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Hirofumi Noda

Hirofumi Noda
RIKEN | RIKEN AICS · Nishina Center for Accelerator-Based Science (RNC)

Ph.D.

About

75
Publications
4,829
Reads
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901
Citations
Additional affiliations
October 2013 - March 2014
The University of Tokyo
Position
  • JSPS Postdoctoral Researcher

Publications

Publications (75)
Article
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 (ICM) 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 ana...
Preprint
NGC1275 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 (ICM) atmosphere via a regulated feedback loop. Here we use a deep 490ks Cycle-19 Chandra High-Energy Transmission Grating (HETG) observation of NGC1275 to study the anatomy...
Article
X-ray emission generated through solar-wind charge exchange (SWCX) is known to contaminate X-ray observation data, the amount of which is often significant or even dominant, particularly in the soft X-ray band, when the main target consists of comparatively weak diffuse sources, depending on the space weather during the observation. In particular,...
Article
A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray Manuscript spectra with a pulsed muon beam at t...
Preprint
X-ray emission generated through solar-wind charge exchange (SWCX) is known to contaminate X-ray observation data, the amount of which is often significant or even dominant, particularly in the soft X-ray band, when the main target is comparatively weak diffuse sources, depending on the space weather during the observation. In particular, SWCX even...
Article
We investigate spatial distributions of iron Kα (Fe-Kα) lines in the cental 100 pc of the Seyfert 2 galaxy NGC 1068 observed with Chandra. The spatial distributions of Fe-Kα lines, neutral and highly ionized, around the center of the galactic nucleus are not isotropic, as consistently confirmed in both image and spectral analyses. The hydrogen numb...
Article
Full-text available
We have succeeded in operating a transition-edge sensor (TES) spectrometer and evaluating its performance at the SPring-8 synchrotron x-ray light source. The TES spectrometer consists of a 240 pixel National Institute of Standards and Technology (NIST) TES system, and 220 pixels are operated simultaneously with an energy resolution of 4 eV at 6 keV...
Article
X-ray Imaging Spectroscopy Mission (XRISM) is the next Japanese X-ray astronomical satellite to be launched in 2021 Japanese fiscal year. We are developing one of the XRISM instruments “Xtend”, which is an X-ray CCD camera combined with an X-ray telescope, and achieves the wide field of view of 38′×38′ in 0.4–13 keV. In 2019, twelve flight-model (F...
Article
We present experimental studies on the charge transfer inefficiency (CTI) of charge-coupled device (CCD) developed for the soft X-ray imaging telescope, Xtend, aboard the XRISM satellite. The CCD is equipped with a charge injection (CI) capability, in which sacrificial charge is periodically injected to fill the charge traps. By evaluating the re-e...
Preprint
Full-text available
Understanding and reducing the in-orbit instrumental backgrounds are essential to achieving high sensitivity in hard X-ray astronomical observations. The observational data of the Hard X-ray Imager (HXI) on board the Hitomi satellite provides useful information on the background components, owing to its multi-layer configuration with different atom...
Preprint
We present experimental studies on the charge transfer inefficiency (CTI) of charge-coupled device (CCD) developed for the soft X-ray imaging telescope, Xtend, aboard the XRISM satellite. The CCD is equipped with a charge injection (CI) capability, in which sacrificial charge is periodically injected to fill the charge traps. By evaluating the re-e...
Preprint
We have been developing P-channel Charge-Coupled Devices (CCDs) for the upcoming X-ray Astronomy Satellite XRISM, planned to be launched in 2021. While the basic design of the CCD camera (Soft X-ray Imager: SXI) is almost the same as that of the lost Hitomi (ASTRO-H) observatory, we are planning to reduce the "light leakages" that is one of the lar...
Preprint
We report the serendipitous discovery of a transient X-ray source, Suzaku J1305$-$4930, $\sim$3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku J1305$-$4930 was detected four times in July and August in 2010. The X-ray spectra are better approximated with a mul...
Article
We have been developing P-channel Charge-Coupled Devices (CCDs) for the upcoming X-ray Astronomy Satellite XRISM, planned to be launched in 2021. While the basic design of the CCD camera (Soft X-ray Imager: SXI) is almost the same as that of the lost Hitomi (ASTRO-H) observatory, we are planning to reduce the “light leakages” that is one of the lar...
