A5049047187- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- CCD and CMOS Imaging Sensors
- Scientific Research and Discoveries
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Spectroscopy and Laser Applications
- Calibration and Measurement Techniques
- Plant Water Relations and Carbon Dynamics
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Atmospheric Ozone and Climate
- Advanced Measurement and Metrology Techniques
- Dark Matter and Cosmic Phenomena
Hokkaido Information University
2024
Tokyo University of Science
2017-2024
Liberal Arts University
2017-2020
Kwansei Gakuin University
2017-2020
Institute of Space and Astronautical Science
2012-2018
Japan Aerospace Exploration Agency
2012-2017
The Graduate University for Advanced Studies, SOKENDAI
2007-2012
National Astronomical Observatory of Japan
2011-2012
We present the discovery and mass measurement of cold, low-mass planet MOA-2009-BLG-266Lb, performed with gravitational microlensing method. This has a mp = 10.4 ± 1.7 M⊕ orbits star M⋆ 0.56 0.09 M☉ at semimajor axis AU an orbital period yrs. The host measurements are enabled by parallax effect, which is seen primarily in light curve distortion due to motion Earth. But analysis also demonstrates capability measure Deep Impact (or EPOXI) spacecraft heliocentric orbit. distance similar...
In this work, we investigate the dependence of covering factor (CF) active galactic nuclei (AGNs) on mid-infrared (MIR) luminosity and redshift. We constructed 12 22 μm functions (LFs) at 0.006 ⩽z ⩽ 0.3 using Wide-field Infrared Survey Explorer (WISE) data. Combining WISE catalog with Sloan Digital Sky (SDSS) spectroscopic data, selected 223,982 galaxies 25,721 for classification. then identified 16,355 AGNs 4683 by their optical emission lines cataloged classifications in SDSS. Following...
Abstract We report on the results of systematic infrared 2.5-5$\mu$m spectroscopy 45 nearby ultraluminous galaxies (ULIRGs) at $z \lt$ 0.3 using AKARI IRC. This paper investigates whether luminosities these ULIRGs are dominated by starburst activity, or alternatively, optically elusive buried active galactic nuclei (AGNs) energetically important, based strengths 3.3$\mu$m polycyclic aromatic hydrocarbon (PAH) emission and dust absorption features 3-4$\mu$m. Because IRC's spectroscopic...
We present high-resolution mid-infrared (MIR) imaging, nuclear spectral energy distributions (SEDs), and archival Spitzer spectra for 22 low-luminosity active galactic nuclei (LLAGNs; Lbol ≲ 1042 erg s−1). Infrared (IR) observations may advance our understanding of the accretion flows in LLAGNs, fate obscuring torus at low rates, and, perhaps, star formation histories these objects. However, while comprehensively studied higher-luminosity Seyferts quasars, IR properties LLAGNs have not yet...
X-ray and near-infrared ($J$-$H$-$K_{\rm s}$) observations of the Galactic black hole binary GX 339--4 in low/hard state were performed with Suzaku IRSF 2009 March. The spectrum 0.5--300 keV band is dominated by thermal Comptonization multicolor disk photons, a small contribution from direct component, indicating that inner almost fully covered hot corona an electron temperature $\approx$175 keV. Comptonizing has at least two optical depths, $\tau \approx 1,0.4$. Analysis iron-K line profile...
Abstract Observations of the molecular gas in galaxies are vital to understand evolution and star-forming histories galaxies. However, with maps their whole discs at sufficient resolution distinguish galactic structures severely lacking. Millimeter-wavelength studies a high angular across multiple lines transitions particularly needed, limiting our ability infer universal properties Hence, we conducted legacy project 45 m telescope Nobeyama Radio Observatory, called CO Multi-line Imaging...
We perform an MMT/Hectospec redshift survey of the North Ecliptic Pole Wide (NEPW) field covering 5.4 square degrees, and use it to estimate photometric redshifts for sources without spectroscopic redshifts. By combining 2572 newly measured from our with existing data literature, we create a large sample 4421 galaxies in NEPW field. Using this sample, 77755 band-merged catalog random forest model. The estimated are generally consistent redshifts, dispersion 0.028, outlier fraction 7.3%, bias...
