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Large Scale CO Emission in the Orion Nebula
Núria Marcelino (NRAO-CV)
Olivier Berné (Leiden Obs, The Netherlands)
José Cernicharo (CSIC/INTA, Spain)
HST CO (2-1)
Motivations The closest (brightest) massive star forming region Prototypical source: observed at almost all
wavelengths Star formation features: hot cores, HII regions,
protostars, circumstellar disks, outflows, HH objects,
PDRs, etc. 12CO and 13CO: spatial distribution, kinematics, and
column densities of molecular gas Previous large scale CO maps have poor spectral
and/or angular resolution
Postdoc Symposium, April 11 2011
Observations IRAM 30M radiotelescope (Granada, Spain)
Size 1ox0.8o (63 submaps), centered at IRc2/KL :
=05h35m14.5s, =-05o22’29.3’’
HERA 3x3 multibeam receiver
12CO (2-1) @ 230.5 GHz
13CO (2-1) @ 220.4 GHz
Angular resolution ~ 11’’
(0.02 pc @ 414 pc)
Velocity resolution ~ 0.4 km/s
Postdoc Symposium, April 11 2011
Postdoc Symposium, April 11 2011
12CO (2-1)
Postdoc Symposium, April 11 2011
13CO (2-1)
Postdoc Symposium, April 11 2011
12CO (2-1)
12CO emission @ -5 to 8 km/s
Postdoc Symposium, April 11 2011
Postdoc Symposium, April 11 2011
12CO emission @ -5 to 8 km/s
Postdoc Symposium, April 11 2011
IRAC 3.6 m
12CO emission @ -5 to 8 km/s
12CO emission @ -5 to 8 km/s
Postdoc Symposium, April 11 2011
Postdoc Symposium, April 11 2011
12CO emission @ -5 to 8 km/s
IRAC 3.6 m
Postdoc Symposium, April 11 2011
Orion Waves
Berné, Marcelino & Cernicharo (Nature, 466, 947)
Expansion of the HII region
provoked Kelvin-Helmholtz
instabilities and cloud
fragmentation
Intense and ionizing stellar irradiation
caused the acceleration of the clumps
First observational evidence of KH instabilities,
result of hydrodynamical feedback of massive stars
on their parental cloud
Postdoc Symposium, April 11 2011
12CO emission @ 8 to 12 km/s
Postdoc Symposium, April 11 2011
12CO emission @ 12 to 25 km/s
Postdoc Symposium, April 11 2011
Postdoc Symposium, April 11 2011
12CO emission @ 12 to 25 km/s
SCUBA 850 m
Conclusions Very complex dynamics and velocity structure
Clumps, filaments, cavities, pillars/cometary
globules, outflows, etc.
Interaction between massive star winds, HII
regions, and molecular ambient cloud: energy
transport, turbulence, formation of filaments,
triggered star formation, etc.
High angular and spectral resolutions are
essential to study in detail these processes
Postdoc Symposium, April 11 2011
12CO (2-1) emission
Postdoc Symposium, April 11 2011
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