Q band (31-50 GHz) with the Yebes 40m radiotelescope, summarize the actual observational status of TMC-1, and discuss the chemistry of this remarkable source. We highlight the successes and failures of state-of-the-art chemical models to describe its chemical composition, with a particular emphasis on the origin of PAHs, which is yet far from being understood.

Citations

• Discovery of 1H-cyclopent[cd]indene (c-C11H8) in TMC-1 with the QUIJOTE line survey: A new three-ringed polycyclic aromatic hydrocarbon
• Discovery of linear propadienone: Study of the chemistry of linear and cyclic H₂C₃O and H₂C₃S in TMC-1
• Ion-molecule routes towards cycles in TMC-1. An automated study of the C2H4 + CH2CCH+ reaction
• Piecing together formic acid isomerism in dark clouds. Detection of cis-formic acid in TMC-1 and astrochemical modeling
• The Molecular Inventory of TMC-1 with GOTHAM Observations
• Analysis of the isotopologues of CS, CCS, CCCS, HCS+, HCCS+, and H2CS in TMC-1 with the QUIJOTE line survey
• Discovery of interstellar phenalene (c-C₁₃H₁₀): A new piece for the chemical puzzle of PAHs in space
• Low D/H ratio for benzonitrile in TMC-1: Implication for the origin of polycyclic aromatic hydrocarbons in cold dark clouds
• Evidence for Phenylium Reactivity under Interstellar Relevant Conditions
• First detection of HS2 in a cold dark cloud
• Termination of bottom-up interstellar aromatic ring formation at C6H5+
• The Life and Times of Star-Forming Cores: an Analysis of Dense Gas in the STARFORGE Simulations
• The Missing Link of Sulfur Chemistry in TMC-1: The Detection of c-C3H2S from the GOTHAM Survey
• Detection of thioacetaldehyde (CH3CHS) in TMC-1: sulfur-oxygen differentiation along the hydrogenation sequence
• Identification of the interstellar 1-cyano propargyl radical (HCCCHCN) in TMC-1
• The rich interstellar reservoir of dinitriles: Detection of malononitrile and maleonitrile in TMC-1
• The 2024 KIDA network for interstellar chemistry
• More sulphur in TMC-1: Discovery of the NC₃S and HC₃S radicals with the QUIJOTE line survey
• Discovery of HCCCH2CCH in TMC-1 with the QUIJOTE line survey
• Discovery of the interstellar cyanoacetylene radical cation HC₃N⁺
• QUIJOTE discovery of the cation radicals HC5N+ and HC7N+
• The UMIST Database for Astrochemistry 2022
• Interstellar Detection of the Highly Polar Five-Membered Ring Cyanocyclopentadiene
• Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH₂CN) in TMC-1
• Detection of Interstellar HC₄NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions
• Ubiquitous Aromatic Carbon Chemistry at the Earliest Stages of Star Formation
• Gas phase Elemental abundances in Molecular cloudS (GEMS). II. On the quest for the sulphur reservoir in molecular clouds: the H₂S case
• Benzonitrile as a proxy for benzene in the cold ISM: low temperature rate coefficients for CN + C₆H₆
• Cometary Chemistry and the Origin of Icy Solar System Bodies, the view after Rosetta
• Gas phase Elemental abundances in Molecular cloudS (GEMS) I. The prototypical dark cloud TMC 1
• Detecting Weak Spectral Lines in Interferometric Data through Matched Filtering
• Discovery of the ubiquitous cation NS+ in space confirmed by laboratory spectroscopy
• Detection of the Aromatic Molecule Benzonitrile (c-C₆H₅CN) in the Interstellar Medium
• Coulomb explosion of polycyclic aromatic hydrocarbons induced by heavy cosmic rays: carbon chains production rates
• Possible detection of interstellar benzonitrile
• A New Reference Chemical Composition for TMC-1
• Gas and grain chemical composition in cold cores as predicted by the Nautilus 3-phase model
• The Cologne Database for Molecular Spectroscopy, CDMS, in the Virtual Atomic and Molecular Data Centre, VAMDC
• Probing non polar interstellar molecules through their protonated form: Detection of protonated cyanogen (NCCNH+)
• Chemistry of Dark Clouds: Databases, Networks, and Models
• 13CO Cores in Taurus Molecular Cloud
• Mixed aromatic–aliphatic organic nanoparticles as carriers of unidentified infrared emission features
• Oxygen depletion in dense molecular clouds: a clue to a low O2 abundance?
• The Disk Population of the Taurus Star-Forming Region
• A Unified Representation of Gas-Phase Element Depletions in the Interstellar Medium
• The Effects of Molecular Anions on the Chemistry of Dark Clouds
• Discovery of Interstellar Propylene (CH₂CHCH₃): Missing Links in Interstellar Gas-Phase Chemistry
• Cold Dark Clouds: The Initial Conditions for Star Formation
• The effect of uncertainties on chemical models of dark clouds
• Estimation and reduction of the uncertainties in chemical models: Application to hot core chemistry
• Detection of the linear radical HC4N in IRC+10216
• A 4 - 6 GHz Spectral Scan and 8 - 10 GHz Observations of the Dark Cloud TMC-1
• Molecular Carbon Chains and Rings in TMC-1

Cited by

• Detection of the Polycyclic Aromatic Hydrocarbon Phenalene (C₁₃H₁₀) in the Very Low Luminosity Object (VeLLO) MC27/L1521F

Discussions

• TMC-1: probing the onset of chemical complexity in space Agundez & Cernicharo arXiv (ACS E&SC) arxiv.org/abs/2604.26439 [bsky, 0 points, 0 comments]

Related

• Discovery of HCCCH2CCH in TMC-1 with the QUIJOTE line survey
• A New Reference Chemical Composition for TMC-1
• Chemistry of Dark Molecular Clouds
• First detection of HS2 in a cold dark cloud
• Observations of non complex organic molecules in the gas phase of the interstellar medium