Curriculum Vitaes
Profile Information
- Affiliation
- Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
- Degree
- Ph.D.(Jun, 2017, University of California, San Diego)
- Researcher number
- 40867032
- ORCID ID
https://orcid.org/0000-0003-0041-6447- J-GLOBAL ID
- 201901016586407138
- researchmap Member ID
- B000373123
Research Interests
3Research History
2Education
2-
Sep, 2010 - Jun, 2017
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Aug, 2005 - May, 2010
Awards
2-
Nov, 2013
Papers
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Journal of Cosmology and Astroparticle Physics, 2024(12) 036-036, Dec 1, 2024 Peer-reviewedAbstract Large angular scale surveys in the absence of atmosphere are essential for measuring the primordial B-mode power spectrum of the Cosmic Microwave Background (CMB). Since this proposed measurement is about three to four orders of magnitude fainter than the temperature anisotropies of the CMB, in-flight calibration of the instruments and active suppression of systematic effects are crucial. We investigate the effect of changing the parameters of the scanning strategy on the in-flight calibration effectiveness, the suppression of the systematic effects themselves, and the ability to distinguish systematic effects by null-tests. Next-generation missions such as LiteBIRD, modulated by a Half-Wave Plate (HWP), will be able to observe polarisation using a single detector, eliminating the need to combine several detectors to measure polarisation, as done in many previous experiments and hence avoiding the consequent systematic effects. While the HWP is expected to suppress many systematic effects, some of them will remain. We use an analytical approach to comprehensively address the mitigation of these systematic effects and identify the characteristics of scanning strategies that are the most effective for implementing a variety of calibration strategies in the multi-dimensional space of common spacecraft scan parameters. We verify that LiteBIRD's standard configuration yields good performance on the metrics we studied. We also present Falcons.jl, a fast spacecraft scanning simulator that we developed to investigate this scanning parameter space.
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Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 82-82, Aug 23, 2024
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Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 207-207, Aug 23, 2024
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XII, 124-124, Aug 16, 2024
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XII, 120-120, Aug 16, 2024
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Applied Optics, Aug 8, 2024
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JOURNAL OF LOW TEMPERATURE PHYSICS, 216(1-2) 119-128, Jul, 2024
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Journal of Astronomical Telescopes, Instruments, and Systems, 10(01), Jan 27, 2024
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Review of Scientific Instruments, 94(12), Dec 1, 2023
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Journal of Astronomical Telescopes, Instruments, and Systems, 9(02), Apr 19, 2023
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Ground test results of the electromagnetic interference for the x-ray microcalorimeter onboard XRISMJournal of Astronomical Telescopes, Instruments, and Systems, 9(1) 18004, Jan 1, 2023
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XI, Aug 31, 2022
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Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave, Aug 27, 2022
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Space Telescopes and Instrumentation 2022: Optical, Infrared, and Millimeter Wave, Aug 27, 2022
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Astrophys.J., 931(2) 101-101, May 27, 2022 Peer-reviewed
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Journal of Cosmology and Astroparticle Physics, 2022(4), Apr, 2022
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The Astrophysical Journal, 926(1) 54, Feb 1, 2022<jats:title>Abstract</jats:title> <jats:p>CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, <jats:italic>r</jats:italic>, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2–3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for <jats:italic>r</jats:italic> > 0.003 at greater than 5<jats:italic>σ</jats:italic>, or in the absence of a detection, of reaching an upper limit of <jats:italic>r</jats:italic> < 0.001 at 95% CL.</jats:p>
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Ground test results of the electromagnetic interference for the x-ray microcalorimeter onboard XRISMSPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY, 12181, 2022
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SPACE TELESCOPES AND INSTRUMENTATION 2022: OPTICAL, INFRARED, AND MILLIMETER WAVE, 12180, 2022
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Research Notes of the American Astronomical Society, Apr, 2021The Simons Observatory is a Cosmic Microwave Background experiment to observe the microwave sky in six frequency bands from 30 to 290 GHz. The Observatory—at ∼5200 m altitude—comprises three Small Aperture Telescopes and one Large Aperture Telescope (LAT) at the Atacama Desert, Chile. This research note describes the design and current status of the LAT along with its future timeline....
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Applied Optics, 60(4) 823-837, Feb 1, 2021
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Applied Optics, 60(4) 864-864, Jan 26, 2021Controlling stray light at millimeter wavelengths requires special optical design and selection of absorptive materials that should be compatible with cryogenic operating environments. While a wide selection of absorptive materials exists, these typically exhibit high indices of refraction and reflect/scatter a significant fraction of light before absorption. For many lower index materials such as commercial microwave absorbers, their applications in cryogenic environments are challenging. In this paper, we present a new tool to control stray light: metamaterial microwave absorber tiles. These tiles comprise an outer metamaterial layer that approximates a lossy gradient index anti-reflection coating. They are fabricated via injection molding commercially available carbon-loaded polyurethane (25% by mass). The injection molding technology enables mass production at low cost. The design of these tiles is presented, along with thermal tests to 1 K. Room temperature optical measurements verify their control of reflectance to less than 1% up to angles of incidence, and control of wide angle scattering below 0.01%. The dielectric properties of the bulk carbon-loaded material used in the tiles is also measured at different temperatures, confirming that the material maintains similar dielectric properties down to 3 K.
