Star formation in early-type galaxies: the role of stellar winds and kinematics

Early-type galaxies (ETGs) host a hot ISM produced mainly by stellar winds, and heated by Type Ia supernovae and the thermalization of stellar motions. High resolution 2D hydrodynamical simulations showed that ordered rotation in the stellar component results in the formation of a centrifugally supported cold equatorial disc. In a recent numerical investigation we found that subsequent generations of stars are formed in this cold disc; this process consumes most of the cold gas, leaving at the present epoch cold masses comparable to those observed. Most of the new stellar mass formed a few Gyrs ago, and resides in a disc.Comment: 2 pages, 1 figure, to appear in proceedings of IAU Symposium 315, "From Interstellar Clouds to Star-Forming Galaxies: Universal Processes?", P. Jablonka, F. Van der Tak & P. Andre', ed

AOIPS 3 User's guide. Volume 1: Overview and software utilization

This is Volume I of the Atmospheric and Oceanographic Information Processing System (AOIPS) User's Guide. AOIPS 3 is the version of the AOIPS software as of April 1989. The AOIPS software was developed jointly by the Goddard Space Flight Center and General Sciences Corporation. Volume 1 is intended to provide the user with an overall guide to the AOIPS system. It introduces the user to AOIPS system concepts, explains how programs are related and the necessary order of program execution, and provides brief descriptions derived from on-line help for every AOIPS program. It is intended to serve as a reference for information such as: program function, inmput/output variable descriptions, program limitations, etc. AOIPS is an interactive meteorological processing system with capabilities to ingest and analyze the many types of meteorological data. AOIPS includes several applications in areas of relevance to meteorological research. AOIPS is partitioned into four applications components: satellite data analysis, radar data analysis, aircraft data analysis, and utilities

The Effect of the AGN Feedback on the Interstellar Medium of Early-Type Galaxies: 2D Hydrodynamical Simulations of the Low-Rotation Case

We present 2D hydrodynamical simulations for the evolution of early-type galaxies containing central massive black holes (MBHs), starting at age 2 Gyr. The code contains accurate and physically consistent radiative and mechanical AGN wind feedback, with parsec-scale central resolution. Mass input comes from stellar evolution; energy input includes Type Ia and II supernova and stellar heating; star-formation is included. Realistic, axisymmetric dynamical models for the galaxies are built solving the Jeans' equations. The lowest mass models (Mstar = 8 10^{10}Msun) develop global outflows sustained by SNIa's heating, ending with a significantly lower amount of hot gas and new stars. In more massive models, nuclear outbursts last to the present epoch, with large and frequent fluctuations in nuclear emission and from the gas (Lx). Each burst last ~ 10^{7.5} yr, during which (for r < 2-3 kpc) cold, inflowing, and hot, outflowing gas phases coexist. The Lx-T relation for the gas matches that of local galaxies. AGN activity causes positive feedback for star formation. Roughly half of the total mass loss is recycled into new stars (DeltaMstar), just ~ 3% of it is accreted on the MBH, the remainder being ejected from the galaxy. The ratio between the mass of gas expelled to that in to new stars, the load factor, is ~0.6. Rounder galaxies shapes lead to larger final MBH masses, DeltaMstar, and Lx. Almost all the time is spent at very low nuclear luminosities, yet one quarter of the total energy is emitted at an Eddington ratio > 0.1. The duty-cycle of AGN activity approximates 4% (Abridged).Comment: 26 pages, 15 figure, submitted to ApJ. Comments welcom

AOIPS 3 user's guide. Volume 2: Program descriptions

The Atmospheric and Oceanographic Information Processing System (AOIPS) 3 is the version of the AOIPS software as of April 1989. The AOIPS software was developed jointly by the Goddard Space Flight Center and General Sciences Corporation. A detailed description of very AOIPS program is presented. It is intended to serve as a reference for such items as program functionality, program operational instructions, and input/output variable descriptions. Program descriptions are derived from the on-line help information. Each program description is divided into two sections. The functional description section describes the purpose of the program and contains any pertinent operational information. The program description sections lists the program variables as they appear on-line, and describes them in detail

Cut-free Calculi and Relational Semantics for Temporal STIT Logics

We present cut-free labelled sequent calculi for a central formalism in logics of agency: STIT logics with temporal operators. These include sequent systems for Ldm , Tstit and Xstit. All calculi presented possess essential structural properties such as contraction- and cut-admissibility. The labelled calculi G3Ldm and G3Tstit are shown sound and complete relative to irreflexive temporal frames. Additionally, we extend current results by showing that also Xstit can be characterized through relational frames, omitting the use of BT+AC frames

Geophysical and stratigraphical research into deep groundwater and intruding seawater in the mediterranean area (the Salento Peninsula, Italy)

