Search

We observed a stellar occultation by (3200) Phaethon, which occurred in western Japan on 2021 October 3 (UTC). This observation was requested by the DESTINY+ mission team, which plans to conduct a flyby of asteroid Phaethon in 2028. Overall, this research effort contributes towards a large-scale observation campaign with a total of 72 observers observing from western Japan to southern Korea. 36 stations were established, and stellar occultation by the asteroid Phaethon was detected in 18 of them. This is the first time that this many multiple chord observations have been made for such a small asteroid (it has a diameter of 5–6 km). Observational reductions show that the apparent cross-section of Phaethon at the time of the occultation could be approximated using an ellipse with a major diameter of 6.12 ± 0.07 km and a minor diameter of 4.14 ± 0.07 km, and a position angle of 117.°4 ± 1.°5. As can be seen from the small error bars of the fitted ellipse, we have succeeded in estimating the shape and size of the asteroid with an extremely high degree of accuracy. Our observation results, together with other observations, will be used to create a 3D model of Phaethon and to improve its orbit. The instruments that we used for this observation are commonly used by many amateur astronomers in Japan for occultation observations and are not difficult to obtain. This paper describes the method and results of our observations using a CMOS camera and a GPS module, so that many people can participate in occultation observations in the future.

The zodiacal light (ZL) is sunlight scattered by interplanetary dust (IPD) in the optical wavelengths. The spatial distribution of IPD in the Solar system may hold an important key to understanding the evolution of the Solar system and material transportation within it. The IPD number density can be expressed as [[EQUATION]] , and the result of [[EQUATION]] was obtained by the previous observations from the interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of [[EQUATION]] based on the ZL observation from the interplanetary space outside the Earth's orbit have been conducted since then. Here we introduce the initial result of the ZL radial profile at optical wavelengths observed at 0.76-1.06 au by ONC-T with Hayabusa2# mission in 2021-2022. The obtained ZL brightness is well reproduced by the model brightness, but there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The obtained radial power-law index is [[EQUATION]] , which is consistent with the previous results based on the ZL observations. The dominant uncertainty source arises from the uncertainty in the Diffuse Galactic Light estimation.

We report near-infrared polarization of the zodiacal light (ZL) measured from space by the Diffuse Infrared Background Experiment (DIRBE) on board the Cosmic Background Explorer in photometric bands centered at 1.25, 2.2, and 3.5 $\mu$m. To constrain the physical properties of interplanetary dust (IPD), we use DIRBE Weekly Sky Maps to investigate the solar elongation ($\epsilon$), ecliptic latitude ($\beta$), and wavelength ($\lambda$) dependence of ZL polarization. We find that the polarization of the ZL varies as a function of $\epsilon$ and $\beta$, consistent with observed polarization at $\lambda$ = 550 nm. While the polarization dependence with wavelength at $(\epsilon$, $\beta)=(90^{\circ}$, $0^{\circ})$ is modest (increasing from 17.7 $\pm$ 0.2% at 1.25 $\mu$m to 21.0 $\pm$ 0.3% at 3.5 $\mu$m), the variation is more pronounced at the North Ecliptic Pole (23.1 $\pm$ 1.6, 35.1 $\pm$ 2.0 and 39.3 $\pm$ 2.1% at 1.25, 2.2 and 3.5 $\mu$m, respectively). The variation of ZL polarization with wavelength is not explained by either Rayleigh scattering or by absorptive particles larger than 10 $\mu$m., Comment: 11 pages, 12 figures, accepted by ApJ

Purpose False-negative findings in radiological reports can lead to serious adverse patient outcomes. We determined the frequency and tendency of false-negative findings in radiological reports by searching for words related to “visible in retrospect”. Methods In the period of 34 months, we extracted radiological reports containing words related to “visible in retrospect”. Of these reports, we extracted false-negative findings that were not described in past reports and were first detected retrospectively. Misinterpretations were excluded. The occurrences of the terms that we identified were analyzed by all examinations, modality, month, and anatomical and lesion classifications were analyzed. Results Of the 135,251 examinations, 941 reports (0.71%) with 962 findings were detected, with an average of 1.4 findings per business day. By modality, 713 of 81,899 (0.87%) CT examinations, 208 of 36,174 (0.57%) MR, 34 of 9,585 (0.35%) FDG-PET-CT, 2 of 2,258 (0.09%) digital radiography, and 5 of 5,335 (0.09%) other nuclear medicine examinations were found. By anatomical classification, there were 383 (40%) in chest, 353 (37%) in abdomen, 162 (17%) in head, 42 (4.4%) in face and neck, 9 (0.93%) in extremity, and 13 (1.4%) in others. By lesion classification, we identified 665 (69%) for localized lesion, 170 (18%) for vascular lesion, 83 (8.6%) for inflammatory lesion, 14 (1.5%) for traumatic lesion, 12 (1.2%) for organ dysfunction, 11 (1.1%) for degenerative lesion, and 7 (0.7%) for the others. Notable high-frequency specific site diseases by modality were 210 (22%) of localized lesions in lung on CT. Conclusion Our results demonstrated that missed lung localized lesions on CT, which account for about a fifth of false-negative findings, were the most common false-negative finding.

