bluuebunny/crossref_metadata_2025_split huggingface dataset:
CLASSIFICATION OF SATELLITE RESONANCES IN THE SOLAR SYSTEM
Authors: Luan Jing , Goldreich Peter 
Published: December 2016

ABSTRACT
Several pairs of solar system satellites occupy mean motion resonances (MMRs). We divide these into two groups according to their proximity to exact resonance. Proximity is measured by the existence of a separatrix in phase space. MMRs between Io–Europa, Europa–Ganymede, and Enceladus–Dione are too distant from exact resonance for a separatrix to appear. A separatrix is present only in the phase spaces of the Mimas–Tethys and Titan–Hyperion MMRs, and their resonant arguments are the only ones to exhibit substantial librations. Could there be a causal connection between the libration amplitude and the presence of a separatrix? Our suspicions were aroused by Goldreich & Schlichting, who demonstrate that sufficiently deep in a MMR, eccentricity damping could destabilize librations. However, our investigation reveals that libration amplitudes in both the Mimas–Tethys and Titan–Hyperion MMRs are fossils. Although the Mimas–Tethys MMR is overstable, its libration amplitude grows on the tidal damping timescale of Mimas’s inclination, which is considerably longer than a Hubble time. On the other hand, the Titan–Hyperion MMR is stable, but tidal damping of Hyperion’s eccentricity is too weak to have affected the amplitude of its libration.
SPECKLE INTERFEROMETRY AT THE U.S. NAVAL OBSERVATORY. XXI.
Authors: Mason Brian D. , Hartkopf William I. , Bredthauer Greg , Ferguson Eric W. , Finch Charlie T. , Kilian Christopher M. , Rafferty Theodore J. , Ragan Tai J. , Wieder Gary D. 
Published: December 2016

ABSTRACT
The results of 2408 intensified CCD observations of double stars, made with the 26 inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1602 mean relative positions and range in separation from 1.″94 to 107.″41, with a median separation of 11.″96. This is the twenty-first in this series of papers and covers the period from 2015 January 13 through 2015 December 19. Significant instrumentation changes are reported in this paper.
DELAY SPECTRUM WITH PHASE-TRACKING ARRAYS: EXTRACTING THE H i POWER SPECTRUM FROM THE EPOCH OF REIONIZATION
Authors: Paul Sourabh , Sethi Shiv K. , Morales Miguel F. , Dwarkanath K. S. , Shankar N. Udaya , Subrahmanyan Ravi , Barry N. , Beardsley A. P. , Bowman Judd D. , Briggs F. , Carroll P. , de Oliveira-Costa A. , Dillon Joshua S. , Ewall-Wice A. , Feng L. , Greenhill L. J. , Gaensler B. M. , Hazelton B. J. , Hewitt J. N. , Hurley-Walker N. , Jacobs D. J. , Kim Han-Seek , Kittiwisit P. , Lenc E. , Line J. , Loeb A. , McKinley B. , Mitchell D. A. , Neben A. R. , Offringa A. R. , Pindor B. , Pober J. C. , Procopio P. , Riding J. , Sullivan I. S. , Tegmark M. , Thyagarajan Nithyanandan , Tingay S. J. , Trott C. M. , Wayth R. B. , Webster R. L. , Wyithe J. S. B. , Cappallo Roger , Johnston-Hollitt M. , Kaplan D. L. , Lonsdale C. J. , McWhirter S. R. , Morgan E. , Oberoi D. , Ord S. M. , Prabu T. , Srivani K. S. , Williams A. , Williams C. L. 
Published: December 2016

