Andrew M. Burkhardt
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View article: The Molecular Inventory of TMC-1 with GOTHAM Observations
The Molecular Inventory of TMC-1 with GOTHAM Observations Open
Spectral line surveys of the Taurus Molecular Cloud-1 (TMC-1) have led to the detection of more than 100 new molecular species, making it the most prolific source of interstellar molecular discoveries. These wide-band, high-sensitivity lin…
View article: The Molecular Inventory of TMC-1 with GOTHAM Observations
The Molecular Inventory of TMC-1 with GOTHAM Observations Open
Spectral line surveys of the Taurus Molecular Cloud-1 (TMC-1) have led to the detection of more than 100 new molecular species, making it the most prolific source of interstellar molecular discoveries. These wide-band, high-sensitivity lin…
View article: Discovery of the Seven-ring Polycyclic Aromatic Hydrocarbon Cyanocoronene (C<sub>24</sub>H<sub>11</sub>CN) in GOTHAM Observations of TMC-1
Discovery of the Seven-ring Polycyclic Aromatic Hydrocarbon Cyanocoronene (C<sub>24</sub>H<sub>11</sub>CN) in GOTHAM Observations of TMC-1 Open
We present the synthesis and laboratory rotational spectroscopy of the seven-ring polycyclic aromatic hydrocarbon (PAH) cyanocoronene (C 24 H 11 CN) using a laser-ablation-assisted cavity-enhanced Fourier transform microwave spectrometer. …
View article: The Missing Link of Sulfur Chemistry in TMC-1: The Detection of <i>c</i>-C<sub>3</sub>H<sub>2</sub>S from the GOTHAM Survey
The Missing Link of Sulfur Chemistry in TMC-1: The Detection of <i>c</i>-C<sub>3</sub>H<sub>2</sub>S from the GOTHAM Survey Open
We present the spectroscopic characterization of cyclopropenethione in the laboratory and detect it in space using the Green Bank Telescope Observations of TMC-1: Hunting Aromatic Molecules survey. The detection of this molecule—the missin…
View article: Discovery of interstellar 1-cyanopyrene: a four-ring polycyclic aromatic hydrocarbon in TMC-1
Discovery of interstellar 1-cyanopyrene: a four-ring polycyclic aromatic hydrocarbon in TMC-1 Open
Polycyclic aromatic hydrocarbons (PAHs) are expected to be the most abundant class of organic molecules in space. Their interstellar lifecycle is not well understood, and progress is hampered by difficulties detecting individual PAH molecu…
View article: Detections of interstellar 2-cyanopyrene and 4-cyanopyrene in TMC-1
Detections of interstellar 2-cyanopyrene and 4-cyanopyrene in TMC-1 Open
Polycyclic aromatic hydrocarbons (PAHs) are among the most ubiquitous compounds in the universe, accounting for up to ~25% of all interstellar carbon. Since most unsubstituted PAHs do not possess permanent dipole moments, they are invisibl…
View article: PDRs4All
PDRs4All Open
Context. Mid-infrared emission features are important probes of the properties of ionized gas and hot or warm molecular gas, which are difficult to probe at other wavelengths. The Orion Bar photodissociation region (PDR) is a bright, nearb…
View article: PDRs4All VIII: Mid-IR emission line inventory of the Orion Bar
PDRs4All VIII: Mid-IR emission line inventory of the Orion Bar Open
Mid-infrared emission features probe the properties of ionized gas, and hot or warm molecular gas. The Orion Bar is a frequently studied photodissociation region (PDR) containing large amounts of gas under these conditions, and was observe…
View article: PDRs4All
PDRs4All Open
Context . JWST has taken the sharpest and most sensitive infrared (IR) spectral imaging observations ever of the Orion Bar photodis-sociation region (PDR), which is part of the nearest massive star-forming region the Orion Nebula, and ofte…
View article: A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk
A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk Open
Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photo-dissociation regions (PDRs) on the surfac…
