Staff profile

• Accretion Physics
• Black Holes
• Spectral Variability

Journal Article

• Systematic collapse of the accretion disc in AGN confirmed by UV photometry and broad-line spectra
  
  Kang, J. L., Done, C., Hagen, S., Temple, M. J., Silverman, J. D., Li, J., & Liu, T. (2025). Systematic collapse of the accretion disc in AGN confirmed by UV photometry and broad-line spectra. Monthly Notices of the Royal Astronomical Society, 538(1), 121-131. https://doi.org/10.1093/mnras/staf145
• Systematic collapse of the accretion disc across the supermassive black hole population
  
  Hagen, S., Done, C., Silverman, J. D., Li, J., Liu, T., Ren, W., Buchner, J., Merloni, A., Nagao, T., & Salvato, M. (2024). Systematic collapse of the accretion disc across the supermassive black hole population. Monthly Notices of the Royal Astronomical Society, 534(3), 2803-2818. https://doi.org/10.1093/mnras/stae2272
• Common origin for black holes in both high mass X-ray binaries and gravitational-wave sources
  
  Belczynski, K., Done, C., Hagen, S., Lasota, J.-P., & Sen, K. (2024). Common origin for black holes in both high mass X-ray binaries and gravitational-wave sources. Astronomy & Astrophysics, 690, Article A21. https://doi.org/10.1051/0004-6361/202450229
• An Eddington-limited Accretion Disk Wind in the Narrow-line Seyfert 1 PG 1448+273
  
  Reeves, J. N., Braito, V., Luminari, A., Porquet, D., Laurenti, M., Matzeu, G., Lobban, A., & Hagen, S. (2024). An Eddington-limited Accretion Disk Wind in the Narrow-line Seyfert 1 PG 1448+273. The Astrophysical Journal, 974(1), Article 58. https://doi.org/10.3847/1538-4357/ad6b95
• Revealing the burning and soft heart of the bright bare active galactic nucleus ESO 141-G55: X-ray broadband and SED analysis
  
  Porquet, D., Reeves, J. N., Hagen, S., Lobban, A., Braito, V., Grosso, N., & Marin, F. (2024). Revealing the burning and soft heart of the bright bare active galactic nucleus ESO 141-G55: X-ray broadband and SED analysis. Astronomy & Astrophysics, 689, Article A336. https://doi.org/10.1051/0004-6361/202449708
• What drives the variability in AGN? Explaining the UV-Xray disconnect through propagating fluctuations
  
  Hagen, S., Done, C., & Edelson, R. (2024). What drives the variability in AGN? Explaining the UV-Xray disconnect through propagating fluctuations. Monthly Notices of the Royal Astronomical Society, 530(4), 4850-4867. https://doi.org/10.1093/mnras/stae1177
• The Peculiar Bursting Nature of CP Pup
  
  Veresvarska, M., Scaringi, S., Hagen, S., De Martino, D., Done, C., Ilkiewicz, K., Knigge, C., & Littlefield, C. (2024). The Peculiar Bursting Nature of CP Pup. Monthly Notices of the Royal Astronomical Society, 529(1), 664-672. https://doi.org/10.1093/mnras/stae573
• Probing the face-on disc-corona system of the bare AGN Mrk 110 from UV to hard X-rays: A moderate changing-state AGN?
  
  Porquet, D., Hagen, S., Grosso, N., Lobban, A., Reeves, J. N., Braito, V., & Done, C. (2024). Probing the face-on disc-corona system of the bare AGN Mrk 110 from UV to hard X-rays: A moderate changing-state AGN?. Astronomy & Astrophysics, 681, Article A40. https://doi.org/10.1051/0004-6361/202347202
• Estimating black hole spin from AGN SED fitting: the impact of general-relativistic ray tracing
  
  Hagen, S., & Done, C. (2023). Estimating black hole spin from AGN SED fitting: the impact of general-relativistic ray tracing. Monthly Notices of the Royal Astronomical Society, 525(3), 3455-3467. https://doi.org/10.1093/mnras/stad2499
• The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc
  
  Mitchell, J. A. J., Done, C., Ward, M. J., Kynoch, D., Hagen, S., Lusso, E., & Landt, H. (2023). The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc. Monthly Notices of the Royal Astronomical Society, 524(2), 1796-1825. https://doi.org/10.1093/mnras/stad1830
• Modelling continuum reverberation in active galactic nuclei: a spectral-timing analysis of the ultraviolet variability through X-ray reverberation in Fairall 9
  
  Hagen, S., & Done, C. (2023). Modelling continuum reverberation in active galactic nuclei: a spectral-timing analysis of the ultraviolet variability through X-ray reverberation in Fairall 9. Monthly Notices of the Royal Astronomical Society, 521(1), 251-268. https://doi.org/10.1093/mnras/stad504