We wish to constrain the possible contribution of a magnetohydrodynamic disk wind (DW) to the HH212 molecular jet. We mapped the flow base with ALMA Cycle 4 at 0 . 13 ∼ 60 au resolution and compared these observations with synthetic DW predictions. We identified, in SO/SO 2 , a rotating flow that is wider and slower than the axial SiO jet. The broad outflow cavity seen in C 34 S is not carved by a fast wide-angle wind but by this slower agent. Rotation signatures may be fitted by a DW of a moderate lever arm launched out to ∼40 au with SiO tracing dust-free streamlines from 0.05−0.3 au. Such a DW could limit the core-to-star efficiency to ≤50%.
We present polarimetric data of CW Tau and DG Tau, two well-known Class II disk/jet systems, obtained with the Atacama Large Millimeter/submillimeter Array at 870 µm and 0. ′′ 2 average resolution. In CW Tau, the total and polarized emission are both smooth and symmetric, with polarization angles almost parallel to the minor axis of the projected disk. In contrast, DG Tau displays a structured polarized emission, with an elongated brighter region in the disk's near side and a belt-like feature beyond about 0. ′′ 3 from the source. At the same time the total intensity is spatially smooth, with no features. The polarization pattern, almost parallel to the minor axis in the inner region, becomes azimuthal in the outer belt, possibly because of a drop in optical depth. The polarization fraction has average values of 1.2% in CW Tau and 0.4% in DG Tau. Our results are consistent with polarization from self-scattering of the dust thermal emission. Under this hypothesis, the maximum size of the grains contributing to polarization is in the range 100 -150 µm for CW Tau and 50 -70 µm for DG Tau. The polarization maps combined with dust opacity estimates indicate that these grains are distributed in a geometrically thin layer in CW Tau, representing a settling in the disk midplane. Meanwhile, such settling is not yet apparent for DG Tau. These results advocate polarization studies as a fundamental complement to total emission observations, in investigations of the structure and the evolution of protoplanetary disks.
Complex organic molecules have been observed for decades in the interstellar medium. Some of them might be considered as small bricks of the macromolecules at the base of terrestrial life. It is hence particularly important to understand organic chemistry in Solar-like star-forming regions. In this article, we present a new observational project: Seeds Of Life In Space (SOLIS). This is a Large Project using the IRAM-NOEMA interferometer, and its scope is to image the emission of several crucial organic molecules in a sample of Solar-like star-forming regions in different evolutionary stages and environments. Here we report the first SOLIS results, obtained from analyzing the spectra of different regions of the Class 0 source NGC 1333-IRAS4A, the protocluster OMC-2 FIR4, and the shock site L1157-B1. The different regions were identified based on the images of formamide (NH 2 CHO) and cyanodiacetylene (HC 5 N) lines. We discuss the observed large diversity in the molecular and organic content, both on large (3000-10,000 au) and relatively small (300-1000 au) scales. Finally, we derive upper limits to the methoxy fractional abundance in the three observed regions of the same order of magnitude of that measured in a few cold prestellar objects, namely 10 12 --10 −11 with respect to H 2 molecules.
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