We report the first measurement of the zodiacal light (ZL) polarization spectrum in the near-infrared between 0.8 and 1.8 $\mu$m. Using the low-resolution spectrometer (LRS) on board the Cosmic Infrared Background Experiment (CIBER), calibrated for absolute spectrophotometry and spectropolarimetry, we acquire long-slit polarization spectral images of the total diffuse sky brightness towards five fields. To extract the ZL spectrum, we subtract contribution of other diffuse radiation, such as the diffuse galactic light (DGL), the integrated star light (ISL), and the extragalactic background light (EBL). The measured ZL polarization spectrum shows little wavelength dependence in the near-infrared and the degree of polarization clearly varies as a function of the ecliptic coordinates and solar elongation. Among the observed fields, the North Ecliptic Pole shows the maximum degree of polarization of $\sim$ 20$\%$, which is consistent with an earlier observation from the Diffuse Infrared Background Experiment (DIRBE) aboard on the Cosmic Background Explorer (COBE). The measured degree of polarization and its solar elongation dependence are reproduced by the empirical scattering model in the visible band and also by the Mie scattering model for large absorptive particles, while the Rayleigh scattering model is ruled out. All of our results suggest that the interplanetary dust is dominated by large particles., Comment: 15 pages, 15 figures, accepted by ApJ

In response to the recommendation by the International Commission on Radiological Protection to lower the equivalent eye dose limit, the Japanese Government in April 2021 lowered the equivalent dose limit for the eye lens for occupational exposure. A considerable number of interventional radiology operators are exposed to levels above the new limit. For this reason, a need exists to more accurately evaluate eye lens dose in interventional radiology operators by using a novel direct eye dosimeter, the DOSIRIS™(IRSN, France), which is capable of measuring a 3-mm dose equivalent under protective glasses. The DOSIRIS is a thermoluminescent dosimeter that exhibits good energy dependence and better directional properties than other dosimeters. Dosimetry using DOSIRIS might be accurate and compatible with the latest regulations.

The COBAND is a project of an experimental search for the cosmic background neutrino decay [1] – [9] . The existence of the cosmic background neutrino is predicted as a relic of the big bang in the theoretical cosmology. Since the neutrino is found to have mass generations and mixing between them, a heavier neutrino is possible to decay to a lighter neutrino with a far-infrared photon, even though its lifetime is expected to be much longer than the age of the universe [10] . However, neither the cosmic background neutrino nor the neutrino decay is yet established experimentally. Only a lower limit in the order of 10 12 years is given on the heaviest neutrino lifetime. We, thus, search for photons which come from the cosmic background neutrino decays. The photons from the cosmic background neutrino decays are expected to shape a spectrum of a unique signature with a sharp edge at a wavelength of around 50μm depending on the heaviest neutrino mass. To identify the signature against the overwhelming zodiacal emission foreground as well as the cosmic infrared background, the photodetectors are required to have an ability to measure the FIR spectrum around 50pm with sufficient precision. Thus, we aim at developing a photodetector with capability of FIR photon-by-photon spectrometry. We employ superconducting tunnel junction (STJ) sensors in combination with cryogenic amplifiers for signal readout to maximize the potential of STJ.

著者人数: 66名 (所属. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS): 岩田, 隆浩; 安部, 正真; 大竹, 真紀子; 仲内, 悠佑; 松岡, 萌; L. Riu; 中藤, 亜衣子; 横田, 康弘; 坂谷, 尚哉; 山本, 幸生; 岡田, 達明; 澤田, 弘崇, 早川, 雅彦; 白井, 慶; 嶌生, 有理; 尾川, 順子; 照井, 冬人; 竹井, 洋; 佐伯, 孝尚; 中澤, 暁; 田中, 智; 吉川, 真; 渡邊, 誠一郎; 津田, 雄一), Accepted: 2019-03-07, 資料番号: SA1180385000

Asteroid Ryugu was observed up close for almost a year and a half by the instruments on-board the Japanese Aerospace eXploration Agency (JAXA) Hayabusa2 spacecraft. It has been shown that in the near-infrared wavelength ranges, the asteroid exhibits relatively homogeneous spectral characteristics: including a very low reflectance factor, a slight red slope towards longer wavelengths, and a narrow and weak absorption feature centered at 2.72 μm. Numerous craters have been identified at the surface of Ryugu. These features provide good candidates for studying more recently exposed near-surface material to further assess potential spectral/compositional heterogeneities of Ryugu. We present here the results of a spectral survey of all previously identified and referenced craters (Hirata et al. 2020) based on reflectance data acquired by the NIRS3 spectrometer. Globally, we find that the spectral properties inside and outside of craters are very similar, indicating that subsurface material is either compositionally similar to material at the surface that has a longer exposure age or that material at Ryugu’s optical surface is spectrally altered over relatively short timescales by external factors such as space weathering. The 2.72 μm band depth, present on the overall surface, exhibits a slight anti-correlation with the reflectance factor selected at 2 μm, which could indicate different surface properties (e.g., grain size and/or porosity) or different alteration processes (e.g., space weathering, shock metamorphism and/or solar heating). We identified four different spectral classes based on their reflectance factor at 2 μm and 2.72 μm absorption strength. The most commonly spectral behavior associated with crater floors, is defined by a slightly lower reflectance at 2 μm and deeper band depth. These spectral characteristics are similar to those of subsurface material excavated by the Hayabusa2 small carry-on impactor (SCI) experiment, suggesting these spectral characteristics may represent materials with a younger surface exposure age. Conversely, these materials may have experienced significant solar heating and desiccation to form finer grains that subsequently migrated towards and preferentially accumulated in areas of low geopotential, such as craters floors. Detailed analyses of the returned samples of Ryugu that are now being investigated at the curation facility in ISAS will allow for further testing of these formation and alteration hypotheses.

