My research involves the application of novel analysis methods to astronomical data. The main focus is time series analysis of light curves from accreting compact objects (black holes and neutron stars), where the goal is to understand gravity in the strong field regime, extreme physics and the role these objects play in shaping the universe. In particular, I use X-ray reverberation mapping and quasi-periodic oscillations (QPOs) to study matter spiralling in the inner accretion flow around a black hole. I am currently working on neural network methods to find important signals in the presence of red noise.

I've recently hired a graduate to work with me on machine learning applicatiosn to black hole data:

ESA Young Graduate Trainee See advert description here.

Press Releases

Formation of a black hole or neutron star seen for the first time in "The Cow" Nature Astronomy

  • MIT - Super-bright stellar explosion is likely a dying star giving birth to a black hole or neutron star
  • New Scientist - Baffling 'space cow' explosion was a failed supernova

  • Image Credit: Doodle by Victoria Grinberg (ESA)

    Unraveling the inner accretion cone of the microquasar, SS433

  • NASA JPL - Seeing Some Cosmic X-Ray Emitters Might Be a Matter of Perspective

  • Image Credit: NASA/JPL

    X-ray reverberation paper reveals a dynamic black hole corona Nature Astronomy

  • National Geographic - Astronomers just got a deep peek at a black hole
  • European Space Agency (ESA) - XMM-Newton maps black hole surroundings
  • University of Cambridge - Astronomers use ‘cosmic echo-location’ to map black hole surroundings

