bluuebunny/crossref_metadata_2025_split huggingface dataset:
Results of the NaCo Large Program: probing the occurrence of exoplanets and brown dwarfs at wide orbit
Authors: Vigan A. , Chauvin G. , Bonavita M. , Desidera S. , Bonnefoy M. , Mesa D. , Beuzit J.-L. , Augereau J.-C. , Biller B. , Boccaletti A. , Brugaletta E. , Buenzli E. , Carson J. , Covino E. , Delorme P. , Eggenberger A. , Feldt M. , Hagelberg J. , Henning T. , Lagrange A.-M. , Lanzafame A. , Ménard F. , Messina S. , Meyer M. , Montagnier G. , Mordasini C. , Mouillet D. , Moutou C. , Mugnier L. , Quanz S. P. , Reggiani M. , Ségransan D. , Thalmann C. , Waters R. , Zurlo A. 
Published: January 2014

AbstractOver the past decade, a growing number of deep imaging surveys have started to provide meaningful constraints on the population of extrasolar giant planets at large orbital separation. Primary targets for these surveys have been carefully selected based on their age, distance and spectral type, and often on their membership to young nearby associations where all stars share common kinematics, photometric and spectroscopic properties. The next step is a wider statistical analysis of the frequency and properties of low mass companions as a function of stellar mass and orbital separation. In late 2009, we initiated a coordinated European Large Program using angular differential imaging in the H band (1.66 μm) with NaCo at the VLT. Our aim is to provide a comprehensive and statistically significant study of the occurrence of extrasolar giant planets and brown dwarfs at large (5-500 AU) orbital separation around ~150 young, nearby stars, a large fraction of which have never been observed at very deep contrast. The survey has now been completed and we present the data analysis and detection limits for the observed sample, for which we reach the planetary-mass domain at separations of ≳50 AU on average. We also present the results of the statistical analysis that has been performed over the 75 targets newly observed at high-contrast. We discuss the details of the statistical analysis and the physical constraints that our survey provides for the frequency and formation scenario of planetary mass companions at large separation.
Quick-MESS: A fast statistical tool for Exoplanet Imaging Surveys
Authors: Bonavita Mariangela , De Mooij Ernst , Jayawardhana Ray , Gratton Raffaele 
Published: January 2014

AbstractSeveral tools have been developed for the analysis of the results of direct imaging exoplanet surveys, mostly using a combination of Monte-Carlo simulations or a Bayesian approach. Here we present a novel approach to the statistical analysis of Direct Imaging surveys, called Quick-MESS, which allows for a much faster and flexible analysis.
GRAPHIC: The Geneva Reduction and Analysis Pipeline for High-contrast Imaging of planetary Companions
Authors: Hagelberg Janis , Ségransan Damien , Udry Stéphane , Wildi François 
Published: January 2014

AbstractWe present a new analysis and reduction pipeline for the detection of planetary companions using Angular Differential Imaging. The pipeline uses Fourier transforms for image shifting and rotation in order to achieve very low signal loss. Furthermore it is parallelised in order to run on computer clusters of up to 1024 cores. The pipeline was developed in Geneva for the ongoing direct imaging campaign for stars with radial velocity drifts in the HARPS and CORALIE radial-velocity planet-search surveys. In addition to that, a disk mode has been implemented in the context of observations of the protoplanetary disk around HD142527.
TLOCI: A Fully Loaded Speckle Killing Machine
Authors: Marois Christian , Correia Carlos , Véran Jean-Pierre , Currie Thayne 
Published: January 2014

AbstractA new high-contrast imaging subtraction algorithm (TLOCI) is presented to maximize a planet signal-to-noise ratio. The technique uses an input spectrum and template PSFs to optimize the reference image coefficient determination to minimize the flux contamination via self-subtraction (thus maximizing its throughput wavelength per wavelength) of any planet that have a similar spectrum to the template spectrum in the image, while trying, at the same time, to maximize the speckle noise subtraction. The optimization is performed by a correlation matrix conditioning. Using laboratory Gemini Planet Imager data, the new algorithm is shown to be superior to the simple/double difference, polynomial fit and original LOCI algorithm.
Exploring exoplanetary systems beyond 1AU with WFIRST
Authors: Penny Matthew T. , Gaudi B. Scott 
Published: January 2014

