Brescia, M.

Castellani, M.

Longo, G.

Mancini, E.

Pellecchia, L.

English

Archivio della ricerca - Università degli studi di Napoli Federico II

ADVANCES IN COMPUTATIONAL ASTROPHYSICS: METHODS, TOOLS, AND OUTCOMESASP Conference Series, Vol. 453R. Capuzzo-Dolcetta, M. Limongi & A. Tornambè, eds.c©2012 Astronomical Society of the PacificVOGCLUSTERS: An Example of DAMEWeb ApplicationM. Castellani,1 M. Brescia,2 E. Mancini,3 L. Pellecchia,3 and G. Longo31INAF - Astronomical Observatory of Rome,2INAF - Astronomical Observatory of Capodimonte (Naples)3Dept. of Physics, University Federico II (Naples)Abstract. We present the alpha release of the VOGCLUSTERS web application,specialized for data and text mining on globular clusters. It is one of the web2.0 tech-nology based services of Data Mining & Exploration (DAME) Program, devoted tomine and explore heterogeneous information related to globular clusters data.1. IntroductionAlong with the progress of the instruments for astronomical investigation of our Galaxy,the amount of data available for each globular cluster (GC) in the Milky Way is alsogrowing at a steady rate. In this very moment, several instruments from earth andfrom space are restlessly working to improve our detailed knowledge of such objects,which are of utterly importance for our understanding of the status and evolution ofour Galaxy. Moreover, since some of the older objects in the Universe are contained inglobular clusters, they have a key role also in many cosmological topics.The importance of GCs for a broad range of astronomical studies has been alreadyaddressed by Harris (1996). In that seminal paper (that introduced the famous onlineparameter compilation for galactic GCs) he also stressed the importance of having read-ily available up-to-date list of parameters for these unique objects. After all these years,his words appear even truer: not only we have new and more reliable parameters for agreat part of the known clusters, but - thanks also to modern surveys conducted in bandsdifferent from the visible, such as 2MASS (Skrutskie et al. 2006) - several other objectskeep going to increase our list of Milky Way clusters (e.g., Froebrich et al. 2008, MoniBidin et al. 2011).However, at the present day, such data appear still scattered among the various pa-pers and/or are reported in different (and for the most part not-homogeneous) web pagesand online catalogues. Such resources typically cannot be easily put in connection bypeople who want to make researches involving all kind of data.Nowadays it appears more and more important to delineate a strategy in order topresent the relevant information on a given cluster, or a range of clusters, in a singlesource and under a well-defined standard. This represents a necessary step to disclosea wide range of new investigations: the more we find ways to explore the parametersspace, the more we’ll be able to make useful science investigating upon the correlationsof those set of data.137138 Castellani et al.In the following it is presented a brief introduction to a project born to meet theserequirements, named VOGCLUSTERS ∗.2. A first step: the galactic globular clusters databaseThe Galactic Globular Clusters Database (gclusters) is an online resource †, focused onpresenting, in an organized way, a comprehensive list of bibliography, parameters anddata for each of the known GCs of the Milky Way (Castellani 2007).From the technical point of view, gcluster it is a ”classical” dynamical web site,and can be considered as a prototype of VOGCLUSTERS. Initially built around theHarris compilation, it is designed to allow a more flexible fruition of available data,allowing a number of operations, such as ordering clusters according to the value ofa given parameter, select objects whose parameters falling in a given interval, displayrelated bibliography and colour magnitude diagrams, or even drop a note pertinent tothat cluster, to be displayed online for the benefit of other users.Data are collected from several different sources, such as NASA AstrophysicsData System (ADS), Digital Sky Survey, related papers and websites, etc.3. A further step: moving to VOGCLUSTERS web applicationThe goal of the project VOGCLUSTERS is the development of a web application spe-cialized in data and text mining activities for astronomical archives related to galacticand extragalactic GCs. Main services are employed for the simple and quick navigationin the archives and their manipulation to correlate and integrate internal scientific in-formation. The archives are uniformed under Virtual Observatory (VO) standards andconstraints, in order to provide a homogenous and flexible environment, virtually capa-ble of interactions with an ever growing amount of external resources. At variance withgcluster, the project has not to be intended as a straightforward website, but as a realweb application.A website usually refers to the front-end interface through which the public inter-act with your information online. Websites are typically informational in nature with alimited amount of advanced functionality. Simple websites consist primarily of staticcontent where the data displayed is the same for every visitor and content changesare infrequent; more advanced websites may also have management and interactivecontent. A web application, or equivalently Rich Internet Application (RIA) usuallyincludes a website component but features additional advanced functionality to replaceor enhance existing processes. The interface design objective behind a web applicationis to simulate the intuitive, immediate interaction a user experiences with a desktopapplication.