Robert W. O'Connell, J. D. Hamilton Professor

Email: rwo@virginia.edu Phone: (434) 924-7494 Fax: (434) 924-3104 Office: 251-B Astronomy Building Address: Department of Astronomy University of Virginia PO Box 400325 Charlottesville, VA 22904-4325 USA

Brief Curriculum Vitae:

• Birthplace: San Francisco, 1943.
• AB, Astronomy, University of California, Berkeley, 1964.
• Ph.D., Astronomy & Physics, California Institute of Technology, 1970.
• Postdoctoral Fellow, Lick Observatory, U.C. Santa Cruz, 1969-71.
• Faculty Member, Department of Astronomy, University of Virginia, 1971-- .
• Department Chair, 1979-85, 1988-89, 1995-99.
• John Downman Hamilton Professor, 1996-- .
• Chair, Scientific Oversight Committee, Hubble Space Telescope Wide Field Camera 3, 1998-- .
• Vice President, American Astronomical Society, 2006--.

Research Interests: Evolution of Galaxies Stellar Populations Cooling Flows in Clusters of Galaxies Super Star Clusters and Starburst Galaxies Hot Stars in Globular Clusters Space Astronomy: UV, X-ray, & IR

Courses Taught:

• Astronomy 121: Introduction to the Sky & Solar System
• Astronomy 130: Introduction to Astronomical Observations
• Astronomy 511: Observational Techniques
• Astronomy 539: Stellar Populations
• Astronomy 836: Current Astronomical Topics: "Top-10 Lists"

Hubble Space Telescope Wide Field Camera 3:

Background: Main Web Site/Information Science White Paper Science Documents Status: October 2004: WFC3 successfully completed initial thermal/vacuum testing at Goddard Space Flight Center January 2006: final filter procurement & installation; optimized IR detectors in fabrication & test October 2006: SM-4 approved June-October 2007: primary thermal/vacuum test at Goddard SFC using flight-spare detectors. Flight detectors in test/assembly. [Scheduled] January-Februrary 2008: final thermal/vacuum test. [Scheduled] SM-4 launch: 8 August 2008 Status of Servicing Mission 4: The servicing mission was approved by Administrator Griffin in October 2006, with a tentative date of September 2008. During the mission, WFC3 and the Cosmic Origins Spectrograph will be installed as the final complement of new science instruments on Hubble. ACS and STIS will be repaired. Other essential hardware, including batteries and gyros, will also be installed so that HST can continue operations will a full instrument complement for another 5 years. Letter to HST/JWST Transition Panel (July 2003) Report on HST/JWST Transition and Servicing Mission 4 (Aug 2003) SOC Resolutions on Future of WFC3 (Feb 2004) AURA Forum on HST Servicing Washington Post article on robot servicing (Nov 2004) National Academy Assessment of Servicing Options (Jan 2005) Congressional Hearing on Hubble Options (Feb 2005, AIP FYI) Bahcall, McKee, Taylor on Future of Hubble (March 2005, L.A. Times) Hubble Repair Effort: Thrills & Chills (Bruce Balick site) SM4 Decision Unsupported by Risk Analysis (March 2005, R. Zimmerman) Hubble Celebrates 15th Anniversary (April 2005, NASA Press Release) Shuttle Rescue Mission for HST Gears Up (May 2005, Nature) Administrator Griffin Remarks to the American Astronomical Society, January 2006 Hubble Repair Mission Approved, October 2006 Hubble Saved (space.com)

Cutaway diagram of WFC3 showing the optical paths for the dual UV-visible and IR cameras (Click for enlargement) Astronauts practice installing WFC3 into HST mock-up in Neutral Buoyancy Lab (Click for enlargement)

Click here for images from the Astro/UIT missions.

