Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
9 result(s) for "Gallozzi, Stefano"
Sort by:
Concerns about ground based astronomical observations: a step to safeguard the astronomical sky
This article aims to highlight the impact for ground based astronomical observations in different windows of the electromagnetic spectrum coming from the deployment of fleets of telecommunications satellites. A particular attention is given to the problem of crowding of circumterrestrial space by medium/small size orbiting objects. Depending on their altitude and surface reflectivity, their contribution to the sky brightness is not negligible for professional ground based observations. With the huge amount of about 50,000 new artificial satellites for telecommunications planned to be launched in Medium and Low Earth Orbit, the mean density of artificial objects will be of >1 satellite for square sky degree; this will inevitably harm professional astronomical images leaving trails on them. Only one of these project, Starlink@SpaceX's, authorized by US Federal Communication Commission, plans to deploy about 42,000 not geostationary satellites, which will shine in sky after sunset and before sun dawn. Satellites will be observed in deep field images and particularly negative for scientific large area images used to search for Near Earth Objects, predicting and, eventually, avoiding possible impact events. Serious concerns are also common to other wavelengths eligible for ground based investigation, in particular for radio-astronomy, whose detectors are already saturated by the ubiquitous irradiation of satellites communication from Space stations as well as from the ground. The risk of running into the \"Kessler syndrome\" is also noteworthy. Understanding the risk for astronomical community, a set of actions are proposed in this paper to mitigate and contain the most dangerous effects arising from such changes in the population of small satellites. A dedicate strategy for urgent intervention to safeguard and protect each astronomical band observable from the ground is outlined.
Holographic Grid Cloud, a futurable high storage technology for the next generation astronomical facilities
In the immediate future holographic technology will be available to store a very large amount of data in HVD (Holographic Versatile Disk) devices. This technology make extensive use of the WORM (Write-Once-Read-Many) paradigm: this means that such devices allow for a simultaneous and parallel reading of millions of volumetric pixels (i.e. voxels). This characteristic will make accessible wherever the acquired data from a telescope (or satellite) in a quite-simultaneous way. With the support of this new technology the aim of this paper is to identify the guidelines for the implementation of a distributed RAID system, a sort of \"storage block\" to distribute astronomical data over different geographical sites acting as a single remote device as an effect of a property of distributed computing, the abstraction of resources. The end user will only have to take care on connecting in a opportune and secure mode (using personal certificates) to the remote device and will have access to all (or part) of this potential technology. A Storage-Block+Services engineered on such a platform will allow rapid scalability of resources, creating a \"network-distributed cloud\" of services for an instrument or a mission. It is recommended the use of a dedicated grid-infrastructure within each single cloud to enhance some critical tasks and to speed-up services working on the redundant, encrypted and compressed scientific data. The power, the accessibility, the degree of parallelism and of redundancy will only depend on the number of distributed storage-blocks: the higher this amount, the greater will be throughput of the IT-system. A storage-block of this kind is a meeting point between two technologies and two antithetical computing paradigms: the Grid-Computing and Cloud-Computing.
Concerns about ground based astronomical observations: quantifying satellites' constellations damages
This article is a second analysis step from the descriptive arXiv:2001.10952 preprint. This work is aimed to arise awareness to the scientific astronomical community about the negative impact of satellites' mega-constellations and put in place an approximated estimations about loss of scientific contents expected for ground based astronomical observations when about 50,000 satellites will be displaced in LEO orbit. The first analysis regards the impact on professional astronomical images in optical windows. Then the study is expanded to other wavelengths and astronomical ground based facilities (radio and higher energies) to better understand which kind of effects are expected. Authors also try to perform a quantitative economic estimation related to the loss of value for public finances committed to the ground based astronomical facilities armed by satellites' constellations. These evaluations are intended for general purposes, can be improved and better estimated, but in this first phase they could be useful as evidentiary material to quantify the damage in subsequent legal actions against further satellites deployments.
INDIGO-DataCloud:A data and computing platform to facilitate seamless access to e-infrastructures
This paper describes the achievements of the H2020 project INDIGO-DataCloud. The project has provided e-infrastructures with tools, applications and cloud framework enhancements to manage the demanding requirements of scientific communities, either locally or through enhanced interfaces. The middleware developed allows to federate hybrid resources, to easily write, port and run scientific applications to the cloud. In particular, we have extended existing PaaS (Platform as a Service) solutions, allowing public and private e-infrastructures, including those provided by EGI, EUDAT, and Helix Nebula, to integrate their existing services and make them available through AAI services compliant with GEANT interfederation policies, thus guaranteeing transparency and trust in the provisioning of such services. Our middleware facilitates the execution of applications using containers on Cloud and Grid based infrastructures, as well as on HPC clusters. Our developments are freely downloadable as open source components, and are already being integrated into many scientific applications.
