EPoS Contribution
EPoS Contribution
Shedding light on the initial conditions for the formation of disks and multiple systems: statistical results on Class 0 protostars properties from the CALYPSO Large program

Anaelle Maury
HSCfA/CEA Saclay AIM, Paris, FR
One of the main challenges to the formation of stars is the angular momentum problem: the gas contained in a typical star-forming core must reduce its specific angular momentum by 5 to 10 orders of magnitude to form a typical star such as our Sun, or else centrifugal forces will soon balance gravity and prevent inflow, accretion and the growth of the protostellar embryo. Early analytical analysis proposed that the formation of large (r > 100 AU) centrifugally supported disks or the fragmentation of the core into multiple systems would allow to transfer/split angular momentum and therefore solve the angular momentum problem. However, we still don't know how the progenitors of protoplanetary disks and multiple systems are formed during the youngest phases of protostellar formation. In fact, not much is known on the structure of protostellar envelopes surrounding the youngest protostars, on the small scales (50-300 AU) at which disks and multiple systems are routinely observed around more evolved YSOs, due to a lack of observations at a high angular resolution (1" resolution or better). Characterizing the multiplicity and disks properties in the youngest protostellar envelopes is crucial to solve the angular momentum problem, and ultimately constrain the formation and evolution models of solar-type stars. In order to tackle this issue, we obtained a large observing program with the Plateau de Bure interferometer (PdBI) and the IRAM 30m telescope. This large program, named CALYPSO (Continuum and Line in Young Protostellar Objects), consists in observing the molecular lines and millimeter continuum emission from an unprecedentedly large sample of 17 Class 0 protostars at very high spatial resolutions (0.3" i.e. 50-100 AU). I will present the results of CALYPSO regarding the multiplicity and disk properties of Class 0 protostars, and connect our results to existing datasets obtained with both the SMA and CARMA interferometers. Comparison of the observations with outcomes of numerical simulations for the formation of protostars (RAMSES code) will complete the picture of our present knowledge of the physics at work to form disks and multiple systems.
Caption: 1mm dust continuum emission maps of Class 0 protostars observed with CALYPSO. Disks and protostellar multiple systems are indicated as orange ellipses and green circles respectively. The nature of both elongated structures and secondary sources detected in the millimeter continuum emission can be assessed robustly thanks to multi-wavelength and molecular line emission analysis, which will be presented in the talk.
Collaborators:
P. Andre
A. Belloche
S. Maret
C. Codella
L. Testi
S. Cabrit
F. Gueth
S. Bontemps
B. Lefloch
A. Bacmann
S. Bottinelli
P. Hennebelle
R. Klessen
C. Dullemond
B. Commercon
Key publication

Suggested Sessions: Cores to Disks