Aims. We investigate the dynamical and physical structures of bright-rimmed clouds (BRCs) in a nearby H II region. We focused on carbon- and oxygen-bearing species that trace photon-dominated regions (PDRs) and warm molecular cloud surfaces in order to understand the effect of UV radiation from the exciting stars on the cloud structure. Methods. We mapped four regions around the most prominent BRCs at scales of 4-10 arcmin in the H II region IC 1396 (IC 1396A, B, D, and E) in [C II] 158 mu m with (up)GREAT on board SOFIA. IC 1396 is predominantly excited by an O6.5V star. Toward IC 1396A, we also observed [O I] 63 mu m and 145 mu m. We combined these observations with JCMT archive data, which provide the low-J transitions of CO, (CO)-C-13, and (CO)-O-18. All spectra are velocity-resolved. Results. The line profiles in the four mapped regions show a variety of velocity structures, which we investigated in detail for all observed emission lines. IC 1396B and D show clearly distinct velocity components that overlap along the line of sight. We find no clear sign of photoevaporating flows in the [C II] spectra, although the uncertainty in the location of the BRCs along the line of sight makes this interpretation inconclusive. Our analysis of the [C-13 II] emission in IC1396 A, which has the best signal-to-noise ratio, suggests that the [C II] is likely mostly optically thin. The heating efficiency, measured by the ([C II]+[O I] 63 mu m)/far-infrared intensity ratio, is higher in the northern part of IC 1396A than in the southern part, which may indicate a difference in the dust properties of the two areas. Conclusions. The complex velocity structures identified in the BRCs of IC 1396, which is apparently a relatively simple H II region, highlight the importance of velocity-resolved data for disentangling different components along the line of sight and thus facilitating a detailed study of the dynamics of the cloud. We also demonstrate that the optically thin [C-13 II] and [O I] 145 mu m emission lines are essential for a conclusive interpretation of the [C II] 158 mu m and [O I] 63 mu m line profiles.

This study endeavours to introduce an inventive hierarchical coupling methodology for evaluating the flight capabilities of polymer micromachined flapping-wing nano air vehicles (FWNAVs) using advanced computational tools. Furthermore, our objective is to provide a practical demonstration of FWNAVs in both tethered and airborne scenarios. These dual objectives represent the distinctive and pioneering aspects of this research. Such FWNAVs, which are insect-inspired robots, have a 2.5-dimensional structure. An FWNAV comprises a micro piezoelectric drive system and a pair of micro thin flexible wings. The drive system includes a micro transmission and a piezoelectric bimorph actuator. The flight performance of the designed FWNAV is evaluated using a hierarchical coupling approach, where the whole system is decomposed into a micro wing and a micro piezoelectric drive system. The coupling between these parts is modelled as one-way coupling and that between the micro wings and the surrounding air is modelled as strong coupling. In the one-way coupling analysis, nonlinear structural dynamic analysis is conducted for the micro piezoelectric drive system, where the dynamic response is transmitted to the micro wings via the Dirichlet boundary condition. In the strong coupling analysis, strongly coupled fluid-structure interaction analysis is conducted for the micro wings and the surrounding air to consider their strong coupling. The optimisation of flight performance is conducted using fluid-structure interaction analysis to achieve sufficient lift force to support the weight of an FWNAV. The design of a tethered and flyable FWNAV with a size of 10 mm or smaller is demonstrated. This FWNAV can be easily fabricated using polymer micromachining.

Abstract. We performed wave-optics-based numerical simulations at mid-infrared wavelengths to investigate how the presence or absence of entrance slits and optical aberrations affect the spectral resolving power R of a compact, high-spectral-resolving-power spectrometer containing an immersion-echelle grating. We tested three cases of telescope aberration (aberration-free, astigmatism, and spherical aberration), assuming the aberration budget of the Space Infrared Telescope for Cosmology and Astrophysics, which has a 20     μm wavelength diffraction limit. In cases with a slit, we found that the value of R at around 10 to 20  μm is approximately independent of the assumed aberrations, which is significantly different from the prediction of geometrical optics. Our results also indicate that diffraction from the slit improves R by enlarging the effective illuminated area on the grating window and that this improvement decreases at short wavelengths. For the slit-less cases, we found that the impact of aberrations on R can be roughly estimated using the Strehl ratio.

