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- Aharonian, Felix, et al.
(författare)
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Hitomi X-ray studies of giant radio pulses from the Crab pulsar
- 2018
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Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:2
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Tidskriftsartikel (refereegranskat)abstract
- To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2-300 keV band and the Kashima NICT radio telescope in the 1.4-1.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 sigma fluctuations of the X-ray fluxes at the pulse peaks, and the 3 sigma upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2-300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.5-10 keV and 70-300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) x 10(-11) erg cm(-2), respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magneto-sphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a > 0.02% brightening of the pulse-peak flux under such conditions.
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| 2. |
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| 3. |
- Karlsson, Charlie, 1945-, et al.
(författare)
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Infrastructure Measurement and Management – An Introduction
- 2007
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Ingår i: Management and Measurement of Infrastructure. Performance, Efficiency and Innovation. - Cheltenham : Edward Elgar Publishing. - 9781845426439 ; , s. 1-21
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 5. |
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| 6. |
- Naruse, Makoto, et al.
(författare)
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Lower bound of energy dissipation in optical excitation transfer via optical near-field interactions
- 2010
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Ingår i: Optics Express. - 1094-4087. ; 18:23, s. A544-A553
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Tidskriftsartikel (refereegranskat)abstract
- We theoretically analyzed the lower bound of energy dissipation required for optical excitation transfer from smaller quantum dots to larger ones via optical near-field interactions. The coherent interaction between two quantum dots via optical near-fields results in unidirectional excitation transfer by an energy dissipation process occurring in the larger dot. We investigated the lower bound of this energy dissipation, or the intersublevel energy difference at the larger dot, when the excitation appearing in the larger dot originated from the excitation transfer via optical near-field interactions. We demonstrate that the energy dissipation could be as low as 25 mu eV. Compared with the bit flip energy of an electrically wired device, this is about 10(4) times more energy efficient. The achievable integration density of nanophotonic devices is also analyzed based on the energy dissipation and the error ratio while assuming a Yukawa-type potential for the optical near-field interactions.
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| 9. |
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Social Capital and Development Trends in Rural Areas : The Role of Social Entrepreneurship and Social Capital in Rural Renewal
- 2015
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Samlingsverk (redaktörskap) (refereegranskat)abstract
- This volume contains the examined and selected papers of the 11th InternationalWorkshop on “Social Capital and Development Trends in Japan’s and Sweden’s Countryside.”The workshop was held in August 21–23, 2014 in Östersund, Jämtland, Sweden and its aim wasto discuss common topics of non-metropolitan and rural regions and urban-rural interaction inSweden and Japan, with the concepts of social capital and social entrepreneurship as commondenominators. The volume consists of 17 contributions by authors from Sweden and Japan, suc-cessfully accepted through peer review. The book presents interesting and diverse viewpointson the interface between the concept of social capital and the development of rural regions.
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