Staff profile
Overview
https://www.physics.dur.ac.uk/staffphotos/t_p_roberts.jpg
Prof Tim Roberts
Professor
B.Sc., Ph.D., PG Cert
| Affiliation | Room number | Telephone |
|---|---|---|
| Professor in the Department of Physics | ocw123 | +44 (0) 191 33 43767 |
| Member of the Centre for Extragalactic Astronomy |
Biography
Responsibilities within department
Current: Director of Education;
Previous: Health & Safety committee; Teaching Review committee; Admissions selector; L4 course director; General Problems paper committee chair; Assessment & Feedback Committee; Physics in Society module leader
Teaching activity
Current: L4 Radiative Processes in Astrophysics lecture course; L4 project supervisor.
Previous: L1 Phases of Matter lecture course; L1 Astrobiology lecture course; L1 Thermodynamics lecture course; L1 tutor; L2 tutor; L2 labs; L2 Physics in Society tutor; L3 General Problems class organiser; L3 Planetary Systems lecturer; L4 project moderator; Postgrad lectures on Black Holes.
Research interests
- Ultraluminous X-ray sources
- The X-ray emission of nearby normal galaxies
- Starburst galaxies
- Low-luminosity active galactic nuclei
Research groups
- Astronomy and Astrophysics
- Centre for Extragalactic Astronomy
Awarded Grants
- 2020: RF040659: Astronomy Consolidated Grant 2020-2023 CEA, £2408347.17, 2020-04-01 - 2023-03-31
- 2013: A programme of astronomical instrumentation and high energy astrophysics at Durham 2013-2015(£961829.80 from STFC)
Publications
Journal Article
- Barra, F, Pinto, C, Walton, D J, Kosec, P, D’Aì, A, Di Salvo, T, Del Santo, M, Earnshaw, H, Fabian, A C, Fuerst, F, Marino, A, Pintore, F, Robba, A & Roberts, T P (2022). Unveiling the disc structure in ultraluminous X-ray source NGC 55 ULX-1. Monthly Notices of the Royal Astronomical Society 516(3): 3972-3983.
- Earnshaw, Hannah P., Brightman, Murray, Harrison, Fiona A., Heida, Marianne, Jaodand, Amruta, Middleton, Matthew J., Roberts, Timothy P. & Walton, Dominic J. (2022). The variability behavior of NGC 925 ULX-3. The Astrophysical Journal 934(1): 42.
- Robba, A, Pinto, C, Pintore, F, Rodriguez, G, Ambrosi, E, Barra, F, Cusumano, G, D’Aì, A, Del Santo, M, Kosec, P, Marino, A, Middleton, M, Roberts, T, Salvaggio, C, Soria, R, Wolter, A & Walton, D (2022). A transient ultraluminous X-ray source in NGC 55. Monthly Notices of the Royal Astronomical Society 515(4): 4669–4674.
- Sathyaprakash, R., Roberts, T.P., Grisé, F., Kaaret, P., Ambrosi, E., Done, C., Gladstone, J.C., Kajava, J.J.E. Soria, R. & Zampieri, L. (2022). A multi-wavelength view of distinct accretion regimes in the pulsating ultraluminous X-ray source NGC 1313 X-2. Monthly Notices of the Royal Astronomical Society 511(4): 5346-5362.
- Khan, N., Middleton, M.J., Wiktorowicz, G., Dauser, T., Roberts, T.P. & Wilms, J. (2022). The impact of precession on the observed population of ULXs. Monthly Notices of the Royal Astronomical Society 509(2): 2493-2506.
- Walton, D.J., Mackenzie, A.D.A., Gully, H., Patel, N.R., Roberts, T.P., Earnshaw, H.P. & Mateos, S. (2022). A multi-mission catalogue of Ultraluminous X-ray Source candidates. Monthly Notices of the Royal Astronomical Society
- D'A,ì A., Pinto, C., Del Santo, M., Pintore, F., Soria, R., Robba, A., Ambrosi, E., Alston, W., Barret, D., Fabian, A.C., Fürst, F., Kara, E., Kosec, P., Middleton, M., Roberts, T., Rodriguez-Castillo, G. & Walton, D.J. (2021). The chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1. Monthly Notices of the Royal Astronomical Society 507(4): 5567-5579.
- Robba, A., Pinto, C., Walton, D. J., Soria, R., Kosec, P., Pintore, F., Roberts, T. P., Alston, W. N., Middleton, M., Cusumano, G., Earnshaw, H. P., Fuerst, F., Sathyaprakash, R., Kyritsis, E. & Fabian, A. C. (2021). Broadband X-ray spectral variability of the pulsing ULX NGC 1313 X-2. Astronomy & Astrophysics 652: A118.
- Fuerst, F., Walton, D. J., Heida, M., Bachetti, M., Pinto, C., Middleton, M. J., Brightman, M., Earnshaw, H. P., Barret, D., Fabian, A. C., Kretschmar, P., Pottschmidt, K., Ptak, A., Roberts, T., Stern, D., Webb, N. & Wilms, J. (2021). Long-term pulse period evolution of the ultra-luminous X-ray pulsar NGC 7793 P13. Astronomy & Astrophysics 651: A75.
- Pinto, C., Soria, R., Walton, D., D'Ai, A., Pintore, F., Kosec, P., Alston, W. N., Fuerst, F., Middleton, M. J., Roberts, T. P., Del Santo, M., Barret, D., Ambrosi, E., Robba, A., Earnshaw, H. & Fabian, A. (2021). XMM-Newton campaign on the ultraluminous X-ray source NGC 247 ULX-1: outflows. Monthly Notices of the Royal Astronomical Society 505(4): 5058-5074.