Article
We report the serendipitous discovery of a transient X-ray source, Suzaku J1305−4930, ∼3 kpc southwest of the nucleus of the Seyfert 2 galaxy NGC 4945. Among the seven Suzaku observations of NGC 4945 from 2005 to 2011, Suzaku J1305−4930 was detected four times in July and August in 2010. The X-ray spectra are better approximated with a multi-color...
Preprint
We report X-ray spectroscopic results for four giant solar flares occurred on 2005 September 7 (X17.0), 2005 September 8 (X5.4), 2005 September 9 (X6.2), and 2006 December 5 (X9.0), obtained from Earth albedo data with the X-ray imaging spectrometer (XIS) onboard Suzaku. The good energy resolution of the XIS (FWHM$\sim$100 eV) enables us to separat...
Preprint
X-ray polarimetry in astronomy has not been exploited well, despite its importance. The recent innovation of instruments is changing this situation. We focus on a complementary MOS (CMOS) pixel detector with small pixel size and employ it as an x-ray photoelectron tracking polarimeter. The CMOS detector we employ is developed by GPixel Inc., and ha...
Article
ASTRO-H was an X-ray astronomy satellite that the Japan Aerospace Exploration Agency (JAXA) developed to study the evolution of the universe and physical phenomena yet to be discovered. The primary scientific instrument of ASTRO-H was the Soft X-ray Spectrometer (SXS). Its detectors were to be cooled to 50 m K using a complex cryogenic system with...
Article
Full-text available
Hard X-ray astronomical observatories in orbit suffer from a significant amount of background due to radioactivation induced by cosmic-ray protons and/or geomagnetically trapped protons. Within the framework of a full Monte Carlo simulation, we present modeling of in-orbit instrumental background which is dominated by radioactivation. To reduce the...
Article
The soft x-ray spectrometer (SXS) was a cryogenic high-resolution x-ray spectrometer onboard the Hitomi (ASTRO-H) satellite that achieved energy resolution of 5 eV at 6 keV, by operating the detector array at 50 mK using an adiabatic demagnetization refrigerator (ADR). The cooling chain from room temperature to the ADR heat sink was composed of two...
Article
When using superfluid helium in low-gravity environments, porous plug phase separators are commonly used to vent boil-off gas while confining the bulk liquid to the tank. Invariably, there is a flow of superfluid film from the perimeter of the porous plug down the vent line. For the soft x-ray spectrometer onboard ASTRO-H (Hitomi), its approximatel...
Article
The soft x-ray spectrometer (SXS) onboard the Hitomi satellite achieved a high-energy resolution of ∼4.9 eV at 6 keV with an x-ray microcalorimeter array cooled to 50 mK. The cooling system utilizes liquid helium, confined in zero gravity by means of a porous plug (PP) phase separator. For the PP to function, the helium temperature must be kept low...
Article
Soft X-ray Spectrometer instrument (SXS) is one of the primary scientific instruments of ASTRO-H. SXS has a cold detector that is cooled to 50 mK by using a multi-stage Adiabatic Demagnetization Refrigerator (ADR). SXS Dewar containing ADR provides 1.3 K heat sink by using liquid helium in nominal operation. After liquid helium is dried up, 4 K hea...
Conference Paper
Full-text available
We present the overall design and performance of the Astro-H (Hitomi) Soft X-Ray Spectrometer (SXS). The instrument uses a 36-pixel array of x-ray microcalorimeters at the focus of a grazing-incidence x-ray mirror Soft X-Ray Telescope (SXT) for high-resolution spectroscopy of celestial x-ray sources. The instrument was designed to achieve an energy...
Conference Paper
Hitomi X-ray observatory launched in 17 February 2016 had a hard X-ray imaging spectroscopy system made of two hard X-ray imagers (HXIs) coupled with two hard X-ray telescopes (HXTs). With 12 m focal length, they provide fine (2' half-power diameter; HPD) imaging spectroscopy at 5 to 80 keV. The HXI main imagers are made of 4 layers of Si and a CdT...
Conference Paper
The Soft X-ray Spectrometer (SXS) is the first space-based instrument to implement redundancy in the operation of a sub-Kelvin refrigerator. The SXS cryogenic system consists of a superfluid helium tank and a combination of Stirling and Joule-Thompson (JT) cryocoolers that support the operation of a 3-stage adiabatic demagnetization refrigerator (A...
