My Research...

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 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. Full CV here.

The blue lightcurve shows the quasi periodic oscillation (QPO) from the supermassive black hole in the centre of the active galaxy RE J1034+396 (see Alston et al 2014). The background image is an artist's impression of the accretion disc and jet around an accreting black hole (credit: NASA/JPL-Caltech)

I'm a former member of the STRONGGRAVITY consortium, an EU funded space research project (FP7/2013-2017). Our aim is to understand the strong gravity produced by black holes across the mass range. Check out our public outreach pages to find out more about black holes - the most extreme objects in our universe - and the methods astronomers use to understand them.

Recent Publications

Full ADS search, Refereed journal ADS search

  1. (28) The discovery of weak coherent pulsations in the ultraluminous X-ray source NGC 1313 X-2 (arXiv, ADS)
  2. Sathyaprakash, Roberts, Walton, Fuerst, Bachetti, Pinto,
    Alston, Earnshaw, Fabian, Middleton & Soria, 2019, MNRAS, 488, 35
  3. (27) Non-stationary variability in accreting compact objects (arXiv, ADS)
  4. Alston, 2019, MNRAS, 485, 260
  5. (26) The remarkable X-ray variability of IRAS 13224--3809 I: the variability process (arXiv, ADS)
  6. 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
  7. (25) NuSTAR reveals the hidden nature of SS433 (arXiv, ADS)
  8. Middleton, Walton, Alston et al, Submitted
  9. (24) A high-density relativistic reflection origin for the soft and hard
    X-ray excess emission from Mrk 1044
    (arXiv, ADS)
  10. Mallick, Alston, Parker, Fabian, Pinto, Dewangan, Markowitz, Gandhi, Kembhavi & Misra, 2018, MNRAS, 479, 615
  11. (23) The 1.5 Ms Observing Campaign on IRAS 13224-3809: X-ray Spectral Analysis I (arXiv, ADS)
  12. Jiang, Parker, Fabian, Alston, Buisson, Cackett, Chiang, Dauser, Gallo, García, Harrison, Lohfink, De Marco, Kara, Miller, Miniutti, Pinto, Walton & Wilkins, 2018, MNRAS, 477, 3711
  13. (22) Ultrafast outflows disappear in high radiation fields (arXiv, ADS)
  14. Pinto, Alston, Parker, Fabian, Gallo, Buisson, Walton, Kara, Jiang, Lohfink & Reynolds, 2018, MNRAS, 476, 1021
  15. (21) Is there a UV/X-ray connection in IRAS 13224-3809? (arXiv, ADS)
  16. Buisson, Lohfink, Alston, Cackett, Chiang, Dauser, De Marco, Fabian, Gallo, García, Jiang, Kara, Middleton, Miniutti, Parker, Pinto, Uttley, Walton & Wilkins, 2018, MNRAS, 475, 2306
  17. (20) Revealing the ultra-fast outflow in IRAS 13224-3809 through spectral variability (arXiv, ADS)
  18. Parker, Alston, Buisson, Fabian, Jiang, Kara, Lohfink, Pinto & Reynolds, 2017, MNRAS, 469, 1553
  19. (19) The response of relativistic outflowing gas to the inner accretion disk of a black hole (arXiv, ADS)
  20. 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
  21. (18) From ultraluminous X-ray sources to ultraluminous supersoft
    sources: NGC 55 ULX, the missing link
    (arXiv, ADS)
  22. Pinto, Alston, Soria, Middleton, Walton, Sutton, Fabian, Earnshaw, Urquhart, Kara & Roberts, 2017, MNRAS, 468, 2865
  23. (17) The Future of X-ray Reverberation from AGN (arXiv, ADS)
  24. Fabian, Alston, Cackett, Kara, Uttley & Wilkins, 2016, Astro. Nach., 338, 269
  25. (16) Ultraviolet and X-ray variability of active galactic nuclei with Swift (arXiv, ADS)
  26. Buisson, Lohfink, Alston & Fabian, 2016, MNRAS, 464, 3194
  27. (15) False periodicities in quasar time-domain surveys (arXiv, ADS)
  28. Vaughan, Uttley, Markowitz, Huppenkothen, Middleton, Alston, Scargle & Farr, 2016, MNRAS, 461, 3145
  29. (14) A global look at X-ray time lags in Seyfert Galaxies (arXiv, ADS)
  30. Kara, Alston, Fabian, Cackett, Uttley, Reynolds & Zoghbi, 2016, MNRAS, 462, 511
  31. (13) Quasi periodic oscillations in active galactic nuclei (arXiv, ADS)
  32.  Alston, Fabian, Markeviciute, Parker, Middleton & Kara, 2016, Astro. Nach., 337, 417
  33. (12) A global look at X-ray time lags in Seyfert Galaxies (arXiv, ADS)
  34. Kara, Alston & Fabian, 2016, Astro. Nach., 337, 473
  35. (11) The Rhythm of Fairall 9. I. Observing the Spectral Variability with XMM-Newton and NuSTAR (arXiv, ADS)
  36. Lohfink, Reynolds, Pinto, Alston, Boggs, Christensen, Craig, Fabian, Hailey, Harrison, Kara,
    Matt, Parker, Stern, Walton & Zhang, 2016, ApJ, 821, 11
  37. (10) NuSTAR and Suzaku observations of the hard state in Cygnus X-1:
    locating the inner accretion disk
    (arXiv, ADS)
  38.  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
  39. (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)
  40.  Alston, Parker, Markeviciute, Fabian, Middleton, Lohfink, Kara & Pinto, 2015, MNRAS, 449, 467
  41. (8) Revealing the X-ray variability of AGN with principal component analysis (arXiv, ADS)
  42.  Parker, Fabian, Matt, Koljonen, Kara, Alston, Walton, Marinucci, Brenneman & Risaliti, 2015, MNRAS, 447, 72
  43. (7) X-ray time delays from the Seyfert 2 galaxy IRAS 18325-5926 (arXiv, ADS)
  44.  Lobban, Alston & Vaughan, 2014, MNRAS, 445, 3229
  45. (6) Detection of a QPO in five XMM-Newton observations of RE J1034+396 (arXiv, ADS)
  46.  Alston, Markevičiūtė, Kara, Fabian & Middleton, 2014, MNRAS, 445, 16
  47. (5) The changing X-ray time lag in MCG-6-30-15 (arXiv, ADS)
  48.  Kara, Fabian, Marinucci, Matt, Parker, Alston, Brenneman, Cackett & Miniutti, 2014, MNRAS, 445, 56
  49. (4) A non-thermal study of the brightest cluster galaxy NGC 1275 - the Gamma-Radio connection
    over four decades
    (arXiv, ADS)
  50.  Dutson, Edge, Hinton, Hogan, Gurwell & Alston, 2014, MNRAS, 442, 2048
  51. (3) X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026 (arXiv, ADS)
  52.  Alston, Done & Vaughan, 2014, MNRAS, 439, 1548
  53. (2) The flux-dependent X-ray time lags in NGC 4051 (arXiv, ADS)
  54.  Alston, Vaughan & Uttley, 2013, MNRAS, 435, 1511
  55. (1) Ultraviolet and X-ray variability of NGC 4051 over 45 days with XMM-Newton and Swift (arXiv, ADS)
  56.  Alston, Vaughan & Uttley, 2013, MNRAS, 429, 75

Curriculum Vitae

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