Table 3.

Calculated abundances of CH₃O relative to methanol at 10 K considering gas-phase formation via reaction (1)

Grain surface source of CH3O	nH (molecule cm−3	k1(10 K) (cm3 molecule−1 s−1)	n(CH3O)/n(CH3OH)	time (yr)	Reference
NO	2 × 104	1.1 × 10−10	(0.08 – 2) × 10−3	105 – 107	This work
NO	1 × 105	1.1 × 10−10	(0.1 – 0.6) × 10−3	105 – 107	This work
YES	2 × 104	3 × 10−10	~ 5000 × 10−3	105 – 107	Acharyya et al. (2015)
YES	1 × 105	4 × 10−11	(10 – 100) × 10−3	105 – 107	Ruaud et al. (2015)
NO	6 × 104	3 × 10−10	~ 40 × 10−3	~ 105	Balucani et al. (2015)
NO	1 × 105	4 × 10−11	(2 – 10) × 10−3	105 – 106	Vasyunin & Herbst (2013)
YES	1 × 105	4 × 10−11	(0.3 – 50) × 10−3	105 – 106	Vasyunin & Herbst (2013)

Note. — The observed n(CH₃O)/n(CH₃OH) in B1-b is ~ 3 × 10⁻³ (Öberg et al. 2010; Cernicharo et al. 2012).