  • Image Credit: ESA

    Recent Publications

    Full ADS search, Refereed journal ADS search

    1. (49) Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow (arXiv, ADS, Nature Astronomy, Nat. Astron. free access)
    2. Dheeraj R. Pasham, Wynn C. G. Ho, William Alston, Ronald Remillard, Mason Ng, Keith Gendreau, Brian D. Metzger, Diego Altamirano, Deepto Chakrabarty, Andrew Fabian, Jon Miller, Peter Bult, Zaven Arzoumanian, James F. Steiner, Tod Strohmayer, Francesco Tombesi, Jeroen Homan, Edward M. Cackett, Alice Harding 2021, Nat.As tmp,245P
    3. (48) The nature of the extreme X-ray variability in the NLS1 1H 0707-495 (arXiv, ADS)
    4. Parker, Alston, Härer, Igo, Joyce, Buisson, Chainakun, Fabian, Jiang, Kosec, Matzeu, Pinto, Xu, Zaidouni 2021, MNRAS, 508, 1798
    5. (47) The Chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1 (arXiv, ADS)
    6. D'Aì, Pinto, Del Santo, Pintore, Soria, Robba, Ambrosi, Alston, Barret, Fabian, Fürst, Kara, Kosec, Middleton, Roberts, Rodriguez-Castillo, Walton 2021, 507, 5567
    7. (46) NuSTAR reveals the hidden nature of SS433 (arXiv, ADS)
    8. Middleton, Walton, Alston, Dauser, Eikenberry, Jiang, Fabian, Fuerst, Brightman, Marshall, Parker, Pinto, Harrison, Bachetti, Altamirano, Bird, Perez, Miller-Jones, Charles, Boggs, Christensen, Craig, Forster, Grefenstette, Hailey, Madsen, Stern, Zhang 2021, MNRAS, 506, 1045
    9. (45) Quasi-periodic dipping in the ultraluminous X-ray source, NGC 247 ULX-1 (arXiv, ADS)
    10. Alston, Pinto, Barret, D'Ai, Del Santo, Earnshaw, Fabian, Fuerst, Kara, Kosec, Middleton, Parker, Pintore, Robba, Roberts, Sathyaprakash, Walton, Ambrosi 2021, MNRAS, 505, 3722
    11. (44) XMM-Newton campaign on the ultraluminous X-ray source NGC 247 ULX-1: outflows (arXiv, ADS)
    12. Pinto, Soria, Walton, D'Ai, Pintore, Kosec, Alston, Fuerst, Middleton, Roberts, Del Santo, Barret, Ambrosi, Robba, Earnshaw, Fabian 2021, MNRAS, 505, 5058
    13. (43) Extreme relativistic reflection in the active galaxy, ESO 033-G002 (arXiv, ADS)
    14. Walton, Baloković, Fabian, Gallo, Koss, Nardini, Reynolds, Ricci, Stern, Alston, Dauser, García, Kosec, Reynolds, Harrison, Miller 2021, MNRAS, 505, 1557
    15. (42) Broadband X-ray spectral variability of the pulsing ULX NGC 1313 X-2 (arXiv, ADS)
    16. Robba, Pinto, Walton, Soria, Kosec, Pintore, Roberts, Alston, Middleton, Cusumano, Earnshaw, Fuerst, Sathyaprakash, Kyritsis, Fabian 2021, A&A, 652, 118
    17. (41) Modelling the Multiwavelength Variability of Mrk 335 using Gaussian Processes (arXiv, ADS)
    18. Griffiths, Jiang, Buisson, Wilkins, Gallo, Ingram, Lee, Grupe, Kara, Parker, Alston, Bourached, Cann, Young, Komossa 2020, ApJ, 914, 144
    19. (40) Discovery of soft and hard X-ray time lags in low-mass AGNs (arXiv, ADS)
    20. Mallick, Wilkins, Alston, Markowitz, De Marco, Parker, Lohfink, Stalin 2020, MNRAS, 503, 3775
    21. (39) Modelling X-ray RMS spectra II: the ultra-fast outflow of PDS 456 (arXiv, ADS)
    22. Härer, Parker, Joyce, Igo, Alston, Fürst, Lobban, Matzeu, Reeves 2020, MNRAS, 500, 4506
    23. (38) A full characterization of the supermassive black hole in IRAS 09149-6206 (arXiv, ADS)
    24. Walton, Alston, Kosec, Fabian, Gallo, Garcia, Miller, Nardini, Reynolds, Ricci, Stern, Dauser, Harrison, Reynolds 2020, MNRAS, 499, 1480
    25. (37) Detection of a possible multiphase ultra-fast outflow in IRAS 13349+2438 with NuSTAR and XMM-Newton (arXiv, ADS)
    26. Parker, Matzeu, Alston, Fabian, Lobban, Miniutti, Pinto, Santos-Lleó, Schartel, 2020, MNRAS, 498, 140
    27. (36) The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180 (arXiv, ADS)
    28. The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180 Matzeu, Nardini, Parker, Reeves, Braito, Porquet, Middei, Kammoun, Lusso, Alston, Giustini, Lobban, Joyce, Igo, Ebrero, Ballo, Santos-Lleó, Schartel 2020, MNRAS 497, 2352
    29. (35) Characterising continuum variability in the radio-loud narrow-line Seyfert 1
