dballantyne3

David Ballantyne
Associate Professor / Associate Chair for Graduate Program
Education
Ph.D. in Astronomy, University of Cambridge 2002
M.Sc. in Astronomy & Physics, University of Toronto 1999
B.Sc. in Honours Physics & Astronomy, University of Victoria 1998
Research Interests

high-energy astrophysics; accretion disks; galaxy and black hole evolution

My research concentrates on topics in high-energy astrophysics with an emphasis on interpreting existing data and making predictions for future observations. My main interests are: (i) the evolution of galaxies and their central supermassive black holes and (ii) the physics of accretion disks around both black holes and neutron stars. My work often involves comparing computer based models with published data from X-ray, radio and/or infrared telescopes. All of these directions are guided by my underlying research philosophy of using any necessary tool or technique, unlimited by wavelength range or physical process, to make progress in understanding the relevant physics. Students working with me will be exposed to a wide range of astrophysical processes and theories, but will also learn to respect and be guided by observational constraints.

Papers:

Papers Since Arriving at Georgia Tech

  1. Masini, A., Ciavno, F., Comastri, A., Fornasini, F., Ballantyne, D.R., Lansbury, G., Treister, E., Alexander, D.M., Boorman, P.G., Brandt, W.N., Farrah, D., Gandhi, P., Harrison, F.A., Hickox, R.C., Kocevski, D.D., Lanz, L., Marchesi, S., Puccetti, S., Ricci, C., Saez, C., Stern, D. & Zappacosta, L., 2017, The NuSTAR Extragalactic Surveys: Source Catalog and the Compton-Thick Fraction in the UDS Field, submitted to The Astrophysical Journal.

  2. Degenaar, N., Ballantyne, D.R., Belloni, T., Chakraborty, M., Chen, Y.-P., Ji, L., Kretschmar, P., Kuulkers, E., Li, J., Maccarone, T.J., Malzac, J., Zhang, S. & Zhang, S.-N., 2017, Accretion disks and coronae in the X-ray flashlight, submitted to Space Science Reviews.

  3. Zappacosta, L., Comastri, A., Civano, F., Puccetti, S., Fiore, F., Aird, J., Del Moro, A., Lansbury, G.B., Lanzuisi, G., Goulding, A., Mullaney, J.R., Stern, D., Ajello, M., Alexander, D.M., Ballantyne, D.R., Bauer, F.E., Brandt, W.N., Chen, C.-T.J., Farrah, D., Harrison, F.A., Gandhi, P., Lanz, L., Masini, A., Marchesi, S., Ricci, C. & Treister, E., 2017, The NuSTAR Extragalactic Surveys: X-ray Spectroscopic Analysis of the Bright Hard-Band Sample, submitted to The Astrophysical Journal.

  4. Buisson, D.J.K., Parker, M.L., Kara, E., Vasudevan, R.V., Lohfink, A.M., Pinto, C., Fabian, A.C., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Craig, W.W., Farrah, D., Hailey, C.J., Harrison, F.A., Ricci, C., Stern, D., Walton, D.J., Zhang, W.W., 2017, NuSTAR observations of Mrk 766: distinguishing reflection from absorption, submitted to The Monthly Notices of the Royal Astronomical Society.

  5. Sartori, L.F., Schawinski, K, Koss, M.J., Ricci, C., Treister, E., Stern, D., Lansbury, G., Maksym, W.P., Baloković, M., Gandhi, P., Keel, W.C. & Ballantyne, D.R., 2017, Joint NuSTAR and Chandra analysis of the obscured quasar in IC 2494 – Hanny's Voorwerp system, submitted to the Monthly Notices of the Royal Astronomical Society.

  6. Porquet, D., Reeves, J.N., Matt, G., Marinucci, A., Nardini, E., Braito, V., Lobban, A., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Dauser, T., Farrah, D., Garcia, J., Hailey, C.J., Harrison, F., Stern, D., Tortosa, A., Ursini, F. & Zhang, W.W., 2017, A deep X-ray view of the bare AGN Ark 120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes, Astronomy & Astrophysics, in press.

  7. Del Moro, A., Alexander, D.M., Aird, J.A., Bauer, F.E., Civano, F., Mullaney, J.R., Ballantyne, D.R., Brandt, W.N., Comastri, A., Gandhi, P., Harrison, F.A., Lansbury, G.B., Lanz, L., Luo, B., Marchesi, S., Puccetti, S., Ricci, C., Saez, C., Stern, D., Treister, E. & Zappacosta, L., 2017, The NuSTAR Extragalactic Survey: Average Broad-band X-ray Spectral Properties of the NuSTAR Detected AGN, The Astrophysical Journal, Vol. 849, p. 57.

  8. Ballantyne, D.R., 2017, Ionised Accretion Discs in Active Galactic Nuclei: The Effects of a Lamppost with a Variable Height, The Monthly Notices of the Royal Astronomical Society Letters, Vol. 472, p. L60.

  9. Lansbury, G.B., Alexander, D.M., Aird, J., Gandhi, P., Stern, D., Koss, M., Ajello, M., Assef, R.J., Ballantyne, D.R., Baloković , M., Bauer, F.E., Brandt, W.N., Brightman, M., Chen, C.-T.J., Civano, F., Comastri, A., Del Moro, A., Fuentes, C., Harrison, F.A., Marchesi, S., Masini, A., Mullaney, J.R., Ricci, C., Saez, C., Tomsick, J.A., Treister, E., Walton, D.J. & Zappacosta, L., 2017, The NuSTAR Serendipitous Survey: Hunting for the Most Extreme Obscured AGN at > 10 keV, The Astrophysical Journal, Vol. 846, p. 20.

