matt stevans dr. sean brittain clemson universitystevans/presentation1.pdf · herbig aebe stars...
TRANSCRIPT
Matt Stevans Dr. Sean Brittain
Clemson University
7/27/11 SARA REU 2011
Today I will talk about…
1. How planets form 2. How we study planet
formation by modeling disks 3. Results and conclusions of
my work
Planet Formation
Not to scale
Herbig AeBe Stars
7/27/11 SARA REU 2011
� Young; 2-10 Solar Masses � Flared Disks
Herbig AeBe Observables Spectral Energy Distribution (SED)
CO Emission Line Profiles in IR Excess
Mafiat 1998 Mafiat 1998
Brittain 2009
Thermal-Chemical Model Thermal Structure at Surface
Tem
pe
ratu
re (
K)
Column Density (powers of 10)
10000
5000
2000
500
200 100
18 19 20 21 22 23 24
Tgas
Tdust
α=0.01
α=2
Settled Dust at mid plane
Gaseous Surface
Disk Cross-Section Glassgold 2004
My work
� Assembled list of Herbig AeBe stars that have both CO and Brγ flux measurements.
� Reduced 9 spectra from PHOENIX at the Gemini Observatory.
7/27/11 SARA REU 2011
Observatory: Gemini
Instrument: PHOENIX
Wavelength: 1-5 microns
Resolution: ~65,000
Results � CO flux scales
with Brγ flux. � Scatter in
correlation plot can be reduced with simultaneous observations of Brγ and CO.
Brγ Flux = Mass Accretion
CO
Flu
x
Typical Error Bars
Take Away
� We cannot see into disks. � Accretion/viscous heating plays a
role in disk surface heating in inner disk.
� This needs to be incorporated into models.
Acknowledgements
7/27/11 SARA REU 2011
This project was funded by the National Science Foundation Research Experiences for Undergraduates (REU) program through grant NSF AST-1004872 Thanks to Dr. Brittain for working with me this entire summer. Thanks Thomas Rice and Charles Kurgatt for many useful discussions.
Extras
7/27/11 SARA REU 2011