bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical and Electronic Properties of Pyrite Nanocrystal Thin Films: the Role of Ligands
Authors: Li Wei , Dittrich Thomas , Jäckel Frank , Feldmann Jochen
Published: January 2014

Pyrite nanocrystals are currently considered as a promising material for large scale photovoltaic applications due to their non‐toxicity and large abundance. While scalable synthetic routes for phase‐pure and shape controlled colloidal pyrite nanocrystals have been reported, their use in solar cells has been hampered by the detrimental effects of their surface defects. Here, we report a systematic study of optical and electronic properties of pyrite nanocrystal thin films employing a series of different ligands varying both the anchor and bridging group. The effect of the ligands on the optical and electronic properties is investigated by UV‐vis/NIR absorption spectroscopy, current voltage characteristic measurements and surface photovoltage spectroscopy. We find that the optical absorption is mainly determined by the anchor group. The absorption onset in the thin films shifts up to ∼100 meV to the red. This is attributed to changes in the dielectric environment induced by different anchors. The conductivity and photoconductivity, on the other hand, are determined by combined effects of anchor and bridging group, which modify the effective hopping barrier. Employing different ligands, the differential conductance varies over four orders of magnitude. The largest redshift and differential conductance are observed for ammonium sulfides and thiolated aromatic linkers. Pyridine and long chain amines, on the other hand, lead to smaller modifications. Our findings highlight the importance of surface functionalization and interparticle electronic coupling in the use of pyrite nanocrystals for photovoltaic devices.
Shaking table model test and FE analysis of a reinforced concrete mega‐frame structure with tuned mass dampers
Authors: Jiang Qing , Lu Xinzheng , Guan Hong , Ye Xianguo
Published: January 2014

To study the damage characteristics and to evaluate the overall seismic performance of reinforced concrete mega‐frame structures, a shaking table test of a 1/25 scaled model with a rooftop tuned mass damper (TMD) is performed. The maximum deformation and acceleration responses are measured. The dynamic behavior and the damping effect with and without TMD are compared. The results indicate that the mega‐frame structure has excellent seismic performance and the TMD device has a significant vibration reduction effect. A finite element (FE) model simulating the scaled model is also developed, and the numerical and experimental results are compared to provide a better understanding of the overall structural behavior in particular those related to the dynamic characteristics and damping effect. Upon verification of the FE model, other important structural behavior can also be predicted by the FE analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Microstructure and stress rupture properties of polycrystal and directionally solidified castings of nickel-based superalloys
Authors: Wu Bao-ping , Li Lin-han , Wu Jian-tao , Wang Zhen , Wang Yan-bin , Chen Xing-fu , Dong Jian-xin , Li Jun-tao
Published: January 2014

A new directionally solidified Ni-based superalloy DZ24, which is a modification of K24 alloy without rare and expensive elemental additions, such as Ta and Hf, was studied in this paper. The microstructure and stress rupture properties of conventionally cast and directionally solidified superalloys were comparatively analyzed. It is indicated that the microstructure of K24 alloy is composed of γ, γ′, γ/γ′ eutectics and MC carbides. Compared with the microstructure of K24 polycrystalline alloy, γ/γ′ eutectic completely dissolves into the γ matrix, the fine and regular γ′ phase reprecipitates, and MC carbides decompose to M6C/M23C6 carbides after heat treatment in DZ24 alloy. The rupture life of DZ24 alloy is two times longer than that of K24 alloy. The more homogeneous the size of γ′ precipitate, the longer the rupture life. The coarsening and rafting behaviors of γ′ precipitates are observed in DZ24 alloy after the stress-rupture test.
Association of dietary calcium, phosphorus, and magnesium intake with caries status among schoolchildren
Authors: Lin Han‐Shan , Lin Jia‐Rong , Hu Suh‐Woan , Kuo Hsiao‐Ching , Yang Yi‐Hsin
Published: January 2014

The aim of this study was to investigate the associations between caries experience and daily intake of calcium (Ca), phosphorus (P), magnesium (Mg), and Ca/P ratio. A total of 2248 schoolchildren were recruited based on a population‐based survey. Each participant received a dental examination and questionnaire interviews about the 24‐hour dietary recalls and food frequency. The daily intake of Ca, P, Mg, and Ca/P ratio were inversely associated with primary caries index, but only the Ca/P ratio remained significant after adjusting for potential confounders. According to the Taiwanese Dietary Reference Intakes, the Ca/P ratio was related to both caries in primary teeth (odds ratio = 0.52, p = 0.02) and in permanent teeth (odds ratio = 0.59, p = 0.02). The daily intakes of Ca/P ratio remained an important factor for caries after considering potential confounding factors.
Efficient detection of factor IX mutations by denaturing high‐performance liquid chromatography in Taiwanese hemophilia B patients, and the identification of two novel mutations
Authors: Lin Pei‐Chin , Su Yi‐Ning , Liao Yu‐Mei , Chang Tai‐Tsung , Tsai Shih‐Pien , Shu Hsiu‐Lan , Chiou Shyh‐Shin
Published: January 2014

