On the reliability of protostellar disc mass measurements and the existence of fragmenting discs

Autor(en)

Eduard Vorobyov, Michael Dunham, Héctor G. Arce

Abstrakt

We couple non-magnetic, hydrodynamical simulations of collapsing protostellar cores with radiative transfer evolutionary models to generate synthetic observations. We then use these synthetic observations to investigate the extent to which a simple method for measuring protostellar disc masses used in the literature recovers the intrinsic masses of the discs formed in the simulations. We evaluate the effects of contamination from the surrounding core, partially resolving out the disc, optical depth, fixed assumed dust temperatures, inclination, and the dust opacity law. We show that the combination of these effects can lead to disc mass underestimates by up to factors of 2–3 at millimetre wavelengths and up to an order of magnitude or larger at submillimetre wavelengths. The optically thin portions of protostellar discs are generally cooler in the Class I stage than the Class 0 stage since Class I discs are typically larger and more optically thick, and thus more shielded. The observed disc mass distribution closely resembles the intrinsic distribution if this effect is taken into account, especially at millimetrewavelengths where optical depth effects are minimized. Approximately 50–70 per cent of protostellar discs observed to date with this method are consistent with the masses of the gravitationally unstable discs formed in the simulations, suggesting that at least some protostellar discs are likely sufficiently massive to fragment. We emphasize key future work needed to confirm these results, including assembling larger, less biased samples, and using molecular line observations to distinguish between rotationally supported, Keplerian discs and magnetically supported pseudodiscs.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Yale University

Journal

Monthly Notices of the Royal Astronomical Society

Band

444

Seiten

887-901

Anzahl der Seiten

15

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/stu1511

Publikationsdatum

2014

Peer-reviewed

Ja

ÖFOS 2012

103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucris.univie.ac.at/portal/de/publications/on-the-reliability-of-protostellar-disc-mass-measurements-and-the-existence-of-fragmenting-discs(e64bb378-c113-47a3-a148-b214f2452a4e).html