bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some results on the radio‐SZ correlation for galaxy cluster radio halos
Authors: Basu K. 
Published: October 2014

AbstractWe present correlation results for the radio halo power in galaxy clusters with the integrated thermal Sunyaev‐Zel'dovich (SZ) effect signal, including new results obtained at sub‐GHz frequencies. The radio data is compiled from several published works, and the SZ measurements are taken from the Planck ESZ cluster catalog. The tight correlation between the radio halo power and the SZ effect demonstrates a clear correspondence between the thermal and non‐thermal electron populations in the intra‐cluster medium, as already have been shown in X‐ray based studies. The radio power varies roughly as the square of the global SZ signal, but when the SZ signal is scaled to within the radio halo radius the correlation becomes approximately linear, with reduced intrinsic scatter. We do not find any strong indication of a bi‐modal division in the radio halo cluster population, as has been reported in the literature, which suggests that such duality could be an artifact of X‐ray selection. We compare the YSZ dependence of radio halos with simplified predictions from theoretical models, and discuss some implications and shortcomings of the present work. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fundamental parameters of FR II radio galaxies and their impact on groups and clusters' environments
Authors: Kapińska A.D. , Uttley P. 
Published: October 2014

AbstractRadio galaxies are among the largest and most powerful single objects known and are found at variety of redshifts, hence they are believed to have had a significant impact on the evolving Universe. Their relativistic jets inject considerable amounts of energy into the environments in which the sources reside; thus the knowledge of the fundamental properties (such as kinetic luminosities, lifetimes and ambient gas densities) of these sources is crucial for understanding AGN feedback in galaxy clusters. In this work, we explore the intrinsic and extrinsic fundamental properties of Fanaroff‐Riley II (FR II) objects through the construction of multidimensional Monte Carlo simulations which use complete, flux limited radio catalogues and semi‐analytical models of FR IIs' time evolution to create artificial samples of radio galaxies. This method allows us to set better limits on the confidence intervals of the intrinsic and extrinsic fundamental parameters and to investigate the total energy produced and injected to the clusters' environments by populations of FR IIs at various cosmological epochs (0.0 < z < 2.0). We find the latter estimates to be strikingly robust despite the strong degeneracy between the fundamental parameters – such a result points to a conclusive indicator of the scale of AGN feedback in clusters of galaxies. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The evolution of the Y –M scaling relation in MUSIC clusters
Authors: Sembolini F. , Yepes G. , De Petris M. , Gottlöber S. , Lamagna L. , Comis B. 
Published: October 2014

AbstractThis work describes the baryon content and Sunyaev‐Zeldovich properties of the MUSIC (Marenostrum‐MultiDark SIm‐ulations of galaxy clusters) dataset and their evolution with redshift and aperture radius. The MUSIC dataset is one of the largest samples of hydrodynamically simulated galaxy clusters (more than 2000 objects, including more than 500 clusters). We show that when the effects of cooling and stellar feedbacks are properly taken into account, the gas fraction of the MUSIC clusters consistently agrees with recent observational results. Moreover, the gas fraction has a net dependence with the total mass of the cluster and increases slightly with redshift at high overdensities.The study of the Y –M relation confirms the consistence of the self‐similar model, showing no evolution with redshift at low overdensities. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Observability of YSOs with the WISE and AKARI infrared space observatories
Authors: Zahorecz S. , Töth L.V. , Marton G. , Ueno M. , Tamura M. , Kawamura A. , Kitamura Y. 
Published: October 2014

AbstractLarge area surveys allow us to identify young stellar objects and classify them based on their colours. The near‐, mid‐ and far‐infrared filters' sensitivities are different, therefore different proportions of young stars are observable. Evolutionary times for the different classes can be concluded from the popularity of the classes. Our aim was to investigate the completeness of the YSO detections. With the use of only mid‐ or only far‐infrared surveys, we will miss one part of the young stellar objects. Without far‐infrared data one third of the Class 0–II objects can remain invisible. Class III sources are almost invisible above 65 μm. For a comprehensive study we have to use the available data in the whole infrared range. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A statistical dynamical study of meteorite impactors: A case study based on parameters derived from the Bosumtwi impact event
Authors: Galiazzo M.A. , Bazsó Á. , Huber M.S. , Losiak A. , Dvorak R. , Koeberl C. 
Published: October 2014

