Amorphous carbons and extinction curve

Rakesh, K.; Botet, Robert

doi:10.1093/mnras/stu1401

“…This is also hinted by the numerical tendency during the fitting procedure to go below the lowest limit of 5 nm in particle size, that is systematic for all the lines of sight in the MWG and in the MCs. Such small particles might be carbon mantle fragments, possibly produced during some destructive events (as discussed in the previous paragraph), such as e. g. nanodiamonds (Rai & Rastogi 2010, 2012Rai & Botet 2014).…”

Section: Discussionmentioning

confidence: 99%

Modelling dust extinction in the Magellanic Clouds

Zonca,

Casu,

Mulas

et al. 2015

Preprint

0

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We model the extinction profiles observed in the Small and Large Magellanic clouds with a synthetic population of dust grains consisting by core-mantle particles and a collection of free-flying polycyclic aromatic hydrocarbons. All different flavors of the extinction curves observed in the Magellanic Clouds can be described by the present model, that has been previously (successfully) applied to a large sample of diffuse and translucent lines of sight in the Milky Way. We find that in the Magellanic Clouds the extinction produced by classic grains is generally larger than absorption by polycyclic aromatic hydrocarbons. Within this model, the non-linear far-UV rise is accounted for by polycyclic aromatic hydrocarbons, whose presence in turn is always associated to a gap in the size distribution of classical particles. This hints either a physical connection between (e.g., a common cause for) polycyclic aromatic hydrocarbons and the absence of middle-sized dust particles, or the need for an additional component in the model, that can account for the non-linear far-UV rise without contributing to the UV bump at ∼217 nm, e.g., nanodiamonds.

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“…This is also hinted by the numerical tendency during the fitting procedure to go below the lowest limit of 5 nm in particle size, that is systematic for all the lines of sight in the MWG and in the MCs. Such small particles might be carbon mantle fragments, possibly produced during some destructive events (as discussed in the previous paragraph), such as e. g. nanodiamonds (Rai & Rastogi 2010Rai & Botet 2014).…”

Section: (23)mentioning

confidence: 99%

Modeling Dust in the Magellanic Clouds

Zonca

¹

,

Casu

²

,

Mulas

³

et al. 2015

ApJ

View full text Add to dashboard Cite

We model the extinction profiles observed in the Small and Large Magellanic clouds with a synthetic population of dust grains consisting by core-mantle particles and a collection of free-flying polycyclic aromatic hydrocarbons. All different flavors of the extinction curves observed in the Magellanic Clouds can be described by the present model, that has been previously (successfully) applied to a large sample of diffuse and translucent lines of sight in the Milky Way. We find that in the Magellanic Clouds the extinction produced by classic grains is generally larger than absorption by polycyclic aromatic hydrocarbons. Within this model, the non-linear far-UV rise is accounted for by polycyclic aromatic hydrocarbons, whose presence in turn is always associated to a gap in the size distribution of classical particles. This hints either a physical connection between (e.g., a common cause for) polycyclic aromatic hydrocarbons and the absence of middle-sized dust particles, or the need for an additional component in the model, that can account for the non-linear far-UV rise without contributing to the UV bump at ∼217 nm, e.g., nanodiamonds.

show abstract