Multifrequency JVLA observations of the X-shaped radio galaxy in Abell 3670

Context. X-shaped radio galaxies (XRGs) exhibit a pair of bright primary lobes and a pair of weak secondary lobes (wings), which are oriented with an angle that gives the structure a cross-like shape. Though several theoretical models have been proposed to explain their origin, there is currently not a general consensus on a formation scenario. Aims. We analysed new multifrequency Karl G. Jansky Very Large Array (JVLA) radio data at 1.5, 5.5, 6, and 9 GHz of the candidate XRG in Abell 3670 (A3670) in order to characterise and classify it for the first time and to investigate its origin. Methods. We produced flux, spectral index, and radiative age maps of A3670 by means of the new radio data. We investigated the connection between the radio galaxy and its host, a brightest cluster galaxy (BCG) with two optical nuclei classified as a dumbbell galaxy. Finally we discussed the literature models and compared them to the observed properties of A3670. Results. We classify A3670 as a Fanaroff-Riley I-type XRG and measured a 1.4 GHz radio power of 1.7 x 10^25 W Hz-1. By estimating the radiative age of the various source components, we find that the wings are 20 Myr older than the lobes. We verified that the lobes and wings are aligned with the major and minor axes of the optical galaxy, respectively, and we estimated a black hole mass of 10^9 Msun , which is in agreement with the typical properties of the XRGs. Conclusions. Among the discussed scenarios, the jet-shell interaction model may best reproduce the observed properties of A3670. The gas of a stellar shell is responsible for the deflection of the jets, thus forming the wings. The presence of stellar shells in A3670 is plausible, but it needs further optical observations to be confirmed.Comment: 11 pages, 19 figures grouped in 8, in press on Astronomy&Astrophysic

Radio-optical properties of extragalactic populations in the VIPERS Survey

The radio and optical characteristics of faint radio sources are investigated thanks to the VIPERS spectroscopic and photometric data, and radio data from the VLA FIRST survey at 1.4 GHz

Realizzazione di un nuovo sito web per l’INAF - Istituto di Radioastronomia

Questo report illustra l'attivita` del gruppo di lavoro incaricato della progettazione e sviluppo del nuovo sito web dell'INAF - Istituto di Radioastronomia. L'utilizzo di tecnologie di sviluppo web basate su CMS ha consentito di superare le difficolta` nell'aggiornamento e gestione del precedente sito basato su pagine html statiche. Con il nuovo approccio si è ottenuto da un lato un notevole miglioramento dell'aspetto grafico e della coerenza tra le pagine, dall’altro una notevole semplificazione nella produzione e nell’aggiornamento delle pagine stesse. Cio` consentira` ai diversi gruppi di ricerca, servizi e uffici di farsi carico delle pagine di competenza e di poter facilmente apportare modifiche ai contenuti via via che queste si renderanno necessarie, garantendo allo stesso tempo una maggiore sicurezza informatica. Nel report vengono descritte le varie fasi dell'attivita` del gruppo di lavoro: dalla iniziale identificazione delle linee guida e progettazione di struttura e contenuti, sino alla realizzazione vera e propria delle pagine web e ai successivi step di verifica conclusi con la pubblicazione online del sito

A public data archive for the Italian radio telescopes

The amount of data delivered by modern instrumentation and observing techniques is bringing radio astronomy in the era of Big Data, and the nowadays widely adopted Open Data policies allow free and open access to data from many radio astronomy facilities. A fundamental ingredient to enable Open Science in the radio astronomical community and to engage also public participation (the so called Citizen Science) is thus the availability of public archives in which data can be accessed and searched with modern software tools. A web-based, VO-compliant public archive has been built to host data from the Italian radio telescopes managed by the National Institute for Astrophysics (INAF). The archive main features consist in the capability to handle the various types of data coming from the different observing instrumentation at the telescopes; the adoption of a policy to guarantee the data proprietary period; the accessibility of data through a web interface and the adoption of VO standards to allow for successful scientific exploitation of the archive itself in the data mining era. We present the progress status of the public Data Archive for the Italian radio telescopes being developed to provide the international community with a state-of-the-art archive for radio astronomical data