Hemophilia B (HB) is an X‐linked recessive disorder characterized by mutations in the clotting factor IX (FIX) gene that result in FIX deficiency. Previous studies have shown a wide variation of FIX gene mutations in HB. Although the quality of life in HB has greatly improved mainly because of prophylactic replacement therapy with FIX concentrates, there exists a significant burden on affected families and the medical care system. Accurate detection of FIX gene mutations is critical for genetic counseling and disease prevention in HB. In this study, we used denaturing high‐performance liquid chromatography (DHPLC), which has proved to be a highly informative and practical means of detecting mutations, for the molecular diagnosis of our patients with HB. Ten Taiwanese families affected by HB were enrolled. We used the DHPLC technique followed by direct sequencing of suspected segments to detect FIX gene mutations. In all, 11 FIX gene mutations (8 point mutations, 2 small deletions/insertions, and 1 large deletion), including two novel mutations (exon6 c.687–695, del 9 mer and c.460–461, ins T) were found. According to the HB pedigrees, 25% and 75% of our patients were defined as familial and sporadic HB cases, respectively. We show that DHPLC is a highly sensitive and cost‐effective method for FIX gene analysis and can be used as a convenient system for disease prevention.
Telling Stories about Conflict: Symbolic Politics and the Ipperwash Land Transfer Agreement
Authors: Morden Michael
Published: January 2014

Abstract.Direct protest actions by Indigenous peoples in Canada have rarely yielded the specific gains that were targeted. In the aftermath of conflict, Canadian governments have typically proven to be intransigent. An exception to this general tendency is the Anishinabek occupation of Ipperwash Provincial Park, which began in 1995. In 2007, the government of Ontario agreed to return the parkland to the First Nation, making it an unusually successful instance of direct action. It is argued here that this outcome can best be explained by drawing on the “symbolic politics” theory of intergroup conflict. The Ipperwash inquiry, acting as a post-conflict truth commission, generated a micro-narrative shared by both groups, which altered the political incentive structure and enabled the outlier accommodative outcome.

Résumé.Les actions de protestation directe par les peuples autochtones du Canada ont rarement donné les résultats recherchés. Au lendemain d'un conflit, les gouvernements canadiens se sont généralement montrés intransigeants. L'occupation du Parc provincial d'Ipperwash par les Anishinabek, qui débuta en 1995, représente toutefois une exception à cette tendance générale. Le gouvernement ontarien a accepté, en 2007, de retourner les territoires du parc à cette première nation, ce qui en fait un des rares cas où l'action directe a porté fruit. L'article soutient que c'est en s'appuyant sur la théorie de la politique symbolique des conflits intergroupes qu'il est possible d'expliquer ce résultat. Agissant comme une commission de vérité et de réconciliation, la Commission d'enquête sur Ipperwash a généré un récit commun, partagé par les deux groupes. En changeant la structure d'incitatifs politiques, ce récit explique l'étonnant résultat d'accommodement qui en est ressorti.
Les entrepreneurs de la prise de décision : l'exemple des politiques de sécurité nationale de l'administration G. W. Bush (2001–2004)
Authors: David Charles-Philippe , Barthe Sébastien
Published: January 2014

Résumé.Comment expliquer la politique de sécurité nationale américaine, notamment l'évolution de certaines décisions en matière de politique étrangère et de sécurité intérieure ? Quels acteurs et quels facteurs rendent compte des résultats pour le moins controversés de celles-ci ? Au-delà des discours, des institutions et des énoncés, les choix de sécurité ont été l'œuvre de ceux que nous surnommons les « entrepreneurs » de la prise de décision. La question à laquelle cet article veut répondre est précisément de savoir qui sont ces « entrepreneurs » et comment ils ont réalisé cet objectif de transformation des politiques de sécurité des États-Unis. Trois prises de décision de la première administration Bush sont abordées : la guerre préventive en Irak, la redéfinition légale de la notion de torture, et l'institutionnalisation plus grande de la sécurité intérieure.

Abstract.How are we to explain U.S. foreign policy, particularly policymaking on national security and homeland security, under the first administration of G. W. Bush? Who were the actors and what were the factors that produced what were, to say the least, controversial results? Looking beyond the speeches, statements and institutions, the security decisions can be seen as the work of “policy entrepreneurs.” This article considers who those entrepreneurs were and how they achieved their goal of transforming U.S. security policy. Three decisions are discussed: the pre-emptive war in Iraq, the legal redefinition of torture by the Bush administration, and the institutionalization of homeland security, in particular thePatriot Act.
Citizenship and Gender Equality in the Second Spanish Republic: Representations and Practices in Socialist Culture (1931–1936)
Authors: AGUADO ANA
Published: January 2014

This article contributes to historiographical debates on political cultures, the construction of female citizenship and democracy development through an analysis of the construction of gender identities in socialist culture and working-class culture in Spain. From 1931, in the context of the Second Spanish Republic, socialist culture experienced a complex mixture of egalitarian proposals, collective actions and strategies to achieve the political mobilisation of women. This process reformulated in female terms many of the concepts historically present in this political culture: equality, freedom, secularism and citizenship.
The Effect of Meiji Government Policy on Traditional Japanese Music During the Nineteenth Century: The Case of the Shakuhachi
Authors: Day Kiku
Published: January 2014

The nineteenth century was the major turning point in traditional Japanese music, leading to changes in the musical world that rendered it well-nigh unrecognizable. With the introduction, in 1871, of a primary school curriculum in which only Western music was to be taught, traditional Japanese music began its journey to marginalization – in the end becoming a genre that sounded foreign to a majority of the inhabitants of its own native country.