  10. Brightman, M., Baloković , M., Ballantyne, D.R., Bauer, F.E., Boorman, P., Buchner, J., Brandt, W.N., Comastri, A., Del Moro, A., Farrah, D., Harrison, F.A., Koss, M., Lanz, L., Masini, A., Ricci, C., Stern, D., Vasudevan, R. & Walton, D.J., 2017, X-ray Bolometric Corrections for Compton-Thick Active Galactic Nuclei, The Astrophysical Journal, Vol. 844, p. 10.

  11. Lohfink, A.M., Fabian, A.C., Ballantyne, D.R., Boggs, S.E., Boorman, P., Christensen, F.E., Craig, W.W., Farrah, D., García, J., Hailey, C.J., Harrison, F.A., Ricci, C., Stern, D. & Zhang, W.W., 2017, The X-Ray Reflection Spectrum of the Radio-Loud Quasar 4C 74.26, The Astrophysical Journal, Vol. 841, p. 80.

  12. Gohil, R. & Ballantyne, D.R., 2017, Modeling the Vertical Structure of Nuclear Starburst Discs: A Possible Source of AGN Obscuration at z~1, Monthly Notices of the Royal Astronomical Society, Vol. 468, p. 4944.

  13. Annuar, A., Alexander, D.M., Gandhi, P., Lansbury, G.B., Asmus, D., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Boorman, P.G., Brandt, W.N., Brightman, M., Christensen, F.E., Craig, W.W., Farrah, D., Goulding, A.D., Hailey, C.J., Harrison, F.A., Koss, M.J., LaMassa, S.M., Murray, S.S., Ricci, C., Rosario, D.J., Stanley, F., Stern, D. & Zhang, W., 2017, A New Compton­-Thick AGN in Our Cosmic Backyard: Unveiling the Buried Nucleus in NGC 1448 with NuSTAR, The Astrophysical Journal, Vol. 836, p. 165.
  14. Totosa, A., Marinucci, A., Matt, G., Bianchi, S., La Franca, F., Ballantyne, D.R., Boorman, P.G., Fabian, A.C., Farrah, D., Fuerst, F., Gandhi, P., Harrison, F.A., Koss, M.J., Ricci, C., Stern, D., Ursini, F. & Walton, D.J., 2017, Broadband X-ray spectral analysis of the Seyfert 1 galaxy GRS 1734-292, The Monthly Notices of the Royal Astronomical Society, Vol. 466, p. 4193.

  15. Keek, L., Iwakiri, W., Serino, M., Ballantyne, D.R., in ‘t Zand, J.J.M. & Strohmayer, T.E., 2017, X-ray Reflection and an Exceptionally Long Thermonuclear Helium Burst from IGR J17062-6143, The Astrophysical Journal, Vol. 836, p. 111.

  16. Zoghbi, A., Matt, G., Miller, J.M., Lohfink, A.M., Walton, D.J., Ballantyne, D.R., García, J.A., Stern, D., Koss, M.J., Farrah, D., Harrison, F.A., Boggs, S.E., Christensen, F.E., Craig, W., Hailey, C.J. & Zhang, W.W., 2017, A Long Look at MCG-5-23-16 with NuSTAR: I. - Relativistic Reflection and Coronal Properties, The Astrophysical Journal, Vol. 836, p. 2.

