activity
20152026
most citedA deep X-ray view of the bare AGN Ark120. IV. XMM-Newton and NuSTAR spectra dominated by two temperature (warm, hot) Comptonization processes

99 citations · 732 across the 55 of their papers we have counts for

collaborators

58 papers

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.IM2026

The statistical properties of the cross spectrum

Edward J. R. Nathan, Adam Ingram, Daniela Huppenkothen +2

The cross spectrum encodes the correlated variability between two time signals. In recent years, the cross spectrum has been used to study astronomical sources, particularly in the…

astro-ph.HE2026

Magnetic-field Order in the Southwestern Rim of RCW 86 Constrained Using X-Ray Polarimetry

Stefano Silvestri, Dmitry Prokhorov, Jacco Vink +97

RCW 86 is a supernova remnant whose origin has recently been linked to an off-center explosion within a cavity created by its progenitor star. In the southwestern region, the forwa…

astro-ph.HE2025★ 5 cited

Chlorine and Potassium Enrichment in the Cassiopeia A Supernova Remnant

XRISM collaboration

The elements in the universe are synthesized primarily in stars and supernovae, where nuclear fusion favors the production of even-Z elements. In contrast, odd-Z elements are less…

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 constraints on unidentified X-ray emission lines, including the 3.5 keV line, in the stacked spectrum of ten galaxy clusters

XRISM Collaboration, Marc Audard, Hisamitsu Awaki +150

We stack 3.75 Megaseconds of early XRISM Resolve observations of ten galaxy clusters to search for unidentified spectral lines in the 2.5-15 keV band (rest frame), including t…

astro-ph.HE2025★ 10 cited

Stratified wind from a super-Eddington X-ray binary is slower than expected

XRISM collaboration, Marc Audard, Hisamitsu Awaki +132

Accretion discs in strong gravity ubiquitously produce winds, seen as blueshifted absorption lines in the X-ray band of both stellar mass X-ray binaries (black holes and neutron st…

astro-ph.HE2025★ 1 cited

Disentangling Multiple Gas Kinematic Drivers in the Perseus Galaxy Cluster

XRISM Collaboration, Marc Audard, Hisamitsu Awaki +143

Galaxy clusters, the Universe's largest halo structures, are filled with 10-100 million degree X-ray-emitting gas. Their evolution is shaped by energetic processes such as feedback…

astro-ph.HE2025

Polarization of reflected X-ray emission from the Sgr A molecular complex: multiple flares, multiple sources?

Ildar Khabibullin, Eugene Churazov, Riccardo Ferrazzoli +100

The extended X-ray emission observed in the direction of several molecular clouds in the central molecular zone of our Galaxy exhibits spectral and temporal properties consistent w…

astro-ph.HE2025

X-ray Polarization Detection of the Pulsar Wind Nebula in G21.5-0.9 with IXPE

Niccolò Di Lalla, Nicola Omodei, Niccolò Bucciantini +98

We present the X-ray polarization observation of G21.5-0.9, a young Galactic supernova remnant (SNR), conducted with the Imaging X-ray Polarimetry Explorer (IXPE) in October 2023,…

astro-ph.HE2025

XRISM Spectroscopy of the Stellar-Mass Black Hole 4U 1630-472 in Outburst

Jon M. Miller, Misaki Mizumoto, Megumi Shidatsu +23

We report on XRISM/Resolve spectroscopy of the recurrent transient and well-known black hole candidate 4U 1630472 during its 2024 outburst. The source was captured at the end of…

astro-ph.HE2025★ 49 cited

Structured ionized winds shooting out from a quasar at relativistic speeds

XRISM collaboration

Evidence indicates that supermassive black holes exist at the centers of most galaxies. Their mass correlates with the galactic bulge mass, suggesting a co-evolution with their hos…

astro-ph.HE2025★ 15 cited

High optical to X-ray polarization ratio reveals Compton scattering in BL Lacertae's jet

Ivan Agudo, Ioannis Liodakis, Jorge Otero-Santos +147

Blazars, supermassive black hole systems (SMBHs) with highly relativistic jets aligned with the line of sight, are the most powerful long-lived emitters of electromagnetic emission…

astro-ph.HE2025

XRISM forecast for the Coma cluster: stormy, with a steep power spectrum

XRISM Collaboration, Marc Audard, Hisamitsu Awaki +142

The XRISM Resolve microcalorimeter array measured the velocities of hot intracluster gas at two positions in the Coma galaxy cluster: 3'x3' squares at the center and at 6' (170 kpc…

astro-ph.HE2025★ 8 cited

X-ray Polarization of the High-Synchrotron-Peak BL Lacertae Object 1ES 1959+650 during Intermediate and High X-ray Flux States

Luigi Pacciani, Dawoon E. Kim, Riccardo Middei +97

We report the Imaging X-ray Polarimetry Explorer (IXPE) polarimetric and simultaneous multiwavelength observations of the high-energy-peaked BL Lacertae (HBL) object 1ES 1959+650,…

astro-ph.HE2025★ 43 cited

The bulk motion of gas in the core of the Centaurus galaxy cluster

XRISM collaboration

Galaxy clusters, the largest gravitationally bound structures in the Universe, contain vast amounts of dark matter, galaxies, and hot ionised gas known as the intracluster medium (…

astro-ph.HE2024

Overionized plasma in the supernova remnant Sagittarius A East anchored by XRISM observations

XRISM Collaboration

Sagittarius A East is a supernova remnant with a unique surrounding environment, as it is located in the immediate vicinity of the supermassive black hole at the Galactic center, S…

astro-ph.HE2024

The XRISM/Resolve view of the Fe K region of Cyg X-3

XRISM Collaboration

The X-ray binary system Cygnus X-3 (4U 2030+40, V1521 Cyg) is luminous but enigmatic owing to the high intervening absorption. High-resolution X-ray spectroscopy uniquely probes th…

astro-ph.HE2024★ 10 cited

IXPE Observation of the Low-Synchrotron Peaked Blazar S4 0954+65 During An Optical-X-ray Flare

Pouya M. Kouch, Ioannis Liodakis, Francesco Fenu +134

The X-ray polarization observations made possible with the Imaging X-ray Polarimetry Explorer (IXPE) offer new ways of probing high-energy emission processes in astrophysical jets…

astro-ph.HE2024

A Two-Week Monitoring Campaign on Mrk 421

W. Peter Maksym, Ioannis Liodakis, M. Lynne Saade +153

X-ray polarization is a unique new probe of the particle acceleration in astrophysical jets made possible through the Imaging X-ray Polarimetry Explorer. Here we report on the firs…

astro-ph.HE2024

Analysis of Crab X-ray Polarization using Deeper IXPE Observations

Josephine Wong, Tsunefumi Mizuno, Niccoló Bucciantini +98

We present Crab X-ray polarization measurements using IXPE data with a total exposure of 300ks, three times more than the initial 2022 discovery paper. Polarization is detected in…

astro-ph.HE2024

X-ray and multiwavelength polarization of Mrk 501 from 2022 to 2023

Chien-Ting J. Chen, Ioannis Liodakis, Riccardo Middei +143

We present multiwavelength polarization measurements of the luminous blazar Mrk~501 over a 14-month period. The 2--8 keV X-ray polarization was measured with the Imaging X-ray Pola…

astro-ph.HE2024

An IXPE-Led X-ray Spectro-Polarimetric Campaign on the Soft State of Cygnus X-1: X-ray Polarimetric Evidence for Strong Gravitational Lensing

James F. Steiner, Edward Nathan, Kun Hu +134

We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May-June. Companion multiwav…