ORCID Profile
0000-0002-6174-8165
Current Organisation
東京大学
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Publisher: American Astronomical Society
Date: 07-2022
Abstract: In this Letter, we report the discovery of an ultraluminous fast-evolving transient in rest-frame UV wavelengths, MUSSES2020J, soon after its occurrence by using the Hyper Suprime-Cam (HSC) mounted on the 8.2 m Subaru telescope. The rise time of about 5 days with an extremely high UV peak luminosity shares similarities to a handful of fast blue optical transients whose peak luminosities are comparable with the most luminous supernovae while their timescales are significantly shorter (hereafter “fast blue ultraluminous transient,” FBUT). In addition, MUSSES2020J is located near the center of a normal low-mass galaxy at a redshift of 1.063, suggesting a possible connection between the energy source of MUSSES2020J and the central part of the host galaxy. Possible physical mechanisms powering this extreme transient such as a wind-driven tidal disruption event and an interaction between supernova and circumstellar material are qualitatively discussed based on the first multiband early-phase light curve of FBUTs, although whether the scenarios can quantitatively explain the early photometric behavior of MUSSES2020J requires systematical theoretical investigations. Thanks to the ultrahigh luminosity in UV and blue optical wavelengths of these extreme transients, a promising number of FBUTs from the local to the high- z universe can be discovered through deep wide-field optical surveys in the near future.
Publisher: American Astronomical Society
Date: 25-09-2017
Publisher: Oxford University Press (OUP)
Date: 25-02-2010
DOI: 10.1093/PASJ/62.1.19
Publisher: American Astronomical Society
Date: 25-08-2016
Publisher: American Astronomical Society
Date: 03-07-2018
Publisher: American Astronomical Society
Date: 21-05-2010
Publisher: Oxford University Press (OUP)
Date: 09-02-2011
DOI: 10.1093/PASJ/PSX046
Publisher: American Astronomical Society
Date: 02-2003
DOI: 10.1086/345962
Publisher: Oxford University Press (OUP)
Date: 10-10-2018
DOI: 10.1093/PASJ/PSY101
Publisher: American Astronomical Society
Date: 23-02-2016
Publisher: American Astronomical Society
Date: 24-10-2019
Publisher: American Astronomical Society
Date: 10-2019
Abstract: We report the discovery of 28 quasars and 7 luminous galaxies at 5.7 ≤ z ≤ 7.0. This is the tenth in a series of papers from the Subaru High- z Exploration of Low-Luminosity Quasars (SHELLQs) project, which exploits the deep multiband imaging data produced by the Hyper Suprime-Cam (HSC) Subaru Strategic Program survey. The total number of spectroscopically identified objects in SHELLQs has now grown to 93 high- z quasars, 31 high- z luminous galaxies, 16 [O iii ] emitters at z ∼ 0.8, and 65 Galactic cool dwarfs (low-mass stars and brown dwarfs). These objects were found over 900 deg 2 , surveyed by HSC between 2014 March and 2018 January. The full quasar s le includes 18 objects with very strong and narrow Ly α emission, whose stacked spectrum is clearly different from that of other quasars or galaxies. While the stacked spectrum shows N v λ 1240 emission and resembles that of lower- z narrow-line quasars, the small Ly α width may suggest a significant contribution from the host galaxies. Thus, these objects may be composites of quasars and star-forming galaxies.
Publisher: American Astronomical Society
Date: 20-12-2018
Publisher: American Astronomical Society
Date: 06-02-2019
Publisher: Springer Science and Business Media LLC
Date: 02-2016
DOI: 10.1038/NATURE17140
Abstract: In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.
Location: Japan
No related grants have been discovered for Hisanori Furusawa.