bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimalarial drug chloroquine counteracts activation of indoleamine (2,3)‐dioxygenase activity in human PBMC
Authors: Gostner Johanna M. , Schröcksnadel Sebastian , Becker Kathrin , Jenny Marcel , Schennach Harald , Überall Florian , Fuchs Dietmar
Published: August 2012

Antimalarial chloroquine is also used for the treatment of immune‐mediated diseases. The interference of chloroquine with interferon‐γ‐induced tryptophan breakdown and neopterin production has been investigated in human peripheral blood mononuclear cells (PBMC) in vitro. Micromolar concentrations (2–50 μM) of chloroquine dose‐dependently suppressed mitogen‐induced tryptophan breakdown in PBMC but not in the myelomonocytic THP‐1‐Blue cell line, after 48 h of treatment. In stimulated PBMC, neopterin production was super‐induced by 10 μM chloroquine, while it was significantly suppressed at a concentration of 50 μM. These anti‐inflammatory effects may relate to the therapeutic benefit of chloroquine in inflammatory conditions and may widen the spectrum of its clinical applications.
A case of repetitive nonreentrant ventriculoatrial synchrony exacerbating heart failure in dilated cardiomyopathy
Authors: Toyoshima Yuko , Inoue Koichi , Kimura Ryusuke , Doi Atsushi , Masuda Masaharu , Sotomi Yohei , Iwakura Katsuomi , Fujii Kenshi
Published: August 2012

A 67‐year‐old man with poor left ventricular function due to a dilated cardiomyopathy was implanted with an implantable cardioverter defibrillator for secondary prevention. Eight years later, he was admitted to our hospital with worsening of heart failure. An electrocardiogram showed a repetitive nonreentrant ventriculoatrial synchrony (RNRVAS). RNRVAS is a device‐related arrhythmia that can occur when a dual‐chamber pacemaker does not sense a retrograde P wave within the postventricular atrial refractory period, resulting in a repetitive ventricular pacing and noncaptured atrial pacing after the retrograde P wave. We suspected that ventricular pacing caused his heart failure and used the noncompetitive atrial pacing algorithm, which was programmed to prevent RNRVAS. The algorithm was able to prevent the arrhythmia, and the patient successfully recovered from heart failure.
THE DIALOGUE BETWEEN UNITED KINGDOM COURTS AND THE EUROPEAN COURT OF HUMAN RIGHTS
Authors: Amos Merris
Published: August 2012

In this article the scope for dialogue between UK courts and the European Court of Human Rights is considered in theory and in practice. Having demonstrated that meaningful dialogue does take place in certain circumstances, the author considers the impact of dialogue and questions whether or not there can be any further expansion in dialogue whilst avoiding negative outcomes such as confusion over the creation of human rights norms and a loss in legitimacy for national courts adjudicating upon human rights issues.
STATE LIABILITY FOR JUDICIAL DECISIONS IN EUROPEAN UNION AND INTERNATIONAL LAW
Authors: Davies Arwel
Published: August 2012

As a consequence of the state unity theory, the conduct of all state organs is attributed to the state in an undifferentiated manner. It follows that, in both international and European Union law, state liability can be based on the substance of judicial decisions despite the independence of the judicial branch. However, beyond the matter of attribution, there is a significant divergence between the two legal systems. In international law, the judicial origin of challenged decisions does not influence the application of liability criteria, whereas, in EU law, the liability criteria can be applied to judicial decisions in a tightened manner. This article has the twofold aim of establishing and explaining this difference.
WHY THE FRENCH DON'T LIKE THE BURQA:LAÏCITÉ, NATIONAL IDENTITY AND RELIGIOUS FREEDOM
Authors: Hunter-Henin Myriam
Published: August 2012

This article examines the controversies over and implications of the 2010 French ban on the covering of the face. It carries out an internal critique of the new law and, in a broader European context, questions its compatibility with the European Convention on Human Rights. It argues that the ban has strayed away from the confines of laïcité (the separation of State and religion in the public sphere) by encompassing activities and people who in no way emanate from the State. Far from being a flagship of a secularism—à la française—or a French way of life, the ban—it is argued—goes against entrenched French legal traditions and unduly conflates the concept of national identity at the cost of individual liberties, thus forgetting the true goal of secularism: the conciliation of different beliefs and values. Assuming that the defence of secularism is nevertheless (for reasons we will explore) upheld by the European Court of Human Rights as a legitimate aim pursued by the law, the French ban, it is argued, is likely to fall foul of European requirements for lack of proportionality.
THE DUTY TO GIVE REASONS FOR ADMINISTRATIVE DECISIONS IN INTERNATIONAL LAW
Authors: Hepburn Jarrod
Published: August 2012

As scholars in the Global Administrative Law project have recognized, doctrines familiar from domestic administrative systems are beginning to appear, in nascent forms, in some areas of international law. This article makes a first attempt to examine the appearance of one such doctrine, the duty to give reasons for administrative decisions, in international case-law. The existence of and rationales for this duty have been contentious in many domestic jurisdictions. The article thus considers the extent to which these debates have been replicated amongst adjudicators at the international level. The focus is on cases in the areas of WTO law, investment law and human rights law. It is found that the case law is not yet extensive, and (perhaps as a result) that no coherent picture emerges. In contrast to domestic systems, the areas examined in international law demonstrate some agreement on the desirability of the duty. However, different international adjudicators have recognized different rationales for the duty, with only limited consensus even within each area of international law studied.
Equal channel angular pressing processing routes and associated structure modification: a differential scanning calorimetry and X-ray line profile analysis
Authors: Sarkar A. , Suwas Satyam , Goran D. , Fundenberger J.-J. , Toth L.S. , Grosdidier T.
Published: August 2012

