Stephen A Drake

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Stephen A Drake

  • SUPPORT SCIENTIST
  • 301.286.6962 | 301.286.1684
  • NASA/GSFC
  • Mail Code: 662
  • Greenbelt , MD 20771
  • Employer: USRA
  • Brief Bio

    I received my B.Sc. degree in Astrophysics at Edinburgh University in 1973, and my M.A. and Ph.D. degrees in Astronomy at UCLA in 1975 and 1980, respectively. After working at UCLA for a year as a post-doc under my thesis advisor, Dr. Roger Ulrich, I subsequently worked with Dr. Jeffrey Linsky at JILA (U. Colorado) as a post-doc (1981-1985). I joined the Solar Maximum Mission (SMM) Project at NASA/GSFC as a support scientist for the UV Spectrometer/Polarimeter (UVSP) instrument (1985-1991), working with Drs. Bruce Woodgate and Joseph Gurman. After SMM deorbited and the project was wound up, I moved to the then newly created HEASARC data archive as a support scientist in January 1991, where I have worked since then as a support scientist, under the direction of Dr. Nicholas White (1991-2008) and Dr. Alan Smale (2008-present).

    Research Interests

    X-ray emission, radio emission, coronae, magnetospheres, flares, shocks and winds in hot, warm and cool stars, particularly RS CVn binaries and magnetic Ap/Bp stars.

    My major areas of interest are the X-ray emitting plasma produced in the coronae and flares of late-type stars, and in the magnetospheres, shocks and colliding winds of early-type stars. In addition, I have studied the radio continuum, optical, e.g., Ca II H and K, and ultraviolet emission from a wide variety of different types of stars.

    Ranging from the most (~100 solar masses) to least (~0.1 solar masses) massive, the types of stars that I have studied include: (i) Eta Carinae (one of the most massive stars in our Galaxy), (ii) OB stars in the Cygnus OB2 Associations, (iii) Magnetic Bp and Ap stars, (iv) Algol binary systems in which one component fills its Roche Lobe, (v) F stars such as Procyon with thin convection zones, (vi) classic solar-type stars such as Alpha Centauri, (vii) active binary systems such as the RS CVn types, and (viii) dwarf M stars, including the wonderfully named rapidly rotating dMe star 'Speedy Mic' and the flare star EV Lac.

    X-ray spectroscopy of stars can give information about the temperature and density structures, their scale heights, and the prevailing elemental abundances in those parts of their atmospheres where the highest temperatures (1-100 million degrees K) are found. Low- and medium spectral resolution observations made by X-ray detectors on missions such as ROSAT and ASCA yielded in some cases very surprising results, e.g., that the elemental abundances in the coronae of many late-type stars are not the same as those that prevail in their cooler underlying photospheres. These anomalous abundances have been generally confirmed by the high-resolution detectors on the currently operating X-ray observatories, Chandra and XMM-Newton, although there is still little idea as to the physical mechanism(s) that are responsible for them. I am actively working on this topic. The NASA Swift GRB mission has 'accidentally' observed large stellar flares thinking they were GRBs: Rachel Osten, myself and other collaborators have studied several of these, including a 'superflare' of the RS CVn binary II Pegasi which produced both nonthermal hard X-ray emission and low-ionization Fe 6.4 keV emission possibly produced by a collisonally ionizing electron beam.

    Radio continuum emission is another research area in which I have extensively worked, using both the VLA and the ATCA. For late-type evolved stars, emission at cm wavlengths is usually produced by their massive stellar winds, and, if the wind velocity is known, the radio flux can be used to estimate their (ionized) mass loss rate. For magnetic Bp/Ap stars (as first discovered by my collaboration in the mid 1980s) and late-type coronal stars, the dominant radio emission mechanism is gyrosynchrotron emission from mildly relativistic electrons, and the spectrum, intensity and polarization of this can be used to infer the magnetic field strength and energetic particle number density.

    Current Projects

    HEASARC Activities

    At the HEASARC, which is NASA's designated high-energy astrophysics and cosmic microwave background data archive, I have been involved in many activities (in addition to continuing my own research). These include the restoration of older high-energy datasets into modern formats, the addition of new database tables and catalogs to the HEASARC archive database system, the maintenance and updating of various parts of the HEASARC's archive and webpages, including the 'What's New?' rss feed, the Meetings page, the History of High-energy Astronomy, the creation and updating of the statistics on the HEASARC's 50 TB archive contents and downloads (90TB/yr), and the answering of users' questions and complaints that have been sent to the HEASARC's Feedback line, among other things. I am also the designated HEASARC scientist for the RXTE, CGRO, and XMM-Newton projects.

