bluuebunny/crossref_metadata_2025 huggingface dataset:
Far-IR to Submm SEDs for local galaxies: Herschel, Planck and the HRS
Authors: Clements David L ,   The Herschel Reference Sample Team
Published: August 2012

The Herschel Space Observatory and the Planck satellite are providing radical improvements to our knowledge of the spectral energy distributions of galaxies in the far-IR and submm. We here present the results of the first combination of Herschel and Planck fluxes of local galaxies from the Herschel Reference Sample (HRS) survey, covering galaxies at distances between 15 and 25 Mpc. This combination provides information on SEDs in eight bands from 60μm, using IRAS, to 1.4mm using Planck. We apply a similar fitting procedure to this data as applied to the Planck ERCSC-detected nearby galaxies and confirm the result that dust significantly colder than 20K is common in local galaxies. It is early days for this kind of study, but it is clear that the new generation of satellites are already adding considerably to our knowledge of the far-IR/submm properties of galaxies.
The spectral energy distributions of the entire Herschel Reference Survey
Authors: Ciesla Laure ,   the Herschel-SPIRE Local Galaxies Guaranteed Time Programs
Published: August 2012

We present the spectral energy distributions (SED) of the 323 galaxies of the Herschel Reference Survey. In order to provide templates for nearby galaxies calibrated on physical parameters, we computed mean SEDs per bin of morphological types and stellar masses. They will be very useful to study more distant galaxies and their evolution with redshift. This preliminary work aims to study how the most commonly used libraries (Chary & Elbaz 2001, Dale & Helou 2002 and Draine & Li 2007) reproduce the far-infrared emission of galaxies. First results show that they reproduce well the far-infrared part of mean SEDs. For single galaxies the Draine & Li (2007) models seem to reproduce very well the far-infrared emission, as does the Dale & Helou (2002).
Far Infrared Luminosity Function of Local Galaxies in the AKARI Deep Field South
Authors: Sedgwick Chris , Serjeant Stephen , Pearson Chris , Matsuura Shuji , Shirahata Mai , Oyabu Shinki , Goto Tomotsugu , Matsuhara Hideo , Clements D.L. , Negrello Mattia , Takagi Toshinobu , White Glenn J.
Published: August 2012

We present the first far-infrared luminosity function in the AKARI Deep Field South, a premier deep field of the AKARI Space Telescope, using spectroscopic redshifts obtained with AAOmega. To date, we have found spectroscopic redshifts for 389 galaxies in this field and have measured the local (z<0.25) 90 μm luminosity function using about one-third of these redshifts. The results are in reasonable agreement with recent theoretical predictions.
MAGPHYS: a publicly available tool to interpret observed galaxy SEDs
Authors: da Cunha Elisabete , Charlot Stéphane , Dunne Loretta , Smith Dan , Rowlands Kate
Published: August 2012

We present a simple, physically-motivated model to interpret consistently the emission from galaxies at ultraviolet, optical and infrared wavelengths. We combine this model with a Bayesian method to obtain robust statistical constraints on key parameters describing the stellar content, star formation activity and dust content of galaxies. Our model is now publicly available via a user-friendly code package, MAGPHYS at www.iap.fr/magphys. We present an application of this model to interpret a sample of ~1400 local (z<0.5) galaxies from the H-ATLAS survey. We find that, for these galaxies, the diffuse interstellar medium, powered mainly by stars older than 10 Myr, accounts for about half the total infrared luminosity. We discuss the implications of this result to the use of star formation rate indicators based on total infrared luminosity.
Measuring SEDs for individual galaxy components
Authors: Bamford Steven P. , Häußler Boris , Rojas Alex , Vika Marina , Cresswell Jim
Published: August 2012

Our project, ‘MegaMorph’, is developing a next-generation tool for decomposing galaxies, in terms of both their structures and stellar populations. By combining data from UV to NIR wavelengths, accounting for morphological peculiarities using non-parametric components, and utilising efficient likelihood sampling methods, we are working to significantly improve the robustness and accuracy of galaxy decomposition. Applying these new techniques to modern large surveys will provide us with a deeper understanding of galaxies.
Publicly available database for spectral line measurements of SDSS DR7 galaxies
Authors: Oh Kyuseok , Sarzi Marc , Schawinski Kevin , Yi Sukyoung K.
Published: August 2012

We present a new database of absorption and emission-line measurements based on the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Using the publicly available penalized pixel-fitting (pPXF) and gas and absorption line fitting (gandalf) codes, our work improve the existing measurements for stellar kinematics, the strength of various absorption line features, and the flux and width of the emissions from different species of ionised gas. Most notable of our work is that, we provide quality of the fit to assess reliability of the measurements. The quality assessment can be highly effective for finding new classes of objects. For example, based on the quality assessment around the Ha and [NII] nebular lines, we found approximately 1% of the SDSS spectra which classified as galaxies by the SDSS pipeline are in fact type I Seyfert AGN. This paper presents a summary of the recent paper, Oh et al.(2011). The database is publicly available at http://gem.yonsei.ac.kr/ossy/.
Probing the opacity of local Universe GAMA galaxies using attenuation-inclination relations
Authors: Andrae Ellen , Tuffs Richard J. , Popescu Cristina C. , Seibert Mark ,   the GAMA Team
Published: August 2012

