bluuebunny/crossref_metadata_2025 huggingface dataset:
Holocene fire occurrence and alluvial responses at the leading edge of pinyon–juniper migration in the Northern Great Basin, USA
Authors: Weppner Kerrie N. , Pierce Jennifer L. , Betancourt Julio L.
Published: July 2013

Fire and vegetation records at the City of Rocks National Reserve (CIRO), south-central Idaho, display the interaction of changing climate, fire and vegetation along the migrating front of single-leaf pinyon (Pinus monophylla) and Utah juniper (Juniperus osteosperma). Radiocarbon dating of alluvial charcoal reconstructed local fire occurrence and geomorphic response, and fossil woodrat (Neotoma) middens revealed pinyon and juniper arrivals. Fire peaks occurred ~ 10,700–9500, 7200–6700, 2400–2000, 850–700, and 550–400 cal yr BP, whereas ~ 9500–7200, 6700–4700 and ~ 1500–1000 cal yr BP are fire-free. Wetter climates and denser vegetation fueled episodic fires and debris flows during the early and late Holocene, whereas drier climates and reduced vegetation caused frequent sheetflooding during the mid-Holocene. Increased fires during the wetter and more variable late Holocene suggest variable climate and adequate fuels augment fires at CIRO. Utah juniper and single-leaf pinyon colonized CIRO by 3800 and 2800 cal yr BP, respectively, though pinyon did not expand broadly until ~ 700 cal yr BP. Increased fire-related deposition coincided with regional droughts and pinyon infilling ~ 850–700 and 550–400 cal yr BP. Early and late Holocene vegetation change probably played a major role in accelerated fire activity, which may be sustained into the future due to pinyon–juniper densification and cheatgrass invasion.
Tame kernels and second regulators of number fields and their subfields
Authors: Browkin Jerzy , Gangl Herbert
Published: July 2013

Assuming a version of the Lichtenbaum conjecture, we apply Brauer-Kuroda relations between the Dedekind zeta function of a number field and the zeta function of some of its subfields to prove formulas relating the order of the tame kernel of a number fieldFwith the orders of the tame kernels of some of its subfields. The details are given for fieldsFwhich are Galois over ℚ with Galois group the group ℤ/2 × ℤ/2, the dihedral groupD2p;pan odd prime, or the alternating groupA4. We include numerical results illustrating these formulas.
Different Paths to the Modern State in Europe: The Interaction Between Warfare, Economic Structure, and Political Regime
Authors: KARAMAN K. KIVANÇ , PAMUK ŞEVKET
Published: July 2013

Theoretical work on taxation and state-building borrows heavily from early modern European experience. While a number of European states increased centralized tax revenues during this period, for others revenues stagnated or even declined and these variations have motivated alternative arguments for the determinants of fiscal and state capacity. This study reviews the arguments concerning the three determinants that have received most attention, namely warfare, economic structure, and political regime, and tests them by making use of a new and comprehensive tax revenue dataset. Our main finding is that these three determinants worked in interaction with each other. Specifically, when under pressure of war, it was representative regimes in more urbanized-commercial economies and authoritarian regimes in more rural-agrarian economies that tended to better aggregate domestic interests towards state-building.
Priority Primate Areas in Tanzania
Authors: Davenport Tim R.B. , Nowak Katarzyna , Perkin Andrew
Published: July 2013

Priority Primate Areas are identified in Tanzania, mainland Africa's most important country for conservation of primates, on the basis of occupancy by globally rare, Red-Listed and range-restricted primate species and subspecies. We provide a comprehensive list and regional assessment of Tanzania's primate taxa, using IUCN Red List criteria, as well as the first national inventory of primates for 62 sites. The Priority Primate Areas, encompassing 102,513 km2, include nine national parks, one conservation area, seven game reserves, six nature reserves, 34 forest reserves and five areas with no official protection status. Primate species were evaluated and ranked on the basis of irreplaceability and vulnerability, using a combination of established and original criteria, resulting in a primate Taxon Conservation Score. Sites were ranked on the basis of summed primate scores. The majority (71%) of Priority Primate Areas are also Important Bird Areas (IBAs), or part of an IBA. Critical subsets of sites were derived through complementarity analyses. Adequate protection of just nine sites, including six national parks (Kilimanjaro, Kitulo, Mahale, Saadani, Udzungwa and Jozani-Chwaka Bay), one nature reserve (Kilombero) and two forest reserves (Minziro and Mgambo), totalling 8,679 km2, would protect all 27 of Tanzania's primate species. The addition of three forest reserves (Rondo, Kilulu Hill and Ngezi) and two game reserves (Grumeti and Biharamulo), results in a list of 14 Priority Primate Areas covering 10,561 km2 (1.1% of Tanzania's total land area), whose conservation would ensure the protection of all 43 of Tanzania's species and subspecies of primates.
High throughput sequencing of the Angiostrongylus cantonensis genome: a parasite spreading worldwide
Authors: MORASSUTTI ALESSANDRA L. , PERELYGIN ANDREY , DE CARVALHO MARCOS O. , LEMOS LEANDRO NASCIMENTO , PINTO PAULO MARCOS , FRACE MIKE , WILKINS PATRICIA P. , GRAEFF-TEIXEIRA CARLOS , DA SILVA ALEXANDRE J.
Published: July 2013

