bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the 600 °C isothermal section of the Fe–Al–Ce ternary system
Authors: Zheng Huiyun , Li Zhi , Ji Li , Yin Fucheng 
Published: January 2017

AbstractThe isothermal section of the Fe–Al–Ce system at 600 °C was determined by means of scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray powder diffraction. Twenty three-phase regions were confirmed experimentally, and two three-phase regions could be deduced in this section. Five ternary compounds, i. e., τ1, τ2, τ3, τ5, and τ6, exist at 600 °C. The Fe2Ce phase contains 6.6 at.% Al in the Fe–Al–Ce system. The Fe solubility in α-Al, αAl11Ce3, αAl3Ce, Al2Ce, AlCe, and AlCe3 is approximately 1.7 at.%, 1.1 at.%, 1.2 at.%, 1.3 at.%, 5.8 at.%, and 0.1 at.%, respectively, and the solubility of Ce in α-Al, FeAl3, Fe2Al5, FeAl2, and FeAl is approximately 0.1 at.%, 1.2 at.%, 1.9 at.%, 0.9 at.%, and 3.7 at.%, respectively.
ROBO-AO KEPLER PLANETARY CANDIDATE SURVEY. III. ADAPTIVE OPTICS IMAGING OF 1629 KEPLER EXOPLANET CANDIDATE HOST STARS
Authors: Ziegler Carl , Law Nicholas M. , Morton Tim , Baranec Christoph , Riddle Reed , Atkinson Dani , Baker Anna , Roberts Sarah , Ciardi David R. 
Published: January 2017

ABSTRACT
The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging to search for blended nearby stars, which may be physically associated companions and/or responsible for transit false positives. In this paper, we present the results of our search for stars nearby 1629 Kepler planet candidate hosts. With survey sensitivity to objects as close as ∼0.″15, and magnitude differences Δm

, we find 223 stars in the vicinity of 206 target KOIs; 209 of these nearby stars have not been previously imaged in high resolution. We measure an overall nearby-star probability for Kepler planet candidates of

at separations between 0.″15 and 4.″0. Particularly interesting KOI systems are discussed, including 26 stars with detected companions that host rocky, habitable zone candidates and five new candidate planet-hosting quadruple star systems. We explore the broad correlations between planetary systems and stellar binarity, using the combined data set of Baranec et al. and this paper. Our previous 2σ result of a low detected nearby star fraction of KOIs hosting close-in giant planets is less apparent in this larger data set. We also find a significant correlation between detected nearby star fraction and KOI number, suggesting possible variation between early and late Kepler data releases.
THE COLOR–MAGNITUDE DISTRIBUTION OF HILDA ASTEROIDS: COMPARISON WITH JUPITER TROJANS
Authors: Wong Ian , Brown Michael E. 
Published: January 2017

Abstract
Current models of solar system evolution posit that the asteroid populations in resonance with Jupiter are comprised of objects scattered inward from the outer solar system during a period of dynamical instability. In this paper, we present a new analysis of the absolute magnitude and optical color distribution of Hilda asteroids, which lie in 3:2 mean-motion resonance with Jupiter, with the goal of comparing the bulk properties with previously published results from an analogous study of Jupiter Trojans. We report an updated power-law fit of the Hilda magnitude distribution through H = 14. Using photometric data listed in the Sloan Moving Object Catalog, we confirm the previously reported strong bimodality in visible spectral slope distribution, indicative of two subpopulations with differing surface compositions. When considering collisional families separately, we find that collisional fragments follow a unimodal color distribution with spectral slope values consistent with the bluer of the two subpopulations. The color distributions of Hildas and Trojans are comparable and consistent with a scenario in which the color bimodality in both populations developed prior to emplacement into their present-day locations. We propose that the shallower magnitude distribution of the Hildas is a result of an initially much larger Hilda population, which was subsequently depleted as smaller bodies were preferentially ejected from the narrow 3:2 resonance via collisions. Altogether, these observations provide a strong case supporting a common origin for Hildas and Trojans as predicted by current dynamical instability theories of solar system evolution.
MASS CONSTRAINTS OF THE WASP-47 PLANETARY SYSTEM FROM RADIAL VELOCITIES
Authors: Sinukoff Evan , Howard Andrew W. , Petigura Erik A. , Fulton Benjamin J. , Isaacson Howard , Weiss Lauren M. , Brewer John M. , Hansen Brad M. S. , Hirsch Lea , Christiansen Jessie L. , Crepp Justin R. , Crossfield Ian J. M. , Schlieder Joshua E. , Ciardi David R. , Beichman Charles A. , Knutson Heather A. , Benneke Bjoern , Dressing Courtney D. , Livingston John H. , Deck Katherine M. , Lépine Sébastien , Rogers Leslie A. 
Published: January 2017