ABSTRACT
The detection of redshifted 21 cm emission from the epoch of reionization (EoR) is a challenging task owing to strong foregrounds that dominate the signal. In this paper, we propose a general method, based on the delay spectrum approach, to extract H i power spectra that are applicable to tracking observations using an imaging radio interferometer ("Delay Spectrum with Imaging Arrays"). Our method is based on modeling the H i signal taking into account the impact of wide field effects such as the w-term, which are then used as appropriate weights in cross-correlating the measured visibilities. Our method is applicable to any radio interferometer that tracks a phase center and could be utilized for arrays such as the Murchison Widefield Array (MWA), Low Frequency Array (LOFAR), Giant Meterwave Radio Telescope (GMRT), Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER), and HERA. In the literature the delay spectrum approach has been implemented for near-redundant baselines using drift scan observations. In this paper we explore the scheme for non-redundant tracking arrays. This is the first application of delay spectrum methodology to such data to extract the H i signal. We analyze 3 hr of MWA tracking data on the EoR1 field. We present both two-dimensional (

) and one-dimensional (k) power spectra from the analysis. Our results are in agreement with the findings of other pipelines developed to analyze the MWA EoR data.
ROTATIONAL EVOLUTION OF MAGNETARS IN THE PRESENCE OF A FALLBACK DISK
Authors: Tong H. , Wang W. , Liu X. W. , Xu R. X. 
Published: December 2016

ABSTRACT
Magnetars may have a strong surface dipole field. Observationally, two magnetars may have passive fallback disks. In the presence of a fallback disk, the rotational evolution of magnetars may be changed. In the self-similar fallback disk model, it is found that (1) when the disk mass is significantly lower than 10−6 M
⊙, the magnetar is unaffected by the fallback disk and it will be a normal magnetar. (2) When the disk mass is high but the surface dipole field of the magnetar is about or below 1014 G, the magnetar will also be a normal magnetar. A magnetar plus a passive fallback disk system is expected. This may correspond to the observations of magnetars 4U 0142+61 and 1E 2259+586. (3) When the disk mass is high and the surface dipole field of the magnetar is as high as 4 × 1015 G, the magnetar will evolve from the ejector phase to the propeller phase, and then enter rotational equilibrium. The magnetar will be slowed down quickly in the propeller phase. The final rotational period can be as high 2 × 104 s. This may correspond to the super-slow magnetar in the supernova remnant RCW 103. Therefore, the three types of magnetars can be understood in a unified way.
A PHYSICALLY BASED MODEL OF THE IONIZING RADIATION FROM ACTIVE GALAXIES FOR PHOTOIONIZATION MODELING
Authors: Thomas A. D. , Groves B. A. , Sutherland R. S. , Dopita M. A. , Kewley L. J. , Jin C. 
Published: December 2016

ABSTRACT
We present a simplified model of active galactic nucleus (AGN) continuum emission designed for photoionization modeling. The new model oxaf reproduces the diversity of spectral shapes that arise in physically based models. We identify and explain degeneracies in the effects of AGN parameters on model spectral shapes, with a focus on the complete degeneracy between the black hole mass and AGN luminosity. Our reparametrized model oxaf removes these degeneracies and accepts three parameters that directly describe the output spectral shape: the energy of the peak of the accretion disk emission

, the photon power-law index of the non-thermal emission Γ, and the proportion of the total flux that is emitted in the non-thermal component

. The parameter

is presented as a function of the black hole mass, AGN luminosity, and “coronal radius” of the optxagnf model upon which oxaf is based. We show that the soft X-ray excess does not significantly affect photoionization modeling predictions of strong emission lines in Seyfert narrow-line regions. Despite its simplicity, oxaf accounts for opacity effects where the accretion disk is ionized because it inherits the “color correction” of optxagnf. We use a grid of mappings photoionization models with oxaf ionizing spectra to demonstrate how predicted emission-line ratios on standard optical diagnostic diagrams are sensitive to each of the three oxaf parameters. The oxaf code is publicly available in the Astrophysics Source Code Library.
SEARCH FOR DIFFERENCES BETWEEN RADIO-LOUD AND RADIO-QUIET GAMMA-RAY PULSAR POPULATIONS WITH FERMI-LAT DATA
Authors: Sokolova E. V. , Rubtsov G. I. 
Published: December 2016

