bluuebunny/crossref_metadata_2025 huggingface dataset:
State Ceremony and Music in Meiji-era Japan
Authors: Tsukahara Yasuko
Published: January 2014

The music culture of Japan following the Meiji Restoration of 1868 is characterized by the coexistence and interdependent development of three types of music: (1) traditional music passed down from the Edo period (1603–1867) as exemplified by gagaku (court music); (2) the Western music that entered the country and became established after it was opened to the outside world; and (3) modern songs that were the first to be created in East Asia, such as shōka and gunka (school and military songs). These three types of music each played the role required of them by the Meiji state, and they became indispensable elements of the music culture of modern Japan. Traditional music is an irreplaceable fund of original musical expression intrinsic to Japan, Western music offers a common language facilitating musical contact in international society, especially with countries of the West, and modern songs are an essential tool for unifying the Japanese people through the act of ‘singing together in Japanese’.

This article examines the way in which the coexistence of these three types of music began, from the perspective of the musical expression of national identity in the state ceremonies of the Meiji era, namely imperial rites, military ceremonies and school ceremonies. Gagaku was reorganized and strengthened in the 1870s as the music of Japan's imperial rites, and it was given priority both within Japan and overseas, as the most intrinsic of Japan's genres of traditional music. The gagaku scales, defined clearly only from 1878 onwards, were used to amalgamate the musical language of Japan's state ceremonies by their use in ceremonial pieces for military and school ceremonies. This article clarifies the special role played by gagaku in post-Restoration nineteenth-century Japan.
A Lost Opportunity for Tradition: The Violin in Early Twentieth-Century Japanese Traditional Music
Authors: Kajino Ena
Published: January 2014

Less than a century after the introduction of the violin to Japan, in the late nineteenth century, Japan offers the highest level of training on the instrument and has produced many internationally successful violinists. Although one can hardly imagine it from the current role of the violin in modern Japan, in the early twentieth century the instrument played a significant role, not in the development there of Western classical music, but in the survival of the indigenous Japanese music that we call today ‘traditional Japanese music’.

With the flood of Western culture into Japan after the Meiji Restoration, of 1868, the Japanese government reconsidered whether their native music was worthy of Japan as a civilized country. In fact, except for court music, native Japanese music was held in low esteem by society and the government alike. The music of theshamisenwas particularly problematic, due to the vulgar texts ofshamisensongs and the low class status ofshamisenconsumers.Shakuhachihad until recently been restricted to Fuke monks, and was still establishing a new role in the musical culture. Thus, the whole world of ‘traditional Japanese music’ was entering a new age.

It was during this period that many Japanese became acquainted with the violin, by playing it in ensemble withkoto, shamisenandshakuhachi.Young Japanese professional musicians began to learn the violin. The principles of Western music they learned in this way gradually made their way into Japanese music. At one time, the ‘traditional Japanese music’ ensemble of violin with Japanese instruments seemed to have become firmly rooted in Japan as ‘home music’; but this has not turned out to be the case. As Japanese violinists have become increasingly dedicated to Western classical music, traditional Japanese music has once again become the exclusive use of native instruments.
Characterisation of the Galactic thick disk
Authors: Bensby Thomas
Published: January 2014

Thick disks appear to be common in external large spiral galaxies and our own Milky Way also hosts one. The existence of a thick disk is possibly directly linked to the formation history of the host galaxy and if its properties is known it can constrain models of galaxy formation and help us to better understand galaxy formation and evolution. This brief review attempts to highlight some of the characteristics of the Galactic thick disk and how it relates to other stellar populations such as the thin disk and the Galactic bulge. Focus has been put on results from high-resolution spectroscopic data obtained during the last 10 to 15 years.
Moving Groups in the Galactic Disc
Authors: Ramya P. , Reddy B. E.
Published: January 2014

We present results of chemical abundance study of a few representative stellar streams of Galactic thick and thin discs. Arcturus stream, which was proposed to have an extragalactic origin, and a recently detected stream called AF06 were studied. Results show a range of metallicity, age and abundance pattern that are consistent with those of Galactic thick disc component. We found similar results for AF06. The abundance and age results unambiguously rule out the possibility that the member stars are vestiges of open clusters. Abundance results of a sample of stars of Sirius and Hercules streams combined with the kinematics show that both the streams belong to the thin disc component. Also, results rule out these are remnants of open clusters. It is likely these streams formed insitu due to perturbations caused by non-axisymmetric components such as bar or spirals.
A comprehensive tool for the statistical comparison of Large Surveys to Models of the Galaxy
Authors: Ritter Andreas
Published: January 2014

The advent of large spectroscopic surveys of the Galaxy offers the possibility to compare Galactic models to actual measurements for the first time. I have developed a tool for the comprehensive comparison of any large data set to the predictions made by models of the Galaxy using sophisticated statistical methods, and to visualise the results for any given direction. This enables us to point out systematic differences between the model and the measurements, as well as to identify new (sub-)structures in the Galaxy. These results can then be used to improve the models, which in turn will allow us to find even more substructures like stellar streams, moving groups, or clusters. In this paper I show the potential of this tool by applying it to the RAdial Velocity Experiment (RAVE, Steinmetz 2003) and the Besançon model of the Galaxy Robin et al. 2003.
Dynamical Structures in the Galactic Disk
Authors: Quillen Alice C.
Published: January 2014

Resonances with spiral density waves or the Galactic bar can cause structure in local velocity distributions (also known as phase space). Because resonances are narrow, it is possible to place tight constraints on a pattern speed or the shape of the underlying gravitational potential.