Analyses of meteorites and theoretical models indicate that some carbonaceous near-Earth asteroids may have been thermally altered due to radiative heating during close approaches to the Sun1–3. However, the lack of direct measurements on the subsurface doesn’t allow us to distinguish thermal alteration due to radiative heating from parent-body processes. In April 2019, the Hayabusa2 mission successfully completed an artificial impact experiment on the carbonaceous near-Earth asteroid (162173) Ryugu4,5, which provided an opportunity to investigate exposed subsurface material and test potential effects of radiative heating. Here we report observations of Ryugu’s subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. The strength and shape of the OH feature suggests that the subsurface material experienced heating above 300 °C, similar to the surface. In contrast, thermophysical modelling indicates that radiative heating cannot increase the temperature above 200 °C at the estimated excavation depth of 1 m, even at the smallest heliocentric distance possible for Ryugu. This supports the hypothesis that primary thermal alteration occurred on Ryugu’s parent body. Hayabusa2 created an artificial crater on Ryugu to analyse the subsurficial material of the asteroid. Results show that the subsurface is more hydrated than the surface. It experienced alteration processes that can be traced back to Ryugu’s parent body.

HiZ-GUNDAM is a future satellite mission which will lead the time-domain astronomy and the multi-messenger astronomy through observations of high-energy transient phenomena. A mission concept of HiZ-GUNDAM was approved by ISAS/JAXA, and it is one of the future satellite candidates of JAXA’s medium-class mission. We are in pre-phase A (before pre-project) and elaborating the mission concept, mission/system requirements for the launch in the late 2020s. The main themes of HiZ-GUNDAM mission are (1) exploration of the early universe with high-redshift gamma-ray bursts, and (2) contribution to the multi-messenger astronomy. HiZ-GUNDAM has two kinds of mission payload. The wide field X-ray monitors consist of Lobster Eye optics array and focal imaging sensor, and monitor ~1 steradian field of view in 0.5 – 4 keV energy range. The near infrared telescope has an aperture size 30 cm in diameter, and simultaneously observes four wavelength bands between 0.5 – 2.5 μm. In this paper, we introduce the mission overview of HiZ-GUNDAM.

Extragalactic background light (EBL) consists of entire radiation emitted throughout the cosmic history and is one crucial observable quantity to study astrophysics in the early universe, such as first stellar objects or primordial black holes. In the visible and near-infrared, zodiacal light (ZL), sunlight scattered by interplanetary dust, is the brightest foreground for observer in the near-earth orbit and its uncertainty limits accuracy of the EBL measurement. To overcome this problem, observations from heliocentric distance beyond 5 au, where the ZL is negligible, is promising. To achieve the EBL observation in deep space, we have been developing EXo- Zodiacal Infrared Telescope (EXZIT) onboard a solar sail spacecraft to Jovian Trojans planned in Japan around 2030. According to our mission study, a three-mirror reflective telescope optics design with a 90mm × 50mm effective aperture and 16 deg × 8 deg field of view (FoV) followed by a focal plane array HAWAII-2RG with a linear variable filter makes available to detect the EBL at high significance in 0.4–1.6 μm with specific wavelength resolution of ∼ 20 . In the present study, we develop test optics to demonstrate optical performance in room temperature for the future observation. By adopting only mirrors of aspherical surface, we design the optics whose aberration is minimized to show point spread function (PSF) of approximately 3 pix × 3 pix on the focal plane. The mirrors are fabricated by machining aluminum alloy A6061 with a honeycomb processing on the back surface to reduce the mirror mass. After integrating and aligning the mirrors with support jigs, we measure the PSF on the focal plane by a visible camera by inserting collimated beam of different angle of incidence, covering the whole FoV. We evaluate the PSF size by analyzing encircled energy in comparison with that expected from the ray-trace simulation of the optics. Throughout the FoV of the optics, the measured PSF size is comparable to the simulation. The present study demonstrates the precision machining of the aspherical mirrors and the optical performance of the designed optics. As a next step, we plan to develop thermal structure of EXZIT to demonstrate the optical performance in low temperature.