Abstract
We report precise radial velocity (RV) measurements of WASP-47, a G star that hosts three transiting planets in close proximity (a hot Jupiter, a super-Earth, and a Neptune-sized planet) and a non-transiting planet at 1.4 au. Through a joint analysis of previously published RVs and our own Keck-HIRES RVs, we significantly improve the planet mass and bulk density measurements. For the super-Earth WASP-47e (P = 0.79 days), we measure a mass of

M
⊕, and a bulk density of

g cm−3, consistent with a rocky composition. For the hot Jupiter WASP-47b (P = 4.2 days), we measure a mass of

M
⊕ (1.12 ± 0.04 M
Jup) and constrain its eccentricity to

at 3σ confidence. For the Neptune-size planet WASP-47d (P = 9.0 days), we measure a mass of

M
⊕ and a bulk density of

g cm−3, suggesting that it has a thick H/He envelope. For the outer non-transiting planet, we measure a minimum mass of

M
⊕ (1.29 ± 0.06 M
Jup), an orbital period of

days, and an orbital eccentricity of

. Our new measurements are consistent with but two to four times more precise than previous mass measurements.
THE KEPLER FOLLOW-UP OBSERVATION PROGRAM. I. A CATALOG OF COMPANIONS TO KEPLER STARS FROM HIGH-RESOLUTION IMAGING
Authors: Furlan E. , Ciardi D. R. , Everett M. E. , Saylors M. , Teske J. K. , Horch E. P. , Howell S. B. , van Belle G. T. , Hirsch L. A. , Gautier T. N. , Adams E. R. , Barrado D. , Cartier K. M. S. , Dressing C. D. , Dupree A. K. , Gilliland R. L. , Lillo-Box J. , Lucas P. W. , Wang J. 
Published: January 2017

Abstract
We present results from high-resolution, optical to near-IR imaging of host stars of Kepler Objects of Interest (KOIs), identified in the original Kepler field. Part of the data were obtained under the Kepler imaging follow-up observation program over six years (2009–2015). Almost 90% of stars that are hosts to planet candidates or confirmed planets were observed. We combine measurements of companions to KOI host stars from different bands to create a comprehensive catalog of projected separations, position angles, and magnitude differences for all detected companion stars (some of which may not be bound). Our compilation includes 2297 companions around 1903 primary stars. From high-resolution imaging, we find that ∼10% (∼30%) of the observed stars have at least one companion detected within 1″ (4″). The true fraction of systems with close (≲4″) companions is larger than the observed one due to the limited sensitivities of the imaging data. We derive correction factors for planet radii caused by the dilution of the transit depth: assuming that planets orbit the primary stars or the brightest companion stars, the average correction factors are 1.06 and 3.09, respectively. The true effect of transit dilution lies in between these two cases and varies with each system. Applying these factors to planet radii decreases the number of KOI planets with radii smaller than 2

by ∼2%–23% and thus affects planet occurrence rates. This effect will also be important for the yield of small planets from future transit missions such as TESS.
CHROMOSPHERE TO 1 au SIMULATION OF THE 2011 MARCH 7th EVENT: A COMPREHENSIVE STUDY OF CORONAL MASS EJECTION PROPAGATION
Authors: Jin M. , Manchester W. B. , Holst B. van der , Sokolov I. , Tóth G. , Vourlidas A. , Koning C. A. de , Gombosi T. I. 
Published: January 2017

