Gary Joseph Ferland
2025 Bruce Medalist
Date of Birth:
Gary Ferland was born in Washington, DC, and grew up in the many places that his father's military career took the family. He earned his B.S. in 1973 and his Ph.D. in 1978 at the University of Texas at Austin, where his doctoral dissertation included spectroscopic observations of Nova V1500 Cygni. He then went to the University of Cambridge to work with Martin J. Rees on the spectra of gas falling into supermassive black holes at the cores of galaxies. While analyzing quasar spectra from the International Ultraviolet Explorer, he wrote a computer program to synthesize spectra of ionized gases under various conditions. Some 47 years and about 20 versions later, Cloudy has won many awards, including the first “Code of Honor” from Nature. It remains the most comprehensive code for astronomical spectroscopy. It has gone through several computer languages and been used in thousands of research papers. It has remained open source with frequent maintenance and expansion. It now includes molecular and atomic gases as well as plasmas. It also includes nonequilibrium gases and the entire electromagnetic spectrum, from emission and absorption lines in the radio to those in the gamma ray region. Eighteen graduate students have helped develop it and used it for their doctoral research under Ferland. He and his students and colleagues have used it to study nebulous regions in our Galaxy, such as the Orion Nebula and other photoionized clouds and novae, and conditions in quasars and other active galactic nuclei. This work has increased our knowledge of the chemical composition of the Universe and its evolution. Its creator says, "Cloudy is a starship to explore the Universe with spectroscopy."
After his highly productive two-year postdoctoral position at Cambridge, Ferland joined the faculty of the University of Kentucky. He left for Ohio State University in 1985, but returned to Kentucky in 1992, where he has remained ever since. When Donald Osterbrock was considering revising his influential graduate textbook and reference, Astrophysics of Gaseous Nebulae and Active Galactic Nuclei, he chose Ferland as his coauthor. Published in 2005, this book is still in print.
Personal Web Page
Biographical materials
Behind the Blue, University of Kentucky podcast, 2021 (transcript).
Academic genealogy
Portraits
Wikipedia, 2023
Named after him
Minor Planet #30521 Garyferland
Bibliography
Other References: Historical
Search ADS for works about Ferland
Other References: Scientific
Bernat, A.; Ferland, G.; Robbins, R. R. and 1 colleague, “SEC Vidicon Slitless [OII] Images of NGC 2440,” Bulletin of the American Astronomical Society, 5, 423 (1973).
Ferland, G. and Netzer, H., “Application of line transfer calculations to active nuclei and novae,” The Astrophysical Journal 229, 274 (1979).
Ferland, G. J., “Hydrogenic emission and recombination coefficients for a wide range of temperature and wavelength,” Publications of the Astronomical Society of the Pacific 92, 596 (1980).
Ferland, G. J. and Mushotzky, R. F., “Broad line region clouds and the absorbing material in NGC 4151,” The Astrophysical Journal 262, 564 (1982).
Ferland, G. J. and Netzer, H., “Are there any shock-heated galaxies?,” The Astrophysical Journal 264, 105 (1983).
Mushotzky, R. and Ferland, G. J., “The line continuum luminosity ratio in active galactic nuclei : on the ‘Baldwin effect’.” The Astrophysical Journal 278, 558 (1984).
Gaskell, C. M. and Ferland, G. J., “Theoretical hydrogen-line ratios for the narrow-line regions of active galactic nuclei,” Publications of the Astronomical Society of the Pacific 96, 393 (1984).
Ferland, G. J. and Osterbrock, D. E., “IUE Spectra and a Resulting Model of Seyfert 2 Galaxies,” The Astrophysical Journal 300, 658 (1986).
Mathews, William G. and Ferland, Gary J., “What Heats the Hot Phase in Active Nuclei?,” The Astrophysical Journal 323, 456 (1987).
Ferland, G. J. and Rees, M. J., “Radiative Equilibrium of High-Density Clouds, with Application to Active Galactic Nucleus Continua,” The Astrophysical Journal 332, 141 (1988).
Rees, M. J.; Netzer, Hagai; and Ferland, G. J., “Small Dense Broad-Line Regions in Active Nuclei,” The Astrophysical Journal 347, 640 (1989).
Ferland, Gary J. and Persson, S. Eric, “Implications of CA II Emission for Physical Conditions in the Broad-Line Region of Active Galactic Nuclei,” The Astrophysical Journal 347, 656 (1989).
Ferland, G. J.; Korista, K. T.; and Peterson, B. M., “Optically Thin Thermal Emission as the Origin of the Big Bump in the Spectra of Active Galactic Nuclei,” The Astrophysical Journal 363, L21 (1990).
Ferland, G. J., “Hazy, A Brief Introduction to Cloudy 80,” The Ohio State University Internal Report (1991).
Baldwin, Jack A.; Ferland, Gary J.; Martin, P. G., and 4 colleagues, “Physical Conditions in the Orion Nebula and an Assessment of Its Helium Abundance,” The Astrophysical Journal 374, 580 (1991).
