Chemical Differentiation around Five Massive Protostars Revealed by ALMA -Carbon-Chain Species, Oxygen-/Nitrogen-Bearing Complex Organic Molecules-

Abstract

We present Atacama Large Millimeter/submillimeter Array Band 3 data toward five massive young stellar objects (MYSOs), and investigate relationships between unsaturated carbon-chain species and saturated complex organic molecules (COMs). An HC${}_5$N ($J=35-34$) line has been detected from three MYSOs, where nitrogen(N)-bearing COMs (CH${}_2$CHCN and CH${}_3$CH${}_2$CN) have been detected. The HC${}_5$N spatial distributions show compact features and match with a methanol (CH${}_3$OH) line with an upper-state energy around 300 K, which should trace hot cores. The hot regions are more extended around the MYSOs where N-bearing COMs and HC${}_5$N have been detected compared to two MYSOs without these molecular lines, while there are no clear differences in the bolometric luminosity and temperature. We run chemical simulations of hot-core models with a warm-up stage, and compare with the observational results. The observed abundances of HC${}_5$N and COMs show good agreements with the model at the hot-core stage with temperatures above 160 K. These results indicate that carbon-chain chemistry around the MYSOs cannot be reproduced by warm carbon-chain chemistry, and a new type of carbon-chain chemistry occurs in hot regions around MYSOs.

arXiv commentAccepted by the publication for The Astrophysical Journal Supplement Series, 32 pages,18 figures, 11 tables

References in corpus (37)

• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• The Cologne Database for Molecular Spectroscopy, CDMS, in the Virtual Atomic and Molecular Data Centre, VAMDC
• Our astrochemical heritage
• Non-thermal desorption from interstellar dust grains via exothermic surface reactions
• The 2014 KIDA network for interstellar chemistry
• ATLASGAL --- properties of a complete sample of Galactic clumps
• Gas and grain chemical composition in cold cores as predicted by the Nautilus 3-phase model
• Astrochemistry During the Formation of Stars
• Modeling Complex Organic Molecules in dense regions: Eley-Rideal and complex induced reaction
• Modeling the Lukewarm Corino Phase - is L1527 unique?
• Gravity Driven Magnetic Field at ~1000 au Scales in High-mass Star Formation
• SOLIS II. Carbon-chain growth in the Solar-type protocluster OMC2-FIR4
• Identification of pre-biotic molecules containing Peptide-like bond in a hot molecular core, G10.47+0.03
• ALMA reveals sequential high-mass star formation in the G9.62+0.19 complex
• Chemical survey toward young stellar objects in the Perseus molecular cloud complex
• In Search of Circumstellar Disks Around Young Massive Stars
• Carbon Chains and Methanol toward Embedded Protostars
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- VIII. A search for hot cores by using C${}_2$H${}_5$CN, CH${}_3$OCHO and CH${}_3$OH lines
• Modeling C-Shock Chemistry in Isolated Molecular Outflows
• Cyanopolyyne Chemistry around Massive Young Stellar Objects
• Survey Observations to Study Chemical Evolution from High-mass Starless Cores to High-mass Protostellar Objects I: HC3N and HC5N
• The Difference in Abundances between N-bearing and O-bearing Species in High-Mass Star-Forming Regions
• Methyl isocyanate CH3NCO: An important missing organic in current astrochemical networks
• A catalog of 44 GHz methanol masers in massive star-forming regions. IV. The high-mass protostellar object sample
• Survey Observations to Study Chemical Evolution from High-Mass Starless Cores to High-Mass Protostellar Objects II. HC${}_3$N and N${}_2$H${}^{+}$
• Chemical Diversity in Three Massive Young Stellar Objects associated with 6.7 GHz CH${}_3$OH Masers
• Identification of Methyl Isocyanate and Other Complex Organic Molecules in a Hot Molecular Core, G31.41+0.31
• Externally heated protostellar cores in the Ophiuchus star-forming region
• Observations of Cyanopolyynes toward Four High-Mass Star-Forming Regions Containing Hot Cores
• A NIKA view of two star-forming infrared dark clouds: Dust emissivity variations and mass concentration
• Chemical composition in the IRAS 16562--3959 high-mass star-forming region
• Interferometric Observations of Cyanopolyynes toward the G28.28-0.36 High-Mass Star-Forming Region
• DC${}_3$N observations towards high-mass star-forming regions
• New detections of HC${}_5$N toward hot cores associated with 6.7 GHz methanol masers
• Carbon Chain Chemistry in Hot-Core Regions around Three Massive Young Stellar Objects Associated with 6.7 GHz Methanol Masers
• Multiwavelength investigation of extended green object G19.88-0.53: Revealing a protocluster
• Chemical compositions in the vicinity of protostars in Ophiuchus

Cited by in corpus (4)

• Carbon-Chain Chemistry in the Interstellar Medium
• The SOFIA Massive (SOMA) Star Formation Q-band follow-up I. Carbon-chain chemistry of intermediate-mass protostars
• Velocity-resolved high-J CO emission from massive star-forming clumps
• CHemical Evolution in MassIve star-forming COres (CHEMICO). I. Evolution of the temperature structure