Solar System Exploration Division

Brief Bio


Research Interests


Cosmic Ices

Solar System: Astrochemistry

I specialize in the study of interstellar and planetary ices, and my focus is on laboratory measurements of their physical, chemical, and spectroscopic properties. These include icy dust grain mantles found in dark interstellar clouds as well as icy materials found on the surfaces of objects within the outer Solar System (comets, icy moons, Kuiper Belt Objects, etc.).

I have used spectroscopy in different regions of the electromagnetic spectrum, such as the infrared or ultraviolet, to study the compositions of astrophysically relevant materials. Lab data help to predict and interpret observations made with astronomical observatories (such as the Spitzer or James Webb Space Telescopes) and planetary missions (such as Cassini or New Horizons). I also create laboratory analogs of interstellar and solar-system ices in order to understand the physical and chemical changes they undergo when exposed to particle radiation or high-energy photons.


Astrobiology

Solar System: Astrobiology

In work supported by the Goddard Center for Astrobiology, I have studied the survivability of amino acids glycine, alanine, and phenylalanine in icy planetary subsurfaces subjected to particle radiation (Mars, Europa, comets).  This work has been highlighted in a NASA press release from 2013 and featured on the website of the NASA Astrobiology Institute.


Spectroscopy of Astrophysical Ices

Solar System: Astrochemistry

This includes measurements of the infrared spectra of mixed molecular ices of astrophysical interest at temperatures from 10 to 300 K; the determination of parameters such as complex refractive indices (optical constants), band intensities (band strengths), and absorption coefficients. 


Infrared Observational Astronomy

Astrophysics: Interstellar Medium

Studies of dust and ice in the interstellar medium (ISM); Extinction and reddening of starlight by dust; Polarization of starlight in the ISM; Infrared absorption features due to interstellar dust and ice; the abundance of interstellar molecules in dust grain mantles; observations at international ground-based telescopes (such as the United Kingdom Infrared Telescope) and using space observatories (such as the Infrared Space Observatory and the Spitzer Space Telescope)


Planetary Exploration and Missions

Solar System: Solar System

I am a Deputy Project Scientist for the Comet Astrobiology Exploration SAmple Return (CAESAR) mission to be proposed to NASA’s New Frontiers Program. CAESAR would sample the surface of comet 67P/Churyumov-Gerasimenko and return the sample to Earth for detailed studies. It would be the farthest-reaching sample return mission in history. 

Current Projects


Cosmic Ice Laboratory

Astrochemistry


Submillimeter Spectroscopy of Sublimated Ices (SubLIME)

Astrochemistry


NASA Planetary R&A

Solar System


Postdoctoral Advisor

Astrochemistry

  • Current advisor for NASA Postdoctoral Program Fellow Yukiko Yarnall.since September 2019
  • Former advisor to NASA Postdoctoral Program Fellow Karen Smith

Education


  • 1998 -- Ph.D., Physics, Rensselaer Polytechnic Institute (Troy, NY)
  • 1995 -- Two-year Research Degree (M.S.), Astronomy, Leiden University (Leiden, the Netherlands)
  • 1993 -- B.S., Physics (minor in Astrophysics), Rensselaer Polytechnic Institute (Troy, NY)

Positions/Employment


Associate Lab Chief, Astrochemistry (Code 691)

NASA Goddard Space Flight Center - Greenbelt, MD

December 2019 - Present


Space Scientist

Astrochemistry (Code 691), NASA Goddard Space Flight Center - Greenbelt, MD

September 2010 - Present


Associate Professor (tenured)

Department of Physics, the University of Alabama at Birmingham - Birmingham, AL

October 2006 - August 2012


Assistant Professor

Department of Physics, the University of Alabama at Birmingham - Birmingham, AL

September 2000 - September 2006


Postdoctoral Research Associate

National Research Council - National Academy of Sciences - NASA Goddard Space Flight Center, Greenbelt, MD

November 1998 - August 2000

Professional Societies


American Astronomical Society (AAS)

Division for Planetary Sciences, Laboratory Astrophysics Division

1997 - Present


American Geophysical Union (AGU)

1999 - Present


International Astronomical Union (IAU)

