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2013 Master's Level Graduate Research Conference

Session I - Session II - Session III

Feedback in the Local Universe: The Relation Between Star Formation and AGN Activity in Typical Elliptical Galaxies

Aim: The project address the relation between star formation and AGN activity in a large sample of nearby early type (E and S0) galaxies. Feedback from the AGN is believed to play an important role in regulating star formation. Earlier studies of AGN feedback have focused on large systems, i.e. cooling flow clusters and/or X-ray selected sources and none of the studies looked at the relation between star formation and AGN activity in typical elliptical galaxies.
 Methods: The project is carried out at multi-wavelength with a sample of 236 elliptical galaxies which were chosen to have an apparent K magnitude brighter than 13.5 and whose positions correlate with Chandra ACIS-I and ACIS-S sources. The galaxies in the sample are unbiased regarding their star formation and radio source properties. Using the archival observations at radio, ultraviolet and infrared from VLA, GALEX and WISE respectively, the radio power, GALEX FUV - 2MASS K and WISE infrared color to study AGN activity and star formation is obtained.
 Results: There is an upper envelope of radio power that is a steep function of absolute K-band magnitude of the galaxy suggesting that the maximum possible jet power is dependent on the brightness of the galaxy and thus on the mass of the galaxy. A color-color diagram between (FUV-K) vs (FUV-NUV) shows the presence of bluer galaxies indicating that star formation is present in the sample. Radio power and FUV-K color is uncorrelated suggesting that perhaps fueling of radio sources is not associated with substantial star formation or perhaps the radio jets have suppressed star formation. All the star forming galaxies identified in the sample are less massive and faint in radio. Hot dust is observed in only a small subset of the objects, suggesting that in most of the galaxies, any AGNs are accreting in a process that is radiatively inefficient. In a subset of galaxies, much of the star formation is obscured by dust.

Topic: Astronomy -Panel
Location: 102 Edwards
Time: 9 am (Session I)