- Alston, W. N., Pinto, C., Barret, D., D'Ai, A., Del Santo, M., Earnshaw, H., Fabian, A. C., Fuerst, F., Kara, E., Kosec, P., Middleton, M. J., Parker, M. L., Pintore, F., Robba, A., Roberts, T. P., Sathyaprakash, R., Walton, D. & Ambrosi, E. (2021). Quasi-periodic dipping in the ultraluminous X-ray source, NGC 247 ULX-1. Monthly Notices of the Royal Astronomical Society 505(3): 3722-3729.
- Walton, D J, Heida, M, Bachetti, M, Fürst, F, Brightman, M, Earnshaw, H, Evans, P A, Fabian, A C, Grefenstette, B W, Harrison, F A, Israel, G L, Lansbury, G B, Middleton, M J, Pike, S, Rana, V, Roberts, T P, Rodriguez Castillo, G A, Salvaterra, R, Song, X & Stern, D (2021). A new transient ultraluminous X-ray source in NGC 7090. Monthly Notices of the Royal Astronomical Society 501(1): 1002-1012.
- López, K.M., Heida, M., Jonker, P.G., Torres, M.A.P., Roberts, T.P., Walton, D.J., Moon, D-S. & Harrison, F. A. (2020). NIR Counterparts to ULXs (III): Completing the photometric survey and selected spectroscopic results*. Monthly Notices of the Royal Astronomical Society 497(1): 917-932.
- Rodríguez Castillo, G. A., Israel, G. L., Belfiore, A., Bernardini, F., Esposito, P., Pintore, F., De Luca, A., Papitto, A., Stella, L., Tiengo, A., Zampieri, L., Bachetti, M., Brightman, M., Casella, P., D’Agostino, D., Dall’Osso, S., Earnshaw, H. P., Fürst, F., Haberl, F., Harrison, F. A., Mapelli, M., Marelli, M., Middleton, M., Pinto, C., Roberts, T. P., Salvaterra, R., Turolla, R., Walton, D. J. & Wolter, A. (2020). Discovery of a 2.8 s Pulsar in a 2 Day Orbit High-mass X-Ray Binary Powering the Ultraluminous X-Ray Source ULX-7 in M51. The Astrophysical Journal 895(1): 60.
- Walton, D.J. Pinto, C., Nowak, M., Bachetti, M., Sathyaprakash, R., Kara, E., Roberts, T.P., Soria, R., Brightman, M., Canizares, C.R., Earnshaw, H.P., Fürst, F., Heida, M., Middleton, M.J., Stern, D., Tao, L., Webb, N., Alston, W.N., Barret, D., Fabian, A.C., Harrison, F.A. & Kosec, P. (2020). The unusual broad-band X-ray spectral variability of NGC 1313 X-1 seen with XMM–Newton, Chandra, and NuSTAR. Monthly Notices of the Royal Astronomical Society 494(4): 6012-6029.
- Earnshaw, Hannah P., Heida, Marianne, Brightman, Murray, Fürst, Felix, Harrison, Fiona A., Jaodand, Amruta, Middleton, Matthew J., Roberts, Timothy P., Sathyaprakash, Rajath, Stern, Daniel & Walton, Dominic J. (2020). The (re)appearance of NGC 925 ULX-3, a new transient ULX. Astrophysical Journal 891(2): 153.
- Pintore, F., Marelli, M., Salvaterra, R., Israel, G. L., Rodríguez Castillo, G. A., Esposito, P., Belfiore, A., De Luca, A., Wolter, A., Mereghetti, S., Stella, L., Rigoselli, M., Earnshaw, H. P., Pinto, C., Roberts, T. P., Walton, D. J., Bernardini, F., Haberl, F., Salvaggio, C., Tiengo, A., Zampieri, L., Bachetti, M., Brightman, M., Casella, P., D'Agostino, D., Dall'Osso, S., Fuerst, F., Harrison, F. A., Mapelli, M., Papitto, A. & Middleton, M. (2020). The Ultraluminous X-ray sources population of the galaxy NGC 7456. Astrophysical Journal 890(2): 166.
- Pinto, C., Mehdipour, M., Walton, D. J., Middleton, M. J., Roberts, T. P., Fabian, A. C., Guainazzi, M., Soria, R., Kosec, P. & Ness, J. -U. (2020). Thermal stability of winds driven by radiation pressure in super-Eddington accretion discs. Monthly Notices of the Royal Astronomical Society 491(4): 5702-5716.
- Kara, E., Pinto, C., Walton, D. J., Alston, W. N., Bachetti, M., Barret, D., Brightman, M., Canizares, C. R., Earnshaw, H. P., Fabian, A. C., Furst, F., Kosec, P., Middleton, M. J., Roberts, T. P., Soria, R., Tao, L. & Webb, N. A. (2020). Discovery of a soft X-ray lag in the Ultraluminous X-ray Source NGC 1313 X-1. Monthly Notices of the Royal Astronomical Society 491(4): 5172-5178.
- Song, X., Walton, D. J., Lansbury, G. B., Evans, P. A., Fabian, A. C., Earnshaw, H. & Roberts, T. P. (2020). The Hunt for Pulsating Ultraluminous X-ray Sources. Monthly Notices of the Royal Astronomical Society 491(1): 1260-1277.
- Pinto, C, Walton, D J, Kara, E, Parker, M L, Soria, R, Kosec, P, Middleton, M J, Alston, W N, Fabian, A C, Guainazzi, M, Roberts, T P, Fuerst, F, Earnshaw, H P, Sathyaprakash, R & Barret, D (2020). XMM–Newton campaign on ultraluminous X-ray source NGC 1313 X-1: wind versus state variability. Monthly Notices of the Royal Astronomical Society 492(4): 4646-4665.