The effectiveness of different routes of equal channel angular pressing (A, Bc, and C) is studied for commercially pure copper. The stored energy and the activation energy of recrystallization for the deformed samples were quantified using differential scanning calorimetry and X-ray diffraction line profile analysis. Results of the study revealed that the dislocation density and the stored energy are higher in the case of route Bc deformed sample. The activation energy for recrystallization is lower for route Bc.
X-ray powder diffraction data for a DACH Pt dibromide, cis-[dibromo(1R,2R)-1,2-diaminocyclohexane-κN, κN′] platinum(II)
Authors: Maixner J. , Pažout R. , Nováková I. , Holakovská J. , Kačer P.
Published: August 2012

X-ray powder diffraction data, unit-cell parameters, and space group for a novel platinum-based anticancer complex cis-[dibromo(1R,2R)-1, 2-diaminocyclohexane-κN, κN′]platinum(II), cis-Pt(C6H14N2)Br2, are presented [a = 11.862(4) Å, b = 7.222(3) Å, c = 13.353(2) Å, β = 97.813(7)°, cell volume V = 1133,36 Å3, Z = 4, space group P21]. All measured lines were indexed and are consistent with the P21 space group. No detectable impurities were observed.
Structural and electrical properties of Nd1.7Ba0.3Ni0.9Cr0.1O4+δ compound
Authors: Jammali Manel , Hassen Rached Ben , Rohlicek Jan
Published: August 2012

The Nd1.7Ba0.3Ni0.9Cr0.1O4+δ polycrystalline sample was synthesized by the sol–gel process and a subsequent annealing at 1523 K in 1 atm of flowing argon. X-ray diffraction (XRD) analysis and electrical transport properties have been investigated as well. The oxygen non-stoichiometry was determined by iodometric titration. The sample shows adoption of the K2NiF4-type structure based on a tolerance factor calculation. Rietveld refinement of the crystal structure from X-ray powder diffraction data confirmed that Nd1.7Ba0.3Ni0.9Cr0.1O4+δ adopts the tetragonal structure (space group I4/mmm, Z = 2). The room temperature unit-cell parameters are determined to be a = 3.82515(2) and c = 12.47528(6) Å. The reliability factors are: RB = 0.043, Rwp = 0.012 and χ2 = 3.00. The Nd1.7Ba0.3Ni0.9Cr0.1O4+δ compound exhibits a semi-conductive behaviour. The electrical transport mechanism has been investigated and it agrees with the adiabatic small polaron hopping model in the temperature range 313 K ≤ T ≤ 708 K.
Ab initio crystal structure determination of two chain functionalized pyrroles from synchrotron X-ray powder diffraction data
Authors: da Silva Iván , López-Tosco Sara , Tejedor David , García-Tellado Fernando , González-Platas Javier
Published: August 2012

The crystal structure of two chain functionalized pyrroles, methyl 1-benzyl-5-(1-(4-chlorobenzoyloxy)-2-methoxy-2-oxoethyl)-4-(4-chlorophenyl)-1H-pyrrole-2-carboxylate and methyl 1-benzyl-4-(biphenyl-4-yl)-5-(1-(4-biphenylcarbonyloxy)-2-methoxy-2-oxoethyl)-1H-pyrrole-2-carboxylate, which are both important active candidates as antitumoral agents, have been obtained ab initio from synchrotron X-ray powder diffraction data. Both compounds crystallize in the monoclinic system (space group P21/c), with a = 20.2544(3) Å, b = 6.80442(9) Å, c = 21.1981(3) Å, β = 111.6388(9)° and a = 29.7747(6) Å, b = 6.27495(14) Å, c = 18.8525(3) Å, β = 107.053(2)°, respectively. These structures were determined using a direct space approach, by means of Monte Carlo technique, followed by Rietveld refinement.
Synthesis and X-ray diffraction data of 5-acryloyloxy-trans-2-(4-methoxyphenyl)-3-methyl-2,3-dihydrobenzo[b]furan
Authors: Sandoval Mónica V. , Henao J. A. , Bohórquez Arnold R. Romero , Kouznetsov Vladimir V.
Published: August 2012

The compound O-acryloylated 2,3-dihydrobenzo[b]furan-5-ol (2) described in the title (chemical formula C19H18O4) was synthesized through the acryloylation reaction in anhydrous dichloromethane from the corresponding trans-2-(4-methoxyphenyl)-3-methyl-2,3-dihydrobenzo[b]furan-5-ol derivative (1), an adduct easily obtained using the Lewis acid-promoted formal [3 + 2] cycloaddition reaction. Molecular characterization was performed by Fourier Transform-Infrared (FT-IR), Gas Chromatography-Mass Spectrometry (GC-MS), 1H and 13C NMR and crystallographic characterization was carried out by X-ray diffraction (XRD) of polycrystalline samples. The title compound crystallized in a monoclinic system and unit-cell parameters are reported [a = 8.067(2) Å, b = 8.803(2) Å, c = 22.405(5) Å, β = 91.62(3)°, unit-cell volume V = 1590.7(6) Å3 and Z = 4]. All measured lines were indexed with the P21/c (No. 14) space group.
Miniaturization of mechanical milling for powder X-ray diffraction
Authors: Locock Andrew J. , Chesterman David , Caird Diane , Duke M. John M.
Published: August 2012