Angiostrongylus cantonensis is a parasitic nematode of rodents and a leading aetiological agent of eosinophilic meningitis in humans. Definitive diagnosis is difficult, often relying on immunodiagnostic methods which utilize crude antigens. New immunodiagnostic methods based on recombinant proteins are being developed, and ideally these methods would be made available worldwide. Identification of diagnostic targets, as well as studies on the biology of the parasite, are limited by a lack of molecular information on Angiostrongylus spp. available in databases. In this study we present data collected from DNA random high-throughput sequencing together with proteomic analyses and a cDNA walking methodology to identify and obtain the nucleotide or amino acid sequences of unknown immunoreactive proteins. 28 080 putative ORFs were obtained, of which 3371 had homology to other deposited protein sequences. Using the A. cantonensis genomic sequences, 156 putative ORFs, matching peptide sequences obtained from previous proteomic studies, were considered novel, with no homology to existing sequences. Full-length coding sequences of eight antigenic target proteins were obtained. In this study we generated not only the complete nucleotide sequences of the antigenic protein targets but also a large amount of genomic data which may help facilitate future genomic, proteomic, transcriptomic or metabolomic studies on Angiostrongylus.
FACTORS INFLUENCING DECISION MAKING ON THERAPEUTIC INTERVENTIONS
Authors: Lee Sang Moo , Kim Gaeun , Ahn Jeonghoon , Suh Hae Sun , Heo Dae Seog
Published: July 2013

Objectives: The aim of this study was to explore factors that influenced decision making in the assessment of new health technology in Korea.

Methods: We analyzed the decision-making results of the Committee for New Health Technology Assessment (CnHTA) on fifty-three new nondrug health technologies in Korea from July 2007 to December 2010. The scope of the committee was mainly limited to safety and efficacy/effectiveness, and every decision was based on a systematic review of the literature. The committee was composed of healthcare professionals, policy makers, lawyers, and representatives from nongovernmental organizations. Decisions made on therapeutic interventions were included, while those on diagnostic procedures were excluded.

Results: Factors that positively influenced decisions were lower complication rate than existing technology, similar or greater effectiveness compared with existing technology, ability to save critical organs, absence of alternative intervention, decreased invasiveness, expansion of patient's set of choices, and similarity to the mechanism of existing technology. Factors that negatively influenced decisions were higher complication rates than existing technology, lower effectiveness than comparable technology, low levels of evidence, unknown mechanisms of intervention, inconsistency, lack of long-term outcomes, lack of comparative data, nonstandardized technology, heterogeneity between control and treatment, excessively diverse indications, and nongeneralizability.

Conclusions: This qualitative analysis of past decision-making results provided us with clues on the values that decision makers on the Korean CnHTA considered in terms of safety and effectiveness. These findings will help us develop appraisal guidelines and enhance the objectivity of decision-making processes in Korea.
HYPERBARIC OXYGEN THERAPY FOR DIABETIC ULCERS: SYSTEMATIC REVIEW AND META-ANALYSIS
Authors: O'Reilly Daria , Pasricha Anjori , Campbell Kaitryn , Burke Natasha , Assasi Nazila , Bowen James M. , Tarride Jean-Eric , Goeree Ron
Published: July 2013

Objectives: Approximately 10–15 percent of individuals with diabetes mellitus develop foot ulcers, which precede 85 percent of amputations. Increased oxygen, through the use of hyperbaric oxygen therapy (HBOT), has been suggested to encourage ulcer healing thus reducing the risk of amputation. The objective of this systematic review is to evaluate the efficacy of systemic HBOT for nonhealing ulcers of the lower limb in diabetes patients.

Methods: A systematic search, using controlled and keyword terms focusing on “HBOT” and “lower limb diabetic ulcers,” was conducted. Databases searched included Medline, EMBASE, CINAHL, PubMed, Wiley's Cochrane Library, and Biosis. Randomized controlled trials (RCTs) and observational studies were included. Pooled estimates of outcomes were determined when appropriate.

Results: Of the 654 citations identified, 157 articles underwent full-text review. Data were abstracted from twelve publications (six RCTs and six comparative observational studies). Pooled analysis of the RCT and observational data showed that treatment with HBOT reduced the risk of major amputation by 60 percent (p = .29) and 61 percent (p = .003) compared with standard wound care, respectively. The RCT data revealed that the relative risk of having an unhealed wound following HBOT was 0.54 (p = .10) and 0.24 (p < .0001) based on observational data.

Conclusions: Due to the limited RCT evidence, it is not possible to conclusively establish the benefits and harms of treating diabetic lower limb ulcers with HBOT. No significant effects on amputation rates were found in the RCT evidence and in the high quality studies, no difference was found.
Homotopy commutativity in p-localized gauge groups
Authors: Kishimoto D. , Kono A. , Theriault S.
Published: July 2013

Let G be a simple, compact Lie group and let $\mathcal{G}_k(G)$ be the gauge group of the principal G-bundle over S4 with second Chern class k. McGibbon classified the groups G that are homotopy commutative when localized at a prime p. We show that in many cases the homotopy commutativity of G, or its failure, determines that of $\mathcal{G}_k(G)$.
On semiclassical states of a nonlinear Dirac equation
Authors: Ding Y. H. , Lee C. , Ruf B.
Published: July 2013

We study the semiclassical limit of the least energy solutions to the nonlinear Dirac equation

for x ∈ ℝ3. We prove that the equation has least energy solutions for all ħ > 0 small, and, in addition, that the solutions converge in a certain sense to the least energy solution of the associated limit problem as ħ → 0.
Norm resolvent convergence of singularly scaled Schrödinger operators and δ′-potentials
Authors: Golovaty Yu. D. , Hryniv R. O.
Published: July 2013

