A5021419562- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Gamma-ray bursts and supernovae
- Optical measurement and interference techniques
- Optical Systems and Laser Technology
- History and Developments in Astronomy
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Spacecraft Design and Technology
- Planetary Science and Exploration
- Relativity and Gravitational Theory
- Advanced optical system design
- Advanced Measurement and Metrology Techniques
- Remote Sensing in Agriculture
- Geophysics and Gravity Measurements
- Inertial Sensor and Navigation
- Astrophysical Phenomena and Observations
- Black Holes and Theoretical Physics
University of Hawaii System
2004-2015
Max Planck Institute for Astronomy
2013
University of Hawaiʻi at Mānoa
2003-2010
University of Hawaii–West Oahu
2010
University of Hawaii at Hilo
2005-2010
Gemini South Observatory
2009
University of Arizona
2009
Michigan Technological University
1997-2002
Danbury Hospital
1991-1995
University of Pennsylvania
1978-1994
We report results of a direct imaging survey for giant planets around 80 members the Beta Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part Gemini NICI Planet-Finding Campaign. For this sample, we obtained median contrasts \Delta H=13.9 mag at 1" in combined CH4 narrowband ADI+SDI mode H=15.1 2" H-band ADI mode. found numerous (>70) candidate companions our images. Some these candidates were rejected common-proper motion using archival data; reobserved...
view Abstract Citations (234) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Hot spots on neutron stars - The near-field gravitational lens Pechenick, K. R. ; Ftaclas, C. Cohen, J. M. A simple model is presented for including gravity in the light curves of slowly rotating whose emission confined to circular antipodal polar caps. Both thermal and near cases are condidered. It found that hot caps typical star parameters essentially flat as a...
We report the discovery of a tight substellar companion to young solar analog PZ Tel, member Beta Pictoris moving group observed with high contrast adaptive optics imaging as part Gemini NICI Planet-Finding Campaign. The was detected at projected separation 16.4 +/- 1.0 AU (0.33 0.01") in April 2009. Second-epoch observations May 2010 demonstrate that is physically associated and shows significant orbital motion. Monte Carlo modeling constrains orbit Tel B eccentricities > 0.6. near-IR...
We present the discovery of a wide (67 AU) substellar companion to nearby (21 pc) young solar-metallicity M1 dwarf CD−35 2722, member ≈100 Myr AB Doradus association. Two epochs astrometry from NICI Planet-Finding Campaign confirm that 2722 B is physically associated with primary star. Near-IR spectra indicate spectral type L4±1 moderately low surface gravity, making it one coolest companions found date. The absorption lines and near-IR continuum shape agree especially well dusty field L4.5...
We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf planetary companions as part the Gemini NICI Planet-Finding Campaign. Our survey represents largest, deepest planets around high-mass (~1.5-2.5 M_sun) conducted date includes planet hosts beta Pic Fomalhaut. obtained follow-up astrometry all candidate within 400 AU projected separation in uncrowded fields identified new low-mass HD 1160 HIP 79797. found that previously known young companion...
We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. achieved median H-band contrasts 12.4 mag at 0.5" and 14.1 1" separation. Follow-up observations 66 candidates with projected separation < 500 AU show that all them are background objects. To establish statistical constraints on underlying planet population based our data, we developed new Bayesian formalism incorporates (1) non-detections,...
We present the first ground-based CCD ($\lambda < 1\mu$m) image of an extrasolar planet. Using MagAO's VisAO camera we detected giant planet (EGP) $\beta$ Pictoris b in $Y$-short ($Y_S$, 0.985 $\mu$m), at a separation $0.470 \pm 0.010''$ and contrast $(1.63 0.49) \times 10^{-5}$. This detection has signal-to-noise ratio 4.1, with empirically estimated upper-limit on false alarm probability 1.0%. also new photometry from NICI instrument Gemini-South telescope, $CH_{4S,1\%}$ ($1.58$ $\mu m$),...
We report the discovery by Gemini NICI Planet-Finding Campaign of two low-mass companions to young A0V star HD 1160 at projected separations 81 +/- 5 AU (HD B) and 533 25 C). VLT images system taken over a decade for purpose using A as photometric calibrator confirm that both are physically associated. By comparing members moving groups open clusters with well-established ages, we estimate an age 50 (+50,-40) Myr ABC. While UVW motion does not match any known group, small magnitude space...
We present new astrometry for the young (12--21 Myr) exoplanet beta Pictoris b taken with Gemini/NICI and Magellan/MagAO instruments between 2009 2012. The high dynamic range of our observations allows us to measure relative position Pic respect its primary star greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find planet has an orbital semi-major axis 9.1 (+5.3, -0.5) AU eccentricity <0.15 at 68% confidence (with 95% intervals 8.2--48 0.00--0.82...
We present the coronagraphic and adaptive optics performance of Gemini-South Near-Infrared Coronagraphic Imager (NICI). NICI includes a dual-channel imager for simultaneous spectral difference imaging, dedicated 85-element curvature system, built-in Lyot coronagraph. It is specifically designed to survey image large extra-solar gaseous planets on Gemini Observatory 8-meter telescope in Chile. on-sky individual subsystems along with end-to-end contrast curve. These are compared our model...
We present J, H, CH_4 short (1.578 micron), long (1.652 micron) and K_s-band images of the dust ring around 10 Myr old star HR 4796 A obtained using Near Infrared Coronagraphic Imager (NICI) on Gemini-South 8.1 meter Telescope. Our clearly show for first time position relative to its circumstellar thanks NICI's translucent focal plane occulting mask. employ a Bayesian Markov Chain Monte Carlo method constrain offset vector between two. The resulting probability distribution shows that center...
