Panel Discussion: American Tax Credits and Foreign Taxes and Royalties

This panel discussion primarily focuses on U.S. tax policy with regards to international oil companies

What Regulates Galaxy Evolution? Open Questions in Our Understanding of Galaxy Formation and Evolution

In April 2013, a workshop entitled "What Regulates Galaxy Evolution" was held at the Lorentz Center. The aim of the workshop was to bring together the observational and theoretical community working on galaxy evolution, and to discuss in depth of the current problems in the subject, as well as to review the most recent observational constraints. A total of 42 astrophysicists attended the workshop. A significant fraction of the time was devoted to identifying the most interesting "open questions" in the field, and to discuss how progress can be made. This review discusses the four questions (one for each day of the workshop) that, in our opinion, were the focus of the most intense debate. We present each question in its context, and close with a discussion of what future directions should be pursued in order to make progress on these problems.Comment: 36 pages, 6 Figures, submitted to New Astronomy Review

非星形成高密度銀河の運命

Tohoku University秋山正幸課

過去100億年の大質量円盤銀河の内部での星の集積と星形成の終焉

Tohoku University秋山正幸課

Understanding the formation and properties of galaxies from stellar kinematics

Obwohl die Entstehung und die Eigenschaften von Galaxien schon seit fast 100 Jahren Gegenstand astrophysikalischer Forschung sind, gibt es grundlegende Aspekte, welche bis heute nicht vollständig verstanden sind. Vor dem Hintergrund der kosmologischen Strukturbildung entwickeln sich Galaxien unter dem Einfluss diverser interner und externer physikalischer Prozesse. Ein komplexes Zusammenspiel dieser Prozesse, welche auf variierenden Zeitskalen agieren, formt die Galaxien die wir heute beobachten. Es ist bekannt, dass dieses Zusammenspiel maßgeblich die orbitale Struktur von Sternen innerhalb von Galaxien beeinflusst und daher Spuren in der Phasenraumverteilung hinterlässt. Die vorliegende Dissertation beschäftigt sich mit der Frage, welche Information aus der stellaren Kinematik extrahiert werden kann, um die Entstehung und Entwicklung von Galaxien umfassender zu verstehen. Im Speziellen untersuchen wir die Geschwindigkeitsverteilung entlang der Blickachse anhand ihrer Momente. Hierfür nutzen wir die hochmoderne hydrodynamische kosmologische \textit{Magneticum} Simulation, in welcher sich auf natürliche und selbstkonsistente Weise eine realistische und statistisch aussagekräftige Galaxienpopulation bildet. Um die kinematische Struktur von Galaxien in größerem Detail zu untersuchen, werden zusätzlich hochaufgelöste idealisierte Simulationen individueller Galaxienverschmelzungen analysiert. Der erste Teil der Arbeit bezieht sich zunächst auf das Zentrum elliptischer Galaxien. Im Einklang mit Beobachtungen finden wir im Allgemeinen eine bimodale Verteilung aus schnell rotierenden und langsam rotierenden Galaxien, mit konsistenten Häufigkeiten. Die Simulation reproduziert zudem die wichtigsten beobachteten Geschwindigkeitsstrukturen, wie gegenläufig oder entkoppelt rotierende Kerne. Mit Hilfe der dreidimensionalen Information der Simulation zeigen wir, dass es möglich ist, anhand von beobachtbaren Parametern die interne Anisotropie der Sterne abzuleiten. Dies bestätigt die Validität eines theoretischen Modells, welches zur Interpretation von Beobachtungen hinsichtlich der internen Struktur von Galaxien verwendet wird. Diese Resultate zeigen, dass die Magneticum Simulation ein exzellentes Laboratorium bereitstellt, um die stellare Kinematik und deren Ursprung zu erforschen. In diesem Zusammenhang finden wir, dass die Population aus langsam rotierenden Galaxien sich graduell seit z=2 aufbaut, und ein signifikanter Anteil dieser nun langsam rotierenden Galaxien ihren Drehimpuls durch eine massive Galaxienverschmelzung verloren hat. Im zweiten Teil untersuchen wir in einer detaillierten Fallstudie Ursprung, Stabilität und Dynamik eines gegenläufig rotierenden Kerns einer elliptischen Galaxie, die durch einen einzelnen massiven Verschmelzungsprozess zweier Spiralgalaxien in einer idealisierten Simulation entstanden ist. Wir können zeigen, dass solche Kerne aus neu geformten Sternen aufgebaut sind, deren Apoapsis sich innerhalb des Kernradius befindet. Das Rotationssignal verschwindet