For a real-valued function V of the Faddeev–Marchenko class, we prove the norm-resolvent convergence, as ε → 0, of a family Sε of one-dimensional Schrödinger operators on the line of the form

Under certain conditions, the functions ε−2V (x/ε) converge in the sense of distributions as ε → 0 to δ′ (x), and then the limit S0 of Sε may be considered as a ‘physically motivated’ interpretation of the one-dimensional Schrödinger operator with potential δ′.
INTEREST RATE RULES AND EQUILIBRIUM STABILITY UNDER DEEP HABITS
Authors: Zubairy Sarah
Published: July 2013

This paper studies the determinacy of equilibrium in a new Keynesian model with deep habits under different interest rate rules. The main finding is that an interest rate rule satisfying the Taylor principle is no longer a sufficient condition to guarantee determinacy. Including interest rate smoothing and a response to output deviations from steady state significantly enlarges the regions of determinacy. However, under all the simple interest rate rules considered, determinacy is not guaranteed for a very high degree of deep habits. Deep habits give rise to countercyclical markups, which is in line with empirical evidence and makes them an appealing feature in the study of demand shocks. The countercyclicality of markups also leads to multiple equilibria because of self-fulfilling expectations for a high degree of deep habit formation.
Net returns and risk for cover crop use in Alabama tomato production
Authors: Duzy Leah M. , Kornecki Ted S. , Balkcom Kipling S. , Arriaga Francisco J.
Published: July 2013

Tomato (Solanum lycopersicumL.) producers are faced with uncertain yields and prices, and utilizing a production system that will reduce risk while maintaining yield may keep tomato producers economically sustainable into the future. A conservation tillage production system with high biomass cover crops may be an economically viable alternative for tomato producers in Alabama. The objective of this study was to compare the economics of alternative production systems using different cover crops, such as cereal rye (Secale cerealeL.) and crimson clover (Trifolium incarnatumL.), and different subsoiler shanks for fresh-market tomato production relative to a commonly used plastic mulch system to determine the preferred treatment. Gross revenues and net returns from tomato production using a rye cover crop were higher than tomato production using plastic mulch in 2 of the 4 years. For the clover cover crop, gross revenues and net returns were higher in 1 out of the 4 years. Under tomato prices and weather conditions observed during 2005–2008, the preferred treatment for a risk neutral producer was planting tomatoes into a rye cover crop with a wide shank. For a strongly risk averse producer, all cover crop treatments were preferred to plastic mulch. The use of a cover crop in tomato production has the potential to be an equally profitable, less risky alternative to plastic mulch in Alabama.
The size and mass evolution of the massive galaxies over cosmic time
Authors: Trujillo Ignacio
Published: July 2013

Once understood as the paradigm of passively evolving objects, the discovery that massive galaxies experienced an enormous structural evolution in the last ten billion years has opened an active line of research. The most significant pending question in this field is the following: which mechanism has made galaxies to grow largely in size without altering their stellar populations properties dramatically? The most viable explanation is that massive galaxies have undergone a significant number of minor mergers which have deposited most of their material in the outer regions of the massive galaxies. This scenario, although appealing, is still far from be observationally proved since the number of satellite galaxies surrounding the massive objects appears insufficient at all redshifts. The presence also of a population of nearby massive compact galaxies with mixture stellar properties is another piece of the puzzle that still does not nicely fit within a comprehensive scheme. I will review these and other intriguing properties of the massive galaxies in this contribution.
The Morphologies of Massive Galaxies at 1<z<3 in the CANDELS-UDS Field: Compact Bulges, and the Rise and Fall of Massive Disks
Authors: Bruce V. A. , Dunlop J. S. , Cirasuolo M. , McLure R. J. , Targett T. A. , Bell E. F. , Croton D. J. , Dekel A. , Faber S. M. , Ferguson H. C. , Grogin N. A. , Kocevski D. D. , Koekemoer A. M. , Koo D. C. , Lai K. , Lotz J. M. , McGrath E. J. , Newman J. A. , van der Wel A.
Published: July 2013

We have used high-resolution, HST WFC3/IR, near-infrared imaging to conduct a detailed bulge-disk decomposition of the morphologies of ≃ 200 of the most massive (M* > 1011 M⊙) galaxies at 1 < z < 3 in the CANDELS-UDS field. We find that, while such massive galaxies at low redshift are generally bulge-dominated, at redshifts 1<z<2 they are predominantly mixed bulge+disk systems, and by z > 2 they are mostly disk-dominated. Interestingly, we find that while most of the quiescent galaxies are bulge-dominated, a significant fraction (25–40%) of the most quiescent galaxies, have disk-dominated morphologies. Thus, our results suggest that the physical mechanisms which quench star-formation activity are not simply connected to those responsible for the morphological transformation of massive galaxies.
The extended gas halo of QSO host galaxies
Authors: Falomo R. , Farina E. P. , Decarli R. , Treves A. , Kotilainen J.
Published: July 2013

We investigate the MgII 2800 and CIV 1540 absorption features of the gas in the halo of a foreground QSO through the absorption imprinting on the spectra of a background QSO that is closely aligned with the nearest quasar. We present the results for 13 QSO pairs (0.7 < z < 2.2) that allow us to probe the gas at distances between 60 kpc and 120 kpc from the QSO nucleus. We identify absorption features associated with the foreground QSO in 7 out of 10 systems for MgII, and one out of 3 for CIV (see example in Fig. 1). At variance with the case of inactive and less massive galaxies we find that relatively strong (EW ~ 1 Ang) absorption features are present out to a radius of 100 kpc. This suggests that a large extended halo is associated with massive galaxies.