  17. Lansbury, G., Stern, D., Aird, J., Alexander, D.M., Fuentes, C., Harrison, F.A., Treister, E., Bauer, F.E., Tomsick, J.A., Baloković, M., Del Moro, A., Gandhi, P., Ajello, M., Annuar, A., Ballantyne, D.R., Boggs, S.E., Brandt, W.N., Brightman, M., Chen, C.­T.J., Christensen, F.E., Civano, F., Comastri, A., Craig, W.W., Forster, K., Grefenstette, B.W., Hailey, C.J., Hickox, R.C., Jiang, B., Jun, H.D., Koss, M., Marchesi, S., Melo, A.D., Mullaney, J.R., Noirot, G., Schulze, S., Walton, D.J., Zappacosta, L. & Zhang, W.W., 2017, The NuSTAR Serendipitous Survey: The 40 Month Catalog and the Properties of the Distant High Energy X­-ray Source Population, The Astrophysical Journal, in press, Vol. 836, p. 99.
  18. Ricci, C., Assef, R.J., Stern, D., Nikutta, R., Alexander, D.M., Asmus, D., Ballantyne, D.R., Bauer, F.E., Blain, A.W., Boggs, S., Boorman, P.G., Brandt, W.N., Brightman, M., Chen, C.­T.,J., Christensen, F.E., Comastri, A., Craig, W.W., Díaz­-Santos, T., Eisenhardt, P.R., Farrah, D., Gandhi, P., Hailey, C.J., Harrison, F.A., Jun, H.D., Koss, M.J., LaMassa, S., Lansbury, G., Markwardt, C.B., Stalevski, M., Stanley, F., Treister, E., Tsai, C.­W., Walton, D.J., Wu, J.W. & Zhang, W.W., 2017, NuSTAR Observations of WISE J1036+0449, A Galaxy at z~1 Obscured by Hot Dust, The Astrophysical Journal, Vol. 835, p. 105.
  19. Ballantyne, D.R., 2017, Clustering, Cosmology and a New Era of Black Hole Demographics – I. The Conditional Luminosity Function of Active Galactic Nuclei, Monthly Notices of the Royal Astronomical Society, Vol. 464, p. 613.
  20. Ballantyne, D.R., 2017, Clustering, Cosmology and a New Era of Black Hole Demographics – II. The Conditional Luminosity Functions of Type 2 and Type 1 Active Galactic Nuclei, Monthly Notices of the Royal Astronomical Society, Vol. 464, p. 626.
  21. Boorman, P.G., Gandhi, P., Alexander, D.M., Annuar, A., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Craig, W.W., Farrah, D., Hailey, C.J., Harrison, F.A., Hönig, S.F., Koss, M., LaMassa, S.M., Masini, A., Ricci, C., Risaliti, G., Stern, D. & Zhang, W.W., 2016, IC 3639 – A New Bona Fide Compton Thick AGN Unveiled by NuSTAR, The Astrophysical Journal, Vol. 833, p. 245.
  22. Rujopakarn, W., Dunlop, J.S., Rieke, G.H., Ivison, R.J., Cibinel, A., Nyland, K., Jagannathan, P., Silverman, J.D., Alexander, D.M., Biggs, A.D., Bhatnagar, S., Ballantyne, D.R., Dickinson, M., Elbaz, D., Geach, J.E., Hayward, C.C., Kirkpatrick, A., McLure, R.J., Michałowski, M.J., Miller, N.A., Narayanan, D., Owen, F.N., Pannella, M., Papovich, C., Pope, A., Rau, U., Robertson, B.E., Scott, D., Swinbank, A.M., van der Werf, P., van Kampen, E. & Windhurst, R.A., 2016, VLA and ALMA Imaging of Intense, Galaxy­-Wide Star Formation in z~2 Galaxies, The Astrophysical Journal, Vol. 833, p. 12.
  23. Harrison, F.A., Aird, J., Civano, F., Lansbury, G., Mullaney, J.R., Ballantyne, D.R., Alexander, D.M., Stern, D., Ajello, M., Barret, D., Bauer, F.E., Baloković, M., Brandt, W.N., Brightman, M., Boggs, S.E., Christensen, F.E., Comastri, A., Craig, W.W., Del Moro, A., Forster, K., Gandhi, P., Giommi, P., Grefenstette, B.W., Hailey, C.J., Hickox, R.C., Hornstrup, A., Kitaguchi, T., Koglin, J., Luo, B., Madsen, K.K., Mao, P.H., Miyasaka, H., Mori, K., Perri, M., Pivovaroff, M., Puccetti, S., Rana, V., Treister, E., Walton, D., Westergaard, N.J., Wik, D., Zappacosta, L., Zhang, W.W. & Zoglauer, A., 2016, The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-­ray Background, The Astrophysical Journal, Vol. 831, p.185.
  24. Farrah, D., Baloković, M., Stern, D., Harris, K., Alexander, D.M., Arévalo, P., Ballantyne, D.R., Bauer, F.E., Boggs, S., Brandt, W.N., Brightman, M., Christensen, F., Clements, D.L., Craig, W., Fabian, A., Hailey, C., Harrison, F., Koss, M., Kunimoto, M., Lansbury, G.B., Luo, B., Paine, J., Petty, S., Pitchford, K., Ricci, C., Walton, D.J. & Zhang, W., 2016, The Geometry of the Infrared and X­-ray Obscurer in a Dusty Hyperluminous Quasar, The Astrophysical Journal, Vol. 831, p. 76.
  25. Brightman, M., Masini, A., Ballantyne, D.R., Baloković, M., Brandt, W.N., Chen, C.­T., Comastri, A., Farrah, D., Gandhi, P., Harrison, F.A., Ricci, C., Stern, D. & Walton, D.J., 2016, A Growth­ Rate Indicator for Compton­-Thick Active Galactic Nuclei, The Astrophysical Journal, Vol. 826, p. 93.
  26. Keek, L., Wolf, Z. & Ballantyne, D.R., 2016, Accretion Disk Signatures in Type I X-ray Bursts: Prospects for Future Missions, The Astrophysical Journal, Vol. 826, p. 79.
