Extended red emission and unidentified infrared bands in the galactic compact H II region Sh 152

S. Darbon (1) , Annie Zavagno (2) , J. -M. Perrin , C. Savine , V. Ducci , J. -P. Sivan (2)

1 DAM/DIF - DAM Île-de-France
2 LAM - Laboratoire d'Astrophysique de Marseille

We present visible and infrared images and low-dispersion visible spectra of the galactic compact H Ii region Sh 152. The spatial distribution of the Extended Red Emission (ERE) over the nebula is found to coincide with that of the ionized hydrogen emission and to differ from that of the Unidentified InfraRed Bands (UIRBs) emission at 3.3 and 6.2 mu m. This result and other considerations are in favour of grains as carriers of the ERE. It is shown that nanosized silicon particles could account for the ERE in terms of luminescence, an interpretation which, however, suffers from some limitations.

Keywords: SCATTERING; ISM: INDIVIDUAL OBJECTS: SH 138; ISM: DUST; EXTINCTION; ISM: H II REGIONS; INFRARED: ISM: LINES AND BANDS

Domains: Sciences of the Universe [physics]

S. Darbon, Annie Zavagno, J. -M. Perrin, C. Savine, V. Ducci, et al.. Extended red emission and unidentified infrared bands in the galactic compact H II region Sh 152. Astronomy and Astrophysics - A&A, 2000, 364, pp.723-731. ⟨hal-03562783⟩