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Evolution of CO lines in time-dependent models of protostellar disk formation
- Source :
- Astronomy & Astrophysics, 555, A45, Astronomy & astrophysics, 555:A45. EDP Sciences
- Publication Year :
- 2013
- Publisher :
- EDP Sciences, 2013.
-
Abstract
- (Abridged) Star and planet formation theories predict an evolution in the density, temperature, and velocity structure as the envelope collapses and forms an accretion disk. The aim of this work is to model the evolution of the molecular excitation, line profiles, and related observables during low-mass star formation. Specifically, the signatures of disks during the deeply embedded stage are investigated. Semi-analytic 2D axisymmetric models have been used to describe the evolution of the density, stellar mass, and luminosity from the pre-stellar to the T-Tauri phase. A full radiative transfer calculation is carried out to accurately determine the time-dependent dust temperatures and CO abundance structure. We present non-LTE near-IR, FIR, and submm lines of CO have been simulated at a number of time steps. In contrast to the dust temperature, the CO excitation temperature derived from submm/FIR lines does not vary during the protostellar evolution, consistent with C18O observations obtained with Herschel and from ground-based telescopes. The near-IR spectra provide complementary information to the submm lines by probing not only the cold outer envelope but also the warm inner region. The near-IR high-J (>8) absorption lines are particularly sensitive to the physical structure of the inner few AU, which does show evolution. High signal-to-noise ratio subarcsec resolution data with ALMA are needed to detect the presence of small rotationally supported disks during the Stage 0 phase and various diagnostics are discussed.<br />Accepted for publication in A&A, 17 pages with appendix; 14 figures
- Subjects :
- 010504 meteorology & atmospheric sciences
Stellar mass
FOS: Physical sciences
SPECTRAL ENERGY-DISTRIBUTIONS
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Excitation temperature
01 natural sciences
Spectral line
methods: numerical
Luminosity
accretion
SUBMILLIMETER ARRAY
HL TAURI
Planet
CIRCUMSTELLAR DISKS
0103 physical sciences
Radiative transfer
Astrophysics::Solar and Stellar Astrophysics
010303 astronomy & astrophysics
Solar and Stellar Astrophysics (astro-ph.SR)
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
Line (formation)
STAR-FORMING REGIONS
Physics
accretion, accretion disks
stars: formation
LOW-MASS PROTOSTARS
astrochemistry
Star formation
accretion disks
Astronomy and Astrophysics
MAGNETIC BRAKING CATASTROPHE
YOUNG STELLAR OBJECTS
Astrophysics - Astrophysics of Galaxies
PROTOPLANETARY DISK
Astrophysics - Solar and Stellar Astrophysics
radiative transfer
13. Climate action
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
MOLECULAR-LINE
Astrophysics::Earth and Planetary Astrophysics
Subjects
Details
- ISSN :
- 14320746 and 00046361
- Volume :
- 555
- Database :
- OpenAIRE
- Journal :
- Astronomy & Astrophysics
- Accession number :
- edsair.doi.dedup.....5bedf4bead526add8dbf4f54c5504d6b