Modeling Galactic Extinction with dust and "real" PAHs

4th Young Researcher Meeting, Trieste 2013

Zonca, A.^1 ; Mulas, G.^2 ; Casu, S.^2 ; Cecchi-Pestellini, C.^3

Dipartimento di Fisica, Università di Cagliari, Strada Prov.le Monserrato-Sestu Km 0.700, I-09042 Monserrato (CA), Italy^1

INAF, Osservatorio Astronomico di Cagliari, Strada n.54, Loc. Poggio dei Pini, I-09012 Capoterra, Italy^2

INAF, Osservatorio Astronomico di Palermo, P.zza Parlamento 1, I-90134 Palermo, Italy^3

关键词: Extinction curves;    Extinction profiles;    Global properties;    Grain distribution;    Interstellar dust;    Interstellar mediums;    Molecular contribution;    Molecular population;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/470/1/012009/pdf
DOI  :  10.1088/1742-6596/470/1/012009

来源: IOP

【 摘 要 】

We elaborated an interstellar dust model assuming a distribution of core-mantle grains and a collection of single polyciclic aromatic hydrocarbons. Exploiting this model, we are able to reproduce a very large sample of galactic extinction profiles with very different flavours, proving that a polyciclic aromatic hydrocarbons population can reproduce extinction curve features in the ultraviolet range. Dust grains are composed by an hollow silicatic core and a carbonaceous mantle (this description is mutuated by the cycle of carbon in the interstellar medium); molecular population is represented by 54 molecules in four charged states and, despite the large number of free parameters (we have 9 parameters to represent grain distribution and 54 × 4 column densities to reproduce the molecular contribution to the extiction), we are able to determine some global properties for molecular ensemble and we found that these properties are indipendent by specific species which we use in our model.