Dr. Robert C. Hartman

Astrophysics Science Division
NASA/GSFC
Code 661, Astroparticle Physics Laboratory
Greenbelt, MD 20771

tel: 301-286-7178
fax: 301-286-1682
e-mail: robert.c.hartman @ nasa.gov

Present Position

Astrophysicist

Brief Bio

Bob Hartman began his science career in Peter Meyer's cosmic ray group at the University of Chicago. He participated in the first cosmic ray electron-positron measurements using a balloon-borne magnetic spectrometer; that work was the basis for his PhD thesis.

Bob moved to NASA's Goddard Space Flight Center in 1968, and participated in additional cosmic ray electron-positron observations as well as the SAS-2 high-energy gamma-ray mission in the early 70's.

In the mid-1970's, the Goddard Gamma Ray Astrophysics Branch joined with Stanford University, the Max Planck Institute for Extraterrestrial Physics, and Grumman Aerospace Corporation to start a new telescope, the Energetic Gamma Ray Experiment Telescope (EGRET). Bob's responsibilities during the EGRET development included management of the trigger electronics development as well as the Stanford contract for development of the energy-measurement calorimeter.

When EGRET was launched on the Compton Gamma Ray Observatory (CGRO) by the Space Shuttle Atlantis on April 5, 1991, his emphasis shifted back to astrophysics. He has been involved primarily in high-energy gamma-ray studies of blazars, and has led a large multiwavelength collaboration in studying the emission from blazars over the range from GHz radio through TeV gamma rays.

Currently, Bob is involved with the Gamma-ray Large Area Space Telescope (GLAST), which is being prepared for launch in early 2007. He is working on the AntiCoincidence Detector, an array of 97 detectors to reject charged cosmic-ray particles, which outnumber the gamma rays by a factor of 10,000.

Educational Background

B.A., Physics, Rice Institute, 1960

M.S., Physics, University of Chicago, 1962

Ph.D., Physics, University of Chicago, 1967
("The Energy Dependence of the Positron-Electron Ratio in the Primary Cosmic Radiation in 1965", ApJ, 150, 371, Nov. 1967)

Research Interests

Gamma ray astronomy; instrument development; active galactic nuclei (AGNs), esp. blazars

Current Projects

GLAST/LAT

Selected Publications

"EGRET Diffuse Gamma Ray Maps Between 30 MeV and 10 GeV", A. N. Cillis
and R. C. Hartman, 2005, March, ApJ, 621, 291

"Particle Tracking: Observation and Simulations of the Backsplash
Effects in High-Energy Gamma-Ray Telescopes Containing a Massive
Calorimeter", A. A. Moiseev, J. F. Ormes, R. C. Hartman, T. E. Johnson, J. W. Mitchell, D. J. Thompson 2005, AstroPh, 22/3-4, 275

"Stacking Searches for Gamma-Ray Emission above 100 MeV from Radio and
Seyfert Galaxies", A. N. Cillis and R. C. Hartman, 2004, Jan., ApJ, 601, 142

"Broad-band continuum and line emission of the gamma-ray blazar PKS
0537-441", E. Pian, R. Falomo, R. C. Hartman, L. Maraschi, F. Tavecchio, M. Tornikoski, A. Treves, C. M. Urry, L. Ballo, R. Mukherjee, R. Scarpa, D. J. Thompson, J. E. Pesce, 2002, Sept., A&A, 392, 407

"Day-Scale Variability of 3C 279 and Searches for Correlations in Gamma-Ray, X-Ray, and Optical Bands", R. C. Hartman, M. Villata, T. J.
Balonek, D. L. Bertsch, H. Bock, M. Bottcher, M. T. Carini, W. Collmar, G. De Francesco, E. C. Ferrara, J. Heidt, G. Kanbach, S. Katajainen, M. Koskimies, O. M. Kurtanidze, L. Lanteri, A. Lawson, Y. C. Lin, A. P. Marscher, J. P. McFarland, I. M. McHardy, H. R. Miller, M. Nikolashvili, K. Nilsson, J. C. Noble, G. Nucciarelli, L. Ostorero, T. Pursimo, C. M. Raiteri, R. Rekola, T. Savolainen, A. Sillanpaa A. Smale, G. Sobrito, L. O. Takalo, D. J. Thompson, G. Tosti, S. J. Wagner, J. W. Wilson, 2001, Sept., ApJ, 588, 583