Ferland, G. J.; Peterson, B. M.; Horne, K., and 2 colleagues, “Anisotropic Line Emission and the Geometry of the Broad-Line Region in Active Galactic Nuclei,” The Astrophysical Journal 387, 95 (1992).
Hamann, Fred and Ferland, Gary, “The Age and Chemical Evolution of High-Redshift QSOs,” The Astrophysical Journal 391, L53 (1992).
Ferland, G. J., “Hazy, A Brief Introduction to Cloudy 84,” University of Kentucky Internal Report (1993).
Hamann, Fred and Ferland, Gary, “The Chemical Evolution of QSOs and the Implications for Cosmology and Galaxy Formation,” The Astrophysical Journal 418, 11 (1993).
Shields, Joseph C.; Ferland, Gary J.; and Peterson, Bradley M., “Optically Thin Broad-Line Clouds in Active Galactic Nuclei,” The Astrophysical Journal 441, 507 (1995).
Kingdon, J. and Ferland, G. J., “Collisional Effects in He I: an Observational Analysis,” The Astrophysical Journal 442, 714 (1995).
Wills, Beverley J.; Thompson, Keith L.; Han, Mingsheng, and 6 colleagues, “Hubble Space Telescope Sample of Radio-loud Quasars: Ultraviolet Spectra of the First 31 Quasars,” The Astrophysical Journal 447, 139 (1995).
Baldwin, Jack; Ferland, Gary; Korista, Kirk, and 1 colleague, “Locally Optimally Emitting Clouds and the Origin of Quasar Emission Lines,” The Astrophysical Journal 455, L119 (1995).
Verner, D. A.; Verner, E. M.; and Ferland, G. J., “Atomic Data for Permitted Resonance Lines of Atoms and Ions from H to Si, and S, Ar, Ca, and Fe,” Atomic Data and Nuclear Data Tables 64, 1 (1996).
Ferland, G. J., “Hazy, A Brief Introduction to Cloudy 90,” University of Kentucky Internal Report (1996).
Baldwin, J. A.; Ferland, G. J.; Korista, K. T., and 6 colleagues, “Very High Density Clumps and Outflowing Winds in QSO Broad-Line Regions,” The Astrophysical Journal 461, 664 (1996).
Ferland, Gary J.; Baldwin, Jack A.; Korista, Kirk T., and 5 colleagues, “High Metal Enrichments in Luminous Quasars,” The Astrophysical Journal 461, 683 (1996).
Verner, D. A. and Ferland, G. J., “Atomic Data for Astrophysics. I. Radiative Recombination Rates for H-like, He-like, Li-like, and Na-like Ions over a Broad Range of Temperature,” The Astrophysical Journal Supplement Series 103, 467 (1996).
Verner, D. A.; Ferland, G. J.; Korista, K. T., and 1 colleague, “Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions,” The Astrophysical Journal 465, 487 (1996).
Kingdon, J. B. and Ferland, G. J., “Rate Coefficients for Charge Transfer between Hydrogen and the First 30 Elements,” The Astrophysical Journal Supplement Series 106, 205 (1996).
Korista, Kirk; Baldwin, Jack; Ferland, Gary, and 1 colleague, “An Atlas of Computed Equivalent Widths of Quasar Broad Emission Lines,” The Astrophysical Journal Supplement Series 108, 401 (1997).
Ferguson, Jason W.; Korista, Kirk T.; Baldwin, Jack A., and 1 colleague, “Locally Optimally Emitting Clouds and the Narrow Emission Lines in Seyfert Galaxies,” The Astrophysical Journal 487, 122 (1997).
Ferland, G. J.; Korista, K. T.; Verner, D. A., and 3 colleagues, “CLOUDY 90: Numerical Simulation of Plasmas and Their Spectra,” Publications of the Astronomical Society of the Pacific 110, 761 (1998).
Hamann, Fred and Ferland, Gary, “Elemental Abundances in Quasistellar Objects: Star Formation and Galactic Nuclear Evolution at High Redshifts,” Annual Review of Astronomy and Astrophysics 37, 487 (1999).
Ferland, Gary and Baldwin, Jack, eds., Quasars and Cosmology, ASP Conference Series vol. 162, 1999.
Verner, E. M.; Verner, D. A.; Korista, K. T., and 3 colleagues, “Numerical Simulations of Fe II Emission Spectra,” The Astrophysical Journal Supplement Series 120, 101 (1999).
Hamann, Fred; Korista, K. T.; Ferland, G. J., and 2 colleagues, “Metallicities and Abundance Ratios from Quasar Broad Emission Lines,” The Astrophysical Journal 564, 592 (2002).
Ferland, Gary J., “Quantitative Spectroscopy of Photoionized Clouds,” Annual Review of Astronomy and Astrophysics 41, 517 (2003).
van Hoof, P. A. M.; Weingartner, J. C.; Martin, P. G., and 2 colleagues, “Grain size distributions and photoelectric heating in ionized media,” Monthly Notices of the Royal Astronomical Society 350, 1330 (2004).
