abstract for Lab Astro Workshop

[joe@physics.gmu.edu]

Title:
 
Photoelectric Emission from Dust Grains Exposed to
Extreme Ultraviolet and X-ray Radiation
 
Author(s):
 
Joseph C. Weingartner
Bruce T. Draine
David K. Barr
 
Abstract:
 
Photoelectric emission from dust plays an important role in grain
charging and gas heating.  To date, detailed models of these processes
have focused primarily on grains exposed to soft radiation fields.
We provide new estimates of the photoelectric yield for neutral and
charged carbonaceous and silicate grains, for photon energies exceeding
20 eV.  We include the ejection of electrons from both the band
structure of the material and the inner shells of the constituent atoms,
as well as Auger and secondary electron emission.  We apply the model
to estimate gas heating rates in planetary nebulae and grain charges
in the outflows of broad absorption line quasars.  For these applications,
secondary emission can be neglected; the combined effect of inner shell
and Auger emission is small, though not always negligible.  Finally, we
investigate the survivability of dust entrained in quasar outflows.

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Registration form for Lab Astro Workshop
 
Last name:              Weingartner
First name:             Joseph
Middle name/initial:    C.
Affiliation:            George Mason University
                        Department of Physics and Astronomy
Street Address:         4400 University Drive, MSN 3F3
City:                   Fairfax
State:                  VA
Postal Code:            22030
Country:                USA
Tel:                    703-993-4596
Fax:                    703-993-1269
E mail:                 joe@physics.gmu.edu
Citizenship*:           USA
Abstract title          Photoelectric Emission from Dust Grains Exposed to
                        Extreme Ultraviolet and X-ray Radiation
Special requirements:   None