Abstract We perform an MMT/Hectospec redshift survey of the North Ecliptic Pole Wide (NEPW) field covering 5.4 deg 2 and use it to estimate photometric redshifts for sources without spectroscopic redshifts. By combining 2572 newly measured from our with existing data literature, we create a large sample 4421 galaxies in NEPW field. Using this sample, 77,755 band-merged catalog random forest model. The estimated are generally consistent redshifts, dispersion 0.028, outlier fraction 7.3%, bias...
We present the results on millimeter interferometric observations of four luminous infrared galaxies (LIRGs), Arp 220, Mrk 231, IRAS 08572+3915, and VV 114, one Wolf-Rayet galaxy, He 2-10, using Nobeyama Millimeter Array (NMA). Both HCN(1-0) HCO+(1-0) molecular lines were observed simultaneously their brightness-temperature ratios derived. High-quality L-band (2.8-4.1 micron) spectra also obtained for LIRGs to better constrain energy sources deeply buried in dust gas. When combined with...
Abstract We present the photometric properties of a sample infrared (IR) bright dust-obscured galaxies (DOGs). Combining wide and deep optical images obtained with Hyper Suprime-Cam on Subaru Telescope all-sky mid-IR (MIR) taken Wide-Field Infrared Survey Explorer, we discovered 48 DOGs i − Ks > 1.2 [22] 7.0, where i, Ks, represent AB magnitude in i-band, Ks-band, 22 μm, respectively, GAMA 14 hr field (∼ 9 deg2). Among these objects, 31 65%) show power-law spectral energy...
Abstract We present the physical properties of AKARI sources without optical counterparts in images from Hyper Suprime-Cam (HSC) on Subaru telescope. Using infrared (IR) source catalog and HSC catalog, we select 583 objects that do not have North Ecliptic Pole wide survey field (∼5 deg 2 ). Because limiting magnitude is deep ( g AB ∼ 28.6), these are good candidates for extremely red star-forming galaxies (SFGs) and/or active galactic nuclei (AGNs), possibly at high redshifts. compile...
Aims. We aim to generate a catalogue of merging galaxies within the 5.4 sq. deg. North Ecliptic Pole over redshift range 0.0 < z 0.3. To do this, imaging data from Hyper Suprime-Cam are used along with morphological parameters derived these same data. Methods. The was generated using hybrid approach. Two neural networks were trained perform binary merger non-merger classifications: one for 0.15 and another ≤ 0.30. Each network image galaxy as input. that identified candidates by then...
We report high-resolution 12CO(J = 2–1), 13CO(J and 3–2) imaging of the Seyfert 1/starburst ring galaxy NGC 1097 with Submillimeter Array for purpose studying physical kinematic properties 1 kpc circumnuclear starburst ring. Individual star clusters as detected in Hubble Space Telescope map Paα line emission have been used to determine formation rate (SFR), are compared molecular gas. The has resolved into individual clumps at giant cloud association (GMA) scale 200–300 pc all three CO...
Aims. We present an 8-band (u*, g', r', i', z', Y, J, Ks) optical to NIR deep photometric catalog based on the observations made with MegaCam and WIRCam at CFHT, compute redshifts, zp in North Ecliptic Pole (NEP) region. Our provides us identify counterparts, for AKARI NIR/MIR sources. Results. The estimated 4sigma detection limits within 1" aperture radius are 26.7, 25.9, 25.1, 24.1 mag [AB] z'-bands 23.4, 23.0, 22.7 Ks-bands, respectively. There a total of 85797 sources band-merged...
(Abridged) We aim to study the evolution of dust attenuation in galaxies selected IR redshift range which they are known dominate star formation activity universe. The comparison with other measurements samples using different criteria will give us a global picture at work star-forming and its redshift. Using multiple filters IRC instrument, we more than 4000 from their rest-frame emission 8 microns, z~0.2 2$. built SEDs UV far-IR by adding data optical-NIR GALEX Herschel surveys. fit...
Abstract We present the results of infrared $L$-band (3–4$\ \mu$m) slit spectroscopy 30 PG QSOs at z$\lt$ 0.17, a representative sample local high-luminosity, optically selected AGNs. The 3.3$\ \mu$m polycyclic aromatic hydrocarbon (PAH) emission feature is used to probe nuclear ($\lt$ few kpc) starburst activity and investigate connections between AGNs starbursts in QSOs. PAH detected individual spectra 5/30 observed constructed composite spectrum PAH-undetected discerned presence therein....
