Evolution of the characteristic curves in the restricted three-body problem in terms of the mass parameter

In this work, we study the evolution of the families of simple symmetric periodic orbits in the restricted three-body problem whatever the value of the mass parameter μ. To classify these characteristic curves, we introduce a topological characterization of both orbits and families. Starting from the work of Strömgren for the Copenhagen case, we analyze the evolution of these families, when the mass parameter μ varies in (0, 1/2], focusing on their topological characterization, the existence of asymptotic points and the appearance of certain types of orbits such as horseshoe orbits. Lastly, we consider two samples, the Earth–Moon and Sun–Jupiter systems and classify the different types of orbits for these systems

FeNi-based magnetoimpedance multilayers: Tailoring of the softness by magnetic spacers

The microstructure and magnetic properties of sputtered permalloy films and FeNi(170 nm)/X/FeNi(170 nm) (X=Co, Fe, Gd, Gd-Co) sandwiches were studied. Laminating of the thick FeNi film with various spacers was done in order to control the magnetic softness of FeNi-based multilayers. In contrast to the Co and Fe spacers, Gd and Gd-Co magnetic spacers improved the softness of the FeNi/X/FeNi sandwiches. The magnetoimpedance responses were measured for [FeNi/Ti(6 nm)] 2/FeNi and [FeNi/Gd(2 nm)] 2/FeNi multilayers in a frequency range of 1-500 MHz: for all frequencies under consideration the highest magnetoimpedance variation was observed for [FeNi/Gd(2 nm)] 2/FeNi multilayers. © 2012 American Institute of Physics

Outflows of hot molecular gas in ultra-luminous infra-red galaxies mapped with VLT-SINFONI

We present the detection and morphological characterization of hot molecular gas outflows in nearby ultra-luminous infrared galaxies, using the near-IR integral-field spectrograph SINFONI on the VLT. We detect outflows observed in the 2.12 micron H$_{2}$ 1-0 S(1) line for three out of four ULIRGs analyzed; IRAS 12112+0305, 14348-1447, and 22491-1808. The outflows are mapped on scales of 0.7-1.6 kpc, show typical outflow velocities of 300-500 km/s, and appear to originate from the nuclear region. The outflows comprise hot molecular gas masses of ~6-8x10$^3$ M(sun). Assuming a hot-to-cold molecular gas mass ratio of 6x10$^{-5}$, as found in nearby luminous IR galaxies, the total (hot+cold) molecular gas mass in these outflows is expected to be ~1x10$^{8}$ M(sun). This translates into molecular mass outflow rates of ~30-85 M(sun)/yr, which is a factor of a few lower than the star formation rate in these ULIRGs. In addition, most of the outflowing molecular gas does not reach the escape velocity of these merger systems, which implies that the bulk of the outflowing molecular gas is re-distributed within the system and thus remains available for future star formation. The fastest H$_{2}$ outflow is seen in the Compton-thick AGN of IRAS 14348-1447, reaching a maximum outflow velocity of ~900 km/s. Another ULIRG, IRAS 17208-0014, shows asymmetric H$_{2}$ line profiles different from the outflows seen in the other three ULIRGs. We discuss several alternative explanations for its line asymmetries, including a very gentle galactic wind, internal gas dynamics, low-velocity gas outside the disk, or two superposed gas disks. We do not detect the hot molecular counterpart to the outflow previously detected in CO(2-1) in IRAS 17208-0014, but we note that our SINFONI data are not sensitive enough to detect this outflow if it has a small hot-to-cold molecular gas mass ratio of < 9x10$^{-6}$.Comment: Accepted for publication in A&A (11 pages, 10 figures

Integral field optical spectroscopy of a representative sample of ULIRGs: I. The Data