Interference between multiple spiral patterns can cause localized bursts of star formation and discontinuities or kinks in the spiral arm morphology. Numerical simulations suggest that boundaries between different dominant patterns in the disk can manifest in local velocity distributions as gaps that are associated with specific orbital periods or angular momentum values. Recent studies have detected age gradients that may be associated with the appearance of spiral features such as armlets and spurs.

When patterns grow or vary in speed, resonances can be swept through the disk causing changes in the velocity distributions. Evidence of resonance capture or resonance crossing can be used to place constraints on the past history of patterns in the disk. The X-shaped Galactic bulge may have been caused by stars captured into vertical resonance with the Bar.

Disturbances in the Galactic disk, such as from a past merger, can cause an uneven distribution of disk stars in action angles. Subsequently the stellar distribution becomes more tightly wound in phase space. Phase wrapping can cause a series of shell like features in either real space or in a local velocity distribution. The spacing between features is dependent on the time since the disturbance.
Constraining dynamical models with observational data
Authors: Bovy Jo
Published: January 2014

The spatial distribution and kinematics of stars in the Milky Way are linked through the gravitational potential. Observations of the positions and velocities of stars can therefore be used to measure the mass distribution of the Milky Way. I review steady-state dynamical modeling approaches and illustrate their use in constraining the local matter distribution and the circular velocity curve from the kinematics of stellar tracers. In a few years, Gaia will increase the number of precise positions and velocities by multiple orders of magnitude. I describe some of the dynamical analyses that will be possible with the Gaia data and discuss some promising avenues for the optimal analysis of dynamical data.
Dynamical Modeling of the Milky Way Bugle
Authors: Shen Juntai
Published: January 2014

Bulges are commonly believed to form in the dynamical violence of galaxy collisions and mergers. We model the stellar kinematics of the Bulge Radial Velocity Assay (BRAVA) and find no sign that the Milky Way contains a classical bulge formed by scrambling pre-existing disks of stars in major mergers. Rather, the bulge appears to be a bar seen somewhat end-on, as hinted from its asymmetric boxy shape. We construct a simple but realistic N-body model of the Galaxy that self-consistently develops a bar. The bar immediately buckles and thickens in the vertical direction. As seen from the Sun, the result resembles the boxy bulge of our Galaxy. We use the new kinematic constraints to show that the classical bulge contribution cannot be very significant. The model fits the BRAVA stellar kinematic data covering the whole bulge strikingly well with no need for a merger-made classical bulge. Our model contains an intriguing vertical X-shaped structure that resembles the similar structure reported recently in the Galactic bulge. The existence of the vertical X-shaped structure also suggests that the formation of the Milky Way bulge is shaped mainly by internal disk dynamical instabilities.
Unveiling the Galaxy with Gaia
Authors: Vallenari Antonella
Published: January 2014

The Gaia Mission due for launch this year will revolutionise our understanding of the formation and evolution of the Milky Way and of the astrophysics in general. This paper reviews the current status of the Mission, and the expected accuracies as derived from instrument performance assessment.
The RAVE harvest: from the relation between abundances and kinematic of the Milky Way stars to tools for the abundance analysis of the spectra
Authors: Boeche Corrado ,   the RAVE collaboration
Published: January 2014

RAVE is a spectroscopic survey of the Milky Way which collected more than 500,000 stellar spectra of nearby stars in the Galaxy. The RAVE consortium analysed these spectra to obtain radial velocities, stellar parameters and chemical abundances. These data, together with spatial and kinematic information like positions, proper motions, and distance estimations, make the RAVE database a rich source for galactic archaeology. I present recent investigations on the chemo-kinematic relations and chemical gradients in the Milky Way disk using RAVE data and compare our results with the Besançon models. I also present the code SPACE, an evolution of the RAVE chemical pipeline, which integrates the measurements of stellar parameters and chemical abundances in one single process.
Chromospherically Active Stars in the RAVE Survey
Authors: Žerjal M. , Zwitter T. , Matijevič G. , Strassmeier K. G. ,   RAVE Collaboration
Published: January 2014

We present a qualitative characterization of activity levels of a large database of ~44,000 candidate RAVE stars (unbiased, magnitude limited medium resolution survey) that show chromospheric emission in the Ca II infrared triplet and this vastly enlarges previously known samples. Our main motivation to study these stars is the anti-correlation of chromospheric activity and stellar ages that could be calibrated using stellar clusters with known ages. Locally linear embedding used for a morphological classification of spectra revealed 53,347 cases with a suggested emission component in the calcium lines. We analyzed a subsample of ~44,000 stars with S/N>20 using a spectral subtraction technique where observed reference spectra of inactive stars were used as templates instead of synthetic ones. Both the equivalent width of the excess emission for each calcium line and their sum is derived for all candidate active stars with no respect to the origin of their emission flux. ~17,800 spectra show a detectable chromospheric flux with at least 2 σ confidence level. The overall distribution of activity levels shows a bimodal shape, with the first peak coinciding with inactive stars and the second with the pre-main-sequence cases.
Properties of abundance gradient along the Galactic disk and the role of LAMOST
Authors: Hou J.L. , Chen L. , Yu J.C. , Sellwood J. , Pryor C.
Published: January 2014

