Nectaria Gizani
A5006673994- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- Astronomy and Astrophysical Research
- Space Science and Extraterrestrial Life
- Neutrino Physics Research
- Astronomical Observations and Instrumentation
- Dark Matter and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Environmental Education and Sustainability
- Radio Wave Propagation Studies
- Planetary Science and Exploration
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Particle accelerators and beam dynamics
- Solar Radiation and Photovoltaics
- Climate variability and models
- Space exploration and regulation
- Soil Moisture and Remote Sensing
Hellenic Open University
2011-2023
University of California, Berkeley
2018-2020
National Observatory of Athens
2004-2005
University of Coimbra
2005
Institute of Astronomy and Astrophysics, Academia Sinica
2005
SKA Observatory
1996-2004
University of Manchester
1996-2004
University of Lisbon
2001-2003
Institute of Astrophysics and Space Sciences
2001-2003
University of Ioannina
1999-2002
The main objectives of the KM3NeT Collaboration are (i) discovery and subsequent observation high-energy neutrino sources in Universe (ii) determination mass hierarchy neutrinos. These strongly motivated by two recent important discoveries, namely: (1) astrophysical signal reported IceCube (2) sizable contribution electron neutrinos to third eigenstate as Daya Bay, Reno others. To meet these objectives, plans build a new Research Infrastructure consisting network deep-sea telescopes...
We report the first detections of repeating fast radio burst source FRB 121102 above 5.2 GHz. Observations were performed using 4$-$8 GHz receiver Robert C. Byrd Green Bank Telescope with Breakthrough Listen digital backend. present spectral, temporal and polarization properties 21 bursts detected within 60 minutes a total 6-hour observations. These observations comprise highest density yet reported in literature, 18 being 30 minutes. A few clearly show sub-structures distinct spectral...
The first prototype of a photo-detection unit the future KM3NeT neutrino telescope has been deployed in deep waters Mediterranean Sea. This digital optical module novel design with very large photocathode area segmented by use 31 three inch photomultiplier tubes. It integrated ANTARES detector for in-situ testing and validation. paper reports on months data taking rate measurements. analysis results highlight capabilities new terms background suppression signal recognition. directionality...
Breakthrough Listen is the most comprehensive and sensitive search for extraterrestrial intelligence (SETI) to date, employing a collection of international observational facilities including both radio optical telescopes. During first three years program, thousands targets have been observed with Green Bank Telescope (GBT), Parkes Automated Planet Finder. At GBT Parkes, observations performed ranging from 700 MHz 26 GHz, raw data volumes averaging over 1PB / day. A pseudo-real time software...
A prototype detection unit of the KM3NeT deep-sea neutrino telescope has been installed at 3500m depth 80 km offshore Italian coast. in its final configuration will contain several hundreds units. Each is a mechanical structure anchored to sea floor, held vertical by submerged buoy and supporting optical modules for Cherenkov light emitted charged secondary particles emerging from interactions. This string implements three with 31 photomultiplier tubes each. These were developed...
Here, we report on the detection and verification of Fast Radio Burst FRB 180301, which occurred UTC 2018 March 1 during Breakthrough Listen observations with Parkes telescope. Full-polarization voltage data were captured--a first for non-repeating FRBs--allowing coherent de-dispersion additional tests. The coherently de-dispersed dynamic spectrum 180301 shows complex, polarized frequency structure over a small fractional bandwidth. As was detected close to geosynchronous satellite band time...
Breakthrough Listen is a ten-year initiative to search for signatures of technologies created by extraterrestrial civilizations at radio and optical wavelengths. Here, we detail the digital data recording system deployed observations 64-m aperture CSIRO Parkes Telescope in New South Wales, Australia. The currently implements two modes: dual-polarization, 1.125 GHz bandwidth mode single beam observations, 26-input, 308-MHz 21-cm multibeam receiver. also designed support 3 single-beam...
Breakthrough Listen (BL) is a ten-year initiative to search for signatures of technologically capable life beyond Earth via radio and optical observations the local Universe. A core part BL program comprehensive survey 1702 nearby stars at wavelengths (1-10 GHz). Here, we report on with 64-m CSIRO Parkes telescope in New South Wales, Australia, 100-m Robert C. Byrd Green Bank West Virginia, USA. Over 2016 January 2019 March, sample 1138 was observed using 1.10-1.90 GHz 1.80-2.80 receivers,...
We have mapped the powerful radio galaxy Hercules A at six frequencies spanning 1295 to 8440 MHz using Very Large Array (VLA) in all four configurations. Here we discuss structure revealed total intensity, spectral index, polarization, and projected magnetic field.
