Dan Wilkins
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View article: A Sharper View of the X-Ray Spectrum of MCG–6-30-15 with XRISM, XMM-Newton, and NuSTAR
A Sharper View of the X-Ray Spectrum of MCG–6-30-15 with XRISM, XMM-Newton, and NuSTAR Open
We present a time-averaged spectral analysis of the 2024 XRISM observation of the narrow-line Seyfert-1 galaxy MCG–6-30-15, taken contemporaneously with XMM-Newton and NuSTAR. Our analysis leverages a unique combination of broadband and hi…
View article: Fast, low noise CCD systems for future strategic x-ray missions
Fast, low noise CCD systems for future strategic x-ray missions Open
Future strategic X-ray missions, such as the Advanced X-ray Imaging Satellite (AXIS) and those targeted by the Great Observatories Maturation Program (GOMaP), require fast, low-noise X-ray imaging spectrometers. To achieve the speed and no…
View article: Ground calibration plans for the AXIS high speed camera
Ground calibration plans for the AXIS high speed camera Open
The Advanced X-ray Imaging Satellite (AXIS), an astrophysics NASA probe mission currently in phase A, will provide high-throughput, high-spatial resolution X-ray imaging in the 0.3 to 10 keV band. We report on the notional ground calibrati…
View article: The high-speed X-ray camera on AXIS: design and performance updates
The high-speed X-ray camera on AXIS: design and performance updates Open
AXIS, a Probe mission concept now in a Phase A study, will provide transformative studies of high-energy astrophysical phenomena thanks to its high-resolution X-ray spectral imaging. These capabilities are enabled by improvements to the mi…
View article: Design, development, and commissioning of a flexible test setup for the AXIS prototype detector
Design, development, and commissioning of a flexible test setup for the AXIS prototype detector Open
The Advanced X-ray Imaging Satellite (AXIS) is one of two candidate mission concepts selected for Phase-A study for the new NASA Astrophysics Probe Explorer (APEX) mission class, with a planned launch in 2032. The X-ray camera for AXIS is …
View article: Development and testing of integrated readout electronics for next generation SiSeRO (Single electron Sensitive Read Out) devices
Development and testing of integrated readout electronics for next generation SiSeRO (Single electron Sensitive Read Out) devices Open
The first generation of Single electron Sensitive Read Out (SiSeRO) amplifiers, employed as on-chip charge detectors for charge-coupled devices (CCDs) have demonstrated excellent noise and spectral performance: a responsivity of around 800…
View article: Variable X-Ray Reverberation in the Rapidly Accreting Active Galactic Nucleus Ark 564: The Response of the Soft Excess to the Changing Geometry of the Inner Accretion Flow
Variable X-Ray Reverberation in the Rapidly Accreting Active Galactic Nucleus Ark 564: The Response of the Soft Excess to the Changing Geometry of the Inner Accretion Flow Open
X-ray reverberation, which exploits the time delays between variability in different energy bands as a function of Fourier frequency, probes the structure of the inner accretion disks and X-ray coronae of active galactic nuclei. We present…
View article: Variable X-ray reverberation in the rapidly accreting AGN Ark 564: the response of the soft excess to the changing geometry of the inner accretion flow
Variable X-ray reverberation in the rapidly accreting AGN Ark 564: the response of the soft excess to the changing geometry of the inner accretion flow Open
X-ray reverberation, which exploits the time delays between variability in different energy bands as a function of Fourier frequency, probes the structure of the inner accretion disks and X-ray coronae of active galactic nuclei. We present…
View article: The QPO in RE J1034+396 Originates in the Hot Corona
The QPO in RE J1034+396 Originates in the Hot Corona Open
RE J1034+396 is one of the few active galactic nuclei (AGNs) with a significant quasiperiodic oscillation (QPO). The QPO has been observed in over 1 Ms of XMM-Newton observations spanning over a decade. We investigate the power spectral de…
View article: The QPO in REJ1034+396 originates in the hot corona
The QPO in REJ1034+396 originates in the hot corona Open
REJ1034+396 is one of the few active galactic nuclei with a significant quasi-periodic oscillation (QPO). The QPO has been observed in over 1 Ms of XMM-Newton observations spanning over a decade. We investigate the power spectral density f…
View article: Using the XMM-Newton small window mode to investigate systematic uncertainties in the particle background of X-ray charge-coupled device detectors
Using the XMM-Newton small window mode to investigate systematic uncertainties in the particle background of X-ray charge-coupled device detectors Open
