Study of the e+e− → π+π−ψ(2S) reaction at centre-of-mass energies above 4.600 GeV and search for the charged Zc(4430) exotic state at BESIII

Using six data samples with a total integrated luminosity of ∼5 fb−1 collected by the BESIII detector, the e+e− → π+π−ψ(2S) process is studied at centre-of-mass energies ranging from 4.6121 GeV to 4.6984 GeV. The measured cross-section of the e+e− → π+π−ψ(2S) reaction is consistent with published results and an enhancement can be seen around the 4.660 GeV, identified as the Y(4660) state. This represents an independent analysis of the previous BESIII results, fortifying the observation. The e+e− → π+π−ψ(2S) process is then studied via the π+π− invariant mass to search for the e+e− → f0(980)ψ(2S) interaction. The contribution of the e+e− → f0(980)ψ(2S) process is found for the first time and its cross-section is measured. In the e+e− → f0(980)ψ(2S) cross-section no particular structures can be recognised as the statistical uncertainty prevents any conclusion. The result poses a constraint on the Y (4660) state contribution to the e+e− → π+π−ψ(2S) cross-section since it is evident that the f0(980) contribution largely dominates the total production cross-section. More data is needed to see whether the Y(4660) resonance also appears in e+e− → f0(980)ψ(2S) data to further investigate its nature. Finally, a search for the Zc(4430)± exotic state is performed studying the π±ψ(2S) invariant mass, but no significant signal is found; a Bayesian upper limit at the 90% confidence level is set on the e+e− → π±Zc(4430)∓ process, leading to a production ratio R = σ(e+e− → π±Zc(4430)∓ → π+π−ψ(2S))/σ(e+e− → π+π−ψ(2S)) < 1.1%.Utilizzando sei campioni di dati con una luminosità integrata totale di ~5 fb−1 raccolti dal rivelatore BESIII, si è studiato il processo e+e− → π+π−ψ(2S) a energie del centro di massa comprese tra 4.6121 GeV e 4.6984 GeV. La sezione d’urto della reazione e+e− → π+π−ψ(2S) è in accordo con i risultati della letteratura confermando un aumento intorno a 4.660 GeV, identificato come lo stato Y(4660). Ciò rappresenta una misura indipendente dei precedenti risultati di BESIII, rafforzandone l’osservazione. Il processo e+e− → π+π−ψ(2S) è quindi analizzato tramite la massa invariante π+π− studiando l’interazione e+e− → f0(980)ψ(2S). Il contributo del processo e+e− → f0(980)ψ(2S) viene misurato per la prima volta. Nella sezione d’urto e+e− → f0(980)ψ(2S) non si riconoscono strutture particolari e l’incertezza statistica impedisce qualsiasi conclusione. I risultati pongono un vincolo sulla produzione dello stato Y(4660) all’interno del processo e+e− → π+π−ψ(2S), poiché è evidente che il contributo del mesone f0(980) domina largamente la sezione d’urto totale. Per investigare ulteriormente la natura della risonanza Y(4660) tramite il processo e+e− → f0(980)ψ(2S) è necessario raccogliere una quantità maggiore di dati. Infine, la ricerca dello stato esotico Zc(4430)± → π±ψ(2S) non ha prodotto alcun segnale significativo; viene posto, quindi, un limite bayesiano al livello di confidenza del 90% sul processo e+e− → π±Zc(4430)∓, che permette di stimare il rapporto di produzione R = σ(e+e− → π±Zc(4430)∓ → π+π−ψ(2S))/σ(e+e− → π+π−ψ(2S)) < 1.1%

The Universality of the Fundamental Plane of E and S0 Galaxies. Spectroscopic data

We present here central velocity dispersion measurements for 325 early-type galaxies in eight clusters and groups of galaxies, including new observations for 212 galaxies. The clusters and groups are the A262, A1367, Coma (A1656), A2634, Cancer and Pegasus clusters, and the NGC 383 and NGC 507 groups. The new measurements were derived from medium dispersion spectra, that cover 600 A centered on the Mg Ib triplet at lambda ~ 5175. Velocity dispersions were measured using the Tonry & Davis cross-correlation method, with a typical accuracy of 6%. A detailed comparison with other data sources is made.Comment: 12 pages, 5 tables, 3 figures, to appear in AJ. Note that tables 2 and 3 are in separate files, as they should be printed in landscape forma

Seeking the Local Convergence Depth. I. TF Observations of the Clusters A168, A397, A569, A1139, A1228, and A1983

We present first results of an all-sky observing program designed to improve the quality of the I band Tully-Fisher (TF) template and to obtain the reflex motion of the Local Group with respect to clusters to z = 0.06. We are obtaining between 5 and 15 TF measurements per cluster on a sample of 50 clusters at intermediate redshifts (0.02 < z < 0.06). Presentation of the data for seven Abell clusters of galaxies is given here. This data incorporates methods for estimating the true inclination of a spiral disk, an observational parameter undervalued for small angular-sized galaxies or for galaxies observed in poor seeing conditions.Comment: 21 pages, uses AAS LaTeX, 3 tables and 8 postscript figures (only first page of fig. 6 included in this version); to appear in the Astronomical Journa

F-VIPGI: a new adapted version of VIPGI for FORS2 spectroscopy. Application to a sample of 16 X-ray selected galaxy clusters at 0.6 < z < 1.2