Conference Paper
The Soft X-ray Spectrometer (SXS) is a cryogenic high-resolution X-ray spectrometer onboard the ASTRO-H satellite, that achieves energy resolution better than 7 eV at 6 keV, by operating the detector array at 50 mK using an adiabatic demagnetization refrigerator. The cooling chain from room temperature to the ADR heat sink is composed of 2-stage St...
Conference Paper
The Soft X-ray Spectrometer (SXS) onboard ASTRO-H (Hitomi) achieved a high energy resolution of ~ 4.9 eV at 6 keV with an X-ray microcalorimeter array kept at 50 mK in the orbit. The cooling system utilizes liquid helium, and a porous plug phase separator is utilized to confine it. Therefore, it is required to keep the helium temperature always low...
Conference Paper
We summarize all the in-orbit operations of the Soft X-ray Spectrometer (SXS) onboard the ASTRO-H (Hit- omi) satellite. The satellite was launched on 2016/02/17 and the communication with the satellite ceased on 2016/03/26. The SXS was still in the commissioning phase, in which the setups were progressively changed. This article is intended to serv...
Article
From 2013 April to 2014 April, we performed an X-ray and optical simultaneous monitoring of the type 1.5 Seyfert galaxy NGC 3516. It employed Suzaku, and 5 Japanese ground-based telescopes, the Pirka, Kiso Schmidt, Nayuta, MITSuME, and the Kanata telescopes. The Suzaku observations were conducted seven times with various intervals ranging from days...
Article
The bright and highly variable Seyfert I active galactic nucleus IC 4329A was observed with Suzaku five times in 2007 August, with intervals of ∼5 days and a net exposure of 24–31 ks each. Another longer observation was carried out in 2012 August with a net exposure of 118 ks. In the six observations, a source was detected in 2–45 keV with an avera...
Article
We have performed systematic studies of narrow Fe–K line (6.4 keV) flux variability and Ni–K line intensity for Seyfert galaxies, using Suzaku and XMM-Newton archival data. Significant Fe–K line variability of several tens of percent was detected for a pair of observations separated by 1000–2000 days (Cen A, IC 4329 A, NGC 3516, and NGC 4151) and 1...
Article
The Hard X-ray Imager (HXI) is one of the instruments onboard the ASTRO-H mission [1-4] to be launched in early 2016. The HXI is the focal plane detector of the hard X-ray reflecting telescope that covers an energy range from 5 to 80. keV. It will execute observations of astronomical objects with a sensitivity for point sources as faint as 1/100,00...
Article
Full-text available
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy ra...
Article
Full-text available
Thanks to extensive observations with X-ray missions and facilities working in other wavelengths, as well as rapidly--advancing numerical simulations of accretion flows, our knowledge of astrophysical black holes has been remarkably enriched. Rapid progress has opened new areas of enquiry, including measurements of black hole spin, the properties a...
Article
The Soft Gamma-ray Detector (SGD) is one of the instrument payloads onboard ASTRO-H, and will cover a wide energy band (60-600 key) at a background level 10 times better than instruments currently in orbit. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield. The Compton camera in the SGD i...
Article
Full-text available
The Hard X-ray Imager and the Soft Gamma-ray Detector, onboard the 6th Japanese X-ray satellite ASTRO-H, aim at unprecedentedly-sensitive observations in the 5–80 keV and 40–600 keV bands, respectively. Because their main sensors are composed of a number of semi-conductor devices, which need to be operated in a temperature of −20 to −15 • C, heat g...
Conference Paper
Full-text available
We present the development status of the Soft X-ray Spectrometer (SXS) onboard the ASTRO-H mission. The SXS provides the capability of high energy-resolution X-ray spectroscopy of a FWHM energy resolution of < 7eV in the energy range of 0.3 - 10 keV. It utilizes an X-ray micorcalorimeter array operated at 50 mK. The SXS microcalorimeter subsystem i...
Article
The Soft Gamma-ray Detector (SGD) is one of observational instruments onboard the ASTRO-H, and will provide 10 times better sensitivity in 60{600 keV than the past and current observatories. The SGD utilizes similar technologies to the Hard X-ray Imager (HXI) onboard the ASTRO-H. The SGD achieves low background by constraining gamma-ray events with...
