Thermal infrared imaging of the bipolar H II region S106

Nathan Smith, Terry J. Jones, Robert D. Gehrz, Dimitri Klebe, Michelle J. Creech-Eakman

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


The extended infrared emission from Sharpless 106 shows complex structure in ground-based images obtained at wavelengths from 3 to 20 μm. The structure of the ionization fronts and photodissociation regions are resolved in Brα emission at 4.05 μm and emission from polycyclic aromatic hydrocarbons at 3.29 μm, with the H I emission residing interior to the hydrocarbon emission. The mid-infrared observations at 10 to 20 μm reveal the distribution of continuum emission from warm dust in the nebula. These images have a higher spatial resolution than previous mid-infrared maps, but they support earlier findings of a relatively constant dust color temperature of ∼ 135 K in the extended dust, excluding the dust near the self-luminous sources IRS 2 and 4. All infrared images presented here show a dark lane bisecting the nebula, which probably results from shadowing of light from the central engine rather than line-of-sight extinction. If this shadow is caused by a compact disk around IRS 4, its ionized inner edge would be within the radio photosphere of the stellar wind at wavelengths longer than about 1.5 cm. There appears to be a faint point source seen at near-infrared wavelengths that is coincident with the position of a bright far-infrared source. This source is adjacent to some bright near-infrared nebulosity but is not clearly detected in thermal infrared dust emission.

Original languageEnglish (US)
Pages (from-to)984-991
Number of pages8
JournalAstronomical Journal
Issue number2
StatePublished - Feb 2001


  • H II regions
  • ISM: individual (S106)
  • Stars: formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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