  27. Koss, M.J., Assef, R., Baloković, M., Stern, D., Gandhi, P., Lamperti, I., Alexander, D.M., Ballantyne, D.R., Bauer, F.E., Berney S., Brandt, W.N., Comastri, A., Gehrels, N., Harrison, F.A., Lansbury, G., Markwardt, C., Ricci, C., Rivers, E., Schawinski, K., Trakhtenbtot, B., Treister, E. & Urry, C.M., 2016, A New Population of Compton­ Thick AGNs Identified Using the Spectral Curvature Above 10 keV, The Astrophysical Journal, Vol., 825, p. 85.
  28. Koss, M.J., Glidden, A., Baloković, M., Stern, D., Lamperti, I., Assef, R., Bauer, F., Ballantyne, D., Boggs, S.E., Craig, W.W., Farrah, D., Füerst, F., Gandhi, P., Gehrels, N., Hailey, C.J., Harrison, F.A., Markwardt, C., Masini, A., Ricci, C., Treister, E., Walton, D.J. & Zhang, W.W., 2016, NuSTAR Resolves the First Dual AGN Above 10 keV in SWIFT J2028.5+2543, The Astrophysical Journal, Vol. 824, L4.
  29. Lanzuisi, G., Perna, M., Comastri, A., Cappi, M., Dadina, M., Marinucci, A., Masini, A., Matt, G., Vagnetti, F., Vignali, C., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brusa, M., Christensen, F.E., Craig, W.W., Fabian, A.C., Farrah, D., Hailey, C.J., Harrison, F.A., Luo, B., Piconcelli, E., Puccetti, S., Ricci, C., Saez, C., Stern, D., Walton, D.J. & Zhang, W.W., 2016, NuSTAR Reveals the Extreme Properties of the super­-Eddington Accreting Supermassive Black Hole in PG 1247+267, Astronomy & Astrophysics, Vol. 590, p. A77.
  30. Masini, A., Comastri, A., Baloković, M. Zaw, I., Puccetti, S., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Craig, W.W., Gandhi, P., Hailey, C.J., Harrison, F.A., Koss, M.J., Madejski, G., Ricci, C., Rivers, E., Stern, D. & Zhang, W.W., 2016, NuSTAR Observations of Water Megamaser AGN, Astronomy & Astrophysics, Vol. 589, p. A59.
  31. Keek, L. & Ballantyne, D.R., 2016, Revealing the accretion disc corona in Mrk 335 with multi­-epoch X­-ray spectrocscopy, Monthly Notices of the Royal Astronomical Society, Vol. 456, p. 2722.
  32. Aird, J., Alexander, D.M., Ballantyne, D.R., Civano, F., Del­Moro, A., Hickox, R.C., Lansbury, G.B., Mullaney, J.R., Bauer, F.E., Brandt, W.N., Comastri, A., Fabian, A.C., Gandhi, P., Harrison, F.A., Luo, B., Stern, D., Treister, E., Zappacosta, L., Ajello, M., Assef, R., Balković, M., Boggs, S.E., Brightman, M., Christensen, F.E., Craig, W.W., Elvis, M., Forster, K., Grefenstette, B.W., Hailey, C.J., Koss, M., LaMassa, S.M., Madsen, K.K., Puccetti, S., Saez, C., Urry, C.M., Wik, D.R. & Zhang, W., 2015, The NuSTAR Extragalactic Survey: First Direct Measurement of the > 10 keV X­-ray Luminosity Function for Active Galactic Nuclei at z > 0.1, The Astrophysical Journal, Vol. 815, p. 66.
  33. Annur, A., Gandhi, P., Alexander, D.M., Lansbury, G.B., Arévalo, P., Ballantyne, D.R., Baloković, M., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Craig, W.W., Del Moro, A., Hailey, C.J., Harrison, F.A., Hickox, R.C., Matt, G., Puccetti, S., Ricci, C., Rigby, J.R., Stern, D., Walton, D.J., Zappacosta, L & Zhang, W., 2015, NuSTAR Observations of the Compton­ Thick Active Galactic Nucleus and Ultraluminous X­ray Source Candidate in NGC 5643, The Astrophysical Journal, Vol. 815, p. 36.
  34. Lohfink, A.M., Tombesi, F., Walton, D., Balković, M., Zoghbi, A., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Craig, W.W., Fabian, A.C., Hailey, C.J., Harrison, F.A., King, A.L., Madjeski, G., Matt, G., Ogle, P., Reynolds, C.S., Stern, D., Ursini, F. & Zhang, W.W., 2015, The Corona of the Broad­-Line Radio Galaxy 3C 390.3, The Astrophysical Journal, Vol. 814, p. 24.
  35. Keek, L., Cumming, A., Wolf, Z., Ballantyne, D.R., Suleimanov, V.F., Kuulkers, E. & Strohmayer, T.E., 2015, The imprint of carbon combustion on a superburst from the accreting neutron star 4U 1636­-536, The Monthly Notices of the Royal Astronomical Society, Vol. 454, p. 3559.
  36. Madsen, K.K., Fürst, F., Walton, D.J., Harrison, F.A., Ballantyne, D.R., Boggs, S.E., Brenneman, L.W., Christensen, F.E., Craig, W.W., Fabian, A.C., Forster, K., Grefenstette, B.W., Guainazzi, M., Hailey, C.J., Madejski, G.M., Matt, G., Stern, D. & Zhang, W.W., 2015, 3C 273 with NuSTAR: Unveiling the AGN, The Astrophysical Journal, Vol. 812, p. 14.
  37. Lansbury, G.B., Gandhi, P., Alexander, D.M., Assef, R.J., Annur, A., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Civano, F., Comastri, A., Craig, W.W., Del Moro, A., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Hickox, R.C., Koss, M., LaMassa, S.M., Luo, B., Puccetti, S., Stern, D., Treister, E., Vignali, C., Zappacosta, L. & Zhang, W.W., 2015, NuSTAR Reveals Extreme Absorption in z  ≾  0.5 Type 2 Quasars, The Astrophysical Journal, Vol. 809, p. 115.
