Interferometric observations of formaldehyde in the protoplanetary disk around LkCa 15

Emission from the 2(12)-1(11) line of H2CO has been detected and marginally resolved toward LkCa 15 by the Nobeyama Millimeter Array. The column density of H2CO 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.