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Faculty of Science

Department of Physics & Astronomy

CAP Lecture - The Biggest Blowhards: Windy Supermassive Black Holes

Description

Title: CAP Lecture - The Biggest Blowhards: Windy Supermassive Black Holes


Speaker: Dr. Sarah Gallagher


Institute: Western University


Location: JHE-264




Description:


Supermassive black holes reside in the centers of every massive galaxy including our own Milky Way. In relatively brief spurts, black holes grow as luminous quasars through the infall of material through an accretion disk. Remarkably, the light from the accretion disk can outshine all of the stars in the host galaxy by a factor of a thousand, and this radiation can also drive energetic outflows. Mass ejection in the form of winds appears to be as fundamental to quasar activity as accretion, and can be directly observed in many objects with broadened and blue-shifted UV emission and absorption features. Applying unsupervised and hierarchical clustering algorithms on quasar spectra, we can match windy quasars with specific emission-line properties sensitive to the shape of the ionizing continuum. Beyond the dust sublimation radius, radiation pressure is still important, but high energy photons from the central engine can now push on dust grains. This physics underlies the dusty wind picture for the putative obscuring torus. I'll describe our model of the dusty wind and evaluate its successes and shortcomings in accounting for observed properties of quasars such their mid-infrared power and the fraction of hidden objects.

Location information

1280 Main St W, Hamilton, ON L8S 4L8, Canada

Country
Canada
County
Ontario
City
Hamilton L8S 4L8
Street
1280 Main Street West

McMaster University - Faculty of Science

Mailing Address

Department of Physics & Astronomy,
McMaster University

ABB-241
1280 Main Street West
Hamilton, Ontario, Canada
L8S 4M1

Contact Information

Telephone Inquiries:
+1 (905) 525-9140 ext.24559
Fax:
(905) 546-1252
Email Inquiries:
physics@mcmaster.ca

McMaster University - Faculty of Science

Mailing Address

Department of Physics & Astronomy,
McMaster University

ABB-241
1280 Main Street West
Hamilton, Ontario, Canada
L8S 4M1

Contact Information

Telephone Inquiries:
+1 (905) 525-9140 ext.24558
Fax:
(905) 546-1252
Email Inquiries:
physics@mcmaster.ca