Derck Massa

SGT, Inc.
Mailstop 681
Goddard Space Flight Center
Greenbelt, MD 20771

Phone: (301) 286-7628



Professional Activities and Awards:

Professional Experience:

  • Individual Scientific Research:
    • Stellar Astronomy: I have been the PI on Chandra, FUSE, HST, IUE (including a 19-th episode key program) and ADP programs aimed at understanding the nature of hot stars. These programs involve research on OB stars (with scientists at JHU, Munich, UCL, Villanova, U. Del and U. Wisc) and Cepheid stars (with scientists at SAO and NASA/GSFC). Topics include methods to determine the masses of classical Cepheids, mass loss and wind variability in OB stars and the determination of iron abundances in main sequence B stars. Results include demonstrating that the winds of LMC O stars are strongly clumped, establishing that the winds of B supergiants are modulated by stellar rotation, developing a new approach to fitting UV wind lines, determining the intrinsic UV continua of O stars, deriving abundances from wind lines, establishing the presence of velocity gradients in the atmospheres of B supergiants, demonstrating the effects of gravitational darkening in late O stars, and developing a UV spectral classification scheme for B stars.
    • Interstellar Medium: I am currently the PI on an ADP program to model the global kinematic and density structure of the galactic halo. Previous work in this area includes modeling the behavior halo gas along specific lines of sight and one of the first global analyses of halo gas. I also made significant contributions to the understanding of the UV extinction of interstellar dust. This includes one of the first demonstrations that the form of interstellar extinction varies (which included one of the first astronomical applications of principle component analysis), an analysis of the systematic errors incurred in UV extinction curve measurements which has become the standard in the field, and a collaboration with Ed Fitzpatrick (Villanova) which established the standard for subsequent work in the field.
    • Instrumentation and data processing: With Endal, I introduced a new approach for resolving specific binaries, including Cepheid systems. This approach is the basis of a current HST program. I am also currently a PI on a NASA AISRP progarm to develop an IUE time series browser. I also have considerable experience in multivariate statistics (including nonlinear problems) and the application of theoretical models.

  • Project Support Work:
    • FUSE Support Scientist: As a support scientist, I am responsible for instrument characterization, science software development and ablsolute flux calibration. I was also involved with supporting the FUSE hot star team in the planning, reduction and analysis of observations of hot stars.
    • UV Acquisition Scientist: As an ingest scientist, I was responsible for negotiating with projects for delivery of their data to the NSSDC, scientific verification of the data upon delivery, and dissemination of the data to the scientific user community. These functions require inter-personal skills, an understanding of a wide range of instrumentation, extensive data analysis skills (outlined above) and an ability to anticipate and respond to the needs of the user community. As part of this activity, I designed several data browsers (including the original IUE browser, whose GIF images are still in use at MAST), and I developed the software pipelines to produce them.
    • Project Management: I was the ARC project manager for its {\it COBE}\/ science support contract, a subcontract to General Sciences Corp. I was responsible for 10 ARC employees, 6 of them PhDs. Our primary roles were the development of scientific calibrations and developing the basic algorithms for the data processing pipelines for both the FIRAS and DIRBE instruments.
    • Director of Astrophysical Sciences: My responsibilities in this capacity were business development, proposal writing, providing guidance for young ARC astronomers in establishing their professional careers, preparing the ARC BAAS Observatory report, and acting as a liaison between ARC astronomers and management.

  • Publications:

    Invited Review: ``Measurements of Interstellar Extinction'', D. Massa and B.D. Savage 1989, in IAU Symp. No 135, ``Interstellar Dust'', eds. L.J. Allamandola and A.G.G.M. Tielens, p. 3

    Papers in Refereed Journals:

    ``Main-Sequence B Stars with Strong Winds in the Core of NGC 6231 II: Verification of the Springmann-Pauldrach Effect?'', D. Massa 2004, in preparation

    ``Wind variability of B supergiants: IV. SEI analysis of time series'', D. Massa, A.W. Fullerton & R.K. Prinja 2004, in preparation