The comparison of these results with those for inactive (not hosting active black holes) galaxies (see e.g. Chen et al. 2010a) shows that the halo of QSOs is similar to that of inactive galaxies. In the observed sample we do not detect a significant enhancement of the absorption strengths, as it could be expected if the QSO nuclear activity were driven by intense gas accretion onto the black hole. Moreover along the line of sight of the QSO we do not detect any Mg II absorbers of the same strength of the transverse one. These results are in agreement with models that consider a non-isotropic emission of the QSO, which are hosted by massive gaseous halos.
The nature of the 8 o'clock arc using Near-IR IFU spectroscopy with SINFONI
Authors: Shirazi M. , Vegetti S. , Nesvadba N. , Brinchmann J. , Allam S. , Tucker D.
Published: July 2013

We present an analysis of the lensed Lyman Break Galaxy (LBG), the 8 o'clock arc, at redshift 2.735. We reduced Near-IR IFU data from SINFONI on VLT covering λ= 2900 Å to 6500 Å in the rest-frame. From this we recovered the Hβ map and the spatially-resolved Hβ profile which are shown in the right plot in Fig. 1. We can see that Hβ shows different profiles at different spatial pixels and it is composed of multiple components. To study the de-lensed morphology of the galaxy we make use of existing B & H band imaging from the HST. Based on this we constructed a rigorous lens model for the system using the Bayesian grid based lens modeling technique presented by Vegetti & Koopmans (2009, MNRAS, 392, 945). In order to obtain a robust lens model, we first considered the high resolution B band HST image (rest-frame UV, left plot in Fig. 1) and then used this modeling to reconstruct the Hβ line map of the galaxy. We then present the de-lensed Hβ line map, velocity and velocity dispersion maps of this LBG galaxy.
Star Formation & Molecular Gas over Cosmic Time
Authors: Daddi E. , Sargent M. T. , Béthermin M. , Magdis G.
Published: July 2013

Recent observations have revealed the existence of a ‘main sequence’ of star-forming galaxies out to high redshift. While the majority of star-forming galaxies are observed to be close to this relation between star formation rate (SFR) and stellar mass, a smaller subset of the population – so-called ‘starbursts’ – displays specific star-formation rates and star-formation efficiencies that exceed those of normal (main-sequence) galaxies by up to an order of magnitude. A large degree of homogeneity and similarity has been observed for the properties of the population of normal galaxies across a broad redshift range, including a narrow correlation between their CO luminosity (hence gas content) and IR luminosity and an almost invariable IR SED getting warmer with redshift, while starburst galaxies display systematically different properties. This can be used to devise a simple description of the evolution of the star-forming galaxy population since z ~ 2 and, with a higher degree of uncertainty, even further back in time, in a scheme that we dub two star formation mode framework (2-SFM). We show how this can successfully reproduce the shape of the IR luminosity function of galaxies as a function of redshifts, and the IR number counts. Furthermore, we can link the cosmic evolution of the sSFR of main-sequence galaxies to the evolution of the molecular fuel reservoir and to derive estimates of the molecular gas mass functions of star-forming galaxies that are based on their empirically measured gas properties rather than simulations or semi-analytical modelling. We also infer the evolution of the cosmic abundance of molecular gas and briefly discuss its expected observational signature by molecular line emission, the CO luminosity function.
Connection between the Star Formation Rate and the Gamma-Ray Bursts
Authors: Mészáros Attila , Bagoly Zsolt , Balázs Lajos G. , Horváth István
Published: July 2013

It is remarkable that the long gamma-ray bursts, as objects connected with the supernovae - i.e. with the end-stages of massive stars, trace the star formation rate. This connection is discussed in this contribution. The presentation is in essence a recapitulation of the article by Mészáros et al. (2006).
Stacking of Interferometric Data
Authors: Lindroos Lukas , Knudsen Kirsten K.
Published: July 2013

Radio and mm observations play an important role in determining the star formation properties of high redshift galaxies. However, most galaxies at high redshift are too faint to be detected individually at these wavelengths. A way to study this population of galaxies is to use stacking. By averaging the emission of a large number of galaxies detected in optical or near infrared surveys, we can achieve statistical detection.

We investigate methods for stacking data from interferometric surveys. Interferometry poses unique challenges in stacking due to the nature of imaging of this data. We have compared directly stacking the uv data with stacking of the imaged data, the latter being the typically used approach. Using simulated data, we find that uv-stacking may provide around 50% less noise and that image based stacking systematically loses around 10% of the flux.
The emergence of the red sequence at z~2 seen through galaxy clustering in the UKIDSS UDS
Authors: Hartley William G. , Almaini Omar , Mortlock Alice , Conselice Chris ,   the UDS team
Published: July 2013