The vertical bamboo flute shakuhachi was particularly affected by the new Meiji government's modernization process. During the Edo period (1603–1867), mendicant monks organized in the Fuke sect had enjoyed a monopoly on playing the instrument. With the abolishment of the sect, in 1871, and the prohibition of begging for the following decade, the social position of shakuhachi players was radically changed. This article explores the ways in which shakuhachi players adapted to these changes in order to survive. That adaptation affected not only the construction of the instrument, but also the music itself.
Galactic Astronomy: Past, Present & Future A Personal View
Authors: Andersen Johannes
Published: January 2014

This closing contribution is structured as a tour of developments of Galactic astronomy over the last forty years, seen from an entirely personal viewpoint. On this background, I try to place some of the current developments in context, with reference to many of the key contributions to this meeting, and speculate where we may be heading in the near future.
A review of the chemical abundances and kinematics of the Galactic bulge
Authors: Origlia Livia
Published: January 2014

This review will attempt to draw astate of the artobservational picture of the Galactic bulge. The main chemical, kinematic and evolutionary properties of the gas and stellar populations in the barred bulge and towards the Galactic center region will be discussed in the context of the possible formation scenarios. Future perspectives for our comprehension of the complex structure of the Galactic bulge from ongoing and foreseen optical and infrared surveys will be also highlighted.
Chemodynamical Simulations of the Milky Way Galaxy - Inhomogeneous Chemical Enrichment
Authors: Kobayashi Chiaki
Published: January 2014

The predictions of our chemodynamical simulations from cosmological initial conditions are as follows: The disk formed Inside-out. Metallicity radial and vertical gradients exist, but no [α/Fe] radial gradient. Metallicity radial gradient is steeper at higher redshifts. The [α/Fe]-[Fe/H] relation is caused by the delayed enrichment of Type Ia supernovae (not with long lifetimes, but with the metallicity effect). The bulge formed through the assembly of small gas-rich galaxies at high redshifts. [α/Fe] is higher, [Mn/Fe] is lower, [(Na, Al)/Fe] are higher than the disk. Metallicity and [α/Fe] vertical gradients exist, which is caused by the increase of metal-rich and low [α/Fe] populations at lower latitudes. Bars may form later, which may show boxy and cylindrical rotation. Half of thick disk stars (kinetically selected) come from minor mergers. [α/Fe] is higher, and [Mn/Fe] is lower than the thin disk, but [(Na, Al, Cu, Zn)/Fe] are lower than the bulge. There are metallicity vertical, weak metallicity radial, and no [α/Fe] radial gradients. It would be interesting to compare the predictions with other models such as radial mixing, disk heating, and clumpy disks.

For the solar neighborhood, the frequency distributions of elements from oxygen to zinc are in excellent agreement not only for the average values but also for the scatter. In chemodynamical simulations, chemical enrichment takes place inhomogeneously, and the scatter originates from a combination of various effects - mergers, migration, and in-situ. The inhomogeneous enrichment is important in reproducing observed nitrogen abundances, and also in understanding elemental abundance patterns of dwarf spheroidal galaxies and carbon-enhanced damped Lyman α systems.
The 3-Dimensional Distribution of Interstellar Dust
Authors: Murthy Jayant
Published: January 2014

A knowledge of the three dimensional distribution of interstellar dust is critical in interpreting all observations of the sky, particularly in the understanding of the structure and morphology of our Galaxy. It has been much easier to map the integrated dust extinction through the Galaxy, which is needed in modeling extragalactic sources, but this yields an overestimate of reddening to Galactic objects. Massive surveys, such as Gaia, present both a problem in that the distribution of interstellar dust must be known in order to model the internal structure of the Galaxy and an opportunity in that multi-color data may be used to deconvolve the dust distribution. I will present the current state of the modeling, which is yet in its early stages.
Using synthetic emission maps to constrain the structure of the Milky Way
Authors: Pettitt Alex R. , Dobbs Clare L. , Acreman David M. , Price Daniel J.
Published: January 2014

We present the current standing of an investigation into the structure of the Milky Way. We use smoothed particle hydrodynamics (SPH) to simulate the ISM gas in the Milky Way under the effect of a number of different gravitational potentials representing the spiral arms and nuclear bars, both fixed and time-dependent. The gas is subject to ISM cooling and chemistry, enabling us to track the CO and HI density. We use a 3D grid-based radiative transfer code to simulate the emission from the SPH output, allowing for the construction of synthetic longitude-velocity maps as viewed from the Earth. By comparing these maps with the observed emission in CO and HI from the Milky Way ([Dame et al. 2001, Kalberla et al. 2005]), we can infer the arm/bar geometry that provides a best fit to our Galaxy. By doing so we aim to answer key questions concerning the morphology of the Milky Way such as the number of the spiral arms, the pattern speeds of the bar(s) and arms, the pitch angle of the arms and shape of the bar(s).
What did we learn about the Milky Way during the last decade, and what shall we learn using Gaia and LSST?
Authors: Ivezić željko , Beers Timothy C. , Jurić Mario , Loebman Sarah R. , Berry Michael
Published: January 2014