etwa 3Gyr nach der Galaxienkollision, ausgelöst durch die gravitative Vermischung der rotierenden Sterne mit Sternen, die den Kern auf stark elliptischen Bahnen intrudieren. Während seiner Lebenszeit vollführt der Kern eine periodische globale Bewegung. Diese Bewegung ist ein Indiz für die Konservierung des orbitalen Drehimpulses in der gasförmigen Komponente, welche später durch Sternentstehung den Kern aufbaut. Im dritten Teil erweitern wir unsere Analyse auf den stellaren Halo der Galaxien. Aufgrund der niedrigen Dichten und damit verbundenen langen Relaxationszeiten dokumentiert der stellare Halo eine Vielfalt an Informationen über Verschmelzungen mit anderen Galaxien. Im Einklang mit Beobachtungen finden wir drei Arten von radialen Rotationsvariationen: stark im Zentrum und schwächer im Halo, kontinuierlich ansteigend mit hoher Amplitude und durchgehend flach mit niedriger Amplitude. Diese Variationen in der Rotation sind Resultat des komplexen Zusammenspiels von interner Sternenstehung und der Akkretion von Sternen. Für die erste Art von Galaxien finden wir starke Indizien, dass der Halo und das Zentrum sich entkoppelt entwickeln. Während das Zentrum einer alten Scheibe entspricht die schon bei z~2 existiert und durch interne Sternenstehung wächst, baut sich der Halo durch das anisotrope Akkretieren kleiner Strukturen auf. Dieses Szenario legt nahe, dass eine Verbindung zwischen dem kinematischen Übergang und dem Übergang von insitu geformten zu akkretierten Sternen besteht. Wir demonstrieren, dass eine solche Korrelation existiert, jedoch mit einer gewissen Streuung, die durch einen vermischten Übergangsbereich verursacht wird. Abschließend wird die Form der Geschwindigkeitsverteilung genauer untersucht, indem wir die Schiefe und Wölbung der Verteilung miteinbeziehen, um die maximale Information aus der Geschwindigkeitsverteilung zu extrahieren. Dies wird erstmals für eine kosmologische Simulation durchgeführt. Wir zeigen, dass Galaxien mit ansteigender stellarer Masse eine zunehmend schmalere Geschwindigkeitsverteilung aufweisen. Diese Veränderung weist auf einen generellen Übergang in der orbitalen Konfiguration hin. Zudem können wir zeigen, dass die globalen wie auch räumlich aufgelösten höheren Momente Rückschlüsse auf die Entstehung von Galaxien zulassen. Galaxien deren lokale Schiefe stark mit der lokalen Rotationsuntestützung korreliert/anti-korreliert, weisen eine erhöhte intrinsische Sternenstehung und ein erhöhtes Reservoir an kaltem Gas auf. Zusammenfassend zeigt diese Dissertation, dass die stellare Geschwindigkeitsverteilung von Galaxien wertvolle Informationen über die Entstehung und Entwicklung von Galaxien enthält. Unsere Ergebnisse stellen aussagekräftige Interpretationen aktueller Beobachtungen dar und liefern Vorhersagen, die zum Verständnis zukünftiger Beobachtungen maßgeblich beitragen werden.Although the formation and properties of galaxies have been the subject of astrophysical research for almost 100 years, some fundamental aspects are still not fully understood. Against the background of large scale cosmological structure formation, galaxies develop under the influence of various physical processes which interplay in a complex manner to form the galaxies observed today. This includes internal as well as external processes that act on varying temporal and spatial scales. It is known that aspects of this interplay significantly influence the orbital structure of stars within galaxies, and therefore encode in the stellar phase-space distribution. This thesis addresses the question of which information can be extracted from the kinematics of stars in order to further understand the details of the formation and evolution of galaxies. In particular, we study the stellar line-of-sight velocity distribution (LOSVD) based on its moments. For this we use the state-of-the-art hydrodynamic cosmological Magneticum Pathfinder simulation, which implements a variety of relevant physical mechanisms in order to build a realistic and statically meaningful galaxy population in a self-consistent manner. In addition, high-resolution idealised simulations of individual galaxy mergers are analysed to examine the kinematic structure of galaxies in greater detail. The first part of the thesis is constrained to the centre of Early-Type Galaxies. In agreement with observations from integral field spectroscopy surveys, we