Ionization of Polycyclic Aromatic Hydrocarbon Molecules around the Herbig Ae/Be environment

We present the results of mid-infrared N-band spectroscopy of the Herbig Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on board the 8m Subaru Telescope. The MWC1080 has a geometry such that the diffuse nebulous structures surround the central Herbig B0 type star. We focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like species, which are thought to be the carriers of the unidentified infrared (UIR) bands in such environments. A series of UIR bands at 8.6, 11.0, 11.2, and 12.7um is detected throughout the system and we find a clear increase in the UIR 11.0um/11.2um ratio in the vicinity of the central star. Since the UIR 11.0um feature is attributed to a solo-CH out-of-plane wagging mode of cationic PAHs while the UIR 11.2um feature to a solo-CH out-of-plane bending mode of neutral PAHs, the large 11.0um/11.2um ratio directly indicates a promotion of the ionization of PAHs near the central star.Comment: accepted for publication in Advances in Geoscienc

Crystalline Silicate Feature of the Vega-like star HD145263

We have observed the 8-13 $\mu$m spectrum (R$\sim$250) of the Vega-like star candidate HD145263 using Subaru/COMICS. The spectrum of HD145263 shows the broad trapezoidal silicate feature with the shoulders at 9.3 $\mu$m and 11.44 $\mu$m, indicating the presence of crystalline silicate grains. This detection implies that crystalline silicate may also be commonly present around Vega-like stars. The 11.44 $\mu$m feature is slightly shifted to a longer wavelength compared to the usual 11.2-3 $\mu$m crystalline forsterite feature detected toward Herbig Ae/Be stars and T Tauri stars. Although the peak shift due to the effects of the grain size can not be ruled out, we suggest that Fe-bearing crystalline olivine explains the observed peak wavelength fairly well. Fe-bearing silicates are commonly found in meteorites and most interplanetary dust particles, which originate from planetesimal-like asteroids. According to studies of meteorites, Fe-bearing silicate must have been formed in asteroidal planetesimals, supporting the scenario that dust grains around Vega-like stars are of planetesimal origin, if the observed 11.44 $\mu$m peak is due to Fe-bearing silicates.Comment: accepted for Publication in ApJ

Characterization and Improvement of the Image Quality of the Data Taken with the Infrared Camera (IRC) Mid-Infrared Channels onboard AKARI

Mid-infrared images frequently suffer artifacts and extended point spread functions (PSFs). We investigate the characteristics of the artifacts and the PSFs in images obtained with the Infrared Camera (IRC) onboard AKARI at four mid-infrared bands of the S7 (7{\mu}m), S11 (11{\mu}m), L15 (15{\mu}m), and L24 (24 {\mu}m). Removal of the artifacts significantly improves the reliability of the ref- erence data for flat-fielding at the L15 and L24 bands. A set of models of the IRC PSFs is also constructed from on-orbit data. These PSFs have extended components that come from diffraction and scattering within the detector arrays. We estimate the aperture correction factors for point sources and the surface brightness correction factors for diffuse sources. We conclude that the surface brightness correction factors range from 0.95 to 0.8, taking account of the extended component of the PSFs. To correct for the extended PSF effects for the study of faint structures, we also develop an image reconstruction method, which consists of the deconvolution with the PSF and the convolution with an appropriate Gaussian. The appropriate removal of the artifacts, improved flat-fielding, and image reconstruction with the extended PSFs enable us to investigate de- tailed structures of extended sources in IRC mid-infrared images.Comment: 35 pages, 15 figures, accepted for publication in PAS

Si and Fe depletion in Galactic star-forming regions observed by the Spitzer Space Telescope

We report the results of the mid-infrared spectroscopy of 14 Galactic star-forming regions with the high-resolution modules of the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope. We detected [SiII] 35um, [FeII] 26um, and [FeIII] 23um as well as [SIII] 33um and H2 S(0) 28um emission lines. Using the intensity of [NII] 122um or 205um and [OI] 146um or 63um reported by previous observations in four regions, we derived the ionic abundance Si+/N+ and Fe+/N+ in the ionized gas and Si+/O0 and Fe+/O0 in the photodissociation gas. For all the targets, we derived the ionic abundance of Si+/S2+ and Fe2+/S2+ for the ionized gas. Based on photodissociation and HII region models the gas-phase Si and Fe abundance are suggested to be 3-100% and <8% of the solar abundance, respectively, for the ionized gas and 16-100% and 2-22% of the solar abundance, respectively, for the photodissociation region gas. Since the [FeII] 26um and [FeIII] 23um emissions are weak, the high sensitivity of the IRS enables to derive the gas-phase Fe abundance widely in star-forming regions. The derived gas-phase Si abundance is much larger than that in cool interstellar clouds and that of Fe. The present study indicates that 3-100% of Si atoms and <22% of Fe atoms are included in dust grains which are destroyed easily in HII regions, probably by the UV radiation. We discuss possible mechanisms to account for the observed trend; mantles which are photodesorbed by UV photons, organometallic complexes, or small grains.Comment: 43 pages with 7 figures, accepted in Astrophysical Journa

