bluuebunny/crossref_metadata_2025_split huggingface dataset:
Insect-based compost and vermicompost production, quality and performance
Authors: Piñero Jaime C. , Shivers Traron , Byers Patrick L. , Johnson Hwei-Yiing 
Published: August 2018

AbstractIn an attempt to utilize large amounts of Japanese beetles, Popillia japonica (Coleoptera: Scarabaeidae) that were captured using a mass trapping system, compost using Japanese beetle carcasses was prepared with the layer method. Carbon sources included shredded paper, wood chips and leaves, while the sole nitrogen source was frozen Japanese beetles. In addition, Japanese beetle-based vermicompost was prepared in the greenhouse by mixing the Japanese beetle-based compost with sphagnum peat moss and moist shredded paper and exposing this mixture to composting earthworms (Eisenia fetida). Chemical analyses of the Japanese beetle carcasses indicated that 10.8% of their body weight is nitrogen (N). Analyses of the resulting Japanese beetle-based compost and vermicompost indicated that both types of materials are good quality soil amendments. Greenhouse studies were conducted to quantify the effects of varying proportions of Japanese beetle-based vermicompost and compost mixed with a potting medium and varying dosages of synthetic fertilizer 20-0-0, on mean fresh and dry weight of lettuce shoots and leaf area. Japanese beetle-based compost and vermicompost increased lettuce biomass to an extent that was comparable with the addition of synthetic N-based fertilizer. A mixture of 15 and 30% of each compost type with potting media significantly increased plant weight and leaf area compared with potting medium alone. Results indicate that composting and vermicomposting insect carcasses are a simple, effective and affordable method to augment fertilization in support of organic production.
On the claimed X-shaped structure in the Milky Way bulge
Authors: Han Daniel , Lee Young-Wook 
Published: August 2018

AbstractA number of recent studies have claimed that the double red clump observed in the Milky Way bulge is a consequence of an X-shaped structure. In particular, Ness &amp; Lang (2016) report a direct detection of a faint X-shaped structure in the bulge from the residual map of the Wide-Field Infrared Survey Explorer (WISE) image. Here we show, however, that their result is seriously affected by a bulge model subtracted from the original image. When a boxy bulge model is subtracted, instead of a simple exponential bulge model as has been done by Ness &amp; Lang, we find that most of the X-shaped structure in the residuals disappears. Furthermore, even if real, the stellar density in the claimed X-shaped structure is way too low to be observed as a strong double red clump (dRC) at l = 0°.
Dynamical imprint of interstellar gas on persistence of spiral structure in galaxies
Authors: Ghosh Soumavo , Jog Chanda J. 
Published: August 2018

AbstractThe persistence of the spiral structure in disk galaxies has long been debated. In this work, we investigate the dynamical influence of interstellar gas on the persistence of the spiral arms in disk galaxies. We show that the gas helps the spiral arms to survive for longer time-scale (~ a few Gyr). Also, we show that the addition of gas in calculation is necessary for getting a stable density wave corresponding to the observed pattern speed of the spiral arms.
NIHAO-UHD: High-resolution Simulations of MW mass galaxies
Authors: Buck Tobias , Macciò Andrea , Ness Melissa , Obreja Aura , Dutton Aaron 
Published: August 2018

AbstractHigh resolution cosmological and hydrodynamical simulations have reached a resolution able to resolve in a self consistent way the disc of our galaxy, the galaxy center and the satellites orbiting around it. We present first results from the NIHAO-UHD project, a set of very high-resolution baryonic zoom-in simulations of Milky Way mass disc galaxies. These simulations model the full cosmological assembly history of the galaxies and their satellite system using the same, well tested physics as the NIHAO project. We show that these simulations can self-consistently reproduce the observed kinematical and morphological features of the X-shaped bulge observed in our own Milky Way.
Distribution functions for Galactic disc stellar populations in the presence of non-axisymmetric perturbations
Authors: Famaey B. , Monari G. , Siebert A. , Fouvry J.-B. , Binney J. 
Published: August 2018