The total integrated emission from galaxies, known as the Extragalactic Background Light (EBL), is an important observable for understanding the history of star formation over the history of the universe. Spatial fluctuations in the infrared EBL as measured by the Cosmic Infrared Background ExpeRiment (CIBER), Spitzer and AKARI exceed the predicted signal from galaxy clustering alone. The CIBER-2 project seeks to extend CIBER observa- tions of the EBL throughout the near infrared into the optical, through measurements above Earth's atmosphere during a suborbital sounding rocket flight. The experiment has a LN2-cooled 28.5 cm Cassegrain telescope along with three optical paths and dichroic beamsplitters, which are used to obtain three wide-field images in six broad spectral bands between 0.5-2.0 μm. The three focal planes also contain linear variable filters (LVFs) which simultaneously take spectra with resolution R=20 across the same range. CIBER-2 is scheduled to y multiple times on a Black Brant IX sounding rocket from White Sands Missile Range in the New Mexico desert. For the first flight, scheduled for early 2021, we have completed a variety of pre-flight optical tests, which we use to make focus adjustments, spectral response measurements, and absolute photometric calibrations. In this paper, we describe the methods behind these tests and present their results for pre-flight performance evaluation. In particular, we present measurements of the PSF for each broad spectral band, along with absolute calibration factors for each band and the LVF. Through monochromator scans, we also measure the spectral responsivity of each LVF as a function of position.

We study the stellar halos of $0.2\lesssim z \lesssim 0.5$ galaxies with stellar masses spanning $M_*\sim 10^{10.5}$ to $10^{12}M_\odot$ (approximately $L_*$ galaxies at this redshift) using imaging data from the Cosmic Infrared Background Experiment (CIBER). A previous CIBER fluctuation analysis suggested that intra-halo light (IHL) contributes a significant portion of the near-infrared extragalactic background light (EBL), the integrated emission from all sources throughout cosmic history. In this work, we carry out a stacking analysis with a sample of $\sim$30,000 Sloan Digital Sky Survey (SDSS) photometric galaxies from CIBER images in two near-infrared bands (1.1 and 1.8 $��$m) to directly probe the IHL associated with these galaxies. We stack galaxies in five sub-samples split by brightness, and detect an extended galaxy profile, beyond the instrument point spread function (PSF), derived by stacking stars. We jointly fit a model for the inherent galaxy light profile, plus large-scale one- and two-halo clustering to measure the extended galaxy IHL. We detect non-linear one-halo clustering in the 1.8 $��$m band, at a level consistent with numerical simulations. Our results on the galaxy profile suggest that $\sim 50\%$ of the total galaxy light budget in our galaxy sample resides in the outskirts of the galaxies at $r > 10$ kpc. We describe this extended emission as IHL and and are able to study how this fraction evolves with cosmic time. These results are new in the near-infrared wavelength at the $L_*$ mass scale, and suggest that IHL has a significant contribution to the integrated galactic light, and to the amplitude of large-scale background fluctuations., 29 pages, 17 figures, accepted by ApJ

Examination of the opposition geometry properties show that Ryugu’s surface regolith is commensurate with laboratory studies of the photometric behavior of powdered carbonaceous chondrites. The regolith is consistent with a broad grain size distribution that contains a fine-grained component.

We present the AKARI far-infrared (FIR) all-sky maps and describe its characteristics, calibration accuracy and scientific capabilities. The AKARI FIR survey has covered 97% of the whole sky in four photometric bands, which cover continuously 50-180 micron with band central wavelengths of 65, 90, 140, and 160 microns. The data have been publicly released in 2014 (Doi et al., 2015) with improved data quality that have been achieved since the last internal data release (Doi et al., 2012). The accuracy of the absolute intensity is ≤10% for the brighter regions. Quantitative analysis of the relative intensity accuracy and its dependence upon spatial scan numbers has been carried out. The data for the first time reveal the whole sky distribution of interstellar matter with arcminute-scale spatial resolutions at the peak of dust continuum emission, enabling us to investigate large-scale distribution of interstellar medium in great detail. The filamentary structure covering the whole sky is well traced by the all-sky maps. We describe advantages of the AKARI FIR all-sky maps for the study of interstellar matter comparing to other observational data.

We present the status of development of the Superconducting Tunnel Junction (STJ) detector for the COsmic BAckground Neutrino Decay search (COBAND) experiment. The signal of the cosmic background neutrino decay is identified as a sharp cutoff at high energy end in a far-infrared region ranging from 15meV to 30meV in the energy spectrum of the photons from the space. The COBAND experiment will be done as rocket and satellite experiments in order to detect the far-infrared photons from the space. For the photon detector of the COBAND experiment, we are developing the STJ detectors. We will use a combination of the diffraction grating and the array of Nb/Al-STJ pixels with cryogenic amplifier for the rocket experiment, and use Hf-STJ without a grating for the future satellite experiment. The present status of the detector R&D and the experimental design for the COBAND experiment is reported.

