MAGMA: The Magellanic MAGMA: The Magellanic Mopra Assessment Mopra Assessment Tony Wong Tony Wong University of Illinois at Urbana- Champaign Collaborators: Annie Hughes (Swinburne/ATNF), Erik Muller (Nagoya U.), Jorge Pineda (JPL), Juergen Ott (NRAO), Y. Fukui, A. Kawamura, Y. Mizuno (Nagoya U.), S. Maddison (Swinburne), J.-P. Bernard (CESR), Y. Chu, L. Looney (U. Illinois), C. Henkel (MPIfR), U. Klein (U. Bonn)
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MAGMA: The Magellanic Mopra Assessment Tony Wong University of Illinois at Urbana-Champaign Collaborators: Annie Hughes (Swinburne/ATNF), Erik Muller (Nagoya.
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MAGMA: The Magellanic MAGMA: The Magellanic Mopra AssessmentMopra Assessment
Tony WongTony WongUniversity of Illinois at Urbana-Champaign
Collaborators:Annie Hughes (Swinburne/ATNF), Erik Muller (Nagoya U.), Jorge Pineda (JPL), Juergen Ott (NRAO), Y. Fukui, A. Kawamura, Y. Mizuno (Nagoya U.), S. Maddison (Swinburne), J.-P. Bernard (CESR), Y. Chu, L. Looney (U. Illinois), C. Henkel (MPIfR), U. Klein (U. Bonn)
MotivationMagellanic Clouds
• Can obtain both a local (pc-scale) and global view of star formation and the ISM
• But, may not be in dynamical equilibrium
• Metallicity lower than Galaxy
Existing complete ISM surveys• CO (2.6’): NANTEN surveys (Fukui et al. 1999, 2008)
• HI (1’): ATCA + Parkes surveys (Stanimirovic et al. 1999, Kim et al. 2003)
• H: MCELS (Smith et al.)
• mid-IR: S3MC (Bolatto et al.), SAGE (Meixner et al.)
CO vs. HI in LMCNearest actively star-forming galaxy; can easily
achieve ~10 pc resolution with radio telescopes
NANTEN CO ATCA HI
Fukui et al. 2001, 2008 Kim et al. 2003
Why A New Survey?
~40 pc resolution of NANTEN CO survey leaves many molecular clouds unresolved.
SEST Key Program focused on clouds with bright H emission, and did not employ OTF.
MAGMA Components: LMC1. Molecular Ridge near 30 Doradus (MX002: 2005)• Properties of GMC’s as a function of radiation field
2. Survey of Clouds in the Inner LMC (M172: 2006-7)
• Properties of GMC’s across range of environments
• Large scale dynamics and the CO-HI relationship
3. Verifying Cloud Masses (M226; 2007)
• Compare virial and IR-based methods
4. A Complete Flux-Limited Sample (M300; 2008-9)
• Properties of the smallest bright CO clouds
MAGMA Targets
Molecular Ridge• 120 5’ x 5’ fields
• 3 sensitivity ~ 200 M per beam
NANTEN CO
Molecular Ridge
CO vs. HI in LMC
Mopra CO HI Peak Tb Eff. lwidthHI integral
CO - HI Offsets
At 1’ resolution, evidence for offsets between CO and HI peaks.
Posibly “warm atomic haloes” such as seen around Galactic GMCs (e.g. Andersson et al. 1991).
X Factor
Assuming clouds are virialized, there is little variation in the CO-to-H2
conversion factor as a function of ambient FUV field or distance from 30 Dor.
Cloud Mass Spectrum
Mass spectrum power law index of -1.8 resembles that observed in Galactic studies.