AbstractThe study of meteorite craters on Earth provides information about the dynamic evolution of bodies within the Solar System. the Bosumtwi crater is a well studied, 10.5 km in diameter, ca. 1.07 Myr old impact structure located in Ghana. The impactor was ∼1 km in diameter, an ordinary chondrite and struck the Earth with an angle between 30° and 45° from the horizontal. We have used a two phase backward integration to constrain the most probable parent region of the impactor. We find that the most likely source region is a high inclination object from the Middle Main Belt. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exploring the North‐South asymmetry in a Babcock‐Leighton dynamo
Authors: Belucz B. , Forgács‐Dajka E. , Dikpati M. 
Published: October 2014

AbstractWe present here a Babcock‐Leighton, kinematic flux‐transport solar dynamo model, based on an earlier model (Dikpati & Charbonneau 1999), operating in a full spherical shell of the convection zone, to investigate the properties of NorthSouth (N‐S) asymmetry. We develop a C language code for this model in order to examine the N‐S asymmetry. The main components of the model are a solar‐like internal differential rotation profile, a depth‐dependent diffusivity, and a Babcock‐Leighton type poloidal source. Our purpose here is to study what kind of North‐South asymmetry is produced in solar cycle patterns when the Babcock‐Leighton poloidal source is asymmetric between North and South. We present our solutions in the form of model butterfly diagrams in which we plot the tachocline toroidal field and surface radial field, and compare them with observations. We find that the dynamos in the northern and southern hemispheres operate nearly independently – if the Babcock‐Leighton source is much smaller in the southern hemisphere with respect to that in the northern hemisphere, the dynamo in the southern hemisphere gets weaker and weaker, but the dynamo in the northern hemisphere runs without being affected by the dynamo in the southern hemisphere. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Doppler imaging of the double‐lined active binary V824 Ara
Authors: Kriskovics L. , Vida K. , Kővári Zs. , Garcia‐Alvarez D. , Oláh K. 
Published: October 2014

AbstractWe introduce an iterative spectral disentangling technique combined with Doppler imaging in order to recover surface temperature maps for both components of double‐lined active binary systems. Our method provides an opportunity to separate spectra of the active components while minimizing the unwanted disturbances on the given line profile from the other component. The efficiency of the method is demonstrated on real data of the double‐lined RS CVn‐type binary V824 Ara. The resulting Doppler images reveal cool spots on the polar regions as well as low‐latitude features on both of the stars. Moreover, both components have hot spots, that are facing each other. This may indicate interconnection between the stellar magnetic fields. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of the possible Blazhko‐effect Cepheid V473 Lyrae
Authors: Molnár L. , Szabados L. , Dukes R. J. , Győrffy Á. , Szabó R. 
Published: October 2014

AbstractV473 Lyrae is a peculiar Galactic Cepheid, showing strong amplitude modulation that resembles the Blazhko‐effect observed in RR Lyrae stars. We collected data spanning several modulation cycles and started a detailed analysis. The first results indicate that the star shows both amplitude and phase modulations with an average period of 1204 days, but both the cycle length and the strength of the modulation are subjected to considerable variations. A possible quintuplet component in the Fourier spectrum and additional period changes were also detected. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elimination of long‐term variations from chaotic light curves
Authors: Plachy E. , Kolláth Z. 
Published: October 2014

AbstractWe performed a comparative dynamical investigation of chaotic test data using the global flow reconstruction method. We demonstrate that large‐amplitude, long‐term variations may have a disturbing effect for the analysis. The Empirical Mode Decomposition method (EMD) and the Fourier filtering were tested to remove the additional variations. Test results show that the elimination of these variations significantly increased the robustness of the reconstructions. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hunting for binary Cepheids using the “lucky imaging” technique
Authors: Klagyivik P. , Szabados L. , Szing A. , Regály Zs. 
Published: October 2014