ABSTRACT
We perform and analyze the results of a global magnetohydrodynamic simulation of the fast coronal mass ejection (CME) that occurred on 2011 March 7. The simulation is made using the newly developed Alfvén Wave Solar Model (AWSoM), which describes the background solar wind starting from the upper chromosphere and extends to 24 R
⊙. Coupling AWSoM to an inner heliosphere model with the Space Weather Modeling Framework extends the total domain beyond the orbit of Earth. Physical processes included in the model are multi-species thermodynamics, electron heat conduction (both collisional and collisionless formulations), optically thin radiative cooling, and Alfvén-wave turbulence that accelerates and heats the solar wind. The Alfvén-wave description is physically self-consistent, including non-Wentzel–Kramers–Brillouin reflection and physics-based apportioning of turbulent dissipative heating to both electrons and protons. Within this model, we initiate the CME by using the Gibson-Low analytical flux rope model and follow its evolution for days, in which time it propagates beyond STEREO A. A detailed comparison study is performed using remote as well as in situ observations. Although the flux rope structure is not compared directly due to lack of relevant ejecta observation at 1 au in this event, our results show that the new model can reproduce many of the observed features near the Sun (e.g., CME-driven extreme ultraviolet [EUV] waves, deflection of the flux rope from the coronal hole, “double-front” in the white light images) and in the heliosphere (e.g., shock propagation direction, shock properties at STEREO A).
A REVISED PLANETARY NEBULA LUMINOSITY FUNCTION DISTANCE TO NGC 628 USING MUSE
Authors: Kreckel K. , Groves B. , Bigiel F. , Blanc G. A. , Kruijssen J. M. D. , Hughes A. , Schruba A. , Schinnerer E. 
Published: January 2017

ABSTRACT
Distance uncertainties plague our understanding of the physical scales relevant to the physics of star formation in extragalactic studies. The planetary nebulae luminosity function (PNLF) is one of very few techniques that can provide distance estimates to within ∼10%; however, it requires a planetary nebula (PN) sample that is uncontaminated by other ionizing sources. We employ optical integral field unit spectroscopy using the Multi-Unit Spectroscopic Explorer on the Very Large Telescope to measure [O iii] line fluxes for sources unresolved on 50 pc scales within the central star-forming galaxy disk of NGC 628. We use diagnostic line ratios to identify 62 PNe, 30 supernova remnants, and 87 H ii regions within our fields. Using the 36 brightest PNe, we determine a new PNLF distance modulus of

29.91

−
0.13

+
0.08

mag (9.59

−
0.57

+
0.35

Mpc), which is in good agreement with literature values, but significantly larger than the previously reported PNLF distance. We are able to explain the discrepancy and recover the previous result when we reintroduce SNR contaminants to our sample. This demonstrates the power of full spectral information over narrowband imaging in isolating PNe. Given our limited spatial coverage within the Galaxy, we show that this technique can be used to refine distance estimates, even when IFU observations cover only a fraction of a galaxy disk.
CHROMOSPHERIC AND CORONAL ACTIVITY IN THE 500 MYR OLD OPEN CLUSTER M37: EVIDENCE FOR CORONAL STRIPPING?
Authors: Núñez Alejandro , Agüeros Marcel A. , Covey Kevin R. , López-Morales Mercedes 
Published: January 2017

ABSTRACT
We present the results of a spectroscopic survey to characterize chromospheric activity, as measured by