AbstractThe Wide Field InfraRed Survey Telescope (WFIRST) was the top ranked large space mission of the New Worlds, New Horizons Decadal Survey, and is currently under active study by NASA. Its primary instrument will be a large-format high-resolution near-infrared imager and slitless spectrometer. A primary goal of WFIRST will be to perform a high-cadence microlensing survey of the Galactic bulge to search for low-mass exoplanets beyond the ice line. We highlight some of the expected results of the WFIRST exoplanet survey. For example, the survey will probe the abundance of Earth-mass planets from less than 1 AU outwards, including free-floating planets. In its peak sensitivity range of ~2–5 AU, WFIRST will be sensitive to planets with masses lower than Mercury, and even down to the mass of Ganymede. Overall, WFIRST is expected to detect several thousand bound planets, in addition to several thousand free-floating planets. WFIRST will complete the exoplanet census begun by Kepler, enabling an unprecedented understanding of planetary systems and their formation.
Campaign Scheduling and Analysis for the Gemini Planet Imager
Authors: Savransky Dmitry , Macintosh Bruce A. , Graham James , Konopacky Quinn M. ,   the GPI science team
Published: January 2014

AbstractThe Gemini Planet Image (GPI) is a new, high-contrast, exoplanet-imaging, facility instrument for the Gemini South observatory, scheduled to begin science observations in 2014. The GPI Exoplanet Survey (GPIES) has been awarded 890 hours to image and spectrally and polarimetrically characterize young, giant planets within 100 parsecs of the solar system. In preparation for the survey, we have developed a framework for simulating GPI observations and generating end-to-end survey simulations. We present new extensions to this modeling effort and our latest results. We discuss systematic methods for scheduling the survey to ensure that the population of discovered planets is useful in constraining formation models and possibly distinguishing between gravitational collapse and core accretion as the primary formation mechanism.
The VLTi/PIONIER survey of southern TTauri disks
Authors: Anthonioz Fabien , Ménard F. , Pinte C. , Thi W-F. , Lebouquin J.-B. , Berger J.-P. , Benisty M. , Absil O. , Duchène G. , Lazareff B. , Malbet F. , Millan-Gabet R. , Traub W. , Zins G. 
Published: January 2014

AbstractStudying the inner regions of protoplanetary disks (1-10 AU) is of importance to understand the formation of planets and the accretion process feeding the forming central star. Herbig AeBe stars are bright enough to be routinely observed by Near IR interferometers. The data for the fainter T Tauri stars is much more sparse. In this contribution we present the results of our ongoing survey at the VLTI. We used the PIONIER combiner that allows the simultaneous use of 4 telescopes, yielding 6 baselines and 3 independent closure phases at once. PIONIER's integrated optics technology makes it a sensitive instrument. We have observed 22 T Tauri stars so far, the largest survey for T Tauri stars to this date.Our results demonstrate the very significant contribution of an extended component to the interferometric signal. The extended component is different from source to source and the data, with several baselines, offer a way to improve our knowledge of the disk geometry and/or composition. These results validate an earlier study by Pinte et al. 2008 and show that the dust inner radii of T Tauri disks now appear to be in better agreement with the expected position of the dust sublimation radius, contrary to previous claims.
TW Hydrae: multi-wavelength interferometry of a transition disk
Authors: Menu J. , van Boekel R. , Henning T. , Benisty M. , Chandler C. J. , Linz H. , Waelkens C. , Andrews S. M. , Calvet N. , Carpenter J. M. , Corder S. A. , Deller A. T. , Dullemond C. P. , Greaves J. S. , Harris R. J. , Isella A. , Kwon W. , Lazio J. , Mundy L. G. , Perez L. M. , Ricci L. , Sargent A. I. , Storm S. , Testi L. , Wilner D. J. 
Published: January 2014

AbstractFor over a decade, the structure of the inner “hole” in the transition disk around TW Hydrae has been a subject of debate. To probe the innermost regions of the protoplanetary disk, observations at the highest possible spatial resolution are required. We present new interferometric data of TW Hya from near-infrared to millimeter wavelengths. We confront existing models of the disk structure with the complete data set and develop a new, detailed radiative-transfer model. This model is characterized by: 1) a spatial separation of the largest grains from the small disk grains; and 2) a smooth inner rim structure, rather than a sharp disk edge.
Probing planet nurseries with rare isotopologues of CO
Authors: Dodson-Robinson Sarah E. , Yu Mo , Willacy Karen 
Published: January 2014