Even though attenuation by dust strongly attenuates and reddens the UV/optical spectral energy distributions of spiral galaxies, quantifying these effects is challenging, particularly when, as is most often the case, infrared measurements of the absorbed energy are not available. We have initiated a study to model the dependence on inclination of the attenuation of light from galaxies measured in the Galaxy and Mass Assembly (GAMA) survey. We present preliminary results using SDSS galaxies in the phase-I GAMA catalogue, comparing observed attenuation-inclination relations with the predictions of the radiation transfer model of Popescu et al. (2011) to derive a statistical measurement of the mean face-on B-band optical depth of disks τfB in a sample of spiral galaxies complete to the SDSS spectroscopic r-band limit of 17.8 mag.
The unusual multi-wavelength SED of two optical dropout galaxies
Authors: Schaerer Daniel , Boone Frederic , Laporte Nicolas
Published: August 2012

We have used deep optical, near-IR, and IR observations from VLT, Spitzer, Herschel, and LABOCA in strong lensing clusters to study distant galaxies. In searches for optical-dropout galaxies (i.e. for z ≳ 7 candidates) we have found several galaxies with very unusual SEDs characterised by a strong spectral break, presumably indicative of high-z, although the objects are detected even in the Herschel bands between 160 and 500 μm and at 870 μm. The latter indicates, from simple estimates of the bolometric luminosity and from the IR SED, that these ob jects are most likely at z ~ 2–2.5.

The resulting SEDs imply very high IR/UV ratios, indicative of very large attenuation. Despite this, the large spectral break observed between the optical and near-IR data is difficult to understand with currently know spectral templates from galaxies, EROs, SMGs, and others, both empirical and theoretical ones.
The energetics of turbulent molecular gas and star formation
Authors: Boulanger François
Published: August 2012

The role interstellar turbulence plays in regulating star formation is a much debated research topic. In this paper, I take an observational view point in presenting observations of H2 line emission from extragalactic sources. I highlight key results from these observations. (1) H2 line emission is a main cooling channel of molecular gas. It is a tracer of mechanical energy dissipation complementing mass tracers in describing the dynamical state of molecular gas in galaxies. (2) Spectroscopy of warm H2 observations with the Spitzer Space Telescope and the SINFONI spectro-imager at ESO provide evidence of shock excited H2 line emission in galaxies that exemplify the main agents of galaxy evolution. (3) The dissipation of mechanical energy involves a turbulent energy cascade and the cycling of interstellar matter across ISM phases, including the formation of H2 gas from warm atomic gas. (4) In Stephan's Quintet and the radio galaxy 3C326, two sources with a high H2 luminosity to mass ratio (i.e. a high dissipation rate per unit mass), turbulence is observed to quench star formation. In the Antennae merger, star formation is observed to proceed where the turbulent kinetic energy is being dissipated.
Radial variations of the SFHs of dwarf irregular galaxies
Authors: Zhang Hong-Xin , Hunter Deidre A. , Elmegreen Bruce G. , Gao Yu , Schruba Andreas
Published: August 2012

The LITTLE THINGS project† has compiled multi-wavelength data (including VLA hi-line emission maps, GALEX FUV/NUV imagery, UBV, narrow-band Hα, and Spitzer images) for a representative sample of nearby dwarf irregular (dIrr) galaxies. The broadband data are used to constrain the radial variations of the star formation (SF) rate (SFR) averaged over the past 0.1 Gyr, 1 Gyr and a Hubble time, with a complete library of model SF histories (SFHs). The recent SF of more than ~ 80% of the dIrrs in our sample has been concentrated in the inner disk, and the SF in the outer disk has been markedly suppressed. This outside-in shrinking of the star-forming disk leaves a down-bending (double exponential) stellar mass surface density (Σ*) distribution. Our findings in dIrrs are in contrast to the inside-out disk growth scenario suggested for luminous spiral galaxies.
Environmental dependence of SFRs in late-type GAMA galaxies
Authors: Grootes Meiert W. , Tuffs Richard J. , Andrae Ellen , Kelvin Lee S. , Liske Jochen , Madore Barry F. , Popescu Cristina C. , Robotham Aaron S. G. , Seibert Mark , Taylor Edward N. ,   the GAMA Team
Published: August 2012

Present and past gas-fuelling of galaxies is expected to depend upon both the properties of the galaxies themselves, as well as their larger-scale environments. In the case of galaxies in groups the environment, i.e the group mass, can be probed by measuring the velocity dispersion of the group members, as done with the GAMA Galaxy Group catalogue (Robotham et al. 2011), probing the halo mass function all the way to small groups. The gas-fuelling rate of normal late-type galaxies can be traced by the SFR under the assumption of a steady state between gas-fuelling and gas-consumption by SF. We present a method to estimate disk opacities from UV/optical photometric characteristics, calibrated using the radiative transfer model of Popescu et al. (2011), applied to UV-Opt-FIR GAMA/H-ATLAS photometry for a subset of GAMA galaxies. We use the method to extract attenuation corrected SFRs for a large sample of late-type GAMA galaxies, which we use in an initial application to constrain the dependency of star formation/gas-fuelling in late-type galaxies on mass of parent DMH, and compactness of galaxy group.
AKARI/IRC broadband mid-infrared data as an indicator of the Star Formation Rate
Authors: Yuan Fang-Ting , Takeuchi Tsutomu T. , Buat Véronique , Heinis Sébastien , Giovannoli Elodie , Murata Katsuhiro L. , Iglesias-Páramo Jorge , Burgarella Denis
Published: August 2012