AbstractThe present-day response of a Galactic disc stellar population to a non-axisymmetric perturbation of the potential, in the form of a bar or spiral arms, can be treated, away from the main resonances, through perturbation theory within the action-angle coordinates of the unperturbed axisymmetric system. The first order moments of such a perturbed distribution function (DF) in the presence of spiral arms give rise to non-zero radial and vertical mean stellar velocities, called breathing modes. Such an Eulerian linearized treatment however diverges at resonances. The Lagrangian approach to the impact of non-axisymmetries at resonances avoids this problem. It is based on the construction of new orbital tori in the resonant trapping region, which come complete with a new system of angle-action variables. These new tori can be populated by phase-averaging the unperturbed DF over the new tori. This boils down to phase-mixing the DF in terms of the new angles, such that the DF for trapped orbits only depends on the new set of actions. This opens the way to quantitatively fitting the effects of the bar and spirals to Gaia data with an action-based DF.
Quenching in gas-rich Milky Way-type galaxies
Authors: Khoperskov S. , Haywood M. , Di Matteo P. , Lehnert M. , Combes F. 
Published: August 2018

AbstractTo explore the relation between bar formation and star formation in Milky Way-type galaxies quantitatively, we simulated gas-rich disk isolated galaxies. We find that the action of the stellar bar efficiently quenches star formation, reducing the star-formation rate by a factor of 10 in less than 1 Gyr. Analytical and self-consistent galaxy simulations with bars suggest that the action of the stellar bar increases the gas random motions within the co-rotation radius of the bar. Indeed, we detect an increase in the gas velocity dispersion at the end of the bar formation phase. The star formation efficiency decreases rapidly, and in all of our models, the bar quenches the star formation in the galaxy. The star-formation efficiency is much lower in simulated barred compared to unbarred galaxies and more rapid bar formation implies more rapid quenching.
Kinematic and Chemical Analysis of AEGIS Survey Stars
Authors: Dietz Sarah , Beers Timothy C. , Placco Vinicius M. , Yoon Jinmi ,   The AEGIS Collaboration
Published: August 2018

AbstractThe AAOmega Evolution of Galactic Structure (AEGIS) survey (P.I. Keller) was a moderate scale (45 nights) spectroscopic survey carried out with the AAOmega multi-fiber spectrograph at the Anglo-Australian Telescope. The input catalogue for the spectroscopic observations was derived from photometry of approximately 200 two-degree diameter fields obtained during the commissioning of the SkyMapper survey. The data consists of medium-resolution (R ~ 2,000) spectroscopy for approximately 70,000 thick disk and halo stars spanning a survey footprint of 4,900 square degrees. We plan to use the AEGIS data to further characterize the properties of the disk and halo systems and better constrain the assembly history of the Galaxy based on the behavior of the CEMP-no and CEMP-s stars in the sample.
Measurement of [Fe/H] and [C/Fe] for Metal-Poor Stars from the RAVE Survey
Authors: Rasmussen Kaitlin C. , Beers Timothy C. , Placco Vinicius M. , Yoon Jinmi , Dietz Sarah 
Published: August 2018

AbstractThe RAVE survey obtains moderate-resolution (R ~ 7500) spectroscopy of relatively bright stars in the region of the Ca triplet, and derives estimates of stellar atmospheric parameters (Teff, log g, and [Fe/H]) and abundance estimates for a limited number of elements. The RAVE sample is selected on apparent magnitude, effectively removing the biases typically associated with searches for metal-poor stars such as metallicity, evolutionary status, or Galactic population membership. For the past several years, we have been obtaining medium-resolution (R ~ 1800) spectroscopy over a much wider wavelength range, from 3700 Å to 5500 Å, for RAVE stars with estimated metallicities from the RAVE pipeline of [Fe/H] &lt; −1.8.Based on these observations, we use the well-tested n-SSPP pipeline to obtain atmospheric parameter estimates, as well as measurements of [C/Fe], for over 1,700 metal-poor star candidates. We present an analysis of the distribution of carbon-enhancement in the relatively local volume of the Galaxy as a function of metallicity, location, and kinematics. Our results are useful to test the RAVE parameter estimates, and add to the growing number of known carbon-enhanced metal-poor (CEMP) stars for future high-resolution follow-up.
Synergies between the VVVX Survey and the S-PLUS Galactic Survey
Authors: Saito Roberto K. , Minniti Dante , de Oliveira Claudia Mendes 
Published: August 2018

