A5034118511- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Galaxies: Formation, Evolution, Phenomena
- Particle Accelerators and Free-Electron Lasers
- Neutrino Physics Research
- Astronomical Observations and Instrumentation
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Particle physics theoretical and experimental studies
- Superconducting Materials and Applications
- Astronomy and Astrophysical Research
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Computational Physics and Python Applications
- Gyrotron and Vacuum Electronics Research
- Experimental and Theoretical Physics Studies
Agenzia Spaziale Italiana
2020-2021
Istituto di Radioastronomia di Bologna
2021
University of Łódź
2021
Kyoto University
2021
Turku Centre for Computer Science
2021
University of Turku
2021
Instituto de Astrofísica de Andalucía
2021
Ruhr University Bochum
2021
Boston University
2021
Max Planck Institute for Radio Astronomy
2017-2020
The fourth catalog of active galactic nuclei (AGNs) detected by the Fermi Gamma-ray Space Telescope Large Area (4LAC) between 2008 August 4 and 2016 2 contains 2863 objects located at high Galactic latitudes (|b|>10{\deg}). It includes 85% more sources than previous 3LAC based on years data. AGNs represent least 79% high-latitude in Fermi-Large Source Catalog (4FGL), which covers energy range from 50 MeV to 1 TeV. In addition, 344 gamma-ray are found low latitudes. Most 4LAC blazars (98%),...
Motivated by the identification of blazar TXS 0506+056 as first promising high-energy neutrino counterpart candidate, we search for additional blazars candidates among Fermi-LAT detected blazars. We investigate multi-wavelength behavior from radio to GeV gamma rays found be in spatial coincidence with single neutrinos and lower-energy flare candidates. In addition, compare average gamma-ray emission potential neutrino-emitting sources entire sample find that are statistically compatible both...
Aims . In the framework of multi-wavelength and very long baseline interferometry (VLBI) monitoring program TANAMI (Tracking Active Nuclei with Austral Milliarcsecond Interferometry), we study evolution parsec-scale radio emission in galaxies southern hemisphere their relationship to γ -ray properties sources. Our investigates systematically, for first time, between two energy regimes galaxies. this paper, focus on Fermi -LAT-detected Methods The monitors a large sample radio-loud AGN at 8.4...
High-redshift ($z>2$) blazars are the most powerful members of blazar family. Yet, only a handful them have both X-ray and $\gamma$-ray detection, thereby making it difficult to characterize energetics luminous jets. Here, we report, for first time, Fermi-Large Area Telescope detection significant emission from high-redshift DA 193 ($z=2.363$). Its time-averaged spectrum is soft ($\gamma$-ray photon index = $2.9\pm0.1$) together with relatively flat hard (14$-$195 keV $1.5\pm0.4$), presents...
In March 2018, Mukherjee (2018) reported the detection by VERITAS of very-high-energy emission (VHE; > 100 GeV) from 3C 264. This is sixth, and second most distant, radio galaxy ever detected in TeV regime. this article we present a X-ray analysis jet We determine main physical parameters parsec-scale flow explore implications inferred kinematic structure for radiative models gamma-ray emitting jet. The data set comprised VLBI observations at 15 GHz MOJAVE program, cover time period ~2...
In this paper, we characterize the first $\gamma$-ray flaring episode of FSRQ PKS 0346-27 (z=0.991), as revealed by Fermi-LAT monitoring data, and concurrent multi-wavelength variability observed from radio through X-rays. The quasi-simultaneous coverage allowed us to construct time-resolved spectral energy distributions (SEDs). entered an elevated activity state starting beginning 2018. high-state continued throughout year, displaying highest fluxes in May We find evidence short-time scale...
The $γ$-ray production mechanism and its localization in blazars are still a matter of debate. main goal this paper is to constrain the location high-energy emission blazar TXS 2013+370 study physical geometrical properties inner jet region on sub-pc scales. VLBI observations at 86 GHz space-VLBI 22 allowed us image base with an angular resolution $\sim$0.4 pc. By employing CLEAN imaging Gaussian model-fitting, we performed thorough kinematic analysis, which provided estimates speed,...
PKS 1718$-$649 is one of the closest and most comprehensively studied candidates a young active galactic nucleus (AGN) that still embedded in its optical host galaxy. The compact radio structure, with maximal extent few parsecs, makes it member group symmetric objects (CSO). Its environment imposes turnover synchrotron spectrum towards lower frequencies, also classifying as gigahertz-peaked (GPS) source. close proximity has allowed first detection extended X-ray emission GPS/CSO source...
TANAMI is a multiwavelength program monitoring active galactic nuclei (AGN) south of -30deg declination including high-resolution Very Long Baseline Interferometry (VLBI) imaging, radio, optical/UV, X-ray and gamma-ray studies. We have previously published first-epoch 8.4GHz VLBI images the parsec-scale structure initial sample. In this paper, we present 39 additional sources. The full sample comprises most radio- brightest AGN in southern quarter sky, overlapping with region from which...
Following our study of the radio and high-energy properties $\gamma$-ray-emitting galaxies, here we investigate kinematic spectral parsec-scale jets galaxies that have not yet been detected by Fermi-LAT. We take advantage regular VLBI observations provided TANAMI monitoring program, explore six $\gamma$-ray-faint galaxies. include publicly available kinematics $\gamma$-ray-quiet monitored MOJAVE program perform a Fermi-LAT analysis, deriving upper limits. combine these results with those...
We present the results of a study aimed at evaluating impact CTA in high-energy studies radio galaxies, and elusive class very-high-energy emitters, which counts only 5 detections TeV band moment. perform simulations observations Fermi-LAT galaxies using ctools package. Our indicate that 7 out 12 local (z<0.1) candidates should be detected 50 hours integration time, if Fermi power-laws are smoothly connected. If spectrum drops off band, number progressively decreases shifting power-law...
This research was funded in part by NASA through Fermi Guest Investigator grants NNH10ZDA001N, NNH12ZDA001N, and NNH13ZDA001N-FERMI (proposal numbers 41213, 61089, 71326, respectively). supported an appointment to the Postdoctoral Program at Goddard Space Flight Center, administered Universities Research Association a contract with NASA. This work performed in part under DOE Contract DE-AC02-76SF00515.