The goal of this paper is twofold. Firstly, we present F-VIPGI, a new version of the VIMOS Interactive Pipeline and Graphical Interface (VIPGI) adapted to handle FORS2 spectroscopic data. Secondly, we investigate the spectro-photometric properties of a sample of galaxies residing in distant X-ray selected galaxy clusters, the optical spectra of which were reduced with this new pipeline. We provide basic technical information about the innovations of the new software and, as a demonstration of the capabilities of the new pipeline, we show results obtained for 16 distant (0.65 < z < 1.25) X-ray luminous galaxy clusters selected within the XMM-Newton Distant Cluster Project. We performed a spectral indices analysis of the extracted optical spectra of their members, based on which we created a library of composite high signal-to-noise ratio spectra representative of passive and star-forming galaxies residing in distant galaxy clusters. The spectroscopic templates are provided to the community in electronic form. By comparing the spectro-photometric properties of our templates with the local and distant galaxy population residing in different environments, we find that passive galaxies in clusters appear to be well evolved already at z = 0.8 and even more so than the field galaxies at similar redshift. Even though these findings would point toward a significant acceleration of galaxy evolution in densest environments, we cannot exclude the importance of the mass as the main evolutionary driving element either. The latter effect may indeed be justified by the similarity of our composite passive spectrum with the luminous red galaxies template at intermediate redshift.Comment: 15 pages, 15 figures, in press on Astronomy and Astrophysic

The Spatial Distribution, Kinematics, and Dynamics of the Galaxies in the Region of Abell 2634 and 2666

A total of 663 galaxies with known redshifts in a $6\deg\!\times 6\deg$ field centered on A2634, including 211 new measurements, are used to study the structure of this cluster and its surroundings. Two samples, ---one containing 200 galaxies within two degrees from the cluster center and a second, magnitude-limited, of 118 galaxies within the central half degree---, are used to examine the structure, kinematics, dynamics of A2634. We show that early-type galaxies appear to be a relaxed system, while the spiral population eschews the center of the cluster and exhibits both a multimodal velocity distribution and a much larger velocity dispersion than the ellipticals. We find no evidence of significant substructure in the central regions supportive of a recent merger of two subclusters, a scenario that has been suggested to explain the bending of the tails of the cluster central radio source (3C 465). We also conclude that the adoption of lenient membership criteria that ignore the dynamical complexity of A2634 are unlikely to be responsible for the conflictual results reported on the motion of this cluster with respect to the CMB. The kinematical and dynamical analysis is extended to A2634's close companion, A2666, and to two distant background clusters at 18,000 and 37,000 $\rm km s^{-1}$.Comment: 52 pages (AAS LaTeX macro v3.0). 5 Tables and 18 Figures available on request. To appear in the ApJ. JMS-94-0

Large-scale retrospective relative spectro-photometric self-calibration in space

We consider the application of relative self-calibration using overlap regions to spectroscopic galaxy surveys that use slit-less spectroscopy. This method is based on that developed for the SDSS by Padmanabhan at al. (2008) in that we consider jointly fitting and marginalising over calibrator brightness, rather than treating these as free parameters. However, we separate the calibration of the detector-to-detector from the full-focal-plane exposure-to-exposure calibration. To demonstrate how the calibration procedure will work, we simulate the procedure for a potential implementation of the spectroscopic component of the wide Euclid survey. We study the change of coverage and the determination of relative multiplicative errors in flux measurements for different dithering configurations. We use the new method to study the case where the flat-field across each exposure or detector is measured precisely and only exposure-to-exposure or detector-to-detector variation in the flux error remains. We consider several base dither patterns and find that they strongly influence the ability to calibrate, using this methodology. To enable self-calibration, it is important that the survey strategy connects different observations with at least a minimum amount of overlap, and we propose an "S"-pattern for dithering that fulfills this requirement. The final survey strategy adopted by Euclid will have to optimise for a number of different science goals and requirements. The large-scale calibration of the spectroscopic galaxy survey is clearly cosmologically crucial, but is not the only one.Comment: 23 pages, 19 figures, Accepted for publication in MNRAS, 201

Test on LUCIFER calibrator science frames

In order to find the best way to combine together telluric spectra and compute a sensitivity function, we observed different scientific frames of telluric stars. During this exploration we detected strange changes in spectra obtained from consecutive frame, this variability prevents us to compute a suitable sensitivity function, so we need to investigate better these frames

Problem with MODS data in the blue channel

During the 2013 June Italian run, a MODS blue proposal (MOS) has been observed (ID 31) and reduced. The PI is interested in measuring absorption features of high redshift objects. These feature are expected to be observed in the bluest region of the spectra

SIPGI: an interactive pipeline for spectroscopic data reduction

SIPGI is a spectroscopic pipeline for the data reduction of optical/near-infrared data acquired by slit-based spectrographs. SIPGI is a complete spectroscopic data reduction environment retaining the high level of flexibility and accuracy typical of the standard "by-hand" reduction methods but with a significantly higher level of efficiency. This is obtained exploiting three main concepts: 1) a built-in data organiser to classify the data, together with a graphical interface; 2) the instrument model (analytic description of the main calibration relations); 3) the design and flexibility of the reduction recipes: the number of tasks required to perform a complete reduction is minimised, preserving the possibility to verify the accuracy of the main stages of data-reduction process. The current version of SIPGI manages data from the MODS and LUCI spectrographs mounted at the Large Binocular Telescope (LBT) with the idea to extend SIPGI to support other through-slit spectrographs.Comment: 4 pages, 3 figure, to appear in proceedings of the Astronomical Data Analysis Software and Systems (ADASS) XXXII, virtual conference held 31 October - 4 November 202