Decrease of the organic deuteration during the evolution of Sun-like protostars: the case of SVS13-A

Abstract

We present the results of formaldehyde and methanol deuteration measurements towards the Class I low-mass protostar SVS13-A, in the framework of the IRAM 30-m ASAI (Astrochemical Surveys At IRAM) project. We detected emission lines of formaldehyde, methanol, and their deuterated forms (HDCO, D2CO, CHD2OH, CH3OD) with Eup up to 276 K. The formaldehyde analysis indicates Tkin = 15 - 30 K, n (H2) >= 10^6 cm^-3, and a size of about 1200 AU suggesting an origin in the protostellar envelope. For methanol we find two components: (i) a high temperature (Tkin = 80 K) and very dense (> 10^8 cm^-3}) gas from a hot corino (radius about 35 AU), and (ii) a colder Tkin <= 70 K) and more extended (radius about 350 AU) region. The deuterium fractionation is 9 10^-2 for HDCO, 4 10^-3 for D2CO, and 2 - 7 10^-3 for CH2DOH, up to two orders of magnitude lower than the values measured in Class 0 sources. We derive also formaldehyde deuteration in the outflow: 4 10^-3, in agreement with what found in the L1157-B1 protostellar shock. Finally, we estimate [CH2DOH]/[CH3OD] about 2. The decrease of deuteration in the Class I source SVS13-A with respect to Class 0 sources can be explained by gas-phase processes. Alternatively, a lower deuteration could be the effect of a gradual collapse of less deuterated external shells of the protostellar evelope. The present measurements fill in the gap between prestellar cores and protoplanetary disks in the context of organics deuteration measurements.

MNRASS, in press, 13 pages, 10 figures

References in corpus (26)

• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• Our astrochemical heritage
• Unveiling the Circumstellar Envelope and Disk: A Sub-Arcsecond Survey of Circumstellar Structures
• The VLA Nascent Disk and Multiplicity Survey of Perseus Protostars (VANDAM). II. Multiplicity of Protostars in the Perseus Molecular Cloud
• First detection of triply-deuterated methanol
• Astrometry of Water Maser Sources in Nearby Molecular Clouds with VERA - II. SVS 13 in NGC 1333
• Detection of doubly-deuterated methanol in the solar-type protostar IRAS16293-2422
• The chemical history of molecules in circumstellar disks. I. Ices
• Exploring Molecular Complexity with ALMA (EMoCA): Deuterated complex organic molecules in Sagittarius B2(N2)
• CO Depletion and Deuterium Fractionation in Prestellar Cores
• The importance of the ortho:para H2 ratio for the deuteration of molecules during pre-protostellar collapse
• Weeds: a CLASS extension for the analysis of millimeter and sub-millimeter spectral surveys
• Testing grain surface chemistry : a survey of deuterated formaldehyde and methanol in low-mass Class 0 protostars
• Shedding light on the formation of the pre-biotic molecule formamide with ASAI
• Multilayer formation and evaporation of deuterated ices in prestellar and protostellar cores
• Deuterated methanol in the pre-stellar core L1544
• Formaldehyde and methanol deuteration in protostars: fossiles from a past fast high density pre-collapse phase
• Water ice deuteration: a tracer of the chemical history of protostars
• Theoretical HDO emission from low-mass protostellar envelopes
• Detection of DCO+ in a circumstellar disk
• Deuterated molecules in DM Tau: DCO+, but no HDO
• IRAM-PdBI Observations of Binary Protostars I: The Hierarchical System SVS13 in NGC1333
• Evidence for Multiple Pathways to Deuterium Enhancements in Protoplanetary Disks
• Detection of a hot core in the intermediate-mass (IM) Class 0 protostar NGC 7129--FIRS2
• An Unbiased Spectral Line Survey toward R CrA IRS7B in the 345 GHz Window with ASTE
• Hot and dense water in the inner 25 AU of SVS13-A

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• A Survey of CH2DOH Towards Starless and Prestellar Cores in the Taurus Molecular Cloud
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• Successive deuteration in low-mass star-forming regions: the case of D${}_2$-methanol (CHD${}_2$OH) in IRAS 16293-2422
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• Observations and chemical modeling of the isotopologues of formaldehyde and the cations of formyl and protonated formaldehyde in the hot molecular core G331.512-0.103
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