activity
20162026
most citedSpectral and Time Series Analyses of the Seyfert 1 AGN: Zw 229.015

14 citations · 53 across the 18 of their papers we have counts for

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17 papers · 1 filter

astro-ph.HE2026

XRISM High-Resolution X-ray Spectroscopy of Cygnus X-1 -- Orbital and Short-Term Variability of Iron Absorption

Kaito Ninoyu, Shinya Yamada, Natalie Hell +19

We present the first high-resolution spectroscopy of the black hole high-mass X-ray binary Cygnus X-1 with XRISM, including orbital-phase-resolved analyses and tentative evidence o…

astro-ph.HE2026★ 6 cited

XRISM High-Resolution X-ray Spectroscopy of Cygnus X-1 -- highly ionized Iron absorption structures

Shinya Yamada, Natalie Hell, Elisa Costantini +18

We present the first high-resolution X-ray spectral analysis of Cygnus X-1 using XRISM. The observation was carried out from April 7 to 10, 2024, covering the orbital phase range 0…

astro-ph.HE2026

A clean broad iron line in GS 1354--64 as seen by XRISM

Honghui Liu, Lingda Kong, Oluwashina K. Adegoke +13

We present a spectroscopic analysis of XRISM and NuSTAR observations of the black hole X-ray binary GS~1354--64 during its 2026 outburst. A total number of 3.5 million photons are…

astro-ph.HE2025

A XRISM View of Relativistic Reflection in Cygnus X-1

Paul A. Draghis, Jon M. Miller, Erin Kara +3

We present the first high-resolution XRISM/Resolve view of the relativistically broadened Fe K line in Cygnus X-1. The data clearly separate the relativistic broad line from the un…

astro-ph.HE2025

XRISM/Resolve reveals the complex iron structure of NGC 7213: Evidence for radial stratification between inner disk and broad-line region

E. Kammoun, T. Kawamuro, K. Murakami +48

We present the first high-resolution X-ray spectrum of NGC 7213 obtained with XRISM/Resolve, supported by simultaneous XMM-Newton, NuSTAR, and SOAR optical data. The XRISM spectrum…

astro-ph.HE2025

The 2025 Failed Outburst of IGR J17091-3624: Spectral Evolution and the Role of Ionized Absorbers

Oluwashina K. Adegoke, Javier A. Garcia, Guglielmo Mastroserio +15

IGR J17091-3624 is the only black hole X-ray binary candidate, aside from the well-studied black hole system GRS 1915+105, observed to exhibit a wide range of structured variabilit…

astro-ph.HE2025

The very high X-ray polarisation of accreting black hole IGRJ17091-3624 in the hard state

Melissa Ewing, Maxime Parra, Guglielmo Mastroserio +26

We report the first detection of the X-ray polarisation of the transient black hole X-ray binary IGRJ17091-3624 taken with the Imaging X-ray polarimetry Explorer (IXPE) in March 20…

astro-ph.HE2024

Characterizing the Broadband Reflection Spectrum of MAXI J1803-298 During its 2021 Outburst with NuSTAR and NICER

Oluwashina Adegoke, Javier Garcia, Riley Connors +12

MAXI J1803-298 is a transient black hole candidate discovered in May of 2021 during an outburst that lasted several months. Multiple X-ray observations reveal recurring "dipping" i…

astro-ph.HE2024

Rapid Mid-Infrared Spectral-Timing with JWST. I. The prototypical black hole X-ray Binary GRS 1915+105 during a MIR-bright and X-ray-obscured state

P. Gandhi, E. S. Borowski, J. Byrom +44

We present mid-infrared (MIR) spectral-timing measurements of the prototypical Galactic microquasar GRS 1915+105. The source was observed with the Mid-Infrared Instrument (MIRI) on…

astro-ph.HE2023

Variability as a predictor for the hard-to-soft state transition in GX 339-4

Matteo Lucchini, Marina Ten Have, Jingyi Wang +17

During the outbursts of black hole X-ray binaries (BHXRBs), their accretion flows transition through several states. The source luminosity rises in the hard state, dominated by non…

astro-ph.HE2023★ 5 cited

A Search for X-ray/UV Correlation in the Reflection-Dominated Seyfert 1 Galaxy Mrk 1044

Samuzal Barua, Oluwashina K. Adegoke, Ranjeev Misra +3

Correlated variability between coronal X-rays and disc optical/UV photons provides a very useful diagnostic of the interplay between the different regions around an active galactic…

astro-ph.HE2022★ 3 cited

Correlated variability of the reflection fraction with the X-ray flux and spectral index for Mkn 478

Samuzal Barua, V. Jithesh, Ranjeev Misra +2

The X-ray spectrum of Mkn 478 is known to be dominated by a strong soft excess which can be described using relativistic blurred reflection. Using observations from {\it XMM-Newton…

astro-ph.HE2022

XMM-Newton and Swift Observations of the Seyfert 1 AGN NGC 5940

Oluwashina K. Adegoke

Probing the physics of the accretion flow around active galactic nuclei (AGN) is crucial to understanding their emission mechanisms as well as being able to constrain the geometric…

astro-ph.HE2021

Spectro-Timing Analysis of a highly variable narrow-line Seyfert 1 galaxy NGC 4748 with AstroSat and XMM-Newton

Main Pal, Neeraj Kumari, Pankaj Kushwaha +8

We present a detailed timing and spectral study of an extremely variable narrow-line Seyfert~1 galaxy NGC 4748 using observations in the year 2017 and 2014 performed with AstroSat…

astro-ph.HE2020★ 4 cited

Correlating nonlinear time series and spectral properties of IGR J17091-3624: Is it similar to GRS 1915+105?

Oluwashina Adegoke, Banibrata Mukhopadhyay, Ranjeev Misra

We explore the nonlinear properties of IGR J17091-3624 in the line of the underlying behaviour for GRS 1915+105, following correlation integral method. We find that while the latte…

astro-ph.HE2018★ 12 cited

UV to X-ray Comptonization delay in Mrk 493

Oluwashina Adegoke, Gulab C. Dewangan, Pramod Pawar +1

The broadband X-ray emission from type 1 active galactic nuclei, dominated by a powerlaw continuum, is thought to arise from repeated inverse Compton scattering of seed optical/UV…

astro-ph.HE2018★ 9 cited

Correlating nonlinear properties with spectral states of RXTE data: Possible observational evidences for four different accretion modes around compact objects

Oluwashina Adegoke, Prasun Dhang, Banibrata Mukhopadhyay +2

By analyzing the time series of RXTE/PCA data, the nonlinear variabilities of compact sources have been repeatedly established. Depending on the variation in temporal classes, comp…