Dwarf spheroidal satellites of M31: I. Variable stars and stellar populations in Andromeda XIX
We present B,V time-series photometry of Andromeda XIX (And XIX), the most extended (half-light radius of 6.2') of Andromeda's dwarf spheroidal companions, that we observed with the Large Binocular Cameras at the Large Binocular Telescope. We surveyed a 23'x 23' area centered on And XIX and present the deepest color magnitude diagram (CMD) ever obtained for this galaxy, reaching, at V~26.3 mag, about one magnitude below the horizontal branch (HB). The CMD shows a prominent and slightly widened red giant branch, along with a predominantly red HB, which, however, extends to the blue to significantly populate the classical instability strip. We have identified 39 pulsating variable stars, of which 31 are of RR Lyrae type and 8 are Anomalous Cepheids (ACs). Twelve of the RR Lyrae variables and 3 of the ACs are located within And XIX's half light radius. The average period of the fundamental mode RR Lyrae stars ( = 0.62 d, \\sigma= 0.03 d) and the period-amplitude diagram qualify And XIX as an Oosterhoff-Intermediate system. From the average luminosity of the RR Lyrae stars ( = 25.34 mag, \\sigma= 0.10 mag) we determine a distance modulus of (m-M)\\(_0\\)=\\(24.52\\pm0.23\\) mag in a scale where the distance to the Large Magellanic Cloud (LMC) is \\(18.5\\pm0.1\\) mag. The ACs follow a well defined Period-Wesenheit (PW) relation that appears to be in very good agreement with the PW relationship defined by the ACs in the LMC.
Hide and seek between Andromeda's halo, disk, and giant stream
Photometry in B, V (down to V ~ 26 mag) is presented for two 23' x 23' fields of the Andromeda galaxy (M31) that were observed with the blue channel camera of the Large Binocular Telescope during the Science Demonstration Time. Each field covers an area of about 5.1kpc x 5.1kpc at the distance of M31 ((m-M)o ~ 24.4 mag), sampling, respectively, a northeast region close to the M31 giant stream (field S2), and an eastern portion of the halo in the direction of the galaxy minor axis (field H1). The stream field spans a region that includes Andromeda's disk and the giant stream, and this is reflected in the complexity of the color magnitude diagram of the field. One corner of the halo field also includes a portion of the giant stream. Even though these demonstration time data were obtained under non-optimal observing conditions the B photometry, acquired in time-series mode, allowed us to identify 274 variable stars (among which 96 are bona fide and 31 are candidate RR Lyrae stars, 71 are Cepheids, and 16 are binary systems) by applying the image subtraction technique to selected portions of the observed fields. Differential flux light curves were obtained for the vast majority of these variables. Our sample includes mainly pulsating stars which populate the instability strip from the Classical Cepheids down to the RR Lyrae stars, thus tracing the different stellar generations in these regions of M31 down to the horizontal branch of the oldest (t ~ 10 Gyr) component.
ASTRI SST-2M Data Handling and Archiving System
The ASTRI project is the INAF (Italian National Institute for Astrophysics) flagship project developed in the context of the Cherenkov Telescope Array (CTA) international project. ASTRI is dedicated to the realization of the prototype of a Cherenkov small-size dual-mirror telescope (SST-2M) and then to the realization of a mini-array composed of a few of these units. The prototype and all the necessary hardware devices are foreseen to be installed at the Serra La Nave Observing Station (Catania, Italy) in 2014. The upcoming data flow will be properly reduced by dedicated (online and offline) analysis pipelines aimed at providing robust and reliable scientific results (signal detection, sky maps, spectra and light curves) from the ASTRI silicon photo-multipliers camera raw data. Furthermore, a flexible archiving system has being conceived for the storage of all the acquired ASTRI (scientific, calibration, housekeeping) data at different steps of the data reduction up to the final scientific products. In this contribution we present the data acquisition, the analysis pipeline and the archive architecture that will be in use for the ASTRI SST prototype. In addition, the generalization of the data management system to the case of a mini-array of ASTRI telescopes will be discussed.
A decline and fall in the future of Italian Astronomy?
On May 27th 2010, the Italian astronomical community learned with concern that the National Institute for Astrophysics (INAF) was going to be suppressed, and that its employees were going to be transferred to the National Research Council (CNR). It was not clear if this applied to all employees (i.e. also to researchers hired on short-term contracts), and how this was going to happen in practice. In this letter, we give a brief historical overview of INAF and present a short chronicle of the few eventful days that followed. Starting from this example, we then comment on the current situation and prospects of astronomical research in Italy.
Citizen science, gamification, fotogrammetria per il contrasto al rischio di oblio dei Beni Culturali minori
This article presents the Hego project (HeritageGo) which combine the logic of citizen science and aspects of gamification with the potential of the photogrammetric survey technique. A particular approach for the knowledge of small urban contexts, architectural and archaeological emergencies that conceive an innovative procedure for their valorisation and preservation, through the creation of a social interaction system applied to the survey, with the involvement of voluntary users / players (tourists, students, scholars, associations, etc.).