Publications (37)
Generator Contingency Modeling in Electric Energy Markets: Derivation of Prices via Duality Theory
N. G. Singhal, J. Kwon, K. W. Hedman
Traditional electric energy markets do not explicitly model generator contingencies. To improve the representation of resources and to enhance the modeling of uncertainty, existing…
The Structure of Pre-transitional Protoplanetary Disks I: Radiative Transfer Modeling of the Disk+Cavity in the PDS 70 system
Ruobing Dong, Jun Hashimoto, Roman Rafikov +49
Through detailed radiative transfer modeling, we present a disk+cavity model to simultaneously explain both the SED and Subaru H-band polarized light imaging for the pre-transition…
Oscillatory Non-collinear Magnetism Induced by Interfacial Charge Transfer in Metallic Oxide Superlattices
J. Hoffman, B. J. Kirby, J. Kwon +9
Interfaces between correlated complex oxides are promising avenues to realize new forms of magnetism that arise as a result of charge transfer, proximity effects and locally broken…
Orbital characterization of GJ1108A system, and comparison of dynamical mass with model-derived mass for resolved binaries
T. Mizuki, M. Kuzuhara, K. Mede +55
We report an orbital characterization of GJ1108Aab that is a low-mass binary system in pre-main-sequence phase. Via the combination of astrometry using adaptive optics and radial v…
Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
M. Kuzuhara, A. Fukui, J. H. Livingston +103
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observ…
SCExAO and GPI Band Photometry and Integral Field Spectroscopy of the Young Brown Dwarf Companion to HD 1160
Eugenio V. Garcia, Thayne Currie, Olivier Guyon +51
We present high signal-to-noise ratio, precise photometry and band (\gpiwave~m) spectroscopy of HD 1160 B, a young substellar companion discovered from the Gemini NIC…
Dust polarized emission observations of NGC 6334; BISTRO reveals the details of the complex but organized magnetic field structure of the high-mass star-forming hub-filament network
D. Arzoumanian, R. Furuya, T. Hasegawa +145
[Abridged] Filaments and hubs have received special attention recently thanks to studies showing their role in star formation. While the column density and velocity structures of b…
Direct Imaging Detection of Methane in the Atmosphere of GJ 504 b
M. Janson, T. Brandt, M. Kuzuhara +54
Most exoplanets detected by direct imaging so far have been characterized by relatively hot (> ~1000 K) and cloudy atmospheres. A surprising feature in some of their atmospheres ha…
Spiral Structure and Differential Dust Size Distribution in the LkHa 330 Disk
E. Akiyama, J. Hashimoto, H. B. Liu +58
Dust trapping accelerates the coagulation of dust particles, and thus it represents an initial step toward the formation of planetesimals. We report -band (1.6 um) linear polari…
SPICA - a large cryogenic infrared space telescope Unveiling the obscured Universe
P. R. Roelfsema, H. Shibai, L. Armus +66
Measurements in the infrared wavelength domain allow us to assess directly the physical state and energy balance of cool matter in space, thus enabling the detailed study of the va…
Nanostructural features degrading the performance of superconducting radio frequency niobium cavities revealed by TEM and EELS
Y. Trenikhina, A. Romanenko, J. Kwon +2
Nanoscale defect structure within the magnetic penetration depth of ~100nm is key to the performance limitations of niobium superconducting radio frequency (SRF) cavities. Using a…
Polarimetry and flux distribution in the debris disk around HD 32297
R. Asensio-Torres, M. Janson, J. Hashimoto +49
We present high-contrast angular differential imaging (ADI) observations of the debris disk around HD 32297 in H-band, as well as the first polarimetric images for this system in p…
New Techniques for High-Contrast Imaging with ADI: the ACORNS-ADI SEEDS Data Reduction Pipeline
Timothy D. Brandt, Michael W. McElwain, Edwin L. Turner +44
We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce hi…
New Strong Gravitational Lenses from the DESI Legacy Imaging Surveys Data Release 9
C. Storfer, X. Huang, A. Gu +14
We have conducted a search for strong gravitational lensing systems in the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys Data Release 9. This is the third pape…
The JCMT BISTRO Survey: Multi-wavelength polarimetry of bright regions in NGC 2071 in the far-infrared/submillimetre range, with POL-2 and HAWC+
L. Fanciullo, F. Kemper, K. Pattle +31
Polarized dust emission is a key tracer in the study of interstellar medium and of star formation. The observed polarization, however, is a product of magnetic field structure, dus…
Spiral Arms in the Asymmetrically Illuminated Disk of MWC 758 and Constraints on Giant Planets
C. A. Grady, T. Muto, J. Hashimoto +71
We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration…
A Statistical Analysis of SEEDS and Other High-Contrast Exoplanet Surveys: Massive Planets or Low-Mass Brown Dwarfs?