With the goal of constructing Star-Formation Rates (SFR) from AKARI Infrared Camera (IRC) data, we analyzed an IR-selected GALEX-SDSS-2MASS-AKARI(IRC & Far-Infrared Surveyor) sample of 153 nearby galaxies. The far-infrared fluxes were obtained from AKARI diffuse maps to correct the underestimation for extended sources raised by PSF photometry. SFRs of these galaxies were derived using the SED fitting program CIGALE. In spite of complicated features contained in these bands, both the S9W and L18W emissions correlate with the SFR of galaxies. The SFR calibrations using S9W and L18W are presented for the first time. These calibrations agree well with previous work based on Spitzer data within the scatter, and should be applicable to dust-rich galaxies.
Cosmic rays and high energy emission from starburst galaxies
Authors: Lacki Brian C. , Thompson Todd A.
Published: August 2012

The nearby starburst galaxies M82 and NGC 253 are now detected in GeV and TeV γ-rays, allowing us to directly study cosmic rays (CRs) in starburst galaxies. Combined with radio observations, the detections constrain the propagation and density of CRs in these starbursts. We discuss the implications for “proton calorimetry”, whether CR protons cool through pion losses before escaping these galaxies. The ratio of γ-ray and radio luminosities constrains how much of the CR electron cooling is due to synchrotron losses. As for leptonic emission, we predict that synchrotron and Inverse Compton emission make up ~1–10% of the unresolved hard X-ray emission from M82, and a few percent or less of the total X-ray emission from starbursts. A detection of these components would inform us of the magnetic field strength and 10 – 100 TeV electron spectrum. We conclude by discussing the prospects for detecting leptonic MeV γ-rays from starbursts and the cosmic γ-ray background.
The challenging SED of AP Librae
Authors: Sanchez David , Giebels Berrie , Fortin Pascal ,   on behalf of the H.E.S.S and Fermi-LAT collaborations
Published: August 2012

Matching the broad-band emission of active galaxies with the predictions of theoretical models can be used to derive constraints on the properties of the emitting region and to probe the physical processes involved. AP Librae is the third low frequency peaked BL Lac (LBL) detected at very high energy (VHE, E>100GeV) by an Atmospheric Cherenkov Telescope; most VHE BL Lacs (34 out of 39) belong to the high-frequency and intermediate-frequency BL Lac classes (HBL and IBL). LBL objects tend to have a higher luminosity with lower peak frequencies than HBLs or IBLs. The characterization of their time-averaged spectral energy distribution is challenging for emission models such as synchrotron self-Compton (SSC) models.
Panchromatic radiation from galaxies as a probe of galaxy formation and evolution
Authors: Rowan-Robinson Michael
Published: August 2012

I review work on modelling the infrared and submillimetre SEDs of galaxies. The underlying physical assumptions are discussed and spherically symmetric, axisymmetric, and 3-dimensional radiative transfer codes are reviewed. Models for galaxies with Spitzer IRS data and for galaxies in the Herschel-Hermes survey are discussed. Searches for high redshift infrared and submillimetre galaxies, the star formation history, the evolution of dust extinction, and constraints from source-counts, are briefly discussed.
Photometric studies of PAH emission from distant infrared galaxies
Authors: Takagi Toshinobu , Matsuhara Hideo , Wada Takehiko , Ohyama Youichi ,   the AKARI extragalactic team
Published: August 2012

Using extensive mid-IR datasets from AKARI, i.e. 9 band photometry covering the wavelength range from 2 μm to 24 μm and the unbiased spectroscopic survey for sources with Sν (9μm)>0.3 mJy, we investigated the PAHs emission features in distant starburst galaxies. PAH-selected galaxies, selected with an extremely red mid-IR colour due to PAHs, are found to have a peculiar rest-frame 11-to-8 μm flux ratio, which is systematically smaller than nearby starburst/AGN spectral templates. This may indicate a systematic difference in the physical condition of the ISM between nearby and distant starburst galaxies.
Charting the evolution of the ages and metallicities of massive galaxies since z = 0.7
Authors: Gallazzi Anna , Bell Eric F. , Zibetti Stefano , Kelson Daniel , Brinchmann Jarle
Published: August 2012

Detailed studies of the stellar populations of intermediate-redshift galaxies can shed light onto the processes responsible for the significant evolution of the massive galaxy population since z < 1. We have undertaken such a study by means of deep rest-frame optical spectroscopy with IMACS on Magellan on a sample of ~80 galaxies selected from CDFS to have stellar masses > 1010M⊙ and redshift 0.65 < z < 0.75. We analyse stellar absorption line strengths and interpret them with a Monte Carlo library of star formation histories to derive constraints on mean stellar ages, metallicities and stellar masses. We present here the first characterization of the stellar mass–metallicity and stellar mass–age relations at z~0.7 and their evolution to the present-day.
High resolution SMA imaging of (ultra)-luminous infrared galaxies
Authors: Tan Qinghua , Gao Yu , Wang Zhong , U Vivian
Published: August 2012

