In-flight calibration of the Hitomi Soft X-ray Spectrometer. (2) Point spread function

X-Ray Imaging and Spectroscopy Mission (XRISM) is an x-ray astronomical mission led by the Japan Aerospace Exploration Agency (JAXA) and National Aeronautics and Space Administration (NASA), with collaboration from the European Space Agency (ESA) and other international participants, that is planned for launch in 2022 (Japanese fiscal year), to quickly restore high-resolution x-ray spectroscopy of astrophysical objects using the microcalorimeter array after the loss of Hitomi satellite. In order to enhance the scientific outputs of the mission, the Science Operations Team (SOT) is structured independently from the Instrument Teams (ITs) and the Mission Operations Team. The responsibilities of the SOT are divided into four categories: (1) guest observer program and data distributions, (2) distribution of analysis software and the calibration database, (3) guest observer support activities, and (4) performance

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Section: Lessons Learned From Hitomimentioning

confidence: 99%

Detailed design of the science operations for the XRISM mission

Terada

Holland

Loewenstein

et al. 2021

J. Astron. Telesc. Instrum. Syst.

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“…As a result, there were no delays in the schedule of software preparation and no delay in the release of tools and the calibration database. The products were well calibrated using instrument-specific methods, [12][13][14][15][16][17][18][19][20][21] because all the algorithms were imported into the analysis software and the latest calibration information was quickly released in the database. 5 2d-Hitomi − : In order to achieve 2c-Hitomi + , there were many interactions among the software and calibration team, instrument teams, and operation teams, which were spread across multiple agencies.…”

Section: Lessons Learned From Hitomimentioning

confidence: 99%

Detail plans and preparations for the science operations of the XRISM mission

Terada

Holland

Loewenstein

et al. 2020

Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray

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XRISM is an X-ray astronomical mission led by the Japan Aerospace Exploration Agency (JAXA) and National Aeronautics and Space Administration (NASA), with collaboration from the European Space Agency (ESA) and other international participants, that is planned for launch in 2022 (Japanese fiscal year), to quickly restore high-resolution X-ray spectroscopy of astrophysical objects using the micro-calorimeter array after the loss of Hitomi satellite. In order to enhance the scientific outputs of the mission, the Science Operations Team (SOT) is structured independently from the instrument teams and the Mission Operations Team (MOT). The responsibilities of the SOT are divided into four categories: 1) guest observer program and data distributions, 2) distribution of analysis software and the calibration database, 3) guest observer support activities, and 4) performance verification and optimization activities. Before constructing the operations concept of the XRISM mission, lessons on the science operations learned from past Japanese X-ray missions (ASCA, Suzaku, and Hitomi) are reviewed, and 15 kinds of lessons are identified by categories, such as lessons on the importance of avoiding nonpublic ("animal") tools, coding quality of public tools in terms of both the engineering viewpoint and calibration accuracy, tight communications with instrument teams and operations teams, well-defined task division between scientists and engineers, etc. Among these lessons, a) the importance of early preparation of the operations from the ground stage, b) construction of an independent team for science operations separate from the instrument development, and c) operations with well-defined duties by appointed members are recognized as key lessons for XRISM. Based on this, i) the task division between the mission and science operations and ii) the subgroup structure within the XRISM team are defined in detail as the XRISM Operations Concept. Based on this operations concept, the detailed plan of the science operations is designed as follows. The science operations tasks are shared among Japan, the US, and Europe and are performed by three centers: the Science Operations Center (SOC) at JAXA, the Science Data Center (SDC) at NASA, and European Space Astronomy Centre (ESAC) at the ESA. The SOT is defined as a combination of the SOC and SDC. The SOC is designed to perform tasks close to the spacecraft operations, such as spacecraft planning of science targets, quick-look health checks, pre-pipeline data processing, etc., and the SDC covers tasks regarding data calibration processing (pipeline processing), maintenance of analysis tools, etc. The data-archive and user-support activities are planned to be covered both by the SOC and SDC. Finally, the details of the science operations tasks and the tools for science operations are defined and prepared before launch. This information is expected to be helpful for the construction of science operations of future X-ray missions.

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Atmospheric gas dynamics in the Perseus cluster observed with Hitomi

Aharonia¹,

Aharonian

Akamatsu

et al. 2018

Publications of the Astronomical Society of Japan

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Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100 kpc of the Perseus cluster using observations obtained with the Hitomi satellite. After correcting for the point spread function of the telescope and using optically thin emission lines, we find that the line-of-sight velocity dispersion of the hot gas is remarkably low and mostly uniform. The velocity dispersion reaches a maxima of approximately 200 km s−1 toward the central active galactic nucleus (AGN) and toward the AGN inflated northwestern “ghost” bubble. Elsewhere within the observed region, the velocity dispersion appears constant around 100 km s−1. We also detect a velocity gradient with a 100 km s−1 amplitude across the cluster core, consistent with large-scale sloshing of the core gas. If the observed gas motions are isotropic, the kinetic pressure support is less than 10% of the thermal pressure support in the cluster core. The well-resolved, optically thin emission lines have Gaussian shapes, indicating that the turbulent driving scale is likely below 100 kpc, which is consistent with the size of the AGN jet inflated bubbles. We also report the first measurement of the ion temperature in the intracluster medium, which we find to be consistent with the electron temperature. In addition, we present a new measurement of the redshift of the brightest cluster galaxy NGC 1275.

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In-flight calibration of the Hitomi Soft X-ray Spectrometer. (2) Point spread function

Cited by 7 publications

References 15 publications

Detailed design of the science operations for the XRISM mission

Detailed design of the science operations for the XRISM mission

Detail plans and preparations for the science operations of the XRISM mission

Atmospheric gas dynamics in the Perseus cluster observed with Hitomi

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