In Table A.5 (page 17) of our original publication (Esplugueset al. 2016), the rate coefficient considered for the CO icephotodesorption was 2.2 × 10 ?15 s ?1 , however we should haveconsidered a coefficient of 3.67 × 10 ?10 s ?1 according to recentresults (Fayolle et al. 2011; Mu?oz-Caro et al. 2016). We alsoupdate here the values for the solid species H 2 O and H 2 CO con-sidering a coefficient of 3.67 × 10 ?11 s ?1 for both of them (seeTable 1) instead of 2.16 × 10 ?11 s ?1 . In particular, the photo-process reaction rate, R photo (cm ?3 s ?1 ), is calculated for thesecases asR photo = n i f ss k photo , (1)where n i is the number density of the photodissociated species,f ss is the self-shielding factor, and k photo (s ?1 ) is the photo-process rate coefficient as follows:k photo =χF Draine4n surf N layY i’ 2.16 × 10 ?8 χY i = 3.67 × 10 ?8 G 0 Y i = α i G 0 , following Chaparro-Molano & Kamp (2012). In expression (2),χ is the UV field strength (Draine 1978) 1 , and the pho-ton flux produced by this field per unit area is F Draine =1.921 × 10 8 cm ?2 s ?1 (Woitke et al. 2009). Furthermore, n surf =1.11 × 10 15 cm ?2 is the surface density of available absorptionsites per unit grain area assuming 3 ? separation between sites,N lay = 2 is the assumed number of ice layers that photonscan penetrate for photodesorption (Andersson et al. 2006; Arasaet al. 2010; Mu?oz-Caro et al. 2016), and Y i is the photodesorp-tion yield per photon (see Table 2).
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