We present preliminary results on Submillimeter Array (SMA) observations of three Luminous Infrared Galaxies (LIRGs) and one infrared Quasi Stellar Object (IR QSO). The galaxies were observed at sub-kpc spatial resolution in lines of CO and 13CO, as well as in the continuum at 1.3mm. The moment maps show that the molecular gas in these galaxies is distributed in rotating disks with velocity gradients ranging from ~30 to 120 km s−1 kpc−1. Combined with archival CO J=3-2 data, the spatial distributions of the CO J=3-2/J=2-1 ratios shows clear variations across the galaxies. The brightness temperature of the overlap region in VV 114 is found to be lower than that in the nuclear region of VV 114E, suggesting that that the bulk of molecular gas in this region is sub-thermalized.
Multi-wavelength probes of distant lensed galaxies
Authors: Serjeant Stephen
Published: August 2012

I summarise recent results on multi-wavelength properties of distant lensed galaxies, with a particular focus on Herschel. Submm surveys have already resulted in a breakthrough discovery of an extremely efficient selection technique for strong gravitational lenses. Benefitting from the gravitational magnification boost, blind mm-wave redshifts have been demonstrated on IRAM, SMA and GBT, and follow-up emission line detections have been made of water, [Oiii], [Cii] and other species, revealing the PDR/XDR/CRDR conditions. I also discuss HST imaging of submm lenses, lensed galaxy reconstruction, the prospects for ALMA and e-Merlin and the effects of differential magnification. Many emission line diagnostics are relatively unaffected by differential magnification, but SED-based estimates of bolometric fractions in lensed infrared galaxies are so unreliable as to be useless, unless a lens mass model is available to correct for differential amplification.
Conference Summary
Authors: Gallagher Jay , Lonsdale Carol , Bruzual Gustavo
Published: August 2012

If galaxies consisted only of stars, and some early-type systems in general and dwarf spheroidal galaxies in particular fit this prescription, then the calculation of the SED in principle is straightforward. The emergent luminosity at any wavelength simply is the sum over all the luminosities of all the stars in the system. This can be calculated, of course provided that one has a complete understanding of stellar populations, which remains a non-trivial issue. Most galaxies, however, also contain an interstellar medium (ISM). The ISM absorbs, scatters and reprocesses the radiation and relativistic particles from sources within galaxies, primarily stars and AGN. That the ISM is neither isotropic nor homogeneous adds to the challenge of how to properly account for its influence on the luminosity emerging from galaxies.
A Spitzer study of interacting luminous and ultra-luminous infrared galaxies
Authors: Leão João Rodrigo S. , Leitherer Claus
Published: August 2012

We conducted a Spitzer Space Telescope survey of 28 Luminous (11 < log (LIR/L⊙) < 12, LIRGs) and Ultra-Luminous Infrared Galaxies (log (LIR/L⊙) > 12, ULIRGs). Many of these galaxies are found in pairs or associations and are powered by either nuclear activity or star-formation (Sanders & Mirabel 1996). Our main goal is to understand the relative importance of starbursts and AGNs in interacting systems. Is the frequency of AGN and starbursts in these interacting galaxies related to their luminosities? What is the importance of the merger stage and the frequency of AGNs? We present our conclusions and diagnostic diagrams based in the observed near infrared lines and compare to studies based solely in optical data.
Systematic errors in ground heat flux estimation and their correction
Authors: Gentine P. , Entekhabi D. , Heusinkveld B.
Published: August 2012

Incoming radiation forcing at the land surface is partitioned among the components of the surface energy balance in varying proportions depending on the time scale of the forcing. Based on a land‐atmosphere analytic continuum model, a numerical land surface model, and field observations we show that high‐frequency fluctuations in incoming radiation (with period less than 6 h, for example, due to intermittent clouds) are preferentially partitioned toward ground heat flux. These higher frequencies are concentrated in the 0–1 cm surface soil layer. Subsequently, measurements even at a few centimeters deep in the soil profile miss part of the surface soil heat flux signal. The attenuation of the high‐frequency soil heat flux spectrum throughout the soil profile leads to systematic errors in both measurements and modeling, which require a very fine sampling near the soil surface (0–1 cm). Calorimetric measurement techniques introduce a systematic error in the form of an artificial band‐pass filter if the temperature probes are not placed at appropriate depths. In addition, the temporal calculation of the change in the heat storage term of the calorimetric method can further distort the reconstruction of the surface soil heat flux signal. A correction methodology is introduced which provides practical application as well as insights into the estimation of surface soil heat flux and the closure of surface energy balance based on field measurements.
Distributed assimilation of satellite‐based snow extent for improving simulated streamflow in mountainous, dense forests: An example over the DMIP2 western basins
Authors: Yatheendradas Soni , Lidard Christa D. Peters , Koren Victor , Cosgrove Brian A. , De Goncalves Luis G. G. , Smith Michael , Geiger Jim , Cui Zhengtao , Borak Jordan , Kumar Sujay V. , Toll David L. , Riggs George , Mizukami Naoki
Published: August 2012