  38. Civano, F., Hickox, R., Puccetti, S., Comastri, A., Mullaney, J., Zappacosta, L., LaMassa, S., Aird, J., Alexander, D.M., Ballantyne, D.R., Bauer, F.E., Brandt, W.N., Boggs, S.E., Christensen, F.E., Craig, W.W., Del-Moro, A., Elvis, M., Forster, K., Gandhi, P., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Lansbury, G.B., Luo, B., Madsen, K., Saez, C., Stern, D., Treister, E., Urry, C.M., Wik, D.R. & Zhang, W.W., 2015, The NuSTAR Extragalactic Surveys: Overview and Catalog from the COSMOS Field, The Astrophysical Journal, Vol. 808, p. 185.
  39. Mullaney, J.R., Del-Moro, A., Aird, J., Alexander, D.M., Civano, F.M., Hickox, R.C., Lansbury, G.B., Ajello, M., Assef, R., Ballantyne, D.R., Baloković, M., Bauer, F.E., Brandt, W.N., Boggs, S.E., Brightman, M., Christensen, F.E., Comastri, A., Craig, W.W., Elvis, M., Forster, K., Gandhi, P., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Koss, M., LaMassa, S.M., Luo, B., Madsen, K.K., Puccetti, S., Saez, C., Stern, D., Treister, E., Urry, C.M., Wik, D.R., Zappacosta, L. & Zhang, W., 2015, The NuSTAR Extragalactic Surveys: Initial Results and Catalog from the Extended Chandra Deep Field South, The Astrophysical Journal, Vol. 808, p. 184.
  40. Ursini, F., Marinucci, A., Matt, G., Bianchi, S., Tortosa, A., Stern, D., Arévalo, P., Ballantyne, D.R., Bauer, F.E., Fabian, A.C., Harrison, F.A., Lohfink, A.M., Reynolds, C.S. & Walton, D.J., 2015, The NuSTAR X-ray spectrum of the low-luminosity active galactic nucleus in NGC 7213, Monthly Notices of the Royal Astronomical Society, Vol. 452, p. 3272.
  41. Reynolds, C.S., Lohfink, A.M., Ogle, P.M., Harrison, F.A., Madsen, K.K., Fabian, A.C., Wik, D.R., Madejski, G., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Craig, W.W., Fuerst, F., Hailey, C.J., Lanz, L., Miller, J.M., Saez, C., Stern, D., Walton, D.J. & Zhang, W., 2015, NuSTAR Observations of the Powerful Radio­-Galaxy Cygnus A, The Astrophysical Journal, Vol. 808, p. 154.
  42. Koss, M.J., Romero-Cañizales, C., Teng, S.H., Baloković, M., Puccetti, S., Bauer, F.E., Arévalo, P., Assef, R., Ballantyne, D.R., Baronchelli, L., Brandt, W.N., Brightman, M., Comastri, A., Gandhi, P., Harrison, F.A., Luo, B., Schawinski, K., Stern, D. & Treister, E., 2015, Broadband Observations of the Compton-Thick Nucleus of NGC 3393, The Astrophysical Journal, Vol. 807, p. 149.
  43. Keck, M.L., Brenneman, L.W., Ballantyne, D.R., Bauer, F., Boggs, S.E., Christensen, F.E., Craig, W.W., Dauser, T., Elvis, M., Fabian, A.C., Fuerst, F., Garćia, J., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Madejski, G., Marinucci, A., Matt, G., Reynolds, C.S., Stern, D., Walton, D.J. & Zoghbi, A., 2015, NuSTAR and Suzaku X-ray Spectroscopy of NGC 4151: Evidence for Reflection from the Inner Accretion Disk, The Astrophysical Journal, Vol. 806, p. 149.
  44. Brightman, M., Baloković, M., Stern, D., Arévalo, P., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Craig, W.W., Christensen, F.E., Comastri, A., Fuerst, F., Gandhi, P., Hailey, C.J., Harrison, F.A., Hickox, R., Koss, M., LaMassa, S., Puccetti, S., Rivers, L., Vasudevan, R., Walton, D.J. & Zhang, W.W., 2015, Determining the Covering Factor of Compton-thick Active Galactic Nuclei with NuSTAR, The Astrophysical Journal, Vol. 805, p. 41.
  45. Gohil, R. & Ballantyne, D.R., 2015, On the equivalent width of the Fe Kα line produced by a dusty absorber in active galactic nuclei, The Monthly Notices of the Royal Astronomical Society, Vol. 449, p. 1449.
  46. Baloković, M., Matt, G., Harrison, F.A., Zoghbi, A., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Craig, W.W., Fabian, A.C., Füerst, F., Hailey, C.J., Marinucci, A., Parker, M.L., Reynolds, C.S., Stern, D., Walton, D.J. & Zhang, W.W., 2015, Coronal Properties of the Seyfert 1.9 Galaxy MCG-5-23-016 Determined from Hard X-ray Spectroscopy with NuSTAR, The Astrophysical Journal, Vol. 800, p. 62.
  47. Matt, G., Baloković, M., Marinucci, A., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Comastri, A., Craig, W.W., Gandhi, P., Hailey, C.J., Harrison, F.A., Madejski, G., Stern, D. & Zhang, W.W., 2015, The hard X-ray spectrum of NGC 5506 as seen by NuSTAR, The Monthly Notices of the Royal Astronomical Society, Vol. 447, p. 3029.