find a bimodal distribution of fast and slow rotating galaxies with consistent frequencies. Furthermore, the simulation reproduces the most important observed velocity structures, such as counter-rotating or decoupled rotating cores. Exploiting the three-dimensional information provided by the simulation, we demonstrate that it is possible to infer the internal stellar anisotropy from observable parameters. This confirms the validity of a theoretical model, which is generally used to interpret observations regarding the internal kinematic structure of galaxies. These results show that the Magneticum Pathfinder simulation provides an excellent laboratory to study the kinematics of galaxies and to explore their origin. In this context we find that the population of slowly rotating galaxies builds up gradually since z=2, and a significant fraction loses its angular momentum due to massive galaxy merger. Furthermore, we investigate in a detailed case study the origin, stability and dynamics of a counter-rotating kinematically distinct core (KDC) in an elliptical galaxy formed in an isolated galaxy merger simulation. We show, that the KDC consists of stars that have been newly formed during the merger on orbits with an apoapsis within the core radius. The rotation signal disappears approximately 3Gyr after the galaxy merger, triggered by the gravitational mixing of the rotating stars with stars which intrude the KDC on strongly elliptical orbits. During its lifetime, the core performs a periodic global movement comparable to the precession of a gyroscope in a gravitational potential. This global motion originates from the conservation of the progenitor orbital angular momentum in the gaseous component, which later builds up the KDC through star formation. In the third part we expand the analysis to the stellar halo of galaxies, which encodes a variety of information about interactions with other galaxies for a long period of time due to the low densities and the associated long relaxation timescales in the halo. In agreement with observations we find three characteristic types of radial rotation variations: i) strong in the centre and increasingly weaker in the halo ii) continuously rising with high amplitude iii) continuously flat mostly with low amplitude. These variations in the rotation reflect the complex interplay of internal star formation and external accretion of stars. For the first type of galaxies, we find strong evidence that the halo and the centre are evolving decoupled. While the centre corresponds to an old disk which already exists at z~2 and grows through internal star formation, the halo is built up through the anisotropic accretion of small structures which are disrupted in the halo. This scenario suggests a connection between the kinematic transition and the transition from in-situ formed to accreted ex-situ stars. We demonstrate that such a correlation exists, with a certain scatter caused by a transition region where both in-situ and ex-situ stars are strongly mixed. This result represents an important interpretation of recent observations and prediction for future observations which will push the limits of radial coverage of IFS observations. Finally, to extract the maximum information from the LOSVD, its shape is examined more closely by including higher-order moments measuring the deviations from a Gaussian, i.e. the skewness and kurtosis. This is the first time this analysis is applied to galaxies from a fully cosmological simulation. We show that galaxies with higher stellar masses exhibit a more peaked LOSVD, indicating a transition in the global orbital configuration. Furthermore, we are able to extract information about the formation history of galaxies from the global as well as spatially resolved higher-order moments. Galaxies with a strong anticorrelation/correlation between the local skewness and rotational support exhibit increased insitu star formation and a larger reservoir of cold gas to prolong star formation. In summary, this thesis shows that the LOSVD of galaxies encodes valuable information about the formation and evolution of galaxies. Our findings represent meaningful interpretations of recent IFS observations and provide predictions that can be probed by future surveys which will be able to reach larger radii and redshifts and to include information about stellar populations

