The first steps of planet formation : studying grain growth with millimetre interferometers

Lommen, D.J.P. (2009)

Doctoral Thesis

We present Submillimeter-Array (SMA) observations of two embedded young stellar objects, Elias 29 and IRS 63. The masses of the central stars, the discs, and the envelopes are determined for such young objects for the first time. A survey of bright T-Tauri stars in the southern constellations Lupus and Chamaeleon was carried out with the Australia Telescope Compact Array (ATCA) at 3 mm. The Lupus sources were subsequently observed with the SMA at 1 mm. Comparison with the 10-micron silicate features of seven of the sources suggested a correlation between the infrared and radio data. A large survey of T-Tauri stars was carried out with the SMA, the ATCA, the Combined Array for Research in Millimeter-wave Astronomy (CARMA), and the Very Large Array (VLA). The correlation between the infrared and radio data was confirmed, suggesting that planet formation in discs is more uniform then heretofore thought. Three bright T-Tauri stars were followed up with the ATCA at 7 mm, 1.6, 3.5, and 6.3 cm. Dust emission up to 7 mm was detected around CS Cha and RU Lup and even up to 1.6 cm for WW Cha, indicating that grains have grown up to sizes of at least several centimetres.

• Circumstellar matter
• Stars: formation
• Stars: planetary systems: protoplanetary discs
• Stars: pre-main-sequence
• Stars: individual: IRS 63
• Stars: individual: Elias 29
• Stars: individual: WW Cha
• Stars: individual: RU Lup
• Stars: individual: CS Cha

• All authors: Lommen, D.J.P.
• Supervisor: Dishoeck, E.F. van
• Co-supervisor: Langevelde, H.J. van; Wright, C.M.
• Qualification: Doctor (dr.)
• Awarding Institution: Faculty of Science, Leiden University
• Date: 2009-04-23