AbstractTwo new Galactic Surveys started activities in 2016: the ESO Public VISTA Variables in the Vía Láctea eXtended Survey (VVVX) and the Southern Photometric Local Universe Survey Galactic Survey (S-PLUS GS). VVVX is the extension of the ESO VVV Survey ((Minniti et al. 2010) and will triple the observed area from 562 deg2 to 1700 deg2. The S-PLUS GS makes use of the T80-South robotic telescope in Cerro Tololo (Chile) to observe 1420 deg2 of the Galactic disk and bulge in the optical. The S-PLUS GS will cover 800 deg2 contemporaneously and overlapping with VVVX. Here we explore the synergy between these ongoing surveys and present illustrative examples combining the optical and infrared data.
The GOTHAM survey: chemical evolution of Milky Way globular clusters
Authors: Dias Bruno , Barbuy Beatriz , Saviane Ivo , Held Enrico V. , Da Costa Gary , Ortolani Sergio , Gullieuszik Marco 
Published: August 2018

AbstractMilky Way globular clusters are excellent laboratories for stellar population detailed analysis that can be applied to extragalactic environments with the advent of the 40m-class telescopes like the ELT. The globular cluster population traces the early evolution of the Milky Way which is the field of Galactic archaeology. We present our GlObular clusTer Homogeneous Abundance Measurement (GOTHAM) survey. We derived radial velocities, Teff, log(g), [Fe/H], [Mg/Fe] for red giant stars in one third of all Galactic globular clusters that represent well the Milky Way globular cluster system in terms of metallicity, mass, reddening, and distance. Our method is based on low-resolution spectroscopy and is intrinsically reddening free and efficient even for faint stars. Our [Fe/H] determinations agree with high-resolution results to within 0.08 dex. The GOTHAM survey provides a new metallicity scale for Galactic globular clusters with a significant update of metallicities higher than [Fe/H] &gt; -0.7. We show that the trend of [Mg/Fe] with metallicity is not constant as previously found, because now we have more metal-rich clusters. Moreover, peculiar clusters whose [Mg/Fe] does not match Galactic stars for a given metallicity are discussed. We also measured the CaII triplet index for all stars and we show that the different chemical evolution of Milky Way open clusters, field stars, and globular clusters implies different calibrations of calcium triplet to metallicity.
Closing remarks and Outlook
Authors: Combes Francoise 
Published: August 2018

AbstractSome highlights are given of the IAU Symposium 334, Rediscovering our Galaxy, held in Potsdam, in July 2017: from the first stars fossil records found in the halo, the carbon-enhanced metal poor CEMP-no, to the cosmological simulations presenting possible scenarios for the Milky Way formation, passing through the chemo-dynamical models of the various components, thin and thick disks, box/peanut bulge, halo, etc. The domain is experiencing (or will be in the near future) huge improvements with precise and accurate stellar ages, provided by astero-seismology, precise stellar distances and kinematics (parallaxes and proper motions from GAIA), and the big data resulting from large surveys are treated with deep learning algorithms.
Astrometric Galactic maser measurements cross-matched with Gaia
Authors: Quiroga-Nuñez L. H. , van Langevelde H. J. , Reid M. J. , Sjouwerman L. O. , Pihlström Y. M. , Brown A. G. A. , Green J. A. 
Published: August 2018

AbstractUsing the VLBA, the BeSSeL survey has provided distances and proper motions of young massive stars, allowing an accurate measure of the Galactic spiral structure. By the same technique, we are planning to map the inner Galaxy using positions and velocities of evolved stars (provided by the BAaDE survey). These radio astrometric measurements (BeSSeL and BAaDE) will be complementary to Gaia results and the overlap will provide important clues on the intrinsic properties and population distribution of the stars in the bulge.
Chemo-Kinematic Properties of the Galactic Disk with SEGUE G and K Dwarfs: Constraints on Formation
Authors: Han Doori , Lee Young Sun , Kim Young Kwang , Beers Timothy C. 
Published: August 2018

AbstractWe present the derived kinematic characteristics of low-α thin-disk and high-α thick-disk stars in the Milky Way, investigated with a sample of about 32,000 G- and K-type dwarfs from the Sloan Extension for Galactic Understanding and Exploration (SEGUE). Based on the level of α-element enhancement as a function of [Fe/H], we separate our sample into thin- and thick-disk stars and then derive mean velocities, velocity dispersions, and velocity gradients for the U, V, and W velocity components, respectively, as well as the orbital eccentricity distribution. There are notable gradients in the V velocity over [Fe/H] in both populations: −23 km s−1 dex−1 for the thin disk and +44 km s−1 dex−1 for the thick disk. The velocity dispersion of the thick disk decreases with increasing [Fe/H], while the velocity dispersion gradient over [Fe/H] for the thin disk is almost flat for all velocity components, except for the W velocity dispersion of the metal-poor thin-disk stars. The eccentricity distribution exhibits a peak at a higher value, and is more symmetric as [α/Fe] increases, implying that complex formation mechanisms may be involved. Our results can be used to constrain several proposed disk-formation scenarios of the Milky Way and other large spirals.
Small Variation of the NIR and MIR Interstellar Extinction Laws
Authors: Gao Jian , Jiang B. W. , Xue Mengyao 
Published: August 2018

