Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A

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Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A. / Harsono, D.; van der Wiel, M. H. D.; Bjerkeli, P.; Ramsey, J. P.; Calcutt, H.; Kristensen, L. E.; Jorgensen, J. K.

In: Astronomy & Astrophysics, Vol. 646, A72, 12.02.2021.

Research output: Contribution to journalJournal articleResearchpeer-review

Harvard

Harsono, D, van der Wiel, MHD, Bjerkeli, P, Ramsey, JP, Calcutt, H, Kristensen, LE & Jorgensen, JK 2021, 'Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A', Astronomy & Astrophysics, vol. 646, A72. https://doi.org/10.1051/0004-6361/202038697

APA

Harsono, D., van der Wiel, M. H. D., Bjerkeli, P., Ramsey, J. P., Calcutt, H., Kristensen, L. E., & Jorgensen, J. K. (2021). Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A. Astronomy & Astrophysics, 646, [A72]. https://doi.org/10.1051/0004-6361/202038697

Vancouver

Harsono D, van der Wiel MHD, Bjerkeli P, Ramsey JP, Calcutt H, Kristensen LE et al. Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A. Astronomy & Astrophysics. 2021 Feb 12;646. A72. https://doi.org/10.1051/0004-6361/202038697

Author

Harsono, D. ; van der Wiel, M. H. D. ; Bjerkeli, P. ; Ramsey, J. P. ; Calcutt, H. ; Kristensen, L. E. ; Jorgensen, J. K. / Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A. In: Astronomy & Astrophysics. 2021 ; Vol. 646.

Bibtex

@article{d9fe186ea716438383e0ad607123afff,
title = "Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A",
abstract = "Context. Physical processes that govern the star and planet formation sequence influence the chemical composition and evolution of protoplanetary disks. Recent studies allude to an early start to planet formation already during the formation of a disk. To understand the chemical composition of protoplanets, we need to constrain the composition and structure of the disks from whence they are formed.Aims. We aim to determine the molecular abundance structure of the young disk around the TMC1A protostar on au scales in order to understand its chemical structure and any possible implications for disk formation.Methods. We present spatially resolved Atacama Large Millimeter/submillimeter Array observations of CO, HCO+, HCN, DCN, and SO line emission, as well as dust continuum emission, in the vicinity of TMC1A. Molecular column densities are estimated both under the assumption of optically thin emission from molecules in local thermodynamical equilibrium (LTE) as well as through more detailed non-LTE radiative transfer calculations.Results. Resolved dust continuum emission from the disk is detected between 220 and 260 GHz. Rotational transitions from HCO+, HCN, and SO are also detected from the inner 100 au region. We further report on upper limits to vibrational HCN upsilon (2) = 1, DCN, and N2D+ lines. The HCO+ emission appears to trace both the Keplerian disk and the surrounding infalling rotating envelope. HCN emission peaks toward the outflow cavity region connected with the CO disk wind and toward the red-shifted part of the Keplerian disk. From the derived HCO+ abundance, we estimate the ionization fraction of the disk surface, and find values that imply that the accretion process is not driven by the magneto-rotational instability. The molecular abundances averaged over the TMC1A disk are similar to its protostellar envelope and other, older Class II disks. We meanwhile find a discrepancy between the young disk's molecular abundances relative to Solar System objects.Conclusions. Abundance comparisons between the disk and its surrounding envelope for several molecular species reveal that the bulk of planet-forming material enters the disk unaltered. Differences in HCN and H2O molecular abundances between the disk around TMC1A, Class II disks, and Solar System objects trace the chemical evolution during disk and planet formation.",
keywords = "stars: formation, stars: protostars, ISM: abundances, astrochemistry, ISM: individual objects: TMC1A, protoplanetary disks",
author = "D. Harsono and {van der Wiel}, {M. H. D.} and P. Bjerkeli and Ramsey, {J. P.} and H. Calcutt and Kristensen, {L. E.} and Jorgensen, {J. K.}",
year = "2021",
month = feb,
day = "12",
doi = "10.1051/0004-6361/202038697",
language = "English",
volume = "646",
journal = "Astronomy & Astrophysics",
issn = "0004-6361",
publisher = "E D P Sciences",

}

RIS

TY - JOUR

T1 - Resolved molecular line observations reveal an inherited molecular layer in the young disk around TMC1A

AU - Harsono, D.

AU - van der Wiel, M. H. D.

AU - Bjerkeli, P.

AU - Ramsey, J. P.

