Abstract
Speaker: Miller Goss
Title: The Thermally Unstable Warm Neutral Medium: Key for Modeling the ISM
Abstract: We have recently undertaken a pilot project with the EVLA to search for HI absorption against a sample of continuum sources along line of sights which indicated the existence of thermally unstable warm neutral medium. This pilot project have successfully demonstrated that high enough bandpass stability can be achieved with the EVLA to detect HI absorption lines with the optical depth sensitivity of 10−3. Our sensitive observations enabled us to detect HI absorption along some line of sights which were undetected in previous emission/absorption surveys. In this talk we will present our measurements and discuss their implications on the fraction of interstellar medium in the thermally unstable regime.