• The c2d Spitzer Spectroscopic Survey Of Ices Around Low-Mass Young Stellar Objects. I. H2O And The 5-8 Mu M Bands 

      Boogert, Adwin C. A.; Pontoppidan, Klaus M.; Knez, Claudia; Lahuis, Fred; Kessler-Silacci, J.; van Dishoeck, Ewine F.; Blake, Geoffrey A.; Augereau, Jean-Charles; Bisschop, S. E.; Bottinelli, Sandrine; Brooke, Tyler Y.; Brown, Justin; Crapsi, Antonio; Evans, Neal J.; Fraser, Helen J.; Geers, V.; Huard, Tracy L.; Jorgensen, Jes K.; Oberg, Karin I.; Allen, Lori E.; Harvey, Paul M.; Koerner, David W.; Mundy, Lee G.; Padgett, Deborah L.; Sargent, Anneila I.; Stapelfeldt, Karl R. (2008-05)
      To study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L similar to 0.1-10 L-circle dot) using 3-38 mu m Spitzer and ground-based ...
    • Chemical evolution of ice and gas from molecular clouds to protostars 

      Knez, Claudia (2006)
      We present observations toward stars behind molecular clouds (back ground stars) and toward massive protostars in order to study the chemical evolution in molecular clouds before and during star formation. Infrared ...
    • High-Resolution Mid-Infrared Spectroscopy Of NGC 7538 IRS 1: Probing Chemistry In A Massive Young Stellar Object 

      Knez, Claudia; Lacy, John H.; Evans, Neal J.; van Dishoeck, Ewine F.; Richter, Matthew J. (2009-05)
      We present high-resolution (R = 75,000-100,000) mid-infrared spectra of the high-mass embedded young star IRS 1 in the NGC 7538 star-forming region. Absorption lines from many rotational states of C(2)H(2), (13)C(12)CH(2), ...
    • The Properties of Massive, Dense Clumps: Mapping Surveys of HCN and CS 

      Wu, Jingwen; Evans, Neal J., II; Shirley, Yancy L.; Knez, Claudia (2010-06)
      We have mapped over 50 massive, dense clumps with four dense gas tracers: HCN J = 1-0 and 3-2; and CS J = 2-1 and 7-6 transitions. Spectral lines of optically thin H(13)CN 3-2 and C(34)S 5-4 were also obtained toward the ...
    • The Relationship Between The Optical Depth Of The 9.7 ?m Silicate Absorption Feature And Infrared Differential Extinction In Dense Clouds 

      Chiar, J. E.; Ennico, K.; Pendleton, Y. J.; Boogert, Adwin C. A.; Greene, T.; Knez, Claudia; Lada, C.; Roellig, T.; Tielens, Aggm; Werner, M.; Whittet, D. C. B. (2007-09)
      We have examined the relationship between the optical depth of the 9.7 mm silicate absorption feature (tau(9.7)) and the near-infrared color excess E(J - K-s), in the Serpens, Taurus, IC 5146, Chameleon I, Barnard 59, and ...
    • The Spitzer Survey of Interstellar Clouds in the Gould Belt. III. A Multi-Wavelength View of Corona Australis 

      Peterson, Dawn E.; Garatti, Alessio Caratti O.; Bourke, Tyler L.; Forbrich, Jan; Gutermuth, Robert A.; Jorgensen, Jes K.; Allen, Lori E.; Patten, Brian M.; Dunham, Michael M.; Harvey, Paul M.; Merin, Bruno; Chapman, Nicholas L.; Cieza, Lucas A.; Huard, Tracy L.; Knez, Claudia; Prager, Brian; Evans, Neal J., II (2011-06)
      We present Spitzer Space Telescope IRAC and MIPS observations of a 0.85 deg(2) field including the Corona Australis (CrA) star-forming region. At a distance of 130 pc, CrA is one of the closest regions known to be actively ...