∗http://dame.dsf.unina.it/vogclusters.html†http://gclusters.altervista.orgThe VOGCLUSTERS Web Application 1394. The DAME frameworkDAME (DAta Mining & Exploration) is an international collaboration for data miningand machine learning research program, by exploiting the web2.0 technologies and ex-posing a series of applications and services for e-science communities. In particular,since the beginning, it is specialized in astrophysical services. Its products are hencebasically focused on data/text mining on massive data sets with machine learning meth-ods, on top of an hybrid distributed computing infrastructure (Brescia et al. 2010). TheDAME design architecture is implemented following the standard LAR (Layered Ap-plication Architecture) strategy, which leads to a software system based on a layeredlogical structure, where different layers communicate with each other via simple andwell-defined rules:1. Data Access Layer (DAL): the persistent data management layer, responsible ofthe data archiving system, including consistency and reliability maintenance.2. Business Logic Layer (BLL): the core of the system, responsible of the manage-ment of all services and applications implemented in the infrastructure, includinginformation flow control and supervision.3. User Interface (UI): responsible of the interaction mechanisms between the BLLand the users, including data and command I/O and views rendering.5. Details and status of the VOGCLUSTERS web appThe VOGCLUSTERS web application is hosting an integrated specialized toolset inthe DAME infrastructure, then taking fully advantage of its features. In particular, itsintegration deals with the technological solutions adopted, derived from DAME WebApplication Suite strategy and requirements. For example, concerning the user accesssecurity policy, VOGCLUSTERS shares the DAME user archive and, being on top ofpre-existing CLOUD-GRID hybrid architecture, it inherits integrity and security levels.Inside DAME, all VOGCLUSTERS authorized users are protected against privacy anddata consistency violations.The VOGCLUSTERS application is at an advanced phase of development. Itsmain features are:1. fully adoption of the DAME layered model;2. developed adopting the Google Web Toolkit (GWT). GWT make possible to usejava language (which is rapidly reaching the status of a standard for a great num-ber of scientific applications and projects, so that it is widely diffused among re-searchers), having java classes translated into an AJAX powered website. AJAXis an acronym for Asynchronous JavaScript and XML; it represents a group ofinterrelated web development methods used on the client-side to create interac-tive web applications. This choice allow us to develop powerful features whilemaintaining low the requirements of time and human resources.3. As usual for a DAME application, it is developed according to the standardsof VO. In this way, present and future archives in VOGCLUSTERS can take140 Castellani et al.Figure 1. The VOGCLUSTERS architecture: each box shows a different layer ofthe applicationadvantage of a well-defined environment expressly ideated for the easy exchangeof information between different resources.We consider that the knowledge of a GC is made of observational parameters,sometimes including also an history of the research evolution on their values. Theuser has the possibility to visualize and navigate the GCs archives (galactic and extra-galactic objects) and make correlations, in an constantly increasing number of ways,asking also for on-the-fly plots of different combinations and/or selections of data (com-ing soon). The information is transparently presented to the user in a simple and attrac-tive web interface (by merging worldwide distributed VO databases and registries). Sofar the user has the possibility to integrate/update these parameters adding new values,comments, images, diagrams, references, etc. Obtained results are not locked in theapplication: soon it will be possible to save them in a number of formats, like FITS,EPS, PDF, etc.The web application foresees three different categories of users, respectively, ad-ministrators, qualified (registered) and generic (not registered) users. The main dif-ferences between these user categories are related to the information manipulationrights. In particular the web application can be passively navigated by all users (genericcategory), can be integrated/updated by registered users (already authenticated withinDAME Suite) in terms of own data management and can be re-engineered by adminis-trators (typically DAME working group members). The first stable beta release of theapplication should be available by the end of October 2011.ReferencesBrescia, M. et al. 2010 in press (arXiv:1010.4843v2)Brescia, M. et al. 2010 in press (arXiv:1010.4843v2)Castellani, M. 2007, MemSait 79, 2Froebrich, D. et al. 2008, MNRAS, 390, 1598Harris, W.E. 1996, AJ, 112, 1487Moni-Bidin, C. et al. in press (arXiv:1109.1854)Skrutskie, M.F. et al. 1996, AJ, 131, 1163

VOGCLUSTERS: An Example of DAME Web Application

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VOGCLUSTERS: An Example of DAME Web Application

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