A high resolution study of complex organic molecules in hot cores

Abstract

We present the results of a line identification analysis using data from the IRAM Plateau de Bure Inferferometer, focusing on six massive star-forming hot cores: G31.41+0.31, G29.96-0.02, G19.61-0.23, G10.62-0.38, G24.78+0.08A1 and G24.78+0.08A2. We identify several transitions of vibrationally excited methyl formate (HCOOCH${}_3$) for the first time in these objects as well as transitions of other complex molecules, including ethyl cyanide (C${}_2$H${}_5$CN), and isocyanic acid (HNCO). We also postulate a detection of one transition of glycolaldehyde (CH${}_2$(OH)CHO) in two new hot cores. We find G29.96-0.02, G19.61-0.23, G24.78+0.08A1 and 24.78+0.08A2 to be chemically very similar. G31.41+0.31, however, is chemically different: it manifests a larger chemical inventory and has significantly larger column densities. We suggest that it may represent a different evolutionary stage to the other hot cores in the sample, or it may surround a star with a higher mass. We derive column densities for methyl formate in G31.41+0.31, using the rotation diagram method, of $\times$10${}^{17}$ cm${}^{-2}$ and a T${}_{rot}$ of $\sim$170 K. For G29.96-0.02, G24.78+0.08A1 and G24.78+0.08A2, glycolaldehyde, methyl formate and methyl cyanide all seem to trace the same material and peak at roughly the same position towards the dust emission peak. For G31.41+0.31, however, glycolaldehyde shows a different distribution to methyl formate and methyl cyanide and seems to trace the densest, most compact inner part of hot cores.

Accepted to MNRAS

References in corpus (7)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• Desorption From Interstellar Ices
• Infall of gas as the formation mechanism of stars up to 20 times more massive than the Sun
• Dust and gas emission in the prototypical hot core G29.96-0.02 at sub-arcsecond resolution
• Comparative study of complex N- and O-bearing molecules in hot molecular cores
• A sensitivity study of the neutral-neutral reactions C + C3 and C + C5 in cold dense interstellar clouds
• The hyperyoung HII region in G24.78+0.08 A1

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• ALMA Observations of the Spatial Distribution of three C${}_2$H${}_4$O${}_2$ Isomers towards Sgr B2(N)
• Fragmentation in the massive G31.41+0.31 protocluster
• Identification of the simplest sugar-like molecule glycolaldehyde towards the hot molecular core G358.93-0.03 MM1
• SPARKS II.: Complex organic molecules in accretion shocks around a hot core precursor
• High Resolution Observations of the Massive Protostar in IRAS18566+0408