      galaxy IRAS 17020+4544
      (arXiv, ADS)
    30. Gonzalez, Gallo, Kosec, Fabian, Alston, Berton & Wilkins, 2020, MNRAS, 496, 3708
    31. (34) A dynamic black hole corona in an active galaxy through X-ray reverberation mapping (arXiv, ADS, Nature Astronomy, Nat. Astron. free access)
    32. Alston, Fabian, Kara, Parker, Dovciak, Pinto, Jiang, Middleton, Miniutti, Walton, Wilkins, Buisson, Caballero-Garcia, Cackett, De Marco, Gallo, Lohfink, Reynolds, Uttley, Young & Zogbhi, 2020, Nature Astronomy, 4, 597-602
    33. (33) Blueshifted absorption lines from X-ray reflection in IRAS 13224-3809 (arXiv, ADS)
    34. Fabian, Reynolds, Jiang, Pinto, Gallo, Parker, Lasenby, Alston, Buisson, Cackett, De Marco, Garcia, Kara, Kosec, Middleton, Miller, Miniutti, Walton, Wilkins, Young, 2020, MNRAS, 493, 2518
    35. (32) Searching for Ultra-fast Outflows in AGN using Variability Spectra (arXiv, ADS)
    36. Igo, Parker, Matzeu, Alston, Alvarez Crespo, Buisson, Fürst, Joyce, Mallick, Schartel, Santos-Lleó, 2020, MNRAS, 493, 1088
    37. (31) Modelling X-ray RMS spectra I: intrinsically variable AGN (arXiv, ADS)
    38. Parker, Alston, Igo & Fabian 2020, MNRAS, 492, 1363
    39. (30) The Unusual Broadband X-ray Spectral Variability of NGC 1313 X-1 seen with XMM-Newton, Chandra and NuSTAR (arXiv, ADS)
    40. Walton, Pinto, Nowak, Bachetti, Sathyaprakash, Kara, Roberts, Soria, Brightman, Canizares, Earnshaw, Fürst, Heida, Middleton, Stern, Tao, Webb, Alston, Barret, Fabian, Harrison, Kosec, 2020, MNRAS, 494, 6012
    41. (29) XMM-Newton Campaign On Ultraluminous X-ray Source NGC 1313 X-1: Wind vs. State Variability (arXiv, ADS)
    42. Pinto, Walton, Kara, Parker, Soria, Kosec, Middleton, Alston, Fabian, Guainazzi, Roberts, Fuerst, Earnshaw, Sathyaprakash & Barret, 2020, MNRAS, 492, 4646
    43. (28) Discovery of a soft X-ray lag in the Ultraluminous X-ray Source NGC 1313 X-1 (arXiv, ADS)
    44. Kara, Pinto, Walton, Alston, Bachetti, Barret, Brightman, Canizares, Earnshaw, Fabian, Furst, Kosec, Middleton, Roberts, Soria, Tao & Webb, 2020, MNRAS, 491, 5172
    45. (27) The discovery of weak coherent pulsations in the ultraluminous X-ray source NGC 1313 X-2 (arXiv, ADS)
    46. Sathyaprakash, Roberts, Walton, Fuerst, Bachetti, Pinto,
      Alston, Earnshaw, Fabian, Middleton & Soria, 2019, MNRAS, 488, 35
    47. (26) Non-stationary variability in accreting compact objects (arXiv, ADS)
    48. Alston, 2019, MNRAS, 485, 260
    49. (25) The remarkable X-ray variability of IRAS 13224--3809 I: the variability process (arXiv, ADS)
    50. Alston, Fabian, Buisson, Kara, Parker, Lohfink, Uttley, Wilkins, Pinto, De Marco, Cackett, Middleton, Walton, Reynolds, Jiang, Gallo, Zogbhi, Miniutti, Dovciak & Young, 2019, MNRAS, 482, 2088
    51. (24) A high-density relativistic reflection origin for the soft and hard
      X-ray excess emission from Mrk 1044
      (arXiv, ADS)
    52. Mallick, Alston, Parker, Fabian, Pinto, Dewangan, Markowitz, Gandhi, Kembhavi & Misra, 2018, MNRAS, 479, 615
    53. (23) The 1.5 Ms Observing Campaign on IRAS 13224-3809: X-ray Spectral Analysis I (arXiv, ADS)
    54. Jiang, Parker, Fabian, Alston, Buisson, Cackett, Chiang, Dauser, Gallo, García, Harrison, Lohfink, De Marco, Kara, Miller, Miniutti, Pinto, Walton & Wilkins, 2018, MNRAS, 477, 3711
    55. (22) Ultrafast outflows disappear in high radiation fields (arXiv, ADS)
    56. Pinto, Alston, Parker, Fabian, Gallo, Buisson, Walton, Kara, Jiang, Lohfink & Reynolds, 2018, MNRAS, 476, 1021
    57. (21) Is there a UV/X-ray connection in IRAS 13224-3809? (arXiv, ADS)
    58. Buisson, Lohfink, Alston, Cackett, Chiang, Dauser, De Marco, Fabian, Gallo, García, Jiang, Kara, Middleton, Miniutti, Parker, Pinto, Uttley, Walton & Wilkins, 2018, MNRAS, 475, 2306
    59. (20) Revealing the ultra-fast outflow in IRAS 13224-3809 through spectral variability (arXiv, ADS)