Snow cover area affects snowmelt, soil moisture, evapotranspiration, and ultimately streamflow. For the Distributed Model Intercomparison Project – Phase 2 Western basins, we assimilate satellite‐based fractional snow cover area (fSCA) from the Moderate Resolution Imaging Spectroradiometer, or MODIS, into the National Weather Service (NWS) SNOW‐17 model. This model is coupled with the NWS Sacramento Heat Transfer (SAC‐HT) model inside the National Aeronautics and Space Administration's (NASA) Land Information System. SNOW‐17 computes fSCA from snow water equivalent (SWE) values using an areal depletion curve. Using a direct insertion, we assimilate fSCAs in two fully distributed ways: (1) we update the curve by attempting SWE preservation, and (2) we reconstruct SWEs using the curve. The preceding are refinements of an existing simple, conceptually guided NWS algorithm. Satellite fSCA over dense forests inadequately accounts for below‐canopy snow, degrading simulated streamflow upon assimilation during snowmelt. Accordingly, we implement a below‐canopy allowance during assimilation. This simplistic allowance and direct insertion are found to be inadequate for improving calibrated results, still degrading them as mentioned above. However, for streamflow volume for the uncalibrated runs, we obtain: (1) substantial to major improvements (64–81%) as a percentage of the control run residuals (or distance from observations), and (2) minor improvements (16–22%) as a percentage of observed values. We highlight the need for detailed representations of canopy‐snow optical radiative transfer processes in mountainous, dense forest regions if assimilation‐based improvements are to be seen in calibrated runs over these areas.
Time scaling of the electron flux increase at GEO: The local energy diffusion model vs observations
Authors: Balikhin M. A. , Gedalin M. , Reeves G. D. , Boynton R. J. , Billings S. A.
Published: August 2012

The characteristic time scaling of the electron flux evolution at geosynchronous orbit (GEO), resulting from the quasilinear wave‐particle interaction, is investigated. The upper limit of the electron flux increase rate, due to the interaction with waves, is deduced from the energy diffusion equation (EDE). Such a time scaling allows for a comparison with experimentally measured fluxes of energetic electrons at GEO. It is shown that the analytically deduced time scaling is too slow to explain the observed increase in fluxes. It is concluded that radial diffusion plays the most significant role in the build up of the energetic electrons population at GEO. However, this conclusion is only justified if the seed population energies are very low.
Analysis of cloud‐resolving simulations of a tropical mesoscale convective system observed during TWP‐ICE: Vertical fluxes and draft properties in convective and stratiform regions
Authors: Mrowiec Agnieszka A. , Rio Catherine , Fridlind Ann M. , Ackerman Andrew S. , Del Genio Anthony D. , Pauluis Olivier M. , Varble Adam C. , Fan Jiwen
Published: August 2012

We analyze three cloud‐resolving model simulations of a strong convective event observed during the TWP‐ICE campaign, differing in dynamical core, microphysical scheme or both. Based on simulated and observed radar reflectivity, simulations roughly reproduce observed convective and stratiform precipitating areas. To identify the characteristics of convective and stratiform drafts that are difficult to observe but relevant to climate model parameterization, independent vertical wind speed thresholds are calculated to capture 90% of total convective and stratiform updraft and downdraft mass fluxes. Convective updrafts are fairly consistent across simulations (likely owing to fixed large‐scale forcings and surface conditions), except that hydrometeor loadings differ substantially. Convective downdraft and stratiform updraft and downdraft mass fluxes vary notably below the melting level, but share similar vertically uniform draft velocities despite differing hydrometeor loadings. All identified convective and stratiform downdrafts contain precipitation below ∼10 km and nearly all updrafts are cloudy above the melting level. Cold pool properties diverge substantially in a manner that is consistent with convective downdraft mass flux differences below the melting level. Despite differences in hydrometeor loadings and cold pool properties, convective updraft and downdraft mass fluxes are linearly correlated with convective area, the ratio of ice in downdrafts to that in updrafts is ∼0.5 independent of species, and the ratio of downdraft to updraft mass flux is ∼0.5–0.6, which may represent a minimum evaporation efficiency under moist conditions. Hydrometeor loading in stratiform regions is found to be a fraction of hydrometeor loading in convective regions that ranges from ∼10% (graupel) to ∼90% (cloud ice). These findings may lead to improved convection parameterizations.
Dissipation at tidal and seismic frequencies in a melt‐free Moon
Authors: Nimmo F. , Faul U. H. , Garnero E. J.
Published: August 2012

We calculate viscoelastic dissipation in the Moon using a rheological (extended Burgers) model based on laboratory deformation of melt‐free polycrystalline olivine. Lunar temperature structures are calculated assuming steady state conduction with variable internal heat production and core heat flux. Successful models can reproduce the dissipation factor (Q) measured at both tidal and seismic frequencies, and the tidal Love numbers h2 and k2, without requiring any mantle melting. However, the frequency‐dependence of our modelQat tidal periods has the opposite sign to that observed. Using the apparently unrelaxed nature of the core‐mantle boundary (CMB), the best fit models require mantle grain sizes of ∼1 cm and CMB temperatures of ≈1700 K. If melt or volatiles are present, the lunar temperature structure must be colder than our melt‐free models. We estimate a present‐day mantle heat production rate of 9–10 nWm−3, suggesting that roughly half of the Moon's radiogenic elements are in the crust.
The neurobiology of overeating
Authors: Lee Natalia M , Carter Adrian , Owen Neville , Hall Wayne D
Published: August 2012

Is overeating a neurological disorder like drug or alcohol addiction? Recent advances in neuroscience suggest it might be, which could have profound consequences for the treatment of obese people and public health policies to address the growing epidemic of obesity.
Integration in action
Authors: Green Sara , Wolkenhauer Olaf
Published: August 2012

The workshop on ‘Integration in Biology and Biomedicine’ was held in May 2012 at the University of Sydney. It brought together scientists and philosophers to discuss the need for, and practice of, integration in the life sciences.
Phage display libraries of differently sized bicyclic peptides
Authors: Rebollo Inmaculada Rentero , Angelini Alessandro , Heinis Christian
Published: August 2012