Division B Facilities, Technologies and Data Science, Division F Planetary Systems and Astrobiology, Division H Interstellar Matter and Local Universe, Commission B5 Laboratory Astrophysics, Commission F3 Astrobiology, Commission H2 Astrochemistry

2002 - Present


American Association for the Advancement of Science (AAAS)

2016 - Present


Society of Physics Students (SPS)

1995 - Present


Asia-Oceania Geosciences Society (AOGS)

2005 - Present


American Chemical Society (ACS)

1998 - 2014

Professional Service


Regular manuscript reviewer for professional journals such as the Astrophysical Journal, Astronomy & Astrophysics, Icarus, Monthly Notices of the Royal Astronomical Society, Spectrochimica Acta, ACS Earth and Space Chemistry, Molecular Astrophysics, and Astrobiology.

Regular proposal reviewer for funding programs at NASA and the National Science Foundation (NSF).

Teaching Experience


While employed as a faculty member in the Department of Physics at the University of Alabama at Birmingham, I was the instructor for 100-level Astronomy courses (one per semester), and each course had approximately 75-100 enrolled students. I also was the instructor for undergraduate Physics courses for Physics majors, such as freshman-level Physics I & II, junior/senior-level Introductory Quantum Mechanics I & II, and graduate-level Celestial Mechanics. I mentored 1-2 undergraduates every summer and was the primary adviser for both Master's and PhD graduate dissertations. My students at UAB included Dr. Amanda Cook, Dr. Douglas White, and Dr. Christina Richey.

Other Professional Information


For a complete listing of my publications and presentations, see the results of a Harvard ADS Query for the author name "Gerakines".

Also see my Publons profile.

Publications


Refereed

Yocum, K. M., O. H. Wilkins, J. C. Bardwell, S. N. Milam, and P. A. Gerakines. 2023. Gas-phase Ortho-to-para Ratio of Formaldehyde Formed at Low Temperatures in Laboratory Ices The Astrophysical Journal Letters 958 (2): L41 [10.3847/2041-8213/ad0bee]

Hudson, R. L., and P. A. Gerakines. 2023. Infrared Spectra and Vapor Pressures of Crystalline C2N2, with Comparisons to Crystalline HCN The Planetary Science Journal 4 (11): 205 [10.3847/psj/ad0040]

Hudson, R. L., P. A. Gerakines, and Y. Yarnall. 2023. Infrared spectra and optical constants of astronomical ices: V. cyclopropane and ethylene oxide Icarus 396 115499 [10.1016/j.icarus.2023.115499]

Gerakines, P. A., C. K. Materese, and R. L. Hudson. 2023. Carbon monoxide ices – a semicentennial review and update for crystalline CO along with the first IR spectrum and band strength for amorphous CO Monthly Notices of the Royal Astronomical Society 522 (2): 3145-3162 [10.1093/mnras/stad1164]

Hudson, R. L., and P. A. Gerakines. 2023. Influences on Infrared Spectra of Benzene Ices for Titan, Comets, and Beyond: Annealings, Artifacts, and Isosbestic Points The Planetary Science Journal 4 (3): 55 [10.3847/psj/acc337]

Aslam, S., D. Glavin, G. Quilligan, et al. N. Gorius, P. A. Gerakines (he/him), J. Kolasinski, D. Tran, and T. Purser. 2022. Compact Non-Dispersive Infrared Gas Analyzer U.S. Patent 11,391,672. Washington DC: U.S. Patent and Trademark Office July 19th 2022

Hudson, R. L., Y. Yarnall, and P. A. Gerakines (he/him). 2022. Benzene Vapor Pressures at Titan Temperatures: First Microbalance Results The Planetary Science Journal 3 (5): 120 [10.3847/PSJ/ac67a5]

Hudson, R. L., Y. Yarnall, and P. A. Gerakines. 2022. Infrared Spectral Intensities of Amine Ices, Precursors to Amino Acids Astrobiology 22 (4): 452-461 [10.1089/ast.2021.0138]

Gerakines, P. A., D. Qasim, S. Frail, and R. L. Hudson. 2022. Radiolytic Destruction of Uracil in Interstellar and Solar System Ices Astrobiology 22 (3): 233-241 [10.1089/ast.2021.0053]