"A Quantitative Evaluation of Potential Radio Identifications for 3EG
EGRET Sources", J. R. Mattox, R. C. Hartman, O. Reimer, 2001, Aug.,
ApJS, 135, 155

"Multiepoch Multiwavelength Spectra and Models for Blazar 3C 279",
Hartman, R. C., Böttcher, M., Aldering, G., Aller, H., Aller, M.,
Backman, D. E., Balonek, T. J., Bertsch, D. L., Bloom, S. D., Bock, H., Boltwood, P., Carini, M. T., Collmar, W., De Francesco, G., Ferrara, E. C., Freudling, W., Gear, W. K., Hall, P. B., Heidt, J., Hughes, P., Hunter, S. D., Jogee, S., Johnson, W. N., Kanbach, G., Katajainen, S., Kidger, M., Kii, T., Koskimies, M., Kraus, A., Kubo, H., Kurtanidze, O., Lanteri, L., Lawson, A., Lin, Y. C., Lisenfeld, U., Madejski, G., Makino, F., Maraschi, L., Marscher, A. P., McFarland, J. P., McHardy, I., Miller, H. R., Nikolashvili, M., Nilsson, K., Noble, J. C., Nucciarelli, G., Ostorero, L., Pian, E., Pursimo, T., aiteri, C. M., Reich, W., Rekola, R., Richter, G. M., Robson, E. I., Sadun, A., Savolainen, T., Sillanpää, A., Smale, A., Sobrito, G., Sreekumar, P., Stevens, J. A., Takalo, L. O., Tavecchio, F., Teräsranta, H., Thompson, D. J., Tornikoski, M., Tosti, G., Ungerechts, H., Urry, C. M., Valtaoja, E., Villata, M., Wagner, S. J., Wehrle, A. E., and Wilson, J. W., 2001, June, ApJ, 553, 683

"Broadband Spectral Analysis of PKS 0528+134: A Report on Six Years of
EGRET Observations", Mukherjee, R., Boettcher, M., Hartman, R.C.,
Sreekumar, P., Thompson, D.J., Mahoney, W.A., Pursimo, T., Sillanpaa,
A., and Takalo, L.O., 1999, Dec., ApJ, 527, 132

"Ultraviolet and Multiwavelength Variability of the Blazar 3C 279:
Evidence for Thermal Emission," Pian, E., Urry, C. M., Maraschi, L.,
Madejski, G., McHardy, I. M., Koratkar, A., Treves, A., Chiappetti, L., Grandi, P., Hartman, R. C., Kubo, H., Leach, C. M., Pesce, J. E.,
Imhoff, C., Thompson, R., Wehrle, A. E., 1999, August, ApJ, 521, 112

"In-Flight Calibration of EGRET on the Compton Gamma-Ray Observatory,"
Esposito, J.A., Bertsch, D.L., Chen, A.W., Dingus, B.L., Fichtel, C.E., Hartman, R.C., Hunter, S.D., Kanbach, G., Kniffen, D.A., Lin, Y.C., Mayer-Hasselwander, H.A., McDonald, L.M., Michelson, P.F., von Montigny, C., Mukherjee, R., Nolan, P.L., Reimer, O., Schneid, E.J., Sreekumar, P., Thompson, D.J., Tompkins, W.F., Willis, T.D., 1999, July, ApJS, 123, 203-217

"The Third EGRET Catalog of High-Energy Gamma-Ray Sources," Hartman,
R.C., Bertsch, D.L., Bloom, S.D., Chen, A.W., Deines-Jones, P.,
Esposito, J.A., Fichtel, C.E., Friedlander, D.P., Hunter, S.D.,
McDonald, L.M., Sreekumar, P., Thompson, D.J., Jones, B.B., Lin, Y.C.,
Michelson, P.F., Nolan, P.L., Tompkins, W.F., Kanbach, G., Mayer-
Hasselwander, H.A., Muecke, A., Pohl, M., Reimer, O., Kniffen, D.A.,
Schneid, E.J., von Montigny, C., Mukherjee, R., Dingus, B.L., 1999,
July, ApJS, 123, 79-202