H
α

emission, in low-mass members of the 500 Myr old open cluster M37. Combining our new measurements of

H
α

luminosities (

L

H
α

) with previously cataloged stellar properties, we identify saturated and unsaturated regimes in the dependence of the

L

H
α

-to-bolometric luminosity ratio,

L

H
α

/

L

bol

, on the Rossby number R

o
. All rotators with R

o
smaller than 0.03 ± 0.01 converge to an activity level of

L

H
α

/

L

bol

=
(
1.27
±
0.02
)
×

10

−
4

. This saturation threshold (

R

o
,
sat

=
0.03
±
0.01

) is statistically smaller than that found in most studies of the rotation–activity relation. In the unsaturated regime, slower rotators have lower levels of chromospheric activity, with

L

H
α

/

L

bol

(R

o
) following a power-law of index

β
=
−
0.51
±
0.02

, slightly shallower than that found for a combined ≈650 Myr old sample of Hyades and Praesepe stars. By comparing this unsaturated behavior to that previously found for coronal activity in M37 (as measured via the X-ray luminosity,

L

X

), we confirm that chromospheric activity decays at a much slower rate than coronal activity with increasing R

o
. While a comparison of

L

H
α

and

L

X

for M37 members with measurements of both reveals a nearly 1:1 relation, removing the mass-dependencies by comparing instead

L

H
α

/

L

bol

and

L

X

/

L

bol

does not provide clear evidence for such a relation. Finally, we find that

R

o
,
sat

is smaller for our chromospheric than for our coronal indicator of activity (

R

o
,
sat

=
0.03
±
0.01

versus 0.09 ± 0.01). We interpret this as possible evidence for coronal stripping.
HST/COS OBSERVATIONS OF IONIZED GAS ACCRETION AT THE DISK–HALO INTERFACE OF M33
Authors: Zheng Y. , Peek J. E. G. , Werk J. K. , Putman M. E. 
Published: January 2017

ABSTRACT
We report the detection of accreting ionized gas at the disk–halo interface of the nearby galaxy M33. We analyze Hubble Space Telescope/Cosmic Origins Spectrograph absorption-line spectra of seven ultraviolet-bright stars evenly distributed across the disk of M33. We find Si iv absorption components consistently redshifted relative to the bulk M33's ISM absorption along all the sightlines. The Si iv detection indicates an enriched, disk-wide, ionized gas inflow toward the disk. This inflow is most likely multi-phase as the redshifted components can also be observed in ions with lower ionization states (e.g., S ii, P ii, Fe ii, Si ii). Kinematic modeling of the inflow is consistent with an accreting layer at the disk–halo interface of M33, which has an accretion velocity of

110

−
20

+
15

km

s

−
1

at a distance of

1.5

−
1.0

+
1.0

kpc above the disk. The modeling indicates a total mass of ∼3.9 × 107
M
⊙ for the accreting material at the disk–halo interface on the near side of the M33 disk, with an accretion rate of ∼2.9 M
⊙ yr−1. The high accretion rate and the level of metal enrichment suggest the inflow is likely to be the fallback of M33 gas from a galactic fountain and/or the gas pulled loosed during a close interaction between M31 and M33. Our study of M33 is the first to unambiguously reveal the existence of a disk-wide, ionized gas inflow beyond the Milky Way, providing a better understanding of gas accretion in the vicinity of a galaxy disk.
MAPPING THE POLARIZATION OF THE RADIO-LOUD Lyα NEBULA B3 J2330+3927*
Authors: You Chang , Zabludoff Ann , Smith Paul , Yang Yujin , Kim Eunchong , Jannuzi Buell , Prescott Moire K. M. , Matsuda Yuichi , Lee Myung Gyoon 
Published: January 2017

