In Search of a Renaissance in Jewish Life

The Carl and Dorothy Bennett Lecture in Judaic Studies. A Lecture Presented by Edgar M. Bronfman, President of the World Jewish Congress.https://digitalcommons.fairfield.edu/bennettcenter-posters/1202/thumbnail.jp

Observations and chemical modeling of the isotopologues of formaldehyde and the cations of formyl and protonated formaldehyde in the hot molecular core G331.512-0.103

In the interstellar cold gas, the chemistry of formaldehyde (H$_2$CO) can be essential to explain the formation of complex organic molecules. On this matter, the massive and energetic protostellar object G331 is still unexplored and, hence, we carried out a comprehensive study of the isotopologues of H$_2$CO and formyl cation (HCO$^+$), and of protonated formaldehyde (H$_2$COH$^+$) through the APEX observations in the spectral window $\sim$159-356~GHz. We employed observational and theoretical methods to derive the physical properties of the molecular gas combining LTE and non-LTE analyses. Formaldehyde was characterized via 35 lines of H$_2$CO, H$_2^{13}$CO, HDCO and H$_2$C$^{18}$O. The formyl cation was detected via 8 lines of HCO$^+$, H$^{13}$CO$^+$, HC$^{18}$O$^+$ and HC$^{17}$O$^+$. Deuterium was clearly detected via HDCO, whereas DCO$^+$ remained undetected. H$_2$COH$^+$ was detected through 3 clean lines. According to the radiative analysis, formaldehyde appears to be embedded in a bulk gas with a wide range of temperatures ($T\sim$20-90 K), while HCO$^+$ and H$_2$COH$^+$ are primarily associated with a colder gas ($T\lesssim$ 30 K). The reaction H$_2$CO+HCO$^+ \rightarrow$ H$_2$COH$^+$ + CO is crucial for the balance of the three species. We used Nautilus gas-grain code to predict the evolution of their molecular abundances relative to H$_2$ which values at time scales $\sim$10$^3$ yr matched with the observations in G331: [H$_2$CO] = (0.2-2) $\times$10$^{-8}$, [HCO$^+$] = (0.5-4) $\times$10$^{-9}$ and [H$_2$COH$^+$] = (0.2-2) $\times$10$^{-10}$. Based on the molecular evolution of H$_2$CO, HCO$^+$ and H$_2$COH$^+$, we hypothesized about the young lifetime of G331, which is consistent with the active gas-grain chemistry of massive protostellar objects.Comment: 24 pages, 8 figures, 8 tables. Accepted for publication in The Astrophysical Journa

Isocyanic acid (HNCO) in the Hot Molecular Core G331.512-0.103: Observations and Chemical Modelling

The authors thank the anonymous referee for the useful comments that improved the article. CMC acknowledges the support of CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brazil, process number 41714/2016-6. This study was financed in part by the Coordenaçao de Aperfeiçoamento de Pessoal de Níıvel Su- perior – Brasil (CAPES) – Finance Code 001. LB acknowledges support from CONICYT (Comisión Nacional de Investigació Científica y Tecnolóogica) project Basal AFB-170002. EM acknowledges sup- port from the Brazilian agencies FAPESP (Fundaçao de Amparo à Pesquisa do Estado de São Paulo, grant 2014/22095-6) and CNPq (grant 150465/2019-0). MC acknowledges the financial support from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no 872081; from the Spanish National Research, Development, and Innovation plan (RDI plan) under the project PID2019-104002GB-C21; the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía and European Regional Development Fund (ERDF), ref. SOMM17/6105/UGR; the Ministerio de Ciencia, Innovación y Universidades (ref. COOPB20364); and by the Centro de Estudios Avanzados en Física, Matemáticas y Computación (CEAFMC) of the University of Huelva