Timothy D. Brandt, Michael W. McElwain, Edwin L. Turner +50
We conduct a statistical analysis of a combined sample of direct imaging data, totalling nearly 250 stars. The stars cover a wide range of ages and spectral types, and include five…
Characterization of the gaseous companion κ Andromedae b: New Keck and LBTI high-contrast observations
M. Bonnefoy, T. Currie, G. -D. Marleau +64
We previously reported the direct detection of a low mass companion at a projected separation of 55+-2 AU around the B9 type star κ Andromedae. The properties of the system (mass…
Gradual pressure-induced enhancement of magnon excitations in CeCoSi
S. E. Nikitin, D. G. Franco, J. Kwon +6
CeCoSi is an intermetallic antiferromagnet with a very unusual temperature-pressure phase diagram: at ambient pressure it orders below K, while application o…
Toward superconducting critical current by design
I. A. Sadovskyy, Y. Jia, M. Leroux +14
We present the new paradigm of critical current by design. Analogous to materials by design, it aims at predicting the optimal defect landscape in a superconductor for targeted app…
Direct Imaging Discovery of a `Super-Jupiter' Around the late B-Type Star Kappa And
J. Carson, C. Thalmann, M. Janson +52
We present the direct imaging discovery of an extrasolar planet, or possible low-mass brown dwarf, at a projected separation of 55 +/- 2 AU (1.058 +/- 0.007 arcsec) from the B9-typ…
Probing the cold magnetized Universe with SPICA-POL (B-BOP)
Ph. André, A. Hughes, V. Guillet +53
SPICA, the cryogenic infrared space telescope recently pre-selected for a `Phase A' concept study as one of the three remaining candidates for ESA's fifth medium class (M5) mission…
Galaxy evolution studies with the SPace IR telescope for Cosmology and Astrophysics (SPICA): the power of IR spectroscopy
L. Spinoglio, A. Alonso-Herrero, L. Armus +65
IR spectroscopy in the range 12-230 micron with the SPace IR telescope for Cosmology and Astrophysics (SPICA) will reveal the physical processes that govern the formation and evolu…
Classification of the symmetry of photoelectron dichroism broken by light
Y. Ishida, D. Chung, J. Kwon +6
We investigate how the direction of polarized light can affect the dichroism pattern seen in angle-resolved photoemission spectroscopy. To this end, we prepared a sample composed o…
Unbiased large spectroscopic surveys of galaxies selected by SPICA using dust bands
H. Kaneda, D. Ishihara, S. Oyabu +27
The mid-infrared (IR) range contains many spectral features associated with large molecules and dust grains such as polycyclic aromatic hydrocarbons (PAHs) and silicates. These are…
SEEDS direct imaging of the RV-detected companion to V450 Andromedae, and characterization of the system
K. G. HeÅminiak, M. Kuzuhara, K. Mede +49
We report the direct imaging detection of a low-mass companion to a young, moderately active star V450 And, that was previously identified with the radial velocity method. The comp…
The Moving Group Targets of the SEEDS High-Contrast Imaging Survey of Exoplanets and Disks: Results and Observations from the First Three Years
Timothy D. Brandt, Masayuki Kuzuhara, Michael W. McElwain +52
We present results from the first three years of observations of moving group targets in the SEEDS high-contrast imaging survey of exoplanets and disks using the Subaru telescope.…
Near-Infrared Polarimetric Study of Near-Earth Object 252P/LINEAR: An Implication of Scattered Light from the Evolved Dust Particles
Y. G. Kwon, M. Ishiguro, J. Kwon +7
Aims. We aim to constrain the size and porosity of ejected dust particles from comet 252P/LINEAR and their evolution near the perihelion via near-infrared multiband polarimetry. A…
Subaru Imaging of Asymmetric Features in a Transitional Disk in Upper Scorpius
S. Mayama, J. Hashimoto, T. Muto +52
We report high-resolution (0.07 arcsec) near-infrared polarized intensity images of the circumstellar disk around the star 2MASS J16042165-2130284 obtained with HiCIAO mounted on t…
Discovery of a Disk Gap Candidate at 20 AU in TW Hydrae
E. Akiyama, T. Muto, N. Kusakabe +53
We present a new Subaru/HiCIAO high-contrast H-band polarized intensity (PI) image of a nearby transitional disk associated with TW Hydrae. The scattered light from the disk was de…
The Structure of Pre-transitional Protoplanetary Disks. II. Azimuthal Asymmetries, Different Radial Distributions of Large and Small Dust Grains in PDS~70
J. Hashimoto, T. Tsukagoshi, J. M. Brown +54
The formation scenario of a gapped disk, i.e., transitional disk, and its asymmetry is still under debate. Proposed scenarios such as disk-planet interaction, photoevaporation, gra…
Imaging Discovery of the Debris Disk Around HIP 79977
C. Thalmann, M. Janson, E. Buenzli +47
We present Subaru/HiCIAO H-band high-contrast images of the debris disk around HIP 79977, whose pres- ence was recently inferred from an infrared excess. Our images resolve the dis…
Work function seen with sub-meV precision through laser photoemission
Y. Ishida, J. K. Jung, M. S. Kim +7
Electron emission can be utilised to measure the work function of the surface. However, the number of significant digits in the values obtained through thermionic-, field- and phot…
Mode identification in the high-amplitude δ Scuti star V2367 Cyg
C. Ulusoy, T. Gülmez, I. Stateva +14
We report on a multi-site photometric campaign on the high-amplitude Scuti star V2367 Cyg in order to determine the pulsation modes. We also used high-dispersion spectroscopy…
Modeling the accretion disk around the high-mass protostar GGD 27-MM1
N. Añez-Lopez, M. Osorio, G. Busquet +9
Recent high-angular resolution (40 mas) ALMA observations at 1.14 mm resolve a compact (R~200 au) flattened dust structure perpendicular to the HH 80-81 jet emanating from the GGD…
The VVV Templates Project. Towards an Automated Classification of VVV Light-Curves. I. Building a database of stellar variability in the near-infrared
R. Angeloni, R. Contreras Ramos, M. Catelan +50
Context. The Vista Variables in the VÃa Láctea (VVV) ESO Public Survey is a variability survey of the Milky Way bulge and an adjacent section of the disk carried out from 2010 on…
Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504
M. Kuzuhara, M. Tamura, T. Kudo +54
Several exoplanets have recently been imaged at wide separations of >10 AU from their parent stars. These span a limited range of ages (<50 Myr) and atmospheric properties, with te…