  48. Marinucci, A., Matt, G., Bianchi, S., Lu, T.N., Arevalo, P., Baloković, M., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Christensen, F.E., Craig, W.W., Gandhi, P., Hailey, C.J., Harrison, F., Puccetti, S., Rivers, E., Walton, D.J., Stern, D. & Zhang, W., 2015, The Seyfert 2 galaxy NGC 2110: hard X-ray emission observed by NuSTAR and variability of the iron Kα line, The Monthly Notices of the Royal Astronomical Society, Vol. 447, p. 160.
  49. Keek, L., Ballantyne, D.R., Kuulkers, E. & Strohmayer, T.E., 2014, X-raying an Accretion Disk in Realtime: The Evolution of Ionized Reflection During a Superburst from 4U 1636-536, The Astrophysical Journal, Vol. 797, p. L23.
  50. Stern, D. Lansbury, G.B., Assef, R.J., Brandt, W.N., Alexander, D.M., Ballantyne, D.R., Baloković, M., Benford, D., Blain, A., Boggs, S.E., Bridge, C., Brightman, M., Christensen, F.E., Comastri, A., Craig, W.W., Del Moro, A., Eisenhardt, P.R.M., Gandhi, P., Griffith, R., Hailey, C.J., Harrison, F.A., Hickox, R.C., Jarret, T.H., Koss, M., Lake, S., LaMassa, S.M., Luo, B., Tsai, C.-W., Walton, D.J., Wright, E.L., Wu, J., Yan, L., & Zhang, W.W., 2014, NuSTAR and XMM-Newton Observations of Luminous, Heavily Obscured, WISE-Selected Quasars at z~2, The Astrophysical Journal, Vol. 794, p. 102.
  51. Baloković, M., Comastri, A., Harrison, F.A., Ballantyne, D.R., Boggs, S.E., Brandt, W.N., Brightman, M., Christensen, F.E., Craig, W.W., Del Moro, A., Gandhi, P., Hailey, C.J., Koss, M., Lansbury, G.B., Luo, B., Madejski, G.M., Marinucci, A., Markwardt, C.B., Reynolds, C.S., Risaliti, G., Rivers, E., Stern, D., Walton, D.J., Zhang, W.W., 2014, The NuSTAR View of Nearby Compton-Thick AGN: The Cases of NGC 424, NGC 1320 and IC 2560, The Astrophysical Journal, Vol. 794, p. 111.
  52. Ballantyne, D.R., Bollenbacher, J.M., Brenneman, L.W., Madsen, K.K., Baloković, M., Boggs, S.E., Christensen, F.E., Craig, W.W., Gandhi, P., Hailey, C.J., Harrison, F.A., Lohfink, A.M., Marinucci, A.., Markwardt, C.B., Stern, D., Walton, D.J. & Zhang, W.W., 2014, NuSTAR Reveals the Comptonizing Corona of the Broad-Line Radio Galaxy 3C 382, The Astrophysical Journal, Vol. 794, p. 62.
  53. Gandhi, P., Lansbury, G.B., Alexander, D.M., Stern, D., Arévalo, P., Ballantyne, D.R., Baolković, M., Bauer, F.E., Boggs, S.E., Brandt, W.N., Brightman, M.R., Christensen, F.E., Comastri, A., Craig, W.E., Del Moro, A., Elvis, M., Fabian, A.C., Hailey, C.J., Harrison, F.A., Hickox, R.C., Koss, M.R., LaMassa, S.M., Luo, B., Madejski, G.M., Ptak, A.F., Puccetti, S., Teng, S.H., Urry, C.M., Walton, D.J. & Zhang, W.W., 2014, NuSTAR Unveils a Compton-thick Type 2 Quasar in Mrk 34, The Astrophysical Journal, Vol. 792, p. 117.
  54. Keek, L., Ballantyne, D.R., Kuulkers, E. & Strohmayer, T.E., 2014, Characterizing the Evolving X-ray Spectral Features During a Superburst from 4U 1636-536, The Astrophysical Journal, Vol. 789, p. 121.
  55. Brenneman, L.W., Madejski, G., Fuerst, F., Matt, G., Elvis, M., Harrison, F.A., Ballantyne, D.R., Boggs, S.E., Christensen, F.E., Craig, W.W., Fabian, A.C., Grefenstette, B.W., Hailey, C.J., Madsen, K.K., Marinucci, A., Rivers, E., Stern, D., Walton, D.J. & Zhang, W.W., 2014, The Broad-Band X-ray Spectrum of IC 4329A from a Joint NuSTAR/Suzaku Observation, The Astrophysical Journal, Vol. 788, p. 61.
  56. Walton, D.J., Risaliti, G., Harrison, F.A., Fabian, A.C., Miller, J.M., Arevalo, P., Ballantyne, D.R., Boggs, S.E., Brenneman, L.W., Christensen, F.E., Craig, W.W., Elvis, M., Fuerst, F., Gandhi, P., Grefenstette, B.W., Hailey, C.J.,, Kara, E., Luo, B., Madsen, K.K., Marinucci, A., Matt, G., Parker, M.L., Reynolds, C.S., Rivers, E., Ross, R.R., Stern, D. & Zhang, W., 2014, NuSTAR and XMM­-Newton Observations of NGC 1365: Extreme Absorption Variability and a Constant Inner Accretion Disk, The Astrophysical Journal, Vol. 788, p. 76.
  57. Marinucci, A., Matt, G., Miniutti, G., Guainazzi, M., Parker, M.L., Brenneman, L., Fabian, A.C., Kara, E., Arevalo, P., Ballantyne, D.R., Boggs, S.E., Cappi, M., Christensen, F.E., Craig, W.W., Elvis, M., Hailey, C.J., Harrison, F.A., Reynolds, C.S., Risaliti, G., Stern, D.K., Walton, D.J. & Zhang, W., 2014, The Broadband Spectral Variaibility of MCG-6-30-15 Observed by NuSTAR and XMM-Newton, The Astrophysical Journal, Vol. 787, p. 83.
  58. Del Moro, A., Mullaney, J.R., Alexander, D.M., Comastri, A., Bauer, F.E., Treister, E., Stern, D., Civano, F., Ranalli, P., Vignali, C., Aird, J.A., Ballantyne, D.R., Baloković, M., Boggs, S.E., Brandt, W.N., Christensen, F.E., Craig, W.W., Gandhi, P., Gilli, R., Hailey, C.J., Harrison, F.A., Hickox, R.C., LaMassa, S.M., Lansbury, G.B., Luo, B., Puccetti, S., Urry, C.M. & Zhang, W.W., 2014, NuSTAR J0332-2-2746.8: Direct Constraints on the Compton Reflection in a Heavily Obscured Quasar at z ≈ 2, The Astrophysical Journal, Vol. 786, p. 16.