Hudson, R. L., P. A. Gerakines, and Y. Yarnall. 2022. Ammonia Ices Revisited: New IR Intensities and Optical Constants for Solid NH3 The Astrophysical Journal 925 (2): 156 [10.3847/1538-4357/ac3e74]

Gerakines, P. A., Y. Y. Yarnall, and R. L. Hudson. 2022. Direct measurements of infrared intensities of HCN and H2O + HCN ices for laboratory and observational astrochemistry Monthly Notices of the Royal Astronomical Society 509 (3): 3515-3522 [10.1093/mnras/stab2992]

Tran, D., N. Gorius, G. T. Quilligan, et al. Q. Gong, J. R. Kolasinski, T. C. Purser, A. Siguelnitzky, J. E. Parker, D. C. Wegel, D. P. Glavin, P. A. Gerakines, S. Aslam, and G. Nehmetallah. 2022. Gas Analyzer for Monitoring H2O and CO2 Partial Pressures in Space Instrumentation IEEE Sensors Journal 22 (1): 12576-12587 [10.1109/JSEN.2022.3177079]

Yocum, K. M., S. N. Milam, P. A. Gerakines, and S. L. Widicus Weaver. 2021. Sublimation of Laboratory Ices Millimeter/Submillimeter Experiment (SubLIME): Structure-specific Identifications of Products from UV-photolyzed Methanol Ice The Astrophysical Journal 913 (1): 61 [10.3847/1538-4357/abf14e]

Mullikin, E., H. Anderson, N. O’Hern, et al. M. Farrah, C. R. Arumainayagam, E. F. van Dishoeck, P. A. Gerakines, A. I. Vasyunin, L. Majumdar, P. Caselli, and C. N. Shingledecker. 2021. A New Method for Simulating Photoprocesses in Astrochemical Models The Astrophysical Journal 910 (1): 72 [10.3847/1538-4357/abd778]

Materese, C. K., P. A. Gerakines, and R. L. Hudson. 2021. Laboratory Studies of Astronomical Ices: Reaction Chemistry and Spectroscopy Accounts of Chemical Research 54 (2): 280-290 [10.1021/acs.accounts.0c00637]

Hudson, R. L., P. A. Gerakines, Y. Y. Yarnall, and R. T. Coones. 2021. Infrared spectra and optical constants of astronomical ices: III. Propane, propylene, and propyne Icarus 354 114033 [10.1016/j.icarus.2020.114033]

Gerakines, P. A., and R. L. Hudson. 2020. A Modified Algorithm and Open-source Computational Package for the Determination of Infrared Optical Constants Relevant to Astrophysics The Astrophysical Journal 901 (1): 52 [10.3847/1538-4357/abad39]

Materese, C. K., P. A. Gerakines, and R. L. Hudson. 2020. The Radiation Stability of Thymine in Solid H2O Astrobiology 20 (10): 956-963 [10.1089/ast.2019.2199]

Yarnall, Y. Y., P. A. Gerakines, and R. L. Hudson. 2020. Propanal, an interstellar aldehyde - first infrared band strengths and other properties of the amorphous and crystalline forms Monthly Notices of the Royal Astronomical Society 494 (4): 4606–4615 [10.1093/mnras/staa1028]

Hudson, R. L., M. J. Loeffler, R. F. Ferrante, P. A. Gerakines, and F. M. Coleman. 2020. Testing Densities and Refractive Indices of Extraterrestrial Ice Components Using Molecular Structures—Organic Compounds and Molar Refractions The Astrophysical Journal 891 (1): 22 [10.3847/1538-4357/ab6efa]

Yocum, K. M., H. H. Smith, E. W. Todd, et al. L. Mora, P. A. Gerakines, S. N. Milam, and S. L. Widicus Weaver. 2019. Millimeter/Submillimeter Spectroscopic Detection of Desorbed Ices: A New Technique in Laboratory Astrochemistry The Journal of Physical Chemistry A 123 (40): 8702-8708 [10.1021/acs.jpca.9b04587]

Hudson, R. L., and P. A. Gerakines. 2019. Molecular identifications in experiments with astronomical ice analogues: new data, old strategies, and the N2 + acetone system Monthly Notices of the Royal Astronomical Society 485 (1): 861-871 [10.1093/mnras/stz254]