The Ultraviolet Imaging Telescope (UIT), one of the three ultraviolet telescopes of the Astro Observatory, flew on Space Shuttle missions in December 1990 and March 1995. It was a 38-cm telescope carrying two ultraviolet cameras with 40 arc-minute diameter fields of view (150 times larger than the field of the Hubble Space Telescope). The cameras employed image intensifiers with very strong long-wavelength rejection to provide pure UV images. Resolution for point sources was typically 2.7 arc-seconds FWHM. During the two Astro missions, UIT returned a total of 1570 data frames of 250 different astronomical targets. UIT was designed and built at Goddard Space Flight Center by a group headed by Ted Stecher.

Click on the thumbnail at right to see a sample UIT data frame (328K) from the Astro-1 mission. This is a far-ultraviolet (1500 Angstroms) image of the globular cluster Omega Centauri , one of the most massive in our Galaxy. Over 1900 stars are visible in the UIT image, most of them hotter than 10,000 degrees. These stars are over 12 billion years old. They have exhausted hydrogen in their cores and are now burning helium, just prior to collapsing toward the terminal white dwarf phase of evolution. Many cooler stars also reside in this cluster, but they are suppressed in the image because they emit very little UV light. Thus, the hot stars can be studied in isolation in these UV images. The field of view includes the entire cluster. The exposure was five minutes long. It was taken in full sunlight; but because the atmosphere above Shuttle altitude is so thin, and the sun is so dark in the far-ultraviolet, there is very little sky background on the frame.

A sample UIT data frame (237K) from the Astro-2 mission can be viewed by clicking on the thumbnail at the right. This shows the face-on spiral galaxy Messier 101 in the far-ultraviolet. Again, the bright regions contain stars hotter than 10000 degrees, but in this case, they are mostly very young, massive objects with ages less than 10 million years. Exposure time was 22 minutes at 1500 Angstroms. The field of view has been clipped to 29 arc-minutes across. UV images like this are important for predicting the appearance of very distant normal galaxies, whose restframe UV is redshifted to longer (optical/IR) wavelengths. Click here to see a simulation of a high redshift galaxy based on this image.

A general introduction to the Astro missions together with more instrument, flight, and science images and links to videos can be found here. A technical description of UIT may be found in Astrophysical Journal, vol. 395, page L1, 1992 and in Publ. Astron. Soc. Pacific, vol. 109, page 584, 1997. UIT data can be downloaded from the STScI Multimission Archive. A partial list of UIT publications may be found here.

A lecture (advanced undergraduate/graduate) on scientific goals, instrumental & technical considerations, and other missions in UV astronomy can be found here.

Alumni of the UVA/UIT group: Nicholas Collins, Brian McNamara, Michael Fanelli, Gregory Hennessy, Melanie Swain, Ben Dorman, Wesley Colley, Christoper Mullis, Jonathan Whitney, R. Brian Grant, Noella D'Cruz, Pamela Marcum, Raymond Ohl, Ronak Shah, Chris Palma, George Becker, Rolling Liu, Richard de Grijs.

Data analysis software for the UIT project was written mainly in IDL (the Interactive Data Language). Much of this is of general interest for analysis of astronomical and other data and is publicly available. Without a doubt, IDL is the best interactive language available for computer-literate physical scientists. See my Guide to IDL for Astronomers, the IDL Astronomy User's Library, and the UVa IDL Resources Page for more information and lists of useful IDL links.

Some Recent Publications

The Red Envelope and the Age of the Universe, O'Connell, R. W., in Towards Understanding Galaxies at Large Redshift, eds. R. Kron and A. Renzini (Dordrecht: Reidel), p.177, 1988. Preprint (*ps.gz).

Star Formation in Cooling Flows in Clusters of Galaxies, McNamara, B. R., and O'Connell, R. W., AJ, 98, 2018, 1989.

Simulated Optical Images of Galaxies at z ~ 1 Using UV Images of Nearby Galaxies, Bohlin, R. C., Cornett, R. H., Hill, J. K., Hill, R. S., O'Connell, R. W., Neff, S. G., Smith, A. M., and Stecher, T. P., ApJ, 368, 12, 1991.

Spectral Synthesis in the Ultraviolet. IV: A Library of Standard Stellar Groups, Fanelli, M. N., O'Connell, R. W., Burstein, D., and Wu, C.-C., ApJSupp, 82, 197, 1992. Data Set (ADC format).

