Resolved 24.5 micron emission from massive young stellar objects
arXiv:0811.4050 · doi:10.1051/0004-6361:200810771
Abstract
Massive young stellar objects (MYSO) are surrounded by massive dusty envelopes. Our aim is to establish their density structure on scales of ~1000 AU, i.e. a factor 10 increase in angular resolution compared to similar studies performed in the (sub)mm. We have obtained diffraction-limited (0.6") 24.5 micron images of 14 well-known massive star formation regions with Subaru/COMICS. The images reveal the presence of discrete MYSO sources which are resolved on arcsecond scales. For many sources, radiative transfer models are capable of satisfactorily reproducing the observations. They are described by density powerlaw distributions (n(r) ~ r^(-p)) with p = 1.0 +/-0.25. Such distributions are shallower than those found on larger scales probed with single-dish (sub)mm studies. Other sources have density laws that are shallower/steeper than p = 1.0 and there is evidence that these MYSOs are viewed near edge-on or near face-on, respectively. The images also reveal a diffuse component tracing somewhat larger scale structures, particularly visible in the regions S140, AFGL 2136, IRAS 20126+4104, Mon R2, and Cep A. We thus find a flattening of the MYSO envelope density law going from ~10 000 AU down to scales of ~1000 AU. We propose that this may be evidence of rotational support of the envelope (abridged).
21 pages, accepted for A&A
References in corpus (14)
- The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
- An Ultraviolet-to-Radio Broadband Spectral Atlas of Nearby Galaxies
- A SCUBA imaging survey of ultracompact HII regions: The environments of massive star formation
- The RMS Survey: Mid-Infrared Observations of Candidate Massive YSOs in the Southern Hemisphere
- Constraining the Envelope Structure of L1527 IRS: Infrared Scattered Light Modeling
- A Photoevaporating Rotating Disk in the Cepheus A HW2 Star Cluster
- Millimeter interferometry of W3 IRS5: A Trapezium in the making
- An equatorial wind from the massive young stellar object S140 IRS 1
- A high-frequency radio continuum study of massive young stellar objects
- Mid-Infrared Source Multiplicity within Hot Molecular Cores traced by Methanol Masers
- VLTI/MIDI 10 micron interferometry of the forming massive star W33A
- A red supergiant nebula at 25 micron: arcsecond scale mass-loss asymmetries of mu Cep
- The Complex Mid-Infrared Structure at the Heart of IRAS 20126+4104
- Disks around massive young stellar objects: are they common?