Exploring the evolution of engagement between academic public health researchers and decision-makers : from initiation to dissolution

This chapter focuses on the chemistry of the PAHs in a circumstellar disk and on its effects on the mid-IR emission, as well as on the differences between disks around Herbig Ae/Be

3 The chemical history of molecules in circumstellar disks II: Gas-phase species 59 3.1

We also see a lot of envelope material hitting the outer parts of the disk in our semi-analytical collapse model, but there is still a fair amount (up to 50%) that makes its way to

Figure 2.3 – Dust temperature due to the accretion shock (vertical axis) and stellar radiation (hor- izontal axis) at the point of entry into the disk for 0.1-µm grains in a sample

For example, it was already known that the collapse-phase chemistry is dominated by a few key chemical processes and that the collapsing core never attains chemical equilibrium

The 2D treatment of the accretion results in material accreting at larger radii, so a smaller fraction comes close enough to the star for amorphous silicates to be thermally

Figure 5.7 – Histogram of the absolute relative difference between the approximate method (see text for details) and the full computation for the absolute photodissociation rates

A disk around a Herbig Ae/Be star containing PAHs of 50 or 96 carbon atoms shows strong PAH features, but the 24-C spectrum contains only thermal dust emission.. The goal