     

     

    Positions/Employment

    1991 - Present

    Scientist

    High Energy Astrophysics Science Archival Research Center, GSFC
    1985 - 1991

    Scientist

    STX (later known as Hughes STX), GSFC
    1981 - 1985

    Post-Doctoral Researcher

    JILA, University of Colorado
    1980 - 1981

    Post-Doctoral Researcher

    Department of Astronomy, UCLA

    Education

    1973 - B.Sc. - Astrophysics, University of Edinburgh
    1975 - M.A. - Astronomy, University of California, Los Angeles
    1980 - Ph.D. - Astronomy, University of California, Los Angeles
    Thesis under the Direction of Dr. Roger Ulrich: 'The Emission Lines and Continuum from a Slab of Hydrogen at Moderate to High Electron Densities'

    Professional Societies

    American Astronomical Society, 1979 - Present
    International Astronomical Union, 1985 - Present
    High Energy Astrophysics Division of the AAS, 1995 - Present

    Selected Publications

    Refereed

    Osten, R. A., O. Godet, S. Drake, et al. J. Tueller, J. Cummings, H. Krimm, J. Pye, V. Pal'shin, S. Golenetskii, F. Reale, S. R. Oates, M. J. Page, and A. Melandri. 2010. "The Mouse That Roared: A Superflare from the dMe Flare Star EV Lac Detected by Swift and Konus-Wind." The Astrophysical Journal 721 785 [Full Text (Link)] [10.1088/0004-637X/721/1/785]

    Osten, R. A., S. Drake, J. Tueller, et al. J. Cummings, M. Perri, A. Moretti, and S. Covino. 2007. "Nonthermal Hard X-Ray Emission and Iron K? Emission from a Superflare on II Pegasi." The Astrophysical Journal 654 1052 [Full Text (Link)] [10.1086/509252]

    Pandey, J. C., K. P. Singh, S. A. Drake, and R. Sagar. 2005. "Optical and X-Ray Studies of Chromospherically Active Stars: FR Cancri, HD 95559, and LO Pegasi." The Astronomical Journal 130 1231 [Full Text (Link)] [10.1086/432539]

    Simon, T., S. M. Andrews, J. T. Rayner, and S. A. Drake. 2004. "X-Ray and Infrared Observations of Embedded Young Stars in L1630." The Astrophysical Journal 611 940 [Full Text (Link)] [10.1086/422187]

    Osten, R. A., A. Brown, T. R. Ayres, et al. S. A. Drake, E. Franciosini, R. Pallavicini, G. Tagliaferri, R. T. Stewart, S. L. Skinner, and J. L. Linsky. 2004. "A Multiwavelength Perspective of Flares on HR 1099: 4 Years of Coordinated Campaigns." The Astrophysical Journal Supplement Series 153 317 [Full Text (Link)] [10.1086/420770]

    McGlynn, T. A., A. A. Suchkov, E. L. Winter, et al. R. J. Hanisch, R. L. White, F. Ochsenbein, S. Derriere, W. Voges, M. F. Corcoran, S. A. Drake, and M. Donahue. 2004. "Automated Classification of ROSAT Sources Using Heterogeneous Multiwavelength Source Catalogs." The Astrophysical Journal 616 1284 [Full Text (Link)] [10.1086/424955]

    Osten, R. A., A. Brown, T. R. Ayres, et al. J. L. Linsky, S. A. Drake, M. Gagné, and R. A. Stern. 2000. "Radio, X-Ray, and Extreme-Ultraviolet Coronal Variability of the Short-Period RS Canum Venaticorum Binary ?2 Coronae Borealis." The Astrophysical Journal 544 953 [Full Text (Link)] [10.1086/317249]

    Padmakar, K. P. Singh, S. A. Drake, and S. K. Pandey. 2000. "Optical, X-ray and radio observations of HD 61396: a probable new RS CVn-type binary." Monthly Notices of the Royal Astronomical Society 314 733 [Full Text (Link)] [10.1046/j.1365-8711.2000.03298.x]

    Corcoran, M. F., A. C. Fredericks, R. Petre, J. H. Swank, and S. A. Drake. 2000. "The X-Ray Spectral Evolution of eta Carinae as Seen by ASCA." The Astrophysical Journal 545 420 [Full Text (Link)] [10.1086/317806]

    Brickhouse, N. S., A. K. Dupree, R. J. Edgar, et al. D. A. Liedahl, S. A. Drake, N. E. White, and K. P. Singh. 2000. "Coronal Structure and Abundances of Capella from Simultaneous EUVE and ASCA Spectroscopy." The Astrophysical Journal 530 387 [Full Text (Link)] [10.1086/308350]