We use the UKIDSS Ultra-Deep Survey, the deepest degree-scale near-infrared survey to date, to investigate the clustering of star-forming and passive galaxies to z ~ 3.5. Our new measurements include the first determination of the clustering for passive galaxies at z > 2, which we achieve using a cross-correlation technique. We find that passive galaxies are the most strongly clustered, typically hosted by massive dark matter halos with Mhalo > 1013 M⊙ irrespective of redshift or stellar mass. Our findings are consistent with models in which a critical halo mass determines the transition from star-forming to passive galaxies.
The Co-Evolution of Supermassive Black Holes and Galaxies: Observational Constraints
Authors: Zheng Xian Zhong
Published: July 2013

The connection between the growth of supermassive black holes (SMBHs) and the assembly of their host galaxies is termed ‘co-evolution’. Understanding co-evolution is one of the most fundamental issues in modern astrophysics. In this contribution, we review recent progress in addressing how the growth of SMBHs is linked to the properties of their host galaxies in the context of galaxy evolution, from the observational point of view. Although a coherent picture has not yet emerged, multiple pathways of co-evolution appear to be favored with a probable dependence on AGN luminosity and redshift.
The stellar populations in low excitation and high excitation radio galaxies
Authors: Pracy Michael B. , Ching John , Croom Scott , Sadler Elaine M.
Published: July 2013

We have conducted deep optical spectroscopic follow up of a sample of radio galaxies with redshifts z < 0.7. The spectra were used to construct robust sub-samples of low excitation and high excitation AGN and perform stellar population analysis via line indices and spectral fitting. While the high excitation objects have lower luminosity-weighted ages and lower metallicities than the low excitation galaxies, this can be explained by the different stellar mass distributions of the samples. When stellar mass is taken into account the age and metallicity distribution of both populations are consistent with the galaxy population as a whole.
Understanding the growth of massive galaxies via stellar populations
Authors: Ferreras Ignacio
Published: July 2013

The formation and evolution of massive galaxies represent one of the most intriguing open problems in astrophysics. Their underlying stellar populations encode valuable information about their past history. Detailed spectroscopic observations allow us to constrain the star formation histories, revealing a complicated mixture of a strong, early formation process, followed by passive evolution in the cores, along with an extended assembly of the outer regions via minor mergers. In this contributed talk, some recent results are presented from the analysis of samples of massive galaxies both at z ~ 0 and moderate redshift.
Stellar velocity dispersions and emission line properties of SDSS-III/BOSS galaxies
Authors: Thomas D. , Steele O. , Maraston C. , Johansson J. , Beifiori A. , Pforr J. , Strömbäck G. , Tremonti C. A. , Wake D. ,   the BOSS collaboration
Published: July 2013

We perform a spectroscopic analysis of 492,450 galaxy spectra from the first two years of observations of the Sloan Digital Sky Survey-III/Baryonic Oscillation Spectroscopic Survey (BOSS) collaboration. This data set has been released in the ninth SDSS data release, the first public data release of BOSS spectra. We show that the typical signal-to-noise ratio of BOSS spectra is sufficient to measure stellar velocity dispersion and emission line fluxes for individual objects. The typical velocity dispersion of a BOSS galaxy is 240 km/s, with an accuracy of better than 30 per cent for 93 per cent of BOSS galaxies. The distribution in velocity dispersion is redshift independent between redshifts 0.15 and 0.7, which reflects the survey design targeting massive galaxies with an approximately uniform mass distribution in this redshift interval. The majority of BOSS galaxies lack detectable emission lines. We analyse the emission line properties and present diagnostic diagrams using the emission lines [OII], Hβ, [OIII], Halpha, and [NII] (detected in about 4 per cent of the galaxies). We show that the emission line properties are strongly redshift dependent and that there is a clear correlation between observed frame colours and emission line properties. Within in the low-z sample around 0.15 < z < 0.3, half of the emission-line galaxies have LINER-like emission line ratios, followed by Seyfert-AGN dominated spectra, and only a small fraction of a few per cent are purely star forming galaxies. AGN and LINER-like objects, instead, are less prevalent in the high-z sample around 0.4 < z < 0.7, where more than half of the emission line objects are star forming. This is a pure selection effect caused by the non-detection of weak Hβ emission lines in the BOSS spectra. Finally, we show that star forming, AGN and emission line free galaxies are well separated in the g - r vs r - i target selection diagram.
Evolution of the most massive galaxies to z ~ 0.6
Authors: Chen Yanmei
Published: July 2013

We develop a new method to estimate galaxy physical parameters, such as stellar masses, or star formation histories. This method is based on principal component analysis (PCA), using the information in rest-frame 3700-5500Å spectral region. The derived physical parameters are then applied to study the evolution of the most massive galaxies from z ~ 0.6 to the local Universe, especially on how radio AGN influence the recent star formation histories of host galaxies.
A phenomenological approach to the evolution of galaxies
Authors: Lilly Simon J. , Peng Yingjie , Carollo Marcella , Renzini Alvio
Published: July 2013

Increasingly good statistical data on the galaxy population at high and low redshift enable the development of new phenomenological approaches to galaxy evolution based on application of the simplest continuity equations. This has given new insights into the different ways in which star-formation in galaxies is quenched, the role of merging in the population, and in to the control of star-formation in star-forming galaxies and the links with chemical evolution. The continuity approach provides a self-consistent view of the evolving population and exposes linkages between different aspects of galaxy evolution.
Evolution in cluster cores since z ~ 1
Authors: Burke Claire , Collins Chris , Stott John , Hilton Matt
Published: July 2013

