17610175
Are truncated stellar disks linked to the molecular gas density
We know that the slope of the radial, stellar light distribution in galaxies is well described by an exponential decline and this distribution is often truncated at a break radius ($R_{br}$). We don't have a clear understanding for the origin of these outer truncations and several hypotheses have been proposed to explain them. We want to test the various theories with direct observations of the cold molecular gas for a few truncated galaxies in comparison with the non-truncated ones. The answer to the existence of a possible link between truncated stellar disks and the molecular gas density cannot be obtained from CO maps in the literature, because so far there are no galaxies with a clear truncation observed in CO at high resolution.
11244261
Rotation curves and metallicity gradients from HII regions in spiral galaxies
In this paper we study long slit spectra in the region of H emission line of a sample of 111 spiral galaxies with recognizable and well defined spiral morphology and with a well determined environmental status, ranging from isolation to non-disruptive interaction with satellites or companions. The form and properties of the rotation curves are considered as a function of the isolation degree, morphological type and luminosity. The line ratios are used to estimate the metallicity of all the detected HII regions, thus producing a composite metallicity profile for dierent types of spirals. We have found that isolated galaxies tend to be of later types and lower luminosity than the interacting galaxies. The outer parts of the rotation curves of isolated galaxies tend to be flatter than in interacting galaxies, but they show similar relations between global parameters. The scatter of the Tully-Fisher relation defined by isolated galaxies is significantly lower than that of interacting galaxies. The (NII)/H ratios, used as a metallicity indicator, show a clear trend between Z and morphological type, t, with earlier spirals showing higher ratios; this trend is tighter when instead of t the gradient of the inner rotation curve, G, is used; no trend is found with the change in interaction status. The Z-gradient of the disks depends on the type, being almost flat for early spirals, and increasing for later types. The (NII)/H ratios measured for disk HII regions of interacting galaxies are higher than for normal/isolated objects, even if all the galaxy families present similar distributions of H Equivalent Width.
119422208
WINGS: a WIde-field Nearby Galaxy-cluster Survey. I. Optical imaging
This is the first paper of a series that will present data and scientific results from the WINGS project, a wide-field, multiwavelength imaging and spectroscopic survey of galaxies in 77 nearby clusters. The sample was extracted from the ROSAT catalogs of X-Ray emitting clusters, with constraints on the redshift (0.04 < z < 0.07) and distance from the galactic plane (|b |≥ 20 deg). The global goal of the WINGS project is the systematic study of the local cosmic variance of the cluster population and of the properties of cluster galaxies as a function of cluster properties and local environment. This data collection will allow the definition of a local, “zero-point” reference against which to gauge the cosmic evolution when compared to more distant clusters. The core of the project consists of wide-field optical imaging of the selected clusters in the B and V bands. We have also completed a multifiber, medium-resolution spectroscopic survey for 51 of the clusters in the master sample. The imaging and spectroscopy data were collected using, respectively, the WFC@INT and WYFFOS@WHT in the northern hemisphere, and the WFI@MPG and 2dF@AAT in the southern hemisphere. In addition, a NIR (J, K )s urvey of∼50 clusters and an Hα + U survey of some 10 clusters are presently ongoing with the WFCAM@UKIRT and WFC@INT, respectively, while a very-wide-field optical survey has also been programmed with OmegaCam@VST. In this paper we briefly outline the global objectives and the main characteristics of the WINGS project. Moreover, the observing strategy and the data reduction of the optical imaging survey (WINGS-OPT) are presented. We have achieved a photometric accuracy of ∼0.025 mag, reaching completeness toV ∼ 23.5. Field size and resolution (FWHM) span the absolute intervals (1.6–2.7) Mpc and (0.7–1.7) kpc, respectively, depending on the redshift and on the seeing. This allows the planned studies to obtain a valuable description of the local properties of clusters and galaxies in clusters.
1840
Cluster formation in the LMC
In this work we present preliminary results concerning the properties of about 50 clusters and associations located in a densely populated region at the Southern edge of the supershell LMC~4. The ages of the clusters and associations are derived. The cluster formation rate peaks at about 10-20 Myr ago corresponding to the age of the formation of LMC~4. Objects younger than 10 Myr are located close to CO clouds, indicating a possible trigger of the recent star formation by the interaction of the supershell with the interstellar medium. 
Isophotal analysis has been done for 50% of the clusters. A large number of objects present isophotal distortions commonly interpreted as sign of interaction. Cluster multiplets are coeval within 20 Myr, suggesting a common origin. This indicates that clusters possibly form in large groups. Our findings are in agreement with the unified view of multi-scale star formation, where a size-duration correlation is expected.
16975153
The bright galaxy population of five medium redshift clusters II. Quantitative galaxy morphology
Aims. Following the study presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 ≤ z ≤ 0.25 imaged in the central 0.5–2 Mpc in very good seeing conditions, we have studied the quantitative morphology of their bright galaxy population Methods. We analyzed the surface brightness profiles of the galaxy population in those clusters, after performing simulations in order to check the reliability of the fits. We also derived a quantitative morphological classification. Results. The structural parameters derived from these analyses are presented. We obtained that the structural parameters of E/S0 galaxies are similar to those shown by galaxies in low redshift clusters. However, the disc scales are different. In particular, the scales of the discs of galaxies in medium redshift clusters are statistically different than those located in similar galaxies in the Coma cluster. However, the scales of the discs of galaxies in medium redshift clusters are similar to nearby field galaxies. Conclusions. Our results suggest that the evolution of the disc component of galaxies in clusters is faster than in field ones. Mechanisms like galaxy harassment showing timescales of ∼1 Gyr could be responsible for this disc scale evolution. This indicates that spiral galaxies in clusters have undergone a strong evolution in the last 2.5 Gyr or that Coma is in some way anomalous.