- López, K M, Jonker, P G, Heida, M, Torres, M A P, Roberts, T P, Walton, D J, Moon, D-S & Harrison, F A (2019). Discovery and analysis of a ULX nebula in NGC 3521★. Monthly Notices of the Royal Astronomical Society 489(1): 1249-1264.
- Sathyaprakash, R., Roberts, T.P. & Siwek, M. (2019). Observational limits on the X-ray emission from the bubble nebula surrounding Ho IX X-1. Monthly Notices of the Royal Astronomical Society 488(4): 4614-4622.
- Middleton, M., Fragile, P.C., Ingram, A. & Roberts, T.P. (2019). The Lense-Thirring timing-accretion plane for ULXs. Monthly Notices of the Royal Astronomical Society 489(1): 282-296.
- Sathyaprakash, R., Roberts, T.P., Walton, D.J., Fuerst, F., Bachetti, M., Pinto, C., Alston, W.N., Earnshaw, H.P., Fabian, A.C., Middleton, M.J. & Soria, R. (2019). The discovery of weak coherent pulsations in the ultraluminous X-ray source NGC 1313 X-2. Monthly Notices of the Royal Astronomical Society Letters 488(1): L35–L40.
- Anderson, G. E., Miller-Jones, J. C. A., Middleton, M. J., Soria, R., Swartz, D. A., Urquhart, R., Hurley-Walker, N., Hancock, P. J., Fender, R. P., Gandhi, P., Markoff, S. & Roberts, T. P. (2019). Discovery of a radio transient in M81. Monthly Notices of the Royal Astronomical Society 489(1): 1181-1196.
- Earnshaw, H.P., Roberts, T.P., Middleton, M.J., Walton, D.J. & Mateos, S (2019). A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies. Monthly Notices of the Royal Astronomical Society 483(4): 5554–5573.
- Brightman, M., Baloković, M., Koss, M., Alexander, D. M., Annuar, A., Earnshaw, H., Gandhi, P., Harrison, F. A., Hornschemeier, A. E., Lehmer, B., Powell, M. C., Ptak, A., Rangelov, B., Roberts, T. P., Stern, D., Walton, D. J. & Zezas, A. (2018). A long hard-X-ray look at the dual active galactic nuclei of M51 with NuSTAR. The Astrophysical Journal 867(2): 110.
- Earnshaw, H.P., Roberts, T.P. & Sathyaprakash, R. (2018). Searching for propeller-phase ULXs in the XMM-Newton Serendipitous Source Catalogue. Monthly Notices of the Royal Astronomical Society 476(3): 4272-4277.
- Middleton, M.J., Fragile, P.C., Bachetti, M., Brightman, M., Jiang, Y-F., Ho, W.G.C., Roberts, T.P., Ingram, A.R., Dauser, T., Pinto, C., Walton, D.J., Fuerst, F., Fabian, A.C. & Gehrels, N. (2018). Lense-Thirring precession in ULXs as a possible means to constrain the neutron star equation-of-state. Monthly Notices of the Royal Astronomical Society 475(1): 154-166.
- Kaaret, Philip, Feng, Hua & Roberts, Timothy P. (2017). Ultraluminous X-Ray Sources. Annual Review of Astronomy and Astrophysics 55(1): 303-341.
- Siwek, M., Sadowski, A., Narayan, R., Roberts, T.P. & Soria, R. (2017). Optical and X-ray luminosity of expanding nebulae around ultraluminous X-ray sources. Monthly Notices of the Royal Astronomical Society 470(1): 361-371.
- López, K.M., Heida, M., Jonker, P.G., Torres, M.A.P., Roberts, T.P., Walton, D.J., Moon, D.-S. & Harrison, F.A. (2017). A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II). Monthly Notices of the Royal Astronomical Society 469(1): 671-682.
- Pinto, C., Alston, W., Soria, R., Middleton, M.J., Walton, D.J., Sutton, A.D., Fabian, A.C., Earnshaw, H., Urquhart, R., Kara, E. & Roberts, T.P. (2017). From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link. Monthly Notices of the Royal Astronomical Society 468(3): 2865-2883.
- Sutton, A. D., Swartz, D. A., Roberts, T. P., Middleton, M. J., Soria, R. & Done, C. (2017). Crossing the Eddington Limit: Examining Disk Spectra at High Accretion Rates. The Astrophysical Journal 836(1): 48.
- Earnshaw, H. M. & Roberts, T. P. (2017). Soft Extragalactic X-Ray Binaries at the Eddington Threshold. Monthly Notices of the Royal Astronomical Society 467(3): 2690-2705.
- Dudik, R. P. Berghea, C. T. Roberts, T. P., Grise, F., Singh, A., Pagano, R. & Winter, L. M. (2016). SPITZER IRAC observations of IR excess in Holmberg IX X-1: A circumbinary disk or a variable jet? The Astrophysical Journal 831(1): 88.
- Walton, D.J., Fürst, F., Bachetti, M., Barret, D., Brightman, M., Fabian, A.C., Gehrels, N., Harrison, F.A., Heida, M., Middleton, M.J., Rana, V., Roberts, T.P., Stern, D., Tao, L. & Webb, N. (2016). A 78 Day X-Ray Period Detected from NGC 5907 ULX1 by Swift. The Astrophysical Journal Letters 827(1): L13.
- Luangtip, W., Roberts, T. P. & Done, C. (2016). The X-ray spectral evolution of the ultraluminous X-ray source Holmberg IX X-1. Monthly Notices of the Royal Astronomical Society 460(4): 4417-4432.