We present a project aimed at studying the structure, dust distribution, ionization state, and kinematics of a representative sample of 22 ULIRGs. The galaxies in the sample undergo different merger phases (they are evenly divided between pre- and post-coalescence systems) and ionization stages (27% HII, 32% LINER, 18% Seyfert, and 23% mixed classifications) over a wide infrared luminosity range (11.8<Lir/Lsun<12.6), which also includes some galaxies of low luminosity. The main aims of this paper are to present the sample and discuss the structure of the stellar and ionized gas components. Our results imply that evolution caused by a merger is occurring in the ionized gas structure of ULIRGs. The present study relies on the use of integral field optical spectroscopy data obtained with the INTEGRAL instrument at the 4.2 m William Herschel Telescope.Comment: To appear in A&A. Paper with higher quality images can be found at http://hera.ph1.uni-koeln.de/ftpspace/maca/Catalog

Integral Field Spectroscopy based H\alpha\ sizes of local Luminous and Ultraluminous Infrared Galaxies. A Direct Comparison with high-z Massive Star Forming Galaxies

Aims. We study the analogy between local U/LIRGs and high-z massive SFGs by comparing basic H{\alpha} structural characteristics, such as size, and luminosity (and SFR) surface density, in an homogeneous way (i.e. same tracer and size definition, similar physical scales). Methods. We use Integral Field Spectroscopy based H{\alpha} emission maps for a representative sample of 54 local U/LIRGs (66 galaxies). From this initial sample we select 26 objects with H{\alpha} luminosities (L(H{\alpha})) similar to those of massive (i.e. M\ast \sim 10^10 M\odot or larger) SFGs at z \sim 2, and observed on similar physical scales. Results. The sizes of the H{\alpha} emitting region in the sample of local U/LIRGs span a large range, with r1/2(H{\alpha}) from 0.2 to 7 kpc. However, about 2/3 of local U/LIRGs with Lir > 10^11.4 L\odot have compact H{\alpha} emission (i.e. r1/2 < 2 kpc). The comparison sample of local U/LIRGs also shows a higher fraction (59%) of objects with compact H{\alpha} emission than the high-z sample (25%). This gives further support to the idea that for this luminosity range the size of the star forming region is a distinctive factor between local and distant galaxies of similar SF rates. However, when using H{\alpha} as a tracer for both local and high-z samples, the differences are smaller than the ones recently reported using a variety of other tracers. Despite of the higher fraction of galaxies with compact H{\alpha} emission, a sizable group (\sim 1/3) of local U/LIRGs are large (i.e. r1/2 > 2 kpc). These are systems showing pre-coalescence merger activity and they are indistinguishable from the massive high-z SFGs galaxies in terms of their H{\alpha} sizes, and luminosity and SFR surface densities.Comment: Accepted for publication in A&A. (!5 pages, 7 figures, 2 tables

Identifying and understanding road-constrained areas of interest (AOIs) through spatiotemporal taxi GPS data: A case study in New York City

Urban areas of interest (AOIs) represent areas within the urban environment featuring high levels of public interaction, with their understanding holding utility for a wide range of urban planning applications. Within this context, our study proposes a novel space-time analytical framework and implements it to the taxi GPS data for the extent of Manhattan, NYC to identify and describe 31 road-constrained AOIs in terms of their spatiotemporal distribution and contextual characteristics. Our analysis captures many important locations, including but not limited to primary transit hubs, famous cultural venues, open spaces, and some other tourist attractions, prominent landmarks, and commercial centres. Moreover, we respectively analyse these AOIs in terms of their dynamics and contexts by performing further clustering analysis, formulating five temporal clusters delineating the dynamic evolution of the AOIs and four contextual clusters representing their salient contextual characteristics

Profiling the Dynamic Pattern of Bike-sharing Stations: a case study of Citi Bike in New York City

This research applies a hierarchical k-means clustering method on the TF-IDF weighted 2019 cycling transactions from the Citi Bike bike-sharing system operating in New York City, with the primary goal of investigating the spatiotemporal usage pattern of its docking points. With a particular focus on bike-sharing stations in Manhattan, we classify 504 stations into four main clusters featuring heterogeneous dynamic usages, including leisure-oriented, residentialoriented, workplace-oriented, and off-peak oriented. We interpret each cluster based on their salient characteristics and anticipate possible future directions of this work

Metropolitan Mobility In Spain Are We Tending Towards Sustainability?

