David Ross Boyd Professor, Emeritus
My research focuses on the cosmic chemical evolution of elements in the first three rows of the periodic table, e.g., C, N, O, Ne, S, Cl, and Ar, by studying the interstellar medium (ISM) of galaxies over a broad redshift range. My long-term collaborators include Reggie Dufour (Rice), Karen Kwitter (Williams College), Bruce Balick (U. Washington), Danielle Berg (Ohio State), Evan Skillman (Minnesota), and Dawn Erb (Wisconsin-Milwaukee). Together we measure the interstellar abundances of these elements spectroscopically by observing ISM abundance probes such as H II regions and planetary nebulae. These are regions associated with recent star formation and star death, respectively, in which hot stars heat the surrounding low density nebulae and cause the latter to radiate in discrete emission lines. In turn, these lines are converted into elemental abundances representative of the interstellar material out of which the objects formed.
Once the abundance information becomes available, I then compute both detailed photoionization and chemical evolution models to interpret the results in a galactic context. Lately, our studies have focused on the disks of the Milky Way and M31 galaxies. Our data have recently been obtained during observing runs at McDonald, Gemini North, Kitt Peak, Cerro Tololo, Apache Point, Spitzer Space Telescope, and Hubble Space Telescope observatories.
"On the production of He, C, and N by low- and intermediate-mass stars: a comparison of observed and model-predicted planetary nebula abundances,"R. B. C. Henry, B. G. Stephenson, M. M. Miller Bertolami, K. B. Kwitter and B. Balick,Monthly Notices of the Royal Astronomical Society,473, 241-260, (2018)ADS: 2018MNRAS.473..241HDOI: 10.1093/mnras/stx2286
"Analysis of Co-spatial UV-optical HST/STIS Spectra of Planetary Nebula NGC 3242,"Miller, Timothy R., Henry, Richard B. C., Balick, Bruce, Kwitter, Karen B., Dufour, Reginald J., Shaw, Richard A., Corradi, Romano L. M.,Astrophysical Journal,830(1), 9-20, (2016)ADS: 2016ApJ...830....9MDOI: 10.3847/0004-637X/830/1/9
"Carbon And Oxygen Abundances In Low Metallicity Dwarf Galaxies,"D.A. Berg, E.D. Skillman, R.B.C. Henry, D.K. Erb, L. Carigi,Astrophysical Journal,827(2), 126, (2016)arXiv: https://arxiv.org/abs/1605.06152
"Co-spatial Long-slit UV/Optical Spectra of Ten Galactic Planetary Nebulae with HST/STIS II. Nebular Models, Central Star Properties and He+CNO Synthesis,"R.B.C. Henry, B. Balick, R.J. Dufour, K.B. Kwitter, R.A. Shaw, T.R. Miller, & J.F. Buell ,Astrophysical Journal,813(2), 121, (2015)ADS: 2015ApJ...813..121H
"The Chemistry of Planetary Nebulae in the Outer Regions of M31,"Corradi, R. L. M.; Kwitter, K. B.; Balick, B.; Henry, R. B. C.; Hensley, K.,Astrophysical Journal,807(2), 181, (2015)ADS: 2015ApJ...807..181C
"Co-spatial Long-slit UV/Optical AL Spectra of 10 Galactic Planetary Nebulae with HST/STIS. I. Description of the Observations, Global Emission-line Measurements, and CNO Abundances,"Dufour, Reginald J.; Kwitter, Karen B.; Shaw, Richard A.; Henry, Richard B. C.; Balick, Bruce; Corradi, Romano L. M.,Astrophysical Journal,803, 23, (2015)ADS: 2015ApJ...803...23D
"The Present and Future of Planetary Nebula Research. A White Paper by the IAU Planetary Nebula Working Group,"Kwitter, K. B.; Méndez, R. H.; Peña, M.; Stanghellini, L.; Corradi, R. L. M.; De Marco, O.; Fang, X.; Henry, R. B. C.; Karakas, A. I.; Liu, X.-W.; and 3 coauthors,Revista Mexicana de Astronomía y Astrofísica Vol. 50, pp. 203-223 (2014),50, 203, (2014)ADS: 2014RMxAA..50..203K