AbstractThe properties of planet-forming midplanes of protostellar disks remain largely unprobed by observations due to the high optical depths of common molecular lines. However, rotational emission lines from rare isotopologues may have optical depth near unity in the vertical direction, so that the lines are strong enough to be detected, yet remain transparent enough to trace the disk midplane. We have computed chemical models of protostellar disks including different C and O isotopes and detailed photochemical reactions. The CO condensation front is in the giant planet-forming region, within 20 AU of the star. We show that the optical depths of low-order rotational lines of C17O are around unity, which suggests that it may be possible to see into the disk midplane using C17O. In lower-mass disks, the slightly more abundant C18O is a possible midplane probe. ALMA observations would provide estimates of the disk midplane temperature if CO ice line were spatially resolved. With our computed C17O/H2 abundance ratio, we would also be able to measure disk surface densities from the fluxes of low-order C17O transitions.
Can a planet explain different cavity sizes for small & large dust grains in transition disks?
Authors: Garufi Antonio , Avenhaus Henning , Quanz Sascha P. 
Published: January 2014

AbstractDissimilarities in the spatial distribution of small (μm–size) and large (mm–size) dust grains at the cavity edge of transition disks have been recently pointed out and are now under debate. We obtained VLT/NACO near-IR polarimetric observations of SAO 206462 (HD 135344B). The disk around the star shows very complex structures, such as dips and spirals. We also find an inner cavity much smaller than what is inferred from sub-mm images. The interaction between disk and orbiting companion(s) may explain this discrepancy.
First images from the PIONIER/VLTI optical interferometry imaging survey of Herbig Ae/Be stars
Authors: Kluska J. , Malbet F. , Berger J.-P. , Benisty M. , Lazareff B. , Le Bouquin J.-B. , Baron F. , Dominik C. , Isella A. , Juhasz A. , Kraus S. , Lachaume R. , Ménard F. , Millan-Gabet R. , Monnier J.D. , Pinte C. , Thi W.-F. , Thiebaut E. , Zins G. 
Published: January 2014

AbstractThe close environment of Herbig stars starts to be revealed step by step and it appears to be quite complex. Many physical phenomena interplay: the dust sublimation causing a puffed-up inner rim, a dusty halo, a dusty wind or an inner gaseous component. To investigate more deeply these regions, getting images at the first Astronomical Unit scale is necessary. This has become possible with near infrared instruments on the VLTI. We have developed a new imaging method adapted to young stellar objects where we process separately the stellar component from the rest of the image to reveal the environment by using the spectral differences between these two components. We present the result of this method on the first imaging survey of Herbig stars carried out by PIONIER on the VLTI.
The Story of Planets: Anchoring Numerics in Reality
Authors: Leinhardt Zoë M. 
Published: January 2014

AbstractBuilding a complete coherent model of planet formation has proven difficult. There are gaps in the observational record, difficult physical processes that we have yet to fully understand, such as planetesimal formation, and an extensive list of observationally determined constraints that the model must fulfil. For example, the diversity of extrasolar planets detected to date is staggering – from single hot-Jupiters to multiple planet systems with several tightly packed super-Earths. In addition, the characteristics of the host stars are broad from single solar-mass stars to tight binaries and low mass, low metalicity stars. Even more surprising, perhaps, is the frequency of detection and thus, the implied efficiency of the planet formation process. Any theoretical model must not just be able to explain how planets form but must also explain the frequency and diversity of planetary systems. So why is planet formation so prolific? What parameters determine the type of planetary system that will result? How important are the initial parameters of the protoplanetary disk, such as composition, versus stochastic effects, such as gravitational scattering events, that occur during the evolution of the planetary system?Current observations of extrasolar planets provide snapshots in time of the earliest and latest stages of planet formation but do not show the evolution between the two. It is at this point that we must rely on numerical models to evolve proto-planetary disks into planets. But how can we validate the results of our numerical simulations if the middle stages of planet formation are effectively invisible? Collisions are a core component of planet formation. Planetesimals, the building blocks of planets, collide with one another as they grow and evolve into planets or planetary cores and are viscously stirred by larger protoplanets and fully-formed planets. The range of impact parameters encountered during growth from planetesimals to planets span multiple collision outcome regimes: cratering, merging, disruption, and hit-and-run events. Most of these collisions produce significant debris and dust. If we have a good understanding of the production of collisional debris we can use it as an indirect tracer of on-going planetary evolution even if the planets themselves are not directly detectable.In this paper I will show how numerical simulations of planet formation including realistic collision modelling can be used to predict, and be constrained by, observations.
The different faces of transitional discs
Authors: de Juan Ovelar M. , Min M. , Dominik C. , Thalmann C. , Pinilla P. , Benisty M. , Birnstiel T. 
Published: January 2014