Studies of stellar populations have been reinvigorated during the last decade by the advent of large-area sky surveys such as SDSS, 2MASS, RAVE, and others. These data, together with theoretical and modeling advances, are revolutionizing our understanding of the nature of the Milky Way, and galaxy formation and evolution in general. The abundance of substructure in the multi-dimensional space of various observables, such as position, kinematics, and metallicity, is by now proven beyond doubt, and demonstrates the importance of mergers in the growth of galaxies. Unlike smooth models that involve simple components, the new data reviewed here clearly exhibit many irregular structures, such as the Sagittarius dwarf tidal stream and the Virgo and Pisces overdensities in the halo, and the Monoceros stream closer to the Galactic plane. These recent developments have made it clear that the Milky Way is a complex and dynamic structure, one that is still being shaped by the merging of neighboring smaller galaxies. Here we summarize developments over the last decade in our mapping of the stellar content of the Milky Way, as well as recent attempts to map the dark matter halo by Loebman et al. (2012) and ISM dust distribution by Berry et al. (2012). We also briefly discuss the next generation of wide-field sky surveys, exemplified by Gaia and LSST, which will improve measurement precision manyfold, and comprise billions of individual stars.
3D modeling of stellar atmospheres and the impact on the understanding of the reliability of elemental abundances in stars as tracers of galactic chemical evolution
Authors: Ludwig H.-G. , Steffen M. , Bonifacio P. , Caffau E. , Kučinskas A. , Freytag B.
Published: January 2014

We present a critical review of the construction of 3D model atmospheres with emphasis on modeling challenges. We discuss the basic physical processes which give rise to the effects which set 3D models apart from 1D standard models. We consider elemental abundances derived from molecular features, and the determination of the microturbulence with 3D models. The examples serve as illustration of the limitations inherent to 1D, however, also to 3D modeling. We find that 3D models can provide constraints on the microturbulence parameter, and predict substantial corrections for abundances derived from molecular species.
Review: progress in NLTE calculations and their application to large data-sets
Authors: Mashonkina Lyudmila
Published: January 2014

One of the major tasks in interpretation of data from large-scale stellar surveys is to determine the fundamental atmospheric parameters such as effective temperature, surface gravity, and metallicity. In most on-going and upcoming projects, they are derived spectroscopically, relying on classical one-dimensional (1D) model atmospheres and the assumption of LTE. This review discusses the present achievements and problems of non-local thermodynamic equilibrium (NLTE) line-formation calculations for FGK-type stars. The topics that are addressed include (i) the construction of comprehensive model atoms for the chemical elements with complex term system, (ii) possible systematic errors inherent in classical LTE spectroscopic determinations of stellar parameters and chemical abundances, (iii) the uncertainties in final NLTE results caused by the uncertainties in atomic data, and (iv) applications of the NLTE line-formation calculations coupled to the spatial and temporal average 〈3D〉 models to spectroscopic analyses.
Data Resources and Services at CAsDC
Authors: Cui Chenzhou , He Boliang , Xiao Jian , Yu Ce , Li Jian , Cao Zihuang , Su Liying , Fan Dongwei , Qiao Cuilan , Li Changhua , Chen Yue , Wang Runtao , Zhao Yongheng
Published: January 2014

The Chinese Astronomical Data Center (CAsDC) is a member of World Data System, hosted at National Astronomical Observatories, Chinese Academy of Sciences(NAOC). The CAsDC keeps close collaboration with IVOA, WDS and CODATA. The whole set of LAMOST data, including raw data and data products, are hosted at the CAsDC. Data resources and services of the CAsDC are introduced.
A Matched-Filter Map of the 300 km/s Stream
Authors: Grillmair C. J.
Published: January 2014

We present a matched-filter, surface density map of the “300 km/s” stream recently discovered in the vicinity of the ultrafaint dwarf galaxy Segue 1.
Chemical tagging with Gaia-ESO Survey and Gaia-RVS data
Authors: Guiglion G. , Recio-Blanco A. , de Laverny P.
Published: January 2014

We present a new method devoted to chemical tagging for Galactic Archeology. In the context of the Gaia-ESO Survey (GES) and the Gaia Data Processing and Analysis Consortium (DPAC), we aim at preparing the Gaia-Radial Velocity Spectrograph analysis, which will provide ~ 2×106 spectra covering the IR CaII triplet domain (R ~ 11 500), with sufficient SNR to perform chemical tagging. Our method will be integrated in the Gaia DPAC Apsis pipeline (CU8, Astrophysical Parameters) and we test it with GES GIRAFFE spectra (MEDUSA mode, HR10 & HR21) deriving abundances of MgI in 168 stars.
Probing non-spherical dark halos in the Galactic dwarf satellites
Authors: Hayashi Kohei , Chiba Masashi
Published: January 2014

We construct axisymmetric mass models for dwarf spheroidal (dSph) galaxies in the Milky Way to obtain realistic limits on the non-spherical structure of their dark halos. This is motivated by the fact that the observed luminous parts of the dSphs are actually non-spherical and cold dark matter models predict non-spherical virialized dark halos on sub-galactic scales. Applying these models to line-of-sight velocity dispersion profiles along three position angles in six Galactic satellites, we find that the best fitting cases for most of the dSphs yield not spherical but oblate and flattened dark halos. We also find that the mass of the dSphs enclosed within inner 300 pc varies depending on their total luminosities, contrary to the conclusion of previous spherical models. This suggests the importance of considering non-spherical shapes of dark halos in dSph mass models.
An OGLE view of the bulge and Sagittarius
Authors: Jin Shoko , Grebel Eva K. , Haschke Raoul
Published: January 2014