Galaxy Morphology In Cluster Environments

It is a well known fact that cluster environments favour early-type galaxies over late- type. However, the physical origin of the correlation remains uncertain. We focus specifically on the external environmental mechanisms responsible for morphologi- cal transformation of late-type into early-type galaxies using ∼ 30,000 satellites in 625 clusters from SDSS DR7. All the external processes have one factor in common which is the orbital path taken by a satellite through the cluster that determines the extent of the environmental effects. We use results from orbital libraries extracted from N-body simulations. These give a probabilistic mapping between normalized projected phase-space (R, V ) coordinates to lookback time to cluster infall. The look back time is the key ingredient that traces how far the satellite is in its orbit compared to the cluster centre. Using these results, we explore the effects of a de- crease in disc luminosity caused by disc quenching and disc scale length reduction on satellite morphology quantified by the luminous bulge-to-total (B/T) ratio. Our findings suggest that satellites are quenched and their disc scale lengths are reduced after spending ∼ 5 Gyrs in the cluster which corresponds to ∼ 1 Gyr after pass- ing the pericenter. A drop in disc luminosity due to these processes has a small impact on morphology suggesting that other active processes such as harassment are responsible for further morphological transformations. Fitting to account for such processes over and above the ones responsible for a drop in disc luminosity, we find that satellites with B/T < 0.1 (pure disc systems) experience most drastic changes: their structure changes by developing a bulge component ∼ 5 Gyrs after infall. Similarly, objects with 0.1 < B/T < 0.3, are affected by harassment over a longer time scale ∼ 7 Gyrs suggesting that satellites with a bulge component are more resistant to harassment compared to pure disc systems. We conclude that the density-morphology relationship is a manifestation of both hydrodynamical as well as gravitational processes driving late-type to early-type morphology

Propuesta de elaboración de fermentos naturales a base de frutas del cantón Paute para aplicar a cortes de carne de cerdo

El cantón Paute es conocido por ser el paraíso de flores y frutas. La mayoría de su población se dedica a la producción de frutas es por esto que este proyecto de intervención analiza las principales características de cinco específicas frutas provenientes de la zona como son: la manzana, durazno, pera, reina claudia y saxuma, las cuales son la base de los productos a realizarse. En la primera parte del proyecto comprende todo lo que tiene que ver con las frutas antes mencionadas, desde su cultivo, producción, composición y características organolépticas. Se conocerá las diferentes formas de realizar una fermentación tanto acética como láctica para poder conservar las frutas por más tiempo y poder aplicarlas en diferentes cortes de carne de cerdo, en diferentes técnicas y elaboraciones culinarias para dar realce y apertura a las frutas desde otra perspectiva gastronómica. Al finalizar el proyecto se utilizará un grupo focal para exponer los productos y que estos sean degustados para obtener críticas y resultados de las recetas ya previamente trabajadas con el fin de obtener fichas técnicas y productos terminados, listos para ser aplicados en las diferentes preparaciones.Paute Canton is know for being a Paradise of flowers and fruits. The majority of its population Works on the product of fruits; this is why, this intervention Project analyzes the main characteristics of five regional fruits such as apples, peaches, pears, reina claudias, and saxumas. These are the base of the products to be made. The first part of the Project tackles the cultivation, production, composition and organoleptic characteristics of the fruits mentioned above. Besides, the diferent forms of preparing and acetic and lactic fermentation will be described to know to conserve fruits for long periods of time and be able to have them in different pork cuts, techniques, and culinary preparations raising importance and openness to fruits from a gastronomic perspective. At the end of the project, products will be exposed to a focus group and tasted by them to obtain critiques and results of the recioes previously worked to have data sheets and finished products ready to be applied in different preparations.Licenciado en Gastronomía y Servicios de Alimentos y BebidasCuenc

