Spitzer Space Telescope - General Observer Proposal #60060


A Wide-Field Survey for Low Mass Star Formation around the Galactic Massive
Young Cluster NGC 3603

Principal Investigator: Tom Megeath
           Institution: Ritter Observatory, University of Toledo

     Technical Contact: Tom Megeath, Ritter Observatory, University of Toledo

Co-Investigators: 
Dieter Nuernberger, European Southern Observatory                     
Hans Zinnecker, Astrophysical Institute Potsdam                       
Rupali Chandar, University of Toledo                                  

Science Category: star formation 
 Observing Modes: IRAC Post-Cryo Mapping
  Hours Approved: 3.8 

Abstract:
NGC 3603 is one of the most massive (~10,000 solar masses) and compact (5~pc)
young star clusters known in the Milky Way. It is therefore a candidate young
globular cluster, with properties similar to massive young clusters found in
other galaxies such as the LMC, M51 and the Antenna. Due to its proxmity and low
extinction, NGC 3603 is one of the few massive clusters where it is possible to
detect the low mass stars that dominate the total mass of the cluster. NGC 3603
lies in the center of a 40 pc diameter, 100,000 solar mass molecular cloud
complex; little is known about the stars forming in this complex. We propose the
first systematic survey of this complex using deep 3.6 and 4.5 micron Spitzer
imaging of a 59 by 57 pc region centered on NGC 3603. By combining this data
with scheduled VLT JHK imaging of the same field, we can detect and identify low
to intermediate mass stars with disks and protostars in the cloud complex. Our
goal is to probe the relationship between spatially extended OB associations and
compact clusters of OB stars. Our method is to compare the spatial distribution
of intermediate to low mass stars in the extended NGC 3603 complex to that found
in OB associations like Orion. Specifically, is NGC 3603 part of a large,
extended complex containing both clustered and distributed star formation, and
consequently similar to nearby associations? Or did NGC 3603 result from a
distinct, compact mode of star formation? These observations will give us unique
insight into the process of massive star cluster formation in other galaxies and
how this process may differ from star formation near the Sun.