An. Witt et al., K'-BAND OBSERVATIONS OF THE EVIL EYE GALAXY - ARE THE OPTICAL AND NEAR-INFRARED DUST ALBEDOS IDENTICAL, The Astrophysical journal, 427(1), 1994, pp. 227-231
New measurements of the reduction of the V-band surface brightness acr
oss the prominent dust feature in the galaxy NGC 4826 are compared wit
h corresponding increases in the V-K' color within the context of radi
ative transfer models invoking both absorption and scattering. The K'-
band surface brightness is found to be higher than expected from stand
ard dust models. We interpret the difference as resulting from a high
effective dust albedo at K', with a likely value in excess of 0.8, pro
vided the near-IR extinction curve in NGC 4826 is identical to the Gal
actic one. The high effective albedo may result from scattering by dus
t with a maximum grain size at least twice as large as assumed by stan
dard models, a conclusion already indirectly hinted at by recent studi
es of dusty star-forming regions and reflection nebulae. At least part
of the high effective albedo at K' may result from near-IR nonequilib
rium continuum emission attributable to very small grains.