Speaker
Description
Complex molecules are commonly detected in high- and low-mass star
forming regions. In the past years, however, complex species have been
detected in unexpected environments like photo-dominated regions
(PDRs). The great sensitivity and resolution power of ALMA has also
allowed us to start detecting and resolving complex species in
protopanetary disks.
I will show recent observations of complex organics in the
prototypical PDR, the Horsehead nebula. We detect H$_2$CO, CH$_3$OH,
HCOOH, CH$_2$CO, CH$_3$CHO, CH$_3$CCH, CH$_3$CN and HC$_3$N. We have
mapped the emission of the COMs, and find that some of them present
enhanced abundances in the UV-exposed PDR compared to the UV-shielded
dense core. This shows the importance of the interplay between the
solid and gas phase chemistry in the formation of (complex) organic
species, and confirm that ice photo-processing is an efficient
mechanism to release frozen species into the gas phase.
I will also show recent observations of complex organic molecules in
protoplanetary disks. We have detected CH$_3$CN and HC$_3$N in several
disks, and find consistent relative abundances between our disk
sample, protostellar envelopes and comets. I will also present new
spatially resolved ALMA observations of H$_2$CO, a key intermediate in
the formation of more complex species in ices. Contrary to CH$_3$OH,
H$_2$CO is readily observable in disks and could thus be used to trace
the cold organic reservoir in disks.