"Multiwavelength Observations of a Dramatic High-Energy Flare in the
Blazar 3C 279," Wehrle, A.E., Pian E., Urry, C.M., Maraschi, L.,
McHardy, I.M., Lawson, A.J., Ghisellini, G., Hartman, R.C., Madejski,
G.M., Makino F., Marscher, A.P., Wagner, S.J., Webb, J.R., Aldering,
G.S., Aller, M.F., Aller, H.D., Backman, D.E., Balonek, T.J., Boltwood, P., Bonnell, J., Caplinger, J., Celotti, A., Collmar, W., Dalton, J., Drucker, A., Falomo, R., Fichtel, C.E., Freudling, W., Gear, W.K., Gonzales, N., Hall, P., Inoue, H., Johnson, W.N., Kazanas, D., Kidger, M.R., Kii, T., Kollgaard, R.I., Kondo, Y., Kurfess, J., Lin, Y.C., McCollum, B., McNaron-Brown, K., Nagase, F., Nair, A.D., Penton, S., Pesce, J.E., Pohl, M., Raiteri, C.M., Renda, M., Robson, E.I., Sambruna, R.M., Schirmer, A.F., Shrader, C., Sikora, M., Sillanpaa, A., Smith, P.S., Stevens, J.A., Stocke, J., Takalo, L.O., Terasranta, H., Thompson, D.J., Thompson, R., Tornikoski, M., Tosti, G., Treves, A., Turcotte, P., Unwin, S.C., Valtaoja, E., Villata, M., Xu, W., Yamashita, A., and Zook, A., 1998, Apr. 10, ApJ, 497, 178-187

"Observations of a Correlated Gamma-Ray and Optical Flare for BL
Lacertae," Bloom, S.D., Bertsch, D.L., Hartman, R.C., Sreekumar, P.,
Thompson, D.J., Balonek, T.J., Beckerman, E., Davis, S.M., Whitman, K., Miller, H.R., Nair, A.D., Roberts, L.C., Jr., Tosti, G., Massaro, E., Nesci, R., Maesano, M., Montagni, F., Jang, M., Bock, H.A., Dietrich, M., Herter, M., Otterbein, K., Pfeiffer, M., Seitz, T., and Wagner, S., 1997 Dec. 1, ApJ, 490, L145-L148

"EGRET Observations of High-energy Gamma-Ray Emission from Blazars: An
Update," Mukherjee, R., Bertsch, D.L., Bloom, S.D., Dingus, B.L.,
Esposito, J.A., Fichtel, C.E., Hartman, R.C., Hunter, S.D., Kanbach, G., Kniffen, D.A., Lin, Y.C., Mayer-Hasselwander, H.A., McDonald, L.M., Michelson, P.F., von Montigny, C., Muecke, A., Nolan, P.L., Pohl, M., Reimer, O., Schneid, E., Sreekumar, P., Thompson, D.J., 1997, Nov. 20, ApJ, 490, 116-135

"A Spectral Study of Gamma-Ray Emitting Active Galactic Nuclei," Pohl,
M., Hartman, R.C., Jones, B.B., Sreekumar, P., 1997, Oct. 1, A&A, 326,
51-58

"Multiwavelength Observations of 3C 273 in 1993-1995," von Montigny, C., Aller, H., Aller, M., Bruhweiler, F., Collmar, W., Courvoisier, T.J.-L., Edwards, P.G., Fichtel, C.E., Fruscione, A., Ghisellini, G., Hartman, R.C., Johnson, W.N., Kafatos, M., Kii, T., Kniffen, D.A., Lichti, G.G., Makino, F., Mannheim, K., Marscher, A.P., McBreen, B., McHardy, I., Pesce, J.E., Pohl, M., Ramos, E., Reich, W., Robson, E.I., Sasaki, K., Terasranta, H., Tornikoski, M., Urry, C.M., Valtaoja, E., Wagner, S. and Weekes, T., 1997, July 1, ApJ, 483, 161-177

