MARTIN GASKELL

 


Martin Gaskell

 

Contact Information:
     Office:            RLM 17.202

    Telephone:      (512) 471-1348

    E-mail:            gaskell@astro.as.utexas.edu


Research Interests

    My main area of study is the theory and observations of the violent processes going on around supermassive black holes in quasars and active galactic nuclei (AGNs).  These black holes have masses of up to 10 billion times the mass of our sun, and include the most powerful compact steady-state energy sources in the universe.  The principle goals of my research are (a) to understand what AGNs are like and just how they generate their tremendous energy, and (b) to understand the cosmological evolution of supermassive black holes and their co-relationships with their host galaxies.  This research involves things ranging from theoretical calculations on computers to getting data from the Hubble Space Telescope, a variety of X-ray satellites (such as Chandra, RXTE, and Swift), and from all sorts of ground-based telescopes.  One of my long-term interests has been using the variability of the radiation from AGNs to probe what is going on around the supermassive black holes, and in doing this I work with many astronomers around the world.  As well as working on AGNs I have also worked on supernova explosions, stellar populations in normal galaxies, and astronomical instrumentation.

 

Education

    B.S. - Edinburgh University, Scotland

    M.S. & Ph.D. - University of California at Santa Cruz

 

Recent Papers (from 2007 onwards only)

(present or former student co-authors are followed by an asterisk)

 
Evidence for Two Kinematically Distinct Broad Emission Line Producing Regions in Active Galactic Nuclei

  Snedden, S. A.* & Gaskell, C. M., Astrophys. J. submitted.

A Simple Method for Making Non-Linear Fits to Data Sets with no Independent Error-Free Coordinate

  Gaskell, C. M. Pub. Ast. Soc. Pacific submitted

Line Shifts, Broad-Line Region Inflow, and the Feeding of AGNs
  Gaskell, C. M. & Goosmann, R. W. Astrophys. J. submitted [arXiv:0805.4258]
NGC 5548: The AGN Energy Budget Problem and the Geometry of the Broad-Line Region and Torus 
  Gaskell, C. M., Klimek, E. S.*, & Nazarova, L. S. 2007, Astrophys. J. submitted [arXiv:0711.1025].
AGN Reddening and Ultraviolet Extinction Curves from Hubble Space Telescope Spectra 
  Gaskell, C. M. & Benker, A. J.*, Astrophys. J. submitted [arXiv:0711.1013].
Discovery of Polarization Reverberation in NGC 4151 
  Gaskell, C.M., Goosman, R. W., Merkulova, N. I., Shakhovskoy, N. M., & Shoji, M.* 2007, Astrophys. J. Letts. submitted [arXiv:0711.1019].
 Mem. Soc. Ast. Italiana., 79, 000 [arXiv: 0807.2889]

Accretion Disks and the Nature and Origin of AGN Variability

 Gaskell, C. M. 2008, Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias) 32, 1

Transformations between 2MASS, SDSS, and BVRI Photometric Systems: Bridging the Near Infrared and Optical 
  Bilir, S., Ak, S., Karaali, S., Cabrera-Lavers, A., Chonis, T. S.*, and Gaskell, C. M., 2008, Monthly Notices Royal Astron. Soc. 384, 1178
Setting UBVRI Photometric Zero-Points Using Sloan Digital Sky Survey ugriz Magnitudes 
  Chonis, T. S.* & Gaskell, C. M. 2008, Astron. J., 135, 264
The Case for Optically Thick High-Velocity Broad-Line Region Gas in Active Galactic Nuclei 
  Snedden, S. A.*, & Gaskell, C. M. 2007, Astrophys. J., 669, 126
The Origin of Wavelength-dependent Continuum Delays in AGNs - A New Model 
  Gaskell, C. M. 2007, in The Central Engine of Active Galactic Nuclei: ASP Conf. Ser., 373, 596.
Modeling the Polarization of Dusty Scattering Cones in Active Galactic Nuclei 
  Goosmann, R. W., Gaskell, C. M., & Shoji, M.* 2007 in The Central Engine of Active Galactic Nuclei ASP Conf. Ser., 373, 485.
Hubble Space Telescope Ultraviolet Spectroscopy of 14 Low-Redshift Quasars 
  Ganguly, R, et al., 2007, Astron. J. 133, 479
Modeling optical and UV polarization of AGNs. I. Imprints of individual scattering regions 
  Goosmann, R. W.* & Gaskell, C. M. 2007, Astron. Astrophys., 465, 129.
X-Ray/Ultraviolet Observing Campaign of the Markarian 279 Active Galactic Nucleus Outflow: a close look at the absorbing/emitting gas with Chandra-LETGS 
  Costantini, E, ..., Gaskell, C. M., ... Klimek, E. S.*, & Hedrick, C. H.* 2007, Astron. Astophys. 461, 121.
Chemical Abundances in an AGN Environment: X-Ray/UV Campaign on the Markarian 279 Outflow 
  Arav, N., ... Gaskell, C. M., et al. 2007, Astrophys. J., 658, 829.
AGN Polarization Modelling with STOKES 
  Goosmann, R. W.*, Gaskell, C. M. & Shoji, M.* 2007, IAU Symposium, 238, 375.

 

Older Publications - see ADS

 

Miscellaneous

- Fellow of Royal Astronomical Society (RAS).

- Member of Space and High Energy Astrophysics Commission (Commission 44) of the International Astronomical Union (IAU).

- Member American Astronomical Society (AAS).

- Member High Energy Astrophysics Division (HEAD).

- Five-time finalist for Association of Students of the University of Nebraska annual Outstanding Educator Award

- Nine-time recipient of University of Nebraska Teaching Council and Parents Association Certificate of Recognition for Contributions to Students.

- Mortar Board Professor of the Month (twice)

- Kappa Delta Educator of the Month

- Listed in Who's Who, Who's Who of American Men and Women of Science, and Who's Who of American Educators     


 STOKES Monte Carlo Polarization Code

   My Musical Compositions Page