We use observations of OGLE-III ab-type RRLyrae stars towards the Galactic centre (Soszyński et al. 2011, AcA 6,1) to study the metallicity and 3D spatial distribution of the old and metal-poor component of the Galactic bulge. Metallicities and distances to the RRLyrae stars are derived photometrically from Fourier-component analyses of their light curves, allowing the determination of distances accurate to ~7% from 0 to 40 kpc. The distance distribution of the RRLyrae stars peaks at 8.8 kpc, with the data indicating the presence of a bar-like structure inclined at ~30° to the line of sight. The dataset also exhibits a secondary concentration of stars beyond the Galactic centre at ~27 kpc. This is consistent with the distance to the Sagittarius (Sgr) dwarf galaxy, and can be attributed to the serendipitous alignment of the Sgr stream with the bulge. This dataset allows the Sgr stream to be traced in this part of the sky for the first time. The underlying metallicity distributions are determined to have mean ± intrinsic width of [Fe/H]bulge = −1.24±0.23 dex and [Fe/H]Sgr = −1.53±0.14 dex.
Binary Star Stellar Population Synthesis Model For Astrophysical Studies
Authors: Li Z. M. , Mao C. Y. , Chen L. , Zhang Q.
Published: January 2014

Binary stars possibly exists in most galaxies and star clusters. Their evolution can lead to significant change in stellar population studies. Binary star to fit group (BS2fit: ∞) has built up a binary star stellar population synthesis model and used it in a few works. This page is to introduce the model and its possible applications.
Binary White Dwarfs in the Galactic Halo
Authors: van Oirschot Pim , Nelemans Gijs , Helmi Amina , Starkenburg Else , Pols Onno , Brown Anthony G.A.
Published: January 2014

We use the stellar population synthesis code SeBa (Portegies Zwart & Verbunt (1996), Toonen, Nelemans & Portegies Zwart (2012)) to study the halo white dwarf population. Here we assume a Kroupa initial mass function and compare 4 models, varying two parameters: the star formation (SF) history of the halo (either continuous SF during 2.5 Gyr, which started 13.2 Gyr ago, or a SF burst during 360 Myr, which started 12.9 Gyr ago – see the left panel of the figure) and the binary fraction of the halo (either 100% single stars, or 100% binaries). White dwarf cooling models (Althaus et al. (2009) and Renedo et al. (2010)) allow us to plot the halo white dwarf luminosity function for these 4 models, as is done in the right panel of the figure. Combined with an assumption about the density distribution of halo stars, we will study which of these white dwarfs Gaia can see, and what that can tell us about the initial parameter distributions in the halo. In the near future, we plan to use the Munich-Groningen semi-analytical galaxy formation model (Starkenburg et al. (2013)), to obtain key ingredients for the population synthesis modeling, such as a realistic star formation history (see the left panel of the figure).
Chromospheric variabilities of M active stars based on Guoshoujing Telescope
Authors: Pi Q. F. , Zhang L. Y. , Shi J. R. , Wu H. , Zhao Y. H. , Luo A. L. , Zhao J. K. , Zhou A. Y. , Fang X. S. ,   Lamost Collaboration
Published: January 2014

For the M active catalogue of Guoshoujing Telescope (LAMOST), 933 sources are presented in at least two exposures. We found that many M active stars show chromospheric variability in the Ca II H, Hα, Hβ, and Hγ lines on short or long timescales.
Testing SME determination of stellar parameters
Authors: Ryabchikova T. A. , Mashonkina L. I. , Titarenko A. R. , Alexeeva S. A. , Pakhomov Yu. V. , Piskunov N. E. , Sitnova T. M. , Nizamov B. A.
Published: January 2014

We present the results of special tests of the automatic procedure for atmospheric parameters determination based on spectroscopy.
Statistical equilibrium of silicon in the atmospheres of cool stars
Authors: Shi J. R. , Gehren T. , Mashonkina L. , Zhao G.
Published: January 2014

The statistical equilibrium of neutral and ionized silicon in the atmospheres of cool stars is discussed. Non-local thermodynamic equilibrium effects (NLTE) are investigated. It is found that the NLTE effects for Si are important, in particular for warm metal-poor stars. For warm metal-poor stars, the NLTE abundance correction reaches ~0.2 dex relative to standard LTE calculations.
High velocity and hypervelocity stars from the companions of type Ia supernovae
Authors: Wang B. , Liu D. , Jia S. , Han Z.
Published: January 2014

The single-degenerate (SD) model is currently a favourable progenitor scenario for the production of type Ia supernovae (SNe Ia). The companion in the SD model would survive after the SN explosion. In this work, we obtained the velocity distribution of the surviving companion stars from different SD scenarios in the Galaxy, which can be verified by future observations.
The Explosive Universe with Gaia
Authors: Wyrzykowski Łukasz , Hodgkin Simon T. , Blagorodnova Nadejda , Belokurov Vasily
Published: January 2014

The Gaia mission will observe the entire sky for 5 years providing ultra-precise astrometric, photometric and spectroscopic measurements for a billion stars in the Galaxy. Hence, naturally, Gaia becomes an all-sky multi-epoch photometric survey, which will monitor and detect variability with millimag precision as well as new transient sources such as supernovae, novae, microlensing events, tidal disruption events, asteroids, among others.

Gaia data-flow allows for quick detections of anomalies within 24-48h after the observation. Such near-real-time survey will be able to detect about 6000 supernovae brighter than 19 mag up to redshifts of Z 0.15. The on-board low-resolution (R 100) spectrograph will allow for early and robust classification of transients and minimise the false-alert rate, even providing the estimates on redshift for supernovae. Gaia will also offer a unique possibility for detecting astrometric shifts in microlensing events, which, combined with Gaia's and ground-based photometry, will provide unique mass measurements of lenses, constrains on the dark matter content in the Milky Way and possible detections of free floating black holes.