Hudson, R. L., and P. A. Gerakines. 2019. Propynal, an interstellar molecule with an exceptionally strong C≡C infrared band – laboratory infrared data and applications Monthly Notices of the Royal Astronomical Society 482 (3): 4009-4017 [10.1093/mnras/sty2821]

Hudson, R. L., and P. A. Gerakines. 2018. Infrared Spectra and Interstellar Sulfur: New Laboratory Results for H<sub>2</sub>S and Four Malodorous Thiol Ices The Astrophysical Journal 867 (2): 138 [10.3847/1538-4357/aae52a]

Hudson, R. L., P. A. Gerakines, and R. F. Ferrante. 2018. IR spectra and properties of solid acetone, an interstellar and cometary molecule Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 193 33-39 [10.1016/j.saa.2017.11.055]

Hudson, R. L., M. J. Loeffler, and P. A. Gerakines. 2017. Infrared spectra and band strengths of amorphous and crystalline N<sub>2</sub>O The Journal of Chemical Physics 146 (2): 024304 [10.1063/1.4973548]

Loeffler, M. J., M. H. Moore, and P. A. Gerakines. 2016. The Effects of Experimental Conditions on the Refractive Index and Density of Low-Temperature Ices: Solid Carbon Dioxide The Astrophysical Journal 827 (2): 98 [10.3847/0004-637x/827/2/98]

Gerakines, P. A., and R. L. Hudson. 2015. First infrared band strengths for amorphous CO2, an overlooked component of interstellar ices The Astrophysical Journal Letters 808 (2): L40 [10.1088/2041-8205/808/2/L40]

Boogert, A. C., P. A. Gerakines, and D. C. Whittet. 2015. Observations of the icy universe Annual Review of Astronomy & Astrophysics 53 541-581 [10.1146/annurev-astro-082214-122348]

Smith, K. E., P. A. Gerakines, and M. P. Callahan. 2015. Metabolic precursors in astrophysical ice analogs: implications for meteorites and comets Chemical Communications 51 (59): 11787-11790 [10.1039/C5CC03272E]

Gerakines, P. A., and R. L. Hudson. 2015. Infrared spectra and optical constants of elusive amorphous methane Astrophysical Journal Letters 805 (2): L20 [10.1088/2041-8205/805/2/L20]

Hudson, R. L., P. A. Gerakines, and M. J. Loeffler. 2015. Activation of weak IR fundamentals of two species of astrochemical interest in the Td point group – the importance of amorphous ices Physical Chemistry Chemical Physics 17 (19): 12545-12552 [10.1039/C5CP00975H]

Gerakines, P. A., and R. L. Hudson. 2015. The radiation stability of glycine in solid CO2 – In situ laboratory measurements with applications to Mars Icarus 252 466-472 [10.1016/j.icarus.2015.02.008]

Hudson, R. L., P. A. Gerakines, and M. H. Moore. 2014. Infrared Spectra and Optical Constants of Astronomical Ices: II. Ethane and Ethylene Icarus 243 147-148 [10.1016/j.icarus.2014.09.001]

Smith, K. E., M. P. Callahan, P. A. Gerakines, J. P. Dworkin, and C. H. House. 2014. Investigation of pyridine carboxylic acids in CM2 carbonaceous chondrites: Potential precursor molecules for ancient coenzymes Geochimica et Cosmochimica Acta 136 1-12 [10.1016/j.gca.2014.04.001]

Callahan, M. P., P. A. Gerakines, M. G. Martin, Z. Peeters, and R. L. Hudson. 2013. Irradiated benzene ice provides clues to meteoritic organic chemistry Icarus 226 (2): 1201-1209 [10.1016/j.icarus.2013.07.033]

Gerakines, P. A., and R. L. Hudson. 2013. Glycine's Radiolytic Destruction in Ices: First in situ Laboratory Measurements for Mars Astrobiology 13 647-655 [10.1089/ast.2012.0943]

Richey, C. R., and P. A. Gerakines. 2012. Near-infrared band strengths of molecules diluted in N<sub>2</sub> and H<sub>2</sub>O ice mixtures relevant to interstellar and planetary ices The Astrophysical Journal 759 74-86 [10.1088/0004-637X/759/1/74]

