My Research...

My research focuses on timing analysis of accreting black holes. I use novel techniques to understand the variable signals we observe with multi-wavelength telescopes. In particular, I use X-ray reverberation and quasi-periodic oscillations (QPOs) to study the inner accretion flow. Full CV here.

I'm a member of the STRONGGRAVITY consortium, an EU funded space research project. 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.

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)

Recent Publications

Full ADS search, Refereed journal ADS search

  1. (19) The response of relativistic outflowing gas to the inner accretion disk of a black hole (arXiv, ADS)
  2. 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
  3. (18) From ultraluminous X-ray sources to ultraluminous supersoft sources: NGC 55 ULX, the missing link (arXiv, ADS)
  4. Pinto, Alston, Soria, Middleton, Walton, Sutton, Fabian, Earnshaw, Urquhart, Kara, Roberts, 2017, MNRAS, in press
  5. (17) The Future of X-ray Reverberation from AGN (arXiv, ADS)
  6. A.C. Fabian, W.N. Alston, E.M. Cackett, E.Kara, P.Uttley & D.R. Wilkins, 2016, Astro. Nach., in press
  7. (16) Ultraviolet and X-ray variability of active galactic nuclei with Swift (arXiv, ADS)
  8. Buisson, Lohfink, Alston & Fabian, 2016, MNRAS, 464, 3194
  9. (15) False periodicities in quasar time-domain surveys (arXiv, ADS)
  10. Vaughan, Uttley, Markowitz, Huppenkothen, Middleton, Alston, Scargle & Farr, 2016, MNRAS, 461, 3145
  11. (14) A global look at X-ray time lags in Seyfert Galaxies (arXiv, ADS)
  12. Kara, Alston, Fabian, Cackett, Uttley, Reynolds & Zoghbi, 2016, MNRAS, 462, 511
  13. (13) Quasi periodic oscillations in active galactic nuclei (arXiv, ADS)
  14.  Alston, Fabian, Markeviciute, Parker, Middleton & Kara, 2016, Astro. Nach., 337, 417
  15. (12) A global look at X-ray time lags in Seyfert Galaxies (arXiv, ADS)
  16. Kara, Alston & Fabian, 2016, Astro. Nach., 337, 473
  17. (11) The Rhythm of Fairall 9. I. Observing the Spectral Variability with XMM-Newton and NuSTAR (arXiv, ADS)
  18. Lohfink, Reynolds, Pinto, Alston, Boggs, Christensen, Craig, Fabian, Hailey, Harrison, Kara, Matt, Parker, Stern, Walton & Zhang, 2016, ApJ, 821, 11
  19. (10) NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk (arXiv, ADS)
  20.  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
  21. (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)
  22.  Alston, Parker, Markeviciute, Fabian, Middleton, Lohfink, Kara & Pinto, 2015, MNRAS, 449, 467
  23. (8) Revealing the X-ray variability of AGN with principal component analysis (arXiv, ADS)
  24.  Parker, Fabian, Matt, Koljonen, Kara, Alston, Walton, Marinucci, Brenneman & Risaliti, 2015, MNRAS, 447, 72
  25. (7) X-ray time delays from the Seyfert 2 galaxy IRAS 18325-5926 (arXiv, ADS)
  26.  Lobban, Alston & Vaughan, 2014, MNRAS, 445, 3229
  27. (6) Detection of a QPO in five XMM-Newton observations of RE J1034+396 (arXiv, ADS)
  28.  Alston, Markevičiūtė, Kara, Fabian & Middleton, 2014, MNRAS, 445, 16
  29. (5) The changing X-ray time lag in MCG-6-30-15 (arXiv, ADS)
  30.  Kara, Fabian, Marinucci, Matt, Parker, Alston, Brenneman, Cackett & Miniutti, 2014, MNRAS, 445, 56
  31. (4) A non-thermal study of the brightest cluster galaxy NGC 1275 - the Gamma-Radio connection over four decades (arXiv, ADS)
  32.  Dutson, Edge, Hinton, Hogan, Gurwell & Alston, 2014, MNRAS, 442, 2048
  33. (3) X-ray time delays in the narrow line Seyfert 1 galaxy PG 1244+026 (arXiv, ADS)
  34.  Alston, Done & Vaughan, 2014, MNRAS, 439, 1548
  35. (2) The flux-dependent X-ray time lags in NGC 4051 (arXiv, ADS)
  36.  Alston, Vaughan & Uttley, 2013, MNRAS, 435, 1511
  37. (1) Ultraviolet and X-ray variability of NGC 4051 over 45 days with XMM-Newton and Swift (arXiv, ADS)
  38.  Alston, Vaughan & Uttley, 2013, MNRAS, 429, 75

Telescope Time Awarded

Accepted multi-wavelength telescope proposals:

  1. XMM-Newton, AO15, 250 ks, PI Parker
  2. Understanding the origin of variability in IRAS 13349+2438
  3. XMM-Newton, DDT (AO14), 100 ks, PI Alston
  4. Understanding the X-ray QPO in the active galaxy MS 22549-3712
  5. XMM-Newton, AO14, 120 ks, PI Kara
  6. Reverberation in the bright NLS1, IGR J19378-0617
  7. Liverpool Telescope, Sem15A, 31 hrs, PI Alston
  8. Reverberation mass mapping the central black hole in RE J1034+396
  9. XMM-Newton, AO13, 610 ks (large program), PI Alston (ADS)
  10. Understanding the X-ray Time delays in the simple spectrum NLS1: PG 1244+026
  11. XMM-Newton, AO12, 200 ks, PI Lobban (ADS)
  12. IRAS 18325-5926: A Seyfert 2 displaying unusual spectral characteristics

Curriculum Vitae

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