There is a growing concern in the urban transport field about the development of a data set of indicators that would allow to undertake ongoing monitoring and evaluation of current transportation policies, compare data from territories facing the same kind of challenges, identify good practices and strategies to be followed, and strengthen the information, participation and decision-making process. These data set of indicators, known as observatories, are aimed to fulfil stakeholders needs, so that they achieve the precise knowledge to adopt pertinent policies. The Spanish Metropolitan Mobility Observatory, sponsored by the Spanish Ministry of Environment, was launched in 2003 by the Metropolitan Transport Authorities of the major metropolitan areas in Spain, and TRANSyT. Its scope is to identify those elements within urban transport policy packages which have had a more significant impact on mobility (i.e. global transport demand, travel time, modal split,…), and on land use patterns. And its main goal is to serve as basis for Metropolitan Transport Authorities to improve operation of their public transport system, and thus increasing their contribution to sustainable mobility. For itsFor its second edition, based on the year 2003, a set of data from the different Metropolitan Transport Authorities has been collected, in order to: Highlight public transport contribution to improve urban areas and sustainable development - Describe the role of Metropolitan Transport Authorities in achieving an attractive and quality public transport - Monitoring transport supply and demand characteristics, focusing on public transport - Analyse resources dedicated to the public transport system - Describe the financial models used for the public transport system - Highlight the main initiatives and innovations developed by Metropolitan areas This information will be compared to that one from the previous edition, and a statistical analysis will be conducted in order to identify those variables, which are likely to explainresults in most cities.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne

Recurrence of the blue wing enhancements in the high ionization lines of SDSS 1004+4112 A

We present integral field spectroscopic observations of the quadruple-lensed QSO SDSS 1004+4112 taken with the fiber system INTEGRAL at the William Herschel Telescope on 2004 January 19. In May 2003 a blueward enhancement in the high ionization lines of SDSS 1004+4112A was detected and then faded. Our observations are the first to note a second event of similar characteristics less than one year after. Although initially attributed to microlensing, the resemblance among the spectra of both events and the absence of microlensing-induced changes in the continuum of component A are puzzling. The lack of a convincing explanation under the microlensing or intrinsic variability hypotheses makes the observed enhancements particularly relevant, calling for close monitoring of this object.Comment: 4 pages, 5 figure

Metropolitan Mobility In Spain Are We Tending Towards Sustainability?

Workshop FThere is a growing concern in the urban transport field about the development of a data set of indicators that would allow to undertake ongoing monitoring and evaluation of current transportation policies, compare data from territories facing the same kind of challenges, identify good practices and strategies to be followed, and strengthen the information, participation and decision-making process. These data set of indicators, known as observatories, are aimed to fulfil stakeholders needs, so that they achieve the precise knowledge to adopt pertinent policies. The Spanish Metropolitan Mobility Observatory, sponsored by the Spanish Ministry of Environment, was launched in 2003 by the Metropolitan Transport Authorities of the major metropolitan areas in Spain, and TRANSyT. Its scope is to identify those elements within urban transport policy packages which have had a more significant impact on mobility (i.e. global transport demand, travel time, modal split,…), and on land use patterns. And its main goal is to serve as basis for Metropolitan Transport Authorities to improve operation of their public transport system, and thus increasing their contribution to sustainable mobility. For itsFor its second edition, based on the year 2003, a set of data from the different Metropolitan Transport Authorities has been collected, in order to: Highlight public transport contribution to improve urban areas and sustainable development - Describe the role of Metropolitan Transport Authorities in achieving an attractive and quality public transport - Monitoring transport supply and demand characteristics, focusing on public transport - Analyse resources dedicated to the public transport system - Describe the financial models used for the public transport system - Highlight the main initiatives and innovations developed by Metropolitan areas This information will be compared to that one from the previous edition, and a statistical analysis will be conducted in order to identify those variables, which are likely to explainresults in most cities.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne