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相关论文: Understanding the $\rm C_3H_2$ cyclic-to-linear ra…

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We report the detection of linear and cyclic isomers of C3H and C3H2 towards various starless cores and review the corresponding chemical pathways involving neutral (C3Hx with x=1,2) and ionic (C3Hx+ with x = 1,2,3) isomers. We highlight…

We use observations of the CI, CII, HI, and H_2 column densities along lines of sight in the Galactic plane to determine the formation rate of H_2 on grains and to determine chemical reaction rates with Polycyclic Aromatic Hydrocarbons.…

天体物理学 · 物理学 2009-11-13 Mark G. Wolfire , A. G. G. M. Tielens , David Hollenbach , Michael J. Kaufman

We report a detailed attempt to model the ortho-to-para abundance ratio of c-C3H2 so as to reproduce observed values in the cores of the well-known source TMC-1. According to observations, the ortho-to-para ratios vary, within large…

天体物理学 · 物理学 2009-11-11 In Hee Park , Valentine Wakelam , Eric Herbst

The increased sensitivity and spectral resolution of observed spectra towards the pre-stellar core L1544 are challenging the current physical and chemical models. With the aim of further constraining the structure of L1544 as well as…

星系天体物理 · 物理学 2025-08-29 J. Ferrer Asensio , S. S. Jensen , S. Spezzano , P. Caselli , F. O. Alves , O. Sipilä , E. Redaelli

The aim of this paper is to provide a new set of branching ratios for interstellar and planetary chemical networks based on a semi empirical model. We applied, instead of zero order theory (i.e. only the most exoergic decaying channel is…

星系天体物理 · 物理学 2018-05-02 M. Chabot , K. Beroff , P. Gratier , A. Jallat , V. Wakelam

Cyclic C5H (c-C5H), the radical formed by substituting an ethynyl group CCH for the hydrogen atom in the c-C3H radical, has been detected for the first time in the space. The c-C5H species is an isomer of the well-known linear radical l-C5H…

Yamamoto et al. (1987) reported the first detection of $c$-C$_3$H radical in {TMC-1} through its transition $2_{1 2} \to 1_{1 1}$ at 91.5 GHz. Mangum and Wootten (1990) detected $c$-C$_3$H through the transition $1_{1 0} \to 1_{1 1}$ at…

天体物理学 · 物理学 2007-05-23 Suresh Chandra , S. A. Shinde

Rate constants for the C(3P) + CH3OH reaction have been measured in a continuous supersonic flow reactor over the range 50 K to 296 K. C(3P) was created by the in-situ pulsed laser photolysis of CBr4, a multiphoton process which also…

Prestellar cores are unique laboratories for studies of the chemical and physical conditions preceding star formation. We observed the prestellar core L1544 in the fundamental transition of ortho-H2D+ (1_1,0-1_1,1) at different positions…

天体物理学 · 物理学 2009-11-11 C. Vastel , P. Caselli , C. Ceccarelli , T. G. Phillips , M. Wiedner , R. peng , M. Houde , C. Dominik

We present the observational result of a glycine precursor, methylamine (CH$_3$NH$_2$), together with methanol (CH$_3$OH) and methanimine (CH$_2$NH) towards high-mass star-forming regions, NGC6334I, G10.47+0.03, G31.41+0.3, and W51~e1/e2…

太阳与恒星天体物理 · 物理学 2019-09-04 Taiki Suzuki , Liton Majumdar , Kazuki Tokuda , Harumi Minamoto , Masatoshi Ohishi , Masao Saito , Tomoya Hirota , Hideko Nomura , Yoko Oya

Context: The $^{15}$N fractionation has been observed to show large variations among astrophysical sources, depending both on the type of target and on the molecular tracer used. These variations cannot be reproduced by the current chemical…

Pre-stellar cores are the basic unit for the formation of stars and stellar systems. The anatomy of the physical and chemical structures of pre-stellar cores is critical for understanding the star formation process. L1544 is a prototypical…

星系天体物理 · 物理学 2022-09-21 Yuxin Lin , Silvia Spezzano , Olli Sipilä , Anton Vasyunin , Paola Caselli

The reaction between the amidogen, NH, radical and the ethyl, C2H5, radical has been investigated by performing electronic structure calculations of the underlying doublet potential energy surface. Rate coefficients and product branching…

地球与行星天体物理 · 物理学 2018-10-25 Nadia Balucani , Dimitrios Skouteris , Cecilia Ceccarelli , Claudio Codella , Stefano Falcinelli , Marzio Rosi

We review the reactions between carbon chain molecules and radicals, namely Cn, CnH, CnH2, C2n+1O, CnN, HC2n+1N, with C, N and O atoms. Rate constants and branching ratios for these processes have been re-evaluated using experimental and…

星系天体物理 · 物理学 2015-06-17 Jean-Christophe Loison , Valentine Wakelam , Kevin M. Hickson , Astrid Bergeat , Raphael Mereau

We have mapped the dense dark core L1544 in H13CO+(1-0), DCO+(2-1), DCO+(3-2), N2H+(1-0), NTH+(3-2), N2D+(2-1), N2D+(3-2), C18O(1-0), and C17O(1-0) using the IRAM 30-m telescope. We have obtained supplementary observations of HC18O+(1-0),…

天体物理学 · 物理学 2019-08-17 P. Caselli , C. M. Walmsley , A. Zucconi , M. Tafalla , L. Dore , P. C. Myers

Multi-hydrogenated species with proper symmetry properties can present different spin configurations, and thus exist under different spin symmetry forms, labeled as para and ortho for two-hydrogen molecules. We investigated here the…

星系天体物理 · 物理学 2017-12-13 Romane Le Gal , Changjian Xie , Eric Herbst , Dahbia Talbi , Hua Guo , Sebastien Muller

Pre-stellar cores represent the earliest stage of the star- and planet-formation process. By characterizing the physical and chemical structure of these cores we can establish the initial conditions for star and planet formation and…

星系天体物理 · 物理学 2023-07-05 S. S. Jensen , S. Spezzano , P. Caselli , T. Grassi , T. Haugbølle

Based on a novel laboratory method, 14 mm-wave lines of the molecular ion H$_2$CCCH$^+$ have been measured in high resolution, and the spectroscopic constants of this asymmetric rotor determined with high accuracy. Using the Yebes 40 m and…

To provide constraints on the chemical processes responsible for the observed columns of organic species, we used NOEMA to observe the sight line toward NRAO150 in the 2mm spectral window. We targeted the low excitation lines of o-H2CO…

星系天体物理 · 物理学 2024-05-29 Maryvonne Gerin , Harvey Liszt , Jerome Pety , Alexandre Faure

Deuteration is a crucial tool to understand the complexity of interstellar chemical processes, especially when they involve the interplay of gas-phase and grain-surface chemistry. In the case of multiple deuteration, comparing observation…

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