ABSTRACT
Observations by the Fermi-Large Area Telescope (LAT) have enabled us to explore the population of non-recycled gamma-ray pulsars with a set of 112 objects. It was recently noted that there are apparent differences in the properties of radio-quiet and radio-loud subsets. In particular, the average observed radio-loud pulsar is younger than the average radio-quiet one and is located at lower Galactic latitude. Even so, the analysis based on the full list of pulsars may suffer from selection effects. Namely, most radio-loud pulsars are first discovered in the radio band, while radio-quiet ones are found using the gamma-ray data. In this work we perform a blind search for gamma-ray pulsars using the Fermi-LAT data alone, using all point sources from the 3FGL catalog as the candidates. Unlike our previous work, the present catalog is constructed with a semi-coherent method based on the time-differencing technique and covers the full range of characteristic ages down to 1 kyr. The search resulted in a catalog of 40 non-recycled pulsars, 25 of which are radio-quiet. All pulsars found in the search were previously known gamma-ray pulsars. We find no statistically significant differences in age or in distributions in Galactic latitude for the radio-loud and radio-quiet pulsars, while the distributions in rotation period are marginally different with a statistical probability of

. The fraction of radio-quiet pulsars is estimated as

. The results are in agreement with the predictions of the outer magnetosphere models, while the polar cap models are disfavored.
QUANTIFYING THE INTERSTELLAR MEDIUM AND COSMIC RAYS IN THE MBM 53, 54, AND 55 MOLECULAR CLOUDS AND THE PEGASUS LOOP USING FERMI-LAT GAMMA-RAY OBSERVATIONS
Authors: Mizuno T. , Abdollahi S. , Fukui Y. , Hayashi K. , Okumura A. , Tajima H. , Yamamoto H. 
Published: December 2016

ABSTRACT
A study of the interstellar medium (ISM) and cosmic rays (CRs) using Fermi Large Area Telescope (LAT) data, in a region encompassing the nearby molecular clouds MBM 53, 54, and 55 and a far-infrared loop-like structure in Pegasus, is reported. By comparing the Planck dust thermal emission model with Fermi-LAT γ-ray data, it was found that neither the dust radiance (R) nor the dust opacity at 353 GHz (τ
353) was proportional to the total gas column density N(Htot) primarily because N(Htot)/R and N(Htot)/τ
353 depend on the dust temperature (T
d). The N(Htot) distribution was evaluated using γ-ray data by assuming the regions of high T
d to be dominated by optically thin atomic hydrogen (

) and by employing an empirical linear relation of N(Htot)/R to T
d. It was determined that the mass of the gas not traced by the 21 cm or 2.6 mm surveys is ∼25% of the mass of

in the optically thin case and is larger than the mass of the molecular gas traced by carbon monoxide by a factor of up to 5. The measured γ-ray emissivity spectrum is consistent with a model based on CR spectra measured at the Earth and a nuclear enhancement factor of ≤1.5. It is, however, lower than local

emissivities reported by previous Fermi-LAT studies employing different analysis methods and assumptions on ISM properties by 15%–20% in energies below a few GeV, even if we take account of the statistical and systematic uncertainties. The origin of the discrepancy is also discussed.
HIGH ENERGY NEUTRINOS PRODUCED IN THE ACCRETION DISKS BY NEUTRONS FROM NUCLEI DISINTEGRATED IN THE AGN JETS
Authors: Bednarek W. 
Published: December 2016