"The Idenfication of EGRET Sources with Flat-Spectrum Radio Sources,"
Mattox, J.R., Schachter, J., Molnar, L., Hartman, R.C., Patnaik, A.R.,
1997, May 20, ApJ, 481, 95-115

"Detection of Gamma Rays with E>100 MeV From BL Lacertae," Catanese, M., Akerlof, C.W., Biller, S.D., Boyle, P., Buckley, J.H., Carter-Lewis, D.A., Cawley, M.F., Connaughton, V., Dingus, B.L., Fegan, D.J., Fichtel, C.E., Finley, J.P., Gaidos, J.A., Gear, W.K., Hartman, R.C., Hillas, A.M., Krennrich, F., Lamb, R.C., Lessard, R.W., Lin, Y.C., McEnery, J.E., Marscher, A.P., Mohanty, G., Mukherjee, R., Quinn, J., Robson, E.I., Rodgers, A.J., Rose, H.J., Samuelson, F.W., Sembroski, G., Schubnell, M.S., Stevens, J.A., Terasranta, H., Thompson, D.J., Weekes, T.C., Wilson, C., and Zweerink, J., 1997 May 10, ApJ, 480, 562-567

"Simultaneous Multiwavelength Spectrum and Variability of 3C 279 from
109 to 1024 Hz," Hartman, R.C. Webb, J.R., Marscher, A.P., Travis, J.P., Dermer, C.D., Aller, H.D., Aller, M.F., Balonek, T.J., Bennett, K., Bloom, S.D., Fujimoto, R., Hermsen, W., Hughes, P., Jenkins, P., Kii, T., Kurfess, J.D., Makino, F., Mattox, J.R., von Montigny, C., Ohashi, T., Robson, I., Ryan, J., Sadun, A., Schönfelder, V., Smith, A.G., Terasranta, H., Tornikoski, M., Turner, M.J.L., 1996, ApJ, 461, 698

"Time Variability in the Gamma-Ray Emission of 3C 279," Kniffen, D. A., Bertsch, D. L., Fichtel, C. E., Hartman, R. C., Hunter, S. D., Kanbach, G., Kwok, P. W., Lin, Y. C., Mattox, J. R., Mayer- Hasselwander, H. A., Michelson, P. F., von Montigny, C., Nolan, P. L., Pinkau, K., Schneid, E., Sreekumar, P., and Thompson, D. J., 1993, ApJ, 411, 133

"EGRET Detection of High-Energy Gamma Radiation from the OVV Quasar 3C
454.3," Hartman, R. C., Bertsch, D. L., Dingus, B. L., Fichtel, C. E.,
Hunter, S. D., Kanbach, G., Kniffen, D. A., Lin, Y. C., Mattox, J. R.,
Mayer-Hasselwander, H. A., Michelson, P. F., von Montigny, C., Nolan, P. L., Piner, B. G., Schneid, E., Sreekumar, P., and Thompson, D. J., 1993, ApJ, 407, L41

"EGRET Observations of 3C273," von Montigny, C., Bertsch, D. L.,
Fichtel, C. E., Hartman, R. C., Hunter, S. D., Kanbach, G., Kniffen, D. A., Kwok, P. W., Lin, Y. C., Mattox, J. R., Mayer- Hasselwander, H. A., Michelson, P. F., Nolan, P. L., Pinkau, K., Rothermel, H., Schneid, E., Sommer, M., Sreekumar, P., and Thompson, D. J., 1993, A&A, 97, 101

"Detection of High Energy Gamma Radiation From Quasar 3C 279 by the
EGRET Telescope on the Compton Gamma Ray Observatory", Hartman, R. C., Bertsch, D. L., Fichtel, C. E., Hunter, S. D., Kanbach, G., Kniffen, D. A., Kwok, P. W., Lin, Y. C., Mattox, J. R., Mayer-Hasselwander, H. A., Michelson, P. F., Pinkau, K., Rothermel, H., Schneid, E., Sommer, M., Sreekumar, P., and Thompson, D., 1992, ApJ Letters, 385, 1