Loop length variability in bicyclic peptide libraries increased the diversity of the motifs found in affinity selections towards the tumor-associated protease uPA.
X-ray bang-time and fusion reaction history at picosecond resolution using RadOptic detection
Authors: Vernon S. P. , Lowry M. E. , Baker K. L. , Bennett C. V. , Celeste J. R. , Cerjan C. , Haynes S. , Hernandez V. J. , Hsing W. W. , LaCaille G. A. , London R. A. , Moran B. , von Wittenau A. Schach , Steele P. T. , Stewart R. E.
Published: August 2012

We report recent progress in the development of RadOptic detectors, radiation to optical converters, that rely upon x-ray absorption induced modulation of the optical refractive index of a semiconductor sensor medium to amplitude modulate an optical probe beam. The sensor temporal response is determined by the dynamics of the electron-hole pair creation and subsequent relaxation in the sensor medium. Response times of a few ps have been demonstrated in a series of experiments conducted at the LLNL Jupiter Laser Facility (JLF). This technology will enable x-ray bang-time and fusion burn-history measurements with ∼ ps resolution.
Improvements to the calibration of the MST Thomson scattering diagnostic
Authors: Parke E. , Den Hartog D. J. , Morton L. A. , Stephens H. D. , Kasten C. P. , Reusch J. A. , Harris W. H. , Borchardt M. T. , Falkowski A. F. , Hurst N. C. , Plunkett A. , Goglio J.
Published: August 2012

Calibration of the Madison Symmetric Torus Thomson scattering system has been refined to improve temperature fluctuation measurements. Multiple avalanche photodiodes have been directly calibrated for use as reference detectors during calibration, improving accuracy and ease of use. From the absolute calibration we calculate corrections to the gain for variation in detector operating temperature. We also measure the spatial uniformity of detector responsivity for several photodiodes, and present a method of accounting for non-uniformity in the calibration process. Finally, the gain and noise enhancement are measured at multiple wavelengths to improve temperature and uncertainty measurements.
Design and fabrication of a multi-purpose soft x-ray array diagnostic system for KSTAR
Authors: Lee Seung Hun , Chai Kil Byoung , Jang Siwon , Ko Won-Ha , Kim Junghee , Seo Dongcheol , Lee Jongha , Bogatu I. N. , Kim Jin-Soo , Choe Wonho
Published: August 2012

A multi-purpose soft x-ray array diagnostic system was developed for measuring two-dimensional x-ray emissivity profile, electron temperature, Ar impurity transport, and total radiation power. A remotely controlled filter wheel was designed with three different choices of filters. The electron temperature profile can be determined from the ratio of two channels having different thickness of Be layer, and the Ar impurity concentration transport can be determined from a pair of Ar Ross filters (CaF2 and NaCl thin films). Without any filters, this diagnostic system can also be used as a bolometer.
Modification of ordinary-mode reflectometry system to detect lower-hybrid waves in Alcator C-Mod
Authors: Baek S. G. , Shiraiwa S. , Parker R. R. , Dominguez A. , Kramer G. J. , Marmar E. S.
Published: August 2012

Backscattering experiments to detect lower-hybrid (LH) waves have been performed in Alcator C-Mod, using the two modified channels (60 GHz and 75 GHz) of an ordinary-mode reflectometry system with newly developed spectral recorders that can continuously monitor spectral power at a target frequency. The change in the baseline of the spectral recorder during the LH wave injection is highly correlated to the strength of the X-mode non-thermal electron cyclotron emission. In high density plasmas where an anomalous drop in the lower hybrid current drive efficiency is observed, the observed backscattered signals are expected to be generated near the last closed flux surface, demonstrating the presence of LH waves within the plasma. This experimental technique can be useful in identifying spatially localized LH electric fields in the periphery of high-density plasmas.
High speed vacuum ultraviolet telescope system for edge fluctuation measurement in the large helical device
Authors: Ming T. F. , Ohdachi S. , Sakakibara S. , Suzuki Y.
Published: August 2012

A high speed tangentially viewing vacuum ultraviolet telescope system has been developed in the Large Helical Device (LHD), with the aim of investigating edge MHD activities. The spatial structure of low frequency (∼0.75 kHz) MHD activity with poloidal/toroidal mode numbers of m/n = 1/1 has been measured with this diagnostic.
Design of the polarization multi-pass Thomson scattering system
Authors: Yasuhara R. , Yoshikawa M. , Morimoto M. , Yamada I. , Kawahata K. , Funaba H. , Shima Y. , Kohagura J. , Sakamoto M. , Nakashima Y. , Imai T. , Minami T.
Published: August 2012

A novel configuration of the multi-pass Thomson scattering (TS) system is proposed to improve the time resolution and accuracy of electron temperature measurements by use of a polarization control technique. This configuration can realize a perfect coaxial multi-passing at each pass, and the number of round trips is not limited by the optical configuration. To confirm the feasibility of the new method, we installed this system in the GAMMA 10 plasma system. As a result, the integrated scattering signal of the double-pass configuration is about two times larger than that of the single-pass configuration. These results are in good agreement with the design.
Time-dependent resilience assessment and improvement of urban infrastructure systems
Authors: Ouyang Min , Dueñas-Osorio Leonardo
Published: August 2012