AbstractUsing the data from APOGEE, WISE, and GLIMPSE, we explored the variation of the near-infrared (NIR) and mid-infrared (MIR) interstellar extinction laws of the Milky Way. We derived the IR extinction laws towards a number of different sightlines, including 24 bins along Galactic latitude (b) and 592 plates observed by APOGEE. Our results indicate that E(J-H)/E(J-K) show only subtle variation along b, Galactic longitude (l), or the depth of E(J-K). This suggests that the NIR extinction law can be considered as universal. Similarly, E(K-W1, W2, W3, [3.6], [4.5], [5.8], [8.0])/E(J-K) also show only small variation along b, l, or the extinction depth. The MIR extinction curve is flat, indicating that the MIR extinction law is likely universal.
The IMF in the Galactic Disk and Bulge are Indistinguishable
Authors: Wegg Christopher , Gerhard Ortwin , Portail Matthieu 
Published: August 2018

AbstractWe have measured the IMF of the inner Galaxy using ~3000 OGLE-III microlensing events. Each event’s timescale depends on both the lens mass, and the velocities and distances of the lens and source. New dynamical models were used provide the distribution of distances and velocities, and thereby measure the lens mass distribution. Using a power-law or log-normal parameterisation the resultant IMF is indistinguishable from local measurements by Kroupa or Chabrier respectively. The lenses lie in the inner Galaxy where the stars are mostly ~10 Gyr old and formed on a fast α-element enhanced timescale thereby constraining IMF variability with the properties of the collapsing gas cloud. Furthermore microlensing measures the stellar mass budget, including dark remnants, to low mass. Stars contribute most of the mass in the inner Galaxy with a low fraction remaining for dark matter. Reconciling this with local dark matter estimates requires a core or shallow cusp in its profile.
Chemical tagging experiment with the Gaia-ESO open clusters
Authors: Smiljanic Rodolfo ,   the
Published: August 2018

AbstractStars observed in the field of an open cluster are ideal for a controlled test of chemical tagging. Using chemical tagging, one should identify the cluster members, i.e., those stars of similar chemical composition, if their composition is indeed different from that of all the non-member stars of the field. Moreover, the abundance-based membership can be checked against membership based on radial velocities and proper motions. Here, I report preliminary results of such an experiment using data from the Gaia-ESO Survey. Although the three membership criteria usually agree, a few interesting examples of discrepant membership classification have been found. In addition, the mean composition of each open cluster was compared to a sample of 1 600 Gaia-ESO field stars. Some cases of field stars with abundances matching those of the open clusters were identified. This experiment suggests that open clusters do not necessarily have unique abundance patterns that set them apart from all other clusters.
Stellar Substructure in the Halos of the Milky Way and M31
Authors: Ferguson Annette M. N. 
Published: August 2018

AbstractDedicated wide-field surveys have uncovered a variety of debris features and stellar streams in the halos of the Milky Way and M31. I briefly compare these perspectives and discuss how observations of the peripheral regions of M31 can help shape our current understanding of the Milky Way. Much complexity resides in the outer halos of both systems in terms of overlapping structures, and I conclude by briefly highlighting some ongoing work to characterise a narrow tidal stream in the vicinity of the ultra-faint satellite Segue 1.
Binarity in CEMP-no stars
Authors: Arentsen Anke , Starkenburg Else , Shetrone Matthew D. , McConnachie Alan W. , Depagne Éric , Venn Kim A. 
Published: August 2018

AbstractWe monitor a sample of CEMP-no stars using the CFHT and SALT telescopes to gain additional knowledge about the possible binarity of these stars. This information is valuable for each individual star, and additionally it could be used to further constrain their binary fraction. We find two new CEMP-no binaries and four additional CEMP-no stars that show some indication of radial velocity variations, resulting in a CEMP-no binary fraction of ~20%.
The effects of the selection function on metallicity trends in spectroscopic surveys of the Milky Way
Authors: Nandakumar G. , Schultheis M. , Hayden M. , Rojas-Arriagada A. , Kordopatis G. , Haywood M. 
Published: August 2018

