The ALMA Survey of 70 $\mu \mathrm{m}$ Dark High-mass Clumps in Early Stages (ASHES). VII: Chemistry of Embedded Dense Cores

Abstract

We present a study of chemistry toward 294 dense cores in 12 molecular clumps using the data obtained from the ALMA Survey of 70 $\mu \mathrm{m}$ dark High-mass clumps in Early Stages (ASHES). We identified 97 protostellar cores and 197 prestellar core candidates based on the detection of outflows and molecular transitions of high upper energy levels ($E_u/k>45$ K). The detection rate of the N${}_2$D${}^{+}$ emission toward the protostellar cores is 38%, which is higher than 9% for the prestellar cores, indicating that N${}_2$D${}^{+}$ does not exclusively trace prestellar cores. The detection rates of the DCO${}^{+}$ emission are 35% for the prestellar cores and 49% for the protostellar cores, which are higher than those of N${}_2$D${}^{+}$, implying that DCO${}^{+}$ appears more frequently than N${}_2$D${}^{+}$ in both prestellar and protostellar cores. Both N${}_2$D${}^{+}$ and DCO${}^{+}$ abundances appear to decrease from the prestellar to protostellar stage. The DCN, C${}_2$D and ${}^{13}$CS emission lines are rarely seen in the dense cores of early evolutionary phases. The detection rate of the H${}_2$CO emission toward dense cores is 52%, three times higher than that of CH${}_3$OH (17%). In addition, the H${}_2$CO detection rate, abundance, line intensities, and line widths increase with the core evolutionary status, suggesting that the H${}_2$CO line emission is sensitive to protostellar activity.

arXiv commentAccepted for Publication in ApJ. 36 pages, 15 figures, 5 tables. Table 5 available at https://github.com/ShanghuoLi/70-um-dark-high-mass-clumps

References in corpus (58)