In this paper, we present our recent work on the evolution of abundance gradients along the Milky Way disk based on the Geneva Copenhagen Survey (GCS) and Radial Velocity Experiment (RAVE) data. We will also discuss the role of the LAMOST Milky Way disk survey in clarifying the properties of metallicity breaks observed through open clusters and young tracers along the Milky Way disk. It is believed that the Galactic disk forms inside-out, in which the stellar population at increasing radii is younger and more metal poor. This picture is consistent with most Galactic Chemical Evolution (GCE) models which also predict a tight correlation between the metallicity and age of stars at a given radius. However, it is only a result of “steady state" and no dynamical evolution effects were taken into account. We have selected two stellar samples from GCS and RAVE, each sample contains about 10,000 local thin-disk, main-sequence stars. We use the guiding radius which is determined by the conservation of z-direction angular momentum, to eliminate the blurring effects. And also use the effective temperature of the main sequence stars as a proxy of stellar age. It is shown that the metallicity gradient flattens as the age increases. This is not consistent with our previous GCE prediction, but can be explained by radial mixing effects. In order to further demonstrate the abundance breaks observed in the Galactic disk we have proposed, and have been carrying out, an open cluster survey project based on LAMOST. We plan to observe at least 400 open clusters in the northern Galactic sky. From the observations, we will get uniform parameters for those clusters with radial velocity and metallicities. We anticipate that this uniform open cluster sample could clarify the observed abundance break around the Milky Way disk corotation radius and also give a more robust result concerning the evolution of the abundance gradient.
Strömgren-Crawford uvbyβ all sky survey - towards understanding of the Galaxy
Authors: Wang Wei , Zhao Gang , Chen Yuqin , Liu Yujuan
Published: January 2014

The Strömgren-Crawford (SC) intermediate-band photometric system is a very powerful and efficient one for the detailed study of stars, and therefore the Milky Way and local universe. However, due to the narrow bandwidth, low efficiency of detectors and serious atmospheric extinction in u band, and high photometric accuracy required, there was only one all sky survey in this system finished a decade ago, which is restricted to stars brighter than 8.3 mag in y (equal to V) in the solar neighborhood. In this context, it is the right time to carry out an all sky survey to a completeness depth of ~19 mag, equivalent to a volume-completed distance 4 kpc for solar-type stars. For stars brighter than 15 mag in V, the expected photometric accuracies are ~0.01mag. With these stars, high precision 3D extinction map can be obtained thanks to the β index. Stellar atmospheric parameters can be determined with accuracies comparable to those from high-resolution spectroscopy. Fundamental parameters like stellar luminosities and distances can be reliably estimated as well. We propose to use the Nanshan 1m telescope to start the survey in early 2014 in the Northern sky. There are several 1-m class telescopes in Chile which can be used to perform the Southern sky survey. This entire survey, when finished, will greatly improve our knowledge on stars and the Galaxy, and will provide us the first 6D map of the Milky Way together with the LAMOST survey and the Gaia mission.
Automated stellar abundance analysis
Authors: Recio-Blanco Alejandra
Published: January 2014

The advent of Milky Way high-resolution spectroscopic surveys has brought our attention to the importance of precise chemical abundance measurements to disentangle the stellar population puzzle of the Galaxy. Moreover, automated stellar parameters are the bedrock of Galactic spectroscopic surveys science. They allow a rapid and homogeneous processing of extensive data sets, necessary for an efficient scientific return. In this review, I discuss the different parametrization techniques, focusing on the automated determination of individual element abundances. Each of them has its optimal application conditions that mainly depend on the computation time constraints, the spectral resolution, the wavelength domain, the data signal-to-noise ratio and parameter degeneracy problems. The main algorithms in the literature are also reviewed.
Constraints on the Galactic bar with RAVE
Authors: Antoja T. , Helmi A. ,   the RAVE collaboration
Published: January 2014

We derive the pattern speed of the Galactic bar from the analysis of the kinematics of the Hercules stream at different Galactocentric radii with RAVE, assuming that Hercules is caused by the bar. We find a well constrained pattern speed of Ωb=1.98+0.04−0.08 Ωo, where Ω0 is the local circular frequency.
A systematic study of NLTE abundances of nearby stars
Authors: Chen Y. Q. , Zhao G. , Mashonkina L. , Shi J. R. , Zhang H. W. , Tan K. F.
Published: January 2014

Approximately 80 stars from the thin disk, the thick disk and the halo of the Galaxy, in the range of −3.0 < [Fe/H] < +0.5, surface gravity of 3.0 < logg < 4.7 and temperature of 4500 K < Teff < 6500 K, have been observed with the Shane/Hamilton and CFHT/Espadons spectrographs in order to carry out a systematic NLTE study of nearby stars in a consistent way. We will determine reliably stellar parameters and determine precise elemental abundances via a comprehensive NLTE analysis of the spectral lines of Li, Na, Mg, Al, Si, K, Ca, Sc, Mn, Fe, Sr, Zr, Ba, Nd, and Eu elements. Finally, we aim to investigate the chemical evolution of the Galaxy through different stellar populations based on the NLTE abundances for total 15 elements.
The Mixed Origin of the Galactic Thick Disk
Authors: Cui W. Y. , Liu C. , de Laverny P. , Recio-Blanco A. , Van de Ven G.
Published: January 2014

