Looking for the Wind in the Dust

TL;DR

This paper investigates the role of radiation driving in quasar winds beyond the dust sublimation radius by modeling infrared spectral energy distributions with a 3D hydrodynamic wind model, highlighting the significance of dust in these outflows.

Contribution

It demonstrates that radiation driving on dust can explain infrared features like the 3-5 micron bump and silicate emissions in quasars using a dynamical wind model.

Findings

Reproduces the 3-5 micron bump with the wind model.

Predicts broad silicate features consistent with observations.

Supports radiation driving as a key mechanism in quasar winds.

Abstract

The blue-shifted broad emission lines and/or broad absorption lines seen in many luminous quasars are striking evidence for a broad line region in which radiation driving plays an important role. We consider the case for a similar role for radiation driving beyond the dust sublimation radius by focussing on the infrared regime where the relationship between luminosity and the prominence of the 3-5 micron bump may be key. To investigate this further, we apply the 3D hydrodynamic wind model of Everett (2005) to predict the infrared spectral energy distributions of quasars. The presence of the 3-5 micron bump and strong, broad silicate features can be reproduced with this dynamical wind model when radiation driving on dust is taken into account.