We present the first results from the ongoing, intensive, multiwavelength monitoring program
of the luminous Seyfert 1 galaxy Mrk 817. While this active galactic nucleus was, in part …

We present a new X-ray spectroscopic study of 22 luminous (2× 10 45≲ L bol/erg s− 1≲ 2×
10 46) active galactic nuclei (AGNs) at intermediate redshifts (0.1≲ z≲ 0.4), as part of the …

We present the first results from a 100-day Swift, NICER, and ground-based X-ray–UV–
optical reverberation map** campaign of the Narrow-line Seyfert 1 Mrk 335, when it was …

X-ray observations of active galactic nuclei (AGNs) reveal relativistic reflections from the
innermost regions of accretion disks, which contain general-relativistic footprints caused by …

Abstract The AGN STORM 2 Collaboration targeted the Seyfert 1 galaxy Mrk 817 for a year-
long multiwavelength, coordinated reverberation map** campaign including Hubble …

We present a comprehensive analysis of all XMM–Newton spectra of OJ 287 spanning 15 yr
of X-ray spectroscopy of this bright blazar. We also report the latest results from our …

We examine archival XMM-Newton data on the extremely variable narrow-line Seyfert 1
active galactic nucleus (AGN) 1H 0707-495. We construct fractional excess variance (F var) …

We report on a remarkable change in the spectral energy distribution (SED) of Mrk 841,
providing new insights on how the soft X-ray excess emission in active galactic nuclei …

The relationship between warm absorber (WA) outflows of active galactic nuclei and nuclear
obscuration activities caused by optically thick clouds (obscurers) crossing the line of sight is …

We report the detection of a rapid occultation event in the nearby Seyfert galaxy NGC 6814,
simultaneously captured in a transient light curve and spectral variability. The intensity and …