Color Gradients in Cooling Flows in Clusters of Galaxies, McNamara, B. R., and O'Connell, R. W., ApJ, 393, 579, 1992.

Ultraviolet Imaging of Old Populations in Nearby Galaxies,O'Connell, R. W., Bohlin, R. C., Collins, N. R., Cornett, R. H., Hill, J. K., Hill, R. S., Landsman, W. B., Roberts, M. S., Smith, A. M., and Stecher, T. P., ApJLett, 395, L45, 1992.

X-Ray and Optical Emission Line Filaments in the Cooling Flow Cluster 2A0335+096, Sarazin, C. L., O'Connell, R. W., and McNamara, B. R., ApJLett, 397, L31, 1992.

Far-Infrared Emission from the Intracluster Medium, Wise, M. W., O'Connell, R. W., Bregman, J. N., and Roberts, M. S., ApJ, 405, 94, 1993.

The Nuclear Disk of NGC 4261: Images and Spectroscopic Data, Jaffe, W., Ford, H., Ferrarese, L., van den Bosch, F., and O'Connell, R. W., Nature, 364, 213, 1993. Image.

Hubble Space Telescope Imaging of Super Star Clusters in NGC 1569 and NGC 1705, O'Connell, R. W., Gallagher, J. S., and Hunter, D. A., ApJ, 433, 65, 1994. 1569 image. 1569 cluster A image.

The Ages of Elliptical Galaxies O'Connell, R. W., in Nuclei of Normal Galaxies: Lessons from the Galactic Center, eds. R. Genzel and A. I. Harris (Dordrecht: Kluwer), 255, 1994. Preprint (*.ps.gz). Preprint (*.pdf).

Far Ultraviolet Photometry of the Globular Cluster Omega Centauri. Whitney, J. H., O'Connell, R. W., Rood, R. T., Dorman, B., Landsman, W. B., Bohlin, R. C., Cheng, K.-P., Hintzen, P., Roberts, M. S., Smith, A. M., Smith, E. P., and Stecher, T. P., AJ, 108, 1350, 1994. Image.

Ultraviolet Radiation from Evolved Stellar Populations II. The Ultraviolet Upturn Phenomenon in Elliptical Galaxies, Dorman, B., O'Connell, R. W., and Rood, R. T., ApJ, 442, 105, 1995.

Hubble Space Telescope Imaging of Super Star Clusters in M82, O'Connell, R. W., Gallagher, J. S., Hunter, D. A., and Colley, W. N., ApJLett, 446, L1, 1995. Image.

An Overview of Spectral Synthesis of Stellar Populations, O'Connell, R. W., in From Stars to Galaxies: The Impact of Stellar Physics on Galaxy Evolution, eds. C. Leitherer, U. Fritze-von Alvensleben, and J. Huchra, p. 3, 1996. Preprint (*.ps.gz).

The Origin of Extreme Horizontal Branch Stars D'Cruz, N. L., Dorman, B., Rood, R. T., and O'Connell, R. W., ApJ, 466, 359, 1996.

The Star Formation History of Low Redshift Spiral Galaxies, O'Connell, R. W., in Star Formation, Near and Far, eds. S. S. Holt and L. G. Mundy (AIP Press), p. 491, 1997. Preprint (*.ps.gz).

The Ultraviolet Morphology of Galaxies,, O'Connell, R. W.,in The Ultraviolet Universe at Low and High Redshift, ed. W. H. Waller (AIP Press), p. 11, 1997. Preprint (*.ps.gz).

Integrated UV Spectra and Line Indices of M31 Globular Clusters and the Cores of Elliptical Galaxies, Ponder, J. M., Burstein, D., O'Connell, R. W., Rose, J., Frogel, J. A., Wu, C.-C., Crenshaw, D. M., Rieke, M., and Tripicco, M., AJ, 116, 2297, 1998.

Far-Ultraviolet Color Gradients in Early-Type Galaxies, Ohl, R. G., O'Connell, R. W., Bohlin, R. C., Collins, N. R., Dorman, B., Fanelli, M. N., Neff, S. G., Roberts, M. S., Smith, A. M., and Stecher, T. P., ApJLett, 505, L11, 1998.

