Protostars and Planets VI, Heidelberg, July 15-20, 2013
RADIATION-MAGNETO-HYDRODYNAMICS MODELS FOR STAR FORMATION AND SYNTHETIC OBSERVATIONS
Commercon, Benoit (LERMA/LRA - UMR 8112 - Ecole Normale Sup´erieure, 24 rue Lhomond, 75231 Paris CEDEX 05, France)
Levrier, Francois (LERMA/LRA - UMR 8112 - Ecole Normale Sup´erieure, 24 rue Lhomond, 75231 Paris CEDEX 05, France)
Maury, Anaelle (Harvard Smithsonian Center for Astrophysics)
Henning, Thomas (Max Planck Institut fuer Astronomie, Konigsthul 17, 69117 Heidelberg, Germany)
Launhardt, Ralf (Max Planck Institut fuer Astronomie, Konigsthul 17, 69117 Heidelberg, Germany)
Dullemond, Cornellis (Zentrum fuer Astronomie der Universitat Heidelberg, Institut fuer Theoretische Astrophysik, Albert-Ueberle-Straße 2, 69120 Heidelberg, Germany)
Although predicted by theoretical models, the existence of first hydrostatic cores (FHSC) has yet to be convincingly demonstrated by (sub)millimeter observations, and the multiplicity at this early stage of the star formation process is poorly constrained.
We present a possible identification strategy for FHSC candidates and make predictions of ALMA dust continuum emission maps from these objects. This is done by post-processing three state-of-the-art radiation-magneto-hydrodynamic (RMHD) 3D adaptive mesh refinement calculations of first hydrostatic core models performed with the RAMSES code. We compute the dust thermal continuum emission with the 3D radiative transfer code RADMC-3D. We compute spectral energy distributions (SED) and usual evolutionary stage indicators such as bolometric luminosity and temperature, and then produce synthetic ALMA observations using the simulator included in the GILDAS software package.
We show that under certain conditions, FHSCs can be identified from dust continuum emission at 24 μm and 70 μm. We also show that single SEDs cannot help in distinguishing between the formation scenarios of the FHSC, i.e., between the magnetized and non-magnetized models. We identify which combinations of the different ALMA bands and array configurations represent our best chance of solving the fragmentation issue in these objects. We thus demonstrate how ALMA will help in identifying the physical processes occurring within collapsing dense cores: If the magnetic field is playing a role, the emission pattern will show evidence of a pseudo-disk and even of a magnetically driven outflow that hydrodynamical calculations cannot reproduce.
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