AbstractDetecting companions to Cepheids is difficult. In most cases the brightness of the pulsator masks the fainter secondary. Since Cepheids play a key role in determining the cosmic distance scale it is crucial to find binaries among the calibrating stars of the period‐luminosity relation. Here we present an ongoing observing project of searching for faint and close companions of Galactic Cepheids using the “lucky imaging” technique. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase statistics of the WMAP 7 year data
Authors: Kovács A. , Szapudi I. , Frei Z. 
Published: October 2014

AbstractWe performed a comprehensive statistical analysis using complex phases of the alm coefficients computed from the most recent data of the Wilkinson Microwave Anisotropy Probe (WMAP). Our alm was to confirm or constrain the presence of non‐Gaussianities in the data. We found phase correlations ‐ that suggest non‐Gaussianity – at high l in alm coefficients by applying various statistical tests. Most of all, we detected a non‐Gaussian signal reaching a significance of 4.7σ using random walk statistics and simulations. However, our conclusion is that the non‐Gaussian behavior is due to contamination from galactic foregrounds that show up in small scales only. When masked out the contaminated regions, we found no significant non‐Gaussianity. Furthermore, we constrained the fNL parameter using CMB simulations that mimic primordial non‐Gaussianity. Our estimate is fNL = 40 ± 200, in agreement with previous measurements and inflationary expectations. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Supermassive black hole mergers as dual sources for electromagnetic flares in the jet emission and gravitational waves
Authors: Tápai M. , Gergely L. Á. , Keresztes Z. , Wiita P.J. , Gopal‐Krishna  , Biermann P.L. 
Published: October 2014

AbstractWe present a new type of observation relating the gravitational wave emission of supermassive black hole mergers to their electromagnetic counterparts. This dual emission involves variability of a relativistic jet arising from the spin‐orbit precession of the supermassive black hole binary at its base. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synchrotron radiation of superconducting cosmic strings
Authors: Rogozin D.A. , Zadorozhna L.V. 
Published: October 2014

AbstractCosmic strings are topological defects which can be formed during the symmetry breaking phase transitions in the early Universe. Their existence finds support in modern superstring theories, both in compactification models and in theories with extended additional dimensions. Strings predicted in most grand unified models respond to external electromagnetic fields as thin superconducting wires. As they move through the cosmic magnetic fields, strings develop tremendous electric currents. Superconducting cosmic strings can serve as powerful sources of nonthermal radiation in a wide energy range, viz. as synchrotron radiation of electrons accelerated by bow shock waves which are created by the magnetosphere of strings moving relativistically through the intergalactic medium (IGM). Calculations of the expected radiation fluxes show that for typical parameters of the strings and the IGM the existing detectors can see loops at average string distances. According to our calculations they can also be observed if they are located in clusters of galaxies. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The stellar content of the young open cluster Trumpler 37
Authors: Errmann R. , Neuhäuser R. , Marschall L. , Torres G. , Mugrauer M. , Chen W.P. , Hu S.C.‐L. , Briceno C. , Chini R. , Bukowiecki Ł. , Dimitrov D.P. , Kjurkchieva D. , Jensen E.L.N. , Cohen D.H. , Wu Z.‐Y. , Pribulla T. , Vaňko M. , Krushevska V. , Budaj J. , Oasa Y. , Pandey A.K. , Fernandez M. , Kellerer A. , Marka C. 
Published: October 2014

AbstractWith an apparent cluster diameter of 1.5° and an age of 4 Myr, Trumpler 37 is an ideal target for photometric monitoring of young stars as well as for the search of planetary transits, eclipsing binaries and other sources of variability. The YETI consortium has monitored Trumpler 37 throughout 2010 and 2011 to obtain a comprehensive view of variable phenomena in this region. In this first paper we present the cluster properties and membership determination as derived from an extensive investigation of the literature. We also compared the coordinate list to some YETI images. For 1872 stars we found literature data. Among them 774 have high probability of being member and 125 a medium probability. Based on infrared data we re‐calculate a cluster extinction of 0.9–1.2 mag. We can confirm the age and distance to be 3–5 Myr and870 pc. Stellar masses are determined from theoretical models and the mass function is fitted with a power‐law index of α = 1.90 (0.1–0.4 M⊙) and α = 1.12 (1–10 M⊙). (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Element‐abundance inhomogeneity of interstellar matter as it follows from the chemical composition of the O‐type supergiants HDE 226868 (Cyg X‐1) and α Cam
Authors: Bochkarev N.G. , Karitskaya E.A. , Shimanskii V.V. , Galazutdinov G.A. 
Published: October 2014

