Emission from the 212 − 111 line of H2CO has been detected and marginally resolved toward LkCa15 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, and the line intensity profile is less centrally peaked than that for CO. Similar behavior is observed in other organic gaseous molecules in...

The protostar B335 was observed in the 1.3 mm continuum and in the H2CO 312 → 211 line with an angular resolution of about 8. The mass of the inner envelope detected by the dust continuum emission is about 0.02 M⊙. The H2CO spectrum at the protostellar position shows a blue-skewed double peak profile, suggesting that the kinematics of the inner envelope is dominated by infall motion. When the b...

The absolute vacuum ultraviolet (VUV) photoionization spectra of the hydroperoxyl radical (HO2), hydrogen peroxide (H2O2), and formaldehyde (H2CO) have been measured from their first ionization thresholds to 12.008 eV. HO2, H2O2, and H2CO were generated from the oxidation of methanol initiated by pulsed-laser-photolysis of Cl2 in a low-pressure slow flow reactor. Reactants, intermediates, and p...

The use of a compact gas sensor based on cw difference-frequency generation in periodically poled LiNbO3 for on-line absorption measurements of H2CO, CH4, and H2O near 3.5 μm is reported. Formaldehyde levels of 30 ppb, corresponding to absorptions of 2×10−4 have been measured using absorption spectroscopy. In this paper we report specifically the performance of this sensor as part of the 1997 L...

Formaldehyde (H2CO) is an important precursor to organics like methanol (CH3OH). It understand the conditions that produce H2CO and prebiotic molecules during star planet formation. possesses both gas-phase solid-state formation pathways, involving either UV-produced radical precursors or CO ice cold (?20 K) dust grains. To which pathway dominates, gaseous H2CO's ortho-to-para ratio (OPR) has b...

We report the detection of CN, HCN, HNC, CS, HCO+, C2H and H2CO (ortho and para) in the protoplanetary disks of DM Tau and GG Tau. For the first time organic molecules are observed in objects representative of the presolar nebula. These molecules are underabundant with respect to the standard dense clouds. The depletions in the “outer” disk of DM Tau (100 < r < 900 AU), derived from the line in...

Nuclear spin isomers were discovered in the late 1920s when ortho and para H2 were separated by deep cooling of hydrogen gas. This technique was successful because of extremely large gap between the ortho and para states in H2. Investigations of heavier isomers were not possible to perform until recently because of the lack of appropriate enrichment methods. First separation of heavy molecules ...

Observations of two H2CO (303−202 and 321−220) lines and continuum emission at 1.3 mm towards Sgr B2(N) and Sgr B2(M) have been carried out with the SMA. The mosaic maps of Sgr B2(N) and Sgr B2(M) in both continuum and lines show a complex distribution of dust and molecular gas in both clumps and filaments surrounding the compact star formation cores. We have observed a decelerating outflow ori...