This paper introduces an approach to assess and improve the time-dependent resilience of urban infrastructure systems, where resilience is defined as the systems’ ability to resist various possible hazards, absorb the initial damage from hazards, and recover to normal operation one or multiple times during a time period T. For different values of T and its position relative to current time, there are three forms of resilience: previous resilience, current potential resilience, and future potential resilience. This paper mainly discusses the third form that takes into account the systems’ future evolving processes. Taking the power transmission grid in Harris County, Texas, USA as an example, the time-dependent features of resilience and the effectiveness of some resilience-inspired strategies, including enhancement of situational awareness, management of consumer demand, and integration of distributed generators, are all simulated and discussed. Results show a nonlinear nature of resilience as a function of T, which may exhibit a transition from an increasing function to a decreasing function at either a threshold of post-blackout improvement rate, a threshold of load profile with consumer demand management, or a threshold number of integrated distributed generators. These results are further confirmed by studying a typical benchmark system such as the IEEE RTS-96. Such common trends indicate that some resilience strategies may enhance infrastructure system resilience in the short term, but if not managed well, they may compromise practical utility system resilience in the long run.
Coadsorption properties of CO2 and H2O on TiO2 rutile (110): A dispersion-corrected DFT study
Authors: Sorescu Dan C. , Lee Junseok , Al-Saidi Wissam A. , Jordan Kenneth D.
Published: August 2012

Adsorption and reactions of CO2 in the presence of H2O and OH species on the TiO2 rutile (110)-(1×1) surface were investigated using dispersion-corrected density functional theory and scanning tunneling microscopy. The coadsorbed H2O (OH) species slightly increase the CO2 adsorption energies, primarily through formation of hydrogen bonds, and create new binding configurations that are not present on the anhydrous surface. Proton transfer reactions to CO2 with formation of bicarbonate and carbonic acid species were investigated and found to have barriers in the range 6.1–12.8 kcal/mol, with reactions involving participation of two or more water molecules or OH groups having lower barriers than reactions involving a single adsorbed water molecule or OH group. The reactions to form the most stable adsorbed formate and bicarbonate species are exothermic relative to the unreacted adsorbed CO2 and H2O (OH) species, with formation of the bicarbonate species being favored. These results are consistent with single crystal measurements which have identified formation of bicarbonate-type species following coadsorption of CO2 and water on rutile (110).
Liquid injection in confined co-flow: Application to portal vein embolization by glue injection
Authors: Sandulache M.-C. , Paullier P. , Bouzerar R. , Yzet T. , Balédent O. , Salsac A.-V.
Published: August 2012

Drop formation in liquid-liquid systems has received considerable attention over the last century owing to its many industrial applications. More recent applications may be found in the field of endovascular/percutaneous treatments. The present study focuses on portal vein embolization (PVE), which consists in the blockage of part of the portal trunk though the injection of surgical glue. The short-time injection is dominated by fluid dynamic effects: the influence of polymerization is secondary owing to the presence of ethiodized oil in the injected mixture. If the mechanism of liquid injection is well understood for injections in unconfined fluids at rest, fewer studies have so far considered the case of outer liquids flowing in confined environments. The objective is therefore to conduct a large range parametric study of liquid injections in confined co-flows. An experimental setup has been designed to simulate in vitro the injection in an immiscible liquid flowing in a cylindrical tube. The transition from the dripping to the jetting regimes is found to be independent of confinement, but to depend on the ratio of the inertial forces of the injected liquid to the surface tension, i.e., the Weber number of the inner flow Wei. The confinement, however, has an influence on the drop size in the dripping regime. Its influence diminishes in the first phase of the jetting regime, as the drop size largely decreases. In the fully established jetting regime, the drop size is finally only a function of the ejection tube diameter. To predict the size of the drops in the dripping regime, we have developed a semiempirical model that takes into account the effects of both the tube confinement and outer flow. It will help the interventional radiologists predict the drop size depending on the geometrical and velocimetric conditions at the site of embolization. All these results can then serve as a base to optimize the PVE technique during clinical practice.
Thermal transport in graphene supported on copper
Authors: Chen Liang , Kumar Satish
Published: August 2012

We investigate the thermal transport in isolated single layer graphene (SLG) and SLG supported on Cu substrate using equilibrium molecular dynamics simulations and relaxation time approximation (RTA) method. We observe significant changes in the SLG dispersion curve in low frequency and low wave-vector region due to the interaction with Cu substrate. Several new phonon modes related to out-of-plane vibrations appear at the low frequency and small wave vector regions, but their contribution to graphene thermal conductivity is negligible. The thermal conductivity of graphene decreases by 44% due to the interactions with Cu substrate for high interaction strength parameter in Lennard-Jones potential formulation for graphene-Cu interaction. The phonon mode analysis through the RTA approach shows that the acoustic phonons dominate the thermal transport for both isolated and supported graphenes. The longitudinal acoustic (LA), transverse acoustic (TA), and out-of-plane acoustic (ZA) phonons contribute 654, 330, and 361 W/mK to the lattice thermal conductivity of isolated graphene, respectively. The phonon life time of ZA modes decreases by order of magnitude due to the interactions with Cu substrate and ZA mode contribution to SLG thermal conductivity decreases by 282 W/mK, while the contributions of LA and TA phonons reduce by 77.4 W/mK and 82.9 W/mK, respectively.
Pulsatility role in cylinder flow dynamics at low Reynolds number
Authors: Qamar Adnan , Samtaney Ravi , Bull Joseph L.
Published: August 2012