- Roberts, T.P., Middleton, M.J., Sutton, A.D., Mezcua, M., Walton, D.J. & Heil, L.M. (2016). ULX behaviour: The ultraluminous state, winds and interesting anomalies. Astronomische Nachrichten 377(4-5): 534-540.
- Heida, M, Jonker, P. G., Torres, M. A. P., Roberts, T. P., Walton, D. J., Moon, D.-S., Stern, D. & Harrison, F. A. (2016). Keck/MOSFIRE spectroscopy of five ULX counterparts. Monthly Notices of the Royal Astronomical Society 459(1): 771-778.
- Pintore, F., Zampieri, L., Sutton, A. D., Roberts, T. P., Middleton, M. J. & Gladstone, J. C. (2016). The ultraluminous X-ray source NGC 5643 ULX1: a large stellar mass black hole accreting at super-Eddington rates? Monthly Notices of the Royal Astronomical Society 459(1): 455-466.
- Earnshaw, Hannah M., Roberts, Timothy P., Heil, Lucy M., Mezcua, Mar, Walton, Dominic J., Done, Chris, Harrison, Fiona A., Lansbury, George B., Middleton, Matthew J. & Sutton, Andrew D. (2016). A variable ULX and possible IMBH candidate in M51a. Monthly Notices of the Royal Astronomical Society 456(4): 3840-3854.
- Middleton, Matthew J., Walton, Dominic J., Fabian, Andrew, Roberts, Timothy P., Heil, Lucy, Pinto, Ciro, Anderson, Gemma & Sutton, Andrew (2015). Diagnosing the accretion flow in ultraluminous X-ray sources using soft X-ray atomic features. Monthly Notices of the Royal Astronomical Society 454(3): 3134-3142.
- Mezcua, M., Roberts, T. P., Lobanov, A. P. & Sutton, A. D. (2015). The powerful jet of an off-nuclear intermediate-mass black hole in the spiral galaxy NGC 2276. Monthly Notices of the Royal Astronomical Society 448(2): 1893-1899.
- Middleton, M.J., Heil, L., Pintore, F., Walton, D.J. & Roberts, T.P. (2015). A spectral-timing model for ULXs in the supercritical regime. Monthly notices of the Royal Astronomical Society 447(4): 3243-3263.
- Heida, M., Torres, M.A.P., Jonker, P.G., Servillat, M., Repetto, S., Roberts, T.P., Walton, D.J., Moon, D.-S. & Harrison, F.A. (2015). Discovery of a red supergiant counterpart to RX J004722.4-252051, a ULX in NGC 253. Monthly Notices of the Royal Astronomical Society 453(4): 3510-3518.
- Hernández-García, L., Vaughan, S., Roberts, T.P. & Middleton, M. (2015). X-ray time lags and non-linear variability in the ultraluminous X-ray sources NGC 5408 X-1 and NGC 6946 X-1. Monthly Notices of the Royal Astronomical Society 453(3): 2877-2884.
- Walton, D.J., Harrison, F.A., Bachetti, M., Barret, D., Boggs, S.E., Christensen, F.E., Craig, W.W., Fuerst, F., Grefenstette, B.W., Hailey, C.J., Madsen, K.K., Middleton, M.J., Rana, V., Roberts, T.P., Stern, D., Sutton, A.D., Webb, N. & Zhang, W. (2015). NuSTAR and XMM-Newton observations of the extreme ultraluminous X-ray source NGC 5907 ULX1 a vanishing act. Astrophysical journal 799(2): 122.
- Sutton, A. D., Roberts, T. P., Gladstone, J. C. & Walton, D. J. (2015). The hyperluminous X-ray source candidate in IC 4320: another HLX bites the dust. Monthly Notices of the Royal Astronomical Society 450(1): 787-793.
- Sutton, A.D., Roberts, T.P. & Middleton, M.J. (2015). X-ray spectral residuals in NGC 5408 X-1: diffuse emission from star formation, or the signature of a super-Eddington wind? The Astrophysical Journal 814(1): 73.
- Prestwich, A. H., Jackson, F., Kaaret, P., Brorby, M., Roberts, T. P., Saar, S. H. & Yukita, M. (2015). Ultra-luminous X-Ray Sources in HARO II and the Role of X-Ray Binaries in Feedback in Lyα Emitting Galaxies. The Astrophysical Journal 812(2): 166.
- Luangtip, W., Roberts, T.P., Mineo, S., Lehmer, B.D., Alexander, D.M., Jackson, F.E., Goulding, A.D. & Fischer, J.L. (2015). A deficit of ultraluminous X-ray sources in luminous infrared galaxies. Monthly Notices of the Royal Astronomical Society 446(1): 470-492.
- Sutton, Andrew D., Done, Chris & Roberts, Timothy P. (2014). Irradiated, colour-temperature-corrected accretion discs in ultraluminous X-ray sources. Monthly Notices of the Royal Astronomical Society 444(3): 2415-2427.
- Heida, M., Jonker, P.G. Torres, M.A.P. Kool, E. Servillat, M. Roberts, T.P. Groot, P.J. Walton, D.J. Moon, D. & Harrison, F.A. (2014). Near-infrared counterparts of ultraluminous X-ray sources. Monthly Notices of the Royal Astronomical Society 442(2): 1054-1067.
- Middleton, M.J., Walton, D.J., Roberts, T.P. & Heil, L. (2014). Broad absorption features in wind-dominated ultraluminous X-ray sources? Monthly Notices of the Royal Astronomical Society 438(1): L51-L55.
- Mezcua, M., Roberts, T.P., Sutton, A.D. & Lobanov, A.P. (2013). Radio observations of extreme ULXs revealing the most powerful ULX radio nebula ever or the jet of an intermediate-mass black hole? Monthly Notices of the Royal Astronomical Society 436(4): 3128-3134.
