166 citations · 1.5k across the 32 of their papers we have counts for
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Increasing mass-to-flux ratio from the dense core to the protostellar envelope around the Class 0 protostar HH 211
Hsi-Wei Yen, Patrick Koch, Chin-Fei Lee +7
To study transportation of magnetic flux from large to small scales in protostellar sources, we analyzed the Nobeyama 45-m N2H+ (1-0), JCMT 850 um polarization, and ALMA C18O (2-1)…
The role of magnetic fields in the formation of protostars, disks, and outflows
Yusuke Tsukamoto, Anaëlle Maury, Benoît Commerçon +6
We present our current understanding of the formation and early evolution of protostars, protoplanetary disks, and the driving of outflows as dictated by the interplay of magnetic…
Chemical and Physical Characterization of the Isolated Protostellar Source CB68: FAUST. IV
Muneaki Imai, Yoko Oya, Brian Svoboda +1
Chemical diversity of low-mass protostellar sources has so far been recognized, and environmental effects are invoked as its origin. In this context, observations of isolated proto…
The Central 1000 au of a Pre-stellar Core Revealed with ALMA. II. Almost Complete Freeze-out
Paola Caselli, Jaime E. Pineda, Olli Sipilä +18
Pre-stellar cores represent the initial conditions in the process of star and planet formation. Their low temperatures (10 K) allow the formation of thick icy dust mantles, whic…
The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability
Joaquin Zamponi, María José Maureira, Bo Zhao +4
Deeply embedded protostars are actively fed from their surrounding envelopes through their protostellar disk. The physical structure of such early disks might be different from tha…
FAUST II. Discovery of a Secondary Outflow in IRAS 15398-3359: Variability in Outflow Direction during the Earliest Stage of Star Formation?
Yuki Okoda, Yoko Oya, Logan Francis +66
We have observed the very low-mass Class 0 protostar IRAS 15398-3359 at scales ranging from 50 au to 1800 au, as part of the ALMA Large Program FAUST. We uncover a linear feature,…
The Interplay between Ambipolar Diffusion and Hall Effect on Magnetic Field Decoupling and Protostellar Disc Formation
Bo Zhao, Paola Caselli, Zhi-Yun Li +3
Non-ideal MHD effects have been shown recently as a robust mechanism of averting the magnetic braking "catastrophe" and promoting protostellar disc formation. However, the magnetic…
Hall Effect in Protostellar Disc Formation and Evolution
Bo Zhao, Paola Caselli, Zhi-Yun Li +3
The Hall effect is recently shown to be efficient in magnetized dense molecular cores, and could lead to a bimodal formation of rotationally supported discs (RSDs) in the first cor…
Formation and Evolution of Disks around Young Stellar Objects
Bo Zhao, Kengo Tomida, Patrick Hennebelle +9
Recent observations have suggested that circumstellar disks may commonly form around young stellar objects. Although the formation of circumstellar disks can be a natural result of…
Transition from ordered pinched to warped magnetic field on a 100 au scale in the Class 0 protostar B335
Hsi-Wei Yen, Bo Zhao, Patrick Koch +6
We present our observational results of the 0.87 mm polarized dust emission in the Class 0 protostar B335 obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) at a…
Impact of magneto-rotational instability on grain growth in protoplanetary disks: I. Relevant turbulence properties
Munan Gong, Alexei V. Ivlev, Bo Zhao +1
Turbulence in the protoplanetary disks induces collisions between dust grains, and thus facilitates grain growth. We investigate the two fundamental assumptions of the turbulence i…
Disk Formation in Magnetized Dense Cores with Turbulence and Ambipolar Diffusion
Ka Ho Lam, Zhi-Yun Li, Che-Yu Chen +2
Disks are essential to the formation of both stars and planets, but how they form in magnetized molecular cloud cores remains debated. This work focuses on how the disk formation i…
The central 1000 AU of a pre-stellar core revealed with ALMA. I. 1.3 mm continuum observations
Paola Caselli, Jaime E. Pineda, Bo Zhao +8
Stars like our Sun form in self-gravitating dense and cold structures within interstellar clouds, called pre-stellar cores. Although much is known about the physical structure of d…
JCMT POL-2 and ALMA polarimetric observations of 6000-100 au scales in the protostar B335: linking magnetic field and gas kinematics in observations and MHD simulations
Hsi-Wei Yen, Bo Zhao, I-Ta Hsieh +8
We present our analysis of the magnetic field structures from 6000 au to 100 au scales in the Class 0 protostar B335 inferred from our JCMT POL-2 observations and the ALMA archival…
Constraint on ion-neutral drift velocity in the Class 0 protostar B335 from ALMA observations
Hsi-Wei Yen, Bo Zhao, Patrick M. Koch +4
Ambipolar diffusion can cause a velocity drift between ions and neutrals. This is one of the non-ideal MHD effects proposed to enable the formation of Keplerian disks with sizes of…
Effect of Grain Size on Differential Desorption of Volatile Species and on Non-ideal MHD Diffusivity
Bo Zhao, Paola Caselli, Zhi-Yun Li
We developed a chemical network for modeling the chemistry and non-ideal MHD effects from the collapsing dense molecular clouds to protostellar disks. First, we re-formulated the c…
Molecular outflow launched beyond the disk edge
Felipe O. Alves, Josep M. Girart, Paola Caselli +5
One of the long-standing problems of star formation is the excess of angular momentum of the parent molecular cloud. In the classical picture, a fraction of angular momentum of the…
Decoupling of Magnetic Fields in Collapsing Protostellar Envelopes and Disk Formation and Fragmentation
Bo Zhao, Paola Caselli, Zhi-Yun Li +1
Efficient magnetic braking is a formidable obstacle to the formation of rotationally supported disks (RSDs) around protostars in magnetized dense cores. We have previously shown, t…
Protostellar Disk Formation Enabled by Removal of Small Dust Grains
Bo Zhao, Paola Caselli, Zhi-Yun Li +3
It has been shown that a realistic level of magnetization of dense molecular cloud cores can suppress the formation of a rotationally supported disk (RSD) through catastrophic magn…
On the Role of Pseudodisk Warping and Reconnection in Protostellar Disk Formation in Turbulent Magnetized Cores
Zhi-Yun Li, Ruben Krasnopolsky, Hsien Shang +1
The formation of rotationally supported protostellar disks is suppressed in ideal MHD in non-turbulent cores with aligned magnetic field and rotation axis. A promising way to resol…
Effect of Magnetic Misalignment on Protobinary Evolution
Bo Zhao, Zhi-Yun Li, Kaitlin M. Kratter
The majority of solar-type stars reside in multiple systems, especially binaries. They form in dense cores of molecular clouds that are observed to be significantly magnetized. Our…
Orbital and Mass Ratio Evolution of Protobinaries Driven by Magnetic Braking
Bo Zhao, Zhi-Yun Li
The majority of stars reside in multiple systems, especially binaries. The formation and early evolution of binaries is a longstanding problem in star formation that is not fully u…
Protostellar Accretion Flows Destabilized by Magnetic Flux Redistribution
Ruben Krasnopolsky, Zhi-Yun Li, Hsien Shang +1
Magnetic flux redistribution lies at the heart of the problem of star formation in dense cores of molecular clouds that are magnetized to a realistic level. If all of the magnetic…
Magnetic Flux Expulsion in Star Formation
Bo Zhao, Zhi-Yun Li, Fumitaka Nakamura +2
Stars form in dense cores of magnetized molecular clouds. If the magnetic flux threading the cores is dragged into the stars, the stellar field would be orders of magnitude stronge…