G. La Mura
A5053034688- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Radio Astronomy Observations and Technology
- Dark Matter and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Particle Accelerators and Free-Electron Lasers
- Particle physics theoretical and experimental studies
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Computational Physics and Python Applications
- Scientific Measurement and Uncertainty Evaluation
- Laser-induced spectroscopy and plasma
- Cosmology and Gravitation Theories
- Adaptive optics and wavefront sensing
- Radiation Detection and Scintillator Technologies
- Photonic Crystal and Fiber Optics
LIP - Laboratory of Instrumentation and Experimental Particle Physics
2019-2024
Osservatorio Astronomico di Cagliari
2023-2024
National Institute for Astrophysics
2023
Campbell Collaboration
2021
University of Padua
2009-2020
Osservatorio Astronomico di Padova
2007-2018
Guangzhou University
2018
Istituto Nazionale di Fisica Nucleare
2018
Istituto Nazionale di Fisica Nucleare, Sezione di Padova
2018
University of Turku
2018
We present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in 100 MeV–300 GeV range. Based on first 4 yr science data from Gamma-ray Space mission, it is deepest yet this energy Relative to Second LAT catalog, 3FGL incorporates twice as much data, well a number analysis improvements, including improved calibrations at event reconstruction level, an updated model for Galactic diffuse γ-ray emission, refined procedure detection, and methods associating with...
The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It based on (3FGL) sources between 100 MeV and 300 GeV with a Test Statistic (TS) greater than 25, 2008 August 4 2012 July 31. 3LAC includes 1591 AGNs located at high Galactic latitudes (|b|>10{\deg}), 71% increase over second 2 years data. There are 28 duplicate associations, thus 1563 2192 high-latitude gamma-ray 3FGL AGNs. Most them (98%) blazars. About half newly blazars unknown type, i.e.,...
Abstract The region around the Galactic Center (GC) is now well established to be brighter at energies of a few GeV than what expected from conventional models diffuse gamma-ray emission and catalogs known sources. We study excess using 6.5 yr data Fermi Large Area Telescope. characterize uncertainty GC spectrum morphology due uncertainties in cosmic-ray source distributions propagation, distribution interstellar gas Milky Way, potential contribution bubbles. also evaluate properties...
We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in first 7 years data using Pass 8 event-level analysis. This is Third Catalog Hard Fermi-LAT Sources (3FHL), containing 1556 objects characterized - 2 TeV energy range. The sensitivity and angular resolution are improved factors 3 relative to previous LAT at same energies (1FHL). vast majority (79%) associated with extragalactic counterparts other wavelengths, including 16 located very high...
We present a catalog of sources detected above 50 GeV by the {\it Fermi}-Large Area Telescope (LAT) in 80 months data. The newly delivered Pass 8 event-level analysis allows detection and characterization GeV--2 TeV energy range. In this band, Fermi}-LAT has 360 sources, which constitute second hard (2FHL). improved angular resolution enables precise localization point ($\sim$1.7$'$ radius at 68 % C.~L.) spatially extended sources. find that 86 can be associated with counterparts other...
On 2015 June 16, Fermi-LAT observed a giant outburst from the flat spectrum radio quasar 3C 279 with peak $>100$ MeV flux of $\sim3.6\times10^{-5}\;{\rm photons}\;{\rm cm}^{-2}\;{\rm s}^{-1}$ averaged over orbital period intervals. It is historically highest $\gamma$-ray source including past EGRET observations, isotropic luminosity reaching $\sim10^{49}\;{\rm erg}\;{\rm s}^{-1}$. During outburst, Fermi spacecraft, which has an 95.4 min, was operated in special pointing mode to optimize...
We present a measurement of the cosmic-ray electron+positron spectrum between 7 GeV and 2 TeV performed with almost seven years data collected Fermi Large Area Telescope. find that is well fit by broken power law break energy at about 50 GeV. Above GeV, described single spectral index $3.07 \pm 0.02 \; (\text{stat+syst}) 0.04 (\text{energy measurement})$. An exponential cutoff lower than 1.8 excluded 95\% CL.
We have conducted a multiwavelength survey of 42 radio loud narrow-1ine Seyfert 1 galaxies (RLNLS1s), selected by searching among all the known sources this type and omitting those with steep spectra. analyse data from frequencies to X-rays, supplement these information available online catalogues literature in order cover full electromagnetic spectrum. This is largest for source. detected 90% X-rays found 17% at γ rays. Extreme variability high energies was also found, down timescales as...
The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This was obtained using 80 months data re-processed with Pass 8, the newest event-level analysis, which significantly improves acceptance and angular resolution instrument. Most 2FHL at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for first time, source count distribution, dN/dS, extragalactic γ-ray E>50 find that it is...
Abstract The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in Milky Way (MW) other, external, star-forming galaxies. Using 2 yr observations with LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit been derived other nearby M33. We revisited emission direction M33 using more than 7 LAT Pass 8 data energy range <?CDATA $0.1\mbox{--}100\,\mathrm{GeV}$?> <mml:math...
We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample 296 NLS1s at redshift between 0.028 and 0.345, extracted from Sloan Digital Sky Survey (SDSS-DR7) public archive. confirm that are mostly characterized Balmer lines with Lorentzian profiles, lower black hole masses higher Eddington ratios than classic broad-line (BLS1s), but they also appear to be active galactic nuclei (AGNs) contiguous BLS1s sharing them common...