View article: A far-ultraviolet–driven photoevaporation flow observed in a protoplanetary disk
A far-ultraviolet–driven photoevaporation flow observed in a protoplanetary disk Open
Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surface…
View article: PDRs4All III: JWST's NIR spectroscopic view of the Orion Bar
PDRs4All III: JWST's NIR spectroscopic view of the Orion Bar Open
(Abridged) We investigate the impact of radiative feedback from massive stars on their natal cloud and focus on the transition from the HII region to the atomic PDR (crossing the ionisation front (IF)), and the subsequent transition to the…
View article: PDRs4All
PDRs4All Open
Context . The James Webb Space Telescope (JWST) has captured the most detailed and sharpest infrared (IR) images ever taken of the inner region of the Orion Nebula, the nearest massive star formation region, and a prototypical highly irrad…
View article: PDRs4All IV. An embarrassment of riches: Aromatic infrared bands in the Orion Bar
PDRs4All IV. An embarrassment of riches: Aromatic infrared bands in the Orion Bar Open
(Abridged) Mid-infrared observations of photodissociation regions (PDRs) are dominated by strong emission features called aromatic infrared bands (AIBs). The most prominent AIBs are found at 3.3, 6.2, 7.7, 8.6, and 11.2 $μ$m. The most sens…
View article: PDRs4All
PDRs4All Open
Context . Mid-infrared observations of photodissociation regions (PDRs) are dominated by strong emission features called aromatic infrared bands (AIBs). The most prominent AIBs are found at 3.3, 6.2, 7.7, 8.6, and 11.2 µm. The most sensiti…
View article: Detection of Interstellar $E$-1-cyano-1,3-butadiene in GOTHAM Observations of TMC-1
Detection of Interstellar $E$-1-cyano-1,3-butadiene in GOTHAM Observations of TMC-1 Open
We report the detection of the lowest energy conformer of $E$-1-cyano-1,3-butadiene ($E$-1-C$_4$H$_5$CN), a linear isomer of pyridine, using the fourth data reduction of the GOTHAM deep spectral survey toward TMC-1 with the 100 m Green Ban…
View article: Astronomical Detection of the Interstellar Anion C<sub>10</sub>H<sup>−</sup> toward TMC-1 from the GOTHAM Large Program on the Green Bank Telescope
Astronomical Detection of the Interstellar Anion C<sub>10</sub>H<sup>−</sup> toward TMC-1 from the GOTHAM Large Program on the Green Bank Telescope Open
Using data from the Green Bank Telescope (GBT) Observations of TMC-1: Hunting for Aromatic Molecules (GOTHAM) survey, we report the first astronomical detection of the C 10 H − anion. The astronomical observations also provided the necessa…
View article: Astronomical Detection of the Interstellar Anion C10H- towards TMC-1 from the GOTHAM Large Program on the GBT
Astronomical Detection of the Interstellar Anion C10H- towards TMC-1 from the GOTHAM Large Program on the GBT Open
Using data from the GOTHAM (GBT Observations of TMC-1: Hunting for Aromatic Molecules) survey, we report the first astronomical detection of the C10H- anion. The astronomical observations also provided the necessary data to refine the spec…
View article: Discovery of Interstellar 2-Cyanoindene (2-C<sub>9</sub>H<sub>7</sub>CN) in GOTHAM Observations of TMC-1
Discovery of Interstellar 2-Cyanoindene (2-C<sub>9</sub>H<sub>7</sub>CN) in GOTHAM Observations of TMC-1 Open
We present laboratory rotational spectroscopy of five isomers of cyanoindene (2-, 4-, 5-, 6-, and 7-cyanoindene) using a cavity Fourier transform microwave spectrometer operating between 6 and 40 GHz. Based on these measurements, we report…
View article: Discovery of Interstellar 2-Cyanoindene (2-C$_9$H$_7$CN) in GOTHAM Observations of TMC-1
Discovery of Interstellar 2-Cyanoindene (2-C$_9$H$_7$CN) in GOTHAM Observations of TMC-1 Open
We present laboratory rotational spectroscopy of five isomers of cyanoindene (2-, 4-, 5-, 6-, and 7-cyanoindene) using a cavity Fourier-transform microwave spectrometer operating between 6-40 GHz. Based on these measurements, we report the…
