Outputs (356)

HYPerluminous quasars at the Epoch of ReionizatION (HYPERION): A new regime for the X-ray nuclear properties of the first quasars (2023)
Journal Article
Zappacosta, L., Piconcelli, E., Fiore, F., Saccheo, I., Valiante, R., Vignali, C., …Vanzella, E. (2023). HYPerluminous quasars at the Epoch of ReionizatION (HYPERION): A new regime for the X-ray nuclear properties of the first quasars. Astronomy & Astrophysics, 678, Article A201. https://doi.org/10.1051/0004-6361/202346795

The existence of luminous quasars (QSOs) at the epoch of reionization (EoR; i.e., z > 6) powered by well-grown supermassive black holes (SMBHs) with masses ≳109 M⊙ challenges models of early SMBH formation and growth. To shed light on the nature of t... Read More about HYPerluminous quasars at the Epoch of ReionizatION (HYPERION): A new regime for the X-ray nuclear properties of the first quasars.

Wavelength dependences of the optical/UV and X-ray luminosity correlations of quasars (2023)
Journal Article
Ward, M., Done, C., Jin, C., Lusso, E., & Middei, R. (2024). Wavelength dependences of the optical/UV and X-ray luminosity correlations of quasars. Monthly Notices of the Royal Astronomical Society, 527(1), 356–373. https://doi.org/10.1093/mnras/stad3193

The interband correlations between optical/ultraviolet (UV) and X-ray luminosities of active galactic nuclei (AGNs) are important
for understanding the disc–coronal connection, as well as using AGN as standard candles for cosmology. It is convention... Read More about Wavelength dependences of the optical/UV and X-ray luminosity correlations of quasars.

Estimating black hole spin from AGN SED fitting: the impact of general-relativistic ray tracing (2023)
Journal Article
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

Accretion disc model fitting to optical/UV quasar spectra requires that the highest mass black holes have the highest spin, with implications on the hierarchical growth of supermassive black holes and their host galaxies over cosmic time. However, th... Read More about Estimating black hole spin from AGN SED fitting: the impact of general-relativistic ray tracing.

The origin of long soft lags and the nature of the hard-intermediate state in black hole binaries (2023)
Journal Article
Kawamura, T., Done, C., & Takahashi, T. (2023). The origin of long soft lags and the nature of the hard-intermediate state in black hole binaries. Monthly Notices of the Royal Astronomical Society, 525(1), 1280-1287. https://doi.org/10.1093/mnras/stad2338

Fast variability of the X-ray corona in black hole binaries can produce a soft lag by reverberation, where the reprocessed thermalized disc photons lag behind the illuminating hard X-rays. This lag is small, and systematically decreases with increasi... Read More about The origin of long soft lags and the nature of the hard-intermediate state in black hole binaries.

The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc (2023)
Journal Article
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

We use the SOUX sample of ∼700 active galactic nucleus (AGN) to form average optical-ultraviolet (UV)-X-rays spectral energy distributions (SEDs) on a two-dimensional (2D) grid of MBH and L2500. We compare these with the predictions of a new AGN SED... Read More about The SOUX AGN sample: optical/UV/X-ray SEDs and the nature of the disc.

A different view of wind in X-ray binaries: the accretion disc corona source 2S 0921-630 (2023)
Journal Article
Tomaru, R., Done, C., Odaka, H., & Tanimoto, A. (2023). A different view of wind in X-ray binaries: the accretion disc corona source 2S 0921-630. Monthly Notices of the Royal Astronomical Society, 523(3), 3441-3449. https://doi.org/10.1093/mnras/stad1637

Accretion disc coronae (ADC) sources are very high inclination neutron star or black hole binaries, where the outer accretion flow blocks a direct view of the central source. The weak observed X-ray emission is instead produced mainly by scattering o... Read More about A different view of wind in X-ray binaries: the accretion disc corona source 2S 0921-630.

Tracking the spectral properties of ESO 511-G030 across different epochs (2023)
Journal Article
Middei, R., Petrucci, P., Bianchi, S., Ursini, F., Matzeu, G. A., Vagnetti, F., …Done, C. (2023). Tracking the spectral properties of ESO 511-G030 across different epochs. Astronomy & Astrophysics, 672, 1-17. https://doi.org/10.1051/0004-6361/202244022

The Type 1 active galactic nucleus (AGN) ESO 511-G030, a formerly bright and soft excess dominated source, was observed in 2019 in the context of a multi-wavelength monitoring campaign. In the new exposures, the source was found to be in a flux state... Read More about Tracking the spectral properties of ESO 511-G030 across different epochs.

Modelling continuum reverberation in active galactic nuclei: a spectral-timing analysis of the ultraviolet variability through X-ray reverberation in Fairall 9 (2023)
Journal Article
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

Continuum reverberation mapping of active galactic nuclei (AGNs) can provide new insight into the nature and geometry of the accretion flow. Some of the X-rays from the central corona irradiating the disc are absorbed, increasing the local disc tempe... Read More about Modelling continuum reverberation in active galactic nuclei: a spectral-timing analysis of the ultraviolet variability through X-ray reverberation in Fairall 9.

The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition (2023)
Journal Article
Kynoch, D., Mitchell, J. A. J., Ward, M. J., Done, C., Lusso, E., & Landt, H. (2023). The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition. Monthly Notices of the Royal Astronomical Society, 520(2), 2781-2805. https://doi.org/10.1093/mnras/stad221

We assemble a sample of 696 type 1 active galactic nuclei (AGN) up to a redshift of z = 2.5, all of which have an SDSS spectrum containing at least one broad emission line (H α, H β, or Mg II) and an XMM-Newton X-ray spectrum containing at least 250... Read More about The SOUX AGN sample: SDSS–XMM-Newton optical, ultraviolet, and X-ray selected active galactic nuclei spanning a wide range of parameter space – sample definition.

The radio detection and accretion properties of the peculiar nuclear transient AT 2019avd (2023)
Journal Article
Wang, Y., Baldi, R. D., del Palacio, S., Guolo, M., Yang, X., Zhang, Y., …Dai, L. (2023). The radio detection and accretion properties of the peculiar nuclear transient AT 2019avd. Monthly Notices of the Royal Astronomical Society, 520(2), 2417–2435. https://doi.org/10.1093/mnras/stad101

AT 2019avd is a nuclear transient detected from infrared to soft X-rays, though its nature is yet unclear. The source has shown two consecutive flaring episodes in the optical and the infrared bands, and its second flare was covered by X-ray monitori... Read More about The radio detection and accretion properties of the peculiar nuclear transient AT 2019avd.