EPoS Contribution
EPoS Contribution
First results from the CALYPSO IRAM-PdBI survey: a high-angular-resolution study of the NGC1333-IRAS2A Class 0 protostar

Sebastien Maret
IPAG, Grenoble, FR
Despite some progress in the past two decades, the physics of the youngest protostars (Class 0 objects) remains poorly understood. Recent observations have revealed the presence of Keplerian disks in a couple of Class 0 protostars, but it is not clear if such disks are common. Likewise, the launching mechanism of protostellar jets and their net contribution to mass and angular momentum extraction during protostar formation is strongly debated. The complex velocity and density structure shaping the inner protostellar environment is also a great puzzle to star formation models. Finally, the origin of complex organic molecules (COMs) emission observed in some of these protostars is still not completely understood. To solve these issues, we have started a large program with the IRAM Plateau de Bure and 30m telescopes. This program, named CALYPSO (Continuum and Lines in Young Protostellar Objects, consists in observing the line and continuum emissions from a large (17) sample of nearby Class 0 protostars at sub-arcsecond resolution. In this contribution, we will present the first results of the CALYPSO survey on the NGC1333-IRAS2A protostar. For the first time, we disentangle this source into a proto-binary system, revealing two protostars (MM1, MM2) separated by ~560 AU, each of them driving their own jet. MM1 is associated with compact, yet resolved, methanol and other COMs emissions. The size and the morphology of the emissions suggest that they originate in a hot corino. Finally, the methanol emission reveals a marginal velocity gradient perpendicular to the direction of outflow. However, this gradient appears inconsistent with a Keplerian disk. Instead, we suggest that the methanol emission originates from the infalling and perhaps slowly rotating envelope, around a central protostar of 0.1- 0.2 solar masses. Preliminary results on other sources of the survey will also be discussed.
Caption: Continuum and line emissions observed towards NGC1333-IRAS2A with the Plateau de Bure interferometer. The upper left panel shows the 1mm continuum emission. The main continuum sources, MM1, MM2 and MM3, are indicated. The other panels show the line emission (blue, red and green contours) together with the continuum (grey-scale image). The systemic velocity of the source is 6.5 km/s. For the SO and SiO maps, the blue and red contours correspond to velocities < 3 km/s and > 11 km/s, respectively. For the CH3OH lines, they correspond to velocities < 6.5 km/s and > 6.5 km/s, respectively. The CH3OCHO line is spectrally unresolved, and the green contours correspond to velocities between 4 km/s and 9 km/s. In each panel the dashed ellipse indicates the size and orientation of the synthesized beam. The dashed line shows the orientation of the outflow driven by MM1. From Maret et al. (2014), Maury et al. (2014) and Codella et al. (2014).
Collaborators:
A. J. Maury, CEA, France
C. Codella, Arcetri Obs., Italy
P. Andre, CEA, France
A. Belloche, MPIfR, Germany
F. Gueth, IRAM, France
S. Cabrit, LERMA/IPAG, France
S. Bontemps, LAB, France
L. Testi, ESO, Germany
Key publication

Suggested Sessions: Cores to Disks