ABSTRACT
We investigate the consequences of acceleration of nuclei in jets of active galaxies not far from the surface of an accretion disk. The nuclei can be accelerated in the re-connection regions in the jet and/or at the jet boundary, between the relativistic jet and its cocoon. It is shown that the relativistic nuclei can efficiently fragment onto specific nucleons in collisions with the disk radiation. Neutrons, directed toward the accretion disk, take a significant part of energy from the relativistic nuclei. These neutrons develop a cascade in the dense accretion disk. We calculate the neutrino spectra produced in such a hadronic cascade within the accretion disk. We propose that the neutrinos produced in such a scenario, from the whole population of super-massive black holes in active galaxies, can explain the extragalactic neutrino background recently measured by the IceCube neutrino detector, provided that a 5% fraction of galaxies have an active galactic nucleus and a few percent of neutrons reach the accretion disk. We predict that the neutrino signals in the present neutrino detectors, produced in terms of such a model, will not be detectable even from the nearby radio galaxies similar to M87.
THE COSMIC EVOLUTION OF THE METALLICITY DISTRIBUTION OF IONIZED GAS TRACED BY LYMAN LIMIT SYSTEMS
Authors: Lehner Nicolas , O’Meara John M. , Howk J. Christopher , Prochaska J. Xavier , Fumagalli Michele 
Published: December 2016

ABSTRACT
We present the first results from our KODIAQ Z survey aimed at determining the metallicity distribution and physical properties of the

partial and full Lyman limit systems (pLLSs and LLSs;

), which are probed of the interface regions between the intergalactic medium (IGM) and galaxies. We study 31 H i-selected pLLSs and LLSs at

observed with Keck/HIRES in absorption against background QSOs. We compare the column densities of metal ions to H i and use photoionization models to assess the metallicity. The metallicity distribution of the pLLSs/LLSs at

is consistent with a unimodal distribution peaking at

. The metallicity distribution of these absorbers therefore evolves markedly with z since at

it is bimodal with peaks at

and −0.3. There is a substantial fraction (25%–41%) of pLLSs/LLSs with metallicities well below those of damped Lyα absorbers (DLAs) at any studied z from

to

–4, implying reservoirs of metal-poor, cool, dense gas in the IGM/galaxy interface at all z. However, the gas probed by pLLSs and LLSs is rarely pristine, with a fraction of 3%–18% for pLLSs/LLSs with

. We find C/α enhancement in several pLLSs and LLSs in the metallicity range

, where C/α is 2–5 times larger than observed in Galactic metal-poor stars or high-redshift DLAs at similar metallicities. This is likely caused by preferential ejection of carbon from metal-poor galaxies into their surroundings.
A PROFILE ANALYSIS OF RAMAN-SCATTERED O VI BANDS AT 6825 Å AND 7082 Å IN SANDULEAK’S STAR
Authors: Heo Jeong-Eun , Angeloni Rodolfo , Mille Francesco Di , Palma Tali , Lee Hee-Won 
Published: December 2016

ABSTRACT
We present a detailed modeling of the two broad bands observed at 6825 and 7082 Å in Sanduleak’s star, a controversial object in the Large Magellanic Cloud. These bands are known to originate from Raman scattering of O vi λ
λ 1032 and 1038 photons with atomic hydrogen and are only observed in bona fide symbiotic stars. Our high-resolution spectrum obtained with the Magellan Inamori Kyocera Echelle spectrograph at the Magellan-Clay Telescope reveals, quite surprisingly, that the profiles of the two bands look very different: while the Raman 6825 Å band shows a single broad profile with a redward extended bump, the Raman 7082 Å band exhibits a distinct triple-peak profile. Our model suggests that the O vi emission nebula can be decomposed into a red, blue, and central emission region from an accretion disk, a bipolar outflow, and a further compact, optically thick region. We also perform Monte Carlo simulations with the aim of fitting the observed flux ratio F(6825)/F(7082) ∼ 4.5, which indicates that the neutral region in Sanduleak’s star is characterized by the column density N
H i
∼ 1 × 1023 cm−2.
MEASUREMENT OF A REDSHIFT-SPACE POWER SPECTRUM FOR BOSS GALAXIES AND THE GROWTH RATE AT REDSHIFT 0.57
Authors: Li Zhigang , Jing Y. P. , Zhang Pengjie , Cheng Dalong 
Published: December 2016