Using star-forming galaxies sample in the nearby Universe (0.02<z<0.10) selected from SDSS (DR7) and GALEX all-sky survey (GR5), we present a new empirical calibration for predicting dust extinction of H-alpha-to-FUV flux ratio. We find that H-alpha (A(Ha)) derived with H-alpha/H-beta ratio (Balmer decrement) increases increasing H-alpha/UV as expected, but there remains considerable scatter around relation, which is largely dependent on stellar mass and/or equivalent width (EW(Ha)). At...
Context. We present the revised near- to mid-infrared catalogue of AKARI North Ecliptic Pole deep survey. The survey has unique advantage continuous filter coverage from 2 24 μm over nine photometric bands, but initial version leaves room for improvement in image analysis stage; original images are strongly contaminated by behaviour detector and optical system.
Several lines of argument support the existence a link between activity at nuclei galaxies, in form an accreting supermassive black hole, and star formation these galaxies. Radio jets have long been argued to be ideal mechanism that allows active galactic (AGNs) interact with their host galaxies affect formation. We use sample radio sources North Ecliptic Pole (NEP) field study nature this putative link, by means spectral energy distribution (SED) fitting. employ excellent coverage AKARI...
We present the results of a ground-based, high spatial resolution infrared 18 micron imaging study nearby luminous galaxies (LIRGs), using Subaru 8.2-m and Gemini South 8.1-m telescopes. The diffraction-limited images routinely achieved with these telescopes in Q-band (17-23 micron) allow us to investigate detailed distribution emission LIRGs. then whether surface brightnesses are modest, as observed starbursts, or so that active galactic nuclei (AGNs; brightness energy sources) indicated....
Abstract We present the results of $^{12}\textrm{C}$$\textrm{O}$(J = 1–0) and $^{13}\textrm{C}$$\textrm{O}$(J simultaneous mappings toward nearby barred spiral galaxy NGC 4303 as part CO Multi-line Imaging Nearby Galaxies (COMING) project. Barred galaxies often show lower star-formation efficiency (SFE) in their bar region compared to arms. In this paper, we examine relation between SFEs volume densities molecular gas n(H2) eight different regions within galactic disk with...
ABSTRACT We present a five-broad-band (grizy) photometric catalogue of Subaru/Hyper Suprime-Cam (HSC) optical imaging observations at around the North Ecliptic Pole (NEP) where AKARI infrared (IR) satellite conducted large survey (NEP-Wide survey). The cover almost all NEP-Wide field down to depth 28.1, 26.8, 26.3, 25.5, and 25.0 mag (5σ) grizy, respectively. five-band HSC contains about 2.6 million objects, 70 959 counterpart sources are identified in catalogue. added existing supplementary...
Aims. We present a catalog of optical and infrared (NIR) identifications (ID) X-ray sources in the AKARI North Ecliptic Pole (NEP) deep field detected with Chandra, covering ~0.34 deg 2 0.5–2 keV flux limits ranging between ~2–20 × 10 −16 erg s −1 cm −2 . Methods. The optical/NIR counterparts were taken from our Hyper Suprime Cam (HSC)/Subaru Wide-Field InfraRed Camera (WIRCam)/Canada–France–Hawaii Telescope (CFHT) data because these have much more accurate source positions due to their...
Much of the star formation is obscured by dust. For complete understanding cosmic history (CSFH), infrared (IR) census indispensable. AKARI carried out deep mid-infrared observations using its continuous 9-band filters in North Ecliptic Pole (NEP) field (5.4 deg$^2$). This took significant amount satellite's lifetime, $\sim$10\% entire pointed observations. By combining archival Spitzer (5 bands) and WISE (4 mid-IR photometry, we have, total, 18 band which most comprehensive photometric...
We examined radial variations in molecular-gas based star formation efficiency (SFE), which is defined as rate per unit molecular gas mass, for 80 galaxies selected from the CO Multi-line Imaging of Nearby Galaxies project (Sorai et al. 2019). The SFE individual are typically a factor 2 -- 3, suggests that nearly constant along galactocentric radius. found averaged $(1.69 \pm 1.1) \times 10^{-9}$ yr$^{-1}$, consistent with Leroy 2008 if we consider contribution helium to mass evaluation and...