ABSTRACT
Lyα nebulae, or “Lyα blobs,” are extended (up to ∼100 kpc), bright (L
Lyα
≳ 1043 erg s−1) clouds of Lyα emitting gas that tend to lie in overdense regions at z ∼ 2–5. The origin of the Lyα emission remains unknown, but recent theoretical work suggests that measuring the polarization might discriminate among powering mechanisms. Here we present the first narrowband imaging polarimetry of a radio-loud Lyα nebula, B3 J2330+3927, at z = 3.09, with an embedded active galactic nucleus (AGN). The AGN lies near the blob’s Lyα emission peak, and its radio lobes align roughly with the blob’s major axis. With the SPOL polarimeter on the 6.5 m MMT telescope, we map the total (Lyα + continuum) polarization in a grid of circular apertures of a radius of 0.″6 (4.4 kpc), detecting a significant (>2σ) polarization fraction P
% in nine apertures and achieving strong upper limits (as low as 2%) elsewhere. P
% increases from <2% at ∼5 kpc from the blob center to 17% at ∼15–25 kpc. The detections are distributed asymmetrically, roughly along the nebula’s major axis. The polarization angles θ are mostly perpendicular to this axis. Comparing the Lyα flux to that of the continuum and conservatively assuming that the continuum is highly polarized (20%–100%) and aligned with the total polarization, we place lower limits on the polarization of the Lyα emission P
%,Lyα
ranging from no significant polarization at ∼5 kpc from the blob center to 3%–17% at 10–25 kpc. Like the total polarization, the Lyα polarization detections occur more often along the blob’s major axis.
AN INTEGRAL CONDITION FOR CORE-COLLAPSE SUPERNOVA EXPLOSIONS
Authors: Murphy Jeremiah W. , Dolence Joshua C. 
Published: January 2017

ABSTRACT
We derive an integral condition for core-collapse supernova (CCSN) explosions and use it to construct a new diagnostic of explodability. The fundamental challenge in CCSN theory is to explain how a stalled accretion shock revives to explode a star. In this manuscript, we assume that the shock revival is initiated by the delayed-neutrino mechanism and derive an integral condition for spherically symmetric shock expansion, v

s
> 0. One of the most useful one-dimensional explosion conditions is the neutrino luminosity and mass-accretion rate (

L

ν

–



˙

) critical curve. Below this curve, steady-state stalled solutions exist, but above this curve, there are no stalled solutions. Burrows & Goshy suggested that the solutions above this curve are dynamic and explosive. In this manuscript, we take one step closer to proving this supposition; we show that all steady solutions above this curve have v

s
> 0. Assuming that these steady v

s
> 0 solutions correspond to explosion, we present a new dimensionless integral condition for explosion, Ψ > 0. Ψ roughly describes the balance between pressure and gravity, and we show that this parameter is equivalent to the τ condition used to infer the

L

ν

–



˙

critical curve. The illuminating difference is that there is a direct relationship between Ψ and v

s
. Below the critical curve, Ψ may be negative, positive, and zero, which corresponds to receding, expanding, and stalled-shock solutions. At the critical curve, the minimum Ψ solution is zero; above the critical curve, Ψmin > 0, and all steady solutions have v

s
> 0. Using one-dimensional simulations, we confirm our primary assumptions and verify that Ψmin > 0 is a reliable and accurate explosion diagnostic.
SPITZER OBSERVATIONS CONFIRM AND RESCUE THE HABITABLE-ZONE SUPER-EARTH K2-18b FOR FUTURE CHARACTERIZATION
Authors: Benneke Björn , Werner Michael , Petigura Erik , Knutson Heather , Dressing Courtney , Crossfield Ian J. M. , Schlieder Joshua E. , Livingston John , Beichman Charles , Christiansen Jessie , Krick Jessica , Gorjian Varoujan , Howard Andrew W. , Sinukoff Evan , Ciardi David R. , Akeson Rachel L. 
Published: January 2017