著者人数: 152名(所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 羽澄, 昌史; 堂谷, 忠靖; 長谷部, 孝; 今田, 大皓; 満田, 和久; 坂井, 真一郎; 関本, 裕太郎; Tomida, T.; 辻本, 匡弘; Yamamoto, R.; 山崎, 典子), Accepted: 2019-01-18, 資料番号: SA1180402000

The Near-Earth Asteroid 162173 Ryugu (1999 JU3) was investigated by the JAXA Hayabusa2 mission from June 2018 to November 2019. The data acquired by NIRS3 spectrometer revealed a dark surface with a positive near-infrared spectral slope. In this work we investigated the spectral slope variations across the Ryugu surface, providing information about physical/chemical properties of the surface. We analysed the calibrated, thermally and photometrically corrected NIRS3 data, and we evaluated the spectral slope between 1.9 μm and 2.5 μm, whose values extend from 0.11 to 0.28 and the mean value corresponds to 0.163±0.022. Starting from the mean value of slope and moving in step of 1 standard deviation (0.022), we defined 9 “slope families”, the Low-Red-Slope families (LR1, LR2 and LR3) and the High-Red-Sloped families (HR1, HR2, HR3, HR4, HR5, HR6). The mean values of some spectral parameters were estimated for each family, such as the reflectance factor at 1.9 μm, the spectral slope, the depth of bands at 2.7 μm and at 2.8 μm. A progressive spectral reddening, darkening and weakening/narrowing of OH bands is observed moving from the LR families to the HR families. We concluded that the spectral variability observed among families is the result of the thermal metamorphism experienced by Ryugu after the catastrophic disruption of its parent body and space weathering processes that occurred on airless bodies as Ryugu, such as impact cratering and solar wind irradiation. As a consequence, the HR1, LR1, LR2 and LR3 families, corresponding to equatorial ridge and crater rims, are the less altered regions on Ryugu surface, which experienced the minor alteration and OH devolatilization; the HR2, HR3, HR4, HR5 families, coincident with floors and walls of impact craters, are the most altered areas, result of the three processes occurring on Ryugu. The strong reddening of the HR6 family (coincident with Ejima Saxum) is likely due to the fine-sized material covering the large boulder.

PURPOSE This research aimed to establish a diagnostic technique for breast cancer using nipple discharge (ND), with the objective of preventive diagnosis. ND has been proposed as a source of secreted proteomes that reflect early pathological changes in the ductal-lobular epithelial microenvironment, and could thus provide breast-specific cancer biomarkers that could be accessed noninvasively as a new clinical diagnostic technique. EXPERIMENTAL DESIGN Minute amounts of ND from patients with and without breast cancer (n = 19 and 12, respectively) were collected at the hospital and kept frozen until just before use. They were analyzed using high-pH RP peptide fractionations/low-pH RP 2D nano-LC/ESI-MS/MS. Biomarker candidates were also investigated using Western blot analysis and sandwich ELISA on ND and/or sera. RESULTS We found distinct tendencies in protein expression and three candidate breast cancer biomarkers (carbonic anhydrase 2, catalase, and peroxiredoxin-2) whose levels differed significantly between ND specimens from patients with and without breast cancer. CONCLUSIONS AND CLINICAL RELEVANCE These tendencies in protein expression and markers provide new ways to identify breast cancer patients. Therefore, RP/RP 2D LC/MS/MS analyses of ND and the above three markers are supported as a new breast cancer diagnostic technique.

We report observation of isotropic interplanetary dust (IPD) by analyzing the infrared (IR) maps of Diffuse Infrared Background Experiment (DIRBE) onboard the Cosmic Background Explorer (COBE) spacecraft. To search for the isotropic IPD, we perform new analysis in terms of solar elongation angle ($\epsilon$), because we expect zodiacal light (ZL) intensity from the isotropic IPD to decrease as a function of $\epsilon$. We use the DIRBE weekly-averaged maps covering $64^\circ \lesssim \epsilon \lesssim 124^\circ$ and inspect the $\epsilon$-dependence of residual intensity after subtracting conventional ZL components. We find the $\epsilon$-dependence of the residuals, indicating the presence of the isotropic IPD. However, the mid-IR $\epsilon$-dependence is different from that of the isotropic IPD model at $\epsilon \gtrsim 90^\circ$, where the residual intensity increases as a function of $\epsilon$. To explain the observed $\epsilon$-dependence, we assume a spheroidal IPD cloud showing higher density further away from the sun. We estimate intensity of the near-IR extragalactic background light (EBL) by subtracting the spheroidal component, assuming the spectral energy distribution from the residual brightness at $12\,{\rm \mu m}$. The EBL intensity is derived as $45_{-8}^{+11}$, $21_{-4}^{+3}$, and $15\pm3\,{\rm nWm^{-2}sr^{-1}}$ at $1.25$, $2.2$, and $3.5\,{\rm \mu m}$, respectively. The EBL is still a few times larger than integrated light of normal galaxies, suggesting existence of unaccounted extragalactic sources., Comment: Accepted for publication in The Astrophysical Journal