    60. Parker, Alston, Buisson, Fabian, Jiang, Kara, Lohfink, Pinto & Reynolds, 2017, MNRAS, 469, 1553
    61. (19) The response of relativistic outflowing gas to the inner accretion disk of a black hole (arXiv, ADS, Nature)
    62. Parker, Pinto, Fabian, Lohfink, Buisson, Alston, Kara, Cackett, Chiang, Dauser, De Marco, Gallo, Garcia, Harrison, King, Middleton, Miller, Miniutti, Reynolds, Uttley, Vasudevan, Walton, Wilkins & Zoghbi, 2017, Nature, 543, 83
    63. (18) From ultraluminous X-ray sources to ultraluminous supersoft
      sources: NGC 55 ULX, the missing link
      (arXiv, ADS)
    64. Pinto, Alston, Soria, Middleton, Walton, Sutton, Fabian, Earnshaw, Urquhart, Kara & Roberts, 2017, MNRAS, 468, 2865
    65. (17) The Future of X-ray Reverberation from AGN (arXiv, ADS)
    66. Fabian, Alston, Cackett, Kara, Uttley & Wilkins, 2016, Astro. Nach., 338, 269
    67. (16) Ultraviolet and X-ray variability of active galactic nuclei with Swift (arXiv, ADS)
    68. Buisson, Lohfink, Alston & Fabian, 2016, MNRAS, 464, 3194
    69. (15) False periodicities in quasar time-domain surveys (arXiv, ADS)
    70. Vaughan, Uttley, Markowitz, Huppenkothen, Middleton, Alston, Scargle & Farr, 2016, MNRAS, 461, 3145
    71. (14) A global look at X-ray time lags in Seyfert Galaxies (arXiv, ADS)
    72. Kara, Alston, Fabian, Cackett, Uttley, Reynolds & Zoghbi, 2016, MNRAS, 462, 511
    73. (13) Quasi periodic oscillations in active galactic nuclei (arXiv, ADS)
    74. Alston, Fabian, Markeviciute, Parker, Middleton & Kara, 2016, Astro. Nach., 337, 417
    75. (12) A global look at X-ray time lags in Seyfert Galaxies (arXiv, ADS)
    76. Kara, Alston & Fabian, 2016, Astro. Nach., 337, 473
    77. (11) The Rhythm of Fairall 9. I. Observing the Spectral Variability with XMM-Newton and NuSTAR (arXiv, ADS)
    78. Lohfink, Reynolds, Pinto, Alston, Boggs, Christensen, Craig, Fabian, Hailey, Harrison, Kara,
      Matt, Parker, Stern, Walton & Zhang, 2016, ApJ, 821, 11
    79. (10) NuSTAR and Suzaku observations of the hard state in Cygnus X-1:
      locating the inner accretion disk
      (arXiv, ADS)
    80. Parker, Tomsick, Miller, Yamaoka, Lohfink, Nowak, Fabian, Alston, Boggs, Christensen, Craig, Fuerst, Gandhi, Grefenstette, Grinberg, Hailey, Harrison, Kara, King, Stern, Walton, Wilms & Zhang, 2015, ApJ, 808, 9
    81. (9) Discovery of a ~2 hr high frequency X-ray QPO and iron K alpha reverberation in
      the active galaxy MS 2254.9-3712
      (arXiv, ADS)
    82. Alston, Parker, Markeviciute, Fabian, Middleton, Lohfink, Kara & Pinto, 2015, MNRAS, 449, 467
    83. (8) Revealing the X-ray variability of AGN with principal component analysis (arXiv, ADS)
    84. Parker, Fabian, Matt, Koljonen, Kara, Alston, Walton, Marinucci, Brenneman & Risaliti, 2015, MNRAS, 447, 72
    85. (7) X-ray time delays from the Seyfert 2 galaxy IRAS 18325-5926 (arXiv, ADS)
    86. Lobban, Alston & Vaughan, 2014, MNRAS, 445, 3229
    87. (6) Detection of a QPO in five XMM-Newton observations of RE J1034+396 (arXiv, ADS)
    88. Alston, Markevičiūtė, Kara, Fabian & Middleton, 2014, MNRAS, 445, 16
    89. (5) The changing X-ray time lag in MCG-6-30-15 (arXiv, ADS)
    90. Kara, Fabian, Marinucci, Matt, Parker, Alston, Brenneman, Cackett & Miniutti, 2014, MNRAS, 445, 56
    91. (4) A non-thermal study of the brightest cluster galaxy NGC 1275 - the Gamma-Radio connection
      over four decades
      (arXiv, ADS)
    92. Dutson, Edge, Hinton, Hogan, Gurwell & Alston, 2014, MNRAS, 442, 2048
    93. (3) X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026 (arXiv, ADS)
    94. Alston, Done & Vaughan, 2014, MNRAS, 439, 1548
    95. (2) The flux-dependent X-ray time lags in NGC 4051 (arXiv, ADS)
    96. Alston, Vaughan & Uttley, 2013, MNRAS, 435, 1511
    97. (1) Ultraviolet and X-ray variability of NGC 4051 over 45 days with XMM-Newton and Swift (arXiv, ADS)
    98. Alston, Vaughan & Uttley, 2013, MNRAS, 429, 75

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