AbstractWe investigate here the effect of the selection function on the metallicity distribution function (MDF) as well as on the vertical metallicity gradient by studying similar lines-of-sight using four different spectroscopic surveys (APOGEE, LAMOST, RAVE and Gaia-ESO) which have different targeting strategies and therefore different selection functions. We create mock fields for each survey using two stellar population synthesis models, GALAXIA and TRILEGAL. The effects of the selection function are studied in detail by applying the selection function to the two models and comparing the MDF as well as vertical metallicity gradients of the selected sources with that of the underlying sample. We find a negligible selection function effect on the MDF as well as on the vertical metallicity gradients for APOGEE, RAVE and LAMOST, and estimate a mean vertical metallicity gradient of -0.241±0.028 dex kpc−1.
ESO Spectroscopic Facility
Authors: Pasquini Luca , Delabre B. , Ellis R. S. , Marrero J. , Cavaller L. , de Zeeuw Tim 
Published: August 2018

AbstractWe present the concept of a novel facility dedicated to massively-multiplexed spectroscopy. The telescope has a very wide field Cassegrain focus optimised for fibre feeding. With a Field of View (FoV) of 2.5 degrees diameter and a 11.4m pupil, it will be the largest etendue telescope. The large focal plane can easily host up to 16.000 fibres. In addition, a gravity invariant focus for the central 10 arc-minutes is available to host a giant integral field unit (IFU). The 3 lenses corrector includes an ADC, and has good performance in the 360-1300 nm wavelength range. The top level science requirements were developed by a dedicated ESO working group, and one of the primary cases is high resolution spectroscopy of GAIA stars and, in general, how our Galaxy formed and evolves. The facility will therefore be equipped with both, high and low resolution spectrographs. We stress the importance of developing the telescope and instrument designs simultaneously. The most relevant R&amp;D aspect is also briefly discussed.
Efficiency and success rates of the Pristine survey from spectroscopic follow-up
Authors: Youakim Kris , Starkenburg Else , Aguado David , Martin Nicolas ,   the Pristine collaboration
Published: August 2018

AbstractThe Pristine survey uses narrow-band photometry on the region of the Ca II H &amp; K absorption lines to find extremely metal-poor stars. With a spectroscopic follow-up sample of 205 stars in the magnitude range 14 &lt; V &lt; 18, we compute the success rates for finding extremely metal-poor stars and modify the selection criteria used to select stars for follow-up. This reduces the sample to 149 stars, and from these we report success rates of 22% for recovering stars with [Fe/H] &lt; −3.0 and 70% for [Fe/H] &lt; −2.5. When compared to previous works that search for extremely metal-poor stars, the success rates of Pristine
show an improvement in efficiency by a factor of ~4 − 5.
Galactic Archeology with RAVE and TGAS
Authors: Steinmetz Matthias ,   the RAVE collaboration
Published: August 2018

AbstractThe 5th RAVE data release is based on 520,781 spectra (R ≈ 7500 in the CaT region at 8410 - 8795Å) of 457,588 unique stars. RAVE DR5 provides radial velocities, stellar parameters and individual abundances for up to seven elements and distances found using isochrones for a considerable subset of these objects. In particular, RAVE DR5 has 255,922 stellar observations that also have parallaxes and proper motions from the Tycho-Gaia astrometric solution (TGAS) in Gaia DR1. The combination of RAVE and TGAS thus provides the currently largest overlap of spectroscopic and space-based astrometric data and thus can serve as a formidable preview of what Gaia is going to deliver in coming data releases. Basic properties of the RAVE+TGAS survey and its derived data products are presented as well as first applications w.r.t wave-like patterns in the disk structure. An outlook to the 6th RAVE data release is given.
Precise distances to red giant stars with seismic data using the near-IR surface-brightness relation
Authors: Storm Jesper , Graczyk Dariusz , Valentini Marica , Anders Friedrich , Chiappini Cristina , Gieren Wolfgang , Pietrzynski Grzegorz 
Published: August 2018

AbstractThe Kepler and CoRoT satellites have determined precise asteroseismic radii for large samples of red giant stars. Combining these data with data from spectroscopic and photometric surveys has led to precise distance determinations using comprehensive Bayesian methods. Here we determine angular diameters and thus distances using the interferometrically calibrated near-IR surface-brightness method finding good agreement with previous results. The method can easily be reversed when accurate Gaia parallaxes for these stars become available to calibrate the asteroseismic scaling relations.