Observations of a Possible Glycine Precursor, Methanimine (CH2NH)
We conducted survey observations of a glycine precursor, methanimine or methylenimine (CH2NH), 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 CH2NH sources and to better understand the characteristics of CH2NH sources.
As a result of our survey, CH2NH was detected in eight sources, including four new sources. The estimated fractional abundances were ~108 in Orion KL and G10.47+0.03, while they were ~109 towards the other sources. Our hydrogen recombination line and past studies suggest that CH2NH-rich sources have less evolved HII regions. The less destruction rates by UV flux from the central star would be contributed to the high CH2NH abundances towards CH2NH-rich sources. Our gas-grain chemical simulations suggest that CH2NH is mostly formed in the gas-phase by neutral-neutral reactions rather than the product of thermal evaporation from the dust surfaces.
Taiki Suzuki, Masatoshi Ohishi, Tomoya Hirota, Masao Saito, Liton Majumdar, Valentine Wakelam
(Submitted on 7 May 2016)
Comments: 49 pages, 12 figures, accepted to ApJ
Subjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:1605.02161 [astro-ph.GA] (or arXiv:1605.02161v1 [astro-ph.GA] for this version)
Submission history
From: Taiki Suzuki
[v1] Sat, 7 May 2016 09:15:11 GMT (4593kb)
http://arxiv.org/abs/1605.02161