We found that the thick disk stars of the Galaxy should form from gas-rich mergers and minor merger or radial migration.
On Atomic Diffusion and the Cosmological Lithium Abundance
Authors: Gruyters Pieter , Korn Andreas J. , Barklem Paul S.
Published: January 2014

When it comes to lithium in late-type stars, atomic diffusion (AD) refers to the slow gravitational settling below the convective zone. Richard, Michaud & Richter, J. (2005) computed the influence of diffusion on the lithium abundance with different additional mixing (AddMix) parameters, after 13.5 Gyr with an initial Li abundance compatible with BBN. Without AddMix the abundance of lithium would decrease when the temperature of the star increases. This is depicted by the dashed green line in the left panel of Fig. 1 and is in contradiction with the existence of a lithium plateau. But with a model including ad-hoc AddMix, where the AddMix diffusion coefficient is given by DT and is connected to DHe(AD) at a reference temperature of log T0=6.25, it is possible to reproduce the plateau as seen in the figure (solid green line). AD with AddMix has so far been shown to be at work in two globular clusters (GC) with different metallicities. Korn et al. (2007) showed the effects in NGC 6397 at [Fe/H] = −2.1. More recently Gruyters et al. (2013) have shown smaller effects, but similar in nature, in NGC 6752 at [Fe/H] = −1.6. The Li abundance for both clusters can be brought in to agreement with predictions from the cosmic microwave background radiation and Big Bang nucleosynthesis (CMB+BBN) by using stellar structure models including AD and AddMix, although with different efficiencies of AddMix. It seems there is an evolution of AddMix with metallicity which renders AD less efficient. As AddMix acts only in the outer regions, helium settling in the core is not affected, and so the overall evolution (e.g. Teff-age relation) will be similar regardless of this parameter.
3D Galactic extinction modelling
Authors: Hanson Richard J. , Bailer-Jones Coryn A. L.
Published: January 2014

Using multi-band photometry we train a forward model to emulate the colour-change due to temperature and extinction for stars. We simultaneously solve for the astrophysical parameters (APs) extinction A0, temperature Teff and distance modulus μr in a Bayesian framework for individual stars. We introduce an HRD prior to account for previous knowledge about the distribution of stars in the temperature- absolute magnitude plane (see also Bailer-Jones 2011). This allows us to infer distance information. We obtain the full three dimensional PDFs of all the stars in a field, allowing us to determine extinction-distance profiles for a given line of sight.
Velocity distributions of surviving companion stars of type Ia supernovae in the Milky Way
Authors: Jia S. , Wang B. , Han Z.
Published: January 2014

The companion stars of type Ia supernovae (SNe Ia) would survive the explosions and show peculiar properties in the single-degenerate (SD) scenario. Whit different SD SN Ia channels, we obtained the velocity distributions of the surviving companion stars in the Milky Way. All properties presented may be verified by future observations.
Estimation of Galactic Model Parameters In High Latitude With SDSS and SCUSS
Authors: Jia Yunpeng , Du Cuihua
Published: January 2014

Using star counts method, we estimated the Galactic structure parameters in high latitude field (50° ≤ l ≤ 55°, −46° ≤ b ≤ −44°), 10 deg2 field with Sloan Digital Sky Survey (SDSS) and South Galactic Cap of U-band Sky Survey (SCUSS), to explore their possible variations with absolute magnitude. Here we just considered three components: double exponential thin disk and thick disk and a de Vaucouleurs halo. And these parameters were obtained by minimising χ2.
The abundance distribution of [α/Fe] in the Galactic disk stars
Authors: Li Ji , Fu Ruijuan
Published: January 2014

The abundance ratio [α/Fe] is a useful tracer to probe the history of star formation and the chemical evolution of the Galaxy. We present a statistical analysis of [α/Fe] in 953 dwarf stars to investigate the distributions of [α/Fe] in the the thin- and thick-disk stars.
The 3-D extinction law in the 2nd quadrant of the Galactic disk
Authors: Liu Chao , Fang Min , Wu Yue , Carrell Kenneth , Xue Xiangxiang , van de Ven Glenn
Published: January 2014

We estimate the 3D extinction law in the optical–NIR bands for a line of sight in the 2nd quadrant of the Galactic disk. Two dust lanes are identified at ~9 and ~10.25 kpc in both AV and RV, indicating that the size of the dust grains in the spiral arms is larger than that in the inter-arm regions.
The identification of K giant stars in LAMOST pilot survey
Authors: Liu Chao , Yang Fan , Deng Licai , Xu Yan , Cui Wenyuan , Xue Xiangxiang , Gao Shuang , Zhang Yueyang , Xin Yu
Published: January 2014

A support vector machine (SVM) method is applied to select K giant stars directly from the spectral features of LAMOST spectra. The performance of the algorithm is assessed using the MILES library. It shows that the completeness of the K giant stars is 87% with only about 6% dwarf contamination. This allows us to select 18,013 K giant stars at |b|>20° and 38,108 at |b|<20° from LAMOST pilot survey data.
Finding the lost siblings of the Sun
Authors: Liu Cheng , Feltzing Sofia , Ruchti Gregory
Published: January 2014