To enable mechanical milling of small (0.1–1.0 g) samples, a cylindrical grinding vessel machined from polypropylene and furnished with tungsten carbide rods has been designed and produced for use inside the conventional jar of a McCrone Micronizing Mill. The vessel is about one-seventh the volume of the conventional jar supplied by the manufacturer. The conditions of milling for both the conventional and the miniaturized-grinding assemblies were tested using quartz sand as a limiting case. The median grain sizes of the resultant powders were measured by an X-ray gravitational-sedimentation method, with contamination from the grinding media measured by Rietveld refinement and by instrumental neutron activation analysis. The use of tungsten carbide grinding elements permits rapid wet milling of a small sample to the same median grain size in about one-third of the time required by a regular sample ground in corundum. The relative contamination (by tungsten carbide on a weight basis) using the miniaturized-grinding assembly is about 6(1)% of the proportion of corundum contamination yielded by the conventional grinding assembly.
X-ray powder diffraction data for the mineral refikite
Authors: Pažout R. , Sejkora J.
Published: August 2012

X-ray powder diffraction data, unit-cell parameters and space group for a rare natural organic mineral refikite, C20H32O2, abiet-13(15)-en-18-oic acid, are reported [a = 22.55(2) Å, b = 10.469(6) Å, c = 7.930(9) Å, unit-cell volume V = 1871.82 Å3, Z = 4 and space group P21212]. All measured lines were indexed and are consistent with the P21212 space group. No detectable impurities were observed.
Population synthesis at the crossroads
Authors: Leitherer Claus , Ekström Sylvia
Published: August 2012

The current state-of-the-art of population synthesis is reviewed. The field is currently undergoing major revisions with the recognition of several key processes as new critical ingredients. Stochastic effects can artificially enhance or suppress certain evolutionary phases and/or stellar mass regimes and introduce systematic biases in, e.g., the determination of the stellar initial mass function. Post-main-sequence evolution is often associated with irregular variations of stellar properties on ultra-short time-scales. Examples are asymptotic giant branch stars and luminous blue variables, both of which are poorly treated in the models. Stars rarely form in isolation, and the fraction of truly single stars may be very small. Therefore, stellar multiplicity must be accounted for since many systems will develop tidal interaction over the course of their evolution. Last but not least, stellar rotation can drastically increase stellar temperatures and luminosities, which in turn leads to revised mass-to-light ratios in population synthesis models.
NBursts+phot: parametric recovery of galaxy star formation histories from the simultaneous fitting of spectra and broad-band spectral energy distributions
Authors: Chilingarian Igor V. , Katkov Ivan Yu.
Published: August 2012

We present NBursts+phot, a novel technique for the parametric inversion of spectrophotometric data for unresolved stellar populations where high-resolution spectra and broadband SEDs are fitted simultaneously, helping to break the degeneracies between parameters of multi-component stellar population models.
An empirical spectral library of chemically well characterized stars for stellar population modelling
Authors: de Castro Milone André , Sansom Anne E. , Sánchez-Blázquez Patricia , Vazdekis Alexandre , Falcón-Barroso Jesus , Prieto Carlos Allende
Published: August 2012

With the goal of assembling a new generation of more realistic single stellar population (SSP) models, we have obtained magnesium abundances for nearly 80% of the stars of the widely employed MILES empirical spectral library. Additional spectroscopic observations of carefully selected stars have recently been obtained to improve the parametric coverage of this library. Here we report on: (i) the framework of Mg abundance determination carried out at mid-resolution, (ii) the newly acquired data, and (iii) the preliminary steps towards modelling stellar populations.
A first glance into the Spectral Energy Distributions of Single Stellar Populations in the Infrared range
Authors: Meneses-Goytia Sofia , Peletier Reynier F.
Published: August 2012

The present work shows the Spectral Energy Distributions (SEDs) in the infrared using the IRTF stellar library, obtained using models based on Single Stellar population Models (SSP). We have focused on the K band in order to compare with observables of elliptical galaxies. We also present the comparisons of our models with velocity dispersions, ages and metallicities obtained with models in the optical range.
A Bayesian approach to quantify the uncertainties in the determination of galaxy properties derived from spectral fits
Authors: Magris C. Gladis , Mateu Cecilia , Bruzual A. Gustavo
Published: August 2012

We use a bayesian formalism to quantify the uncertainties in the determination of the luminous mass and age of the dominant stellar population in a galaxy obtained from simple spectral fits. The analysis is performed over a sample of synthetic spectra covering a wide range of star formation histories and seen at different ages and redshifts. Using the bayesian approach we can establish quantitatively the uncertainties in the parameters derived from these fits in a straightforward manner, which is not possible using some simple algorithms, e.g. GASPEX, a non-negative least-square fitting algorithm.
The UV upturn phenomenon in the hierarchical universe
Authors: Lee Jaehyun , Yi Sukyoung K.
Published: August 2012

Recent studies show that an old stellar population with high metallicity in the monolithic paradigm can explain the UV upturn. Numerical simulations and empirical studies however point out that massive early-type galaxies have evolved hierarchically with an extended star formation history. This obviously has an impact on our traditional understanding on the UV upturn and requires a new investigation on its origin. We report on our investigation on the evolutionary history of model galaxy SEDs in the hierarchical scenario. The use of conventional population models (calibrated to the monolithic picture) in combination with merger trees and extended star formation fails to reproduce the observed UV upturn. If a hierarchical picture is thought to be more realistic than a monolithic one, new calibration on the population models is required.
Star formation history and the SED of galaxies: insights from resolved stars
Authors: Johnson Benjamin D. , Weisz Daniel R.
Published: August 2012