AbstractRecent imaging observations of transitional discs have revealed discrepancies between the structure observed at different wavelengths. In some targets, the gap measured using sub-mm observations disappears when observed using near infrared polarimetry, suggesting that the empty region is actually filled with small particles of dust (Dong et al., 2012). Assuming the gapped structure observed in transitional discs is caused by the presence of a planet, we try to explain such discrepancies simulating observations of physical models of disc/planet systems with VLT/SPHERE-ZIMPOL, Subaru/HiCIAO, VLT/VISIR and ALMA.
Visible Light Adaptive Optics Imaging of the Orion 218-354 Silhouette Disk
Authors: Follette Katherine B. , Close Laird M. , Males Jared R. , Kopon Derek , Wu Ya-Lin , Morzinski Katie M. , Hinz Philip , Rodigas Timothy J. , Puglisi Alfio , Esposito Simone , Riccardi Armando , Pinna Enrico , Xompero Marco , Briguglio Runa 
Published: January 2014

AbstractWe present the first ground-based adaptive optics images of a silhouette disk. This disk, Orion 218-354, is seen in silhouette against the bright nebular background of Orion, and was resolved using the new Magellan Adaptive Secondary AO system and its VisAO camera in Simultaneous Differential Imaging (SDI) mode. PSF subtraction of Orion 218-354 reveals a disk ~1″ (400 AU) in radius, with the degree of absorption increasing steadily towards the center of the disk. By virtue of the central star being unsaturated, these data probe inward to a much smaller radius than previous HST images. Our data present a different picture than previous observers had hypothesized, namely that the disk is likely optically thin at Hα at least as far inward as ~20AU. In addition to being among the first high-resolution AO images taken in the optical on a large telescope, these data reveal the power of SDI imaging to illuminate disk structure, and speak to a bright future for visible AO imaging. Analysis of the results described briefly here can be found in full detail in Follette et al. (2013).
A gas-rich disk around DX Cha
Authors: Hales A. S. , De Gregorio-Monsalvo I. , Montesinos B. , Casassus S. , Dent W. R. F. , Eiroa C. , Hughes A. M. , Garay G. , Mardones D. , Ménard F. , Palau A. , Pérez S. , Phillips N. , Torrelles J. M. , Wilner D. 
Published: January 2014

AbstractDX Cha (HD 104237) is a southern, optically bright Herbig Ae star with an infrared excess, that is part of a small stellar group younger than 5 Myr. We used the APEX and ASTE submillimeter telescopes in Chile to search for continuum and gas emission around this system. Using LABOCA on APEX we detect strong continuum emission around HD104237-A and system component HD104237-E. Our ASTE spectrum detects a double-peaked 12CO(3-2) line profile towards the system, typical of a rotating disk. The new data are used as constraints with MCFOST to produce a disk model that fits the entire SED as well as the observed CO line profile.
LIPAD Simulations of Giant Planet Core Formation
Authors: Ngo Henry , Duncan Martin J. , Levison Harold F. 
Published: January 2014

AbstractWe present some preliminary results from our investigation of giant planetary core formation using numerical simulations with the Lagrangian Integrator for Planetary Accretion and Dynamics (LIPAD) by Levison et al. (2012). LIPAD couples dynamics with collisional evolution, including fragmentation. We start with a cold planetesimal disk using particles of a few kilometres in size. Our simulations show growth from kilometre-sized planetesimals to several Earth-mass sized embryos (tens of thousands of kilometers) can occur. However, these embryos may not be large enough to start runaway gas accretion necessary to build the envelopes of gas giant planets.
Disk Inhomogeneities and the Origins of Planetary System Architectures and Observational Properties
Authors: Hasegawa Yasuhiro , Pudritz Ralph E. 
Published: January 2014

