Rubidium in the Interstellar Medium (2009)
Walker, Kyle M., Federman, S. R., Knauth, David C., Lambert, David L.
We present observations of interstellar rubidium toward o Per, zeta Per, AE Aur, HD 147889, chi Oph, zeta Oph, and 20 Aql. Theory suggests that stable 85Rb and long-lived 87Rb are produced...
The Interstellar N/O Abundance Ratio: Evidence for Local Infall? (2006)
Knauth, David C., Lauroesch, James T., Meyer, David M.
Sensitive measurements of the interstellar gas-phase oxygen abundance have revealed a slight oxygen deficiency ($\sim$ 15%) toward stars within 500 pc of the Sun as compared to more distant...
INTERSTELLAR N$_2$ IN THE DIFFUSE ISM TOWARD 20 AQUILAE (2005)
Knauth, David C., McCandliss, S. R., Moos, H. W.
Author Institution: Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208; Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218
The Interstellar Rubidium Isotope Ratio toward Rho Ophiuchi A (2004)
Federman, S. R., Knauth, David C., Lambert, David L.
The isotope ratio, 85Rb/87Rb, places constraints on models of the nucleosynthesis of heavy elements, but there is no precise determination of the ratio for material beyond the Solar System. We report...
Potential Variations in the Interstellar N I Abundance (2003)
Knauth, David C., Andersson, B-G, McCandliss, Stephan R., Moos, H. Warren
We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope Imaging Spectrograph observations of the weak interstellar N I doublet at 1160 Angstroms toward 17 high-density sight...
On the Origin of the High-Ionization Intermediate-Velocity Gas Toward HD 14434 (2003)
Knauth, David C., Howk, J. Christopher, Sembach, Kenneth R., Lauroesch, James T., Meyer, David M.
We present Far Ultraviolet Spectroscopic Explorer and Space Telescope Imaging Spectrograph observations of high-ionization interstellar absorption toward HD 14434 [(l, b) = (135.1, -3.8); d ~ 2.3...
Hoopes, Charles G., Sembach, Kenneth R., Hebrard, Guillaume, Moos, H. Warren, Knauth, David C.
We have carried out an investigation of the abundance of deuterium along two extended sight lines through the interstellar medium (ISM) of the Galactic disk. The data include Far Ultraviolet...
Knauth, David C., Federman, S. R., Lambert, David L.
In an effort to probe the extent of variations in the interstellar ^7Li/^6Li ratio seen previously, ultra-high-resolution (R ~ 360,000), high signal-to-noise spectra of stars in the Perseus OB2 and...
Knauth, David C., Federman, S. R., Pan, K., Yan, M., Lambert, David L.
High resolution optical spectra of HD 37903 and HD 147009, which illuminate the reflection nebulae, NGC 2023 and vdB 102, were obtained for comparison with our results for HD 200775 and NGC 7023....
Oscillator Strengths for B-X, C-X, and E-X Transitions in Carbon Monoxide (2001)
Federman, S. R., Fritts, M., Cheng, S., Menningen, K. M., Knauth, David C., Fulk, K.
Band oscillator strengths for electronic transitions in CO were obtained at the Synchrotron Radiation Center of the University of Wisconsin-Madison. Our focus was on transitions that are observed in...
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Evidence for Newly Synthesized Lithium in Interstellar Space (2000)
Knauth, David C., Federman, Steven R., Lambert, David L., Crane, Phillipe
As a part of a study on the variation in the 7Li/6Li ratio, high signal to noise, high resolution spectroscopy of Li I (6708 Angstroms) and K I (4044 Angstroms) were obtained toward zeta and o Per....