500 citations · 3.7k across the 87 of their papers we have counts for
7 papers · 1 filter
Development of frequency domain multiplexing for the X-ray Integral Field Unit (X-IFU) on the Athena
Hiroki Akamatsu, Luciano Gottardi, Jan van der Kuur +11
We are developing the frequency domain multiplexing (FDM) read-out of transition-edge sensor (TES) microcalorimeters for the X-ray Integral Field Unit (X-IFU) instrument on board o…
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +213
Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host…
Hitomi constraints on the 3.5 keV line in the Perseus galaxy cluster
Hitomi Collaboration, Felix A. Aharonian, Hiroki Akamatsu +215
High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E=3.5 keV emission line reported in several low-resolution studies of va…
A multiplexer for the ac/dc characterization of TES based bolometers and microcalorimeters
Luciano Gottardi, Hiroki Akamatsu, Marcel Bruijn +9
At SRON we are developing the Frequency Domain Multiplexing (FDM) for the read-out of the TES-based detector array for the future infrared and X-ray space mission. We describe the…
Development of the superconducting detectors and read-out for the X-IFU instrument on board of the X-ray observatory Athena
Luciano Gottardi, Hiroki Akamatsu, Marcel P. Bruijn +6
The Advanced Telescope for High-Energy Astrophysics (Athena) has been selected by ESA as its second large-class mission. The future European X-ray observatory will study the hot an…
Josephson effects in an alternating current biased transition edge sensor
Luciano Gottardi, Alex Kozorezov, Hiroki Akamatsu +10
We report the experimental evidence of the ac Josephson effect in a transition edge sensor (TES) operating in a frequency domain multiplexer and biased by ac voltage at MHz frequen…
Turbulent Cosmic-Ray Reacceleration and the Curved Radio Spectrum of the Radio Relic in the Sausage Cluster
Yutaka Fujita, Hiroki Akamatsu, Shigeo S. Kimura
It has often been thought that the northern radio relic in the galaxy cluster CIZA J2242.8+5301 (the "Sausage" Cluster) is associated with cosmic ray (CR) electrons that are accele…