We present dynamics of pulsatile flow past a stationary cylinder characterized by three non-dimensional parameters: the Reynolds number (Re), non-dimensional amplitude (A) of the pulsatile flow velocity, and Keulegan-Carpenter number (KC = Uo/Dωc). This work is motivated by the development of total artificial lungs (TAL) device, which is envisioned to provide ambulatory support to patients. Results are presented for 0.2 ≤ A ≤ 0.6 and 0.57 ≤ KC ≤ 2 at Re = 5 and 10, which correspond to the operating range of TAL. Two distinct fluid regimes are identified. In both regimes, the size of the separated zone is much greater than the uniform flow case, the onset of separation is function of KC, and the separation vortex collapses rapidly during the last fraction of the pulsatile cycle. The vortex size is independent of KC, but with an exponential dependency on A. In regime I, the separation point remains attached to the cylinder surface. In regime II, the separation point migrates upstream of the cylinder. Two distinct vortex collapse mechanisms are observed. For A < 0.4 and all KC and Re values, collapse occurs on the cylinder surface, whereas for A > 0.4 the separation vortex detaches from the cylinder surface and collapses at a certain distance downstream of the cylinder. The average drag coefficient is found to be independent of A and KC, and depends only on Re. However, for A > 0.4, for a fraction of the pulsatile cycle, the instantaneous drag coefficient is negative indicating a thrust production.
An experimental method to determine the resistance of a vertically aligned carbon nanotube forest in contact with a conductive layer
Authors: Vo T. T. , Poulain C. , Dijon J. , Fournier A. , Chevalier N. , Mariolle D.
Published: August 2012

High density vertically aligned carbon nanotube (VACNT) forests are considered as a promising conductive material for many applications (interconnects in microelectronics or contact material layer in sliding contact applications). It is thus crucial to characterize the electrical resistance of these forests, especially in contact with the inherent top/bottom conductive substrates. This paper aims to develop an original method to determine the contribution of the different terms in this electrical resistance, which is measured with a tipless atomic force microscope used in high accuracy “force mode.” VACNT stacks with different heights on AlCu substrate with or without Au/Pd top coating are studied. The electrical contact area between the probe tip and the forest is considered to be equivalent to the classical electrical contact area between a tip and a rough surface. With this assumption, the scattering resistance of a mono-wall CNT is 14.6 kΩ μm−1, the top/bottom contact resistance is, respectively, 265 kΩ/385 kΩ. The bottom resistance divided in half is obtained by an interface substrate/CNT catalyst treatment. The same assumption leads to an effective compressive modulus of 175 MPa. These results are consistent with the values published by other authors. The proposed method is effective to optimise the CNT interface contact resistance before integration in a more complex functional structure.
Particle dynamics simulations of Turing patterns
Authors: Dziekan P. , Lemarchand A. , Nowakowski B.
Published: August 2012

The direct simulation Monte Carlo method is used to reproduce Turing patterns at the microscopic level in reaction-diffusion systems. In order to satisfy the basic condition for the development of such a spatial structure, we propose a model involving a solvent, which allows for disparate diffusivities of individual reactive species. One-dimensional structures are simulated in systems of various lengths. Simulation results agree with the macroscopic predictions obtained by integration of the reaction-diffusion equations. Additional effects due to internal fluctuations are observed, such as temporal transitions between structures of different wavelengths in a confined system. For a structure developing behind a propagating wave front, the fluctuations suppress the induction period and accelerate the formation of the Turing pattern. These results support the ability of reaction-diffusion models to robustly reproduce axial segmentation including the formation of early vertebrae or somites in noisy biological environments.
Stability analysis and control of the flow in a symmetric channel with a sudden expansion
Authors: Fani Andrea , Camarri Simone , Salvetti Maria Vittoria
Published: August 2012

The laminar flow in two-dimensional diffusers may produce either symmetric or nonsymmetric steady solutions, depending on the value of the Reynolds number as compared with some critical value. The stability properties of the flow are studied in the context of linear theory. In this context, a sensitivity analysis of the flow instability is carried out with respect to perturbations that may be produced by a realistic passive control, thus providing qualitative hints and quantitative information for the control design. Following the so-obtained information, a passive control is built by introducing a small cylinder in the flow with the aim of stabilizing the unstable symmetric flow configuration in the diffuser. The effectiveness of this control is finally assessed by direct numerical simulation. It is shown that the introduction of the cylinder, placed following the indications of the linear sensitivity analysis in the stable asymmetric flow configuration, allows a steady completely symmetric or less asymmetric flow to be recovered. The flow transient between the uncontrolled asymmetric solution and the symmetric controlled one is analyzed in terms of streamlines and vorticity evolution; the effects of the cylinder introduction on flow dissipation are also assessed.
Identification of errors in the electron density measurements of a tangential interferometer/polarimeter system during a tokamak discharge
Authors: Arakawa H. , Kawano Y. , Itami K.
Published: August 2012

A new method for the comparative verification of electron density measurements obtained with a tangential interferometer and a polarimeter during a discharge is proposed. The possible errors associated with the interferometer and polarimeter are classified by the time required for their identification. Based on the characteristics of the errors, the fringe shift error of the interferometer and the low-frequency noise of the polarimeter were identified and corrected for the JT-60U tangential interferometer/polarimeter system.