Alerts from Gaia will be publicly available soon after the detection is verified and tested. First alerts are expected early in 2014 and those will be used for ground-based verification. All facilities are invited to join the verification and the follow-up effort. Alerts will be published on a web page, via Skyalert.org and via emailing list. Each alert will contain coordinates, Gaia light curve and low-resolution spectra, classification and cross-matching results.

More information on the Gaia Science Alerts can be found here: http://www.ast.cam.ac.uk/ioa/wikis/gsawgwiki/

The full version of the poster is available here: http://www.ast.cam.ac.uk/ioa/wikis/gsawgwiki/images/1/13/GaiaAlertsPosterIAUS298.pdf
The Velocity Distribution in the Solar Neighborhood from LAMOST Pilot Survey
Authors: Xia Qiran , Liu Chao , Xu Yan , Mao Shude , Gao Shuang
Published: January 2014

We use 63,774 F/G dwarf stars from the LAMOST pilot survey to explore the velocity distribution in the solar neighborhood. The intrinsic UV distribution is reconstructed with a 20-Gaussian model using extreme deconvolution. We find at least two arcs, one extending from (−106, −3) to (94, −27) km/s and the other from (29, −9) to (78, −51) km/s. The arcs are qualitatively consistent with numerical simulations of the resonance induced by the Galactic bar and can be used to constrain its dynamical properties.
Flux Calibration for LAMOST Spectroscopic Survey of the Galactic Anti-center
Authors: Xiang M.-S. , Liu X.-W. , Yuan H.-B. , Zheng Y. , Huo Z.-Y. , Huang Y. ,   LAMOST Collaboration
Published: January 2014

Unknown extinction of Galactic disk stars makes it difficult to select flux standards based on colors alone for the LAMOST Spectroscopic Survey of the Galactic Anti-center (LSS-GAC; Liu et al., this volume). To solve this problem, for each spectrograph of an LSS-GAC plate, 5 – 10 F-type stars are selected from spectroscopy-based stellar parameters (Teff, log g, [Fe/H]) and adopted as flux standards, and an iterative approach is adopted to calibrate spectra. From spectra processed with nominal response curves, stellar parameters are derived with the PKU stellar parameter pipeline, LSP3 (Liu et al., this volume). More realistic response curves are then derived by comparing the observed spectra with synthetic spectra (Munari et al. 2005). The later is reddened assuming a R=3.1 Fitzpatrick (1999) reddening law using E(B-V) obtained by comparing photometric and synthetic colors. New stellar parameters are derived from spectra reprocessed using the new response curves, iteratively. Comparison of LSS-GAC spectral colors with photometric ones yields differences on average 0.01±0.06 and −0.06±0.04 mag in g-r and r-i, respectively. The relatively large difference in r-i is caused by the fact that the current pipeline has opted to not to correct for the telluric absorption, most notably in the i-band. Comparison of multi-epoch LSS-GAC spectra indicates < 8% uncertainties in the spectral shape from 4000 to 9000 Å. The LSS-GAC seems to yields spectra of more realistic SEDs than the SDSS (DR7) at low Galactic latitudes (Fig. 1). The shape of LAMOST response curves may vary by up to 20% in a given night, and even larger for different nights, indicating that flux calibration plate by plate is essential.
Searching for extremely alpha-poor stars in the Galactic Halo
Authors: Xing Qianfan , Zhao Gang
Published: January 2014

A few alpha-poor stars that show severe departures (over 0.4 dex deficiency in alpha-element abundance) from the general enhanced alpha-element chemical abundance trends of the halo have been discovered in recent years, such as BD +80°245, G4-36 and CS 22966-043. These ratios suggest a different chemical enrichment history for these stars than for the majority of the halo. Similarly low-alpha abundance patterns are also seen in the Sagittarius dSph galaxy. We present a method for searching of extremely alpha-poor stars from low-resolution stellar spectra of LAMOST pilot survey and attempt to create a large sample of these particular Galactic halo stars.
Scandium Abundance in Metal-poor Stars
Authors: Zhang H. W. , Gehren T. , Zhao G.
Published: January 2014

The Scandium abundances for 85 metal-poor stars are presented. Our result shows that NLTE corrections for Sc II lines are small (−0.04 to +0.06 dex). The abundance trends in stars of different populations are discussed.
Plasma diagnostics of emission-line galaxies in SDSS
Authors: Zhang Zhitai , Liang Yanchun , Hammer François
Published: January 2014

Sample contains 15 019 narrow emission-line galaxies, i.e. Seyferts, LINERs, composites and star-forming galaxies, from SDSS DR7 for systematically studying differences between different classes. We report two clear sequences of electron temperature (Te) and density (ne): Te-LINER ≳ Te-composite > Te-Seyfert > Te-star-forming and ne-Seyfert ≳ ne-LINER > ne-composite > ne-star-forming. General transitions of ne and Te from central regions to disks are quantitatively confirmed.
Three Wide Binaries in LAMOST Pilot Survey
Authors: Zhao J. K. , Zhao G. , Oswalt T. D.
Published: January 2014

Three wide binary candidates that have been identified in the Large sky Area Multi-Object Spectroscopic Telescope (LAMOST) pilot survey data are presented. All three consist of main sequence stars of relatively late spectral type.
SEEDS: Strategic Explorations of Exoplanets and Disks with Subaru
Authors: Tamura Motohide ,   the SEEDS team2
Published: January 2014

