Search Publications
Resurrecting Hitomi for Decaying Dark Matter and Forecasting Leading Sensitivity for XRISM
Safdi, Benjamin R.; Dessert, Christopher; Rodd, Nicholas L. +1 more
The Hitomi x-ray satellite mission carried unique high-resolution spectrometers that were set to revolutionize the search for sterile neutrino dark matter (DM) by looking for narrow x-ray lines arising from DM decays. Unfortunately, the satellite was lost shortly after launch, and to date the only analysis using Hitomi for DM decay used data taken…
Hitomi HXT deconvolution imaging of the Crab Nebula dazzled by the Crab pulsar
Maeda, Yoshitomo; Ishida, Manabu; Awaki, Hisamitsu +3 more
We develop a new deconvolution method to recover the precise Crab Nebula image taken by the Hitomi HXT, suppressing the artifact due to the bright Crab pulsar. We extend the Richardson-Lucy method, introducing two components corresponding to the nebula and pulsar with regularization for smoothness and flux, respectively, and performing simultaneou…
Investigating the Impact of Atomic Data Uncertainties on the Measured Physical Parameters of the Perseus Galaxy Cluster
Raymond, John; Foster, Adam R.; Smith, Randall +4 more
Accurate atomic data and plasma models are essential for interpreting the upcoming high-quality spectra from missions like XRISM and Athena. Estimating physical quantities, like temperature, abundance, turbulence, and the resonance scattering factor, is highly dependent on the underlying atomic data. We use the AtomDB tool variableapec to estimate…
Dark matter search in the Perseus cluster with simultaneous analysis of Hitomi and Suzaku data
Kitamoto, Shunji; Sawada, Makoto; Tamura, Takayuki +1 more
The reported detection of a 3.5 keV emission line in the Perseus cluster, possibly originating from dark matter decay, is still under scrutiny. Despite extensive observations, the detection has not yet been confirmed, and its origin remains a topic of active debate. Most of the previous searches relied on spectroscopy with X-ray charge-coupled dev…
Long-Term Density Trend in the Mesosphere and Lower Thermosphere From Occultations of the Crab Nebula With X-Ray Astronomy Satellites
Katsuda, Satoru; Enoto, Teruaki; Sato, Kosuke +9 more
We present long-term density trends of the Earth's upper atmosphere at altitudes between 71 and 116 km, based on atmospheric occultations of the Crab Nebula observed with X-ray astronomy satellites, ASCA, RXTE, Suzaku, NuSTAR, and Hitomi. The combination of the five satellites provides a time period of 28 years from 1994 to 2022. To suppress seaso…
Spectral break of energetic pulsar wind nebulae detected with wideband X-ray observations
Terada, Yukikatsu; Uchida, Hiroyuki; Bamba, Aya +4 more
Pulsar wind nebulae (PWNe) are one of the most energetic galactic sources with bright emissions from radio waves to very high-energy gamma-rays. We perform wideband X-ray spectroscopy of four energetic PWNe, N 157 B, PSR J1813-1749, PSR J1400-6325, and G21.5-0.9, with the Suzaku, Chandra, NuSTAR, and Hitomi observatories. A significant spectral br…
New Measurement of the Vertical Atmospheric Density Profile From Occultations of the Crab Nebula With X Ray Astronomy Satellites Suzaku and Hitomi
Katsuda, Satoru; Sato, Kosuke; Tashiro, Makoto S. +6 more
We present new measurements of the vertical density profile of the Earth's atmosphere at altitudes between 70 and 200 km, based on Earth occultations of the Crab Nebula observed with the X ray Imaging Spectrometer onboard Suzaku and the hard X ray Imager onboard Hitomi. X ray spectral variation due to the atmospheric absorption is used to derive t…
Probing the circumnuclear environment of NGC 1275 with high-resolution X-ray spectroscopy
Fabian, Andrew C.; Fukazawa, Yasushi; Veilleux, Sylvain +6 more
NGC 1275 is the brightest cluster galaxy (BCG) in the Perseus cluster and hosts the active galactic nucleus (AGN) that is heating the central 100 kpc of the intracluster medium atmosphere via a regulated feedback loop. Here, we use a deep (490 ks) Cycle-19 Chandra High-Energy Transmission Grating (HETG) observation of NGC 1275 to study the anatomy…
X-Ray Spectroscopy in the Microcalorimeter Era. II. A New Diagnostic on Column Density from the Case A to B Transition in H- and He-like Iron
Ferland, G. J.; Su, Y.; Chakraborty, P. +2 more
The Soft X-ray Spectrometer on board Hitomi, with the unprecedented resolving power of R ∼ 1250, allowed the detection of members of the Fe XXV Kα complex emission spectra from the center of the Perseus Cluster. In this paper, we introduce a novel method of measuring the column density using the optically thin (Case A) to optically thick (Case B) …
The Nonstandard Properties of a "Standard" PWN: Unveiling the Mysteries of PWN G21.5-0.9 Using Its IR and X-Ray Emission
Gelfand, Joseph D.; Temim, Tea; Slane, Patrick O. +3 more
The evolution of a pulsar wind nebula (PWN) depends on properties of the progenitor star, supernova, and surrounding environment. As some of these quantities are difficult to measure, reproducing the observed dynamical properties and spectral energy distribution (SED) with an evolutionary model is often the best approach to estimating their values…