AbstractBy means of synthetic spectrum modeling with non‐LTE effects, we determined element abundances in the atmospheres of two O supergiants with similar physical characteristics: HDE 226868 (the optical component of Cyg X‐1) and α Cam. These objects are situated at the distance about 2.5 kpc from each other. HDE 226868 has higher abundances compared to α Cam. The differences of Al, S, Zn, and averaged CNO abundances are within 0.15–0.30 dex. This is in a good qualitative agreement with the inhomogeneity of the heavy‐element distribution over the Galactic disk derived by Luck et al. (2006) from Cepheids. This finding confirms the inhomogeneity of chemical‐element distribution on the scale of 2 kpc and is in agreement with the concept of interstellar‐matter superclouds preserving their intrinsic particularities on a time scale in excess of 1 Gyr. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dense cores in the dark cloud complex LDN 1188
Authors: Verebélyi E. , Könyves V. , Nikolić S. , Kiss Cs. , Moór A. , Äbrahám P. , Kun M. 
Published: October 2014

AbstractWe present a molecular line emission study of the LDN 1188 dark cloud complex located in Cepheus. In this work we focused on the densest parts of the cloud and on the close neighbourhood of infrared point sources. We made ammonia mapping with the Effelsberg 100 m radio telescope and identified 3 dense cores. CS(1–0), CS(2–1) and HCO+(1–0) measurements performed with the Onsala 20 m telescope revealed the distribution of dense molecular material. The molecular line measurements were supplemented by mapping the dust emission at 1.2 mm in some selected directions using the IRAM 30 m telescope. With these data we could work out a likely evolutionary sequence in this dark cloud complex. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
SOLARIS: Software for planet formation and orbital integrations
Authors: Süli Á. 
Published: October 2014

AbstractI present SOLARIS a general purpose software package for doing N‐body and planet formation simulations. SOLARIS is capable to (i) to follow the orbital evolution of the solar system's major planets and minor bodies, (ii) to study the dynamics of exoplanetary systems, and (iii) to study the early and later phases of planetary formation. The process to bring bodies with different epochs to one common epoch, i.e. synchronization is implemented. Apart from the Newtonian gravitational forces, aerodynamic drag force, and type I and II migration forces are also implemented. The code also includes a nebula model. To speed up the computation, SOLARIS treats particles with different interaction properties. Several two–body events are monitored, such as collision, ejection etc. Arbitrary chemical composition can be assigned to massive bodies and during collisions the new body's composition is based on the mergers. The input is given in XML to define the parameters in a well‐structured and flexible way. SOLARIS is designed tobe versatile and easy to use, accepting initial conditions in either Cartesian coordinates or Keplerian orbital elements. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
WSO‐UV project for high‐resolution spectroscopy and imaging
Authors: Sachkov M. , Shustov B. , Savanov I. , Gómez de Castro A.I. 
Published: October 2014

AbstractDuring the last three decades, astronomers have had practically continuous access to the 100–300 nm spectral range that is unreachable with ground‐based instruments but where astro‐physical processes can be efficiently studied with unprecedented capability since the resonance lines of the most abundant atoms and ions at temperatures between 3000 and 300000 K are in the UV. The successful International Ultraviolet Explorer (IUE) observatory, Russian ASTRON mission and successor instruments such as the COS and STIS spectrographs on‐board the Hubble Space Telescope (HST) demonstrate the major impact that observations in the UV wavelength range have had on modern astronomy. The access to space‐based observatories is very limited. For the next decade, for the post‐HST era, the World Space Observatory UltraViolet (WSO‐UV) will be the only large telescope class mission for UV observations, both spectroscopic and imaging. By its potential, the WSO‐UV mission is similar to the HST, though it exceeds the HST/STIS in sensitivity by a factor 5–10, but all the observing time will be available for UV astronomy. In this paper, we briefly outline the WSO‐UV mission model, instrumentation description, science management plan as well as some of the key science issues that WSO–UV will address during its lifetime. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the ephemeris of the eclipsing polar HU Aquarii
Authors: Schwope A.D. , Thinius B.D. 
Published: October 2014

