Mapping Observations of complex organic molecules around Sagittarius B2 with ARO 12m telescope

Abstract

We performed high-sensitivity mapping observations of several complex organic molecules around Sagittarius B2 with ARO 12m telescope at 3-mm wavelength. Based on their spatial distribution, molecules can be classified as either "extended" that detected not only in Sgr B2(N) and Sgr B2(M), or "compact" that only detected toward or near to Sgr B2(N) and Sgr B2(M). The "extended" molecules including glycolaldehyde (CH2OHCHO), methyl formate (CH3OCHO), formic acid (t-HCOOH), ethanol (C2H5OH) and methyl amine (CH3NH2), while the "compact" molecules including dimethyl ether (CH3OCH3), ethyl cyanide (C2H5CN), and amino acetonitrile (H2NCH2CN). These "compact" molecules are likely produced under strong UV radiation, while "extended" molecules are likely formed under low-temperature, via gas-phase or grain surface reactions. The spatial distribution of "warm" CH2OHCHO at 89 GHz differ from the spatial distribution of "cold" CH2OHCHO observed at 13 GHz. We found evidence for an overabundance of CH2OHCHO compared to that expected from the gas-phase model, which indicates that grain-surface reactions are necessary to explain the origin of CH2OHCHO in Sagittarius B2. Grain-surface reactions are also needed to explain the correlation between the abundances of "cold" CH2OHCHO and C2H5OH. These results demonstrate the importance of grain-surface chemistry in the production of complex organic molecules.

11 pages, accepted by MNRAS

References in corpus (16)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• The ALMA Protostellar Interferometric Line Survey (PILS): First results from an unbiased submillimeter wavelength line survey of the Class 0 protostellar binary IRAS 16293-2422 with ALMA
• Testing grain-surface chemistry in massive hot-core regions
• Formation of complex organic molecules in cold objects: the role of gas phase reactions
• The largest oxigen bearing organic molecule repository
• Constraining the abundances of complex organics in the inner regions of solar-type protostars
• Experimental evidence for Glycolaldehyde and Ethylene Glycol formation by surface hydrogenation of CO molecules under dense molecular cloud conditions
• The Bolocam Galactic Plane Survey IV: 1.1 and 0.35 mm Dust Continuum Emission in the Galactic Center Region
• Organic Molecules in the Galactic Center. Hot Core Chemistry without Hot Cores
• The census of complex organic molecules in the solar type protostar IRAS16293-2422
• Phosphorus-bearing molecules in the Galactic Center
• Production of complex organic molecules: H-atom addition versus UV irradiation
• Spectral imaging of the Sagittarius B2 region in multiple 3-mm molecular lines with the Mopra telescope
• Widespread Presence of Glycolaldehyde and Ethylene Glycol Around Sagittarius B2
• ALMA Observations of the Spatial Distribution of three C${}_2$H${}_4$O${}_2$ Isomers towards Sgr B2(N)

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• Propionamide (C2H5CONH2): The largest peptide-like molecule in space
• Chemical modeling of the complex organic molecules in the extended region around Sagittarius B2
• The SKA as a prebiotic molecule detector