Evolution of thermally driven disk wind in the black hole binary 4U 1630-47 observed with Suzaku and Nustar (2018)
Journal Article
Hori, T., Ueda, Y., Done, C., Shidatsu, M., & Kubota, A. (2018). Evolution of thermally driven disk wind in the black hole binary 4U 1630-47 observed with Suzaku and Nustar. Astrophysical Journal, 869(2), Article 183. https://doi.org/10.3847/1538-4357/aaea5e

We performed simultaneous observations with Suzaku and NuSTAR of the Galactic black hole binary 4U 1630−47 in the high/soft state (HSS) during the 2015 outburst. To compare our results with those observed in the HSS at lower luminosities, we re-analy... Read More about Evolution of thermally driven disk wind in the black hole binary 4U 1630-47 observed with Suzaku and Nustar.

X-ray reverberation lags of the Fe–K line due to AGN disc winds (2018)
Journal Article
Mizumoto, M., Ebisawa, K., Tsujimoto, M., Done, C., Hagino, K., & Odaka, H. (2019). X-ray reverberation lags of the Fe–K line due to AGN disc winds. Monthly Notices of the Royal Astronomical Society, 482(4), 5316-5326. https://doi.org/10.1093/mnras/sty3056

Short X-ray reverberation lags are seen across a broad Fe–K energy band in more than 20 active galactic nuclei (AGNs). This broad iron line feature in the lag spectrum is most significant in super-Eddington sources such as Ark 564 (L/LEdd ∼ 1) and 1H... Read More about X-ray reverberation lags of the Fe–K line due to AGN disc winds.

Evolution of X-ray irradiation during the 1999–2000 outburst of the black hole binary XTE J1859 + 226 (2018)
Journal Article
Kimura, M., & Done, C. (2019). Evolution of X-ray irradiation during the 1999–2000 outburst of the black hole binary XTE J1859 + 226. Monthly Notices of the Royal Astronomical Society, 482(1), 626-638. https://doi.org/10.1093/mnras/sty2736

X-ray irradiation in X-ray binaries is thought to control the behaviour at the outer disc, which is observable mainly at optical wavelengths. It is generally parametrized phenomenologically, but it can also be predicted from theoretical models of irr... Read More about Evolution of X-ray irradiation during the 1999–2000 outburst of the black hole binary XTE J1859 + 226.

A physical model for the spectral-timing properties of accreting black holes (2018)
Journal Article
Mahmoud, R. D., & Done, C. (2018). A physical model for the spectral-timing properties of accreting black holes. Monthly Notices of the Royal Astronomical Society, 480(3), 4040-4059. https://doi.org/10.1093/mnras/sty2133

We develop new techniques to deconvolve the radial structure of the X-ray emission region in the bright low/hard state of the black hole Cygnus X-1 using both spectral and timing data in the 3–35 keV range. The spectrum at these energies is dominated... Read More about A physical model for the spectral-timing properties of accreting black holes.

X-ray/UV/optical variability of NGC 4593 with Swift: reprocessing of X-rays by an extended reprocessor (2018)
Journal Article
McHardy, I., Connolly, S., Horne, K., Cackett, E., Gelbord, J., Peterson, B., …Ward, M. (2018). X-ray/UV/optical variability of NGC 4593 with Swift: reprocessing of X-rays by an extended reprocessor. Monthly Notices of the Royal Astronomical Society, 480(3), 2881-2897. https://doi.org/10.1093/mnras/sty1983

We report the results of intensive X-ray, UV, and optical monitoring of the Seyfert 1 galaxy NGC 4593 with Swift. There is no intrinsic flux-related spectral change in any variable component with small apparent variations being due to contamination b... Read More about X-ray/UV/optical variability of NGC 4593 with Swift: reprocessing of X-rays by an extended reprocessor.

Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop (2018)
Journal Article
Noda, H., & Done, C. (2018). Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop. Monthly Notices of the Royal Astronomical Society, 480(3), 3898-3906. https://doi.org/10.1093/mnras/sty2032

We model the broadband (optical/UV and X-ray) continuum spectrum of the “changing-look” active galactic nucleus (AGN) Mrk 1018 as it fades from Seyfert 1 to 1.9 in ∼8 years. The brightest spectrum, with Eddington ratio L/LEdd ∼ 0.08, has a typical ty... Read More about Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop.

