Re-observing the NLS1 galaxy RE J1034+396 – II. New insights on the soft X-ray excess, QPO, and the analogy with GRS 1915+105 (2020)
Journal Article
Jin, C., Done, C., & Ward, M. (2021). Re-observing the NLS1 galaxy RE J1034+396 – II. New insights on the soft X-ray excess, QPO, and the analogy with GRS 1915+105. Monthly Notices of the Royal Astronomical Society, 500(2), 2475-2495. https://doi.org/10.1093/mnras/staa3386

The active galactic nucleus (AGN) RE J1034+396 displays the most significant X-ray quasi-periodic oscillation (QPO) detected so far. We perform a detailed spectral-timing analysis of our recent simultaneous XMM–Newton, NuSTAR, and Swift observations.... Read More about Re-observing the NLS1 galaxy RE J1034+396 – II. New insights on the soft X-ray excess, QPO, and the analogy with GRS 1915+105.

Broad He i 1.08-µm absorption from the obscurer in the active galaxy NGC 5548 (2020)
Journal Article
Wildy, C., Landt, H., Ward, M. J., Czerny, B., & Kynoch, D. (2021). Broad He i 1.08-µm absorption from the obscurer in the active galaxy NGC 5548. Monthly Notices of the Royal Astronomical Society: Letters, 500(2), 2063-2075. https://doi.org/10.1093/mnras/staa3301

The nucleus of the active galaxy NGC 5548 was the target of two intensive spectroscopic monitoring campaigns at X-ray, ultraviolet (UV), and optical frequencies in 2013/2014. These campaigns detected the presence of a massive obscuration event. In 20... Read More about Broad He i 1.08-µm absorption from the obscurer in the active galaxy NGC 5548.

Geometry of the X-ray source 1H 0707–495 (2020)
Journal Article
Szanecki, M., Niedźwiecki, A., Done, C., Klepczarek, Ł., Lubiński, P., & Mizumoto, M. (2020). Geometry of the X-ray source 1H 0707–495. Astronomy & Astrophysics, 641, Article A89. https://doi.org/10.1051/0004-6361/202038303

Aims. We investigate the constraints on the size and location of the X-ray source in 1H 0707–495 determined from the shape of the relativistically smeared reflection from the accretion disc. Methods. We developed a new code to model an extended X-ray... Read More about Geometry of the X-ray source 1H 0707–495.

Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance (2020)
Journal Article
Ward, M., Done, C., & Jin, C. (2020). Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance. Monthly Notices of the Royal Astronomical Society, 495(4), 3538-3550. https://doi.org/10.1093/mnras/staa1356

RE J1034+396 is a narrow-line Seyfert 1 galaxy (NLS1) in which the first significant X-ray quasi-periodic oscillation (QPO) in an active galactic nucleus (AGN) was observed in 2007. We report the detection of this QPO in a recent XMM–Newton observati... Read More about Reobserving the NLS1 galaxy RE J1034+396 – I. The long-term, recurrent X-ray QPO with a high significance.

State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations (2020)
Journal Article
Ward, M. J., Landt, H., Jin, C., Done, C., & Ferland, G. J. (2020). State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations. Monthly Notices of the Royal Astronomical Society, 494(4), 5917-5922. https://doi.org/10.1093/mnras/staa1207

The great power offered by photoionization models of Active Galactic Nuclei (AGN) emission line regions has long been mitigated by the fact that very little is known about the spectral energy distribution (SED) between the Lyman limit, where interven... Read More about State-of-the-art AGN SEDs for Photoionization Models: BLR Predictions Confront the Observations.

The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star” (2020)
Journal Article
Villarroel, B., Soodla, J., Comerón, S., Mattsson, L., Pelckmans, K., López-Corredoira, M., …Ward, M. J. (2020). The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star”. Astronomical Journal, 159(1), Article 8. https://doi.org/10.3847/1538-3881/ab570f

In this paper we report the current status of a new research program. The primary goal of the "Vanishing and Appearing Sources during a Century of Observations" project is to search for vanishing and appearing sources using existing survey data to fi... Read More about The Vanishing and Appearing Sources during a Century of Observations Project. I. USNO Objects Missing in Modern Sky Surveys and Follow-up Observations of a “Missing Star”.