Disk formation during collapse of magnetized protostellar cores

By P. Hennebelle, Andrea Ciardi. 2009

179 citations recorded by the source corpus.

Context. In the context of star and planet formation, understanding the formation of disks is of fundamental importance. Aims. Previous studies found that the magnetic field has a very strong impact on the collapse of a prestellar cloud, by possibly suppressing the formation of a disk even for relatively modest values of the magnetic intensity. Since observations infer that cores have a substantial level of magnetization, this raises the question of how disks form. However, most studies have been restricted to the case in which the initial angle, α , between the magnetic field and the rotation axis equals 0°. Here we explore and analyse the influence of non aligned configurations on disk formation. Methods. We perform 3D ideal MHD, AMR numerical simulations for various values of μ , the ratio of the mass-to-flux to the critical mass-to-flux, and various values of α . Results. We find that disks form more easily as α increases from 0 to 90°. We propose that as the magnetized pseudo-disks become thicker with increasing α , the magnetic braking efficiency is lowered. We also find that even small values of α ($\simeq$10–20°) show significant differences with the aligned case. Conclusions. Within the framework of ideal MHD, and for our choice of initial conditions, centrifugally supported disks cannot form for values of μ smaller than $\simeq$3 when the magnetic field and the rotation axis are perpendicular, and smaller than about $\simeq$5–10 when they are perfectly aligned.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/a1027223ca8877388b0755706bc8d572309c8035

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Citations in the corpus

A Keplerian disk around a Class 0 source: ALMA observations of VLA1623A (2013, background): “…(Mellon & Li 2008); however, if the magnetic Appendices are available in electronic form at http://www.aanda.org field and rotation axes are misaligned, rotationally supported disks may form since the magnetic breaking efficiency is reduced (Hennebelle & Ciardi 2009; Krumholz et al. 2013).”
On the diversity and statistical properties of protostellar discs (2018, background): “If the magnetic field is misaligned with the rotation axis, this can reduce the braking (Hennebelle & Ciardi 2009; Joos et al. 2012; Li et al. 2014).”
H II REGIONS: WITNESSES TO MASSIVE STAR FORMATION (2010, background): “Banerjee & Pudritz (2006), Machida et al. (2005), Hennebelle & Teyssier (2008), Hennebelle & Fromang (2008) and Hennebelle & Ciardi (2009) furthermore show that the presence of magnetic fields can dramatically alter the shape and size of accretion disks and strongly suppress the formation of close…”
THE INTERPLAY OF MAGNETIC FIELDS, FRAGMENTATION, AND IONIZATION FEEDBACK IN HIGH-MASS STAR FORMATION (2010, methodology): “…dicular and parallel cases was computed by Mouschovias & Paleologou (1979, 1980), who found the criterion for braking to be effective is that outgoing helical Alfvén waves pass through a mass of external gas equal to that of the cloud (see also Basu & Mouschovias 1994; Hennebelle & Ciardi 2009).”
Protostellar disk formation and transport of angular momentum during magnetized core collapse (2012, methodology): “Following the previous studies of Hennebelle & Ciardi (2009) (see also Ciardi & Hennebelle 2010), we investigate in detail the transport of angular momentum, and the effects of magnetic braking in collapsing prestellar cores with aligned and misaligned configurations (α between 0◦ and 90◦).”
Collapse, outflows and fragmentation of massive, turbulent and magnetized prestellar barotropic cores (2011, background): “Indeed, Hennebelle & Ciardi (2009) show that when the magnetic field is misaligned with the rotation axis, the magnetic braking is less efficient.”
Effect of Magnetic Braking on Circumstellar Disk Formation in a Strongly Magnetized Cloud (2010, methodology): “This indicates that the magnetic field suppresses the disk formation, as already described in past studies (Mellon & Li 2008, 2009; Duffin & Pudritz 2009; Hennebelle & Ciardi 2009).”
NON-IDEAL MHD EFFECTS AND MAGNETIC BRAKING CATASTROPHE IN PROTOSTELLAR DISK FORMATION (2011, background): “When the magnetic and rotation axes are misaligned, Hennebelle & Ciardi (2009) found in their AMR MHD simulations that magnetic braking efficiency is reduced relative to the aligned case.”
The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Orion Protostars. II. A Statistical Characterization of Class 0 and Class I Protostellar Disks (2020, background): “Furthermore, nonidealized initial conditions that include turbulence or magnetic fields that are misaligned with respect to the rotation axis can also facilitate the formation of disks (e.g., Hennebelle & Ciardi 2009; Joos et al. 2012; Seifried et al. 2012).”
Small-scale dynamo action during the formation of the first stars and galaxies - I. The ideal MHD limit (2010, background): “…of magnetised molecular cloud cores in the context of present-day star formation (e.g. Hennebelle & Teyssier 2008; Hennebelle & Fromang 2008; Hennebelle & Ciardi 2009; Mellon & Li 2009) indicate that even modest field strengths can suppress binary formation and strongly favour the formation…”
The First Stars (2012, background): “Many early studies of the formation of primordial stars assumed that as the Jeans mass decreases and the gas becomes more gravitationally unstable, it begins to undergo hierarchical gravitational fragmentation in a manner similar to that envisaged by Hoyle (1953), with the result that at any given m”
TADPOL: A 1.3 mm SURVEY OF DUST POLARIZATION IN STAR-FORMING CORES AND REGIONS (2013, background): “…could have important consequences for the formation of circumstellar disks within rotating envelopes, since preferential misalignment of the B-field and the rotation axis should allow disks to form more easily (Hennebelle & Ciardi 2009; Krasnopolsky et al. 2012; Joos et al. 2012; Li et al. 2013).”
Physical Processes in the Interstellar Medium (2014, background): “…parent clouds (Nakamura & Li, 2007; Krumholz et al., 2007b), influence the properties of protostellar disks due to magnetic braking (Price & Bate, 2007a; Mellon & Li, 2009; Hennebelle & Ciardi, 2009; Seifried et al., 2011, 2012a,b, 2013), or slow down the overall evolution (Heitsch et al., 2001a).”