Origins Space Telescope science drivers to design traceability

The Origins Space Telescope (Origins) concept is designed to investigate the creation and dispersal of elements essential to life, the formation of planetary systems, and the transport of water to habitable worlds and the atmospheres of exoplanets around nearby K-and M-dwarfs to identify potentially habitable-and even inhabited-worlds. These science priorities are aligned with NASA\u27s three major astrophysics science goals: How does the Universe work? How did we get here? and Are we alone? We briefly describe the science case that arose from the astronomical community and the science traceability matrix for Origins. The science traceability matrix prescribes the design of Origins and demonstrates that it will address the key science questions motivated by the science case

Positional variations among heterogeneous nucleosome maps give dynamical information on chromatin

Although nucleosome remodeling is essential to transcriptional regulation in eukaryotes, little is known about its genome-wide behavior. Since a number of nucleosome positioning maps in vivo have been recently determined, we examined if their comparisons might be used for obtaining a genome-wide profile of nucleosome remodeling. Using seven yeast maps, the local variability of nucleosomes, measured by the entropy, was significantly higher in a set of reported unstable nucleosomes. The binding sites of four transcription factors, known as the remodeling factors, were distinctively high both in entropy and linker ratio, whereas those of Yhp1, their potential inhibitor, showed the lowest values in both of them. Taken together, our map shows the general information of nucleosome dynamics reasonably well. The “nucleosome dynamics” map provides the new significant correlation with the degree of expression variety instead of their intensity. Furthermore, the associations with gene function and histone modification were also discussed here

Origins Space Telescope: Baseline mission concept

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid-and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins\u27 natural background-limited sensitivity

Advances on the structure of the R2TP/Prefoldin-like complex

Cellular stability, assembly and activation of a growing list of macromolecular complexes require the action of HSP90 working in concert with the R2TP/Prefoldin-like (R2TP/PFDL) co-chaperone. RNA polymerase II, snoRNPs and complexes of PI3-kinase-like kinases, a family that includes the ATM, ATR, DNA-PKcs, TRAPP, SMG1 and mTOR proteins, are among the clients of the HSP90-R2TP system. Evidence links the R2TP/PFDL pathway with cancer, most likely because of the essential role in pathways commonly deregulated in cancer. R2TP forms the core of the co-cochaperone and orchestrates the recruitment of HSP90 and clients, whereas prefoldin and additional prefoldin-like proteins, including URI, associate with R2TP, but their function is still unclear. The mechanism by which R2TP/PFLD facilitates assembly and activation of such a variety of macromolecular complexes is poorly understood. Recent efforts in the structural characterization of R2TP have started to provide some mechanistic insights. We summarize recent structural findings, particularly how cryo-electron microscopy (cryo-EM) is contributing to our understanding of the architecture of the R2TP core complex. Structural differences discovered between yeast and human R2TP reveal unanticipated complexities of the metazoan R2TP complex, and opens new and interesting questions about how R2TP/PFLD works

Origins Space Telescope: baseline mission concept

The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20  μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250  μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588  μm, making wide-area and deep spectroscopic surveys with spectral resolving power R  ∼  300, and pointed observations at R  ∼  40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural background-limited sensitivity

Machine-learning approaches to identify determining factors of happiness during the COVID-19 pandemic: retrospective cohort study

ObjectiveTo investigate determining factors of happiness during the COVID-19 pandemic.DesignObservational study.SettingLarge online surveys in Japan before and during the COVID-19 pandemic.ParticipantsA random sample of 25 482 individuals who are representatives of the Japanese population.Main outcome measureSelf-reported happiness measured using a 10-point Likert scale, where higher scores indicated higher levels of happiness. We defined participants with ≥8 on the scale as having high levels of happiness.ResultsAmong the 25 482 respondents, the median score of self-reported happiness was 7 (IQR 6-8), with 11 418 (45%) reporting high levels of happiness during the pandemic. The multivariable logistic regression model showed that meaning in life, having a spouse, trust in neighbours and female gender were positively associated with happiness (eg, adjusted OR (aOR) for meaning in life 4.17; 95% CI 3.92 to 4.43; p&lt;0.001). Conversely, self-reported poor health, anxiety about future household income, psychiatric diseases except depression and feeling isolated were negatively associated with happiness (eg, aOR for self-reported poor health 0.44; 95% CI 0.39 to 0.48; p&lt;0.001). Using machine-learning methods, we found that meaning in life and social capital (eg, having a spouse and trust in communities) were the strongest positive determinants of happiness, whereas poor health, anxiety about future household income and feeling isolated were important negative determinants of happiness. Among 6965 subjects who responded to questionnaires both before and during the COVID-19 pandemic, there was no systemic difference in the patterns as to determinants of declined happiness during the pandemic.ConclusionUsing machine-learning methods on data from large online surveys in Japan, we found that interventions that have a positive impact on social capital as well as successful pandemic control and economic stimuli may effectively improve the population-level psychological well-being during the COVID-19 pandemic