A physical model of the broadband continuum of AGN and its implications for the UV/X relation and optical variability (2018)
Journal Article
Kubota, A., & Done, C. (2018). A physical model of the broadband continuum of AGN and its implications for the UV/X relation and optical variability. Monthly Notices of the Royal Astronomical Society, 480(1), 1247-1262. https://doi.org/10.1093/mnras/sty1890

We develop a new spectral model for the broad-band spectral energy distribution (SED) of active galactic nuclei (AGN). This includes an outer standard disc, an inner warm Comptonizing region to produce the soft X-ray excess and a hot corona. We tie t... Read More about A physical model of the broadband continuum of AGN and its implications for the UV/X relation and optical variability.

Breaking the spectral degeneracies in black hole binaries with fast timing data: the hard state of Cygnus X-1 (2018)
Journal Article
Axelsson, M., & Done, C. (2018). Breaking the spectral degeneracies in black hole binaries with fast timing data: the hard state of Cygnus X-1. Monthly Notices of the Royal Astronomical Society, 480(1), 751-758. https://doi.org/10.1093/mnras/sty1801

The spectra of black hole binaries in the low/hard state are complex, with evidence for multiple different Comptonization regions contributing to the hard X-rays in addition to a cool disc component. We show this explicitly for some of the best RXTE... Read More about Breaking the spectral degeneracies in black hole binaries with fast timing data: the hard state of Cygnus X-1.

X-ray short-time lags in the Fe-K energy band produced by scattering clouds in active galactic nuclei (2018)
Journal Article
Mizumoto, M., Done, C., Hagino, K., Ebisawa, K., Tsujimoto, M., & Odaka, H. (2018). X-ray short-time lags in the Fe-K energy band produced by scattering clouds in active galactic nuclei. Monthly Notices of the Royal Astronomical Society, 478(1), 971-982. https://doi.org/10.1093/mnras/sty1114

X-rays illuminating the accretion disc in active galactic nuclei give rise to an iron K line and its associated reflection spectrum which are lagged behind the continuum variability by the light-travel time from the source to the disc. The measured l... Read More about X-ray short-time lags in the Fe-K energy band produced by scattering clouds in active galactic nuclei.

Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi* (2018)
Journal Article
Collaboration, H., Aharonian, F., Akamatsu, H., Akimoto, F., Allen, S. W., Angelini, L., …Raassen, A. (2018). Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi*. Publications of Astronomical Society of Japan, 70(2), Article 12. https://doi.org/10.1093/pasj/psx156

The Hitomi Soft X-ray Spectrometer spectrum of the Perseus cluster, with ∼5 eV resolution in the 2–9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collisional plasmas. It reveals both successes and challenges... Read More about Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi*.

Hitomi (ASTRO-H) X-ray Astronomy Satellite (2018)
Journal Article
Takahashi, T., Kokubun, M., Mitsuda, K., Kelley, R. L., Ohashi, T., Aharonian, F., …Zoghbi, A. (2018). Hitomi (ASTRO-H) X-ray Astronomy Satellite. Journal of Astronomical Telescopes, Instruments, and Systems, 4(02), Article 021402. https://doi.org/10.1117/1.jatis.4.2.021402

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  > ... Read More about Hitomi (ASTRO-H) X-ray Astronomy Satellite.

Monte-Carlo simulations of the detailed iron absorption line profiles from thermal winds in X-ray binaries (2018)
Journal Article
Tomaru, R., Done, C., Odaka, H., Watanabe, S., & Takahashi, T. (2018). Monte-Carlo simulations of the detailed iron absorption line profiles from thermal winds in X-ray binaries. Monthly Notices of the Royal Astronomical Society, 476(2), 1776-1784. https://doi.org/10.1093/mnras/sty336

Blue–shifted absorption lines from highly ionised iron are seen in some high inclination X-ray binary systems, indicating the presence of an equatorial disc wind. This launch mechanism is under debate, but thermal driving should be ubiquitous. X-ray... Read More about Monte-Carlo simulations of the detailed iron absorption line profiles from thermal winds in X-ray binaries.