ABSTRACT
We present a measurement of the two-dimensional (2D) redshift-space power spectrum for the Baryon Oscillation Spectroscopic Survey Data Release 11 CMASS galaxies in the northern Galactic cap based on the method developed by Jing & Börner. In this method, we first measure the 2D redshift-space correlation function and obtain the 2D power spectrum based on Fourier transform of the correlation function. The method is tested with an N-body mock galaxy catalog, which demonstrates that the method can yield an accurate and unbiased measurement of the redshift-space power spectrum given that the input 2D correlation function is correct. Compared with previous measurements in literature that are usually based on direct Fourier transform in redshift space, our method has the advantages that the window function and shot noise are fully corrected. Thus, our measurement can facilitate a direct comparison with the theoretical predictions. Our 2D power spectrum, by construction, can reproduce the 2D correlation function, and it can reproduce, for example, the 2D power spectrum of Beutler et al. accurately if ours is convolved with the window function they provided. We then develop a method to measure the structure growth rate, by separating the anisotropic redshift-space power spectrum from the isotropic real-space power spectrum. We have carefully corrected for the nonlinearities in the mapping from real space to redshift space, according to the theoretical model of Zhang et al. Finally, we obtain the measurement of structure growth rate f(

)σ
8(

) = 0.438 ± 0.037 at the effective redshift

= 0.57. The result is useful for constraining cosmological parameters. The measurements of the 2D power spectrum will be released soon.
EXTENSION OF THE MURAM RADIATIVE MHD CODE FOR CORONAL SIMULATIONS
Authors: Rempel M. 
Published: December 2016

ABSTRACT
We present a new version of the MURaM radiative magnetohydrodynamics (MHD) code that allows for simulations spanning from the upper convection zone into the solar corona. We implement the relevant coronal physics in terms of optically thin radiative loss, field aligned heat conduction, and an equilibrium ionization equation of state. We artificially limit the coronal Alfvén and heat conduction speeds to computationally manageable values using an approximation to semi-relativistic MHD with an artificially reduced speed of light (Boris correction). We present example solutions ranging from quiet to active Sun in order to verify the validity of our approach. We quantify the role of numerical diffusivity for the effective coronal heating. We find that the (numerical) magnetic Prandtl number determines the ratio of resistive to viscous heating and that owing to the very large magnetic Prandtl number of the solar corona, heating is expected to happen predominantly through viscous dissipation. We find that reasonable solutions can be obtained with values of the reduced speed of light just marginally larger than the maximum sound speed. Overall this leads to a fully explicit code that can compute the time evolution of the solar corona in response to photospheric driving using numerical time steps not much smaller than 0.1 s. Numerical simulations of the coronal response to flux emergence covering a time span of a few days are well within reach using this approach.
THE SPATIALLY RESOLVED
COOLING LINE DEFICIT IN GALAXIES
Authors: Smith J. D. T. , Croxall Kevin , Draine Bruce , Looze Ilse De , Sandstrom Karin , Armus Lee , Beirão Pedro , Bolatto Alberto , Boquien Mederic , Brandl Bernhard , Crocker Alison , Dale Daniel A. , Galametz Maud , Groves Brent , Helou George , Herrera-Camus Rodrigo , Hunt Leslie , Kennicutt Robert , Walter Fabian , Wolfire Mark 
Published: December 2016

ABSTRACT
We present [C ii] 158 μm measurements from over 15,000 resolved regions within 54 nearby galaxies of the Kingfish program to investigate the so-called [C ii] “line-cooling deficit” long known to occur in galaxies with different luminosities. The [C ii]/TIR ratio ranges from above 1% to below 0.1% in the sample, with a mean value of 0.48 ± 0.21%. We find that the surface density of 24 μm emission dominates this trend, with [C ii]/TIR dropping as

increases. Deviations from this overall decline are correlated with changes in the gas-phase metal abundance, with higher metallicity associated with deeper deficits at a fixed surface brightness. We supplement the local sample with resolved [C ii] measurements from nearby luminous infrared galaxies and high-redshift sources from z = 1.8–6.4, and find that star formation rate density drives a continuous trend of deepening [C ii] deficit across six orders of magnitude in

