Lucy M. Ziurys
B.S. 1978, Rice University
Ph.D. 1984, U. C. Berkeley
Phone: (520) 621-6525
Fax: (520) 621-5554
At present, more than 100 different chemical species have been detected in interstellar space, primarily in giant gas clouds
scattered throughout our Galaxy. The objectives of my research are to study these molecules and their chemistry via an
interdisciplinary approach that involves both high resolution molecular spectroscopy in the laboratory and observational
techniques of radio astronomy. The work primarily concerns (1) laboratory spectroscopy of potential interstellar molecules
and (2) observational studies of these molecules using radio telescopes.
The aim of the laboratory research is to measure the gas-phase rotational spectra of the species of interest in the millimeter/
sub-millimeter region of the electromagnetic spectrum (~60-600 GHz). This goal requires design and construction of our own
direct absorption spectrometer systems. Also, the physical conditions in interstellar gas are quite different from those of Earth,
being much colder (10-100 K) and having significantly lower densities (~104-106 particles/cc).
Hence, interstellar molecules
are usually species that are short-lived here on Earth, namely free radicals and molecular ions. Therefore, part of the
laboratory work concerns developing exotic synthetic techniques for creating these transient species in detectable
concentrations. Of interest are small molecules that contain the cosmically abundant metals such as magnesium, iron, and
aluminum. Up to the present, we have succeeded in recording the spectra of a variety of metal-bearing hydride, hydroxide,
cyanide, acetylide, methyl, and carbide radicals, including MgOH, AlCH3, MgCN, CaCCH, FeF, and FeC. (See Figure 1).
Almost all of these species have unpaired electrons, and thus their spectra exhibit fine and hyperfine splittings. Analysis of
such data requires a detailed knowledge of quantum mechanics and the coupling of angular momentum.
The ratio astronomy aspect of this research program principally concerns the detection of new interstellar molecules, which
is achieved by observing their pure rotational spectra using millimeter and sub-mm wave telescopes. Thus, the measurements
obtained in our laboratory are directly employed in the identification of these species in astronomical sources. For example,
we have recently detected a new interstellar molecule, MgCN, towards the late-type carbon star IRC+10216. Observations of
the molecules are conducted at various sites, including the National Radio Astronomy Observatory 12 meter telescope located
on Kitt Peak in Arizona, the IRAM 30 m telescope near Granada, Spain, and the new Sub-millimeter Telescope (SMT) on
Mount Graham, also in Arizona. From the interstellar spectra, the abundance and distribution of a given chemical species can
be determined. The combined laboratory and observational data provide unique insights into
astrochemical processes that occur in the interstellar medium.
- "Fourier Transform Microwave Spectroscopy of HZnCN
(Χ1Σ+) and ZnCN (Χ2Σ+)," M.Sun, A.J. Apponi, and L.M.
Ziurys, J. Chem.
Phys., 034309 (2009). Reprint
- "Molecular Survival in Evolved Planetary Nebulae: Detection of H2CO
and CCH in the Helix," E.D. Tenenbaum, S.N. Milam, N.J. Woolf, and L.M. Ziurys, Ap.J. (Letters), 704 L108 (2009).
- "Exoctic Metal Molecules in Oxygen-Rich Envelopes: Detection of AIOH
(Χ1Σ+) in VY Canis Majoris," E.D. Tenenbaum and L.M.
Ziurys, Ap.J.(Letters), 712,
L93 (2010). Reprint
- "Comparative Spectra of Oxygen-Rich vs. Carbon-Rich Circumstellar Shells: VY Canis Majoris and IRC+10216
at 215-285 GHz," E.D. Tenenbaum, J.L. Dodd, S.N. Milam, N.J. Woolf, and L.M. Ziurys, Ap.J. (Letters) 720, L102
- "Millimeter/Sub-Millimeter Velocity Modulation Spectroscopy of FeO+
(Χ6Σ+): Characterizing Metal Oxide Cations," D.T. Halfen and L.M. Ziurys, Chem. Phys.
Letters, 496, 8 (2010). Reprint
- "The Arizona Radio Obseratory 1mm Spectral Survey of IRC+10216 and VY Canis Majoris." E.D. Tenenbaum,
J.L. Dodd, S.N. Milam, N.J. Woolf, and L.M. Ziurys, Ap.J. Suppl., 190, 348 (2010). Reprint
- "Activation of CH4 by Zinc: Gas-Phase Synthesis, Structure, and Bonding in
HZnCH3," M.A. Flory, A.J. Apponi, L.N. Zack, and L.M. Ziurys, J. Am. Chem. Soc., 132, 17186 (2010). Reprint
- "The Rotational Spectrum of CuCCH (Χ1Σ+): A Fourier
Transform Microwave DALAS and Millimeter/Sub-Millimeter Study," M. Sun, D.T. Halfen, J. Min, B. Harris, D.J.
Clouthier, and L.M. Ziurys, J. Chem. Phys., 133, 174301 (2010). Reprint
- "Iron-Containing Molecules in Circumstellar Envelopes: Detection of FeCN (Χ4Δi) in
IRC+10216," L.N. Zack, D.T. Halfen, and L.M. Ziurys, Ap.J., 730, L36
- "Fourier Transform Microwave Spectroscopy of FeCN (Χ4Δi)
: Confirmation of the Quartet Electronic Ground State," L.N. Zack, J. Min, B.J. Harris, M.A. Flory, and L.M. Ziurys,
Chem. Phys. Letters, 514, 202 (2011)