Previous | Session 81 | Next | Author Index | Block Schedule
Q. Zhu, J. H. Lacy, D.T. Jaffe (University of Texas)
We present our high resolution mid-infrared fine-structure line observations of an UCHII region - G29.96 -0.02. By stepping the telescope across the object, we mapped the region in [Ne II] 12.8{\mu} m, [Ar III] 8.99{\mu} m, [S III] 18.7{\mu} m, [S IV] 10.51{\mu} m, Hua 12.3{\mu} m with Texas Echelon Cross Echelle Spectrograph (TEXES) on the NASA IRTF 3m infrared telescope at Mauna Kea, Hawaii. Our 4km/s resolution observations enable us to measure the wavenumber of the [Ar III], [S III] and [S IV] lines accurately with an uncertainty less than 0.001 cm-1. Using the ionization code Cloudy, we fit the line fluxes and estimate the physical properties of the region and the ionizing source. The model shows that the emitting gas forms dense clumps with density ne~6*104cm-3. The filling factor of the emitting region is below 0.1. The ionized region is slightly over-abundant in neon, sulfur and argon. We also find that the spectral type (O7.5) predicted by Cloudy is two subtypes later than the value estimated from radio free-free continuum emission.
Acknowledgement: This work was supported by NSF grant AST-0205518.
The author(s) of this abstract have provided an email address for comments about the abstract: zhuqf@astro.as.utexas.edu
Previous | Session 81 | Next
Bulletin of the American Astronomical Society, 37 #4
© 2005. The American Astronomical Soceity.