Early Science from GOTHAM: Project Overview, Methods, and the Detection of Interstellar Propargyl Cyanide (HCCCH${}_2$CN) in TMC-1

Abstract

We present an overview of the GOTHAM (GBT Observations of TMC-1: Hunting Aromatic Molecules) Large Program on the Green Bank Telescope. This and a related program were launched to explore the depth and breadth of aromatic chemistry in the interstellar medium at the earliest stages of star formation, following our earlier detection of benzonitrile ($c$-C${}_6$H${}_5$CN) in TMC-1. In this work, details of the observations, use of archival data, and data reduction strategies are provided. Using these observations, the interstellar detection of propargyl cyanide (HCCCH${}_2$CN) is described, as well as the accompanying laboratory spectroscopy. We discuss these results, and the survey project as a whole, in the context of investigating a previously unexplored reservoir of complex, gas-phase molecules in pre-stellar sources. A series of companion papers describe other new astronomical detections and analyses.

Accepted in the Astrophysical Journal Letters

References in corpus (22)

• Detection of the Aromatic Molecule Benzonitrile ($c$-C${}_6$H${}_5$CN) in the Interstellar Medium
• 2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• The 2014 KIDA network for interstellar chemistry
• An Accurate Flux Density Scale from 50 MHz to 50 GHz
• Gas and grain chemical composition in cold cores as predicted by the Nautilus 3-phase model
• Chemistry of Dark Clouds: Databases, Networks, and Models
• Detection of HC11N in the Cold Dust Cloud TMC-1
• Oxygen depletion in dense molecular clouds: a clue to a low O2 abundance?
• Gas phase Elemental abundances in Molecular cloudS (GEMS) I. The prototypical dark cloud TMC 1
• A New Reference Chemical Composition for TMC-1
• Benzonitrile as a proxy for benzene in the cold ISM: low temperature rate coefficients for CN + C${}_6$H${}_6$
• Prevalence of Complex Organic Molecules in Starless and Prestellar Cores within the Taurus Molecular Cloud
• Discovery of the ubiquitous cation NS+ in space confirmed by laboratory spectroscopy
• Non-Detection of HC${}_{11}$N toward TMC-1: Constraining the Chemistry of Large Carbon-Chain Molecules
• A Post-AGB Star in the Small Magellanic Cloud Observed with the Spitzer Infrared Spectrograph
• Detection of Interstellar HC${}_4$NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions
• Structure and stability in TMC-1: analysis of NH${}_3$ molecular line and Herschel continuum data
• Deep K-band observations of TMC-1 with the Green Bank Telescope: Detection of HC7O, non-detection of HC11N, and a search for new organic molecules
• Detection of HC${}_5$N and HC${}_7$N Isotopologues in TMC-1 with the Green Bank Telescope
• The Rich Circumstellar Chemistry of SMP LMC 11
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Cited by in corpus (43)

