ALMA detection and astrobiological potential of vinyl cyanide on Titan

Palmer, Maureen; Cordiner, Martin; Nixon, C. A.; Charnley, Steven B.; Teanby, N. A.; Kisiel, Zbigniew; Irwin, Patrick; Mumma, M. J.

doi:10.1126/sciadv.1700022

Cited by 76 publications

(91 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Observations were made with 39 antennas in the telescope array, which provided baselines in the range 15-349 m, with good u−v (Fourier) coverage of the sky. As with the previous work of Cordiner et al (2014Cordiner et al ( , 2015 and Palmer et al (2017), even this short integration time was sufficient to reach a high enough sensitivity for the detection of weak molecular emission lines from Titan. The present study was further facilitated by the larger number of functioning antennas compared to the 20-30 available in previous studies (e.g.…”

Section: Observationssupporting

confidence: 55%

“…The present study was further facilitated by the larger number of functioning antennas compared to the 20-30 available in previous studies (e.g. Cordiner et al (2014Cordiner et al ( , 2015 and Palmer et al (2017)). The data used in our study were taken from a single spectral window in the upper receiver sideband, containing 3840 channels and with a channel spacing of 488 kHz which (after Hanning smoothing by the correlator) corresponds to a spectral resolution of 976 kHz.…”

Section: Observationsmentioning

confidence: 99%

“…Given that Titan possesses seas of liquid hydrocarbon, vinyl cyanide could be a strong candidate for forming membranes of potential astrobiological importance. Although the presence of C 2 H 3 CN on Titan was previously inferred from mass-spectrometric measurements of its protonated form and neutral dissociation fragments (Vuitton et al 2007;Cui et al 2009), the first definitive detection of the molecule itself was by Palmer et al (2017), who reported observations of three mm-wave emission lines, making use of archival data obtained using the band 6 receiver of the Atacama Large Millimeter/submillimeter Array (ALMA) in 2014.…”

Section: Introductionmentioning

confidence: 99%

“…The Palmer et al (2017) observations were obtained at relatively low signal-to-noise and with insufficient resolution to provide reliable maps of the C 2 H 3 CN emission, so much remains unknown about the distribution of this important molecule within Titan's atmosphere. In this paper, we present new higher-sensitivity sub-mm data obtained from the ALMA Science Archive.…”

Section: Introductionmentioning

confidence: 99%

“…In this work, we follow up on the initial spectroscopic detection of C 2 H 3 CN on Titan by Palmer et al (2017) with the detection of three new C 2 H 3 CN rotational emission lines at submillimeter frequencies. These new, high-resolution detections have allowed for the first spatial distribution mapping of C 2 H 3 CN on Titan.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Mapping Vinyl Cyanide and Other Nitriles in Titan’s Atmosphere Using ALMA

Lai

Cordiner

Nixon

et al. 2017

Self Cite

View full text Add to dashboard Cite

Vinyl cyanide (C 2 H 3 CN) is theorized to form in Titan's atmosphere via high-altitude photochemistry and is of interest regarding the astrobiology of cold planetary surfaces due to its predicted ability to form cell membrane-like structures (azotosomes) in liquid methane. In this work, we follow up on the initial spectroscopic detection of C 2 H 3 CN on Titan by Palmer et al. (2017) with the detection of three new C 2 H 3 CN rotational emission lines at submillimeter frequencies. These new, high-resolution detections have allowed for the first spatial distribution mapping of C 2 H 3 CN on Titan. We present simultaneous observations of C 2 H 5 CN, HC 3 N, and CH 3 CN emission, and obtain the first (tentative) detection of C 3 H 8 (propane) at radio wavelengths. We present disk-averaged vertical abundance profiles, two-dimensional spatial maps, and latitudinal flux profiles for the observed nitriles. Similarly to HC 3 N and C 2 H 5 CN, which are theorized to be short-lived in Titan's atmosphere, C 2 H 3 CN is most abundant over the southern (winter) pole, whereas the longer-lived CH 3 CN is more concentrated in the north. This abundance pattern is consistent with the combined effects of high-altitude photochemical production, poleward advection, and the subsequent reversal of Titan's atmospheric circulation system following the recent transition from northern to southern winter. We confirm that C 2 H 3 CN and C 2 H 5 CN are most abundant at altitudes above 200 km. Using a 300 km step model, the average abundance of C 2 H 3 CN is found to be 3.03 ± 0.29 ppb, with a C 2 H 5 CN/C 2 H 3 CN abundance ratio of 2.43 ± 0.26. Our HC 3 N and CH 3 CN spectra can be accurately modeled using abundance gradients above the tropopause, with fractional scale-heights of 2.05 ± 0.16 and 1.63 ± 0.02, respectively.

show abstract

Section: Observationssupporting

confidence: 55%