Prof. Stanimirovic Receives NSF CAREER Award

Oct 03, 2011

Department of Astronomy Professor Snezana Stanimirovic was recently awarded a National Science Foundation (NSF) CAREER Award for a 5-year study entitled "Diffuse interstellar clouds as the key step in galaxy evolution." This prestigious award supports junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education, and the integration of education and research within the context of their organization’s mission.

Stanimirovic's study aims at understanding the very first step in the formation of stellar and planetary systems—the transformation of diffuse interstellar gas into cold, dense clouds. Recent observational studies suggest that such clouds form stars at a constant efficiency, implying that cloud formation plays a crucial role in galaxy evolution. To investigate how star-forming clouds form out of the warm neutral medium, Stanimirovic and her students will use two next-generation radio facilities for sensitive HI absorption observations of the Milky Way and the Magellanic Clouds.

The "21-SPONGE" survey is using the Expanded Very Large Array (EVLA) to provide the first quantitative description of the basic physical properties of the warm neutral medium in the Milky Way. Stanimirovic is leading a team of scientists from the National Radio Astronomy Observatory, UC-Berkeley, University of Tasmania (Australia) and Paris Observatory to measure the temperature and abundance of the warm neutral medium. These observational diagnostics are crucial for constraining theoretical and numerical models of how warm atomic gas transforms into future stellar nurseries. "These measurements require extremely sensitive radio interferometers and were essentially impossible before the recent upgrade of the VeryLarge Array," says Stanimirovic. "Over the past two years we have obtained pilot observations with the EVLA to ensure that everything is ready for 21-SPONGE. Since January, observations in progress have taken advantage of, or ‘sponged’ away, any gaps in the EVLA observing schedule during array configuration moves."

The second survey, Galactic ASKAP (GASKAP), will be conducted with the Australia SKA Pathfinder, a new radio telescope being built in Australia. One of the science goals of this large international collaboration is to provide the census and properties of cold and warm gas in the Magellanic Clouds, probing interstellar conditions unusual for the Milky Way but typical for galaxies in the early Universe. Results from both surveys will be compared with synthetic spectra derived from numerical simulations to study the formation of star-forming clouds and to test the reliability of simulated data sets.

The educational component of this CAREER award focuses on the exploration of interstellar clouds in the Milky Way in introductory astronomy classes with several small radio telescopes. One radio telescope is already on the roof of Sterling Hall and is getting ready for its first observations thanks to the Astronomy Department's electronics shop. "Once telescopes are operational, we will develop simple tutorials that will allow students from introductory astronomy classes to conduct observations and analyze their spectra," says Stanimirovic. The long-term plan is to provide a remote setup so that undergraduate students from other UW campuses can remotely control radio telescopes from their classrooms and work with the radio tutorials.

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