AbstractRecent high-resolution observations show that protoplanetary disks have various kinds of structural properties or inhomogeneities. These are the consequence of a mixture of a number of physical and chemical processes taking place in the disks. Here, we discuss the results of our comprehensive investigations on how disk inhomogeneities affect planetary migration. We demonstrate that disk inhomogeneities give rise to planet traps - specific sites in protoplanetary disks at which rapid type I migration is halted. We show that up to three types of traps (heat transitions, ice lines and dead zones) can exist in a single disk, and that they move differently as the disk accretion rate decreases with time. We also demonstrate that the position of planet traps strongly depends on stellar masses and disk accretion rates. This indicates that host stars establish preferred (initial) scales of their planetary systems. Finally, we discuss the possible observational signatures of disk inhomogeneities.
Asymmetric dust distribution in an eccentric protoplanetary disk as a signpost of a gas giant planet
Authors: Gu Pin-Gao , Hsieh He-Feng , Yeh Hsi-Wei 
Published: January 2014

AbstractThe presence of a cavity in a protoplanetary disk revealed by dust continuum emissions is sometimes postulated as a signpost of an embedded gas giant planet. More peculiarly, dust emissions exterior to the cavity are often observed to be asymmetric. We explore the possibility of the asymmetry as a result of the asymmetric distribution of dust in an eccentric protoplanetary disk under the secular gravitational perturbation of an embedded massive gas giant planet. We find that the surface density of the dust well coupled to the disk gas is enhanced around the apocenter of the disk. In addition, the azimuthal distributions of particles of various sizes can deviate significantly due to different coupling to the gas. Overall, the asymmetric structure exhibits a phase correlation between the gas velocity field and dust density distribution. A Doppler map for an eccentric disk is also presented based on Cycle 1 ALMA observations. Our study potentially provides a reality check as to whether an asymmetric disk gap detected at sub-mm and cm wavelengths is a signpost of a massive gas giant planet.
The TBOSS (Taurus Boundary of Stellar/Substellar) Survey of Disk Properties
Authors: Patience J. , Bulger J. , Ward-Duong K. , Bouy H. , Pinte C. , Ménard F. , Monin J.-L. , Koda J. , Dowell C. D. 
Published: January 2014

AbstractWith the combination of Herschel PACS (far-IR), submillimeter (submm) and millimeter (mm) ground-based observations, we are leading an investigation of all members with spectral types M4 and onwards in the Taurus star-forming region. This complete census spans the stellar to substellar boundary (M6.25), and the wavelength range covers the transition from optically thick to optically thin emission. From our Hershel PACS observations of ~135 sources, we obtain a detection rate of ~40% at 70 μm and a detection rate of ~20% at 160 μm, and provide the first far-IR measurements for the majority of these members. With our complementary submm and mm observations, best fit SED models from the radiative transfer code MCFOST will be used to infer disk properties such as scale height, mass, outer radius and maximum dust grain size. These comprehensive population statistics of disks are critical for testing star/brown dwarf and planet formation models around these later type members of Taurus.
The Debiased Kuiper Belt: Our Solar System as a Debris Disk
Authors: Lawler Samantha M. ,   the CFEPS Team
Published: January 2014

AbstractThe dust measured in debris disks traces the position of planetesimal belts. In our Solar System, we are also able to measure the largest planetesimals directly and can extrapolate down to make an estimate of the dust. The zodiacal dust from the asteroid belt is better constrained than the only rudimentary measurements of Kuiper belt dust. Dust models will thus be based on the current orbital distribution of the larger bodies which provide the collisional source. The orbital distribution of many Kuiper belt objects is strongly affected by dynamical interactions with Neptune, and the structure cannot be understood without taking this into account. We present the debiased Kuiper belt as measured by the Canada-France Ecliptic Plane Survey (CFEPS). This model includes the absolute populations for objects with diameters >100 km, measured orbital distributions, and size distributions of the components of the Kuiper belt: the classical belt (hot, stirred, and kernel components), the scattering disk, the detached objects, and the resonant objects (1:1, 5:4, 4:3, 3:2 including Kozai subcomponent, 5:3, 7:4, 2:1, 7:3, 5:2, 3:1, and 5:1). Because a large fraction of known debris disks are consistent with dust at Kuiper belt distances from the host stars, the CFEPS Kuiper belt model provides an excellent starting point for a debris disk model, as the dynamical interactions with planets interior to the disk are well-understood and can be precisely modelled using orbital integrations.