  59. Marinucci, A., Matt, G., Kara, E., Miniutti, G., Elvis, M., Arevalo, P., Ballantyne, D.R., Baloković, M., Bauer, F., Brenneman, L., Boggs, S.E., Cappi, M., Christensen, F.E., Craig, W.W., Fabian, A.C., Fuerst, F., Hailey, C.J., Harrison, F.A., Risaliti, G., Reynolds, C.S., Stern, D.K., Walton, D.J. & Zhang, W., 2014, Simultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the Narrow Line Seyfert 1 galaxy SWIFT J2127.4+5654, Monthly Notices of the Royal Astronomical Society, Vol. 440, p. 2347.
  60. Lansbury, G.B., Alexander, D.M., Del Moro, A., Gandhi, P., Assef, R.J., Stern, D., Aird, J., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Christensen, F.E., Craig, W.W., Elvis, M., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Hickox, R.C., Koss, M., LaMassa, S.M., Luo, B., Mullaney, J.R., Teng, S.H., Urry, C.M. & Zhang, W.W., 2014, NuSTAR Observations of Heavily Obscured Quasars at z~0.5, The Astrophysical Journal, Vol., 785, p. 17.
  61. Brenneman, L., Madejski, G., Fuerst, F., Matt, G., Elvis, M., Harrison, F.A., Ballantyne, D., Boggs, S., Christensen, F., Craig, W., Fabian, A.C., Grefenstette, B., Hailey, C., Madsen, K., Marinucci, A., Rivers, E., Stern, D., Walton, D. & Zhang, W., 2014, Measuring the Coronal Properties of IC 4329A with NuSTAR, The Astrophysical Journal, Vol. 781, p. 83.
  62. Grissom, R.L., Ballantyne, D.R. & Wise, J.H., 2014, On the Contribution of Active Galactic Nuclei to Reionization, Astronomy & Astrophysics, Vol. 561, p. A90.
  63. Ballantyne, D.R., 2014, The average 0.5-200 keV spectrum of local active galactic nuclei and a new determination of the 2-10 keV luminosity function at z≈0, The Monthly Notices of the Royal Astronomical Society, Vol., 437, p. 2845.
  64. La Massa, S.M., Urry, C.M., Cappelluti, N., Civano, F., Ranalli, P., Glikman, E., Treister, E., Richards, G., Ballantyne, D., Stern, D., Cardamone, C., Schawinski, K., Böhringer, H., Chon, G., Murray, S.S., Green, P. & Nandra, K., 2013, Finding Rare AGN: XMM- Newton and Chandra Observations of SDSS Stripe 82, The Monthly Notices of the Royal Astronomical Society, Vol. 436, p. 3581.
  65. Alexander, D.M., Stern, D., Del Moro, A., Lansbury, G.B., Assef, R.J., Aird, J., Ajello, M., Ballantyne, D.R., Bauer, F.E., Boggs, S.E., Brandt, W.N., Christensen, F.E., Civano, F., Comastri, A., Craig, W.W., Elvis, M., Grefenstette, B.W., Hailey, C.J., Harrison, F.A., Hickox, R.C., Luo, B., Madsen, K.K., Mullaney, J.R., Perri, M., Puccetti, S., Saez, C., Treister, E., Urry, C.M., Zhang, W.W., Bridge, C.R., Eisenhardt, P.R.M., Gonzalez, A.H., Miller, S.H. & Tsai, C.W., 2013, The NuSTAR Extragalactic Survey: A First Sensitive Look at the High-Energy Cosmic X-ray Background Population, The Astrophysical Journal, Vol. 773, p. 125.
  66. Harrison, F.A., Craig, W.W., Christensen, F.E., Hailey, C.J., Zhang, W.W., Boggs, S.E., Stern, D., Cook, W.R., Forster, K., Giommi, P., Grefenstette, B.W., Kim, Y., Kitaguchi, T., Koglin, J.E., Madsen, K.K., Mao, P.H., Miyasaka, H., Mori, K., Perri, M., Pivovaroff, M.J., Puccetti, S., Rana, V.R., Westergaard, N.J., Willis, J., Zoglauer, A., An, H., Bachetti, M., Barriere, N.M., Bellm, E.C., Bhaloerao, V., Brejnholt, N.F., Fuerst, F., Liebe, C.C., Markwardt, C.B., Nynka, M., Vogel, J.K., Walton, D.J., Wik, D.R., Alexander, D.M., Cominsky, L.R., Hornschemeier, A.E., Hornstrup, A., Kaspi, V.M., Madejski, G.M., Matt, G., Molendi, S., Smith, D.M., Tomsick, J.A., Ajello, M., Ballantyne, D.R., Baloković, M., Barret, D., Bauer, F.E., Blandford, R.D., Brandt, N.W., Brenneman, L.W., Chiang, J., Chakrabarty, D., Chenevez, J., Comastri, A., Elvis, M., Fabian, A.C., Farrah, D., Fryer, C.L., Gotthelf, E.V., Grindlay, J.E., Helfand, D.J., Krivonos, R., Meier, D.L., Miller, J.M., Natalucci, L., Ogle, P., Ofek, E.P., Ptak, A., Reynolds, S.P., Rigby, J.R., Tagliaferri, G., Thosett, S.E., Treister, E. & Urry, C.M., 2013, The Nuclear Spectroscopic Telescope Array (NuSTAR) Mission, The Astrophysical Journal, Vol. 770, p. 103.
  67. in t' Zand, J.J.M., Galloway, D.K., Marshall, H.L., Ballantyne, D.R., Jonker, P.G., Paerels, F.B.S., Palmer, D.M., Patruno, A. & Weinberg, N.N., 2013, A bright thermonuclear X-ray burst simultaneously observed with Chandra and RXTE, Astronomy & Astrophysics, Vol. 553, p. A83.
  68. Ballantyne, D.R., Armour, J.N. & Indergaard, J.. 2013, The Star Formation Laws of Eddington-Limited Star-Forming Disks, The Astrophysical Journal, Vol. 765, p. 138.