    ``The Angular separations of 2 Galactic Cepheids'', Massa, D., Evans, N.R. 2004, ApJ, in preparation

    ``A search for O VI in the winds of B-type stars'', Zsargó, J., Fullerton, A.W., Lehner, N. & Massa, D. 2003, A&A, 405, 1034

    ``Far Ultraviolet Spectroscopic Explorer Snapshot Survey of O VI Variability in the Winds of 66 OB-Type Stars'', Lehner, N., Fullerton, A.W., Massa, D., Sembach, K.R. & Zsargo, J. 2003, ApJ, 589, 526

    ``Constraints on the Ionization Balance of Hot-Star Winds from FUSE} Observations of O Stars in the Large Magellanic Cloud'', Massa, D., Fullerton, A.W., Sonneborn, G., & Hutchings, J. B. 2003, ApJ, 586, 996

    ``Wind variability of B supergiants. IV. A survey of IUE time-series data of 11 B0 to B3 stars'', Prinja, R.K., Massa, D., \& Fullerton, A.W. 2002, A&A, 388, 587

    ``The Global Content, Distribution, and Kinematics of Interstellar O VI in the Large Magellanic Cloud'' Howk, J.C., Sembach, K.R., Savage, B.D., Massa, D., Friedman, S.D.. & Fullerton, A.W. 2002, ApJ, 569, 214

    ``Fundamental Properties and Distances of the Large Magellanic Cloud from Eclipsing Binaries. II. HV 982'', Fitzpatrick, E.L., Ribas, I., Guinan, E.F., DeWarf, L.E., Maloney, F.P., & Massa, D. 2002, ApJ, 564, 260

    ``The Influence of Stellar Wind Variability on Measurements of Interstellar O VI along Sight Lines to Early-Type Stars'', Lehner, N., Fullerton, A.W., Sembach, K.R., Massa, D.L. & Jenkins, E.B. 2001, ApJ, 556L

    ``Measuring the Ionization of O Star Winds'', Bianchi, L., Hutchings, J.B., Fullerton, A.W., Morton, D.C., Ohl, R.G., Sonneborn, G., Massa, D., Brownsberger, K.R., Willis, A.J. 2000, ApJ, 538, L57

    ``Far Ultraviolet Spectroscopic Explorer Spectroscopy of the O VI Resonance Doublet in Sand 2 (WO)'', Crowther, P.A., Fullerton, A.W., Hillier, D.J., Brownsberger, K., Dessart, L., Willis, A.J., De Marco, O., Barlow, M.J., Hutchings, J.B., Massa, D.L., Morton, D.C., Sonneborn, G. 2000 ApJ, 538, L51

    ``The Detection of Wind Variability in Magellanic Cloud O Stars'', Massa, D., Fullerton, A.W., Hutchings, J.B., Morton, D.C., Sonneborn, G., Willis, A.J., Bianchi, L., Brownsberger, K.R., Crowther, P.A., Snow, T.P., York, D.G. 2000 ApJ, 538, L47

    ``Far Ultraviolet Spectroscopic Explorer Observations of the Stellar Winds of Two O7 Supergiants in the Magellanic Clouds'', Fullerton, A.W., Crowther, P.A., De Marco, O., Hutchings, J.B., Bianchi, L., Brownsberger, K.R., Massa, D.L., Morton, D.C., Rachford, B.L., Snow, T.P., Sonneborn, G., Tumlinson, J., Willis, A.J. 2000 ApJ, 538, L43

    ``On-Orbit Performance of the Far Ultraviolet Spectroscopic Explorer Satellite'', Sahnow, D.J., Moos, H.W., Ake, T.B., Andersen, J., Andersson, B.-G., Andre, M., Artis, D., Berman, A.F., Blair, W.P., Brownsberger, K.R., Calvani, H.M., Chayer, P., Conard, S.J., Feldman, P.D., Friedman, S.D., Fullerton, A.W., Gaines, G.A., Gawne, W.C., Green, J.C., Gummin, M.A., Jennings, T.B., Joyce, J.B., Kaiser, M.E., Kruk, J.W., Lindler, D.J., Massa, D., Murphy, E.M., Oegerle, W.R., Ohl, R.G., Roberts, B.A., Romelfanger, M.L., Roth, K.C., Sankrit, R., Sembach, K.R., Shelton, R.L., Siegmund, O.H.W., Silva, C.J., Sonneborn, G., Vaclavik, S.R., Weaver, H.A., Wilkinson, E. 2000 ApJ, 538, L7