AbstractThe magnetic cataclysmic variable HU Aquarii displayed pronounced quasi‐periodic modulations of its eclipse timing. These were interpreted in terms of the light‐travel time (LTT) effect caused by a circumbinary planet or planetary system. We report new photometric observations that revealed another precise eclipse timing for the October 2013 epoch, the first obtained in a high accretion state after many years in low or intermediate states. The eclipse was observed to occur earlier by 95.3 ± 2.0 s or 62.8 ± 2.0 s than expected for an assumed linear or quadratic ephemeris, respectively. The implied apparent strong evolution of the orbital period calls for a revision of the current planetary model or the planetary parameters. The object deserves further monitoring to uncover the true nature of the observed variability and to constrain the properties of the proposed planet or planetary system. The new observations prove that advanced amateur equipment can successfully be used in the growing field of planet search in wide circumbinary orbits via the LTT effect. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mean‐field dynamos: The old concept and some recent developments
Authors: Rädler K.‐H. 
Published: October 2014

AbstractThis article elucidates the basic ideas of electrodynamics and magnetohydrodynamics of mean fields in turbulently moving conducting fluids. It is stressed that the connection of the mean electromotive force with the mean magnetic field and its first spatial derivatives is in general neither local nor instantaneous and that quite a few claims concerning pretended failures of the mean‐field concept result from ignoring this aspect. In addition to the mean‐field dynamo mechanisms of α2 and αΩ type several others are considered. Much progress in mean‐field electrodynamics and magnetohydrodynamics results from the test‐field method for calculating the coefficients that determine the connection of the mean electromotive force with the mean magnetic field. As an important example the memory effect in homogeneous isotropic turbulence is explained. In magnetohydrodynamic turbulence there is the possibility of a mean electromotive force that is primarily independent of the mean magnetic field and labeled as Yoshizawa effect. Despite of many efforts there is so far no convincing comprehensive theory of α quenching, that is, the reduction of the α effect with growing mean magnetic field, and of the saturation of mean‐field dynamos. Steps toward such a theory are explained. Finally, some remarks on laboratory experiments with dynamos are made. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Science with Herschel: Results from the HERITAGE project
Authors: Meixner M. , Seale J. , Roman‐Duval J. , Gordon K. , the HERITAGE Team  
Published: October 2014

AbstractThe Herschel Space Observatory completed its last observation on 2013 April 29 after completing 35000 astronomical observations resulting in numerous discoveries. In this review, we describe the capabilities and general scope of the Herschel mission. In particular, we review the science results from one of the open time key programs, the HERschel Inventory of The Agents of Galaxy Evolution (HERITAGE) in the Magellanic Clouds. The HERITAGE project mapped the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC) at 100, 160, 250, 350, and 500 μm using the SPIRE/PACS parallel mode. The total global fluxes for the LMC and SMC agree with measurements by other missions, including Planck. The HERITAGE maps of the LMC and SMC are dominated by the ISM dust emission and bear most resemblance to the tracers of ISM gas rather than the stellar content of the galaxies. The overriding science goal of HER‐ITAGE is to study the life cycle of matter as traced by dust in the LMC and SMC. The far‐infrared and submillimeter emission is an effective tracer of the interstellar medium (ISM) dust, the most deeply embedded young stellar objects (YSOs) and the dust ejected by the most massive stars which are discussed briefly in this review. The HERITAGE team has delivered the maps and source catalogs created for each of the 5 bands to the Herschel Science Center archive which will hold the legacy of Herschel. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)