149 research outputs found
Detection of Iron Emission Line from the Galaxy Cluster Including the Radio Galaxy 3C220.1 at z=0.62
We have detected an emission line feature at 4 keV in the X-ray emission from
a sky region including the distant radio galaxy 3C220.1(z=0.62) obtained with
ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of
3C220.1. Within the present statistics, the observed spectra are consistent
with two different models: a non-thermal model consisting of a power-law
continuum plus a 6.4 keV iron emission line, and a Raymond-Smith thin-thermal
emission model of kT ~6 keV with a metal abundance of ~0.5 solar. However,
because of the large (~ 500 eV) equivalent width of the line, a significant
fraction of the X-ray emission is likely to arise from the hot intracluster gas
associated with the galaxy cluster that includes 3C220.1. The spectral
parameters of the thermal emission are consistent with the
luminosity-temperature relation of nearby clusters.Comment: 15 pages, 5 ps figures, accepted for publication in the Astrophysical
Journa
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Successful cryopreservation of human ovarian cortex tissues using supercooling
The development of new method to cryopreserve human ovarian cortex tissues without damage is needed for the improvement of quality of life (QOL) of female cancer patients. Here we show novel cryopreservation method of human ovarian cortex tissues by using supercooling (S.C.) procedure. Our method will be helpful in order to preserve fertility of female cancer patients
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A therapeutic method for the direct reprogramming of human liver cancer cells with only chemicals
Various methods for the direct reprogramming of human somatic cells have been developed. However, a therapeutic method to reprogram and eliminate human solid tumor cells has not been developed. Here we show a novel therapeutic method to reprogram and eliminate human solid tumor cells with chemicals. This therapeutic method may be applicable to various human solid tumor cells that express aldo-keto reductase family 1 member B10 (AKR1B10) and retinoid X receptors (RXRs)
Suzaku Observations of SGR 1900+14 and SGR 1806-20
Spectral and timing studies of Suzaku ToO observations of two SGRs, 1900+14
and 1806-20, are presented. The X-ray quiescent emission spectra were well
fitted by a two blackbody function or a blackbody plus a power law model. The
non-thermal hard component discovered by INTEGRAL was detected by the PIN
diodes and its spectrum was reproduced by the power law model reported by
INTEGRAL. The XIS detected periodicity P = 5.1998+/-0.0002 s for SGR 1900+14
and P = 7.6022+/-0.0007 s for SGR 1806-20. The pulsed fraction was related to
the burst activity for SGR 1900+14.Comment: 8 pages, 3 figures, Accepted for publication in PASJ (Suzaku 3rd
special issue
A Spectral Study of the Black Hole Candidate XTE J1752-223 in the High/Soft State with MAXI, Suzaku and Swift
We report on the X-ray spectral analysis of the black hole candidate XTE\
J1752--223 in the 2009--2010 outburst, utilizing data obtained with the
MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work
complementarily. As already reported by Nakahira et al. (2010) MAXI monitored
the source continuously throughout the entire outburst for about eight months.
All the MAXI/GSC energy spectra in the high/soft state lasting for 2 months are
well represented by a multi-color disk plus power-law model. The innermost disk
temperature changed from 0.7 keV to 0.4 keV and the disk flux
decreased by an order of magnitude. Nevertheless, the innermost radius is
constant at 41 km, where is the
source distance in units of 3.5 kpc and the inclination. The multi-color
disk parameters obtained with the MAXI/GSC are consistent with those with the
Swift/XRT and Suzaku. The Suzaku data also suggests a possibility that the disk
emission is slightly Comptonized, which could account for broad iron-K features
reported previously. Assuming that the obtained innermost radius represents the
innermost stable circular orbit for a non-rotating black hole, we estimate the
mass of the black hole to be 5.510.28 , where the correction for the stress-free inner boundary condition
and color hardening factor of 1.7 are taken into account. If the inclination is
less than 49 as suggested from the radio monitoring of transient jets
and the soft-to-hard transition in 2010 April occurred at 1--4% of Eddignton
luminosity, the fitting of the Suzaku spectra with a relativistic
accretion-disk model derives constraints on the mass and the distance to be
3.1--55 and 2.3--22 {\rm kpc}, respectively. This confirms that the
compact object in XTE J1752--223 is a black hole.Comment: 12 pages including 7 figures and 4 tables, accepted for publication
in PAS
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