• Detection of Two Interstellar Polycyclic Aromatic Hydrocarbons via Spectral Matched Filtering
• 2021 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules
• Discovery of the Pure Polycyclic Aromatic Hydrocarbon Indene ($c$-C${}_9$H${}_8$) with GOTHAM Observations of TMC-1
• Discovery of Interstellar 2-Cyanoindene (2-C${}_9$H${}_7$CN) in GOTHAM Observations of TMC-1
• The Composition and Chemistry of Titan's Atmosphere
• Discovery of the 7-ring PAH Cyanocoronene (C${}_{24}$H${}_{11}$CN) in GOTHAM Observations of TMC-1
• Discovery of the propargyl radical (CH2CCH) in TMC-1: one of the most abundant radicals ever found and a key species for cyclization to benzene in cold dark clouds
• Aromatics and Cyclic Molecules in Molecular Clouds: A New Dimension of Interstellar Organic Chemistry
• Interstellar Detection of 2-Cyanocyclopentadiene, C${}_5$H${}_5$CN, a Second Five-Membered Ring Toward TMC-1
• A Search for Heterocycles in GOTHAM Observations of TMC-1
• Detection of Interstellar HC${}_4$NC and an Investigation of Isocyanopolyyne Chemistry under TMC-1 Conditions
• Carbon-Chain Chemistry in the Interstellar Medium
• A study of C4H3N isomers in TMC-1: line by line detection of HCCCH2CN
• Astronomical Detection of the Interstellar Anion C10H- towards TMC-1 from the GOTHAM Large Program on the GBT
• An overview of desorption parameters of Volatile and Complex Organic Molecules: A systematic dig on experimental literature
• The spatial distribution of an aromatic molecule, C6H5CN, in the cold dark cloud TMC-1
• Detection of the propargyl radical at lambda 3 mm
• Machine Learning of Interstellar Chemical Inventories
• Detection of Interstellar $E$-1-cyano-1,3-butadiene in GOTHAM Observations of TMC-1
• Evolutionary view through the starless cores in Taurus: deuteration in TMC 1-C and TMC 1-CP
• CH3-Terminated Carbon Chains in the GOTHAM Survey of TMC-1: Evidence of Interstellar CH3C7N
• Predicting binding energies of astrochemically relevant molecules via machine learning
• Complex organic molecules detected in twelve high-mass star-forming regions with Atacama Large Millimeter/submillimeter Array (ALMA)
• Discovery of Interstellar trans-cyanovinylacetylene (HCCCH=CHCN) and vinylcyanoacetylene (H${}_2$C=CHC${}_3$N) in GOTHAM Observations of TMC-1
• Energetic Electron Irradiations of Amorphous and Crystalline Sulphur-Bearing Astrochemical Ices
• Rotational spectra of interstellar N- and CN-PAHs: pyrene and coronene
• Cyanopolyyne chemistry in the L1544 prestellar core: new insights from GBT observations
• The Role of Terahertz and Far-IR Spectroscopy in Understanding the Formation and Evolution of Interstellar Prebiotic Molecules
• The High-Resolution Far- to Near-Infrared Anharmonic Absorption Spectra of Cyano-Substituted Polycyclic Aromatic Hydrocarbons from 300-6200 cm${}^{-1}$
• A deep search for large complex organic species toward IRAS16293-2422 B at 3 mm with ALMA
• Doubly substituted isotopologues of HCCCN in TMC-1: Detection of D13CCCN, DC13CCN, DCC13CN, DCCC15N, H13C13CCN, H13CC13CN, HC13C13CN, HCC13C15N, and HC13CC15N
• A Q-band line survey towards Orion KL using the Tianma radio telescope
• Reexploring Molecular Complexity with ALMA: Insights into chemical differentiation from the molecular composition of hot cores in Sgr B2(N2)
• Sensitivity Analysis of Aromatic Chemistry to Gas-Phase Kinetics in a Dark Molecular Cloud Model
• Astrochemical Modeling of Propargyl Radical Chemistry in TMC-1
• Complex organic molecules uncover deeply embedded precursors of hot cores
• Low NH${}_3$/H${}_2$O ratio in comet C/2020 F3 (NEOWISE) at 0.7 au from the Sun
• Spectral-line Survey of the Region of Massive Star Formation W51e1/e2 in the 4 mm Wavelength Range
• Unmasking the physical information inherent to interstellar spectral line profiles with Machine Learning. I. Application of LTE to HCN and HNC transitions
• Nitrogen- and nitrogen-oxygen-bearing organic molecules in comet 67P/Churyumov-Gerasimenko: An untargeted investigation
• Rotational Spectra and Search for Aromatic Imines: 9-Iminofluorene and Benzophenone imine
• Carbon chain diversity in L1544 and IRAS 16293-2422: an astrochemical pathfinder study for the SKAO
• An 18 - 25 GHz spectroscopic survey of southern hemisphere dense cores