Far-Ultraviolet Radiation From Elliptical Galaxies, O'Connell, R. W., Ann. Rev. Astr. Ap., 37, 603, 1999.

Stellar Populations at Large Redshifts: Updated Review, O'Connell, R. W. in Stellar Populations (IAU Symposium No. 164), eds. P. van der Kruit and G. Gilmore, Ap&SS, 267, 329, 1999. Preprint.

Energy Distributions and the Formation Times of Spheroidal Populations, O'Connell, R. W., in Building the Galaxies: From the Primordial Universe to the Present (XIXth Moriond Astrophysics Conference), eds. F. Hammer, T. X. Thuan, V. Cayatte, B. Guiderdoni, and J. T. T. Van (Paris: Editions Frontieres), p. 3, 2000. Preprint. Preprint (*.pdf).

HST Observations of New Horizontal Branch Structures in the Globular Cluster Omega Centauri, D'Cruz, N. L., O'Connell, R. W., Rood, R. T., Whitney, J. H., Dorman, B., Landsman, W. B., Stecher, T. P., and Bohlin, R. C., ApJ, 530, 352, 2000.

Supernova Remnants in the Fossil Starburst in M82,, de Grijs, R., O'Connell, R. W., Becker, G. D., Chevalier, R. A., and Gallagher, J. S., AJ, 119, 681, 2000.

Comparing Galaxy Morphology at Ultraviolet and Optical Wavelengths, Kuchinski, L. E., Freedman, W. L., Madore, B. F., Trewhella, M., Bohlin, R. C., Cornett, R. H., Fanelli, M. N., Marcum, P. M., Neff, S. G., O'Connell, R. W., Roberts, M. S., Smith, A. M., Stecher, T. P., and Waller, W. H., ApJ Suppl, 131, 441, 2000.

An Ultraviolet/Optical Atlas of Bright Galaxies, Marcum, P. M., O'Connell, R. W., Fanelli, M. N., Bohlin, R. C., Cheng, K.-P., Collins, N. R., Cornett, R. H., Freedman, W. L., Hennessy, G. S., Hintzen, P., Hollis, J. E., Kuchinski, L. E., Landsman, W. B., Madore, B., Ohl, R. G., Neff, S. G., Palma, C., Parise, R. A., Roberts, M. S., Smith, E. P., Talbert, F., Waller, W. H., and Stecher, T. P., ApJ Suppl, 132, 129, 2001.

The Fossil Starburst in M82, de Grijs, R., O'Connell, R. W., and Gallagher, J. S., III, AJ, 121, 768, 2001. HST optical/IR comparison images of M82: de Grijs & O'Connell or STScI press release.

Super Star Clusters in M82, O'Connell, R. W., in Extragalactic Star Clusters (IAU Symposium No. 207), eds. E. K. Grebel, D. Geisler, and D. Minniti (San Francisco: ASP), p. 383, 2002. Preprint. High resolution figures available here.

Age and Abundance Discrimination in Old Stellar Populations Using Mid-Ultraviolet Colors, Dorman, B., O'Connell, R. W., and Rood, R. T., ApJ, 591, 878, 2003.

Conference Summary: Ten Years of Super Star Cluster Research, O'Connell, R. W., in The Formation and Evolution of Massive Young Star Clusters, eds. H. Lamers, A. Nota and L. Smith (San Francisco: ASP), p. 551, 2004. Preprint.

Conference Summary: Starbursts and Galaxy Evolution, O'Connell, R. W., in Starbursts: From 30 Dor to Lyman Break Galaxies, eds. R. de Grijs & R. M. Gonzalez Delgado (Dordrecht: Kluwer), p. 333, 2005. Preprint.

Hot Populations in M87 Globular Clusters, Sohn, S. T., O'Connell, R. W., Kundu, A., Landsman, W. B., Burstein, D., Bohlin, R., Frogel, J. A., and Rose, J. A., AJ, 131, 866, 2006.

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