The star formation history (SFH) of galaxies is a principle uncertainty in SED modeling, and simple parameterizations of the SFH in typical SED fitting techniques may introduce biases in the resulting derived parameters. It is possible to constrain the SFH of galaxies more tightly through the observations of resolved stellar colour-magnitude diagrams with HST. This work is a first attempt to combine constraints on galaxy SFH from resolved stars with broadband SED modeling from the UV to the IR. This combination allows for the effects of different realistic SFHs on the SED to be quantified.
Direct constraints on the impact of TP-AGB stars on the SED of galaxies from near-infrared spectroscopy
Authors: Zibetti Stefano , Gallazzi Anna , Charlot Stéphane , Pasquali Anna , Pierini Daniele
Published: August 2012

We present new spectro-photometric NIR observations of 16 post-starburst galaxies especially designed to test for the presence of strong carbon features of thermally pulsing AGB (TP-AGB) stars, as predicted by recent models of stellar population synthesis. Selection based on clear spectroscopic optical features indicating the strong predominance of stellar populations with ages between 0.5 and 1.5 Gyr and redshift around 0.2 allows us to probe the spectral region that is most affected by the carbon features of TP-AGB stars (unaccessible from the ground for z ~ 0 galaxies) in the evolutionary phase when their impact on the IR luminosity is maximum. Nevertheless, none of the observed galaxies display such features. Moreover the NIR fluxes relative to optical are consistent with those predicted by the original Bruzual & Charlot (2003) models, where the impact of TP-AGB stars is much lower than has been recently advocated.
Spectral fitting of SDSS passive galaxies with α-enhanced single stellar populations
Authors: Gomes Jean Michel , Coelho Paula
Published: August 2012

The power of population synthesis as a mean to estimate the star-formation and chemical histories of galaxies has been well established in the last decade. The major developments were due to a huge avalanche of methods, codes and high-quality galaxy data sets, such as the 2dF, 6dF and SDSS surveys. Semi-empirical spectral synthesis allows for the decomposition of a galaxy spectrum in terms of linear combinations of base elements, i.e. Single Stellar Populations (SSPs) of different ages and metallicities, which are computed from evolutionary synthesis codes (BPASS, GALEV, GALAXEV, MILES, PÉGASE, etc. . .), containing distinct ingredients like: stellar library, evolutionary tracks, metallicities and Initial Mass Function. In general, they have solar-scaled relative abundances, but this is about to change with the unfolding of new α-enhanced SSP models (Coelho et al. 2007). However, passive galaxies have some spectral features corresponding to “enhanced-ratios” ([E/Fe]), like O, Ne, Si, S, Mg, Na, C and N over Fe that are not well modeled using solar-scaled SSPs (Trager et al. 2000), leading to residuals between observed and modeled spectra, which also correlate with the velocity dispersion (σ*) and stellar mass (M*): Massive galaxies exhibit a larger [E/Fe] discrepancy than less massive ones. This result can be interpreted as a signature of distinct previous star-formation efficiencies in passive galaxies, leading to distinctive ratios of type Ia and II SNe.

We have applied the starlight spectral synthesis code (Cid Fernandes et al. 2005) to a sample of ~ 1000 passive galaxies from the SDSS DR7 with a S/N at the continuum ≥ 20 to investigate possible enhancements in the derived [E/Fe] ratios. Three sets of SSPs based on Coelho et al. (2007) theoretical models and Walcher et al. (2009) prescriptions were computed for [α/Fe]=0.0, [α/Fe]=0.2 and [α/Fe]=0.4. Our aim is to determine: (1) the quality of the fits, (2) the mean stellar age and metallicity distributions, and (3) the star-formation history of passive galaxies.

Using [α/Fe]=0.0 SSPs, we have identified the strongest residuals in the CN (4142.125-4177.125 Å), Na D (5876.875-5909.375 Å) and Mg (5069.125-5196.625 Å) bands. On the other hand, [α/Fe]=0.2 and [α/Fe]=0.4 SSP models tend to reproduce better the Mg band, as compared to solar-scaled SSPs ([α/Fe]=0.0). The residuals are decreased by 1.77 Å ([α/Fe]=0.2) and 2.92 Å ([α/Fe]=0.4). However, as expected, these α--enhanced models lead to worse fits for the CN and Na D bands. These residuals may even reach up to 2.08 Å (CN) and 4.20 Å (Na D), using [α/Fe]=0.2 SSPs and 2.28 Å (CN) and 7.94 Å (Na D), using [α/Fe]=0.4 SSPs.

In terms of mean stellar ages and metallicities, we obtain non-negligible biases in both quantities when we compare the solar-scaled SSPs with α-enhanced ones, which tend to have mean stellar ages by 0.12 dex ([α/Fe]=0.2) and 0.14 dex ([α/Fe]=0.4) higher and mean stellar metallicities by 0.1 dex ([α/Fe]=0.2) and 0.2 dex ([α/Fe]=0.4) lower.
Multi-component parametric inversion of galaxy kinematics and stellar populations using full spectral fitting
Authors: Katkov Ivan Yu. , Chilingarian Igor V.
Published: August 2012

The stellar line-of-sight velocity distribution (LOSVD) can be strongly asymmetric in regions where the light contributions of both disc and bulge in spiral and lenticular galaxies are comparable. Existing techniques for the stellar kinematics analysis do not take into account the difference of disc and bulge stellar populations. Here we present a novel approach to the analysis of stellar kinematics and stellar populations. We use a two-component model of spectra where different stellar population components are convolved with pure Gaussian LOSVDs. For this model we present Monte-Carlo simulations demonstrating degeneracies between the parameters.
Chemical and physical properties of interstellar dust
Authors: Tielens A. G. G. M.
Published: August 2012

