16 papers · 1 filter
Evidence for Millihertz Oscillations in the bright atoll source GX 3+1
Malu Sudha, Renee M. Ludlam, Diego Altamirano +2
We report evidence for millihertz (mHz) QPOs in the bright atoll neutron star low-mass X-ray binary (NS LMXB) source GX 3+1 using NICER in the 0.5--10 keV energy band. Across 7 obs…
The unusually red delay spectrum of the low-mass black hole AGN NGC\,4051 as revealed by intensive continuum reverberation mapping with the Las Cumbres Observatory
Marcin Marculewicz, Juan V. Hernández Santisteban, Keith Horne +12
We present a two-year optical reverberation mapping campaign of NGC 4051, an active galactic nucleus (AGN) hosting a low-mass black hole (), using daily observ…
XRISM/Resolve Spectroscopy of the Central Engine in the Seyfert-1 AGN Mrk 279
Jon M. Miller, Xin Xiang, Doyee Byun +9
High-resolution X-ray spectroscopy with XRISM gives an unprecedented view of the ``central engine'' in active galactic nuclei, providing unique insights into black hole accretion a…
Dual perspectives on GX 17+2: a simultaneous NICER and NuSTAR study
Malu Sudha, Renee M. Ludlam, Jeroen Homan +3
We performed the first simultaneous NICER & NuSTAR spectral and timing study of the Sco-like Z source GX 17+2. The source traced the full Z track during four observations. We detec…
Untangling the Complex Nature of AGN Variability with Fairall 9
Scott Hagen, Chris Done, Edward M. Cackett +5
The accretion flow in AGN is not well understood, motivating intensive monitoring campaigns of multiwavelength variability to probe its structure. One of the best of these is the 3…
The Accretion Disk Size Problem in AGN Disk Reverberation Mapping is an Obscuration Effect: A Uniform AGN Sample Study with Swift
Collin Lewin, Erin Kara, Christos Panagiotou +5
In the past decade, Swift has performed several AGN high-cadence reverberation mapping campaigns, and generally found that the UV/optical interband lags are 3 times longer th…