Hitomi unveiled the gas turbulence in Perseus cluster is small

Paper on the observation of Perseus cluster with Soft X-ray Spectrometer (SXS) onboard Hitomi to which our group has contributed will be published in Nature.

Galaxy cluster, which consists of hundreds of thousands of galaxies, emits X-ray due to its extremely hot gas captured by its strong gravity potential. The center of Perseus cluster where supermassive black hole has a jet pushing away a hot gas has been know to be dynamic. However, Hitomi unveiled its different aspect of the cluster; the gas turbulence was found to be much smaller than expected.

This result has been published in Nature online since 2016 July 6 (universal time).

Please check JAXA for detail.


2012-08-22 Kobayashi-san and Murakami-san received poster awards at the 3rd ASTRO-H summer school

We had the 3rd ASTRO-H summer school in Kyoto from 20 Aug. to 22  Aug. in Kyoto. The main topics of this year were supernovae remnants and particle acceleration.  Kobayashi-san and Murakami-san, master-course students of this laboratory, received poster awards for their posters about ULX and SNR observation-plans with ASTRO-H.


2012-07-12 The 39th COSPAR meeting was held at Mysore, India.

Hirofumi Noda and Makoto Sasano in PhD course of Makishima-Nakazawa laboratory attended the 39 the COSPAR meeting held at Mysore, India. They presented their new results obtained by analyzing the Suzaku data of Active Galactic Nuclei (AGNs), Supergiant Fast X-ray Transients (SFXTs) and Long Period Pulsars.


2012-02-29 Sakurai-san received the incentive award


2011-11-25 PASJ special issue of Suzaku and MAXI


2011-11-16 Prof. Makishima made an invited talk in the OMEG11 conference

Prof. Makishima gave an invited talk in an international conference, OMEG11 (The 11th International Symposium on Origin of Matter and Evolution of Galaxies), in Riken on  November 16, 2011. The theme was  neutron stars. The newest results of the “Suzaku” satellite and “MAXI” were reviewed. He also talked about expected scientific achievement of the next satellite ASTRO-H. The proceeding is here.


2011-02-24 Dr. Yuasa received the incentive award

Dr. Takayuki Yuasa received the incentive award of school of science by his Ph.D thesis ”
Suzaku Studies of White Dwarf Stars and the Galactic X-ray Background Emission”.
In this paper, he analyzed wide-band spectra data of 17 cataclysmic variables, which are obtained with Suzaku, using his own model. Based on that, he revealed that the spectrum of the Galactic ridge X-ray emission can be explained as the superposition of the cataclysmic variables and active binaries. This result strongly supports the superposition of point sources as the origin of the Galactic ridge X-ray emission. The detail is shown in this summary of Ph.D thesis. (Japanese only. Sorry.)


2010-09-25 Intermediate Polar paper published in A&A

Yuasa et al. 2010 was published in Astronomy & Astrophysics, European astrophysical journal,  volume 520 page A25. In the paper, authors studied X-ray spectra of 17 intermediate polars, or magnetic cataclysmic variable, using the spectrometers onboard the Suzaku satellite. By constructing a spectral emission model, the authors measured the temperature of a plasma which is heated by a strong standing shock near the WD surface, and estimated the mass of a WD from the plasma temperature. High sensitivity in the hard X-ray band and moderate energy resolution in the soft X-ray band allowed to improve accuracy of the estimation compared to previous studies.
The paper is available as a PDF from astro-ph (for free) or A&A (paid service).

2010-06-22 Joined The 3rd International SpaceWire Conference

The conference was held at very beautiful "House of Scientists".

Mr. Takayuki Yuasa (third grade of Ph.D course) joined “The 3rd International SpaceWire Conference” held in St. Petersburg from 22th to 24th of June 2010. He presented a successful test result of in-orbit test of SpaceWire system of SDS-I/SWIM and recent updates on SpaceWire-based data acquisition system for scientific instruments which has been jointly developed and used by JAXA/ISAS, Osaka University, The University of Tokyo, and many other institutes. A new SpaceWire device, SpaceWire-to-GigabitEther, attracted researchers in the conference and he got many inquiries about the device’s performance and usage.

Related links;


2009-12-03 Suzaku Results on GX 339-4 published in Astrophysical Journal Letters

Wide-band spectrum of GX 339-4 obtained with Suzaku.

Wide-band spectrum of GX 339-4 obtained with Suzaku.

Our GX 339-4 Suzaku results (Yamada et al. 2009) is available at  http://stacks.iop.org/1538-4357/707/L109 . GX 339-4 is one of the famous black hole candidates. Prof. Makishima’s GX 339-4 paper in 1986 established the method of estimating the inner radius of accretion disk around black holes. This paper again supported the results and successfully claimed that to find the consistency between emission line profile and thermal emission from disk is critically important.