C18O depletion in starless cores in Taurus

Amanda Brady Ford, Yancy L Shirley

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We present here findings for C18O depletion in eight starless cores in Taurus: TMC-2, L1498, L1512, L1489, L1517B, L1521E, L1495A-S, and L1544. We compare observations of the C18O J = 2-1 transition taken with the ALMA prototype receiver on the Heinrich Hertz Submillimeter Telescope to results of radiative transfer modeling using RATRAN. We use temperature and density profiles calculated from dust continuum radiative transfer models to model the C18O emission. We present modeling of three cores, TMC-2, L1489, and L1495A-S, which have not been modeled before, and compare our results for the five cores with published models. We find that all of the cores but one, L1521E, are substantially depleted. We also find that varying the temperature profiles of these model cores has a discernable effect, and varying the central density has an even larger effect. We find no trends with depletion radius or depletion fraction with the density or temperature of these cores, suggesting that the physical structure alone is insufficient to fully constrain evolutionary state. We are able to place tighter constraints on the radius at which C18O is depleted than the absolute fraction of depletion. As the timeline of chemical depletion depends sensitively on the fraction of depletion, this difficulty in constraining depletion fraction makes comparison with other timescales, such as the free-fall timescale, very difficult.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume728
Issue number2
DOIs
StatePublished - Feb 20 2011

Fingerprint

depletion
radiative transfer
timescale
temperature profiles
temperature profile
modeling
temperature
free fall
radii
dust
receivers
prototypes
telescopes
continuums
trends
profiles
effect

Keywords

  • ISM: abundances
  • ISM: clouds
  • ISM: individual objects (TMC2, L1498, L1512, L1489, L1517B, L1521E, L1495AS, L1544)
  • ISM: molecules
  • Stars: formation

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

C18O depletion in starless cores in Taurus. / Ford, Amanda Brady; Shirley, Yancy L.

In: Astrophysical Journal, Vol. 728, No. 2, 20.02.2011.

Research output: Contribution to journalArticle

@article{c4a26d31689f4bef9bb34bf4f69acbc0,
title = "C18O depletion in starless cores in Taurus",
abstract = "We present here findings for C18O depletion in eight starless cores in Taurus: TMC-2, L1498, L1512, L1489, L1517B, L1521E, L1495A-S, and L1544. We compare observations of the C18O J = 2-1 transition taken with the ALMA prototype receiver on the Heinrich Hertz Submillimeter Telescope to results of radiative transfer modeling using RATRAN. We use temperature and density profiles calculated from dust continuum radiative transfer models to model the C18O emission. We present modeling of three cores, TMC-2, L1489, and L1495A-S, which have not been modeled before, and compare our results for the five cores with published models. We find that all of the cores but one, L1521E, are substantially depleted. We also find that varying the temperature profiles of these model cores has a discernable effect, and varying the central density has an even larger effect. We find no trends with depletion radius or depletion fraction with the density or temperature of these cores, suggesting that the physical structure alone is insufficient to fully constrain evolutionary state. We are able to place tighter constraints on the radius at which C18O is depleted than the absolute fraction of depletion. As the timeline of chemical depletion depends sensitively on the fraction of depletion, this difficulty in constraining depletion fraction makes comparison with other timescales, such as the free-fall timescale, very difficult.",
keywords = "ISM: abundances, ISM: clouds, ISM: individual objects (TMC2, L1498, L1512, L1489, L1517B, L1521E, L1495AS, L1544), ISM: molecules, Stars: formation",
author = "Ford, {Amanda Brady} and Shirley, {Yancy L}",
year = "2011",
month = "2",
day = "20",
doi = "10.1088/0004-637X/728/2/144",
language = "English (US)",
volume = "728",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",

}

TY - JOUR

T1 - C18O depletion in starless cores in Taurus

AU - Ford, Amanda Brady

AU - Shirley, Yancy L

PY - 2011/2/20

Y1 - 2011/2/20

N2 - We present here findings for C18O depletion in eight starless cores in Taurus: TMC-2, L1498, L1512, L1489, L1517B, L1521E, L1495A-S, and L1544. We compare observations of the C18O J = 2-1 transition taken with the ALMA prototype receiver on the Heinrich Hertz Submillimeter Telescope to results of radiative transfer modeling using RATRAN. We use temperature and density profiles calculated from dust continuum radiative transfer models to model the C18O emission. We present modeling of three cores, TMC-2, L1489, and L1495A-S, which have not been modeled before, and compare our results for the five cores with published models. We find that all of the cores but one, L1521E, are substantially depleted. We also find that varying the temperature profiles of these model cores has a discernable effect, and varying the central density has an even larger effect. We find no trends with depletion radius or depletion fraction with the density or temperature of these cores, suggesting that the physical structure alone is insufficient to fully constrain evolutionary state. We are able to place tighter constraints on the radius at which C18O is depleted than the absolute fraction of depletion. As the timeline of chemical depletion depends sensitively on the fraction of depletion, this difficulty in constraining depletion fraction makes comparison with other timescales, such as the free-fall timescale, very difficult.

AB - We present here findings for C18O depletion in eight starless cores in Taurus: TMC-2, L1498, L1512, L1489, L1517B, L1521E, L1495A-S, and L1544. We compare observations of the C18O J = 2-1 transition taken with the ALMA prototype receiver on the Heinrich Hertz Submillimeter Telescope to results of radiative transfer modeling using RATRAN. We use temperature and density profiles calculated from dust continuum radiative transfer models to model the C18O emission. We present modeling of three cores, TMC-2, L1489, and L1495A-S, which have not been modeled before, and compare our results for the five cores with published models. We find that all of the cores but one, L1521E, are substantially depleted. We also find that varying the temperature profiles of these model cores has a discernable effect, and varying the central density has an even larger effect. We find no trends with depletion radius or depletion fraction with the density or temperature of these cores, suggesting that the physical structure alone is insufficient to fully constrain evolutionary state. We are able to place tighter constraints on the radius at which C18O is depleted than the absolute fraction of depletion. As the timeline of chemical depletion depends sensitively on the fraction of depletion, this difficulty in constraining depletion fraction makes comparison with other timescales, such as the free-fall timescale, very difficult.

KW - ISM: abundances

KW - ISM: clouds

KW - ISM: individual objects (TMC2, L1498, L1512, L1489, L1517B, L1521E, L1495AS, L1544)

KW - ISM: molecules

KW - Stars: formation

UR - http://www.scopus.com/inward/record.url?scp=84891228742&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84891228742&partnerID=8YFLogxK

U2 - 10.1088/0004-637X/728/2/144

DO - 10.1088/0004-637X/728/2/144

M3 - Article

VL - 728

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

ER -