    ``A Recalibration of IUE NEWSIPS Low-Dispersion Data'', Massa, D., Fitzpatrick, E.L. 2000 ApJS, 126, 517

    ``Determining the Physical Properties of the B Stars. I. Methodology and First Results'', Fitzpatrick, E.L., Massa, D. 1999 ApJ, 525, 1011

    ``Toward an Orbit for the High-Luminosity Cepheid T Monocerotis'', ``Evans, N.R., Carpenter, K., Robinson, R., Massa, D., Wahlgren, G.M., Vinko, J., Szabados, L. 1999 ApJ, 524, 379

    ``Transient Infall Events in the Disk of AB Aurigae: The beta Pictoris Phenomenon at 2-4 Megayears'', Grady, C.A., Pérez, M.R., Bjorkman, K.S., Massa, D. 1999 ApJ, 511, 925

    ``Repetitive structure in the stellar wind of HD 93843: a normal O-type star'', Prinja, R.K., Massa, D., Howarth, I.D., Fullerton, A.W. 1998 MNRAS, 301, 926

    ``Time-dependent structure in ultraviolet absorption lines of the rapid rotators HD 64760 (B0Ib) and HD 93521 (O9.5V)'', Howarth, I.D., Townsend, R.H.D., Clayton, M.J., Fullerton, A.W., Gies, D.R., Massa, D., Prinja, R.K., Reid, A.H.N. 1998 MNRAS, 296, 949

    ``Wind variability of B supergiants. III. Corotating spiral structures in the stellar wind of HD 64760'', Fullerton, A.W., Massa, D.L., Prinja, R.K., Owocki, S.P., Cranmer, S.R. 1997 A&A, 327, 699

    ``Wind variability of B supergiants: II. The two-component stellar wind of Gamma Arae'' R.K. Prinja, D. Massa, A.W. Fullerton, I.D. Howarth & M. Pontefract 1997, A&A, 318, 157

    ``The IUE MEGA Campaign: Wind Variability and Rotation in Early-Type Stars'' D. Massa, et. al. 1995 ApJ, 452, L53

    ``The IUE MEGA Campaign: Modulated Structure in the Wind of HD 64760 (B0.5 Ib)'' R.K. Prinja, D. Massa, & A.W. Fullerton 1995 ApJ, 452, L61

    ``The IUE MEGA Campaign: The Rotationally Modulated Wind of zeta Puppis'' I.D. Howarth, R.K. Prinja, & D. Massa 1995 ApJ, 452, L65

    ``Wind Variability in B Supergiants: I. The Rapid Rotator HD 64760 (B0.5 Ib)'', D. Massa, A.Fullerton & R.K. Prinja 1995, ApJ, 452, 842

    ``HD 93521, zeta Oph, and the effects of Rapid Rotation on the Atmospheres and Winds of O9.5 V Stars'' D. Massa 1995, ApJ, 438, 376

    ``S Mus B Revisited'', N.R. Evans, D. Massa & T.J. Teays 1994 AJ, 108, 2251

    ``Calibration of the Far Infrared Absolute Spectrophotometer (FIRAS) on the Cosmic Background Explorer (COBE)'' D.J. Fixen, ... D. Massa, ... 1994 ApJ, 420, 457

    ``Interstellar Extinction in the Infrared: The Molecular Cloud Toward HD 62542'', D.C.B. Whittet, P.G. Martin, E.L. Fitzpatrick, & D. Massa 1993 ApJ, 408, 573

    ``Photospheric Velocity Gradients in B1 Supergiants'', D. Massa, S.N. Shore & D. Wynne 1992 A&A, 264, 169