A large fraction of the stellar mass in galaxy clusters is thought to be contained in the diffuse low surface brightness intracluster light (ICL). Being bound to the gravitational potential of the cluster rather than any individual galaxy, the ICL contains much information about the evolution of its host cluster and the interactions between the galaxies within. However due its low surface brightness it is notoriously difficult to study. We present the first detection and measurement of the flux contained in the ICL at z ~ 1. We find that the fraction of the total cluster light contained in the ICL may have increased by factors of 2–4 since z ~ 1, in contrast to recent findings for the lack of mass and scale size evolution found for brightest cluster galaxies. Our results suggest that late time build-up in cluster cores may occur more through stripping than merging and we discuss the implications of our results for hierarchical simulations.
Evolution of the Fundamental Plane for early–type galaxies up to z = 1.2
Authors: Lorenzo M. Fernández , Cepa J. , Bongiovanni A. , García A. M. Pérez , Ederoclite A. , Lara-López M. A. , Pović M. , Sánchez-Portal M.
Published: July 2013

We studied the evolution of the Fundamental Plane in B– and g–bands, for two samples of early–type galaxies at 0.2 < z < 0.35 and 0.35 < z < 1.2. We found a difference in the intercept that can be interpreted as galaxies at < z > ~0.7 being 0.68 and 0.52 mag brighter in the B– and g–band respectively, than their local counterparts. From the study of the Kormendy relation, we found the existence of a population of very bright (−21.5 > Mg > −22.5) and compact (Re < 2 kpc) galaxies of which only a small fraction of 0.4% exists at z = 0, and that would be responsible for the apparent evolution in the Kormendy relation (Fernández Lorenzo et al. 2011). These compact objects would have evolved mainly in size by the action of “dry” minor mergers.

We checked the effect of these bright and compact objects in the FP by comparing the galaxies with −21.5 > Mg > −22.5 of our high–redshift sample and the SDSS early–type galaxies of Bernardi et al. (2003) in Fig. 1. The previous evolution found in the FP seems to be caused mainly by these galaxies, which have virtually disappeared at z = 0.
Stellar Populations in the Most Luminous Obscured Quasars at z > 0.5
Authors: Liu Xin
Published: July 2013

There is evidence that the growth of stellar populations and supermassive black holes (SMBHs) are coupled across cosmic time: the redshift evolution of star formation rate and quasar number density are similar; SMBH masses in local inactive galaxies are correlated with the velocity dispersion of their stellar bulges. Models predict that SMBHs predominantly grow in brief quasar phases accompanied by starbursts, but on-going starbursts in luminous quasars have been difficult to quantify. There have been extensive photometric studies of quasar host galaxies. However, spectroscopic studies that provide crucial information on stellar populations such as age and velocity dispersion are scarce, especially at the highest luminosities, where the stars are vastly outshone by the quasar.
The Age-Redshift Relation For LRGs
Authors: Liu Gaochao , Lu Youjun , Chen Xuelei , Zhao Yongheng , Du Wei , Meng Xianmin
Published: July 2013

The relative age of galaxies at different redshifts can be used to infer the Hubble parameter and put constraints on cosmological models. We select 23,883 quiescent luminous red galaxies (LRGs) from the SDSS DR7, dividing them into four sub-samples according to their velocity dispersions. Each sub-sample was further divided into 12 redshift bins. The spectra of the LRGs in each redshift and velocity bin were co-added. Adopting the GalexEV/SteLib model, we estimate the mean ages of the LRGs from these combined spectra by the full-spectrum fitting method and find it is consistent with the well known “downsizing” formation of galaxies. Based on the age–redshift relation, we further estimate the Hubble parameter.
Discriminating Quasars from Stars Based on SDSS and UKIDSS Databases
Authors: Ma He , Zhang Yanxia , Zhao Yongheng , Zhang Bo
Published: July 2013

In this work, two different algorithms: Linear Discriminant Analysis (LDA) and Support Vector Machines (SVMs) are combined for the classification of unresolved sources from SDSS DR8 and UKIDSS DR8. The experimental result shows that this joint approach is effective for our case.
Dry minor mergers and the size evolution of high-z compact massive early-type galaxies
Authors: Oogi Taira , Habe Asao
Published: July 2013

Recent observations show evidence that high-z (z ~ 2 − 3) early-type galaxies (ETGs) are more compact than those with comparable mass at z ~ 0 (e.g. Trujillo et al. 2007; Buitrago et al. 2008). Such a size evolution is most likely explained by the ‘dry merger scenario’. However, previous studies based on this scenario are not able to consistently explain both the properties of the high-z compact massive ETGs and the local ETGs (Nipoti et al. 2009). We investigate the effect of multiple sequential minor mergers on the size evolution of the compact massive ETGs.
Studying Luminous Red Galaxies to probe H(z) at high redshift
Authors: Ratsimbazafy A. , Cress C. , Crawford S. ,   SCALPEL team
Published: July 2013

Luminous Red Galaxies (LRGs) have old, red stellar populations often interpreted as evidence of a formation scenario in which these galaxies form in a single intense burst of star formation at high redshift. By measuring the average age of LRGs at two different redshifts, one can potentially measure the redshift interval corresponding to a time interval and thus measure the Hubble parameter H(z) ≈ −(1 + z)−1 Δ z/Δt (as in Jimenez & Loeb). The goal of this project is to measure directly the expansion rate of the universe at the redshift range 0.1 < z < 1.0 within 3% precision. We explore the age-dating of Sloan Digital Sky Survey LRGs using the stellar population models of Lick absorption line indices after stacking spectra in redshift bins to increase the signal-to-noise. We also use the method of full spectral fitting to measure the ages of LRGs observed with the Southern Africa Large Telescope (SALT).
The hierarchical evolution of Brightest Cluster Galaxies: red galaxies in a young universe
Authors: Tonini Chiara
Published: July 2013