  69. Draper, A.R. & Ballantyne, D.R., 2012, The Merger-Triggered Active Galactic Nucleus Contribution to the Ultraluminous Infrared Galaxy Population, The Astrophysical Journal, Vol. 753, p. L37.
  70. Armour, J.N. & Ballantyne, D.R., 2012, CO Line Emission from Compact Nuclear Starburst Disks Around Active Galactic Nuclei, The Astrophysical Journal, Vol. 752, p. 87.
  71. Draper, A.R. & Ballantyne, D.R., 2012, A Tale of Two Populations: The Contribution of Merger and Secular Processes to the Evolution of Active Galactic Nuclei, The Astrophysical Journal, Vol. 751, p. 72.
  72. Ballantyne, D.R., Purvis, J.D., Strausbaugh, R.G. & Hickox, R.C., 2012, Ionized Reflection Spectra from Accretion Disks Illuminated by X-ray Pulsars, The Astrophysical Journal, Vol. 747, p. L35.
  73. Pierce, C.M., Ballantyne, D.R. & Ivison, R.J., 2011, Evidence for Moderate Star Formation Rates in the Host Galaxies of Active Galactic Nuclei at z < 1, The Astrophysical Journal, Vol. 742, p. 45.
  74. Draper, A.R., Northcott, S. & Ballantyne, D.R., 2011, Are Active Galactic Nuclei the Solution to the Excess Cosmic Radio Background at 1.4 GHz?, The Astrophysical Journal, Vol. 741, p. L39.
  75. Draper, A.R. & Ballantyne, D.R., 2011, The Young, the Old, and the Dusty: Stellar Populations of AGN Hosts, The Astrophysical Journal, Vol. 740, p. 57.
  76. Ballantyne, D.R., Draper, A.R., Madsen, K.K., Rigby, J.R. & Treister, E., 2011, Lifting the Veil on Obscured Accretion: Active Galactic Nuclei Number Counts and Survey Strategies for Imaging Hard X-ray Missions, The Astrophysical Journal, Vol. 736, p. 56.
  77. Ballantyne, D.R., McDuffie, J.R. & Rusin, J.S., 2011, A Correlation Between the Ionization State of the Inner Accretion Disk and the Eddington Ratio of Active Galactic Nuclei, The Astrophysical Journal, Vol. 734, p. 112.
  78. Draper, A.R. & Ballantyne, D.R., 2011, Properties and Expected Number Counts of Active Galactic Nuclei and their Hosts in the Far Infrared, The Astrophysical Journal, Vol. 729, p. 109.
  79.  in t' Zand, J.J.M., Galloway, D.K. & Ballantyne, D.R., 2011, Achromatic latetime variability in thermonuclear X-ray bursts: An accretion disk disrupted by a novalike shell?, Astronomy & Astrophysics, Vol. 525, p. A111.
  80.  Ballantyne, D.R., Schumann, M. & Ford, B., 2011, Modelling the time dependence of the TeV gamma-ray source at the Galactic Centre, Monthly Notices of the Royal Astronomical Society, Vol. 410, p. 1521.
  81.  Cackett, E.M., Miller, J.M., Ballantyne, D.R., Barret, D., Bhattacharyya, S., Boutelier, M., Miller, M.C., Strohmayer, T.E. & Wijnands, R., 2010, Relativistic Lines and Reflection From the Inner Accretion Disks Around Neutron Stars, The Astrophysical Journal, Vol. 720, p. 205.
  82.  D'Ai, A., Di Salvo, T., Ballantyne, D., Iaria, R., Robba. N.R., Papitto, A., Riggio, A., Burderi, L., Piraino, S., Santangelo, A., Matt, G., Dovčiak, M. & Karas, V., 2010, A Self Consistent Approach to the Hard and Soft States of 4U 1705-44, Astronomy & Astrophysics, Vol. 516, p. A36.
  83.  Ballantyne, D.R., 2010, The Integrated Relativistic Iron Line from Active Galactic Nuclei: Chasing the Spin Evolution of Supermassive Black Holes, The Astrophysical Journal, Vol. 716, p. L27.
  84.  Draper, A.R. & Ballantyne, D.R., 2010, The Evolution and Eddington Ratio Distribution of Compton Thick Active Galactic Nuclei, The Astrophysical Journal, Vol. 715, p. L99.
  85.  Ballantyne, D.R., 2010, The Distribution and Cosmic Density of Relativistic Iron Lines in Active Galactic Nuclei, The Astrophysical Journal, Vol. 708, p. L1.
  86. Draper, A.R. & Ballantyne, D.R., 2009, Balancing the Cosmic Energy Budget: The Cosmic X-ray Background, Blazars, and the Compton Thick Active Galactic Nucleus Fraction, The Astrophysical Journal, Vol. 707, p. 778.
  87. Gliozzi, M., Papadakis, I.E., Eracleous, M., Sambruna, R.M., Ballantyne, D.R., Braito, V. & Reeves, J.N., 2009, Short­-term Variability and Power Spectral Density Analysis of the Radio-­Loud Active Galactic Nucleus 3C 390.3, The Astrophysical Journal, Vol. 703, p. 1021.
  88. Sambruna, R.M., Reeves, J.N., Braito, V., Lewis, K.T., Eracleous, M., Gliozzi, M., Tavecchio, F., Ballantyne, D.R., Ogle, P.M., Barth, A.J. & Tueller, J., 2009, Structure of the Accretion Flow in Broad­-Line Radio Galaxies: The Case of 3C 390.3, The Astrophysical Journal, Vol. 700, p. 1473.
  89. Ballantyne, D.R., 2009, The Contribution of Active Galactic Nuclei to the Microjansky Radio Population, The Astrophysical Journal, Vol. 698, p. 1033.