Mentors: Marco Ajello & Masaaki Hayashida Probing the Geometry and Physics of the Emission Region of Active Galactic Nuclei Using Hard X-Ray Observations Natasha Woods Mentors: Marco Ajello & Masaaki Hayashida

Outline AGN & Unified Model Testing the Unified Model Results Conclusions

Introduction AGN Classification Majority of energy output unrelated to stellar processes Compact regions, galaxy center, exceedingly luminous Classification Radio luminosity Spectral properties

Unified Model for AGN All AGN are intrinsically the same Perceived differences due to viewing orientation SMBH, accretion disk, molecular torus, corona

Seyfert Galaxies

Evidence For & Against the Unified Model Polarized broad emission lines in Sy2 Sy1 <---> Sy2 Electron temperature Fraction of absorbed sources

X-ray Spectra X-Rays IC Radiation Direct, Transmitted, Reflected

Reflection Component IC reflection peak ~30keV, softening spectra (whiteboard) Sy1 should have a larger reflection component and photon index than Sy2

High Energy Cut-off Corona's electrons expected to be thermal Cut-offs for Sy1 and Sy2 should be compatible, corona's properties are independent of orientation

Relevance ~100% CXB Constrain cosmological models and black hole physics

Sample Population ~200 sources Swift-BAT hard X-ray Survey 5 sigma significance level 3 years exposure Unbiased, blind search

Models for Spectra Simple power law model (SPL) fit to individual spectra in Xspec11

Photon Index Histograms

Gaussian and Weighted Averages Gaussian poorly fit some data Weighted Averages based on errors no model

Stacked Spectra S/N, mean properties SPL and PEXRAV fit to spectra

Results: SPL Histograms (KS p-values)

Results: SPL & PEXRAV Stacked Spectra PEXRAV>SPL Photon Indices Reflection Energy Cut- off

Conclusion Photon Index Sy1 > Sy2 PEXRAV > SPL Reflection compatible, large errors Energy Cut-offs different Future

Acknowledgements