- Sutton, A.D., Roberts, T.P., Gladstone, J.C., Farrell, S.A., Reilly, E., Goad, M.R. & Gehrels, N. (2013). A bright ultraluminous X-ray source in NGC 5907. Monthly Notices of the Royal Astronomical Society 434(2): 1702-1712.
- Nebot Gómez-Morán, A., Motch, C., Barcons, X., Carrera, F.J., Ceballos, M.T., Cropper, M., Grosso, N., Guillout, P., Hérent, O., Mateos, S., Michel, L., Osborne, J.P., Pakull, M., Pineau, F.-X., Pye, J.P., Roberts, T.P., Rosen, S.R., Schwope, A.D., Watson, M.G. & Webb, N. (2013). The XMM-Newton SSC survey of the Galactic plane. Astronomy & Astrophysics 553: A12.
- Sutton, A.D., Roberts, T.P. & Middleton, M.J. (2013). The ultraluminous state revisited fractional variability and spectral shape as diagnostics of super-Eddington accretion. Monthly Notices of the Royal Astronomical Society 435(2): 1758-1775.
- Walton, D.J., Miller, J.M., Harrison, F.A., Fabian, A.C., Roberts, T.P., Middleton, M.J. & Reis, R.C. (2013). X-Ray Outflows and Super-Eddington Accretion in the Ultraluminous X-Ray Source Holmberg IX X-1. Astrophysical Journal Letters 773(1): L9.
- Gladstone, J.C., Copperwheat, C., Heinke, C.O., Roberts, T.P., Cartwright, T.F., Levan, A.J. & Goad, M.R. (2013). Optical Counterparts of the Nearest Ultraluminous X-Ray Sources. Astrophysical Journal Supplements 206(2): 14.
- Heida, M., Jonker, P.G., Torres, M.A.P., Roberts, T.P., Miniutti, G., Fabian, A.C. & Ratti, E.M. (2013). VLT/FORS2 observations of four high-luminosity ULX candidates. Monthly Notices of the Royal Astronomical Society 433(1): 681-687.
- Middleton, Matthew J., Miller-Jones, James C. A., Markoff, Sera, Fender, Rob, Henze, Martin, Hurley-Walker, Natasha, Scaife, Anna M. M., Roberts, Timothy P., Walton, Dominic, Carpenter, John, Macquart, Jean-Pierre, Bower, Geoffrey C., Gurwell, Mark, Pietsch, Wolfgang, Haberl, Frank, Harris, Jonathan, Daniel, Michael, Miah, Junayd, Done, Chris, Morgan, John S., Dickinson, Hugh, Charles, Phil, Burwitz, Vadim, Della Valle, Massimo, Freyberg, Michael, Greiner, Jochen, Hernanz, Margarita, Hartmann, Dieter H., Hatzidimitriou, Despina, Riffeser, Arno, Sala, Gloria, Seitz, Stella, Reig, Pablo, Rau, Arne, Orio, Marina, Titterington, David & Grainge, Keith (2013). Bright radio emission from an ultraluminous stellar-mass microquasar in M 31. Nature 493(7431): 187-190.
- Prestwich, A.H., Tsantaki, M., Zezas, A., Jackson, F., Roberts, T.P., Foltz, R., Linden, T. & Kalogera, V. (2013). Ultra-luminous X-ray sources in the most metal poor galaxies. Astrophysical Journal 769(2): 92.
- Middleton, M.J., Sutton, A.D., Roberts, T.P., Jackson, F.E. & Done, C. (2012). The missing link: a low mass X-ray binary in M31 seen as an ultraluminous X-ray source. Monthly Notices of the Royal Astronomical Society 420(4): 2969-2977.
- Gruyters, P., Exter, K., Roberts, T. P. & Rappaport, S. (2012). A VLT VIMOS IFU study of the ionisation nebula surrounding the supersoft X-ray source CAL 83. Astronomy & Astrophysics 544: A86.
- Middleton, M.J., Cackett, E.M., Shaw, C., Ramsay, G., Roberts, T.P. & Wheatley, P.J. (2012). Identifying a new intermediate polar using XMM-Newton and INTEGRAL. Monthly Notices of the Royal Astronomical Society 419(1): 336-341.
- Roberts, T.P., Fabbiano, G., Luo, B., Kim, D.-W., Strader, J., Middleton, M.J., Brodie, J.P., Fragos, T., Gallagher, J.S., Kalogera, V., King, A.R. & Zezas, A. (2012). A variable ultraluminous X-ray source in a globular cluster in NGC 4649. Astrophysical Journal 760(2): 135.
- Prestwich, A.H., Galache, J.L., Linden, T., Kalogera, V., Zezas, A., Roberts, T.P., Kilgard, R., Wolter, A. & Trinchieri, G. (2012). Chandra observations of the collisional ring galaxy NGC 922. The Astrophysical Journal 747(2): 150.
- Sutton, Andrew D., Roberts, Timothy P., Walton, Dominic J., Gladstone, Jeanette C. & Scott, Amy E. (2012). The most extreme ultraluminous X-ray sources: evidence for intermediate-mass black holes? Monthly Notices of the Royal Astronomical Society 423(2): 1154-1177.
- Jonker, P.G., Heida, M., Torres, M.A.P., Miller-Jones, J.C.A., Fabian, A.C., Ratti, E.M., Miniutti, G., Walton, D.J. & Roberts, T.P. (2012). The Nature of the Bright ULX X-2 in NGC 3921: A Chandra Position and HST Candidate Counterpart. Astrophysical Journal 758(1): 28.