The extragalactic background light (EBL) is the integrated emission from all objects outside of the Milky Way galaxy. Imprinted by the history of stellar emission, the EBL in the near infrared traces light back to the birth of the first stars in the Universe and can allow tight constraints on structure formation models. Recent studies using data from the Spitzer Space Telescope and the first Cosmic Infrared Background ExpeRiment (CIBER-1) find that there are excess fluctuations in the EBL on large scales which have been attributed to either high redshift galaxies and quasars, or to stars that were stripped from their host galaxies during merging events. To help disentangle these two models, multi-wavelength data can be used to trace their distinctive spectral features. Following the success of CIBER-1, CIBER-2 is designed to identify the sources of the EBL excess fluctuations using data in six wavebands covering the optical and near infrared. The experiment consists of a cryogenic payload and is scheduled to launch four times on a recoverable sounding rocket. CIBER-2 has a 28.5 cm telescope coupled with an optics system to obtain wide-field images in six broad spectral bands between 0.5 and 2.5 μm simultaneously. The experiment uses 2048 × 2048 HAWAII-2RG detector arrays and a cryogenic star tracker. A prototype of the cryogenic star tracker is under construction for a separate launch to verify its performance and star tracking algorithm. The mechanical, optical, and electrical components of the CIBER-2 experiment will have been integrated into the payload by mid-2018. Here we present the final design of CIBER-2 and our team’s instrument characterization efforts. The design and analysis of the optical focus tests will be discussed. We also report on the performance of CIBER-2 support systems, including the cooling mechanisms and deployable components. Finally, we outline the remaining tasks required to prepare the payload for launch.

We present the development of a Superconducting Tunnel Junction detector using hafnium (Hf-STJ) as a far infrared single photon detector for COsmic BAckground Neutrino Decay search (COBAND) experiment. The photon energy spectrum from the decay of cosmic background neutrino is expected to have a sharp edge at the high energy end in a far-infrared region ranging from 14–25 meV in the cosmic infrared background and the overwhelming infrared foreground from the zodiacal emission. We are developing a Hf-STJ which is expected to have 2% energy resolution for a single photon of 25 meV. We have successfully produced a superconductor-insulator-superconductor structure using Hf. However, it is found to suffer from a large leakage current and needs modification of the Hf-STJ to reduce it. We have developed two new types of Hf-STJ: Hf-STJ with an Al layer and Hf-STJ with a new sputtering condition. The leakage current density of two new types of Hf-STJ becomes 16 times smaller than the old Hf-STJ and obtained a response to the visible light. Because of its large leakage current, further optimization is underway.

The outer solar system provides a unique, quiet vantage point from which to observe the universe around us, where measurements could enable several niche astrophysical science cases that are too difficult to perform near Earth. NASA's New Horizons mission comprises an instrument package that provides imaging capability from ultraviolet (UV) to near-infrared (near-IR) wavelengths with moderate spectral resolution located beyond the orbit of Pluto. A carefully designed survey with New Horizons can optimize the use of expendable propellant and the limited data telemetry bandwidth to allow several measurements, including a detailed understanding of the cosmic extragalactic background light; studies of the local and extragalactic UV background; measurements of the properties of dust and ice in the outer solar system; confirmation and characterization of transiting exoplanets; determinations of the mass of dark objects using gravitational microlensing; and rapid follow-up of transient events. New Horizons is currently in an extended mission designed to focus on Kuiper Belt science that will conclude in 2021. The astrophysics community has a unique, generational opportunity to use this mission for astronomical observation at heliocentric distances beyond 50 au in the next decade. In this paper, we discuss the potential science cases for such an extended mission, and provide an initial assessment of the most important operational requirements and observation strategies it would require. We conclude that New Horizons is capable of transformative science, and that it would make a valuable and unique asset for astrophysical science that is unlikely to be replicated in the near future., Comment: 28 pages, 10 figures, matches version published in PASP

We present the status of the development of Superconducting Tunnel Junction (STJ) detector with the cryogenic preamplifier as far-infrared single photon detector for the COsmic BAckground Neutrino Decay search (COBAND) experiment. The photon energy spectrum from the radiative decay of the cosmic background neutrino is expected to have a sharp cutoff at high energy end in a far-infrared region ranging from 15 meV to 30 meV. The detector is required to measure an individual photon energy with a sufficient energy resolution less than 2% for identifying the cutoff structure, and to be designed for a rocket or satellite experiment. We develop an array of Nb/Al-STJ pixels which can detect a single far-infrared photon delivered by a diffractive grating according to its wavelength. To achieve high signal-to-noise ratio of the STJ, we use a preamplifier made with the Silicon-on-Insulator (SOI) technique that can be operated around 0.3K. We have developed the Nb/Al-STJ with the SOI cryogenic preamplifier and have tested the detector performance around 0.3K.

The combination of cysteine-specific modifiers, iodoacetanilide (IAA) and (13)C7-labeled iodoacetanilide ((13)C7-IAA), has been applied to absolute quantification of proteins. The selected reaction monitoring (SRM) with the use of nano liquid chromatography/nanoelectrospray ionization ion trap mass spectrometry (nano LC/nano-ESI-IT-MS) analysis was applied to precise quantification of three commercial proteins. Good correlation was observed between the theoretical ratios and observed ratios for all these proteins both in a simple buffer solution and in a complex protein environment. Due to efficient tagging, this method does not require separate synthesis of isotope-labeled peptides for the SRM studies. Therefore, this method is expected to be a useful tool for proteomics research.