Gerakines, P. A., R. L. Hudson, M. H. Moore, and J.-L. Bell. 2012. In-situ Measurements of the Radiation Stability of Amino Acids at 15 - 140 K Icarus 220 647-659 [10.1016/j.icarus.2012.06.001]

Cook, A. M., D. C. Whittet, S. S. Shenoy, et al. P. A. Gerakines, D. W. White, and J. E. Chiar. 2011. The Thermal Evolution of Ices in the Environments of Newly Formed Stars: The CO<sub>2</sub> Diagnostic The Astrophysical Journal 730 (2): 124-138 [10.1088/0004-637X/730/2/124]

White, D., P. A. Gerakines, D. Whittet, and A. Cook. 2009. Laboratory Spectra of the CO<sub>2</sub> Bending-Mode Feature in Interstellar Ice Analogs Subject to Thermal Processing Astrophysical Journal Supplement Series 180 182-191 [10.1088/0067-0049/180/1/182]

Agresti, D. G., and P. A. Gerakines. 2009. Simultaneous Fitting of Mars Moessbauer Data Hyperfine Interactions 188 113-120 [10.1007/s10751-008-9896-1]

Whittet, D. C., A. M. Cook, S. S. Shenoy, et al. J. E. Chiar, Y. J. Pendleton, and P. A. Gerakines. 2009. The Nature of Carbon Dioxide Bearing Ices in Quiescent Molecular Clouds The Astrophysical Journal 695 94-100 [10.1088/0004-637X/695/1/94]

Sonnentrucker, P., D. A. Neufeld, P. A. Gerakines, et al. E. A. Bergin, G. J. Melnick, W. J. Forrest, J. L. Pipher, and D. C. Whittet. 2008. Fully Sampled Maps of Ices and Silicates in Front of Cepheus A East with Spitzer The Astrophysical Journal 672 361-370 [10.1086/523790]

Whittet, D. C., S. S. Shenoy, E. A. Bergin, et al. J. E. Chiar, P. A. Gerakines, E. L. Gibb, G. J. Melnick, and D. A. Neufeld. 2007. The abundance of carbon dioxide ice in the quiescent intracloud medium The Astrophysical Journal 655 (1): 332-341 [10.1086/509772]

Abbas, M. M., D. Tankosic, P. D. Craven, et al. J. F. Spann, A. LeClair, E. A. West, J. C. Weingartner, A. G. Tielens, J. A. Nuth, R. P. Camata, and P. A. Gerakines. 2006. Photoelectric Emission Measurements on the Analogs of Individual Cosmic Dust Grains The Astrophysical Journal 645 (1): 324-336 [10.1086/504281]

Bergin, E. A., G. J. Melnick, P. A. Gerakines, D. A. Neufeld, and D. C. Whittet. 2005. Spitzer Observations of CO<sub>2</sub> Ice Towards Field Stars in the Taurus Molecular Cloud The Astrophysical Journal 627 (1): L33-L36 [10.1086/431932]

Gerakines, P. A., J. J. Bray, A. Davis, and C. R. Richey. 2005. The Strengths of Near-Infrared Absorption Features Relevant to Interstellar and Planetary ices The Astrophysical Journal 620 (2): 1140-1150 [10.1086/427166]

Gerakines, P. A., M. H. Moore, and R. L. Hudson. 2004. Ultraviolet Photolysis and Proton Irradiation of Astrophysical Ice Analogs Containing Hydrogen Cyanide Icarus 170 (1): 202-213 [10.1016/j.icarus.2004.02.005]

Nummelin, A., D. C. Whittet, E. L. Gibb, P. A. Gerakines, and J. E. Chiar. 2001. Solid Carbon Dioxide in Regions of Low-Mass Star Formation The Astrophysical Journal 558 (1): 185-193 [10.1086/322480]

Hudson, R. L., M. H. Moore, and P. A. Gerakines. 2001. The Formation of Cyanate Ion (OCN<sup>-</sup>) in Interstellar Ice Analogs The Astrophysical Journal 550 (2): 1140-1150 [10.1086/319799]

Moore, M. H., R. L. Hudson, and P. A. Gerakines. 2001. Mid- and Far-Infrared Spectroscopic Studies of the Influence of Temperature, Ultraviolet Photolysis, and Ion Irradiation on Cosmic-Type Ices Spectrochimica Acta A 57 (4): 843-858 [10.1016/S1386-1425(00)00448-0]