    Brief Bio

    I received my B.Sc. degree in Astrophysics at Edinburgh University in 1973, and my M.A. and Ph.D. degrees in Astronomy at UCLA in 1975 and 1980, respectively. After working at UCLA for a year as a post-doc under my thesis advisor, Dr. Roger Ulrich, I subsequently worked with Dr. Jeffrey Linsky at JILA (U. Colorado) as a post-doc (1981-1985). I joined the Solar Maximum Mission (SMM) Project at NASA/GSFC as a support scientist for the UV Spectrometer/Polarimeter (UVSP) instrument (1985-1991), working with Drs. Bruce Woodgate and Joseph Gurman. After SMM deorbited and the project was wound up, I moved to the then newly created HEASARC data archive as a support scientist in January 1991, where I have worked since then as a support scientist, under the direction of Dr. Nicholas White (1991-2008) and Dr. Alan Smale (2008-present).

    Refereed

    Osten, R. A., O. Godet, S. Drake, et al. J. Tueller, J. Cummings, H. Krimm, J. Pye, V. Pal'shin, S. Golenetskii, F. Reale, S. R. Oates, M. J. Page, and A. Melandri. 2010. "The Mouse That Roared: A Superflare from the dMe Flare Star EV Lac Detected by Swift and Konus-Wind." The Astrophysical Journal 721 785 [Full Text (Link)] [10.1088/0004-637X/721/1/785]

    Osten, R. A., S. Drake, J. Tueller, et al. J. Cummings, M. Perri, A. Moretti, and S. Covino. 2007. "Nonthermal Hard X-Ray Emission and Iron K? Emission from a Superflare on II Pegasi." The Astrophysical Journal 654 1052 [Full Text (Link)] [10.1086/509252]

    Pandey, J. C., K. P. Singh, S. A. Drake, and R. Sagar. 2005. "Optical and X-Ray Studies of Chromospherically Active Stars: FR Cancri, HD 95559, and LO Pegasi." The Astronomical Journal 130 1231 [Full Text (Link)] [10.1086/432539]

    Simon, T., S. M. Andrews, J. T. Rayner, and S. A. Drake. 2004. "X-Ray and Infrared Observations of Embedded Young Stars in L1630." The Astrophysical Journal 611 940 [Full Text (Link)] [10.1086/422187]

    Osten, R. A., A. Brown, T. R. Ayres, et al. S. A. Drake, E. Franciosini, R. Pallavicini, G. Tagliaferri, R. T. Stewart, S. L. Skinner, and J. L. Linsky. 2004. "A Multiwavelength Perspective of Flares on HR 1099: 4 Years of Coordinated Campaigns." The Astrophysical Journal Supplement Series 153 317 [Full Text (Link)] [10.1086/420770]

    McGlynn, T. A., A. A. Suchkov, E. L. Winter, et al. R. J. Hanisch, R. L. White, F. Ochsenbein, S. Derriere, W. Voges, M. F. Corcoran, S. A. Drake, and M. Donahue. 2004. "Automated Classification of ROSAT Sources Using Heterogeneous Multiwavelength Source Catalogs." The Astrophysical Journal 616 1284 [Full Text (Link)] [10.1086/424955]

    Osten, R. A., A. Brown, T. R. Ayres, et al. J. L. Linsky, S. A. Drake, M. Gagné, and R. A. Stern. 2000. "Radio, X-Ray, and Extreme-Ultraviolet Coronal Variability of the Short-Period RS Canum Venaticorum Binary ?2 Coronae Borealis." The Astrophysical Journal 544 953 [Full Text (Link)] [10.1086/317249]

    Padmakar, K. P. Singh, S. A. Drake, and S. K. Pandey. 2000. "Optical, X-ray and radio observations of HD 61396: a probable new RS CVn-type binary." Monthly Notices of the Royal Astronomical Society 314 733 [Full Text (Link)] [10.1046/j.1365-8711.2000.03298.x]

    Corcoran, M. F., A. C. Fredericks, R. Petre, J. H. Swank, and S. A. Drake. 2000. "The X-Ray Spectral Evolution of eta Carinae as Seen by ASCA." The Astrophysical Journal 545 420 [Full Text (Link)] [10.1086/317806]

    Brickhouse, N. S., A. K. Dupree, R. J. Edgar, et al. D. A. Liedahl, S. A. Drake, N. E. White, and K. P. Singh. 2000. "Coronal Structure and Abundances of Capella from Simultaneous EUVE and ASCA Spectroscopy." The Astrophysical Journal 530 387 [Full Text (Link)] [10.1086/308350]

                                                                                                                                                                                            
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