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arXiv · 1605.02161

Survey Observations of a Possible Glycine Precursor, Methanimine (CH$_2$NH)

Taiki Suzuki·Masatoshi Ohishi·Tomoya Hirota·Masao Saito·Liton Majumdar·Valentine Wakelam
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Abstract

We conducted survey observations of a glycine precursor, methanimine or methylenimine (CH$_2$NH), with the NRO 45 m telescope and the SMT telescope towards 12 high-mass and two low-mass star-forming regions in order to increase number of CH$_2$NH sources and to better understand the characteristics of CH2NH sources. As a result of our survey, CH$_2$NH was detected in eight sources, including four new sources. The estimated fractional abundances were ~10$^8$ in Orion KL and G10.47+0.03, while they were ~10$^9$ towards the other sources. Our hydrogen recombination line and past studies suggest that CH$_2$NH-rich sources have less evolved HII regions. The less destruction rates by UV flux from the central star would be contributed to the high CH$_2$NH abundances towards CH$_2$NH-rich sources. Our gas-grain chemical simulations suggest that CH$_2$NH is mostly formed in the gas-phase by neutral-neutral reactions rather than the product of thermal evaporation from the dust surfaces.

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Taiki Suzuki, Masatoshi Ohishi, Tomoya Hirota, Masao Saito, Liton Majumdar, Valentine Wakelam. 2016-05-07. Survey Observations of a Possible Glycine Precursor, Methanimine (CH$_2$NH). https://doi.org/10.3847/0004-637x/825/1/79

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