Collaborative Research: Submillimeter Studies of the Cosmological Star Formation and AGN Histories

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

AST-0084847 Barger, Amy J. Submillimeter Studies of the Cosmological Star Formation and AGN Histories This work has as its goal the analysis of new information about the dust-obscured star formation and AGN activity at high-redshifts which was recently discovered with the Submillimeter Common User Bolometer Array (SCUBA) on the 15 m James Clark Maxwell Telescope (JCMT) in Hawaii. The project scientists plan to extend their observations to cover galaxy counts for sources in the flux range of 0.5 to 20 mJy at submillimeter wavelengths. They expect these low flux sources to comprise the bulk of the light seen in the far infrared background. They will use deep centimeter radio maps from the VLA and hi-resolution, hard x-ray images from the Chandra satellite to determine the multi-wavelength properties of these distant, heavily dust-obscured sources. This data in turn will be used to identify objects for further study with the Keck, Subaru, and Gemini telescopes. These studies focus on the properties of galaxies during an interval of cosmic time when most of the stars we see today were being formed. In the early stages of formation, stars are enshrouded in dust and this dust blocks visible light. However, very energetic electromagnetic radiation, such as X-rays, or very low energy radiation, such as submillimeter (far infrared) or radio waves can penetrate the dust and allow us to "see" the stars as they form. The newly developed "SCUBA" detector at the 15 m JCMT in Hawaii can be used to detect very faint submillimeter sources, which may be dust enshrouded stars (starbursts) or may be active galactic nuclei (AGNs), by using intervening clusters of galaxies to "lens", or enhance the brightness, of the faint sources. By combining these observations with ones in the X-ray region (from the Chandra satellite) and other observations in the radio region (using the VLA) Cowie and Barger will be able to sort out the starbursts from the AGNs and determine the relative importance of the two types of activity for galaxies in the early stages of evolution. Funding for this project was provided by the NSF program for Extragalactic Astronomy & Cosmology (AST/EXC). ***