. The tightness of this correlation suggests that an approximate

can be estimated directly from global measurements of [C ii]/TIR, and a relation is provided to do so. Several low-luminosity active galactic nucleus (AGN) hosts in the sample show additional and significant central suppression of [C ii]/TIR, but these deficit enhancements occur not in those AGNs with the highest X-ray luminosities, but instead those with the highest central starlight intensities. Taken together, these results demonstrate that the [C ii] line-cooling line deficit in galaxies likely arises from local physical phenomena in interstellar gas.
Politique de gestion de la diversité dans les grandes écoles françaises : quelles intentions stratégiques ?
Authors: Redon Gaëlle 
Published: December 2016

Cet article se centre sur les politiques de gestion de la diversité des Grandes Écoles françaises. La plupart des recherches sur le management de la diversité se concentrent globalement sur les entreprises en montrant comment le management de la diversité identifie de nouveaux viviers de recrutement permettant une plus grande créativité des salariés et une performance économique accrue et de faire face au risque juridique, compte tenu des nombreuses lois sur la lutte contre les discriminations. Quelques recherches se penchent sur les Grandes Écoles, mais jusqu’à présent, pour présenter les actions de diversité centrées sur les étudiants. En parlant des intentions stratégiques des Grandes Écoles, nous déplaçons le centre d’intérêt. Au travers des résultats issus d’une méthodologie qualitative reposant sur une observation participante et d’une enquête réalisée sur le terrain avec une base d’entretiens semi-directifs, nous tenterons de répondre à la problématique suivante : Le management de la diversité dans les Grandes Écoles est-il la nouvelle voie pour répondre aux contraintes sociales, légales et économiques et les transformer en performances ? Autrement dit, quelles sont les causes, les impacts et les limites de l’ouverture des Grandes Écoles à la diversité ? L’apport principal de cet article est donc de comprendre que la diversité des individus et de leurs parcours est un enjeu social, légal, économique et stratégique de plus en plus en prégnant dans les Grandes Écoles. Néanmoins, cette prise en compte connaît des limites. Elle doit en effet faire face à des contraintes fortes qui requièrent un management adapté que toutes les Grandes Écoles ne sont pas prêtes à mettre en place. Dans cette recherche, seront ainsi étudiés les enjeux d’un pilotage efficace et ses impacts escomptés sur la performance qualitative (dynamisme, motivation, investissement, image...) et quantitative (augmentation de la rentabilité) de ce type d’organisations. Nos conclusions amènent finalement à nous interroger sur les causes, les impacts et les limites de l’ouverture des Grandes Écoles à la diversité.
L'organisation de Bank Al-Maghrib de 1959 à nos jours : l'émergence de la banque centrale au Maroc
Authors: Feiertag Olivier 
Published: December 2016

L'histoire de Bank Al-Maghrib, la banque centrale du Maroc, constitue un cas d'école pour étudier les évolutions de l'organisation et de la gouvernance d'une banque centrale. Fondée en 1959, à partir de l'ancienne Banque d'État du Maroc qui datait du protectorat français, Bank Al-Maghrib présente les trois modèles du central banking qui se sont succédé des années 1960 à nos jours : banque d'émission nationale, elle met son organisation au service du financement de l'économie marocaine en pleine croissance ; la crise de la dette et le plan d'ajustement structurel négocié avec le FMI dans les années 1980 et 1990 font évoluer ce modèle dans le sens d'une banque centrale indépendante qui débouche dans les années 2000 sur une révolution managériale inséparable de l'émergence de l'économie et de la société marocaine.