International audienceGeological, geophysical and hydrological surveys were performed in an area between Lecce to the North and Otranto to the South on the Lower Adriatic coast of Italy in order to verify the ``state of health'' of the ground water in the deep aquifer, which is characterised by Mesozoic carbonatic formations and is permeable due to fracturing and karstic phenomena. This area was chosen because it is highly urbanised, and contains many wells, some of which were intensively studied from a geological and hydro-geological point of view in 1987. The first phase of the research consisted of a stratigraphical and geological study, based on geological surveys of the surface and the subsoil by direct observation of borehole cores and the collection and analysis of existing stratigraphical data on wells in the area. The stratigraphical and hydrogeological data are kept in the archives of local agencies. The collected data were organised in a single database managed by an appropriate software (ARCVIEW). Numerous geological cross sections of the territory were studied in order to characterise the subsoil. Subsequently, multi-parameter surveys (O2, pH, temperature, TDS, conductivity) were carried out on the water-column of certain wells selected from those studied in 1987. This was to verify possible changes in the state of the groundwater since 1987. The surveys were carried out in two different periods (May and September) in order to identify potential differences between rainy and dry periods. Moreover, electrical tomography was used to characterise the various subsurface geological formations and possible saline water intrusion where direct information collected from the wells was lacking. From the research conducted it was possible to effect a stratigraphical characterisation of the subsoil and to verify overexploitation of the water resources resulting from the increasing number of wells, and the consequent deterioration of the aquifer due to saline water intrusion. The research also confirms the validity of geophysical methods for the study of hydro-geological issues

Ground penetrating radar surveys in a karst area for identification of geomorphological hazards.

Many coastal areas along the apulian coastlines (SE Italy) are intensely affected by sinkhole problems, which periodically cause damage to the main infrastructures, including the coastal roads and sparse settlements. Torre Castiglione is a locality situated at the boundary between the provinces of Lecce and Taranto, on the Jonian sea. Several sinkholes have in time affected the province road 340, which is a very important communication route during the summer, due to the tourist vocation of the area. Proximity of the site to the sea results in the mixing between sea water and fresh water, which determines a higher aggressivity toward the carbonate rock mass, and development of karst features and landforms, including caves. Due to the above reasons, the whole coastal sector is classified as with high geomorphological hazard. Aimed at investigating such hazard, a variety of direct and indirect surveys have been performed in the last years. Geological surveys, carried out through detailed field surveys, highlighted the presence of multi-storey cave systems, which upward stoping might eventually produce the formation of sinkholes. As concerns geomorphology, the population of identified sinkholes (more than 50) has been morphometrically characterized by measuring their depth, length, and width. The present contribution focuses on the geophysical surveys performed in the area. In detail, Ground Penetrating Radar (GPR) surveys have been carried out, due to the good resolution and the high penetration of the electromagnetic signal in geological settings characterized by presence of carbonate rocks. However, the presence of a karst aquifer in the area causes problems in the absorbing capacity of the signal. The main goal of this study is the analysis of the subsoil, aimed at testing the capability of GPR in a karst setting. A GSSI instrument was used, with antennae of 400 MHz, 200MHz and 100 MHz. The surveys were addressed to evaluate the capability of the method in such a setting, and to verify the velocity of propagation of the electromagnetic waves. Some scanlines were addressed to investigate, in particular, a sinkhole crossing the province road 340, by carrying out GPR profiles with a 200 MHz antenna at 90ns and 120 ns. The signal appeared to penetrate the subsoil at velocity of about 8 cm/ns. Elaboration of the data pointed out a series of cavities along the rural road running parallel to province road 340. In addition, the GPR survey highlighted the presence of complex karst systems at different depths, with cave size on the order of some tens of meters. A likely alignment in the cave direction seems to be shown, too

An analysis method of the vortex-induced vibrations of a tethered sphere

Vortex-induced vibrations (VIV) in systems with more than one degree of freedom often present complex synchronization among the motion components, also hidden by the randomness that characterizes the motion itself. A phase average method has been here developed and applied to the displacements of a tethered sphere, at low mass and damping, to analyze its xy trajectories over a wide range of reduced velocities, 5 ≤ U* ≤ 25 (Reynolds numbers, 5.1 × 103 ≤ Re ≤ 2.67 × 104). This method has allowed the identification of both the periodic and chaotic contribution of each motion component, accurately reconstructing the underlying trajectory periodic pattern. The two classical vibration modes, I and II, have been also observed. The method developed here was able to better rebuild the experimental data compared to other methods found in the relevant literature, providing useful insights into the study of the dynamic response of a freely-oscillating tethered sphere immersed in a steady flow

A framework for evaluating 3D topological relations based on a vector data model

3D topological relations are commonly used for testing or imposing the existence of desired properties between objects of a dataset, such as a city model. Currently available GIS systems usually provide a limited 3D support which usually includes a set of 3D spatial data types together with few operations and predicates, while limited or no support is generally provided for 3D topological relations. Therefore, an important problem to face is how such relations can be actually implemented by using the constructs already provided by the available systems. In this paper, we introduce a generic 3D vector model which includes an abstract and formal description of the 3D spatial data types and of the related basic operations and predicates that are commonly provided by GIS systems. Based on this model, we formally demonstrate how these limited sets of operations and predicates can be combined with 2D topological relations for implementing 3D topological relations

Programming and Audits Committee Meeting Agenda 10/26/2011

Student Government Senate Committee on Programming and Audits meeting agenda for 10/26/201