- Rasmussen, Jesper, Bai, Xue-Ning, Mulchaey, John S., van Gorkom, J.H., Jeltema, Tesla E., Zabludoff, Ann I., Wilcots, Eric, Martini, Paul, Lee, Duane & Roberts, Timothy P. (2012). Hot and cold galactic gas in the NGC 2563 galaxy group. The Astrophysical Journal 747(1): 31.
- Walton, D.J., Roberts, T.P., Mateos, S. & Heard, V. (2011). 2XMM ultraluminous X-ray source candidates in nearby galaxies. Monthly Notices of the Royal Astronomical Society 416(3): 1844-1861.
- Walton, D.J., Gladstone, J.C., Roberts, T.P., Fabian, A.C., Caballero-Garcia, M.D., Done, C. & Middleton, M.J. (2011). Comparing spectral models for ultraluminous X-ray sources with NGC 4517 ULX1. Monthly Notices of the Royal Astronomical Society 414(2): 1011-1022.
- Middleton, M.J., Roberts, T.P., Done, C. & Jackson, F.E. (2011). Does NGC 5408 X-1 really contain an intermediate-mass black hole? Astronomische Nachrichten 332: 388-391.
- Middleton, M.J., Sutton, A.D. & Roberts, T.P. (2011). X-ray spectral evolution in the ultraluminous X-ray source M33 X-8. Monthly Notices of the Royal Astronomical Society 417(1): 464-471.
- Russell, D.M., Yang, Y.-J., Gladstone, J.C., Wiersema, K. & Roberts, T.P. (2011). New observations of ULX supershells, and their implications. Astronomische Nachrichten 332(4): 371-374.
- Roberts, T.P., Gladstone, J.C., Goulding, A.D., Swinbank, A.M., Ward, M.J., Goad, M.R. & Levan, A.J. (2011). (No) dynamical constraints on the mass of the black hole in two ULXs. Astronomische Nachrichten 332(4): 398-401.
- Jenkins, L.P., Brandt, W.N., Colbert, E.J.M., Koribalski, B., Kuntz, K.D., Levan, A.J., Ojha, R., Roberts, T.P., Ward, M.J. & Zezas, A. (2011). Investigating the Nuclear Activity of Barred Spiral Galaxies: The Case of NGC 1672. Astrophysical Journal 734(1): 33.
- Walton, D.J., Gladstone, J.C., Roberts, T.P. & Fabian A.C. (2011). A large catalogue of ultraluminous X-ray source candidates in nearby galaxies. Astronomische Nachrichten 332(4): 354-357.
- Middleton, M.J., Roberts, T.P., Done, C. & Jackson, F.E. (2011). Challenging times: a re-analysis of NGC 5408 X-1. Monthly Notices of the Royal Astronomical Society 411(1): 644-652.
- Gladstone, J.C., Roberts, T.P. & Done, C. (2011). Unlocking the nature of ultraluminous X-ray sources using their X-ray spectra. Astronomische Nachrichten 332(4): 345-348.
- Sutton, A.D., Roberts, T.P. & Walton, D.J. (2011). Key results from an XMM-Newton and Chandra study of a new sample of extreme ULXs from the 2XMM catalogue. Astronomische Nachrichten 332(4): 362-366.
- Irwin, J.A., Brink, T.G. Bregman, J.N. & Roberts, T.P. (2010). Evidence for a Stellar Disruption by an Intermediate-mass Black Hole in an Extragalactic Globular Cluster. Astrophysical Journal Letters 712(1): L1-L4.
- Vierdayanti, K., Done, C., Roberts, T.P. & Mineshige, S. (2010). X-ray spectral variability in the ultraluminous X-ray source Holmberg IX X-1. Monthly Notices of the Royal Astronomical Society 403(3): 1206-1212.
- Richings, A.J., Fabbiano, G., Wang, J. & Roberts, T.P. (2010). The Hot Interstellar Medium of the Interacting Galaxy NGC 4490. Astrophysical Journal 723: 1375-1392.
- Lehmer, B.D., Alexander, D.M., Bauer, F.E., Brandt, W.N., Goulding, A.D., Jenkins, L.P., Ptak, A. & Roberts, T.P. (2010). A Chandra Perspective on Galaxy-wide X-ray Binary Emission and its Correlation with Star Formation Rate and Stellar Mass: New Results from Luminous Infrared Galaxies. Astrophysical journal 724(1): 559-571.
- Gladstone, J.C., Roberts, T.P. & Done, C. (2009). The ultraluminous state. Monthly Notices of the Royal Astronomical Society 397(4): 1836-1851.
- Gladstone J.C. & Roberts T.P. (2009). The ultraluminous X-ray source population of NGC 4485/4490. Monthly Notices of the Royal Astronomical Society 397(1): 124-134.
- Heil L.M., Vaughan S. & Roberts T.P. (2009). A Systematic Study of Variability in a Sample of Ultraluminous X-ray Sources. Monthly Notices of the Royal Astronomical Society 397(2): 1061-1072.
- Zampieri L. & Roberts T. P. (2009). Low-metallicity natal environments and black hole masses in Ultraluminous X-ray Sources. Monthly Notices of the Royal Astronomical Society 400(2): 677-686.
- Berghea C.T., Weaver K. A., Colbert E. J. M. & Roberts T. P. (2008). Testing the Paradigm that Ultra-Luminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes. Astrophysical Journal 687(1): 471-487.
- Roberts, T. P. Levan, A. J. & Goad, M. R. (2008). New Hubble Space Telescope imaging of the counterparts to six ultraluminous X-ray sources. Monthly Notices of the Royal Astronomical Society 387(1): 73-78.
- Roberts, T.P. (2007). X-ray observations of ultraluminous X-ray sources. Astrophysics and Space Science 311(1-3): 203-212.