Baldwin, J. A.; Ferland, G. J.; Korista, K. T., and 2 colleagues, “The Origin of Fe II Emission in Active Galactic Nuclei,” The Astrophysical Journal 615, 610 (2004).
Shaw, G.; Ferland, G. J.; Abel, N. P., and 2 colleagues, “Molecular Hydrogen in Star-forming Regions: Implementation of its Microphysics in CLOUDY,” The Astrophysical Journal 624, 794 (2005).
Srianand, Raghunathan; Petitjean, Patrick; Ledoux, Cédric, and 2 colleagues, “The VLT-UVES survey for molecular hydrogen in high-redshift damped Lyman α systems: physical conditions in the neutral gas,” Monthly Notices of the Royal Astronomical Society 362, 549 (2005).
Abel, N. P.; Ferland, G. J.; Shaw, G., and 1 colleague, “The H II Region/PDR Connection: Self-consistent Calculations of Physical Conditions in Star-forming Regions,” The Astrophysical Journal Supplement Series 161, 65 (2005).
Osterbrock, Donald E. and Ferland, Gary J., Astrophysics of Gaseous Nebulae and Active Galactic Nuclei, 2nd ed., University Science Books, 2006.
Pellegrini, E. W.; Baldwin, J. A.; Brogan, C. L., and 6 colleagues, “A Magnetically Supported Photodissociation Region in M17,” The Astrophysical Journal 658, 1119 (2007).
Röllig, M.; Abel, N. P.; Bell, T., and 21 colleagues, “A photon dominated region code comparison study,” Astronomy and Astrophysics 467, 187 (2007).
Ferland, G. J.; Fabian, A. C.; Hatch, N. A., and 4 colleagues, “Collisional heating as the origin of filament emission in galaxy clusters,” Monthly Notices of the Royal Astronomical Society 392, 1475 (2009).
Kisielius, R.; Storey, P. J.; Ferland, G. J., and 1 colleague, “Electron-impact excitation of OII fine-structure levels,” Monthly Notices of the Royal Astronomical Society 397, 903 (2009).
Pellegrini, E. W.; Baldwin, J. A.; and Ferland, G. J., “Structure and Feedback in 30 Doradus. II. Structure and Chemical Abundances,” The Astrophysical Journal 738, 34 (2011).
Fabian, A. C.; Sanders, J. S.; Williams, R. J. R., and 3 colleagues, “The energy source of the filaments around the giant galaxy NGC 1275,” Monthly Notices of the Royal Astronomical Society 417, 172 (2011).
Porter, R. L.; Ferland, G. J.; Storey, P. J., and 1 colleague, “Improved He I emissivities in the case B approximation,” Monthly Notices of the Royal Astronomical Society 425, L28 (2012).
Ferland, G. J.; Porter, R. L.; van Hoof, P. A. M., and 6 colleagues, “The 2013 Release of Cloudy,” Revista Mexicana de Astronomia y Astrofisica 49, 137 (2013).
Pei, L.; Fausnaugh, M. M.; Barth, A. J., and 153 colleagues, “Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548,” The Astrophysical Journal 837, 131 (2017).
Edelson, R.; Gelbord, J.; Cackett, E., and 41 colleagues, “Swift Monitoring of NGC 4151: Evidence for a Second X-Ray/UV Reprocessing,” The Astrophysical Journal 840, 41 (2017).
Ferland, G. J.; Chatzikos, M.; Guzmán, F., and 8 colleagues, “The 2017 Release Cloudy,” Revista Mexicana de Astronomia y Astrofisica 53, 385 (2017).
Edelson, R.; Gelbord, J.; Cackett, E., and 32 colleagues, “The First Swift Intensive AGN Accretion Disk Reverberation Mapping Survey,” The Astrophysical Journal 870, 123 (2019).
Olivares, V.; Salome, P.; Combes, F., and 19 colleagues, “Ubiquitous cold and massive filaments in cool core clusters,” Astronomy and Astrophysics 631, A22 (2019).
Kara, Erin; Mehdipour, Missagh; Kriss, Gerard A., and 71 colleagues, “AGN STORM 2. I. First results: A Change in the Weather of Mrk 817,” The Astrophysical Journal 922, 151 (2021).
Chatzikos, M.; Bianchi, S.; Camilloni, F., and 8 colleagues, “The 2023 Release of Cloudy,” Revista Mexicana de Astronomia y Astrofisica 59, 327 (2023).
Ji, Xihan; Maiolino, Roberto; Ferland, Gary; and 14 colleagues, “JADES - The small blue bump in GN-z11: insights into the nuclear region of a galaxy at z=10.6,” Monthly Notices of the Royal Astronomical Society staf1083 (2025).
Search ADS for works by Ferland
Other Works: Popularizations, History, Textbooks , etc.
Miller, Joseph S. and Ferland, Gary J., “Donald E. Osterbrock (1924-2007),” Publications of the Astronomical Society of the Pacific 119, 831 (1998).