The 6.0 and 6.8μm absorption features in the spectrum of NGC 7538: IRS9.
Abstract
Short Wavelength Spectrometer observations of the 6.0 and 6.8μm absorption features towards the obscured young stellar object NGC 7538: IRS9 are presented and compared to the features of a number of species measured in the solid phase. It is found that while solid H_2_O provides the bulk of the 6μm band, additional absorption is required near 5.83μm and 6.25μm. It is proposed that formic acid (HCOOH) is a plausible candidate for the blue excess, while the red excess could be related to the C-C stretching mode in aromatic structures. Subsequently, a number of candidates for the 6.8μm band are reviewed. Unfortunately, none of these appears to satisfy the observational constraints and no plausible identification can at this point be presented.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 1996
- Bibcode:
- 1996A&A...315L.333S
- Keywords:
-
- ISM: DUST;
- EXTINCTION;
- ISM: MOLECULES;
- INFRARED: ISM: LINES AND BANDS;
- STARS: PRE-MAIN-SEQUENCE;
- STARS: INDIVIDUAL: NGC 7538 IRS9