- Prestwich, A. H., Kilgard, R., Crowther, P. A., Carpano, S., Pollock, A. M. T., Zezas, A., Saar, S. H., Roberts, T. P. & Ward, M. J. (2007). The Orbital Period of the Wolf-Rayet Binary IC 10 X-1: Dynamic Evidence that the Compact Object Is a Black Hole. Astrophysical Journal 669(1): L21-24.
- Vazquez, G.A., Hornschemeier, A.E., Colbert, E., Roberts, T.P., Ward, M.J. & Malhotra, S. (2007). Constraints on accretion in ultraluminous X-ray sources from Spitzer IRS observations of NGC 4485/4490: Infrared diagnostic diagrams. Astrophysical Journal 658(1): L21-L24.
- Warwick, RS, Jenkins, LP, Read, AM, Roberts, TP & Owen, RA (2007). An XMM-Newton view of M101 - III. Diffuse X-ray emission. Monthly Notices Of The Royal Astronomical Society 376(4): 1611-1620.
- Barcons, X., Carrera, F. J., Ceballos, M. T., Page, M. J., Bussons-Gordo, J., Corral, A., Ebrero, J., Mateos, S., Tedds, J. A., Watson, M. G., Baskill, D., Birkinshaw, M., Boller, T., Borisov, N., Bremer, M., Bromage, G. E., Brunner, H., Caccianiga, A., Crawford, C. S., Cropper, M. S., Della Ceca, R., Derry, P., Fabian, A. C., Guillout, P., Hashimoto, Y., Hasinger, G., Hassall, B. J. M., Lamer, G., Loaring, N. S., Maccacaro, T., Mason, K. O., McMahon, R. G., Mirioni, L., Mittaz, J. P. D., Motch, C., Negueruela, I., Osborne, J. P., Panessa, F., Pérez-Fournon, I., Pye, J. P., Roberts, T. P., Rosen, S., Schartel, N., Schurch, N., Schwope, A., Severgnini, P., Sharp, R., Stewart, G. C., Szokoly, G., Ullán, A., Ward, M. J., Warwick, R. S., Wheatley, P. J., Webb, N. A., Worrall, D., Yuan, W. & Ziaeepour, H. (2007). The XMM-Newton serendipitous survey. IV. Optical identification of the XMM-Newton medium sensitivity survey (XMS). Astronomy and Astrophysics 476(3): 1191-1203.
- Goad, MR, Roberts, TP, Reeves, JN & Uttley, P (2006). A deep XMM-Newton observation of the ultraluminous X-ray source Holmberg II X-1: the case against a 1000-M-circle dot black hole. Monthly Notices Of The Royal Astronomical Society 365(1): 191-198.
- Roberts, T.P., Kilgard, R.E., Warwick, R.S., Goad, M.R. & Ward, M.J. (2006). Chandra monitoring observations of the ultraluminous X-ray source NGC 5204 X-1. Monthly Notices of the Royal Astronomical Society 371(4): 1877-1890.
- Stobbart, AM, Roberts, TP & Warwick, RS (2006). The X-ray properties of the dwarf Magellanic-type galaxy NGC 55. Monthly Notices Of The Royal Astronomical Society 370(1): 25-42.
- Stobbart, A-M., Roberts, T. P. & Wilms, J. (2006). XMM-Newton observations of the brightest ultraluminous X-ray sources. Monthly Notices of the Royal Astronomical Society 368(1): 397-413.
- Roberts, TP, Warwick, RS, Ward, MJ, Goad, MR & Jenkins, LP (2005). XMM-Newton EPIC observations of the ultraluminous X-ray source NGC 5204 X-1. Monthly Notices Of The Royal Astronomical Society 357(4): 1363-1369.
- Krauss, MI, Kilgard, RE, Garcia, MR, Roberts, TP & Prestwich, AH (2005). M74 X-1 (CXOU J013651.1+154547): An extremely variable ultraluminous X-ray source. Astrophysical Journal 630(1): 228-237.
- Jenkins, L. P., Roberts, T. P., Warwick, R. S., Kilgard, R. E. & Ward, M. J. (2005). An XMM-Newton view of M101 - II. Global X-ray source properties. Monthly Notices of the Royal Astronomical Society 357(2): 401-419.
- Watson, MG, Roberts, TP, Akiyama, M & Ueda, Y (2005). Discovery of multiple ultra-luminous X-ray sources in the galaxy KUG 0214-057. Astronomy & Astrophysics 437(3): 899-904.
- Jenkins, LP, Roberts, TP, Ward, MJ & Zezas, A (2005). XMM-Newton observations of the interacting galaxy pairs NGC 7771/0 and NGC 2342/1. Monthly Notices Of The Royal Astronomical Society 357(1): 109-123.
- Jenkins, LP, Roberts, TP, Ward, MJ & Zezas, A (2004). XMM-Newton observations of the starburst merger galaxies NGC 3256 and NGC 3310. Monthly Notices Of The Royal Astronomical Society 352(4): 1335-1346.
- Roberts, T. P., Warwick, R. S., Ward, M. J. & Goad, M. R. (2004). Chandra observations of five ultraluminous X-ray sources in nearby galaxies. Monthly Notices of the Royal Astronomical Society 349(4): 1193-1210.
- Stobbart, AM, Roberts, TP & Warwick, RS (2004). A dipping black hole X-ray binary candidate in NGC 55. Monthly Notices Of The Royal Astronomical Society 351(3): 1063-1070.
- Roberts, TP, Warwick, RS, Ward, MJ & Goad, MR (2004). Chandra observations of five ultraluminous X-ray sources in nearby galaxies (vol 349, pg 1193, 2004). Monthly Notices Of The Royal Astronomical Society 350(4): 1536-1536.
