Edwin L. Turner

Characterization of the gaseous companion κ Andromedae b - New Keck and LBTI high-contrast observations

Context. We previously reported the direct detection of a low mass companion at a projected separation of 55 2 AU around the B9 type star Andromedae. The properties of the system (mass ratio, separation) make it a benchmark for the understanding of the formation and evolution of gas giant planets and brown dwarfs on wide-orbits. Aims. We present new angular di erential imaging (ADI) images of the system at 2.146 (Ks), 3.776 (L’), 4.052 (NB 4:05) and 4.78 m (M’) obtained with Keck/NIRC2 and LBTI/LMIRCam, as well as more accurate near-infrared photometry of the star with the MIMIR instrument. We aim to determine the near-infrared spectral energy distribution (SED) of the companion and use it to characterize the object. Methods. We used analysis methods adapted to ADI to extract the companion flux. We compared the photometry of the object to reference young/old objects and to a set of seven PHOENIX-based atmospheric models of cool objects accounting for the formation of dust. We used evolutionary models to derive mass estimates considering a wide range of plausible initial conditions. Finally, we used dedicated formation models to discuss the possible origin of the companion. Results. We derive a more accurate J = 15:86 0:21, H = 14:95 0:13, Ks = 14:32 0:09 mag for And b. We redetect the companion in all our high contrast observations. We confirm previous contrasts obtained at Ks and L’ band. We derive NB 4:05 = 13:0 0:2 and M 0 = 13:3 0:3 mag and estimate Log10(L=L ) = 3:76 0:06. Atmospheric models yield Te = 1900 +100 K. They do not set constrains on the surface gravity. “Hot-start” evolutionary models predict masses of 14 +25 MJup based on the luminosity and temperature estimates, and considering a conservative age range for the system (30 +120 Myr). “warm-start” evolutionary tracks constrain the mass to M 11MJup. Conclusions. The mass of Andromedae b mostly falls in the brown-dwarf regime, due to remaining uncertainties in age and mass-luminosity models. According to the formation models, disk instability in a primordial disk could account for the position and a wide range of plausible masses of And b.

HIGH-CONTRAST IMAGING OF INTERMEDIATE-MASS GIANTS WITH LONG-TERM RADIAL VELOCITY TRENDS

A radial velocity (RV) survey for intermediate-mass giants has been operated for over a decade at Okayama Astrophysical Observatory (OAO). The OAO survey has revealed that some giants show long-term linear RV accelerations (RV trends), indicating the presence of outer companions. Direct imaging observations can help clarify what objects generate these RV trends. We present the results of high-contrast imaging observations of six intermediate-mass giants with long-term RV trends using the Subaru Telescope and HiCIAO camera. We detected co-moving companions to γ Hya B ( 0.61 - 0.14 + 0.12 M ⊙ ) , HD 5608 B (0.10 ± 0.01M ⊙), and HD 109272 B (0.28 ± 0.06M ⊙). For the remaining targets(ι Dra, 18 Del, and HD 14067) we exclude companions more massive than 30-60 M Jup at projected separations of 1-7. We examine whether these directly imaged companions or unidentified long-period companions can account for the RV trends observed around the six giants. We find that the Kozai mechanism can explain the high eccentricity of the inner planets ι Dra b, HD 5608 b, and HD 14067 b.

Near-Infrared Polarimetry of the GG Tauri A Binary System

A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.

Constraining the Movement of the Spiral Features and the Locations of Planetary Bodies Within the AB Aur System

NASA Origins of Solar System program [NNX13AK17G, RTOP 12-OSS12-0045, NNG13PB64P]; MEXT Japan; Mitsubishi Foundation; [NSF-AST 1009203]; [1008440]; [1009314]

Near-IR Polarized Scattered Light Imagery of the DoAr 28 Transitional Disk

We present the first spatially resolved polarized scattered light H-band detection of the DoAr 28 transitional disk. Our two epochs of imagery detect the scattered light disk from our effective inner working angle of 0 double prime.10 (13 AU) out to 0double prime.50 (65 AU). This inner working angle is interior to the location of the systems gap inferred by previous studies using spectral energy distribution modeling (15 AU). We detected a candidate point source companion 1 double prime.08 northwest of the system; however, our second epoch of imagery strongly suggests that this object is a background star. We constructed a grid of Monte Carlo Radiative Transfer models of the system, and our best fit models utilize a modestly inclined (50 degrees), 0.01 solar mass disk that has a partially depleted inner gap from the dust sublimation radius out to approximately 8 AU. Subtracting this best fit, axi-symmetric model from our polarized intensity data reveals evidence for two small asymmetries in the disk, which could be attributable to a variety of mechanisms.

Orbital Characterization of GJ1108A System, and Comparison of Dynamical Mass with Model-derived Mass for Resolved Binaries

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 velocity measurements, an eccentric orbital solution of

Superclustering of Galaxies Traced by a Group of QSOS at Z = 1.1

e

Resolved Near-Infrared Image of Inner Cavity in GM Aur Transitional Disk

=0.63 is obtained, which might be induced by the Kozai-Lidov mechanism with a widely separated GJ1108B system. Combined with several observed properties, we confirm the system is indeed young. Columba is the most probable moving group, to which the GJ1108A system belongs, although its membership to the group has not been established. If the age of Columba is assumed for GJ1108A, the dynamical masses of both GJ1108Aa and GJ1108Ab (

Will LSST detect extra-solar planetesimals entering the Solar system?

M_{rm dynamical,GJ1108Aa}=0.72pm0.04 M_{odot}

A SEARCH FOR EXOSPHERIC COMPONENTS OF THE EXTRASOLAR PLANET HD209458b WITH SUBARU HDS(Extrasolar Planetary Systems, International Symposium on Origins of Life and Astrobiology)

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