Title of article :
Testing the "strong" PAHs hypothesis - II. A quantitative link between DIBs and far-IR emission features
Author/Authors :
Malloci، G. نويسنده , , Mulas، G. نويسنده , , Benvenuti، P. نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2003
Abstract :
In Paper I (Malloci et al. 2003) we proved the profile invariance of the first permitted electronic transition of the typical Polycyclic Aromatic Hydrocarbon cation C 32H 14+ as a first necessary check for the "strong" PAHs hypothesis. In this paper we derive a quantitative relation between the intensities of the former band, which ought to be observable in absorption in the visible range, and those of the far-IR bands, which are predicted by the PAH model to be simultaneously present in emission. Contrary to the mid-IR bands, collectively known as "Unidentified Infrared Bands" (UIBs), which do not discriminate specific molecules, the far IR, skeletal bands can be expected to be a fingerprint of each single species. This fact provides a number of independent constraints which must be simultaneously fulfilled for a successful PAH identification. Our approach thus offers a powerful criterion for the identification of specific PAHs, both in the presently available ISO data and in those of the forthcoming SIRTF and Herschel missions. As an interesting by-product, we quantitatively evaluate the impact of isotopic substitutions ( 13 C-12 C) on the resulting infrared emission bands.
Keywords :
lines and bands , molecules , Infrared , astrochemistry , line , Identification , ISM , molecular processes
Journal title :
Astronomy and Astrophysics
Journal title :
Astronomy and Astrophysics