Event Title

Modeling the Effect Black Holes Have on the Morphologies of Their Host Galaxies in the Early Universe

Location

Davis 301

Start Date

30-4-2015 9:00 AM

End Date

30-4-2015 10:55 AM

Project Type

Presentation

Description

The effect that Active Galactic Nuclei (AGN) have on the morphology of galaxies was studied by adding point sources of light to distant galaxies absent of an AGN. An active galactic nuclei is a black hole at the center of a galaxy that is radiating extreme amounts of light due to a high influx of matter into the black hole. The galaxies studied were imaged by the Hubble Space Telescope and selected to have a redshift value between z = 1.5 and z = 2.5. Galaxies with host AGN were ruled out based on X-ray imaging from the Chandra Space Telescope over the same region of space. Within these parameters, 13 galaxies were selected representing both elliptical and spiral galaxies. These galaxies were classified and modeled using the program GALFIT to gain measurements of both the sersic index of the light profile of the galaxy, n, and the effective radius of the galaxy, Re. A point source of light was added to the image of each galaxy at 10%, 20%, 30%, 40%, and 50% of the total light of the galaxy, in turn modeling the appearance of an AGN at different intensities. The images with added AGN were modeled again with the program GALFIT to gain measurements of the sersic index and effective radius. The presence of the modeled AGN were found to increase the sersic index while generally causing a decrease in the effective radius.

Faculty Sponsor

Duncan Tate

Sponsoring Department

Colby College. Physics and Astronomy Dept.

CLAS Field of Study

Natural Sciences

Event Website

http://www.colby.edu/clas

ID

1579

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Apr 30th, 9:00 AM Apr 30th, 10:55 AM

Modeling the Effect Black Holes Have on the Morphologies of Their Host Galaxies in the Early Universe

Davis 301

The effect that Active Galactic Nuclei (AGN) have on the morphology of galaxies was studied by adding point sources of light to distant galaxies absent of an AGN. An active galactic nuclei is a black hole at the center of a galaxy that is radiating extreme amounts of light due to a high influx of matter into the black hole. The galaxies studied were imaged by the Hubble Space Telescope and selected to have a redshift value between z = 1.5 and z = 2.5. Galaxies with host AGN were ruled out based on X-ray imaging from the Chandra Space Telescope over the same region of space. Within these parameters, 13 galaxies were selected representing both elliptical and spiral galaxies. These galaxies were classified and modeled using the program GALFIT to gain measurements of both the sersic index of the light profile of the galaxy, n, and the effective radius of the galaxy, Re. A point source of light was added to the image of each galaxy at 10%, 20%, 30%, 40%, and 50% of the total light of the galaxy, in turn modeling the appearance of an AGN at different intensities. The images with added AGN were modeled again with the program GALFIT to gain measurements of the sersic index and effective radius. The presence of the modeled AGN were found to increase the sersic index while generally causing a decrease in the effective radius.

http://digitalcommons.colby.edu/clas/2015/program/351