We have performed a spectral analysis on 18 stars solar sibling candidate. We found that only one one of the candidateshas solar metallicity and at the same time might have an age comparable to that of the Sun.
Near-infrared spectroscopy of Cepheids in the Galactic nuclear disk
Authors: Matsunaga Noriyuki , Fukue Kei , Kobayashi Naoto , Ikeda Yuji , Yamamoto Ryo , Kyu Shiori , Hamano Satoshi , Yasui Chikako , Tsujimoto Takuji , Aoki Wako , Nishiyama Shogo , Nagata Tetsuya , Genovali Katia , Inno Laura , Bono Giuseppe
Published: January 2014

We are carrying out near-infrared spectroscopy of Cepheids in the Galactic nuclear disk. The H-band spectra taken with SUBARU/IRCS indicate that their kinematics are consistent with the rotation of the nuclear disk.
Halo Kinematic Streams in the Era of Gaia
Authors: Fiorentin Paola Re , Curir Anna , Lattanzi Mario G. , Spagna Alessandro
Published: January 2014

We report on the discovery and characterization of a possibly new signature related to the formation of the Milky Way stellar local halo.
Helium double-detonation explosions for the progenitors of type Ia supernovae
Authors: Wang B. , Liu D. , Jia S. , Han Z.
Published: January 2014

Thermonuclear explosions from helium double-detonation sub-Chandrasekhar mass model have been considered as an alternative way for the production of type Ia supernovae (SNe Ia). In this work, we systematically studied the helium double-detonation model, in which a carbon–oxygen white dwarf (CO WD) accumulates a helium layer from a non-degenerate helium star.
Exploration of Galactic Structures beyond the Sun toward the anti-center of the Milky Way
Authors: Xu Yan , Newberg Heidi
Published: January 2014

We map the stellar distribution on Hess diagram in the Anti-Center roughly in the boxes 130<l<230, −30<b<−10 and 10<b<30. There are ‘extra components’ associated with the anti-center structures of figure 1 of Newberg et al. (2002). The turnoff point of the structure in the North sky is at 16m.5 and the turnoff point in the South is at 17m.5. In our work, these structures can be found in all of the longitude in our box that can't be explained by standard thin or thick disk models. The distance of the North structure is about 2 kpc (we call it the North near structure) and the galactic height is about 0.7 kpc, the distance of the South structure is about 4 – 6 kpc (we call it the South middle structure). The Vgsr distribution of stars selected along the North near structure has a kinematic distribution similar to that of thick disk stars. But the metallicities of these stars are quite similar to the metallicity distribution of thin disk stars. We try to explain these structures with wave structure of the Galactic plane.
Abundance analysis of barium stars
Authors: Yang Guochao , Liang Yanchun , Cui Wenyuan , Zhang Bo
Published: January 2014

We obtained the chemical abundances of more than 20 Barium (Ba) stars by analysing high resolution echelle spectra. They show obvious overabundances of neutron capture process elements, such as Y, Zr, Ba, La and Eu. Their abundance pattern can be explained by binary accretion through stellar wind, where the Ba stars have accreted the ejecta from the companion stars which were in AGB stages at that time and now evolve as white dwarfs.
Chromospheric activities of late-type stars based on Guoshoujing Telescope
Authors: Zhang L. Y. , Zhang G. Y. , Shi J. R. , Luo A. L. , Zhao J. K. , Zhao Y. H. , Wu H. , Zhou A. Y. , Pi Q. F. ,   LAMOST Collaboration
Published: January 2014

We present chromospheric activities of late-type stars based on stellar spectrum survey of LAMOST (also called GuoShouJing telescope) in 2010-2013. Using the equivalent widths of the Hα line (larger than 1 Å), we have found 6391 active stars from 99741 M stars.
Visible AO Observations at Halpha for Accreting Young Planets
Authors: Close L.M. , Follette K. , Males J.R. , Morzinski K. , Rodigas T.J. , Hinz P. , Wu Y-L. , Apai D. , Najita J. , Puglisi A. , Esposito S. , Riccardi A. , Bailey V. , Xompero M. , Briguglio R. , Weinberger A.
Published: January 2014

We utilized the new high-order (250-378 mode) Magellan Adaptive Optics system (MagAO) to obtain very high-resolution science in the visible with MagAO's VisAO CCD camera. In the good-median seeing conditions of Magellan (0.5–0.7″) we find MagAO delivers individual short exposure images as good as 19 mas optical resolution. Due to telescope vibrations, long exposure (60s) r' (0.63μm) images are slightly coarser at FWHM = 23-29 mas (Strehl ~ 28%) with bright (R < 9 mag) guide stars. These are the highest resolution filled-aperture images published to date. Images of the young (~ 1 Myr) Orion Trapezium θ1 Ori A, B, and C cluster members were obtained with VisAO. In particular, the 32 mas binary θ1 Ori C1C2 was easily resolved in non-interferometric images for the first time. Relative positions of the bright trapezium binary stars were measured with ~ 0.6–5 mas accuracy. In the second commissioning run we were able to correct 378 modes and achieved good contrasts (Strehl>20% on young transition disks at Hα). We discuss the contrasts achieved at Hα and the possibility of detecting low mass (~ 1–5 Mjup) planets (past 5AU) with our new SAPPHIRES survey with MagAO at Hα.
SCExAO: First Results and On-Sky Performance
Authors: Currie Thayne , Guyon Olivier , Martinache Frantz , Clergeon Christophe , McElwain Michael , Thalmann Christian , Jovanovic Nemanja , Singh Garima , Kudo Tomoyuki
Published: January 2014