View article: A Detailed Temperature Map of the Archetypal Protostellar Shocks in L1157
A Detailed Temperature Map of the Archetypal Protostellar Shocks in L1157 Open
We present sensitive NH 3 (1,1)–(7,7) line images from the Karl G. Jansky Very Large Array toward successive shocks, which are associated with the blueshifted outflow lobe driven by the compact protobinary system L1157. Within a projection…
View article: PDRs4All: A JWST Early Release Science Program on Radiative Feedback from Massive Stars
PDRs4All: A JWST Early Release Science Program on Radiative Feedback from Massive Stars Open
Massive stars disrupt their natal molecular cloud material through radiative and mechanical feedback processes. These processes have profound effects on the evolution of interstellar matter in our Galaxy and throughout the universe, from t…
View article: A Search for Heterocycles in GOTHAM Observations of TMC-1
A Search for Heterocycles in GOTHAM Observations of TMC-1 Open
We have conducted an extensive search for nitrogen-, oxygen- and sulfur-bearing heterocycles toward Taurus Molecular Cloud 1 (TMC-1) using the deep, broadband centimeter-wavelength spectral line survey of the region from the GOTHAM large p…
View article: Discovery of Interstellar trans -cyanovinylacetylene (HC ≡ CCH = CHC ≡ N) and vinylcyanoacetylene (H 2 C = CHC 3 N) in GOTHAM Observations of TMC-1
Discovery of Interstellar trans -cyanovinylacetylene (HC ≡ CCH = CHC ≡ N) and vinylcyanoacetylene (H 2 C = CHC 3 N) in GOTHAM Observations of TMC-1 Open
We report the discovery of two unsaturated organic species, trans-(E)-cyanovinylacetylene and vinylcyanoacetylene, using the second data release of the GOTHAM deep survey toward TMC-1 with the 100m Green Bank Telescope. For both detections…
View article: First Images of Phosphorus Molecules toward a Protosolar Analog
First Images of Phosphorus Molecules toward a Protosolar Analog Open
The chemistry of phosphorus in star- and planet-forming regions is poorly understood, despite the central role of phosphorus in terrestrial biochemistry. We present Atacama Large Millimeter/submillimeter Array band 3 and 4 observations of …
View article: CH<sub>3</sub>-Terminated Carbon Chains in the GOTHAM Survey of TMC-1: Evidence of Interstellar CH<sub>3</sub>C<sub>7</sub>N
CH<sub>3</sub>-Terminated Carbon Chains in the GOTHAM Survey of TMC-1: Evidence of Interstellar CH<sub>3</sub>C<sub>7</sub>N Open
We report a systematic study of all known methyl carbon chains toward TMC-1 using the second data release of the GOTHAM survey, as well as a search for larger species. Using Markov Chain Monte Carlo simulations and spectral line stacking o…
View article: Detection of interstellar H<sub>2</sub>CCCHC<sub>3</sub>N
Detection of interstellar H<sub>2</sub>CCCHC<sub>3</sub>N Open
Context. The chemical pathways linking the small organic molecules commonly observed in molecular clouds to the large, complex, polycyclic species long suspected of being carriers of the ubiquitous unidentified infrared emission bands rema…
View article: METHYL-CARBON CHAIN CHEMISTRY IN TMC-1: THE FIRST INTERSTELLAR DETECTION OF METHYLCYANOTRIACETYLENE (<span class="roman">CH</span><sub><span class="roman">3</span></sub><span class="roman">C</span><sub><span class="roman">7</span></sub><span class="roman"
METHYL-CARBON CHAIN CHEMISTRY IN TMC-1: THE FIRST INTERSTELLAR DETECTION OF METHYLCYANOTRIACETYLENE (<span>CH</span><sub><span>3</span></sub><span>C</span><sub><span>7</span></sub><span class="roman" Open
Cold carbon chemistry in the interstellar medium is well-known for its efficient production of linear carbon chain molecules. Among the many variations on these species are the symmetric top methylpolyynes and methylcyanopolyynes (\\chem{C…