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“The Dynamical Structure of the Local Interstellar Medium” Dr. Seth Redfield University of Texas at Austin |
| The local interstellar medium (LISM) provides an opportunity to study general ISM processes in great detail and in three dimensions, as well as observe how stellar and planetary systems interact with their surrounding interstellar environment (e.g., the heliosphere). The dynamical structure of the LISM is critical to understanding how warm partially ionized gas in the solar vicinity may have formed, evolves, and influences the heliosphere. High spectral resolution observations are used to derive 15 rigid velocity vectors and determine the shapes of the associated clouds located within 15 pc of the Sun. Assignment of cloud membership is not solely derived from projected velocity agreement, but also includes comparison of physical parameters (e.g., temperature, nonthermal velocity, and depletions) with nearby cloud members. Several clouds have a filamentary structure, which may be indicative of shocked or interacting material. I will discuss cloud dynamics at boundary regions and search for evidence of shear flows or cloud-cloud collisions, and explore the consequences of such interactions. In addition, I will discuss recent work that connects radio scintillation scattering screens to these very same LISM clouds. If time permits, I will discuss a project in progress: CLOSE (CaII LISM Optical Survey of our Environment), the largest homogenous survey of LISM absorption at high spectral resolution. |