Studying atmospheric neutrino oscillations in the few-GeV range with a multi-megaton detector promises to determine mass hierarchy. This is main science goal pursued by future KM3NeT/ORCA water Cherenkov Mediterranean Sea. In this paper, processes that limit obtainable resolution both energy and direction charged-current events ORCA are investigated. These include composition of hadronic fragmentation products, subsequent particle propagation photon-sampling fraction detector. GEANT...
The prominent radio source Hercules A features complex structures in its lobes. Although it is one of the most comprehensively studied sources sky, origin ring lobes remains an open question. We present first sub-arcsecond angular resolution images at low frequencies (<300 MHz) A, made with International LOFAR Telescope. With addition data from Karl G. Jansky Very Large Array, we mapped structure 144 MHz to 7 GHz. explore rings within and test whether their properties are best described by a...
We have conducted a search for radio emission consistent with an artificial source targeting 1I/'Oumuamua the Robert C. Byrd Green Bank Telescope (GBT) between 1.1 and 11.6 GHz. searched data narrowband signals found none. Given close proximity to this interstellar object, we can place limits putative transmitters extremely low power (0.08 W).
Abstract The discovery of ubiquitous habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, has ushered a renaissance the search for extraterrestrial intelligence (SETI). Large scale SETI activities are now underway at numerous international facilities. Five-hundred-meter Aperture Spherical radio Telescope (FAST) is largest single-aperture telescope world, well positioned to conduct sensitive searches emission indicative...
Indicators are used in almost every scientific field to quantify and/or record follow the evolution of a specific parameter. Environmental indicators related environment quality and specifically monitor measure environmental performance. They can be categorized into specific, composite personal indicators. A review literature presented here. Personal include attitudes behaviours citizens towards issues. The main reported are: New Paradigm Scale, Attitude Inventory, General Ecological...
Indicators are used in almost every scientific field to quantify and/or record follow the evolution of a specific parameter. Environmental indicators related environment quality and specifically monitor measure environmental performance. They can be categorized into specific, composite personal indicators. A review literature presented here. Specific include natural or anthropogenic environment. The for mainly climate change, reduction ozone layer, air quality, water forest resources,...
We have made X-ray observations of the radio galaxy 3C 388 with ROSAT HRI, resolving thermal gas that confines lobes this powerful (FR II) source. The pressure is substantially higher than minimum pressures in lobes, implying latter an underestimate by order magnitude or more. discuss how can be reconciled recent find inverse-Compton emission from at level predicted conventional minimum-energy arguments. suggest excess due to low-energy electrons and positrons and/or protons, so magnetic...
The discovery of the ubiquity habitable extrasolar planets, combined with revolutionary advances in instrumentation and observational capabilities, have ushered a renaissance millenia-old quest to answer our most profound question about Universe place within it - Are we alone? Breakthrough Listen Initiative, announced July 2015 as 10-year 100M USD program, is comprehensive effort history quantify distribution advanced, technologically capable life universe. In this white paper, outline...
Boyajian' s Star (KIC 8462852) has received significant attention due to its unusual periodic brightness fluctuations detected by the Kepler Spacecraft and subsequent ground based observations. Possible explanations for dips in photometric measurements include interstellar or circumstellar dust, it been speculated that an artificial megastructure could be responsible. We analyze 177 high-resolution spectra of Boyajian's effort detect potential laser signals from extraterrestrial...
Extragalactic jets are generated as bipolar outflows at the nuclei of active galaxies. Depending on their morphology, they classified Fanaroff-Riley type I (centre-brightened) and II (edge-brightened) radio jets. However, this division is not sharp observations these sources large scales often show intermediate jet morphologies or even hybrid with a FRI one side FRII other. A good example galaxy that difficult to classify Hercules~A. This source shows bright lobes (a common feature jets)...
Indicators are used in almost every scientific field to quantify and/or record follow the evolution of a specific parameter. Environmental indicators related environment quality and specifically monitor measure environmental performance. They can be categorized into specific, composite personal indicators. A review literature presented here. Composite include coming from synthesis or cover relationships between economic social sectors. The main reported are: Sustainable Development Goals...
We have made ROSAT Position Sensitive Proportional Counter (PSPC) and High Resolution Imager (HRI) X-ray observations to study the intracluster gas surrounding powerful radio source Hercules A. The cluster is luminous in X-rays (Lbol= 4.8 × 1037 W), although apparently poor optical galaxies, host of central dominating galaxy cluster. azimuthally averaged surface brightness profile well fitted by a modified King (β) model, with core radius rc= 121 ± 10 kpc β= 0.74 0.03, but elongated parallel...
The KM3NeT research infrastructure, currently under construction in the Mediterranean Sea, will host neutrino telescopes for identification of sources Universe and studies mass hierarchy. These house hundreds thousands photomultiplier tubes that have to be operated a stable reliable fashion. In this context, stability dark counts has been investigated with negative high voltage on photocathode held insulating support structures made 3D printed nylon material. Small gaps between rigid...