Whittet, D. C., P. A. Gerakines, J. H. Hough, and S. S. Shenoy. 2001. Interstellar Extinction and Polarization in the Taurus Dark Clouds: The Optical Properties of Dust near the Diffuse/Dense Cloud Interface The Astrophysical Journal 547 (2): 872-884 [10.1086/318421]

Gerakines, P. A., M. H. Moore, and R. L. Hudson. 2001. Energetic Processing of Laboratory Ice Analogs: UV Photolysis vs. Ion Bombardment Journal of Geophysical Research: Planets 106 (E12): 33381-33386 [10.1029/2000JE001320]

Wdowiak, T. J., P. A. Gerakines, D. G. Agresti, and S. J. Clemett. 2001. Technology Considerations Relevant to an Exobiology Surface-Science Approach for Europa Astrobiology 1 467-476

Gerakines, P. A., and M. H. Moore. 2001. Carbon Suboxide in Astrophysical Ice Analogs Icarus 154 372-380

Gibb, E. L., D. C. Whittet, W. A. Schutte, et al. A. C. Boogert, J. E. Chiar, P. Ehrenfreund, P. A. Gerakines, J. V. Keane, A. G. Tielens, E. F. van Dishoeck, and O. Kerkhof. 2000. An Inventory of Interstellar Ices toward the Embedded Protostar W33A The Astrophysical Journal 536 (1): 347-356 [10.1086/308940]

Gerakines, P. A., M. H. Moore, and R. L. Hudson. 2000. Carbonic Acid Production in H<sub>2</sub>O:CO<sub>2</sub> ices UV Photolysis vs Proton Bombardment Astronomy & Astrophysics 357 793-800

Boogert, A. C., P. Ehrenfreund, P. A. Gerakines, et al. A. G. Tielens, D. C. Whittet, W. A. Schutte, E. F. van Dishoeck, T. de Graauw, L. Decin, and T. Prusti. 2000. ISO-SWS Observations of Interstellar Solid <sup>13</sup>CO<sub>2</sub>: Heated Ice and the Galactic <sup>12</sup>C/<sup>13</sup>C Abundance Ratio Astronomy & Astrophysics 353 (1): 349-362 [10.48550/arXiv.astro-ph/9909477]

Gerakines, P. A., D. C. Whittet, P. Ehrenfreund, et al. A. C. Boogert, A. G. Tielens, W. A. Schutte, J. E. Chiar, E. F. van Dishoeck, T. Prusti, F. P. Helmich, and T. de Graauw. 1999. Observations of Solid Carbon Dioxide in Molecular Clouds with the Infrared Space Observatory The Astrophysical Journal 522 (1): 357-377 [10.1086/307611]

Schutte, W. A., A. C. Boogert, A. G. Tielens, et al. D. C. Whittet, P. A. Gerakines, J. E. Chiar, P. Ehrenfreund, J. M. Greenberg, E. F. van Dishoeck, and T. de Graauw. 1999. Weak Ice Absorption Features in the Spectrum of the Obscured Young Stellar Object W33 A Astronomy & Astrophysics 343 966-976

Vandenbussche, B., P. Enhrenfreund, A. C. Boogert, et al. E. F. van Dishoeck, W. A. Schutte, P. A. Gerakines, J. E. Chiar, A. G. Tielens, J. V. Keane, D. C. Whittet, M. Breitfellner, and M. Burgdorf. 1999. Constraints on the Abundance of Solid O<sub>2</sub> in Dense Clouds from ISO-SWS and Ground-Based Observations Astronomy & Astrophysics 346 L57-L60

Ehrenfreund, P., O. Kerkhof, W. A. Schutte, et al. A. C. Boogert, P. A. Gerakines, E. Dartois, L. dHendecourt, A. G. Tielens, E. F. van Dishoeck, and D. C. Whittet. 1999. Laboratory Studies of Thermally Processed H<sub>2</sub>O-CH<sub>3</sub>OH-CO<sub>2</sub> Ice Mixtures and their Astrophysical Implications Astronomy & Astrophysics 350 240?253