We investigate the evolution of Brightest Cluster Galaxies (BCGs) from redshift z ~ 1.6 to z = 0. We upgrade the hierarchical semi-analytic model of Croton et al. (2006) with a new spectro-photometric model that produces realistic galaxy spectra, making use of the Maraston (2005) stellar populations and a new recipe for the dust extinction. We compare the model predictions of the K-band luminosity evolution and the J-K, V-I and I-K colour evolution with a series of datasets, including Collins et al. (Nature, 2009) who argued that semi-analytic models based on the Millennium simulation cannot reproduce the red colours and high luminosity of BCGs at z > 1. We show instead that the model is well in range of the observed luminosity and correctly reproduces the colour evolution of BCGs in the whole redshift range up to z ~ 1.6. We argue that the success of the semi-analytic model is in large part due to the implementation of a more sophisticated spectro-photometric model. An analysis of the model BCGs shows an increase in mass by a factor 2-3 since z ~ 1, and star formation activity down to low redshifts. While the consensus regarding BCGs is that they are passively evolving, we argue that this conclusion is affected by the degeneracy between star formation history and stellar population models used in SED-fitting, and by the inefficacy of toy-models of passive evolution to capture the complexity of real galaxies, especially those with rich merger histories like BCGs. Following this argument, we also show that in the semi-analytic model, the BCGs show a realistic mix of stellar populations, and that these stellar populations are mostly old. In addition, the age-redshift relation of the model BCGs follows that of the Universe, meaning that given their merger history and star formation history, the ageing of BCGs is always dominated by the ageing of their stellar populations. In a ΛCDM Universe, we define such evolution as ‘passive in the hierarchical sense’.
A Possible Stream of Accreted Globular Clusters in M 31
Authors: Yuan H.-B.
Published: July 2013

Globular clusters (GCs) are excellent tracers for the formation, assembly and evolutionary history of their host galaxies. However, their origin and their role in galaxy evolution are still unclear. There are accumulating evidences that a significant fraction of GCs in massive galaxies (e.g., M 31) are accreted during their assembly history (e.g., Mackey et al. 2010). In this contribution, we report the discovery of a possible stream of accreted GCs in M 31 using data from the literature. Unlike previous substructures of GCs identified as clumps in the phase and metallicity space (Ashman, Keith & Christina 1993), the members of this stream are widely spread but tightly correlated in the position-velocity space (see Fig. 1). The tight correlation suggests that they possibly follow very similar orbits. A number of stellar streams have been discovered in the outer halo of M 31 (e.g., Ibata et al. 2001; McConnachie et al. 2009), one of which may be physically associated with the GC stream. If the association is established, it will not only provide a key evidence for accretion origins of some GCs in M 31, but also place a strong constraint on the mass distribution of M 31.
Supermassive black holes: Coevolution (or not) of black holes and host galaxies
Authors: Kormendy John
Published: July 2013

Supermassive black holes (BHs) have been found in 75 galaxies by observing spatially resolved dynamics. The Hubble Space Telescope (HST) revolutionized BH work by advancing the subject from its ‘proof of concept’ phase into quantitative studies of BH demographics. Most influential was the discovery of a tight correlation between BH masses M• and the velocity dispersions σ of stars in the host galaxy bulge components at radii where the stars mostly feel each other and not the BH. Together with correlations between M• and bulge luminosity, with the ‘missing light’ that defines galaxy cores, and with numbers of globular clusters, this has led to the conclusion that BHs and bulges coevolve by regulating each other's growth. This simple picture with one set of correlations for all galaxies dominated BH work in the past decade.

New results are now replacing the above, simple story with a richer and more plausible picture in which BHs correlate differently with different kinds of galaxy components. BHs with masses of 105—106M⊙ live in some bulgeless galaxies. So classical (merger-built) bulges are not necessary equipment for BH formation. On the other hand, while they live in galaxy disks, BHs do not correlate with galaxy disks or with disk-grown pseudobulges. They also have no special correlation with dark matter halos beyond the fact that halo gravity controls galaxy formation. This leads to the suggestion that there are two modes of BH feeding, (1) local, secular and episodic feeding of small BHs in largely bulgeless galaxies that involves too little energy feedback to drive BH–host-galaxy coevolution and (2) global feeding in major galaxy mergers that rapidly grows giant BHs in short-duration events whose energy feedback does affect galaxy formation. After these quasar-like phases, maintenance-mode BH feedback into hot, X-ray-emitting gas continues to have a primarily negative effect in preventing late-time star formation when cold gas or gas-rich galaxies get accreted. Finally, the highest-mass galaxies inherit coevolution effects from smaller galaxies; the tightness of their BH correlations is caused mainly by averaging during dissipationless major mergers.
Hot Gas and AGN Feedback in Galaxies and Nearby Groups
Authors: Jones Christine , Forman William , Bogdan Akos , Randall Scott , Kraft Ralph , Churazov Eugene
Published: July 2013