- Jenkins, L. P., Roberts, T. P., Warwick, R. S., Kilgard, R. E. & Ward, M. J. (2004). An XMM-Newton view of M101 - I. The luminous X-ray source population. Monthly Notices of the Royal Astronomical Society 349(2): 404-424.
- Roberts, T. P., Goad, M. R., Ward, M. J. & Warwick, R. S. (2003). The unusual supernova remnant surrounding the ultraluminous X-ray source IC 342 X-1. Monthly Notices of the Royal Astronomical Society 342(3): 709-714.
- Roberts, TP & Colbert, EJM (2003). Chandra reveals a black hole X-ray binary within the ultraluminous supernova remnant MF 16. Monthly Notices Of The Royal Astronomical Society 341(4): L49-L54.
- Roberts, T. P., Warwick, R. S., Ward, M. J. & Murray, S. S. (2002). A Chandra observation of the interacting pair of galaxies NGC 4485/4490. Monthly Notices of the Royal Astronomical Society 337(2): 677-692.
- Barcons, X, Carrera, FJ, Watson, MG, McMahon, RG, Aschenbach, B, Freyberg, MJ, Page, K, Page, MJ, Roberts, TP, Turner, MJL, Barret, D, Brunner, H, Ceballos, MT, Della Ceca, R, Guillout, P, Hasinger, G, Maccacaro, T, Mateos, S, Motch, C, Negueruela, I, Osborne, JP, Perez-Fournon, I, Schwope, A, Severgnini, P, Szokoly, GP, Webb, NA, Wheatley, PJ & Worrall, DM (2002). The XMM-Newton serendipitous survey - II. First results from the AXIS high galactic latitude medium sensitivity survey. Astronomy & Astrophysics 382(2): 522-536.
- Goad, MR, Roberts, TP, Knigge, C & Lira, P (2002). The optical counterpart of the ultraluminous X-ray source NGC 5204 X-1. Monthly Notices Of The Royal Astronomical Society 335(3): L67-L70.
- Schurch, N. J., Roberts, T. P. and Warwick, R. S. (2002). High-resolution X-ray imaging and spectroscopy of the core of NGC 4945 with XMM-Newton and Chandra. Monthly Notices of the Royal Astronomical Society 335: 241-246.
- Watson, MG, Augueres, JL, Ballet, J, Barcons, X, Barret, D, Boer, M, Boller, T, Bromage, GE, Brunner, H, Carrera, FJ, Cropper, MS, Denby, M, Ehle, M, Elvis, M, Fabian, AC, Freyberg, MJ, Guillout, P, Hameury, JM, Hasinger, G, Hinshaw, DA, Maccacaro, T, Mason, KO, McMahon, RG, Michel, L, Mirioni, L, Mittaz, JP, Motch, C, Olive, JF, Osborne, JP, Page, CG, Pakull, M, Perry, BH, Pierre, M, Pietsch, W, Pye, JP, Read, AM, Roberts, TP, Rosen, SR, Sauvageot, JL, Schwope, AD, Sekiguchi, K, Stewart, GC, Stewart, I, Valtchanov, I, Ward, MJ, Warwick, RS, West, RG, White, NE & Worrall, DM (2001). The XMM-Newton serendipitous survey I. The role of XMM-Newton Survey Science Centre. Astronomy And Astrophysics 365(1): L51-L59.
- Pietsch, W, Roberts, TP, Sako, M, Freyberg, MJ, Read, AM, Borozdin, KN, Branduardi-Raymont, G, Cappi, M, Ehle, M, Ferrando, P, Kahn, SM, Ponman, TJ, Ptak, A, Shirey, RE & Ward, M (2001). XMM-Newton observations of NGC 253: Resolving the emission components in the disk and nuclear area. Astronomy And Astrophysics 365(1): L174-L180.
- Roberts, TP, Schurch, NJ & Warwick, RS (2001). Do LINER 2 galaxies harbour low-luminosity active galactic nuclei? Monthly Notices Of The Royal Astronomical Society 324(3): 737-746.
- Roberts, T. P., Goad, M. R., Ward, M. J., Warwick, R. S., O'Brien, P. T., Lira, P. & Hands, A. D. P. (2001). The identification of an optical counterpart to the super-Eddington X-ray source NGC 5204 X-1. Monthly Notices of the Royal Astronomical Society 325(2): L7-L11.
- Roberts, TP & Warwick, RS (2000). A ROSAT High Resolution Imager survey of bright nearby galaxies. Monthly Notices Of The Royal Astronomical Society 315(1): 98-114.
- Hopwood, MEL, Evans, A, Roberts, TP, Burleigh, MR, Odenkirchen, M, Beardmore, AP, O'Brien, T, Jeffries, RD, Penny, A & Eyres, SPS (2000). A possible detection of diffuse extended X-ray emission in the environment of the globular cluster NGC 6779. Monthly Notices Of The Royal Astronomical Society 316(1): L5-L8.
- Roberts, TP, Warwick, RS & Ohashi, T (1999). The X-ray properties of the nearby LINER galaxy NGC 4736. Monthly Notices Of The Royal Astronomical Society 304(1): 52-60.
- Roberts, TP & Warwick, RS (1998). Nuclear X-ray sources in nearby galaxies. Astronomische Nachrichten 319(1-2): 34-34.
- Warwick, RS & Roberts, TP (1998). The extragalactic X-ray background at 0.25 keV. Astronomische Nachrichten 319(1-2): 59-62.
- Barber, CR, Roberts, TP & Warwick, RS (1996). Shadowing of the 0.25-keV extragalactic X-ray background by the disc of NGC 55. Monthly Notices Of The Royal Astronomical Society 282(1): 157-166.
Supervision students
Mr. Duncan Mackenzie
PGR Student