The characteristics of interstellar dust reflect a complex interplay between stellar injection of stardust, destruction in the ISM, and regrowth in clouds. Astronomical observations and analysis of stardust isolated from meteorites have revealed a highly diverse interstellar and circumstellar grain inventory, including both amorphous materials and highly crystalline compounds (silicates and carbon). This review summarizes this dust budget and inventory. Interstellar dust is highly processed during its sojourn from its birthsite (stellar ejecta) to its incorporation into protoplanetary systems. Processing by strong shocks due to supernova explosions is particularly important. Sputtering by impacting gas ions in shocks in the intercloud medium of the ISM is counteracted by accretion in cloud phases and their balance sets the observed, interstellar, elemental depletion patterns. Astronomical and meteoritical-stardust evidence for these processes is reviewed and it is concluded that dust formation in the ISM is very rapid. Not surprisingly, the characteristics of interstellar dust are expected to vary widely reflecting local stellar sources, the effects of SNe processing, and the interstellar accretion process.
The processing of radiation by dust in galaxies
Authors: Siebenmorgen Ralf , Heymann Frank
Published: August 2012

Optical/UV photons and even harder radiation components in galaxies are absorbed and scattered by dust and re-emitted at infrared wavelengths. For a better understanding of the obscured regions of the galaxies detailed models of the interaction of photons with dust grains and the propagation of light are required. A problem which can only be solved by means of numerical solution of the radiative transfer equation. As a prologue we present high angular mid IR observations of galactic nuclei in the spirit of future ELT instrumentation. Dust models are discussed, which are suited to fit the extinction curves and relevant to compute the emission of external galaxies. Self-consistent radiative transfer models have been presented in spherical symmetry for starburst nuclei, in two dimensions for disk galaxies (spirals) and, more recently, in three dimensional configuration of the dust density distribution. For the latter, a highlighting example is the clumpy dust tori around AGN. Modern advances in the field are reviewed which are either based on a more detailed physical picture or progress in computational sciences.
Investigations of dust heating in M81, M83 and NGC 2403 with Herschel and Spitzer
Authors: Bendo George J. ,   the Herschel-SPIRE Local Galaxies Guaranteed Time Programs
Published: August 2012

We use Herschel Space Observatory and Spitzer Space Telescope 70-500 μm data along with ground-based optical and near-infrared data to understand how dust heating in the nearby face-on spiral galaxies M81, M83, and NGC 2403 is affected by the starlight from all stars and by the radiation from star-forming regions. We find that 70/160 μm flux density ratios tend to be more strongly influenced by star-forming regions. However, the 250/350 and 350/500 μm micron flux density ratios are more strongly affected by the light from the total stellar populations, suggesting that the dust emission at > 250 μm originates predominantly from a component that is colder than the dust seen at <160 μm and that is relatively unaffected by star formation activity. We conclude by discussing the implications of this for modelling the spectral energy distributions of both nearby and more distant galaxies and for using far-infrared dust emission to trace star formation.
Spectral Energy Distributions of a set of H ii regions in M33 (HerM33es)
Authors: Relaño Monica , Verley Simon , Pérez Isabel , Kramer Carsten , Xilouris Manolis , Boquien Médéric , Braine Jonathan , Calzetti Daniela , Henkel Christian ,   the HerM33es Team
Published: August 2012

Within the framework of the HerM33es Key Project for Herschel and in combination with multi-wavelength data, we study the Spectral Energy Distribution (SED) of a set of H ii regions in the Local Group Galaxy M33. Using the Hα emission, we perform a classification of a selected H ii region sample in terms of morphology, separating the objects in filled, mixed, shell and clear shell objects. We obtain the SED for each H ii region as well as a representative SED for each class of objects. We also study the emission distribution of each band within the regions. We find different trends in the SEDs for each morphological type that are related to properties of the dust and their associated stellar cluster. The emission distribution of each band within the region is different for each morphological type of object.
Variation in the dust spectral index across M33
Authors: Tabatabaei Fatemeh S. , Braine Jonathan , Kramer Carsten , Xilouris Manolis , Boquien Mederic , Verley Simon , Schinnerer Eva , Calzetti Daniela , Combes Francoise , Israel Frank , Henkel Christian ,   The HerM33es Team
Published: August 2012

Using the Herschel PACS and SPIRE FIR/submm data, we investigate variations in the dust spectral index β in the nearby spiral galaxy M33 at a linear resolution of 160 pc. We use an iteration method in two different approaches, single and two-component modified black body models. In both approaches, β is higher in the central disk than in the outer disk similar to the dust temperature. There is a positive correlation between β and Hα as well as with the molecular gas traced by CO(2-1). A Monte-Carlo simulation shows that the physical parameters are better constrained when using the two-component model.
Ionization of the diffuse gas in galaxies: hot low-mass evolved stars at work
Authors: Flores-Fajardo N. , Morisset C. , Stasińska G. , Binette L.
Published: August 2012

