Absorption Line Spectroscopic Studies of the Interstellar Medium

Warm (5,000-10,000 K) gas in the interstellar medium is seen only in isolated clouds that can be identified by their kinematics, temperatures, and metal depletions on to grains. High resolution HST and FUSE spectra covering the 912-3000 A region contain many absorption lines formed in warm clouds. The Sun is located just inside one such cloud, the Local Interstellar Cloud (LIC), and within 100 pc of the Sun there are other clouds with different kinematic and physical properties. We are building a three-dimensional model of the warm gas clouds within 100 pc of the Sun and developing models for the ionization balance of these clouds. See the Webpage of the Colorado Model of the Local Interstellar Cloud. A view of the LIC looking down from the North Galactic Pole showing that the Sun (located at 0,0) lies barely inside the LIC.

Research Objectives:

• Model the structure and kinematics of warm clouds in the interstellar medium out to about 100 pc.
• Determine the physical properties (temperature, density, and ionization state) of warm clouds in the local interstellar medium.
• Determine the chemical abundances and depletions of warm clouds in the local interstellar medium.
• Study the interaction of stellar winds with the local ISM that forms hydrogen walls and astrospheres around stars.

Recent Publications:

• Linsky, J.L., Mobius, E., Izmodenov,V.V., and von Steiger,R. (eds.): 2009, "From the Outer Heliosphere to the Local Bubble", Space Sciences Series of ISSI, Springer
• Linsky, Jeffrey L.: 2009, "Understanding Physical Processes in the Diffuse Interstellar Medium Using High-Resolution UV Spectroscopy", poster at the Beyond JWST: the Next Steps in UV-Optical-NIR Astronomy"
• Linsky, Jeffrey L.: 2009, "Solving the Mysteries of the Diffuse Interstellar Medium with High-Resolution Spectroscopy", Astrophysics and Space Science, 320, 85
• Linsky, Jeffrey L., Rickett, Barney J., and Redfield, Seth: 2008, "The Origin of Radio Scintillation in the Local Interstellar Medium", Astrophysical Journal, 675, 413
• Redfield, Seth and Linsky, Jeffrey L.: 2008, "The Structure of the Local Interstellar Medium. IV. Dynamics, Morphology, Physical Properties, and Implications of Cloud-Cloud Interactions", Astrophysical Journal, 673, 283
• Redfield, S., Wood, B.E., and Linsky, J.L.: 2004, "Physical structure of the local interstellar medium",Advances in Space Research, 34, 41
• Redfield, S., and Linsky, J.L.: 2004, "The structure of the Local Interstellar Medium. III. Temperature and turbulence", Astrophysical Journal, 613, 1004
• Redfield, S., and Linsky, J.L.: 2004, "The structure of the Local Interstellar Medium. II. Observations of D I, C II, N I, O I, Al II, and Si II toward stars within 100 parsecs", Astrophysical Journal, 602, 776
• Wood, B.E., Redfield, S., Linsky, J.L., and Sahu, M.S.: 2002, "Elemental abundances and ionization states within the Local Interstellar Cloud derived from HST and FUSE observations of the Capella line of sight", Astrophysical Journal, 581, 1168
• Linsky, J.L.: 2002, "Constructing physically realistic models of the interstellar gas: Start with understanding the physics of the local ISM", in Hubble Science Legacy Workshop, ed. K. Sembach, et al, ASP Conf. Series, 291, 188
• Redfield, S., and Linsky, J.L.: 2002, "The structure of the Local Interstellar Medium. I. High-resolution observations of Fe II, Mg II, and CaII toward stars within 100 parsecs", Astrophysical Journal Supplement Series, 139, 439
• Redfield, S., and Linsky, J.L.: 2001, "Microstructure of the Local Interstellar Cloud and the identification of the Hyades Cloud", Astrophysical Journal, 551, 413
• Moos, H.W. et al (including Linsky, J.L.), 2000: "Overview of the Far Ultraviolet Explorer Mission", Astrophysical Journal Letters, 538, L1
• Jenkins, E.B., et al (including Linsky, J.L.), 2000, "The ionization of the local interstellar medium as revealed by FUSE observations of N, O, and Ar toward white dwarf stars", Astrophysical Journal Letters, 538, L81
• Linsky, J.L., Redfield, S., Wood, B.E., and Piskunov, N.: 2000, "The three dimensional structure of the warm local interstellar medium. I. Methodology", Astrophysical Journal, 528, 756
• Redfield, S., and Linsky, J.L.,: 2000, "The three dimensional structure of the warm local interstellar medium. II. The Colorado model of the local interstellar cloud (LIC), Astrophysical Journal, 534, 825
• Wood, B.E., Linsky, J.L., and Zank, G.P.: 2000, "Heliospheric, astrospheric, and interstellar Lyman-alpha absorption toward 36 Oph", Astrophysical Journal, 537, 304
• Wood, B.E., Ambruster, C.W., Brown, A., and Linsky, J.L.: 2000, "The MgII and Lyman Alpha lines of nearby K dwarfs: Interstellar medium components and flux measurements", Astrophysical Journal, 542, 411
• Linsky, J.L., Redfield, S., and Wood, B.E.: 2000, "The warm local ISM: structure, properties, and theory", invited talk at the Fourth Tetons Summer Conference: Galactic Structure, Stars and the Interstellar Medium, Jackson Hole WY, May 28-June 1, 2000, ASP 231, 337
• Linsky, J.L., Redfield, S., and Wood, B.: 2000, "Components of the local interstellar medium", invited talk at IAU Symposium 203, Recent Insights in to the Physics of the Sun and Heliosphere, Manchester England, Aug 7-11, 2000, Astronomical Society of the Pacific Conference Series, 200, 595