The level and uncertainty of the particle-induced background in charge-coupled device (CCD) detectors play a crucial role in future X-ray instruments, such as the Wide Field Imager (WFI) onboard Athena. To mitigate the background systemati…
View article: An Exceptionally Powerful, Radiatively Driven Ultrafast Outflow in the Rapidly Accreting AGN RE J1034+396
An Exceptionally Powerful, Radiatively Driven Ultrafast Outflow in the Rapidly Accreting AGN RE J1034+396 Open
We report the analysis of ∼1 Ms of XMM-Newton observations of the rapidly accreting active galactic nucleus RE J1034+396. The 0.3–9 keV EPIC-pn spectra are well described by a model consisting of steep continuum emission from the corona ac…
View article: An Exceptionally Powerful, Radiatively Driven Ultrafast Outflow in the Rapidly Accreting AGN REJ1034+396
An Exceptionally Powerful, Radiatively Driven Ultrafast Outflow in the Rapidly Accreting AGN REJ1034+396 Open
We report the analysis of ~1Ms of XMM-Newton observations of the rapidly accreting active galactic nucleus REJ1034+396. The 0.3-9 keV EPIC-pn spectra are well described by a model consisting of steep continuum emission from the corona acco…
View article: The high energy X-ray probe (HEX-P): science overview
The high energy X-ray probe (HEX-P): science overview Open
To answer NASA’s call for a sensitive X-ray observatory in the 2030s, we present the High Energy X-ray Probe (HEX-P) mission concept. HEX-P is designed to provide the required capabilities to explore current scientific questions and make n…
View article: A View of the Long-term Spectral Behavior of Ultracompact X-Ray Binary 4U 0614+091
A View of the Long-term Spectral Behavior of Ultracompact X-Ray Binary 4U 0614+091 Open
In this study, we examine 51 archival NICER observations and six archival NuSTAR observations of the neutron star ultracompact X-ray binary (UCXB) 4U 0614+091, which span over 5 yr. The source displays persistent reflection features, so we…
View article: A View of the Long-Term Spectral Behavior of Ultra Compact X-Ray Binary 4U 0614+091
A View of the Long-Term Spectral Behavior of Ultra Compact X-Ray Binary 4U 0614+091 Open
In this study, we examine 51 archival NICER observations and 6 archival NuSTAR observations of the neutron star (NS) ultra-compact X-ray binary (UCXB) 4U 0614+091, which span over 5 years. The source displays persistent reflection features…
View article: Advancing Precision Particle Background Estimation for Future X-Ray Missions: Correlated Variability between the Alpha Magnetic Spectrometer and Chandra/XMM-Newton
Advancing Precision Particle Background Estimation for Future X-Ray Missions: Correlated Variability between the Alpha Magnetic Spectrometer and Chandra/XMM-Newton Open
Galactic cosmic-ray (GCR) particles have a significant impact on the particle-induced background of X-ray observatories, and their flux exhibits substantial temporal variability, potentially influencing background levels. In this study, we…
View article: The High-Energy X-ray Probe (HEX-P): the circum-nuclear environment of growing supermassive black holes
The High-Energy X-ray Probe (HEX-P): the circum-nuclear environment of growing supermassive black holes Open
Ever since the discovery of the first active galactic nuclei (AGN), substantial observational and theoretical effort has been invested into understanding how massive black holes have evolved across cosmic time. Circum-nuclear obscuration i…
View article: The outflowing ionised gas of I Zw 1 observed by HST COS
The outflowing ionised gas of I Zw 1 observed by HST COS Open
We present an analysis of the HST COS spectrum of IZw1 aiming to probe the absorbing medium associated with the active galactic nucleus (AGN). We fitted the emission spectrum and performed spectral analysis of the identified absorption fea…
View article: The outflowing ionised gas of I Zw 1 observed by HST COS
The outflowing ionised gas of I Zw 1 observed by HST COS Open
Aims. We present an analysis of the Hubble Space Telescope Cosmic Origins Spectrograph spectrum of I Zw 1 aiming to probe the absorbing medium associated with the active galactic nucleus (AGN). Methods. We fitted the emission spectrum and …
View article: The high energy X-ray probe (HEX-P): probing the physics of the X-ray corona in active galactic nuclei
The high energy X-ray probe (HEX-P): probing the physics of the X-ray corona in active galactic nuclei Open
The hard X-ray emission in active galactic nuclei (AGN) and black hole X-ray binaries is thought to be produced by a hot cloud of electrons referred to as the corona. This emission, commonly described by a power law with a high-energy cuto…
View article: The Current U.S. Labor Market: A Blip, or A New Trend?
