THEMIS

THEMIS grids

The extinction (EXT_xx.RES files) and emission (SED_xx.RES files) spectra were computed with the DustEM numerical tool using the Mathis et al. (1983) radiation field, scaled by the factor G₀ ∈ [0.1, 100]. The spectra are given on a grid containing 800 steps between 0.04 and 10⁵ μm.

The emission files contain the the emission per proton for each grain population 4πνI_ν/N_H in erg/s/H as a function of wavelength (N_H is the proton column density). The grain populations are labelled with the following names:

CM20: carbonaceous grains as defined in Jones et al. (2013). Grains up to 20 nm consist purely of aromatic-rich H-poor amorphous carbon, a-C, whereas bigger grains have a core/mantle structure, where the core is made of aliphatic-rich H-rich carbon, a-C:H, and the mantle of a-C with a thickness of 20 nm,
aOlM5 + aPyM5: silicates as defined in Koehler et al. (2014). These core/mantle grains consist of amorphous silicate cores (olivine and pyroxene-normative composition, Mg-rich) and 5 nm mantles of a-C.

The extinction files contain the extinction cross-section (σ_abs+σ_sca) for each grain population per gram of dust type. The total optical depth and extinction are then (see the DustEM userguide):
τ(λ) = ∑_tt (σ_abs^tt+σ_sca^tt) M_tt/M_H m_H N_H
A_λ = 1.086 × τ(λ).

The size distribution files (SDIST_xx.RES) were also computed with DustEM and contain the mass distribution (a³ dn/dlna in cm³/H) as a function of the effective grain radius a in microns.

CM grains

♣ CM extinction spectrum → here
♣ CM emission spectrum for G₀ = 1 → here
♣ CM temperature distribution for G₀ = 1 → here
♣ CM size distribution → here
♣ CM emission spectra for G₀ ∈ [0.1, 100] → here

CMM grains

Coming soon!

AMM grains

Coming soon!

AMMI grains

Coming soon!