We revisit the question of the ionization of the diffuse medium in late type galaxies, by studying NGC 891. The most important challenge for the models considered so far was the observed increase of [O iii]/Hβ, [O iii]/Hβ, and [N ii]\Hα with increasing distance to the galactic plane. We propose a scenario based on the expected population of massive OB stars and hot low-mass evolved stars (HOLMES) in this galaxy to explain this observational fact. In the framework of this scenario we construct a finely meshed grid of photoionization models. For each value of the galactic latitude z we look for the models which simultaneously fit the observed values of the [O iii]/Hβ, [O ii]/Hβ, and [N ii]\Hα ratios. For each value of z we find a range of solutions which depends on the value of the oxygen abundance. The models which fit the observations indicate a systematic decrease of the electron density with increasing z. They become dominated by the HOLMES with increasing z only when restricting to solar oxygen abundance models, which argues that the metallicity above the galactic plane should be close to solar. They also indicate that N/O increases with increasing z.
Dust in dwarf galaxies: The case of NGC 4214
Authors: Lisenfeld U. , Hermelo I. , Relaño M. , Tuffs R. J. , Popescu C. C. , Fischera J. , Groves B.
Published: August 2012

We have carried out a detailed modelling of the dust heating and emission in the nearby, starbursting dwarf galaxy NGC 4214. Due to its proximity and the great wealth of data from the UV to the millimeter range (from GALEX, HST, Spitzer, Herschel, Planck and IRAM) it is possible to separately model the emission from HII regions and their associated photodissociation regions (PDRs) and the emission from diffuse dust. Furthermore, most model parameters can be directly determined from the data leaving very few free parameters. We can fit both the emission from HII+PDR regions and the diffuse emission in NGC 4214 with these models with “normal” dust properties and realistic parameters.
Modeling the dust Spectral Energy Distribution of NGC 4214
Authors: Hermelo Israel , Lisenfeld Ute , Relaño Mónica , Tuffs Richard J. , Popescu Cristina C. , Fischera Jörg , Groves Brent
Published: August 2012

We have carried out a detailed modeling of the dust Spectral Energy Distribution (SED) of the nearby, starbursting dwarf galaxy NGC 4214. A key point of our modeling is that we distinguish the emission from (i) HII regions and their associated photodissociation regions (PDRs) and (ii) diffuse dust. For both components we apply templates from the literature calculated with a realistic geometry and including radiation transfer. The large amount of existing data from the ultraviolet (UV) to the radio allows the direct measurement of most of the input parameters of the models. We achieve a good fit for the total dust SED of NGC 4214. In the present contribution we describe the available data, the data reduction and the determination of the model parameters, whereas a description of the general outline of our work is presented in the contribution of Lisenfeld et al. in this volume.
Optical SED models of galaxy mergers
Authors: Snyder Gregory F. , Cox T. J. , Hayward Christopher C. , Hernquist Lars , Jonsson Patrik
Published: August 2012

I discuss recent work in which we construct models of poststarburst galaxies by combining fully three-dimensional hydrodynamic simulations of galaxy mergers with radiative transfer calculations of dust attenuation. The poststarburst signatures can occur shortly after a bright starburst phase in gas-rich mergers, and thus offer a unique opportunity to study the formation of bulges and the effects of feedback. Several additional applications of spatially-resolved spectroscopic models of interacting galaxies include multi-wavelength studies of AGN/starburst diagnostics, mock integral field unit data to interpret the evolution of ULIRGs, and the ‘Green Valley’.

Optical spectra of simulated major gas-rich galaxy mergers can be found at http://www.cfa.harvard.edu/~gsnyder
The SEDs of interacting galaxies
Authors: Lanz Lauranne , Brassington Nicola , Zezas Andreas , Smith Howard A. , Ashby Matthew L. N. , da Cunha Elisabete , Klein Christopher , Jonsson Patrik , Hayward Christopher C. , Hernquist Lars , Fazio Giovanni
Published: August 2012

The evolution of galaxies is greatly influenced by their interactions. As part of a program to study interacting galaxies, we have measured and modeled the spectral energy distributions (SEDs) from the ultraviolet (UV) to the far-infrared (FIR). We describe the constraints imposed on star formation histories by these SEDs, and the variations therein seen across the interaction sequence, and we compare the results of different star formation rate prescriptions applied to the data. The sample itself is based on the Spitzer Interacting Galaxy Survey (SIGS) of 111 galaxies in 50 systems, a project designed to probe a range of galaxy interaction parameters in the infrared. Our SEDs combine the Spitzer results with multiwavelength data from other missions, in particular GALEX and Herschel. The subset presented here is the sample for which FIR Herschel observations are currently publicly available.
Properties of mid- to far-infrared dust emission in the nearby superwind galaxy M82
Authors: Arimatsu Ko , Onaka Takashi , Sakon Itsuki , Egusa Fumi , Kaneda Hidehiro
Published: August 2012

Using the reconstructed imaging data obtained with the Infrared Camera (IRC) on board AKARI, mid-infrared (MIR; 5-30 μm) emission characteristics of the superwind galaxy M82 are studied. The MIR images at four wavelengths (7, 11, 15, and 24 μm) show extended (out to distances of 4 kpc) emission mainly from polycyclic aromatic hydrocarbons (PAHs). The MIR SED of M82 halo is surprisingly constant. Using far-infrared imaging data obtained by Herschel/SPIRE, we reveal that the PAH abundance relative to the big (sub-micron sized) grains radially increases by about a factor of three. These results imply that PAHs may be formed in small and dense molecular clumps in the halo and efficiently supplied to the intergalactic space by the galactic superwind.
The Mid-Infrared luminosity function of galaxies using the AKARI mid-infrared All-Sky Survey Catalogue
Authors: Toba Y. , Oyabu S. , Matsuhara H. , Ishihara D. , Malkan M. , Wada T. , Kataza H. , Ohyama Y. , Takita S.
Published: August 2012

We present the first determination of the 18 μm luminosity function (LF) of galaxies at 0.006 < z < 0.7 (the average redshift is ~ 0.04) using the AKARI mid-infrared All-Sky Survey catalogue. We have selected a 18 μm flux-limited sample of 243 galaxies from the catalogue in the SDSS spectroscopic region. We then classified the sample into four types; Seyfert 1 galaxies (including QSOs), Seyfert 2 galaxies, LINERs and Star-Forming galaxies using mainly [OIII]/Hβ vs. [NII]/Hα line ratios obtained from the SDSS.