ABSTRACT
The recent detections of two transit events attributed to the super-Earth candidate K2-18b have provided the unprecedented prospect of spectroscopically studying a habitable-zone planet outside the solar system. Orbiting a nearby M2.5 dwarf and receiving virtually the same stellar insolation as Earth, K2-18b would be a prime candidate for the first detailed atmospheric characterization of a habitable-zone exoplanet using the Hubble Space Telescope (HST)and James Webb Space Telescope (JWST). Here, we report the detection of a third transit of K2-18b near the predicted transit time using the Spitzer Space Telescope. The Spitzer detection demonstrates the periodic nature of the two transit events discovered by K2, confirming that K2-18 is indeed orbited by a super-Earth in a 33 day orbit, ruling out the alternative scenario of two similarly sized, long-period planets transiting only once within the 75 day Kepler Space Telescope (K2) observation. We also find, however, that the transit event detected by Spitzer occurred 1.85 hr (

7
σ

) before the predicted transit time. Our joint analysis of the Spitzer and K2 photometry reveals that this early occurrence of the transit is not caused by transit timing variations, but the result of an inaccurate ephemeris due to a previously undetected data anomaly in the K2 photometry. We refit the ephemeris and find that K2-18b would have been lost for future atmospheric characterizations with HST and JWST if we had not secured its ephemeris shortly after the discovery. We caution that immediate follow-up observations as presented here will also be critical for confirming and securing future planets discovered by the Transiting Exoplanet Survey Satellite (TESS), in particular if only two transit events are covered by the relatively short 27-day TESS campaigns.
An International Comparison of the Construction of the "Educational Research Quality/ Indicator Scheme"
Authors: Yang Shen-Keng 
Published: January 2017

The proposed presentation will investigate deeply into the construction of ”Educational Research Quality/ Indicator Scheme” in EU, OECD and in the USA, the UK, France, Germany, and Australia . Based on the results of one of the sub-projects of Integrated Joint Research Project financed by Science Council in Taiwan , this paper will focus on the process and construction of an “educational research quality standard/indicator scheme” through international comparison. The implications of the results of comparison for improving education research generally will be carefully examined with a view to developing a suitable "Educational Research Quality Standard/Indicator Scheme" for future use in assessing the input and output of research projects funded by governmental or non-governmental agencies.
EFFECT OF PROTEIN ADDITION ON PROPERTIES OF GUAYULE NATURAL RUBBER
Authors: Lhamo Dhondup , McMahan Colleen 
Published: January 2017

ABSTRACTParthenium argentatum, commonly known as guayule, is a desert shrub cultivated as a domestic source of natural rubber in the semi-arid southwestern United States. Guayule natural rubber (GR) may be used to replace petroleum-based rubber or in place of Hevea natural rubber (NR), but substitution must take into consideration differences in physical and chemical properties. Currently, Hevea NR is required in tire applications, especially aircraft and truck tires, because of its high oxidative resistance, rapid cure rate, and exceptional stress–strain response. These outstanding features are attributed to the presence of nonrubber constituents, mainly proteins and lipids, which cause the rubber to gel, and they contribute to strain-induced crystallization. In contrast, GR is low in proteins and is thus deprived of some attributes of Hevea. Addition of amino acids and proteins to guayule could potentially improve performance and thereby widen the range of applications for use. In a previous study, amino acids blended with GR latex improved thermo-oxidative stability, served as plasticizers and cure accelerators, and enhanced green strength slightly, but tensile strength was not improved. Here, a series of bio-based commercial proteins (gelatin, soy, albumin, casein, zein, gliadin, and gluten) were added to GR as a latex blend. In general, protein addition reduced bulk viscosity and improved thermo-oxidative stability. The gel content and green strength of the polymer–protein blends were increased, with the exception of gliadin, but not to levels observed for Hevea. Effects on vulcanization and mechanical properties in compounds were surprisingly influenced by the choice of antioxidants used. Our results demonstrate the potential of proteins as bio-based rubber compounding additives.