We report here the highest resolution near-IR imaging to date of HD 141569A disc taken as part NICI Science Campaign. recover 4 main features in images 141569 discovered previous HST imaging: 1) an inner ring / spiral feature. Once deprojected, this feature does not appear circular. 2) outer which is considerably brighter on western side compared eastern side, but looks fairly circular deprojected image. 3) additional arc-like between and only evident east side. In image, appears complete...
The parallax and astrometric orbit of Procyon have been redetermined from PDS measurements over 250 photographic plates spanning 83 years, with roughly 600 exposures used in the solution. These data are combined two modern primary–white dwarf separation, one utilizing a ground-based coronagraph, other, Planetary Camera (PC) Hubble Space Telescope. Together parallax, these yield new estimates component masses. derived masses 1.497 ± 0.037 M⊙ for primary 0.602 0.015M⊙ white secondary. mass...
We present high-contrast image processing techniques used by the Gemini NICI Planet-Finding Campaign to detect faint companions bright stars. The Near-Infrared Coronographic Imager (NICI) is an adaptive optics instrument installed on 8 m South telescope, capable of angular and spectral difference imaging specifically designed exoplanets. data pipeline achieves median contrasts 12.6 mag at 05 14.4 1'' separation, for a sample 45 stars (V = 4.3–13.9 mag) from early phase campaign. also novel...
We present ground-based near-infrared (H-band) imaging of the circumstellar disk around nearby classical T Tauri star TW Hydrae.The scattered-light image shows a face-on with radius 4Љ (corresponding to 225 AU) and morphology that agrees recent images from Hubble Space Telescope Very Large Array.The best-fit power-law for disk's radial surface brightness profile obeys law .We use ourr published continuum flux densities derive properties simple model emission flat disk.The values mass inner...
The Near-Infrared Coronagraphic Imager (NICI) is a high-contrast AO imager at the Gemini South telescope. camera includes coronagraphic mask and dual channel imaging for Spectral Differential Imaging (SDI). instrument can also be used in fixed Cassegrain Rotator mode Angular (ADI). While coronagraphy, SDI, ADI have been applied before direct searches exoplanets. NICI represents first time that these 3 techniques combined. We present preliminary commissioning data using show combining SDI...
Our team is carrying out a multi-year observing program to directly image and characterize young extrasolar planets using the Near-Infrared Coronagraphic Imager (NICI) on Gemini-South 8.1-meter telescope. NICI first instrument large telescope designed from outset for high-contrast imaging, comprising high-performance curvature adaptive optics (AO) system with simultaneous dual-channel coronagraphic imager. Combined state-of-the-art AO methods data processing, typically achieves ≈2 magnitudes...
The University of Florida is developing a mid-infrared camera for the 10.4-meter Gran Telescopio CANARIAS. CanariCam has four science modes and two engineering modes, which use same 320 x 240-pixel, arsenic-doped silicon, blocked-impurity-band detector from Raytheon. Each mode can be remotely selected quickly during an observing sequence. pixel scale 0.08 arcsec, resulting in Nyquist sampling diffraction-limited point-spread-function at 8 μm, shortest wavelength optimized. total available...
view Abstract Citations (57) References (48) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity distribution of Virgo cluster galaxies. Ftaclas, C. ; Fanelli, M. N. Struble, F. Several effects the general population Local Supercluster on observed properties Cluster are analyzed. Two subgroups identified in field that most likely beyond distance. Combined with an intrusion W cloud into cluster, this clumped component accounts for about 9 percent galaxies...
Diffraction from secondary mirror spiders can significantly affect the image quality of optical telescopes; however, these effects vary drastically with chosen image-quality criterion. Rigorous analytical calculations diffraction are often unwieldy, and virtually all commercially available design analysis codes that have a diffraction-analysis capability based on numerical Fourier-transform algorithms frequently lack an adequate sampling density to model narrow spiders. The spider Strehl...
From 2008 December to 2012 September, the NICI (Near-Infrared Coronagraphic Imager at Gemini-South 8.1-m) Planet-Finding Campaign (Liu et al. 2010) obtained deep, high-contrast AO imaging of a carefully selected sample over 200 young, nearby stars. In course campaign, we discovered four co-moving brown dwarf companions: PZ Tel B (36±6 M<sub>Jup</sub>, 16.4±1.0 AU), CD-35 2722B (31±8 67±4 HD 1160B (33<sup>+12</sup><sub> -9</sub> 81± and HIP 79797Bb...
We examine relations between shape, richness, and velocity dispersion for a sample of 350 clusters galaxies all morphologies, including those with visible substructure. For our the apparent shape is correlated Abell [ApJS, 3,211(1958)] richness in sense that poor, low are flatter mean than their richer, higher counterparts. These characteristics also exhibited by x-ray emitting gas. There virtually no highly flattened having high or dispersions sample. find variation too steep to be assigned...
The Hokupa'a-85 curvature adaptive optics system components have been adapted to create a new AO-corrected coud´e instrument at the 3.67m Advanced Electro-Optical System (AEOS) telescope. This optical path is designed deliver an f/40 diffraction-limited focus wavelengths longer than 800nm. A EMCCD-based dual-beam imaging polarimeter called InnoPOL has and presently being installed behind this corrected beam. flexible platform for optimizing polarimetric performance using commercial solutions...