摘要：In Table A.5 (page 17) of our original publication (Esplugues
et al. 2016), the rate coefficient considered for the CO ice
photodesorption was 2.2 × 10 −15 s −1 , however we should have
considered a coefficient of 3.67 × 10 −10 s −1 according to recent
results (Fayolle et al. 2011; Muñoz-Caro et al. 2016). We also
update 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 (see
Table 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 these
cases as
R 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 Draine
4n surf N lay
Y 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 absorption
sites per unit grain area assuming 3 Å separation between sites,
N lay = 2 is the assumed number of ice layers that photons
can penetrate for photodesorption (Andersson et al. 2006; Arasa
et al. 2010; Muñoz-Caro et al. 2016), and Y i is the photodesorp-
tion yield per photon (see Table 2).
关键词：astrochemistry;ISM: abundances;photon-dominated region (PDR);errata, addenda
