EDP Sciences
Free access
Volume 420, Number 3, June IV 2004
Page(s) 809 - 820
Section Astrophysical processes
DOI http://dx.doi.org/10.1051/0004-6361:20035703

A&A 420, 809-820 (2004)
DOI: 10.1051/0004-6361:20035703

Modelling photoluminescence from small particles

I. General formalism and a simple reference implementation
G. Malloci1, 2, 3, G. Mulas1, 3 and P. Benvenuti2, 4

1  INAF - Osservatorio Astronomico di Cagliari - AstroChemistry Group, Strada n.54, Loc. Poggio dei Pini, 09012 Capoterra (CA), Italy
    e-mail: gmulas@ca.astro.it
2  Dipartimento di Fisica, Università degli Studi di Cagliari, S.P. Monserrato-Sestu Km 0.7, 09042 Cagliari, Italy
3  Astrochemical Research in Space Network http://www.ars-network.org
4  INAF, Viale del Parco Mellini 84, 00136 Roma, Italy
    e-mail: benvenuti@inaf.it

(Received 17 November 2003 / Accepted 23 February 2004)

We developed a general recipe able to extrapolate the expected photoluminescence of small particles starting from available laboratory results obtained on bulk samples. We present numerical results for the simplest case, namely a spherical, homogeneous dust particle, in the limit of strongly localised fluorescence. In particular, our theoretical derivation produces an explicit, analytical, dependence of the photoluminescence spectrum on the angle between the direction of observation and that of the incoming exciting light. We expect the present model to be a useful tool that will allow the study of photoluminescence phenomena of interstellar dust to move beyond the straight, plain, possibly misleading comparison with experimental data on bulk samples.

Key words: ISM: dust, extinction -- ISM: lines and bands -- methods: numerical -- radiation mechanisms: general -- radiative transfer -- scattering

Offprint request: G. Malloci, gmalloci@ca.astro.it

© ESO 2004