Chiar, J. E., P. A. Gerakines, D. C. Whittet, et al. Y. J. Pendleton, A. G. Tielens, A. J. Adamson, and A. C. Boogert. 1998. Processing of Icy Mantles in Protostellar Envelopes The Astrophysical Journal 498 (2): 716-727 [10.1086/305569]

Whittet, D. C., P. A. Gerakines, A. G. Tielens, et al. A. J. Adamson, A. C. Boogert, J. E. Chiar, T. de Graauw, P. Ehrenfreund, T. Prusti, W. A. Schutte, B. Vandenbussche, and E. F. van Dishoeck. 1998. Detection of Abundant CO<sub>2</sub> Ice in the Quiescent Dark Cloud Medium toward Elias 16 The Astrophysical Journal 498 L159-L163

Whittet, D. C., A. C. Boogert, P. A. Gerakines, et al. W. A. Schutte, A. G. Tielens, T. de Graauw, T. Prusti, E. F. van Dishoeck, P. R. Wesselius, and C. M. Wright. 1997. Infrared Spectroscopy of Dust in the Diffuse Interstellar Medium toward Cygnus OB2 No 12 The Astrophysical Journal 490 (2): 729-734 [10.1086/304914]

Whittet, D. C., T. Prusti, G. A. Franco, et al. P. A. Gerakines, D. Kilkenny, K. A. Larson, and P. R. Wesselius. 1997. On the Distance to the Chamaeleon I and II Associations Astronomy & Astrophysics 327 1194-1205

Ehrenfreund, P., A. C. Boogert, P. A. Gerakines, A. G. Tielens, and E. F. van Dishoeck. 1997. Infrared Spectroscopy of Interstellar Apolar Ice Analogs Astronomy & Astrophysics 328 649-669

Schutte, W. A., P. A. Gerakines, T. R. Geballe, E. F. van Dishoeck, and J. M. Greenberg. 1996. Discovery of Solid Formaldehyde toward the Protostar GL 2136: Observations and Laboratory Simulation Astronomy & Astrophysics 309 633-647

Ehrenfreund, P., P. A. Gerakines, W. A. Schutte, M. C. van Hemert, and E. F. van Dsihoeck. 1996. Infrared Properties of Isolated Water Ice Astronomy & Astrophysics 312 263-274

Gerakines, P. A., W. A. Schutte, and P. Ehrenfreund. 1996. Ultraviolet Processing of Interstellar Ice Analogs: Pure Ices Astronomy & Astrophysics 312 289-305

Ehrenfreund, P., A. C. Boogert, P. A. Gerakines, et al. D. J. Jansen, W. A. Schutte, A. G. Tielens, and E. F. van Dishoeck. 1996. A Laboratory Database of Solid CO and CO<sub>2</sub> for ISO Astronomy & Astrophysics 315 L341-L344

de Graauw, T., D. C. Whittet, P. A. Gerakines, et al. O. H. Bauer, D. A. Beintema, A. C. Boogert, D. R. Boxhoorn, J. E. Chiar, P. Ehrenfreund, H. Feuchtgruber, F. P. Helmich, A. M. Heras, R. Huygen, D. J. Kester, D. Kunze, P. W. Morris, T. Prusti, P. R. Roelfsema, A. Salama, S. G. Schaeidt, W. A. Schutte, H. W. Spoon, A. G. Tielens, E. A. Valentijn, B. Vandenbussche, E. F. van Dishoeck, P. R. Wesselius, E. Wieprecht, and C. M. Wright. 1996. SWS Observations of Solid CO<sub>2</sub> in Molecular Clouds Astronomy & Astrophysics 315 L345-L348

van Dishoeck, E. F., F. P. Helmich, T. de Graauw, et al. J. H. Black, A. C. Boogert, P. Ehrenfreund, P. A. Gerakines, J. H. Lacy, T. J. Millar, W. A. Schutte, A. G. Tielens, D. C. Whittet, D. R. Boxhoorn, D. J. Kester, K. Leech, P. R. Roelfsema, A. Salama, and B. Vandenhussche. 1996. A Search for Interstellar Gas-phase CO<sub>2</sub> - Gas:Solid-State Abundance Ratios Astronomy & Astrophysics 315 L349-L352

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