As a result of constructing Seyfert 1 and Seyfert 2 LFs, we found the following results; (i) the number density ratio of Seyfert 2s to Seyfert 1s is 3.98 ± 0.41 obtained from Sy1 and Sy2 LFs; this value is larger than the results obtained from optical LFs. (ii) the fraction of Sy2s in the entire AGNs may be anti-correlated with 18 μm luminosity. These results suggest that the torus structure probably depends on the mid-infrared luminosity of AGNs and most of the AGNs in the local Universe are obscured by dust.
Optically faint radio sources: reborn AGN?
Authors: Filho Mercedes E. , Brinchmann Jarle , Lobo Catarina , Antón Sonia
Published: August 2012

We have discovered eight relatively strong radio sources that have no optical counterparts. A NIR follow-up has detected faint (17–20 mag) host galaxies in all targets. In general, the radio properties are similar to those observed in 3CRR sources but the optical-radio slopes are consistent with moderate to high redshift (z < 4) GHz-peaked spectrum sources. Our results suggest that these are galaxies whose black hole has been recently re-ignited into activity but that retain large-scale radio structures, signatures of previous AGN activity.
Stellar populations in the centers of nearby galaxies
Authors: Gomes Jean Michel , Filho Mercedes E. , Ho Luis C.
Published: August 2012

The great amount of data observed in recent years coupled with modelling using evolutionary synthesis codes (BPASS, COELHO, GALAXEV, GALEV, MILES, PÉGASE, etc. . .) to compute Single Stellar Populations (SSPs) and the availability of fast and ingenious spectral synthesis codes such asstarlight, ULySS and VESPA, have significantly shed light on our knowledge about the formation and evolution of galaxies. However, there are still open issues concerning the stellar populations in nearby galaxies, particularly those harbouring Active Galactic Nuclei (AGN): can stellar populations mimic nuclear activity, leading to a misclassification based on optical emission line ratios (Stasińskaet al. 2008)? We have applied thestarlightcode (Cid Fernandeset al. 2005) to a well studied sample of nearby galaxies' nuclear spectra (r < ~ 200 pc), observed with the Hale 5 m telescope at Palomar Observatory in two different regions: ~ 4230-5110 Å and ~ 6210-6860 Å (Hoet al. 1995), with spectral resolutions of approximately 4 Å, and 2.5 Å. The aim is to properly derive the star-formation history (SFH), mean stellar age and metallicity and total stellar mass. Our results show that the star-formation history of Seyfert galaxies are very heterogeneous, i.e. these are composed of young, intermediate and old stellar populations, while the SFH of Low-Ionization Nuclear Emission-Line Regions (LINERs) are basically composed of old stellar populations. The absence of young stars in LINERs indicates that these are not responsible for the observed low-ionization emission lines. Furthermore, although a significant fraction of AGN spectra require a featureless continuum in their Spectral Energy Distribution (SED) modelling, this is not an indicative of the presence of an AGN, instead the continuum may simulate the presence of young stellar populations. The main objective of this research is to complement the study of spectroscopic parameters from 486 galaxies analyzed by Hoet al. (1995) that are public available in the VizieR catalog (Hoet al. 1997, 2009) and provide information about their stellar population content by means of thestarlight. The base of Simple Stellar Populations used here was taken from Bruzual & Charlot (2003) and spans 25 ages (from 1 Myr to 18 Gyr) and 6 metallicities (Z = 0.005, 0.02, 0.2, 0.4, 1 & 2.5Z⊙).
The star-formation histories of early-type galaxies from ATLAS3D
Authors: McDermid Richard M. , Alatalo Katherine , Blitz Leo , Bois Maxime , Bournaud Frédéric , Bureau Martin , Cappellari Michele , Crocker Alison F. , Davies Roger L. , Davis Tim A. , de Zeeuw P.T. , Duc Pierre-Alain , Emsellem Eric , Khochfar Sadegh , Krajnović Davor , Kuntschner Harald , Lablanche Pierre-Yves , Morganti Rafaella , Naab Thorsten , Oosterloo Tom , Sarzi Marc , Scott Nic , Serra Paolo , Weijmans Anne-Marie , Young Lisa M.
Published: August 2012

We present an exploration of the integrated stellar populations of early-type galaxies (ETGs) from the ATLAS3D survey. We use two approaches: firstly the application of line-indices interpreted through single stellar population (SSP) models, which provide a single value of age, metallicity and abundance ratio. And secondly, by fitting a linear combination of SSP spectra to our data, smoothly weighted in the free parameters of age and metallicity, thereby inferring a star-formation history of these galaxies. Despite the significant differences in these approaches, we obtain generally consistent results, such that galaxies that are more massive appear older with enhanced abundance ratios using line indices, and have shorter star-formation histories weighted to early times. We highlight two limitations of the index-SSP approach. Firstly the SSP-equivalent ages belie the fact that ETGs are overwhelmingly composed of ancient stars. Secondly, the young stellar contributions implied in our star formation histories are required to obtain realistic UV-optical colours. We remark that, even fitting solar-abundance models, we can recover a star-formation duration that correlates with the measured alpha-enhancement, in agreement with other recent work.
Constrain the stellar population gradient of elliptical galaxies with SED
Authors: Shao Zhengyi
Published: August 2012