We present new on-sky results for the Subaru Coronagraphic Extreme Adaptive Optics imager (SCExAO) verifying and quantifying the contrast gain enabled by key components: the closed-loop coronagraphic low-order wavefront sensor (CLOWFS) and focal plane wavefront control (“speckle nulling”). SCExAO will soon be coupled with a high-order, Pyramid wavefront sensor which will yield > 90% Strehl ratio and enable 106–107 contrast at small angular separations allowing us to image gas giant planets at solar system scales. Upcoming instruments like VAMPIRES, FIRST, and CHARIS will expand SCExAO's science capabilities.
Young Brown Dwarfs as Giant Exoplanet Analogs
Authors: Faherty Jacqueline K. , Cruz Kelle L. , Rice Emily L. , Riedel Adric
Published: January 2014

Young brown dwarfs and directly-imaged exoplanets have enticingly similar photometric and spectroscopic characteristics, indicating that their cool, low gravity atmospheres should be studied in concert. Similarities between the peculiar shaped H band, near and mid-IR photometry as well as location on color magnitude diagrams provide important clues about how to extract physical properties of planets from current brown dwarf observations. In this proceeding we discuss systems newly assigned to 10-150 Myr nearby moving groups, highlight the diversity of this uniform age-calibrated brown dwarf sample, and reflect on their implication for understanding current and future planetary data.
Estimation of Contaminants for Direct Imaging of Exoplanets: Constraint on the Stellar Distribution Model with both NIR and Deep Imaging Data
Authors: Konishi Mihoko , Shibai Hiroshi , Matsuo Taro , Yamamoto Kodai , Sudo Jun , Samland Matthias S. , Fukagawa Misato , Sumi Takahiro ,   SEEDS team
Published: January 2014

There are faint contaminants near primary stars in the direct imaging of exoplanets. Our goal is to estimate statistically the ratio of exoplanets in the detected batch of point sources by calculating the fraction of contamination. In this study, we compared the detected number of stars with the number of contaminants predicted by our model. We found that the observed number of faint stars were fewer than the predicted results towards the Pleiades and GOODS-South field when the parameters of the conventional stellar distribution models were employed. We thus estimated new model parameters in correspondence to the results of the observations.
High-fidelity photometry and astrometry of high-contrast imaged companions using LOCI processing.
Authors: Maire Jérôme , Gagné Jonathan , Lafrenière David , Graham James R. , Doyon René
Published: January 2014

Direct imaging and spectroscopy of exoplanets is a key element for understanding planet formation and migration. Such direct detections and characterizations remains technologically challenging, since a very high contrast ratio and small angular separation are involved, and futhermore speckle noise limits the high-contrast imaging performance. We further discuss a speckle subtraction and suppression technique that fully takes advantage of spectral and time-domain information on quasi-static speckles to measure the highest-fidelity photometry as well as accurate astrometry of detected companions.
Testing Optimized Principal Component Analysis on Coronagraphic Images of the Fomalhaut System
Authors: Meshkat Tiffany , Kenworthy Matthew , Quanz Sascha P. , Amara Adam
Published: January 2014

We present the results of a study to optimize the principal component analysis (PCA) algorithm for planet detection, a new algorithm complementing ADI and LOCI for increasing the contrast achievable next to a bright star. We apply PCA to our Fomalhaut VLT NACO Apodizing Phase Plate NB4.05 data.
The Gemini NICI Planet-Finding Campaign: The Frequency of Giant Planets around Young B and A Stars
Authors: Nielsen Eric L. , Liu Michael C. , Wahhaj Zahed , Biller Beth A. , Hayward Thomas L. ,   The Gemini NICI Planet-Finding Campaign Team
Published: January 2014

We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf and planetary companions as part of the Gemini NICI Planet-Finding Campaign. Our survey represents the largest, deepest survey for planets around high-mass stars (≈1.5–2.5 M⊙) conducted to date and includes the planet hosts β Pic and Fomalhaut. Despite detecting two new brown dwarfs, our observations did not detect new planets around our target stars, and we present upper limits on the fraction of high-mass stars that can host giant planets that are consistent with our null result.
Direct Imaging Of Long Period Radial Velocity Targets With NICI
Authors: Salter Graeme S. , Tinney Chris G. , Wittenmyer Robert A. , Jenkins James S. , Jones Hugh R.A. , O'Toole Simon J.
Published: January 2014

We are finally entering an era where radial velocity and direct imaging parameter spaces are starting to overlap. Radial velocity measurements provide us with a minimum mass for an orbiting companion (the mass as a function of the inclination of the system). By following up these long period radial velocity detections with direct imaging we can determine whether a trend seen is due to an orbiting planet at low inclination or an orbiting brown dwarf at high inclination. In the event of a non-detection we are still able to put a limit on the maximum mass of the orbiting body. The Anglo-Australian Planet Search is one of the longest baseline radial velocity planet searches in existence, amongst its targets are many that show long period trends in the data. Here we present our direct imaging survey of these objects with our results to date. ADI Observations have been made using NICI (Near Infrared Coronagraphic Imager) on Gemini South and analysed using an in house, LOCI-like, post processing.
A Direct Imaging Study to Search for and to Characterize Planetary Mass Companions
Authors: Ward-Duong K. , Patience J. , De Rosa R. J. , Rajan A. , Hinz P. , Skemer A. , Morzinski K. , Males J. , Close L. M. , McCarthy D. W. , Kulesa C.
Published: January 2014