Article
Full-text available
The type I Seyfert galaxy NGC 3227 was observed by \textit{Suzaku} six times in 2008, with intervals of $\sim1$ week and net exposures of $\sim50$~ksec each. Among the six observations, the source varied by nearly an order of magnitude, being brightest in the 1st observation with a 2--10~keV luminosity of $1.2\times10^{42}$~erg~s$^{-1}$, while fain...
Article
ASTRO-H is the sixth X-ray observation satellite in Japan developed by Institute of Space and Astronautical Science (ISAS/JAXA). ASTRO-H will investigate the physics of the high-energy universe by performing high-resolution and broadband observations. In order to achieve the mission objectives, ASTRO-H will carry six scientific instruments (two tel...
Article
Full-text available
The neutron-star Low-Mass X-ray Binary Aquila X-1 was observed by Suzaku for seven times, from 2007 September 28 to October 30. The observations successfully traced an outburst decay in which the source luminosity decreased almost monotonically from $\sim 10^{37}$ erg s$^{-1}$ to $\sim 10^{34}$ erg s$^{-1}$, by $\sim 3$ orders of magnitude. To inve...
Article
Full-text available
The bright type I Seyfert galaxy NGC 3516 was observed by Suzaku twice, in 2005 October 12-15 and 2009 October 28-November 2, for a gross time coverage of 242 and 544 ks and a net exposure of 134 and 255 ks, respectively. The 2-10 keV luminosity was 2.8 × 1041 erg s–1 in 2005 and 1.6 × 1041 erg s–1 in 2009. The 1.4-1.7 keV and 1.7-10 keV count rate...
Article
Full-text available
Unified X-ray spectral and timing studies of Cygnus X-1 in the low/hard and hard intermediate state were conducted in a model-independent manner, using broadband Suzaku data acquired on 25 occasions from 2005 to 2009 with a total exposure of $\sim$ 450 ks. The unabsorbed 0.1–500 keV source luminosity changed over 0.8%–2.8% of the Eddington limit fo...
Article
Full-text available
We present observations of a transient He-like Fe K alpha absorption line in Suzaku observations of the black hole binary Cygnus X-1 on 2011 October 5 near superior conjunction during the high/soft state, which enable us to map the full evolution from the start and the end of the episodic accretion phenomena or dips for the first time. We model the...
Article
Full-text available
Rapid spectral changes in the hard X-ray on a time scale down to ~0.1 s are studied by applying "shot analysis" technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles covering 10--200 keV with the Suzaku HXD-PIN and HXD-GSO detector....
Article
We analyzed high-quality broadband (0.5--300 keV) Suzaku data of Cyg X-1, acquired on 25 occasions in its low/hard state from 2005 to 2009 with a total exposure of ~ 450 ks. Unified spectral and timing analyses of these data sets revealed convincing evidence for a stable accretion disk and inhomogeneous coronae, reinforcing the view described in Ma...
Article
Full-text available
To constrain the origin of the soft X-ray excess phenomenon seen in many active galactic nuclei, the intensity-correlated spectral analysis, developed by Noda et al. (2011, PASJ, 63, S925) for Markarian 509, was applied to wide-band (0.5–45 keV) Suzaku data of five representative objects with a relatively weak reflection signature. They are the typ...
Article
The X-ray emission from Seyferts has been extensively studied, particularly to understand photon-reprocessing processes by circum-nuclear materials. However, our understanding of their central engine, which creates their primary X-ray continua presumably via Comptonization, has been fabulously insufficient, due to difficulties in quantifying these...
Article
Full-text available
The neutron-star Low-Mass X-ray Binary Aquila X-1 was observed seven times in total with the Suzaku X-ray observatory from September 28 to October 30 in 2007, in the decaying phase of an outburst. In order to constrain the flux-dependent accretion geometry of this source over wider energy bands than employed in most of previous works, the present s...
Article
Full-text available
We present the results of a systematic study of pileup phenomena seen in the X-ray Imaging Spectrometer, an X-ray CCD instrument, onboard the Suzaku observatory. Using a data set of observed sources in a wide range of brightness and spectral hardness, we characterized the pileup fraction, spectral hardening, and grade migration as a function of the...
Article
Full-text available
The Type I Seyfert galaxy Markarian 509 was observed with Suzaku in 2010 November, for a gross time span of 2.2 days. The timing and spectral properties of the 0.5–45 keV X-rays, detected with the XIS and HXD, consistently revealed the presence of a soft spectral component that remained constant while the total X-ray intensity varied by $\pm$ 10%....