著者人数: 152名（所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 長谷部, 孝; 堂谷, 忠靖; 羽澄, 昌史; 今田, 大皓; 満田, 和久; 坂井, 真一郎; 関本, 裕太郎; Tomida, T.; 辻本, 匡弘; Yamamoto, R.; 山崎, 典子), Accepted: 2018-04-07, 資料番号: SA1180209000

We present a summary of our spectroscopic redshift catalogue of 404 sources in the AKARI Deep Field South (ADF-S). We have used the AAOmega spectrograph to target mid-infrared and far-infrared sources selected primarily from AKARI observations in this field for which we were able to obtain optical counterparts. Our sources with identified redshifts include 316 with Hα detections at z ≤ 0.345 and 15 sources at z > 1 with MgII or Lα emission lines. About 13% of our z ≤ 0.345 sources are dominated by active galactic nuclei (AGN) emission, although many show emission from both star formation and AGNs. The median Balmer decrement is 5.9. Ultra-luminous infrared galaxies (ULIRGs) were found only in the higher-redshift sources. Optical and near infrared data will be available shortly, enabling calibration of the line luminosities and spectral energy distribution (SED) fitting for these sources.

The results of a deep 20 cm radio survey at 20 cm are reported of the AKARI Deep Field South (ADF-S) near the South Ecliptic Pole (SEP), using the Australia Telescope Compact Array telescope, ATCA. The survey has 1 sigma detection limits ranging from 18.7--50 microJy per beam over an area of ~1.1 sq degrees, and ~2.5 sq degrees to lower sensitivity. The observations, data reduction and source count analysis are presented, along with a description of the overall scientific objectives, and a catalogue containing 530 radio sources detected with a resolution of 6.2" x 4.9". The derived differential source counts show a pronounced excess of sources fainter than ~1 mJy, consistent with an emerging population of star forming galaxies. Cross-correlating the radio with AKARI sources and archival data we find 95 cross matches, with most galaxies having optical R-magnitudes in the range 18-24 mag, and 52 components lying within 1" of a radio position in at least one further catalogue (either IR or optical). We have reported redshifts for a sub-sample of our catalogue finding that they vary between galaxies in the local universe to those having redshifts of up to 0.825. Associating the radio sources with the Spitzer catalogue at 24 microns, we find 173 matches within one Spitzer pixel, of which a small sample of the identifications are clearly radio loud compared to the bulk of the galaxies. The radio luminosity plot and a colour-colour analysis suggest that the majority of the radio sources are in fact luminous star forming galaxies, rather than radio-loud AGN. There are additionally five cross matches between ASTE or BLAST submillimetre galaxies and radio sources from this survey, two of which are also detected at 90 microns, and 41 cross-matches with submillimetre sources detected in the Herschel HerMES survey Public Data release.

We present the current status of the Cosmic Infrared Background ExpeRiment-2 (CIBER-2) project, whose goal is to make a rocket-borne measurement of the near-infrared Extragalactic Background Light (EBL), under a collaboration with U.S.A., Japan, South Korea, and Taiwan. The EBL is the integrated light of all extragalactic sources of emission back to the early Universe. At near-infrared wavelengths, measurement of the EBL is a promising way to detect the diffuse light from the first collapsed structures at redshift z∼10, which are impossible to detect as individual sources. However, recently, the intra-halo light (IHL) model is advocated as the main contribution to the EBL, and our new result of the EBL fluctuation from CIBER-1 experiment is also supporting this model. In this model, EBL is contributed by accumulated light from stars in the dark halo regions of low- redshift (z

Observational study on near-infrared (IR) scattering properties of interstellar dust grains has been limited due to its faintness. Using all-sky maps obtained from Diffuse Infrared Background Experiment (DIRBE), we investigate the scattering property from diffuse Galactic light (DGL) measurements at 1.25, 2.2, and 3.5 {\mu}m in addition to our recent analyses of diffuse near-IR emission (Sano et al. 2015; Sano et al. 2016). As a result, we first find that the intensity ratios of near-IR DGL to 100 {\mu}m emission increase toward low Galactic latitudes at 1.25 and 2.2 {\mu}m. The derived latitude dependence can be reproduced by a scattered light model of interstellar dust with a large scattering asymmetry factor g = of $0.8^{+0.2}_{-0.3}$ at 1.25 and 2.2 {\mu}m, assuming an infinite Galaxy disk as an illuminating source. The derived asymmetry factor is comparable to the values obtained in the optical, but several times larger than that expected from a recent dust model. Since possible latitude dependence of ultraviolet-excited dust emission at 1.25 and 2.2 {\mu}m would reduce the large asymmetry factor to the reasonable value, our result may indicate the first detection of such an additional emission component in the diffuse interstellar medium., Comment: 9 pages, 2 figures, 1 table, ApJ Letters accepted