GREX-PLUS (Galaxy Reionization EXplorer and PLanetary Universe Spectrometer) is a new mission concept for ISAS/JAXA’s strategic L-class mission program in the 2030s. With a 1.2 m aperture, a 50 K cryogenic space telescope will have a < 1, 400 arcmin2 wide-field camera with 6 bands in the 2–10 μm wavelength range and a high-dispersion spectrometer with a wavelength resolution of < 30, 000 in the 10–18 μm band. The cryogenic infrared mission concept of GREX-PLUS is based on SPICA, exploiting the technical resources so far studied and developed, such as an active cooling system. The high-dispersion spectrometer of GREX-PLUS is based on the high-dispersion channel of the SPICA Mid-Infrared Instrument (SMI). The wide-field camera of GREX-PLUS is also based on previous concept studies for the ISAS/JAXA’s WISH mission concept. GREX-PLUS is a concept proposal for a Japan-led mission but international collaborations are also welcome.

SMI (SPICA Mid-infrared Instrument) is one of the three focal-plane science instruments for SPICA. SMI is the Japanese-led instrument proposed and managed by a university consortium. SMI covers the wavelength range from 10 to 36 μm with four separate channels: the low-resolution (R = 60 – 160) spectroscopy function for 17 – 36 μm, the broad-band (R = 5) imaging function at 34 μm, the mid-resolution (R = 1400 – 2600) spectroscopy function for 18 – 36 μm, and the high-resolution (R = 29000) spectroscopy function for 10 – 18 μm. In this presentation, we will show the latest design and specifications of SMI as a result of feasibility studies.

A partitioned iterative method based on hierarchical decomposition is proposed for providing numerical modeling and analysis of the piezoelectric energy harvester which is involved in coupled fluid-structure interaction, coupled electro-mechanical, and a controlling electrical circuit for piezoelectric structural applications in energy harvesting. This circuitintegrated piezoelectric structural application in energy harvesting surrounded by fluid media takes the form of natural four-way coupling of fluid flow, the structure, the electromechanical effect of the piezoelectric material, and the electrical circuit. This can be formulated exactly as a fluid-structure-piezoelectric-circuit interaction. These coupled four fields are hierarchically decomposed into the fluid-structure interaction, structure-piezoelectric interaction, and piezoelectric-circuit interaction interactions. Then these subsystems are decomposed into each field. The proposed finite element method enables to reuse of existing techniques because of its modularity. Furthermore, scalability to multiphysics and multisystem couplings is expected. There are some numerical approaches in particular monolithic coupling methods are studied which are computationally expensive and leads to an ill-conditioned coefficient matrix. Nevertheless, accurate modeling for predicting the characteristics of this four-way coupling using partitioned methods has not yet been developed. This method enables an investigation of piezoelectric structures in fluid with complex geometry, material composition, and attached electrical circuits to the harvester. A flexible piezoelectric bimorph harvester in the converging channel is analyzed to demonstrate the efficiency of the proposed method. The results indicate that the method captures the coupled effect accurately.

We present Spitzer/IRS mid-infrared spectral maps of the Galactic star-forming region M17 as well as IRSF/SIRIUS Brγ and Nobeyama 45-m/FOREST CO (J=1– 0) maps. The spectra show prominent features due to polycyclic aromatic hydrocarbons (PAHs) at wavelengths of 6.2, 7.7, 8.6, 11.3, 12.0, 12.7, 13.5, and 14.2 μm. We find that the PAH emission features are bright in the region between the HII region traced by Brγ and the molecular cloud traced by CO, supporting that the PAH emission originates mostly from photo-dissociation regions. Based on the spatially-resolved Spitzer/IRS maps, we examine spatial variations of the PAH properties in detail. As a result, we find that the interband ratio of PAH 7.7 μm/PAH 11.3 μm varies locally near M17SW, but rather independently of the distance from the OB stars in M17, suggesting that the degree of PAH ionization is mainly controlled by local conditions rather than the global UV environments determined by the OB stars in M17. We also find that the interband ratios of the PAH 12.0 μm, 12.7 μm, 13.5 μm, and 14.2 μm features to the PAH 11.3 μm feature are high near the M17 center, which suggests structural changes of PAHs through processing due to intense UV radiation, producing abundant edgy irregular PAHs near the M17 center. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Chuo-ku, Sagamihara 2525210, Japan Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065, Japan Nobeyama Radio Observatory, National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS), 462-2, Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305, Japan Department of Astronomical Science, School of Physical Science, SOKENDAI (The Graduate University for Advanced Studies), 2-21-1, Osawa, Mitaka, Tokyo 181-8588, Japan Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 3058577, Japan Graduate School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo 191-0042

In this study, a computational fluid­structure interaction (FSI) framework for characteristic deformations in insect's wings is proposed. The proposed framework consists of a pixel wing model using a structured shell finite element mesh, a projection method for the monolithic FSI monolithic equations using an algebraic splitting, and the FSI dynamic similarity law to measure dynamic similarity between model's and actual insect's flights. It is shown that the proposed framework can directly simulate passive feathering and cambering in insect's wings caused by the FSI, whose magnitudes are very close to those of actual insects.

