Dr. Steven B. Kraemer
(Steve)
Astronomer
IACS/CUA and NASA/GSFC

Position: Associate Professor, IACS, Catholic University of America
Mail Address: NASA/Goddard Space Flight Center, Code 681, Greenbelt, MD 20771
Office Location: GSFC - Bldg. 21, T21A; Catholic U. - 214 Hannan Hall
Phone (GSFC): 301-286-8301 or 202-319-4335
Fax (GSFC): 301-286-1752
Email: stiskraemer@yancey.gsfc.nasa.gov

Dr. Kraemer has extensive experience in the modeling of photoionized nebulae, using a computer code developed with J. Patrick Harrington of the University of Maryland, College Park. He is currently working on the analysis of optical and ultraviolet spectra of active galaxies obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph, or STIS (Dr. Kraemer is a co-investigator on the STIS Instrument Development Team.) Specific areas of research, which Kraemer conducts with Dr. Mike Crenhsaw, include:
1) Physical conditions in the gas in the narrow-line regions of Seyfert galaxies. Of particular interest is the question: is this gas ionized solely by EUV-Xray radiation from the central nuclear source or are there other important effects, such as ionization by relativistic particles associated with radio ``jets''?
2) Intrinsic UV absorption lines in active galaxies. These lines appear to be much more common than previously thought. They may be associated with the high-ionization gas outflowing from the nucleus which is detected in absorption in the X-ray. Understanding this process may provide insight into the physical conditions in the innermost regions of the active nucleus.
3) The kinematics of the narrow-line gas in Seyfert galaxies. Understanding the motion of gas in the inner regions of Seyfert galaxies may provide important clues regarding the evolution of this phase of activity.

Curriculum Vitae
Full List of Publications

 

``Physical Conditions in the Emission-Line Gas in the Extremely Low Luminosity Seyfert Nucleus of NGC 4395'', Kraemer, S.B., Ho, L.C., Crenshaw, D.M., Filippenko, A.V., and Shields, J.C. 1999, ApJ, in press.

Preprint (in postscript)

``The Effects of Intrinsic UV Absorbers on the Ionizing Continuum and Narrow Emission Line Ratios in Seyfert Galaxies'', Kraemer, S.B., Turner, T.J., Crenshaw, D.M., and George, I.M. 1999, ApJ, in press.

Preprint (in postscript), Table 1 , Table 2 , Table 3

``Intrinsic Absorption Lines in Seyfert 1 Galaxies. I. Ultraviolet Spectra from the Hubble Space Telescope'', Crenshaw, D.M., Kraemer, S.B., Boggess, A., Maran, S.P., Mushotzky, R.F., and Wu, C.-C. 1999, ApJ, in press.

Preprint (in postscript)

``Physical Conditions in the Inner Narrow-Line Region of the Seyfert 2 Galaxy NGC 1068'', Kraemer, S.B., Ruiz, J.R., and Crenshaw, D.M. 1998, ApJ, in press.

Preprint (in postscript)

``Evidence for a Physically Compact Narrow-Line Region in the Seyfert 1 Galaxy NGC~5548'', Kraemer, S.B., Crenshaw, D.M., Peterson, B.M., and Filippenko, A.V. 1998, ApJ, in press.

Preprint (in postscript)

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