SEEDS is the first Subaru Strategic Program, whose aim is to conduct a direct imaging survey for giant planets as well as protoplanetary/debris disks at a few to a few tens of AU region around 500 nearby solar-type or more massive young stars devoting 120 Subaru nights for 5 years. The targets are composed of five categories spanning the ages of ~1 Myr to ~1 Gyr. Some RV-planet targets with older ages are also observed. The survey employs the new high-contrast instrument HiCIAO, a successor of the previous NIR coronagraph camera CIAO for the Subaru Telescope. We describe the outline of this survey and present its first three years of results. The survey has published ~20 refereed papers by now. The main results are as follows: (1) detection and characterization of the most unequivocal and lowest-mass planet via direct imaging. (2) detection of a super-Jupiter around the most massive star ever imaged, (3) detection of companions around a retrograde exoplanet system, which supports the Kozai mechanism for the origin of retrograde orbit (not in this proceedings, but see Narita et al. 2010, 2012). We also report (4) the discovery of unprecedentedly detailed structures of more than a dozen of protoplanetary disks and some debris disks. The detected structures such as wide gaps and spirals arms of a Solar-system scale could be signpost of planet.
Search for cool extrasolar giant planets combining coronagraphy, spectral and angular differential imaging
Authors: Maire Anne-Lise , Boccaletti Anthony , Rameau Julien , Chauvin Gaël , Lagrange Anne-Marie , Bonnefoy Mickaël , Desidera Silvano , Sylvestre Mélody , Baudoz Pierre , Galicher Raphaël , Mouillet David
Published: January 2014

Spectral differential imaging (SDI) is part of the observing strategy of current and on-going high-contrast imaging instruments on ground-based telescopes. Although it improves the star light rejection, SDI attenuates the signature of off-axis companions to the star, just like angular differential imaging (ADI). However, the attenuation due to SDI has the peculiarity of being dependent on the spectral properties of the companions. To date, no study has investigated these effects. Our team is addressing this problem based on data from a direct imaging survey of 16 stars combining the phase-mask coronagraph, the SDI and the ADI modes of VLT/NaCo. The objective of the survey is to search for cool (Teff<1000-1300 K) giant planets at separations of 5-10 AU orbiting young, nearby stars (<200 Myr, <25 pc). The data analysis did not yield any detections. As for the estimation of the sensivity limits of SDI-processed images, we show that it requires a different analysis than that used in ADI-based surveys. Based on a method using the flux predictions of evolutionary models and avoiding the estimation of contrast, we determine directly the mass sensivity limits of the survey for the ADI processing alone and with the combination of SDI and ADI. We show that SDI does not systematically improve the sensitivity due to the spectral properties and self-subtraction of point sources.
Successes and challenges of the APP Coronagraph
Authors: Kenworthy Matthew A. , Quanz Sascha , Otten Gilles , Meshkat Tiffany , Codona Johanan , Snik Frans , Meyer Michael E. , Kasper Markus , Girard Julien
Published: January 2014

The Apodizing Phase Plate (APP) coronagraph has been used to image the exoplanet β Pictoris b and the protoplanet candidate around HD 100546, and is currently in use in surveys with NaCo at the VLT. Its success is due to its tolerance to tip-tilt pointing errors in current AO systems, which degrade the performance of nearly all other coronagraphs. Currently the sensitivity of the APP is limited by non-common path errors in the science camera systems and by its chromatic behaviour. We present the achromatized Vector APP coronagraph and address how we will measure and minimise non-common path errors with Focal Plane Wavefront Sensing algorithms.
Companion search around β Pictoris with the newly commissioned L'-band vector vortex coronagraph on VLT/NACO
Authors: Mawet D. , Absil O. , Milli J. , Baudoz P. , Boccaletti A. , Chauvin G. , Delacroix C. , Girard J. H. , Lagrange A. M. , O'Neal J. , Bourget P. , Forsberg P. , Gonte F. , Habraken S. , Hanot C. , Karlsson M. , Kasper M. , Lizon J.-L. , Muzic K. , Olivier R. , Peña E. , Slusarenko N. , Tacconi-Garman L. E. , Surdej J.
Published: January 2014

Here we present the installation and successful commissioning of an L'-band Annular Groove Phase Mask (AGPM) coronagraph on VLT/NACO. The AGPM is a vector vortex coronagraph made from diamond subwavelength gratings tuned to the L' band. The vector vortex coronagraph enables high contrast imaging at very small inner working angle (here 0″.09, the diffraction limit of the VLT at L'), potentially being the key to a new parameter space. During technical and science verification runs, we discovered a late-type companion at two beamwidths from an F0V star (Mawet et al. 2013), and imaged the inner regions of β Pictoris down to the previously unexplored projected radius of 1.75 AU. The circumstellar disk was also resolved from ≃ 1″ to 5″ (see J. Milli et al., these proceedings). These results showcase the potential of the NACO L-band AGPM over a wide range of spatial scales.
Debris Disk Science with the Palomar ExAO System: First Results
Authors: Wahl Matthew , Metchev Stanimir , Patel Rahul , Serabyn Eugene , Mawet Dimitri , Dekany Richard , Roberts Jennifer , Burruss Rick , Bouchez Antonin , Truong Tuan , Baranec Christoph , Guiwits Stephen , Hale David , Angione John , Trinh Thang , Zolkower Jeffry , Shelton J. Christopher , Palmer Dean , Henning John , Croner Ernest , Troy Mitchell , McKenna Dan , Tesch Jonathan
Published: January 2014

