Searching for kinematic evidence of Keplerian disks around Class 0 protostars with CALYPSO

S Maret,S Anderl,Ph André,P Hennebelle,L Podio,A Belloche,S Cabrit,A J Maury,C Codella,F Gueth,M Gaudel,C Lefévre

doi:10.1051/0004-6361/201936798

Abstract

The formation of protoplanetary disks is not well understood. To understand how and when these disks are formed, it is crucial to characterize the kinematics of the youngest protostars at a high angular resolution. Here we study a sample of 16 Class 0 protostars to measure their rotation profile at scales from 50 to 500 au and search for Keplerian rotation. We used high-angular-resolution line observations obtained with the Plateau de Bure Interferometer as part of the CALYPSO large program. From 13CO (J = 2−1), C18O (J = 2−1) and SO (Nj = 56−45) moment maps, we find that seven sources show rotation about the jet axis at a few hundred au scales: SerpS-MM18, L1448-C, L1448-NB, L1527, NGC 1333-IRAS 2A, NGC 1333-IRAS 4B, and SVS13-B. We analyzed the kinematics of these sources in the uv plane to derive the rotation profiles down to 50 au scales. We find evidence for Keplerian rotation in only two sources, L1527 and L1448-C. Overall, this suggests that Keplerian disks larger than 50 au are uncommon around Class 0 protostars. However, in some of the sources, the line emission could be optically thick and dominated by the envelope emission. Due to the optical thickness of these envelopes, some of the disks could have remained undetected in our observations.

Highlights

Protoplanetary disks are the birth site of planetary systems
From 13CO (J = 2−1), C18O (J = 2−1) and SO (N j = 56−45) moment maps, we find that seven sources show rotation about the jet axis at a few hundred au scales: SerpS-MM18, L1448-C, L1448-NB, L1527, NGC 1333-IRAS 2A, NGC 1333-IRAS 4B, and SVS13-B
We present high-angular millimeter line interferometric observations of a sample of 16 Class 0 protostars obtained with the Institut de Radioastronomie Millimétrique (IRAM) Plateau de Bure interferometer as part of the CALYPSO (Continuum and Line from Young Protostellar Objects) survey

Summary

Introduction

Protoplanetary disks are the birth site of planetary systems. Determining how and when these disks are formed is, important for understanding the formation of planetary systems. Protoplanetary disks are ubiquitous around Class II young stellar objects. Disks around the youngest Class 0 protostars are more difficult to observe. Because these objects are the youngest accreting protostars, most of their mass is still in the form of an envelope (André et al 1993, 2000; Dunham et al 2014), which makes the detection of a disk challenging. The observation and the characterization of disks around young embedded protostars are key to understanding the formation of disks

Results

Discussion

Conclusion