A mid-infrared study of HII regions in the Magellanic Clouds: N88A and N160A

Abstract

To show the importance of high-spatial resolution observations of HII regions when compared with observations obtained with larger apertures such as ISO, we present mid-infrared spectra of two Magellanic Cloud HII regions, N88A and N160A. We obtained mid-infrared (8-13 um), long-slit spectra with TIMMI2 on the ESO 3.6m telescope. These are combined with archival spectra obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, and are compared with the low-spatial resolution ISO-SWS data. An inventory of the spectra in terms of atomic fine-structure lines and molecular bands is presented. Concerning N88A, an isolated HII region with no adjacent infrared sources, the observations indicate that the line fluxes observed by ISO-SWS and Spitzer-IRS come exclusively from the compact HII region of about 3 arcsec in diameter. This is not the case for N160A, which has a more complex morphology. We have spectroscopically isolated for the first time the individual contributions of the three components of N160A, two high-excitation blobs, A1 and A2, and the young stellar object N160A-IR. In addition, extended [SIV] emission is observed with TIMMI2 and is most likely associated with the central star cluster located between A1 and A2. We show the value of these high-spatial resolution data in determining source characteristics, such as the degree of ionization of each high-excitation blob or the bolometric luminosity of the YSO. This luminosity is about one order of magnitude lower than previously estimated. For each high-excitation blob, we also determine the electron density and the elemental abundances of Ne, S, and Ar.

arXiv comment13 pages, 8 figures, accepted for publication in A&A

References in corpus (15)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The Spitzer Space Telescope Mission
• Dust Grain Size Distributions and Extinction in the Milky Way, LMC, and SMC
• The Infrared Spectrograph on the Spitzer Space Telescope
• A Quantitative Comparison of SMC, LMC, and Milky Way UV to NIR Extinction Curves
• A new calibration of stellar parameters of Galactic O stars
• The rich 6 to 9 um spectrum of interstellar PAHs
• The CH out-of-plane bending modes of PAH molecules in astrophysical environments
• User Manual for DUSTY
• The effect of metallicity on the Cepheid Period-Luminosity relation from a Baade-Wesselink analysis of Cepheids in the Galaxy and in the Small Magellanic Cloud
• The Embedded Super Star Cluster of SBS0335-052
• Mid-IR observations of Galactic HII regions: constraining ionizing spectra of massive stars and the nature of the observed excitation sequences
• Massive Young Stellar Objects in the Large Magellanic Cloud: water masers and ESO-VLT 3-4 micron spectroscopy
• Metallicity and the spectral energy distribution and spectral types of dwarf O-stars
• Resolving the compact HII regions in N160A with HST

Cited by in corpus (3)

• $K$-band integral field spectroscopy and optical spectroscopy of massive young stellar objects in the Small Magellanic Cloud
• VLT/NACO near-infrared imaging and spectroscopy of N88A in the SMC
• Near-Infrared Polarimetric Study of N159/N160 Star-Forming Complex in the Large Magellanic Cloud