Turbulence and its connection to episodic accretion in binary YSOs

• Verfasst von: Riaz, Rafeel [VerfasserIn]
• Verfasst von: Schleicher, Dominik R. G. [VerfasserIn]
• Verfasst von: Vanaverbeke, S. [VerfasserIn]
• Verfasst von: Klessen, Ralf S. [VerfasserIn]
• Titel: Turbulence and its connection to episodic accretion in binary YSOs
• Verf.angabe: R. Riaz, D.R.G. Schleicher, S. Vanaverbeke and Ralf S. Klessen
• E-Jahr: 2021
• Jahr: 02 September 2021
• Umfang: 17 S.
• Fussnoten: Gesehen am 17.11.2021
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2021
• Band/Heft Quelle: 507(2021), 4, Seite 6061-6077
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stab2489
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1777654254

Abstract

We report signatures of episodic accretion in young stellar objects (YSOs) that emerge in protobinary configurations in a gravoturbulent gas collapse. We find in most of these protobinary systems strong accretion bursts between the two companions with a recurrence time-scale of about 1 kyr. The accretion rate on to the secondary star typically exceeds that on to the primary with a peak value of 2 × 10−2 M⊙ yr−1 for the former and 6 × 10−3 M⊙ yr−1 for the latter. We propose that the secondary companion, which remains more active in its episodes of accretion bursts, especially for the gas cores with subsonic velocity dispersion, may provide observational opportunities to find traces of episodic accretion in the surrounding gas of the embedded YSOs that are in a binary configuration. Also, protostars evolving as single objects in the same environment show fewer accretion bursts and all together a more steady mass growth history. The prestellar cores with subsonic velocity dispersion exhibit an order of magnitude more intense accretion bursts than in the case of cores with supersonic velocity dispersions. The latter shows the formation of some of the protobinaries in which the primary acts as a more actively accreting companion. This can support these binaries to become systems of extreme mass ratio. Moreover, the YSOs in binary configurations with small semimajor axis a ≈ 50 au and high mass ratio q > 0.7 support phases of intense episodic accretion. The eccentricity, however, seems to play no significant role in the occurrence of accretion bursts.