The Current U.S. Labor Market: A Blip, or A New Trend? Open
View article: The High Energy X-ray Probe (HEX-P): The Circum-nuclear Environment of Growing Supermassive Black Holes
The High Energy X-ray Probe (HEX-P): The Circum-nuclear Environment of Growing Supermassive Black Holes Open
Ever since the discovery of the first Active Galactic Nuclei (AGN), substantial observational and theoretical effort has been invested into understanding how massive black holes have evolved across cosmic time. Circum-nuclear obscuration i…
View article: The High Energy X-ray Probe (HEX-P): Probing the physics of the X-ray corona in active galactic nuclei
The High Energy X-ray Probe (HEX-P): Probing the physics of the X-ray corona in active galactic nuclei Open
The hard X-ray emission in active galactic nuclei (AGN) and black hole X-ray binaries is thought to be produced by a hot cloud of electrons referred to as the corona. This emission, commonly described by a power law with a high-energy cuto…
View article: Wavelet spectral timing: X-ray reverberation from a dynamic black hole corona hidden beneath ultrafast outflows
Wavelet spectral timing: X-ray reverberation from a dynamic black hole corona hidden beneath ultrafast outflows Open
Spectral timing analyses based upon wavelet transforms provide a new means to study the variability of the X-ray emission from accreting systems, including AGN, stellar mass black holes and neutron stars, and can be used to trace the time …
View article: X-Ray/UVOIR Frequency-resolved Time Lag Analysis of Mrk 335 Reveals Accretion Disk Reprocessing
X-Ray/UVOIR Frequency-resolved Time Lag Analysis of Mrk 335 Reveals Accretion Disk Reprocessing Open
UV and optical continuum reverberation mapping is a powerful tool for probing the accretion disk and inner broad-line region. However, recent reverberation mapping campaigns in the X-ray, UV, and optical have found lags consistently longer…
View article: Orthomosaic and digital surface model of the main Casey station buildings, 12th February 2021.
Orthomosaic and digital surface model of the main Casey station buildings, 12th February 2021. Open
View article: X-ray/UVOIR Frequency-resolved Time Lag Analysis of Mrk 335 Reveals Accretion Disk Reprocessing
X-ray/UVOIR Frequency-resolved Time Lag Analysis of Mrk 335 Reveals Accretion Disk Reprocessing Open
UV and optical continuum reverberation mapping is powerful for probing the accretion disk and inner broad-line region. However, recent reverberation mapping campaigns in the X-ray, UV, and optical have found lags consistently longer than t…
View article: UV–Optical Disk Reverberation Lags despite a Faint X-Ray Corona in the Active Galactic Nucleus Mrk 335
UV–Optical Disk Reverberation Lags despite a Faint X-Ray Corona in the Active Galactic Nucleus Mrk 335 Open
We present the first results from a 100-day Swift, NICER, and ground-based X-ray–UV–optical reverberation mapping campaign of the Narrow-line Seyfert 1 Mrk 335, when it was in an unprecedented low X-ray flux state. Despite dramatic suppres…
View article: UV/Optical disk reverberation lags despite a faint X-ray corona in the AGN Mrk 335
UV/Optical disk reverberation lags despite a faint X-ray corona in the AGN Mrk 335 Open
We present the first results from a 100-day Swift, NICER and ground-based X-ray/UV/optical reverberation mapping campaign of the Narrow-Line Seyfert 1 Mrk 335, when it was in an unprecedented low X-ray flux state. Despite dramatic suppress…