SiO Maser+7mm Continuum
Image of Orion Source I
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KALYPSO Project Description
High-mass stars are important components in the ecology of the interstellar medium (ISM)
and the evolution of galaxies. They profoundly change the chemical and physical composition, and the energy budget, of the ISM. When young they disrupt parent molecular clouds, driving
powerful outflows and emitting enormous UV fluxes that ionize HII regions.
When old they explode as supernova and enrich the ISM with heavy elements, thereby
influencing chemical and thermodynamic processes, and planting seed material from
which planets can ultimately form.
However, there is at present no general theory of high-mass star formation. The balance of forces (e.g., magnetic) that affect material around massive young stellar objects
(YSOs) and protostars has been difficult to infer reliably from observations
(due largely to large distances, high extinction, clustering, and crowding).
The goal of the KaLYPSO project is to directly map and track the 3-D dynamics of
gas around a massive, deeply embedded YSO in Orion-KL, at radii of 10 to 1000 AU,
where outflow is launched from the accretion disk. This has never before been done.
It is currently possible for just one known YSO, the target of our study, and
lessons learned in this case will inform interpretation of data for most other massive YSOs.
We will concentrate on three key questions: (i) what is the accretion disk structure 10 AU from a massive YSO; (ii) what is the outflow structure 10-1000 AU from a massive YSO; and (iii) what mechanisms shape and drive the disks and outflows - specifically, are magnetic fields important?
Kalypso Group Publications
- A Feature Movie of SiO Emission 20-100 AU from
the Massive Young Stellar Object Orion Source I,, Matthews et al. 2010, ApJ, 708, 80;
Accompanying animated movies: Figure 5b (total intensity),
Figure 7c (first moment)
- Maser Emission from SiO Isotopologues
Traces the Innermost 100 AU around Radio Source I in Orion BN/KL, Goddi et al. 2009, ApJ, 698, 1165
- A 42.3-43.6 GHz
spectral survey of Orion BN/KL: First detection of the v=0 J=1-0 line
from the isotopologues 29SiO and 30SiO, Goddi et al. 2009, ApJ, 691, 1254
- Disks, Young Stars, and
Radio Waves: the Quest for Forming Planetary Systems,
C. J. Chandler and D. S. Shepherd, 2008, in the
proceedings of the NRAO 50th Anniversary Science Symposium "Frontiers
of Astrophysics", ASP Conf. Series, 395, p. 193
- A Documentary of
High-Mass Star Formation: Probing the Dynamical Evolution of Orion
Source I on 10-100~AU Scales using SiO Masers, Matthews et
al. 2008, in the proceedings of IAU Symposium 242, ''Astrophysical Masers and Their Environments", ed. J. M. Chapman and
W. A. Baan, p. 130
- High Angular Resolution Mid-infrared Imaging of Young Stars in Orion BN/KL, Greenhill et al. 2004, Ap.J. 605 L57-L60
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