• Astropy: A Community Python Package for Astronomy
• An atomic and molecular database for analysis of submillimetre line observations
• Cold Dark Clouds: The Initial Conditions for Star Formation
• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Structural Analysis of Molecular Clouds: Dendrograms
• Our astrochemical heritage
• How to Calculate Molecular Column Density
• Molecular ions in L1544. II. The ionization degree
• Testing grain-surface chemistry in massive hot-core regions
• Astrochemistry During the Formation of Stars
• Astrochemistry and compositions of planetary systems
• Chemistry in Infrared Dark Cloud Clumps: a Molecular Line Survey at 3 mm
• The ALMA Survey of 70 $\mu$m dark High-mass clumps in Early Stages (ASHES). I. Pilot Survey: Clump Fragmentation
• On the internal structure of starless cores. II. A molecular survey of L1498 and L1517B
• Complex Molecules in the L1157 Molecular Outflow
• Chemical modeling of L183 (= L134N) : an estimate of the ortho/para H2 ratio
• Depletion and low gas temperature in the L183 prestellar core : the N2H+ - N2D+ tool
• The H2CO abundance in the inner warm regions of low mass protostellar envelopes
• A molecular survey of outflow gas: velocity-dependent shock chemistry and the peculiar composition of the EHV gas
• Chemical evolution in the early phases of massive star formation. I
• Ingredients for Solar-like Systems: protostar IRAS 16293-2422 B versus comet 67P/Churyumov-Gerasimenko
• A Massive Prestellar Clump Hosting no High-Mass Cores
• New extended deuterium fractionation model: assessment at dense ISM conditions and sensitivity analysis
• pyspeckit: A spectroscopic analysis and plotting package
• H2CO and CH3OH abundances in the envelopes around low-mass protostars
• Chemical Evolution in High-Mass Star-Forming Regions: Results from the MALT90 Survey
• Distinct Chemical Regions in the "Prestellar" Infrared Dark Cloud (IRDC) G028.23-00.19
• Infall Signatures in a Prestellar Core embedded in the High-Mass 70 $\mu$m Dark IRDC G331.372-00.116
• The IRAM-30m line survey of the Horsehead PDR: IV. Comparative chemistry of H2CO and CH3OH
• High sensitivity maps of molecular ions in L1544: I. Deuteration of N2H+ and HCO+ and first evidence of N2D+ depletion
• Molecular outflows within the filamentary infrared dark cloud G34.43+0.24
• The ALMA Survey of 70 $\mu \mathrm{m}$ Dark High-mass Clumps in Early Stages (ASHES). II: Molecular Outflows in the Extreme Early Stages of Protocluster Formation
• Chemical evolution in the early phases of massive star formation II: Deuteration
• A MALT90 study of the chemical properties of massive clumps and filaments of infrared dark clouds
• A Hunt for Massive Starless Cores
• Diversity of chemistry and excitation conditions in the high-mass star forming complex W33
• 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
• Organic species in Infrared Dark Clouds
• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). IV. Star formation signatures in G023.477
• Deuterium Fractionation as an Evolutionary Probe in the Infrared Dark Cloud G28.34+0.06
• Establishing the evolutionary timescales of the massive star formation process through chemistry
• A SiO J = 5 - 4 Survey Toward Massive Star Formation Regions
• ALMA Observations of Massive Clouds in the Central Molecular Zone: Ubiquitous Protostellar Outflows
• Survey of ortho-H${}_2$D${}^{+}$ in high-mass star-forming regions
• Widespread deuteration across the IRDC G035.39-00.33
• An Interferometric View of H-MM1. I. Direct Observation of NH3 Depletion
• Identification of prestellar cores in high-mass star forming clumps via ${\mathrm{H}}_2{\mathrm{D}}^{+}$ observations with ALMA
• On the size of the CO-depletion radius in the IRDC G351.77-0.51
• The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VI. The core-scale CO-depletion
• The chemical structure of young high-mass star-forming clumps: (II) parsec-scale CO depletion and deuterium fraction of $\mathrm{HC}{\mathrm{O}}^{+}$
• Chemistry of the High-Mass Protostellar Molecular Clump IRAS 16562-3959
• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). V. Deuterated Molecules in the 70 $\mu$m dark IRDC G14.492-00.139
• H2CO and CH3OH maps of the Orion Bar photodissociation region
• A timeline for massive star-forming regions via combined observation of o-H${}_2$D${}^{+}$ and N${}_2$D${}^{+}$
• The ALMA Survey of 70$\mu$m Dark High-mass Clumps in Early Stages (ASHES) III. A Young Molecular Outflow Driven by a Decelerating Jet
• A Low-mass Cold and Quiescent Core Population in a Massive Star Protocluster
• Millimeter Spectral Line Mapping Observations Toward Four Massive Star Forming HII Regions

Cited by in corpus (10)

• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). IX. Physical Properties and Spatial Distribution of Cores in IRDCs
• The ALMA Survey of 70 μm Dark High-mass Clumps in Early Stages (ASHES). VIII. Dynamics of Embedded Dense Cores
• ALMA-IMF. VII. First release of the full spectral line cubes: Core kinematics traced by DCN J=(3-2)
• The Cygnus Allscale Survey of Chemistry and Dynamical Environments: CASCADE. II. A detailed kinematic analysis of the DR21 Main outflow
• ALMAGAL IV. Morphological comparison of molecular and thermal dust emission using the histogram of oriented gradients (HOG) method
• The ALMA Survey of 70 $\mu$m Dark High-mass Clumps in Early Stages (ASHES). XII. Unanchored Forked Stream in the Propagating Path of a Protostellar Outflow
• Impact of cosmic-ray propagation on the chemistry and ionisation fraction of dark clouds
• Molecular deuterations in massive Starless Clump Candidates
• DCO${}^{+}$ and DCN 1-0 survey toward a sample of Planck cold clumps
• The Cygnus Allscale Survey of Chemistry and Dynamical Environments: CASCADE III. The large scale distribution of DCO+, DNC and DCN in the DR21 filament