Objective We developed a new volume rendering technique, the CT gastrography wall carving image (WC) technique, which provides a clear visualization of localized enhanced tumors in the gastric wall. We evaluated the diagnostic performance of the WC as an adjunct to conventional images in detecting early gastric cancer (EGC). Materials and methods Thirty-nine patients with 43 EGCs underwent contrast-enhanced MDCT gastrography for preoperative examination. Two observers independently reviewed the images under three different conditions: term 1 , Axial CT; term 2 , Axial CT, MPR and VE; and term 3 , Axial CT, MPR, VE and WC for the detection of EGC. The accuracy of each condition as reviewed by each of the two observers was evaluated by receiver operating characteristic analysis. Interobserver agreement was calculated using weighted- κ statistics. Results The best diagnostic performance and interobserver agreement were obtained in term 3 . The AUCs of the two observers for terms 1, 2, and 3 were 0.63, 0.73, and 0.84, and 0.57, 0.73, and 0.76, respectively. The interobserver agreement improved from fair at term 1 to substantial at term 3 . Conclusions The addition of WC to conventional MDCT display improved the diagnostic accuracy and interobserver reproducibility for the detection of ECG. WC represents a suitable alternative for the visualization of localized enhanced tumors in the gastric wall.

Amphiregulin (AREG), an EGF family protein, is synthesized as a type I transmembrane precursor (proAREG) and expressed on the cell surface with an extracellular EGF-like domain and an intracellular short cytoplasmic tail. The ectodomain shedding yields a soluble EGF receptor ligand (soluble AREG) which binds to EGF receptor (EGFR) and concomitantly induces migration of unshed proAREG from the plasma membrane to the nuclear envelope (NE). AREG is known to play a potential role in breast cancer and has been intensively investigated as an EGF receptor ligand, while the function of the NE-localized proAREG remains unknown. In this study we used a truncated mutant that mimics NE-localized proAREG without shedding stimuli to discriminate between the functions of NE-localized and plasma membrane-localized proAREG and demonstrate that NE-localized proAREG activates breast cancer cell migration, but suppresses cell growth. Moreover, the present study shows that induction of cell migration by NE-localized proAREG does not require the extracellular growth factor domain or EGF receptor function. Collectively these data demonstrate a novel function mediated by the intracellular domain of proAREG and suggest a significant role for NE-localized proAREG in driving human breast cancer progression.

Using all-sky maps obtained from COBE/DIRBE at 3.5 and 4.9 um, we present a reanalysis of diffuse sky emissions such as zodiacal light (ZL), diffuse Galactic light (DGL), integrated starlight (ISL), and isotropic residual emission including the extragalactic background light (EBL). Our new analysis, which includes an improved estimate of ISL using the Wide-field Infrared Survey Explorer (WISE) data, enabled us to find the DGL signal in a direct linear correlation between diffuse near-infrared and 100 um emission at high Galactic latitudes (|b| > 35 degree). At 3.5um, the high-latitude DGL result is comparable to the low-latitude value derived from the previous DIRBE analysis. In comparison with models of the DGL spectrum assuming a size distribution of dust grains composed of amorphous silicate, graphite, and polycyclic aromatic hydrocarbon (PAH), the measured DGL values at 3.5 and 4.9 um constrain the mass fraction of PAH particles in the total dust species to be more than ~ 2%. This was consistent with the results of Spitzer/IRAC toward the lower Galactic latitude regions. The derived residual emission of 8.9 +/- 3.4 nW m^{-2} sr^{-1} at 3.5 um is marginally consistent with the level of integrated galaxy light and the EBL constraints from the gamma-ray observations. The residual emission at 4.9 um is not significantly detected due to the large uncertainty in the ZL subtraction, same as previous studies. Combined with our reanalysis of the DIRBE data at 1.25 and 2.2 um, the residual emission in the near-infrared exhibits the Rayleigh-Jeans spectrum., ApJ accepted

We perform image stacking analysis of Sloan Digital Sky Survey (SDSS) photometric galaxies over the AKARI Far-Infrared Surveyor (FIS) maps at 65{\mu}m, 90{\mu}m, and 140{\mu}m. The resulting image profiles are decomposed into the central galaxy component (single term) and the nearby galaxy component (clustering term), as a function of the r-band magnitude, m_r of the central galaxy. We find that the mean far-infrared (FIR) flux of a galaxy with magnitude m_r is well fitted with f^s_{90{\mu}m}=13*10^{0.306(18-m_r)}[mJy]. The FIR amplitude of the clustering term is consistent with that expected from the angular-correlation function of the SDSS galaxies, but galaxy morphology dependence needs to be taken into account for a more quantitative conclusion. We also fit the spectral energy distribution of stacked galaxies at 65{\mu}m, 90{\mu}m, and 140{\mu}m, and derive a mean dust temperature of ~30K. This is consistent with the typical dust temperature of galaxies that are FIR luminous and individually detected., Comment: 19 pages, 17 figures, 3tables, accepted for publication in PASJ