The Assembly of Massive Galaxy Clusters

Here we present an investigation into galaxy evolution in the cluster and intercluster filamentary environments, and follow the evolution of the large scale structure of the universe over 4 billion years. After designing and applying a new “filament finding algorithm” to galaxy survey data from the Sloan Digital Sky Survey and the Red Sequence Cluster Survey, we identify galaxies belonging to the intercluster filamentary environment, along with three other cluster populations. By carrying out a detailed photometric and spectroscopic investigation into the star formation rates of galaxies in different environments, we are able to shed light on the processes responsible for the cessation of star formation in cluster galaxies. In particular, we find that the quenching mechanisms of harassment and mergers are quite effective at pre‐processing galaxy groups outside of the cluster, contingent upon the local density being large enough. Next, we find that the filamentary environment at low redshift does have a considerable effect on the evolution of a galaxy. Specifically, we see evidence that the intrafilamentary medium has the potential to ram pressure strip the gaseous halos of infalling galaxies, and that infalling galaxies are subject to significant filament tidal forces at a few virial radii, enough to dismantle infalling groups within filaments. We see evidence for the filamentary environment inducing starbursts in infalling dwarf galaxies within groups, which we attribute to the exponentiation of the harassment mechanism by filament tidal forces. However, we conclude that this starburst population is relatively small, and thus starbursts are not a main contributor to the population of passive galaxies within clusters. Lastly, we compare the cluster composition between the two data sets, which provides insight into the assembly of galaxy clusters and the evolution of large scale structure over 4 billion years. From this comparison study, we see direct observational evidence for hierarchical clustering, and find that the dominant mechanism responsible for the population of “red and dead” galaxies in cluster cores is ram pressure stripping in the intracluster medium

The Lyman Alpha Reference Sample XI: Efficient Turbulence Driven Ly{\alpha} Escape and the Analysis of IR, CO and [C II]158 {\mu}m

We study the global dust and (molecular) gas content in the Lyman Alpha Reference Sample (LARS), i.e. 14 local star-forming galaxies. We characterize their interstellar medium and relate newly derived properties to quantities relevant for Ly$\alpha$ escape. We observed LARS galaxies with Herschel/PACS, SOFIA/FIFI-LS, the IRAM 30m telescope and APEX, targeting far-infrared (FIR) continuum and emission lines of [C II]158$\mu$m, [O I]63$\mu$m, [O III]88$\mu$m and low-J CO lines. Using Bayesian methods we derive dust model parameters and estimate total gas masses for all LARS galaxies, taking into account a metallicity-dependent gas-to-dust ratio. Star formation rates were estimated from FIR, [C II]158$\mu$m and [O I]63$\mu$m luminosities. LARS covers a wide dynamic range in the derived properties, with FIR-based star formation rates from $\sim$0.5-100 $M_{\odot}\ yr^{-1}$, gas fractions between $\sim$15-80% and gas depletion times ranging from a few hundred Myr up to more than 10 Gyr. The distribution of LARS galaxies in the $\Sigma_{gas}$ vs. $\Sigma_{SFR}$ (Kennicutt-Schmidt plane) is thus quite heterogeneous. However, we find that LARS galaxies with the longest gas depletion times, i.e. relatively high gas surface densities ($\Sigma_{gas}$) and low star formation rate densities ($\Sigma_{SFR}$), have by far the highest Ly$\alpha$ escape fraction. A strong $\sim$linear relation is found between Ly$\alpha$ escape fraction and the total gas (HI+H$_2$) depletion time. We argue that the Ly$\alpha$ escape in those galaxies is driven by turbulence in the star-forming gas that shifts the Ly$\alpha$ photons out of resonance close to the places where they originate. We further report on an extreme [C II]158$\mu$m excess in LARS 5, corresponding to $\sim$14$\pm$3% of the FIR luminosity, i.e. the most extreme [C II]-to-FIR ratio observed in a non-AGN galaxy to date