Flat-spectrum radio-loud Narrow-Line Seyfert 1 galaxies (NLS1s) are a recently discovered class of $\gamma$-ray emitting Active Galactic Nuclei (AGN), that exhibit some blazar-like properties which explained with the presence relativistic jet viewed at small angles. When blazars observed larger angles they appear as radio-galaxies, and we expect to observe an analogue parent population for beamed NLS1s. However, number known NLS1s large is not enough. Therefore, tried understand origin this...
ABSTRACT The Fermi Large Area Telescope (LAT) has an instantaneous field of view (FoV) covering <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:mn>1</mml:mn> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:mn>5</mml:mn> </mml:math> the sky and it completes a survey entire in high-energy gamma-rays every 3 hr. It enables searches for transient phenomena over timescales from milliseconds to years. Among these could be...
The detection of high-redshift ($z>$3) blazars enables the study evolution most luminous relativistic jets over cosmic time. More importantly, tend to host massive black holes and can be used constrain space density heavy in early Universe. Here, we report first with \fermi-Large Area Telescope five \gm-ray emitting beyond $z=3.1$, more distant than any previously detected $\gamma$-rays. Among these objects, NVSS J151002+570243 is now known blazar at $z=4.31$. These objects have steeply...
Narrow-line Seyfert 1 galaxies (NLS1s) are an interesting subclass of active galactic nuclei (AGN), which tipically does not exhibit any strong radio emission.Seven percent them, though, radio-loud and often show a flat radio-spectrum (F-NLS1s).This, along to the detection γ-ray emission coming from is usually interpreted as sign relativistic beamed jet oriented line sight.An important aspect these AGN that must be understood nature their parent population, in other words how do they appear...
Abstract We report on the Fermi -LAT detection of high-energy emission from behind-the-limb (BTL) solar flares that occurred 2013 October 11, and 2014 January 6 September 1. The observations are associated with active regions originating behind both eastern western limbs, as determined by STEREO . All three very fast coronal mass ejections (CMEs) strong energetic particle events. present updated localizations >100 MeV photon emission, hard X-ray (HXR) EUV images, broadband spectra 10 keV...
The Fermi-Large Area Telescope (LAT) is currently the most important facility for investigating GeV γ-ray sky. With Fermi-LAT, more than three thousand sources have been discovered so far. 1144 (∼40 per cent) of are active galaxies blazar class, and 573 (∼20 listed as candidate uncertain type (BCU), or without a conclusive classification. We use empirical cumulative distribution functions artificial neural networks fast method screening classification BCUs based on data collected at energies...
The spatial extension of a gamma-ray source is an essential ingredient to determine its spectral properties as well potential multi-wavelength counterpart. capability spatially resolve sources greatly improved by the newly delivered Fermi-Large Area Telescope (LAT) Pass 8 event-level analysis which provides greater acceptance and point spread function, two crucial factors for detection extended sources. Here, we present complete search located within 7 degrees from Galactic plane, using 6...
A citizen science project discovers a new type of gamma-ray millisecond pulsar with no detectable radio pulsations.
We present an analysis of 43 years (1972 to 2015) spectroscopic observations the Seyfert 1 galaxy NGC 5548. This includes 12 new unpublished (2003 2015). compiled about 1600 H$\beta$ spectra and analyzed long-term spectral variations 5100 \AA\ continuum line. Our is based on standard procedures including Lomb-Scargle method, which known be rather limited such heterogeneous data sets, method developed specifically for this project that more robust reveals a $\sim$5700 day periodicity in light...
In the last decade of Active Galactic Nuclei (AGN) monitoring programs, Mets\"ahovi Radio Observatory detected multiple times seven powerful flaring narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz. Several hypotheses have been proposed, but understanding this unique phenomenon is still far. To look case from a different point view, we performed an emission line analysis optical spectra, with aim identifying similarities among sources, that can be in turn possibly tied radio behavior. Our...
Over the last decade of active galactic nucleus (AGN) monitoring programs, Metsähovi Radio Observatory has made multiple detections seven powerful flaring narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz. Several hypotheses have been proposed, but understanding this unique phenomenon is still far away. To look case from a different point view, we performed an emission line analysis optical spectra, with aim identifying similarities among sources, which in turn can possibly be tied radio...
We study the disk emission component hidden in single-peaked Broad Emission Lines (BELs) of Active Galactic Nuclei (AGN). compare observed broad lines from a sample 90 Seyfert 1 spectra taken Sloan Digital Sky Survey with simulated line profiles. consider two-component Line Region (BLR) model where an accretion and surrounding non-disk region isotropic cloud velocities generate BEL The analysis is mainly based measurements full widths (at 10%, 20% 30% maximum intensity) asymmetries Comparing...
Although the properties of narrow-line region (NLR) active galactic nuclei (AGN) have been deeply studied by many authors in past three decades, questions are still open.The main goal this work is to explore NLR Seyfert galaxies collecting a large statistical spectroscopic sample 2 and Intermediate-type having high signal-to-noise ratio order take advantage number emission-lines be accurately measured.2153 521 spectra were selected from Sloan Digital Sky Survey -Data Release 7 (SDSS-DR7)...
In recent years, the old paradigm according to which only high-mass black holes can launch powerful relativistic jets in active galactic nuclei (AGN) has begun crumble. The discovery of $\gamma$-rays coming from narrow-line Seyfert 1 galaxies (NLS1s), usually considered young and growing AGN harboring a central hole with mass typically lower than 10$^8$ M$_\odot$, indicated that also these low-mass produce jets. search for parent population $\gamma$-ray emitting NLS1s revealed their...