    ``Ultraviolet Absorption Toward HD 156359, a Halo Star at 11 Kpc in the Direction l = 329° and b = -15°'', K. Sembach, B.D. Savage, & D. Massa 1991, ApJ, 372, 81

    ``Carbon and Nitrogen Abundances in the BN Supergiant HD 93840, and Their Implications for Normal Galactic Supergiants'', D. Massa, B. Altner, D. Wynne & H.J.G.L.M. Lamers, 1991 A&A, 242, 188

    ``An Analysis of the Shapes of UV Extinction Curves III. An Atlas of UV Extinction Curves'', E.L. Fitzpatrick & D. Massa 1990, ApJS, 72, 163

    ``Ultraviolet Interstellar Absorption Toward HD 163522, A Star at 9 Kpc in the Direction l = 350° and b = -9°'', B.D. Savage, D. Massa & K. Sembach 1990, ApJ, 355, 114

    ``The UV Silicon Spectra of Early B Stars'', D. Massa 1989, A&A, 224, 131

    ``An Analysis of the Shapes of UV Extinction Curves II. The Far-UV Extinction'', E.L. Fitzpatrick & D. Massa 1988, ApJ, 328, 734

    ``The Variability of UV Extinction-Curve Shapes and Its Impact Upon Dereddened UV Energy Distributions'', D. Massa 1987, AJ, 94, 1675

    ``An Instrument for Optimizing a Space borne Interferometer: Applications to Calibrating the Cepheid Distance Scale'', D. Massa & A.S. Endal 1987, AJ, 93, 760

    ``Expected Angular Separations of Late-Type Supergiant + B Star Binaries in the Milky Way and LMC'', D. Massa & A.S. Endal 1987, AJ, 93, 579

    ``Ionized Interstellar Gas Located in the Disk and Halo'', B.D. Savage & D. Massa 1987, ApJ, 314, 380

    ``An Analysis of the Shapes of UV Extinction Curves I. The 2175 Å Bump'', E.L. Fitzpatrick & D. Massa 1986, ApJ, 307, 286

    ``The UV Extinction Toward 5 Open Clusters and the Accuracy of IUE Extinction Measurements'', D. Massa & E.L. Fitzpatrick 1986, ApJS, 60, 305

    ``A Catalog of Ultraviolet Interstellar Extinction Excesses for 1415 Stars'', B.D. Savage, D. Massa, M. Meade, & P.R. Wesselius 1985, ApJS, 59, 397

    ``The Intrinsic Ultraviolet Continua of O Stars'', D. Massa & B.D. Savage 1985, ApJ, 299, 905

    ``Absorption by Highly Ionized Gas Near the Galactic Center'', B.D. Savage & D. Massa 1985, ApJ, 295, L9

    ``Main-Sequence B Stars with Strong Winds in the Core of NGC 6231'', D. Massa, B.D. Savage, & J.P. Cassinelli 1984, ApJ, 287, 814

    ``UV Observations of Interstellar Extinction Near the Cep OB3 Molecular Cloud'', D. Massa & B.D. Savage 1984, ApJ, 279, 310

    ``Peculiar UV Interstellar Extinction'', D. Massa, B.D. Savage, & E.L. Fitzpatrick 1983, ApJ, 266, 662

    ``IUE Observations of Eight OB Stars in NGC 2244: UV Continua and Extinction'', D. Massa & P.S. Conti 1981, ApJ, 248, 201

    ``Vector Space Methods of Photometric Analysis. III. The Two Components of Ultraviolet Extinction'', D. Massa 1980, AJ, 85, 1651

    ``Vector Space Methods of Photometric Analysis. II. Refinement of the MK Grid for B Stars'', D. Massa 1980, AJ, 85, 1644

    ``Vector Space Methods of Photometric Analysis: Applications to O Stars and Interstellar Reddening'', D. Massa & C.F. Lillie 1978, ApJ, 221, 833

    ``The influence of Rotation and Stellar Winds upon the Be Phenomenon'', D. Massa 1975, PASP, 87, 777

    In addition to the preceding publications, I have also presented 25 papers at AAS meetings and a variety of conferences.

    Derck Massa
    SGT, Inc.