AU - Calcutt, H.

AU - Kristensen, L. E.

AU - Jorgensen, J. K.

PY - 2021/2/12

Y1 - 2021/2/12

N2 - Context. Physical processes that govern the star and planet formation sequence influence the chemical composition and evolution of protoplanetary disks. Recent studies allude to an early start to planet formation already during the formation of a disk. To understand the chemical composition of protoplanets, we need to constrain the composition and structure of the disks from whence they are formed.Aims. We aim to determine the molecular abundance structure of the young disk around the TMC1A protostar on au scales in order to understand its chemical structure and any possible implications for disk formation.Methods. We present spatially resolved Atacama Large Millimeter/submillimeter Array observations of CO, HCO+, HCN, DCN, and SO line emission, as well as dust continuum emission, in the vicinity of TMC1A. Molecular column densities are estimated both under the assumption of optically thin emission from molecules in local thermodynamical equilibrium (LTE) as well as through more detailed non-LTE radiative transfer calculations.Results. Resolved dust continuum emission from the disk is detected between 220 and 260 GHz. Rotational transitions from HCO+, HCN, and SO are also detected from the inner 100 au region. We further report on upper limits to vibrational HCN upsilon (2) = 1, DCN, and N2D+ lines. The HCO+ emission appears to trace both the Keplerian disk and the surrounding infalling rotating envelope. HCN emission peaks toward the outflow cavity region connected with the CO disk wind and toward the red-shifted part of the Keplerian disk. From the derived HCO+ abundance, we estimate the ionization fraction of the disk surface, and find values that imply that the accretion process is not driven by the magneto-rotational instability. The molecular abundances averaged over the TMC1A disk are similar to its protostellar envelope and other, older Class II disks. We meanwhile find a discrepancy between the young disk's molecular abundances relative to Solar System objects.Conclusions. Abundance comparisons between the disk and its surrounding envelope for several molecular species reveal that the bulk of planet-forming material enters the disk unaltered. Differences in HCN and H2O molecular abundances between the disk around TMC1A, Class II disks, and Solar System objects trace the chemical evolution during disk and planet formation.

AB - Context. Physical processes that govern the star and planet formation sequence influence the chemical composition and evolution of protoplanetary disks. Recent studies allude to an early start to planet formation already during the formation of a disk. To understand the chemical composition of protoplanets, we need to constrain the composition and structure of the disks from whence they are formed.Aims. We aim to determine the molecular abundance structure of the young disk around the TMC1A protostar on au scales in order to understand its chemical structure and any possible implications for disk formation.Methods. We present spatially resolved Atacama Large Millimeter/submillimeter Array observations of CO, HCO+, HCN, DCN, and SO line emission, as well as dust continuum emission, in the vicinity of TMC1A. Molecular column densities are estimated both under the assumption of optically thin emission from molecules in local thermodynamical equilibrium (LTE) as well as through more detailed non-LTE radiative transfer calculations.Results. Resolved dust continuum emission from the disk is detected between 220 and 260 GHz. Rotational transitions from HCO+, HCN, and SO are also detected from the inner 100 au region. We further report on upper limits to vibrational HCN upsilon (2) = 1, DCN, and N2D+ lines. The HCO+ emission appears to trace both the Keplerian disk and the surrounding infalling rotating envelope. HCN emission peaks toward the outflow cavity region connected with the CO disk wind and toward the red-shifted part of the Keplerian disk. From the derived HCO+ abundance, we estimate the ionization fraction of the disk surface, and find values that imply that the accretion process is not driven by the magneto-rotational instability. The molecular abundances averaged over the TMC1A disk are similar to its protostellar envelope and other, older Class II disks. We meanwhile find a discrepancy between the young disk's molecular abundances relative to Solar System objects.Conclusions. Abundance comparisons between the disk and its surrounding envelope for several molecular species reveal that the bulk of planet-forming material enters the disk unaltered. Differences in HCN and H2O molecular abundances between the disk around TMC1A, Class II disks, and Solar System objects trace the chemical evolution during disk and planet formation.

KW - stars: formation

KW - stars: protostars

KW - ISM: abundances

KW - astrochemistry

KW - ISM: individual objects: TMC1A

KW - protoplanetary disks

U2 - 10.1051/0004-6361/202038697

DO - 10.1051/0004-6361/202038697

M3 - Journal article

VL - 646

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

SN - 0004-6361

M1 - A72

ER -

ID: 258272590