Radio data archiving system

Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly

Dish Washer: a Software Tool for RFI Mitigation in Single-dish Radio Astronomical Observations

Radio Frequency Interference is one of the most pressing problems in cm-wavelength world-wide radio astronomy, in particular for single-dish telescope observations. Due to both the increasing abundance of man-made interfering signals and the improved performance of the telescope instrumentation, the impact of RFI at the Italian radio telescope sites is now a major concern, thus strategies for its mitigation are to be applied. Dish Washer is a new software tool for the detection and flagging of RFI in signals collected by single-dish radio telescopes. It implements both interactive flagging and some level of automatic detection of RFI through dedicated algorithms. Its first public release is foreseen as free software under the GNU General Public License

Report attività di didattica e divulgazione INAF-IRA 2021

In questo documento sono riportate e descritte le attività di Didattica e Divulgazione (D&D) dell'INAF - Istituto di Radioastronomia svolte nel 2021. Le attività includono la progettazione di contenuti, la curatela e gestione del Centro Visite “Marcello Ceccarelli”, l’organizzazione di eventi in collaborazione con enti territoriali, nazionali e internazionali, la gestione amministrativa e finanziaria, la formazione di studenti e giovani collaboratori e la gestione degli accessi esterni per riprese video e servizi fotografici presso la Stazione Radioastronomica di Medicina (BO)

Towards coordinated site monitoring and common strategies for mitigation of Radio Frequency Interference at the Italian radio telescopes

We present a project to implement a national common strategy for the mitigation of the steadily deteriorating Radio Frequency Interference (RFI) situation at the Italian radio telescopes. The project involves the Medicina, Noto, and Sardinia dish antennas and comprised the definition of a coordinated plan for site monitoring as well as the implementation of state-of-the-art hardware and software tools for RFI mitigation. Coordinated monitoring of frequency bands up to 40 GHz has been performed by means of continuous observations and dedicated measurement campaigns with fixed stations and mobile laboratories. Measurements were executed on the frequency bands allocated to the radio astronomy and space research service for shared or exclusive use and on the wider ones employed by the current and under-development receivers at the telescopes. Results of the monitoring campaigns provide a reference scenario useful to evaluate the evolution of the interference situation at the telescopes sites and a case series to test and improve the hardware and software tools we conceived to counteract radio frequency interference. We developed a multi-purpose digital backend for high spectral and time resolution observations over large bandwidths. Observational results demonstrate that the spectrometer robustness and sensitivity enable the efficient detection and analysis of interfering signals in radio astronomical data. A prototype off-line software tool for interference detection and flagging has been also implemented. This package is capable to handle the huge amount of data delivered by the most modern instrumentation on board of the Italian radio telecsopes, like dense focal plane arrays, and its modularity easen the integration of new algorithms and the re-usability in different contexts or telescopes.Comment: 39 pages, 10 Figures and 7 Tables. INAF Technical Report n. 149 (2022). http://hdl.handle.net/20.500.12386/3208

REPORT 2022 DELLE ATTIVITÀ DI DIDATTICA E DIVULGAZIONE INAF - IRA

L'Istituto di Radioastronomia (IRA) dell’Istituto Nazionale di Astrofisica (INAF) è impegnato nella diffusione delle proprie attività presso le scuole e il pubblico, attraverso le visite guidate alle Stazioni Radioastronomiche di Medicina (BO) e Noto (SR) e la partecipazione alla realizzazione di mostre, eventi, ecc. Le attività di Didattica e Divulgazione IRA includono la progettazione di contenuti, la curatela e gestione del Centro Visite “Marcello Ceccarelli”, l’organizzazione di eventi in collaborazione con enti territoriali, nazionali e internazionali, la gestione amministrativa e finanziaria, la formazione di nuovo personale. In questo documento sono riportate le attività svolte nel 2022