We present first imaging results from the PALM-3000 adaptive optics system and PHARO camera on the Hale 5 m telescope. Observations using a vector vortex coronagraph have given us direct detections of the two-ring dusty debris system around the star HD 141569. Our observations reveal the inner clearing in the disk to unprecedentedly small angular separations, and are the most sensitive yet at the H and K bands. We are for the first time able to measure and compare the colors of the scattered light in the inner and outer dust rings, and find that the outer ring is significantly bluer than the inner ring.
Radio Interferometry Observations of the Hallmarks of Planet Formation
Authors: Andrews Sean M.
Published: January 2014

Some of the fundamental processes involved in the evolution of circumstellar disks and the assembly of planetary systems are just now becoming accessible to astronomical observations. The new promise of observational work in the field of planet formation makes for a very dynamic research scenario, which is certain to be amplified in the coming years as the revolutionary Atacama Large Millimeter/submillimeter Array (ALMA) facility ramps up to full operations. To highlight the new directions being explored in these fields, this brief review will describe how high angular resolution measurements at millimeter/radio wavelengths are being used to study several crucial aspects of the formation and early evolution of planetary systems, including: the gas and dust structures of protoplanetary disks, the growth and migration of disk solids, and the interactions between a young planetary system and its natal, gas-rich disk.
Panchromatic imaging and modeling of SSTtau J042021+281349: A new prototypical edge-on protoplanetary disk
Authors: Duchêne G. , Stapelfeldt K. , Isella A. , Perrin M. , Ménard F. , Padgett D. , Pinte C. , Wolff S. , Krist J. , Ghez A. , Konopacky Q.
Published: January 2014

We present new high-resolution observations and modeling of SSTtau J042021+ 281349, a 400 AU-radius edge-on protoplanetary disk. We have gathered visible and near-infrared scattered light images of the system with the Hubble Space Telescope and Keck adaptive optics system, as well as a 1.3 mm continuum map with CARMA. Compared to the well-known HH 30 disk, this new system is remarkable because of its spectacular bipolar jet and the high degree of lateral symmetry of the disk. Indeed, we argue that this system is a “cleaner” prototype for edge-on disks. In addition, the apparent achromaticity of dust properties (most notably the almost grey opacity law) from the visible to the near-infrared in this disk suggests that it is in an advanced stage of dust evolution.
Circumstellar Disks in Very Young Embedded Clusters
Authors: Mariñas Naibí , Lada Elizabeth A. , Teixeira Paula S. , Lada Charles J.
Published: January 2014

We used FLAMINGOS near-IR photometry and spectroscopy and Spitzer mid-IR photometry to study disk fractions in the 1 to 2 Myr old NGC2264 clusters. We find that stars with masses < 0.3 solar masses have lower disk fractions than stars of solar mass or higher at these early ages. We also find that most disks disappear within the first 4 Myr, which is consistent with previous studies of disk lifetimes. Our study suggests that either some very low mass stars form without disks or that their disks are less massive and/or colder than predicted from models and not detected with Spitzer/Flamingos sensitivities.
Large grains can grow in circumstellar discs
Authors: Meru Farzana , Galvagni Marina , Olczak Christoph , Garaud Pascale
Published: January 2014

We perform coagulation & fragmentation simulations to understand grain growth in T Tauri & brown dwarf discs. We present a physically-motivated approach using a probability distribution function for the collision velocities and separating the deterministic & stochastic velocities. We find growth to larger sizes compared to other models. Furthermore, if brown dwarf discs are scaled-down versions of T Tauri discs (in terms of stellar & disc mass, and disc radius), growth at the same location with respect to the outer edge occurs to similar sizes in both discs.
The bright end of the exo-Zodi luminosity function: Disk evolution and implications for exo-Earth detectability
Authors: Kennedy G. M. , Wyatt M. C.
Published: January 2014

This contribution summarises the first characterisation of the 12 μm warm dust (“exo-Zodi”) luminosity function around Sun-like stars, focussing on the dustiest systems that can be identified by the WISE mission (Kennedy & Wyatt 2013). We use the sample of main-sequence stars observed by Hipparcos within 150pc as an unbiased sample, and report the detection of six new warm dust candidates. The ages of five of these new sources are unknown, meaning that they may be sites of terrestrial planet formation or rare analogues of other old warm dust systems. We show that the dustiest old (> Gyr) systems such as BD+20 307 are 1 in 10,000 occurrences. Bright warm dust is much more common around young (<120 Myr) systems, with a ~1% occurrence rate. We show that a two component in situ model where all stars have initially massive warm disks and in which warm debris is also generated at some random time along the stars' main-sequence lifetime, perhaps due to a collision, can explain the observations. However, if all stars only have initially massive warm disks these would not be visible at Gyr ages, and random collisions on the main-sequence are too infrequent to explain the high disk occurrence rate for young stars. That is, neither component can explain the observations on their own. Despite these conclusions, we cannot rule out an alternative dynamical model in which comets are scattered in from outer regions because the distribution of systems with the appropriate dynamics is unknown. Our in situ model predicts that the fraction of stars with exo-Zodi bright enough to cause problems for future exo-Earth imaging attempts is at least roughly 10%, and is higher for populations of stars younger than a few Gyr. This prediction of roughly 10% also applies to old stars because bright systems like BD+20 307 imply a population of fainter systems that were once bright, but are now decaying through fainter levels. Our prediction should be strongly tested by the Large Binocular Telescope Interferometer, which will provide valuable constraints and input for more detailed evolution models. A detection fraction lower than our prediction could indicate that the hot dust in systems like BD+20 307 has a cometary origin due to the quirks of the planetary dynamics. Population models of comet delivery need to be developed to help distinguish between different possible origins of warm dust.