Light from distant objects transverses through interstellar clouds comprised of warm, partially ionized gas causing extinction. The Sun itself is embedded in a complex amalgamation of these clouds known as the Local Interstellar Medium (LISM). Observations using the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope have provided high resolution near ultraviolet (NUV) spectra should MgII, FeII, and in some cases, MnII absorption due to the LISM. Spectra were analyzed for the sightlines towards 34 stars within 100 parsecs spanning the entire sky. The heavy ions studied in this survey produce narrow absorption features, making the identification of multiple LISM components within an individual sightline possible. Simultaneous fits of the MgII and FeII doublets show anywhere from one to five discrete absorption features per sightline. Furthermore, characteristics of the absorption features (centroid, width, and depth) reveal the physical parameters (radial velocity, Doppler parameter, and column density) of the clouds themselves. The majority of the components identified are well correlated to previous LISM studies conducted by Redfield &Linsky in 2008 and Malamut et al. in 2014, 13 sightlines show evidence for previously unidentified clouds within the LISM. These measurements will add to a growing data set of 191 NUV sightlines probing the LISM. The addition of the 34 sightlines in this survey will test and refine the current dynamical model of the LISM. Additionally, many of the sightlines analyzed in this survey have been previously observed and analyzed in the far UV, providing lighter ion fits for LISM. This information combined with the heavy ion fits from this survey will provide constraints which allow the measurement of additional physical properties of the LISM such as temperature, turbulence, abundances, and depletion.
"},{"label":"Degree","value":["Bachelor of Arts with Departmental Honors"]},{"label":"Author-supplied Keywords","value":["Interstellar medium","Spectra","Dynamical model"]},{"label":"Administrative Note","value":"Drupal Node ID: 24120