Extremely low temperatures and relatively low densities characterize the interstellar clouds precursors of stars and planets. In these early stages, fundamental chemical and physical processes affect each other, ultimately regulating clouds' dynamical evolution toward the formation of stellar systems like ours, where at least one habitable planet is present. Here, I'll present a journey from...
A plethora of new enigmatic phenomena in the innermost parts of protostellar systems associated with jets and outflows have been revealed by ALMA and JWST. These jets and outflows, along with the streamers from their magnetically collapsing prenatal envelopes, are integral parts of the physical processes that assemble the systems. We review the characteristics of these enigmatic, powerful...
Characterizing the molecular emission from whole molecular clouds is critical to identify the physical and chemical processes that act at different spatial scales and lead to the formation of stars. It is also needed to connect spatially-resolved observations of galactic clouds with extragalactic observations that do not resolve the clouds.
The traditional approach of characterizing the...
Located at the edge of the Cepheus Bubble, the massive star-forming region Cepheus A hosts HW2, a very young star growing more than dozen times the mass of our Sun - and the second closest of its kind to us. Using sensitive VLA observations, we have finally imaged its debated accretion disk in hot ammonia at centimeter wavelengths. We have resolved the accretion disk within a few hundred au of...
Sun-like stars are thought to accrete most of their final mass during the protostellar phase, where the protostellar embryo is surrounded by an infalling dense envelope. The so-called Class 0 phase designates the youngest protostellar stage, where the accretion is the most vigorous. Because these objects are highly embedded, it is difficult to retrieve direct diagnostics from the accretion,...
Stars form preferentially in clusters deeply embedded inside massive molecular clouds. Some of these clusters contain high-mass stars that influence their immediate environment through gravitational, mechanical and radiative interactions, and eventually through supernova explosions. Therefore, a comprehensive understanding of star formation requires characterizing the formation and early...
For many years, evidence of large-scale velocity gradients has been found in molecular clouds and filaments, which are commonly associated with rotation. It is known that during the collapse and fragmentation of these structures, a process of redistribution and loss of angular momentum is involved, such that the fragments possess less angular momentum per unit of mass than their parent...
Pierre Dumond, Adnan Ali Ahmad, Valentin Vallucci-Goy, Ashley Bemis, Ilseung Han
We present high-resolution (0.05"; 8 au) dust continuum and molecular line observations toward the Class I protostellar system IRAS 04169+2702 in the Taurus B213 region ($d$ = 156 pc), as part of the ALMA Large Program Early Planet Formation in Embedded Disks (eDisk). The 1.3-mm dust continuum emission traces a circumstellar disk with a central depression toward the protostar. Our...
The characterisation of cosmic dust properties is key for understanding, among other things, star and planet formation processes. Astronomical observations provide us information from which it is possible, but not trivial, to deduce physical properties of cosmic dust. For instance, recent observations of 12 young protostars found dust emissivity indices with values β < 1 [Maury et al. 2019,...
Theoretical models suggest that jet-driven bow shocks govern Class 0/I molecular outflow morphologies extending up to $10^{4-5}$ au, with additional modifications arising from binary motion, precession, and ambient interactions due to other outflows produced by clustered or binary protostars. Previous studies have demonstrated that outflow interactions in clustered environments are common,...
Regions with higher star formation rates are thought to have more dense, molecular gas that serves as the direct fuel for star formation. However, resolved studies of nearby galaxies find systematic variations in the star formation efficiency of dense gas (SFEdense) with local galactic environment. One physical explanation for this behaviour is the suppression of star formation in dense...
The giant molecular cloud Sagittarius B2 (hereafter SgrB2) is the most massive region with ongoing high-mass star formation in the Galaxy. In the southern half of the 20-pc large envelope of SgrB2, we encounter the SgrB2(DS) region which hosts more than 60 high-mass proto-stellar cores distributed in an arc shape around an extended HII region. We use the Very Large Array in its CnB and D...