We present preliminary results from two parallel programs to search for new substellar companions to nearby, young M-stars and to characterize the atmospheres of known planetary mass and temperature substellar companions. For the M-star survey, we are analyzing high angular resolution archival data on systems within 15pc, complementing a subset with well-determined young ages based on measurements of several age indicators. The results include stellar and substellar companion candidates, which we are currently pursuing with follow-up second epoch images. The characterization component of the project involves using LBT LMIRCam and MMT ARIES direct imaging and spectroscopy data to investigate the atmospheres of known young substellar companions with masses overlapping the planetary regime. These atmospheric studies will represent an analogous comparison to the atmospheres of young imaged planets, and provide a means to fundamentally test evolutionary models, enhancing our understanding of the overall substellar population.
HST Imaging of New Edge-on Circumstellar Disks in Nearby Star-forming Regions
Authors: Stapelfeldt K.R. , Duchêne G. , Perrin M. , Wolff S. , Krist J.E. , Padgett D.L. , Ménard F. , Pinte C.
Published: January 2014

Edge-on, optically thick circumstellar disks have been previously imaged at subarcsecond resolution around about a dozen nearby young stellar objects. In these systems the central star is occulted from direct view, bright star image artifacts are absent, and the disk reflected light is clearly seen. Comparison of Hubble Space Telescope (HST) edge-on disk images with scattered light models has allowed key disk structural parameters and dust grain properties to be determined. Edge-on disks have been systematically undercounted to date: while 10% of young stars should statistically be occulted by their disk, the observed frequency is much less. Thus there is a significant potential for discovering and imaging new examples. Spitzer Space Telescope legacy science programs have provided the first good spectral energy distribution (SED) measurements for the previously known edge-on disks. These can be used as templates to identify new candidates in far-infrared survey datasets.

We report on the results of our HST program to image twenty-one edge-on disk candidates mostly selected from their SEDs. Eleven are well-resolved with radii ranging from 30-400 AU, nine for the first time and six showing highly collimated jets. Outstanding individual sources include a large and symmetric new template object, a highly flattened disk not accreting onto its central star, and an asymmetric disk with a misaligned jet which likely traces tidal perturbations in a binary system. Follow-up work to obtain ancillary data and perform scattered light modeling of the most symmetric disks is now being pursued. The results of this program will guide a new round of searches for these rare but important snapshots of protoplanetary disk evolution.
Planet gaps in the dust layer of 3D proto-planetary disks: Observability with ALMA
Authors: Gonzalez J.-F. , Pinte C. , Maddison S. T. , Ménard F.
Published: January 2014

Among the numerous known extrasolar planets, only a handful have been imaged directly so far, at large orbital radii and in rather evolved systems. The Atacama Large Millimeter/submillimeter Array (ALMA) will have the capacity to observe these wide planetary systems at a younger age, thus bringing a better understanding of the planet formation process. Here we explore the ability of ALMA to detect the gaps carved by planets on wide orbits.
Probing protoplanetary disks with Aperture Masking
Authors: Lacour S. , Tuthill P. , Casassus S.
Published: January 2014

The interaction between planetary formation and protostellar disks is among the most critical remaining pieces in the puzzle of solar system assembly. Leading theoretical models are constructed around two distinct scenarios: gravitational instabilities and core accretion. The physics of each applies to quite different epochs of formation, and exhibits complex dependencies on parameters like disk density and viscosity. Untangling the effects such processes have on the final planetary statistics necessitates direct observation of exoplanets in their primordial state, prior to orbital migration. Furthermore, detailed study of the environment, such as the way the planets shape the protostellar disk by driving accretion streams across disk gaps, will also constrain formation models. Aperture masking interferometry has demonstrated a unique ability to probe the gaps within stellar disks. It has twin advantages of a higher dynamic range at the diffraction limit (λ/D) than differential imaging, while at the same time giving very extensive UV coverage compared to long baseline interferometry.
Problems and Prospects in Planetesimal Formation
Authors: Chiang Eugene , Murray-Clay Ruth , Shi Ji-Ming
Published: January 2014

On the long road from dust to planets there are planetesimals. We review and criticize proposed mechanisms for planetesimal formation, and point out topics for future work.
A Herschel View of Dust Evolution in Protoplanetary Disks
Authors: Espaillat Catherine
Published: January 2014

The details of how protoplanetary disks evolve from initially well-mixed distributions of gas and dust to systems composed mostly of rocky planets and gas giants like our own solar system is a fundamental question in astronomy. It is widely accepted that the first step in planet formation is dust grain growth and settling to the disk midplane. This dust evolution in disks can be studied in greater detail with far-infrared and submillimeter wavelength observations, which offer us unique access to the outer disk's deeper layers. Here we present Herschel far-infrared and submillimeter spectra of GM Aur taken with PACS and SPIRE. GM Aur is a transitional disk, whose inner disk hole is proposed to have been cleared by yet unseen planets. By utilizing Herschel data, we can potentially link the properties of dust evolution in the outer disk to dust clearing in the inner disk. In particular, preliminary SED modeling presented here suggests that GM Aur may have a lower gas-to-dust mass ratio than typically assumed for disks, which may be linked to disk clearing by planets. With further study, such Herschel data may provide insight for theoretical modeling of dust evolution and planet formation.
A First Look at the Disk Population in the Auriga-California Molecular Cloud
Authors: Broekhoven-Fiene Hannah , Matthews Brenda C. , Harvey Paul M. ,   members of the Spitzer Gould Belt Survey
Published: January 2014

