activity
20102026
most citedPolarized x-rays constrain the disk-jet geometry in the black hole x-ray binary Cygnus X-1

173 citations · 2.6k across the 120 of their papers we have counts for

collaborators

127 papers

astro-ph.SR2026★ 2 cited

X-ray and Hα superflare on an RS CVn-type star, UX Arietis: Constraint on the flare location from radial velocity change during the flare

Sota Urabe, Yohko Tsuboi, Kosuke Namekata +5

We report on a giant stellar flare from the RS CVn-type binary UX Arietis, detected with the Monitor of All-sky X-ray Image (MAXI) and followed by a 12-day optical spectroscopic ca…

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.IM2026

In-orbit Demonstration of X-ray Pulsar Navigation with NinjaSat

Naoyuki Ota, Takuya Takahashi, Toru Tamagawa +26

This study demonstrated the pulsar navigation capability of the CubeSat X-ray observatory NinjaSat, which is equipped with two Gas Multiplier Counters (GMCs). The GMCs are sensitiv…

astro-ph.HE2025

Super-Eddington Accretion Geometry: a Remarkable Stability of the Hidden Ultraluminous X-Ray Source Cygnus X-3

Romana Mikušincová, Alexandra Veledina, Fabio Muleri +112

We report on the average and orbital phase-resolved polarization of Cyg X-3 in the hard state during the 2023 Imaging X-ray Polarimetry Explorer (IXPE) observational campaign. We f…

astro-ph.SR2025

Origin of the stellar Fe Kα line clarified with FUV and X-ray observations of a superflare on the RS Canum Venaticorum-type Star UX Arietis

Shun Inoue, Wataru Buz Iwakiri, Tomoki Kimura +11

Fluorescence line diagnostics of the Fe Kα line at keV observed in both solar and stellar flares can constrain the latitude and size of the flare loop, even in the absen…

astro-ph.HE2025

Unveiling the Nature of Superorbital Modulation of SMC X-1 using NinjaSat

Chin-Ping Hu, Naoyuki Ota, Takuya Takahashi +13

We report a long-term, high-cadence timing and spectral observation of the X-ray pulsar SMC X-1 using NinjaSat, a 6U CubeSat in low-Earth orbit, covering nearly a full superorbital…