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PROCEEDINGS OF THE 14TH ASIA-PACIFIC PHYSICS CONFERENCE, 2319, 2021
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Ground-based and Airborne Telescopes VIII, Dec 18, 2020
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Review of Scientific Instruments, 91(12) 124503-124503, Dec 1, 2020 Peer-reviewed
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The Astrophysical Journal, 904(1) 65-65, Nov 20, 2020 Peer-reviewed
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Journal of Low Temperature Physics, 200(5-6) 461-471, Sep, 2020 Peer-reviewed
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Journal of Low Temperature Physics, 199(3-4) 1137-1147, May, 2020 Peer-reviewed
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The Astrophysical Journal, 893(1) 85-85, Apr 17, 2020 Peer-reviewed
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Internal Delensing of Cosmic Microwave Background Polarization B-Modes with the POLARBEAR ExperimentPhysical Review Letters, 124(13), Apr 1, 2020 Peer-reviewed
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Review of Scientific Instruments, 90(11) 115115-115115, Nov 1, 2019 Peer-reviewedLead authorCorresponding author
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The Astrophysical Journal, 882(1) 62-62, Sep 4, 2019 Peer-reviewed
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Journal of Cosmology and Astroparticle Physics, 2019(02) 056-056, Feb 27, 2019 Peer-reviewedThe Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial configuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping ≈ 10% of the sky to a white noise level of 2 μK-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio,r, at a target level of σ(r)=0.003. The large aperture telescope will map ≈ 40% of the sky at arcminute angular resolution to an expected white noise level of 6 μK-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from thePlancksatellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
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The Astrophysical Journal, 870(2) 102-102, Jan 14, 2019 Peer-reviewed
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Astrophysical Journal, 886(1) 38-38, 2019
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Journal of Low Temperature Physics, 193(5-6) 758-770, Dec, 2018 Peer-reviewed
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Journal of Low Temperature Physics, 193(5-6) 851-859, Dec, 2018 Peer-reviewed
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, Aug 6, 2018
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, Jul 31, 2018
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, Jul 9, 2018
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, Jul 9, 2018
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy IX, Jul 9, 2018 Lead author
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Ground-based and Airborne Telescopes VII, Jul 6, 2018
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Ground-based and Airborne Telescopes VII, Jul 6, 2018
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The Astrophysical Journal, 848(2) 121-121, Oct 23, 2017 Peer-reviewed
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Astrophysical Journal, 794(2), Oct 10, 2017 Peer-reviewed
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ASTROPHYSICAL JOURNAL, 848(1), Oct, 2017 Peer-reviewed
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Journal of Cosmology and Astroparticle Physics, 2017(05) 008-008, May 3, 2017 Peer-reviewed
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Astronomy & Astrophysics, 600 A60-A60, Apr, 2017 Peer-reviewedAnalysis of cosmic microwave background (CMB) datasets typically requires some filtering of the raw time-ordered data. For instance, in the context of ground-based observations, filtering is frequently used to minimize the impact of low frequency noise, atmospheric contributions and/or scan synchronous signals on the resulting maps. In this work we have explicitly constructed a general filtering operator, which can unambiguously remove any set of unwanted modes in the data, and then amend the map-making procedure in order to incorporate and correct for it. We show that such an approach is mathematically equivalent to the solution of a problem in which the sky signal and unwanted modes are estimated simultaneously and the latter are marginalized over. We investigated the conditions under which this amended map-making procedure can render an unbiased estimate of the sky signal in realistic circumstances. We then discuss the potential implications of these observations on the choice of map-making and power spectrum estimation approaches in the context of <italic>B</italic>-mode polarization studies. Specifically, we have studied the effects of time-domain filtering on the noise correlation structure in the map domain, as well as impact it may haveon the performance of the popular pseudo-spectrum estimators. We conclude that although maps produced by the proposed estimators arguably provide the most faithful representation of the sky possible given the data, they may not straightforwardly lead to the best constraints on the power spectra of the underlying sky signal and special care may need to be taken to ensure this is the case. By contrast, simplified map-makers which do not explicitly correct for time-domain filtering, but leave it to subsequent steps in the data analysis, may perform equally well and be easier and faster to implement. We focused on polarization-sensitive measurements targeting the <italic>B</italic>-mode component of the CMB signal and apply the proposed methods to realistic simulations based on characteristics of an actual CMB polarization experiment, POLARBEAR. Our analysis and conclusions are however more generally applicable.
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Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VIII, 9914, Aug 8, 2016
Misc.
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宇宙科学技術連合講演会講演集(CD-ROM), 67th, 2023
Presentations
58-
CMB-Inflate/C2C/IPNS/QUP workshop, Jan 29, 2025
Research Projects
2-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2020 - Mar, 2023
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Search for primordial gravitational wave using polarization of cosmic microwave background radiationGrants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Oct, 2017 - Mar, 2020