119325667
The scaling relations of early{type galaxies in clusters ? I. Surface photometry in seven nearby clusters
This is the first paper of a series investigating the scaling relations of early–type galaxies in clusters. Here we illustrate the multi–band imagery and the image reduction and calibration procedures relative to the whole sample of 22 clusters at $0.05 \mathrel{\raise0.35ex\hbox{$\scriptstyle <$}\kern-0.6em \lower0.40ex\hbox{{$\scriptstyle \sim$}}}z \mathrel{\raise0.35ex\hbox{$\scriptstyle <$}\kern-0.6em \lower0.40ex\hbox{{$\scriptstyle \sim$}}}0.25$. We also present detailed surface photometry of 312 early–type galaxies in 7 clusters in the first redshift bin, $z \approx0.025$–0.075. We give for each galaxy the complete set of luminosity and geometrical profiles, and a number of global, photometric and morphological parameters. They have been evaluated taking into account the effects of seeing. Internal consistency checks and comparisons with data in the literature confirm the quality of our analysis. These data, together with the spectroscopic ones presented in the second paper of the series, will provide the local calibration of the scaling relations.
116975111
RICH for PANDA
Abstract The powerful particle identification detection system of the P ¯ ANDA (antiProton ANihilations at DArmstadt) experiment contains three Cherenkov detectors. In the forward direction a conventional RICH detector is planned. In the high solenoid field of the target spectrometer thin Cherenkov detectors using the DIRC principle are mandatory and are envisaged in the form of a barrel and a vertical disc. The combination of the time of arrival of the photons with their spatial image determines not only the particle velocity, but also the wavelength of the photons. Therefore dispersion corrections on the lower and upper detection threshold is possible. Investigations concerning the development of a 3D-Barrel-DIRC are discussed as well as two different studies realizing a new Disc-DIRC for the forward angles. One is based on the Time of Propagation (ToP) method the other on the readout with focusing light guides.
119456485
Measurement of the branching ratios psi-prime ---> e+ e-, psi-prime ---> J/psi pi pi and psi-prime ---> J/psi eta
The authors have measured several branching ratios for {psi}' decay using the data collected by FNAL E835 experiment during year 2000, obtaining {beta}({psi}' {yields} e{sup +}e{sup -}) = 0.0068 {+-} 0.0001 {+-} 0.0004, {beta}({psi}' {yields} J/{psi}{pi}{sup +}{pi}{sup -}) = 0.292 {+-} 0.005 {+-} 0.018, {beta}({psi}' {yields} J/{psi}{pi}{sup 0}{pi}{sup 0}) = 0.167 {+-} 0.005 {+-} 0.014 and {beta}({psi}' {yields} J/{psi}{eta}) = 0.028 {+-} 0.002 {+-} 0.002. They also present a measurement of the dipion mass distribution in the decays {psi}' {yields} J/{psi}{pi}{pi}.
108986863
Performance measurements of histe-V VLPC photon detectors for E835 at FNAL
A set of 144 VLPC chips has been used by experiment E835 at FNAL for the readout of its scintillating fiber detector. During the data taking, the fibers have been exposed to rates up to 2.5×104 mips/sec, corresponding to 3.5×106 photons/sec on each VLPC pixel surface. This paper reports about a study on rate dependence of gain and quantum efficiency throughout the run, as well as VLPC failure statistics during operation. No significant aging effects are observed. A review about the overall system performance is given.
123275132
The new scintillating fiber detector of E835 at Fermilab
Abstract The scintillating fiber tracker for the measurement of the polar coordinate θ for experiment E835 at Fermilab has been upgraded, by adding two extra layers (240 fibers each), at R ≈9 cm from the beam axis. Photons from the fibers are detected by Visible Light Photon Counters (VLPCs). The high granularity, flexibility and fast response of the scintillating fibers, combined with the high quantum efficiency of the VLPCs, allow high rate capability, high efficiency, good tracking and time resolution. Signals from the outer two layers are used to provide θ information to the first-level trigger.
54846524
Development of DIRC counters for the PANDA Experiment at FAIR
The PANDA experiment at the planned FAIR facility at GSI, Darmstadt, aims at measuring hadronic final states with unprecedented precision and luminosity. Superior particle identification of charged and neutral particles is mandatory to fulfil PANDA's physics aims. DIRC (Detection of Internally Reflected Cherenkov light) counters are foreseen for charged particle identification. A barrel DIRC will cover the central region while a disc DIRC will provide particle identification in the forward region. 
 
Three DIRC concepts differing in the radiator geometry and method for dispersion correction are studied. The barrel DIRC uses a novel imaging system and aims at exploiting a 3D reconstruction to mitigate dispersion effects. Two concepts are investigated for the forward disc DIRC. One concept employs passive dispersion correction and focussing light guides for image reconstruction. Alternatively, time-of-propagation measurements and a wave-length dependent photon detection system are investigated. The three detector designs share common developments such as investigating radiator properties and photon detection systems, and use the same test beam facilities.