In this era of spatially resolved observations of planet forming disks with ALMA and large ground-based telescopes such as the VLT, Keck and Subaru, we still lack statistically relevant information on the quantity and composition of the material that is building the planets, such as the total disk gas mass, the ice content of dust, and the state of water in planetesimals. SPICA is an infrared space mission concept developed jointly by JAXA and ESA to address these questions. The key unique capabilities of SPICA that enable this research are (1) the wide spectral coverage 10-220 micron, (2) the high line detection sensitivity of (1-2) 10-19 W m-2 with R 2000-5000 in the far-IR (SAFARI) and 10-20 W m-2 with R 29000 in the mid-IR (SMI, spectrally resolving line profiles), (3) the high far-IR continuum sensitivity of 0.45 mJy (SAFARI), and (4) the observing efficiency for point source surveys. This paper details how mid- to far-IR infrared spectra will be unique in measuring the gas masses and water/ice content of disks and how these quantities evolve during the planet forming period. These observations will clarify the crucial transition when disks exhaust their primordial gas and further planet formation requires secondary gas produced from planetesimals. The high spectral resolution mid-IR is also unique for determining the location of the snowline dividing the rocky and icy mass reservoirs within the disk and how the divide evolves during the build-up of planetary systems. Infrared spectroscopy (mid- to far-IR) of key solid state bands is crucial for assessing whether extensive radial mixing, which is part of our Solar System history, is a general process occurring in most planetary systems and whether extrasolar planetesimals are similar to our Solar System comets/asteroids. ... (abbreviated)

The piezoelectric energy harvesting devices for the conversion of mechanical vibration into electric energy via a flexible piezoelectric energy harvesting (FPED) structure have gained greater attention. Here, the large deformation of the FPED structure causes a strong interaction with the electric field (direct-piezoelectric effect) and structural field (inverse-piezoelectric effect), and vice-versa. Also an electrical circuit is attached to the electrodes covering the piezoelectric layers. This becomes a three-way coupling of the structure, the electromechanical effect of the piezoelectric material, and the electrical circuit. A mathematical and numerical model of the complex physical system of the involved multiphysics coupling characteristics in order to predict the operational properties and to increase the performance is very important. The presentation will discuss a partitioned coupling algorithm based hierarchical decomposition using finite element method for piezoelectric energy harvesting from structurepiezoelectric-circuit interaction. Results obtained with the finite element analysis are compared with the experimental results of PEHDs with base excitation reported in the literature.

The novelty of this study is the proposition of a design window (DW) search using the nonlinear dynamic simulation, and the finding of the DWs of the polymer micro transmission that satisfies the nonlinear and unsteady design requirements conflicting with each other simultaneously. Here, the DW is defined as an existing area of satisfactory solutions in a design parameter space, which is defined as the flapping frequency equivalent to small flies and the mass of the micro wing supported by the transmission design. Since this micro transmission is the key component of the flapping wing nano air vehicle (FWNAVs) which has a 2.5-D structure and is fabricated using polymer micromachining so proposed DWs will contribute to further miniaturizing FWNAVs.

With AKARI, we obtain the spatially-resolved near-infrared (2.5 – 5.0 μm) spectra for the nearby starburst galaxy M 82. These spectra clearly show the absorption features due to interstellar ices. Based on the spectra, we created the column density maps of H2O and CO2 ices. As a result, we find that the spatial distribution of H2O ice is significantly different from that of CO2 ice; H2O ice is widely distributed, while CO2 ice is concentrated near the galactic center. Our result for the first time reveals variations in CO2/H2O ice abundance ratio on a galactic scale, suggesting that the ice-forming interstellar environment changes within a galaxy. We discuss the cause of the spatial variations in the ice abundance ratio, utilizing spectral information on the hydrogen recombination Brα and Brβ lines and the polycyclic aromatic hydrocarbon 3.3 μm emission appearing in the AKARI near-infrared spectra. Subject headings: galaxies: individual (M 82) — galaxies: ISM — infrared: galaxies — ISM: molecules

