Cores to Disks

Cores to Disks
Name	Cores to Disks
Caption	Conceptual progression from dense cores to protostellar disks
Field	Astrophysics, Astronomy, Planetary Science
Related	Star formation; Protoplanetary disks; Molecular clouds

Cores to Disks Cores to Disks is a paradigm in astrophysics and astronomy describing the transformation of dense molecular cloud cores into rotationally supported protostellar and protoplanetary disks. It connects observations from facilities such as the Atacama Large Millimeter/submillimeter Array (ALMA), the Spitzer Space Telescope, and the Herschel Space Observatory to theoretical work by research groups at institutions like the Harvard–Smithsonian Center for Astrophysics, the Max Planck Institute for Astronomy, and the National Radio Astronomy Observatory. The framework informs understanding of subsequent planet formation studied by teams at the European Southern Observatory, the Jet Propulsion Laboratory, and the Space Telescope Science Institute.

Introduction

The Cores to Disks narrative synthesizes studies of dense cores in regions such as the Orion Nebula, Perseus Molecular Cloud, and Taurus Molecular Cloud with disk surveys of sources like HL Tauri, TW Hydrae, and Beta Pictoris. It links observational programs led by the Sloan Digital Sky Survey, the Hubble Space Telescope Key Projects, and the Keck Observatory to numerical efforts from groups at Princeton University, the University of Cambridge, and the California Institute of Technology. The program frames questions central to the legacies of the Voyager program, the New Horizons mission, and the Cassini–Huygens investigations.

Background and Motivation

Motivation arises from early mapping of molecular clouds with instruments like the James Clerk Maxwell Telescope and from theoretical ideas dating to work by Lyman Spitzer, Fred Hoyle, and Edwin Salpeter. The detection of prestellar cores via surveys by the IRAS mission and follow-up with JCMT and IRAM propelled collaborations involving the European Space Agency and the National Aeronautics and Space Administration. Key drivers include linking core mass functions reported by teams at the Max Planck Society to disk mass distributions characterized by researchers at Carnegie Institution for Science and understanding angular momentum transport studied in the context of the Magnetorotational instability literature influenced by Subrahmanyan Chandrasekhar and Steven Balbus.

Observational Techniques

Surveys use continuum and molecular line observations with ALMA, Very Large Array (VLA), and the Submillimeter Array to probe density and kinematics in regions surveyed by the Two Micron All Sky Survey and the Wide-field Infrared Survey Explorer. Infrared spectra from Spitzer, imaging from Hubble Space Telescope instruments like the Wide Field Camera 3, and polarimetry from facilities such as the Stratospheric Observatory for Infrared Astronomy (SOFIA) complement millimeter observations. Techniques draw on methods developed for the Sloan Digital Sky Survey and analysis pipelines from the European Southern Observatory and the National Optical-Infrared Astronomy Research Laboratory.

Formation and Evolution Processes

The conversion of dense cores identified in maps of the Perseus Molecular Cloud and Serpens South into disks around protostars analogous to IRAS 16293-2422 involves collapse regulated by magnetic fields studied in the context of André Maeder's work and outflows traced to objects like HH 212 and HH 30. Processes include rotational flattening, disk accretion explored by teams following Shu Shu-Fan-style collapse models, and fragmentation linked to results from groups at MIT and University of California, Berkeley. Feedback from young stellar objects compared to phenomena in Orion KL and effects analogous to jets observed in T Tauri stars are central.

Theoretical Models and Simulations

Numerical efforts employ magnetohydrodynamic codes developed at Princeton University, University of Chicago, and the Max Planck Institute for Astrophysics to simulate collapse from core scales to disk scales, building on analytic foundations by Ebert Bonnor and work inspired by Henrik Svensson and Mihalas. Models incorporate radiative transfer frameworks used by teams at the Institute for Advanced Study and microphysics parametrizations from groups at Stanford University and ETH Zurich. Large-scale simulation campaigns run on supercomputers at Oak Ridge National Laboratory and Lawrence Livermore National Laboratory enable comparison with ALMA and James Webb Space Telescope predictions.

Key Results and Empirical Findings

Empirical studies report relationships between core mass functions in clouds like Taurus and disk mass distributions for systems such as HL Tauri and AS 209, showing trends analyzed by consortia at the National Astronomical Observatory of Japan and the Australian National University. Observations reveal early disk formation in Class 0 sources similar to VLA 1623 and angular momentum profiles consistent with magnetically regulated collapse reported by researchers at Caltech and University of Toronto. Surveys by the Gould Belt Survey and programs at the Subaru Telescope find multiplicity statistics linking prestellar fragmentation to binary systems studied in the Gaia catalog.

Implications for Planet Formation

Results inform planet formation scenarios tested against exoplanet demographics from missions like Kepler and TESS, and population syntheses developed at University of Michigan and University College London. Disk mass and chemistry measured toward systems such as TW Hydrae and HD 163296 constrain core accretion and pebble accretion theories advanced by groups at University of Copenhagen and University of Zurich. Connections are drawn to Solar System formation constraints from studies of meteorites and the isotopic work associated with researchers at Caltech and the Field Museum.

Future Directions and Open Questions

Future work will leverage synergy among ALMA, JWST, the Square Kilometre Array, and next-generation facilities at Thirty Meter Telescope and the European Extremely Large Telescope to resolve disk substructure in younger protostars. Open questions include the role of magnetic braking debated by teams at University of Oxford and Yale University, the universality of the core mass function discussed by researchers at IAP, Paris and the Max Planck Institute for Radio Astronomy, and links to exoplanet architectures cataloged by European Space Agency missions. Cross-disciplinary efforts with groups at NASA Ames Research Center and the Smithsonian Astrophysical Observatory will be central to advancing the Cores to Disks agenda.

Category:Star formation