We use multiple wavelength photometric data, from Optical to NIR, to determine the radial gradient of stellar populations of nearby elliptical galaxies. Empirical model, such as the Sersic profile, is assumed to describe the radial stellar distribution, and the metallicity gradient is parameterlized in this model. The PSF effects of different wavebands are also involved to predict the photometric profiles which can be compared with observational surface brightness profile directly. For most of elliptical galaxies, they have negative gradients, which means their central parts is metal rich than outer parts. We also found the gradient is significantly correlated to the stellar mass of the whole galaxy. More massive elliptical galaxies have shallower gradients. But for our sample galaxies, their is no correlations between Sersic n and mass, and between Sersic n and gradient can be found.
Outer stellar disks of lenticular galaxies
Authors: Sil'chenko Olga K.
Published: August 2012

By studying the radial distribution of the properties of stellar populations in 15 nearby S0 galaxies, I have found that the outer stellar disks are mostly old, with SSP-equivalent ages of 8–15 Gyr, often being older than the bulges. This fact throws doubt on the currently accepted paradigm that S0 galaxies were formed at z=0.4 through the quenching of star formation in spiral galaxies.
Dust and PAHs in X-ray plasma of elliptical galaxies
Authors: Kaneda Hidehiro , Onaka Takashi , Suzuki Toyoaki , Mori Tatsuya , Yamagishi Mitsuyoshi , Kondo Toru , Yasuda Akiko
Published: August 2012

Many elliptical galaxies possess an appreciable amount of X-ray-emitting hot plasma, providing a harsh interstellar environment for the survival of dust grains and polycyclic aromatic hydrocarbons (PAHs). Despite such a hostile environment, it has been found that a significant fraction of X-ray elliptical galaxies contain a considerable amount of dust, which cannot be explained solely from replenishment by old stars. Some of them even show the presence of PAHs. We present the results of AKARI and Spitzer observations of dust and PAHs in X-ray elliptical galaxies. We investigate their possible origins and discuss the implications of their presence for the evolution of elliptical galaxies.
Panchromatic properties of galaxies in wide-field optical spectroscopic and photometric surveys
Authors: Driver Simon P.
Published: August 2012

The past 15 years have seen an explosion in the number of redshifts recovered via wide area spectroscopic surveys. At the current time there are approximately 2 million spectroscopic galaxy redshifts known (and rising) which represents an extraordinary growth since the pioneering work of Marc Davis and John Huchra. Similarly there has been a parallel explosion in wavelength coverage with imaging surveys progressing from single band, to multi-band, to truly multiwavelength or pan-chromatic involving the coordination of multiple facilities. With these empirically motivated studies has come a wealth of new discoveries impacting almost all areas of astrophysics. Today individual surveys, as best demonstrated by the Sloan Digital Sky Survey, now rank shoulder-to-shoulder alongside major facilities. In the coming years this trend is set to continue as we begin the process of designing and conducting the next generation of spectroscopic surveys supported by multi-facility wavelength coverage.
Far-infrared and sub-millimeter properties of SDSS galaxies in the Herschel ATLAS SDP Field
Authors: Lam Man I. , Wu Hong , Zhu Yi-Nan
Published: August 2012

Using data from the new infrared facility the Herschel Space Observatory, we have analyzed correlations between morphological type, far-infrared (FIR) luminosity, and Hα luminosity for star-forming galaxies, composite galaxies, and AGNs. We found a trend in scatter from 100μm to 500μm, which indicates that the submillimeter bands are not a good star formation tracer in these galaxies, being contaminated either by the old stellar population or by the interstellar medium (ISM). AGNs have no significant effect on our fitting results since the far-infrared to submillimeter emission is from cold dust/large dust grains.
Dust effects on the derived Sérsic indexes of disks and bulges in spiral galaxies
Authors: Pastrav Bogdan A. , Popescu Cristina C. , Tuffs Richard J. , Sansom Anne E.
Published: August 2012

We present a theoretical study that quantifies the effect of dust on the derived Sérsic indexes of disks and bulges. The changes in the derived parameters from their intrinsic values (as seen in the absence of dust) were obtained by fitting Sérsic distributions on simulated images of disks and bulges produced using radiative transfer calculations and the model of Popescu et al. (2011). We found that dust has the effect of lowering the measured Sérsic index in most cases, with stronger effects for disks and bulges seen through more optically thick lines of sight.
What triggers star formation in galaxies?
Authors: Elmegreen Bruce G.
Published: August 2012

Processes that promote the formation of dense cold clouds in the interstellar media of galaxies are reviewed. Those that involve background stellar mass include two-fluid instabilities, spiral density wave shocking, and bar accretion. Young stellar pressures trigger gas accumulation on the periphery of cleared cavities, which often take the form of rings by the time new stars form. Stellar pressures also trigger star formation in bright-rim structures, directly squeezing the pre-existing clumps in nearby clouds and clearing out the lower density gas between them. Observations of these processes are common. How they fit into the empirical star formation laws, which relate the star formation rate primarily to the gas density, is unclear. Most likely, star formation follows directly from the formation of cold dense gas, whatever the origin of that gas. If the average pressure from the weight of the gas layer is large enough to produce a high molecular fraction in the ambient medium, then star formation should follow from a variety of processes that combine and lose their distinctive origins. Pressurized triggering might have more influence on the star formation rate in regions with low average molecular fraction. This implies, for example, that the arm/interarm ratio of star formation efficiency should be higher in the outer regions of galaxies than in the main disks.