Interferometric Observations of Formaldehyde in the Protoplanetary Disk   around LkCa15
  Emission from the $2_{12}-1_{11}$ line of H$_2$CO has been detected and marginally resolved toward LkCa15 by the Nobeyama Millimeter Array. The column density of H$_2$CO is higher than that observed in DM Tau and than predicted by theoretical models of disk chemistry; also the line-intensity profile is less centrally peaked than that for CO. A similar behavior is observed in other organic gaseous molecules in the LkCa 15 disk. 
Yuri Aikawa, Munetake Momose, Wing-Fai Thi, Gerd-Jan van Zadelhoff,   Chunhua Qi, Geoffrey A. Blake, Ewine F. van Dishoeck