The Auriga-California Molecular Cloud (AMC) is one of two nearby (within 500 pc) giant molecular clouds, the other being the Orion A Molecular Cloud (OMC). We aim to study the properties of circumstellar disks in the AMC to compare the planet formation potential and processes within the AMC to those for other clouds. A first look with measurements from Spitzer observations suggests that AMC disk properties, such as the distribution of disk luminosities and the evolution of the mid-IR excesses, are not vastly different from those in other regions. Follow-up observations in the submm, mm and cm can be used to measure disk masses and the degree of grain growth from spectral slopes to more completely characterize the disk population.
Ice Lines in Circumbinary Protoplanetary Disks
Authors: Clanton Christian D.
Published: January 2014

I find the location of the ice line in circumbinary disks heated by steady mass accretion and stellar irradiation, comparing the position with the minimum stable semimajor axis, interior to which planetary orbits are unstable. I show that there is a critical binary separation for which binaries with separations larger than this critical value have ice lines that lie interior to the boundary of stability. The critical separation for an equal-mass binary of 1 M⊙ stars is ≈ 1.04 AU, scaling weakly with mass accretion rate and Rosseland mean opacity of the disk. For a steady mass accretion rate of Ṁ ~ 10−8 M⊙ yr−1 and a Rosseland mean opacity of κR ~ 1 cm2 g−1, I show that ≳ 80% of all binary systems with component masses M☆ ≲ 2.0 M⊙ have ice lines interior to the boundary of stability. This suggests that rocky planets should not be common in these systems. Searching for planets around binaries with separations larger than the critical separation with Kepler or microlensing will provide a test of this prediction.
Dynamics of the inner edge of the dead zone in protoplanetary disks
Authors: Faure Julien , Fromang Sebastien , Latter Henrik
Published: January 2014

In protoplanetary disks, the inner boundary between an MRI active and inactive region has recently been suggested to be a promising site for planet formation. A set of numerical simulations has indeed shown that vortex formation mediated by the Rossby wave instability is a natural consequence of the disk dynamics at that location. However, such models have so far considered only the case of an isothermal equation of state, while the complex thermodynamics is at the heart of how this region works. Using the Godunov code Ramses, we have performed 3D global numerical simulations of protoplanetary disks that relax the isothermal hypothesis. We find that, at the interface, the disk thermodynamics and the turbulent dynamics are intimately entwined, because of the importance of turbulent dissipation and thermal ionisation.
The Early Era: How do protostellar discs form?
Authors: Joos Marc , Hennebelle Patrick , Ciardi Andrea , Fromang Sébastien
Published: January 2014

Discs are a key element in star and planet formation; however, magnetic fields can efficiently transport angular momentum away from the central region of the collapsing core during the dense core collapse, preventing disc formation. We perform numerical simulations of magnetically supercritical collapsing cores with a misalignment between the rotation axis and the magnetic field (Joos et al. 2012) and in a turbulent environment (Joos et al. 2013). The early formation of massive discs can take place at moderate magnetic intensities if the rotation axis is tilted or in a turbulent environment, because of misalignment and turbulent diffusion.
Gas signatures of Herbig Ae/Be disks probed with Herschel SPIRE spectroscopy
Authors: van der Wiel Matthijs H. D. , Naylor David A. , Aresu Giambattista , Olofsson Göran
Published: January 2014

Herbig Ae/Be objects, like their lower mass counterparts T Tauri stars, are seen to form a stable circumstellar disk which is initially gas-rich and could ultimately form a planetary system. We present Herschel SPIRE 460–1540 GHz spectra of five targets out of a sample of 13 young disk sources, showing line detections mainly due to warm CO gas.
Orbital Motion and Multi-Wavelength Monitoring of LkCa15 b
Authors: Ireland Michael J. , Kraus Adam L.
Published: January 2014

As part of a deep multi-year non-redundant aperture mask infrared imaging campaign observing transition disks, we present multi-epoch monitoring of the resolved emission seen within the disk gap of LkCa 15. Orbital motion of both the central source and extended lobes as presented in Kraus and Ireland (2012) is clearly detected at the level of ~4 degrees/year (deprojected), in both K and L'-bands. Based on these data as well as single-epoch H and M bands epochs, we present two models for the central source - thermal emission as a planetary accretion signature and scattering. The thermal emission model is preferred.
A VLT/X-Shooter study of accretion and photoevaporation in Transitional Disks
Authors: Manara C. F. , Testi L. , Natta A. , Ricci L. , Benisty M. , Rosotti G. , Ercolano B.
Published: January 2014

We present preliminary results of a detailed study of the accretion, stellar, and wind properties of transitional disks (TDs) carried out with the X-Shooter spectrograph. Combining new and archival spectra, we collected a sample of more than 20 TDs from different nearby star-forming regions. Our sample includes objects with both small (<5-15 AU) and large (>20–30 AU) known inner hole size from the literature (either from mm-observations or IR SED fitting). We check their stellar parameters (Teff, L*, AV, M*) and derive their accretion properties (Lacc, Ṁacc) in a self-consistent way, which makes use of the wide wavelength coverage of X-Shooter, and study their wind properties by mean of different forbidden emission lines analysis.