Massive galaxies harbor a supermassive black hole at their centers. At high redshifts, these galaxies experienced a very active quasar phase, when, as their black holes grew by accretion, they produced enormous amounts of energy. At the present epoch, these black holes still undergo occasional outbursts, although the mode of their energy release is primarily mechanical rather than radiative. The energy from these outbursts can reheat the cooling gas in the galaxy cores and maintain the red and dead nature of the early-type galaxies. These outbursts also can have dramatic effects on the galaxy-scale hot coronae found in the more massive galaxies. We describe research in three areas related to the hot gas around galaxies and their supermassive black holes. First we present examples of galaxies with AGN outbursts that have been studied in detail. Second, we show that X-ray emitting low-luminosity AGN are present in 80% of the galaxies studied. Third, we discuss the first examples of extensive hot gas and dark matter halos in optically faint galaxies.
Quasar activity in the neighbor Universe
Authors: Falomo R. , Bettoni D. , Karhunen K. , Kotilainen J. , Uslenghi M.
Published: July 2013

We investigate the properties of the galaxies hosting quasars in ~400 low redshift (z < 0.5) SDSS QSO that are in the “Stripe 82” sky area. For this region deep (r ~ 22.4 mag) u, b, v, r and i images are available and allow us to study both the host galaxies and the Mpc scale environments. This sample outnumbers previous studies of low-z QSOs. We present preliminary results of the properties of quasars activity and in particular we focus on the relationships among host galaxy luminosity, black hole mass, radio emission and the surrounding galaxy environments. We select from the SDSS - QSO Catalogue all the QSOs in the range of redshift 0.1<z<0.5 and in the Stripe82 region. This gives a total of 416 QSO. In this sample we are dominated by radio quiet quasars (about 5% are radio loud). In Fig. 1 we report the distribution of QSO in the plane redshift-MR (H0 = 70). The mean redshift of the sample is  = 0.39 and the average absolute magnitude is:  = −22.68. We implemented an automated procedure using AIDA (Uslenghi & Falomo 2011) to decompose the QSO images into nucleus and host galaxy luminosity. After masking of all contaminating sources in the field a 2D fitting is performed using PSF + galaxy model. In Fig. 1 we show an example of a QSO image in the sample and the distribution of the host galaxy absolute magnitude of the resolved objects.
Galaxy spectra from the UV to the mid-IR
Authors: Brown Michael J. I. , Moustakas John , Smith J.-D. T. , da Cunha Elisabete , Imanishi Masatoshi , Armus Lee , Brandl Bernhard R.
Published: July 2013

Templates and models of galaxy spectra are often essential for determining the physical properties of galaxies. Many commonly used templates have large systematic errors, which significantly impact photometric redshifts and k-corrections. We present a new library of 110 galaxy template spectra spanning from the ultraviolet to the mid-infrared. The templates combine optical, Spitzer and Akari spectra with MAGPHYS models, all normalised and verified with matched aperture photometry. Our library contains more galaxies, spans a broader range of colours and has smaller systematic errors than previous libraries of galaxy spectra.
The stellar populations of massive galaxies in the local Universe
Authors: McDermid Richard M.
Published: July 2013

I present a brief review of the stellar population properties of massive galaxies, focusing on early-type galaxies in particular, with emphasis on recent results from the ATLAS3D Survey. I discuss the occurence of young stellar ages, cold gas, and ongoing star formation in early-type galaxies, the presence of which gives important clues to the evolutionary path of these galaxies. Consideration of empirical star formation histories gives a meaningful picture of galaxy stellar population properties, and allows accurate comparison of mass estimates from populations and dynamics. This has recently provided strong evidence of a non-universal IMF, as supported by other recent evidences. Spatially-resolved studies of stellar populations are also crucial to connect distinct components within galaxies to spatial structures seen in other wavelengths or parameters. Stellar populations in the faint outer envelopes of early-type galaxies are a formidable frontier for observers, but promise to put constraints on the ratio of accreted stellar mass versus that formed ‘in situ’ - a key feature of recent galaxy formation models. Galaxy environment appears to play a key role in controlling the stellar population properties of low mass galaxies. Simulations remind us, however, that current day galaxies are the product of a complex assembly and environment history, which gives rise to the trends we see. This has strong implications for our interpretation of environmental trends.
Stellar population gradients in brightest cluster galaxies
Authors: Loubser S. I. , Sánchez-Blázquez P.
Published: July 2013

We present the stellar population and velocity dispersion gradients for a sample of 24 brightest cluster galaxies (BCGs) in the nearby Universe for which we have obtained high quality long-slit spectra at the Gemini telescopes. With the aim of studying the possible connection between the formation of the BCGs and their host clusters, we explore the relations between the stellar population gradients and properties of the host clusters, as well as the possible connections between the stellar population gradients and other properties of the galaxies. We find mean stellar population gradients (negative Δ[Z/H]/log r gradient of − 0.285 ± 0.064; small positive Δlog(age)/log r gradient of +0.069 ± 0.049; and null Δ[E/Fe]/log r gradient of -0.008 ± 0.032), that are consistent with those of normal massive elliptical galaxies. However, we find a trend between metallicity gradients and velocity dispersion (with a negative slope of − 1.616 ± 0.539), that is not found for the most massive ellipticals. Furthermore, we find trends between the metallicity gradients and K-band luminosities (with a slope of 0.173 ± 0.081) as well as the distance from the BCG to the X-ray peak of the host cluster (with a slope of − 7.546 ± 2.752). The latter indicates a possible relation between the formation of the cluster and that of the central galaxy.