We investigated the coronal properties of G-dwarf stars including the Sun over a wide range of X-ray luminosity L X (3 × 10 26 to 2 × 10 30 erg s −1 ). We analyzed the archival data of 10 X-ray bright ( L X > 10 28 erg s −1 ) G-dwarf stars to derive their emission measure (EM) and the coronal temperature ( T ) during the periods when no prominent stellar flares were observed. We attempted to explain the relation on the basis of our understanding of the present Sun: a steady corona model based on the so-called Rosner-Tucker-Vaiana (RTV) scaling laws and the observed power-law distribution function of surface magnetic features. We derived a theoretical scaling law of the EM– T relation for a star with multiple active regions, and applied it to the observations combined with data in the literature. We found that with the solar parameters, our scaling law seems to be consistent with the data of slowly rotating stars. However, more X-ray-bright stars are located well above the scaling law based on the solar parameter. The scaling law may explain the observations if those stars show a power-law distribution function of active regions with the same power-law index but a 10–100 times larger coefficient. This suggests that X-ray bright stars show more active regions for a given size than the Sun. Since our samples include rapidly rotating stars, we infer that the offset of the X-ray bright stars from the present Sun-based scaling law is due to the enhancement of the surface magnetic field generation by their rapid rotation.

Mid-infrared (IR) array detectors have been used for astronomical observations in space. However, the uniformities of their spectral response curves have not been investigated in detail, the understanding of which is important for spectroscopic observations using large array formats. We characterize the spectral responses of all the pixels in IR array detectors using a Fourier transform infrared spectrometer and cryogenic optics for measurements at high signal-to-noise ratios. We measured the spectral responses of the Si:As impurity band conduction (IBC) array, a flight back-up detector for AKARI /IRC. As a result, we find that the Si:As array has intrinsic variations in the spectral response along the row and column directions of the array. We also find that the cutoff wavelength of the Si:As IBC array depends on the intensity of the incident light.

We investigate properties of the interstellar medium (ISM) interacting with shocks around the Galactic supernova remnant IC443, using the results of near-infrared [FeII] and H2 line mapping with the IRSF/SIRIUS. In the present study, we newly performed H2 1-0 S(1) and 2-1 S(1) line mapping with the narrow-band filters tuned for these lines, covering the entire remnant (30'x35'). Combined with an [FeII] line map, our result shows that the H2 line emission is significantly detected in the southern region, while the [FeII] line emission is detected all over the remnant, suggesting that slow and fast shocks propagate through the southern region and the entire remnant, respectively. In particular, the H2 line emission is relatively strong compared to the [FeII] line emission in the southwestern region, where TeV gamma-ray emission is detected. As the strong H2 line emission indicates the dominance of the dense ISM, this result supports the scenario that the gamma-ray emission is likely to be produced through a heavy interaction between cosmic-ray protons and the dense ISM in the southwestern shell. We also find that the H2 and [FeII] line emissions show an anti-correlated spatial distribution in the same region, suggesting the presence of the clumpy ISM. Such a clumpy morphology of the ISM around IC443 may assist cosmic-ray protons to efficiently interact with large amounts of the ISM protons.

Galactic infrared (IR) bubbles, which can be seen as shell-like structures at mid-IR wavelengths, are known to possess massive stars within their shell boundaries. In our previous study (Hanaoka, 2019, PASJ, 71, 6), we expanded the research area to the whole Galactic plane ($0^{\circ } \le l \le 360^{\circ }$, $|b| \le 5^{\circ }$) and studied systematic differences in the shell morphology and the IR luminosity of the IR bubbles between inner and outer Galactic regions. In this study, utilizing high spatial-resolution data of AKARI and WISE in the mid-IR and Herschel in the far-IR, we investigate the spatial distributions of dust components around each IR bubble to discuss the relation between the star-formation activity and the dust properties of the IR bubbles. For the 247 IR bubbles studied in Hanaoka (2019, PASJ, 71, 6), 165 IR bubbles are investigated in this study, which have the Herschel data ($|b|\le 1^{\circ }$) and known distances. We created their spectral energy distributions on a pixel-by-pixel basis around each IR bubble, and decomposed them with a dust model consisting of polycyclic aromatic hydrocarbons (PAHs), hot dust, warm dust and cold dust. As a result, we find that the offsets of dust heating sources from the shell centers in inner Galactic regions are systematically larger than those in outer Galactic regions. Many of the broken bubbles in inner Galactic regions show large angles between the offset and the direction of the broken shell from the center. Moreover, the spatial variations of the PAH intensity and cold dust emissivity around the IR bubbles in inner Galactic regions are larger than those in outer Galactic regions. We discuss these results in light of the interstellar environments and the formation mechanism of the massive stars associated with the IR bubbles.