Alina Mihaela Badescu
A5008328669- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Radio Astronomy Observations and Technology
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Antenna Design and Analysis
- Pulsars and Gravitational Waves Research
- Geophysical Methods and Applications
- Ionosphere and magnetosphere dynamics
- Atmospheric aerosols and clouds
- Wireless Communication Networks Research
- Cosmology and Gravitation Theories
- Astronomical Observations and Instrumentation
- High-Energy Particle Collisions Research
- Soil Moisture and Remote Sensing
- Antenna Design and Optimization
- Radiation Detection and Scintillator Technologies
- Photocathodes and Microchannel Plates
- Energy Harvesting in Wireless Networks
- solar cell performance optimization
- Microwave Engineering and Waveguides
- Advanced Antenna and Metasurface Technologies
Universitatea Națională de Știință și Tehnologie Politehnica București
2015-2024
Institute of Astronomy and Space Physics
2016-2023
Consejo Nacional de Investigaciones Científicas y Técnicas
2016-2023
Universidad Nacional de La Plata
2016-2023
University of Buenos Aires
2016-2023
Instituto de Tecnologías en Detección y Astropartículas
2016-2023
National University of General San Martín
2016-2023
National Technological University
2016-2023
Pierre Auger Observatory
2016-2023
Institute of Scientific and Technical Research for Defense
2016-2023
The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. objectives of Observatory are to probe origin and characteristics rays above $10^{17}$ eV study interactions these, most energetic particles observed nature. design features an array 1660 water-Cherenkov particle detector stations spread over 3000 km$^2$ overlooked by 24 air fluorescence telescopes. In addition, three elevation telescopes overlook 23.5 km$^2$,...
We report a study of the distributions depth maximum, ${X}_{\mathrm{max}}$, extensive air-shower profiles with energies above $1{0}^{17.8}\text{ }\text{ }\mathrm{eV}$ as observed fluorescence telescopes Pierre Auger Observatory. The analysis method for selecting data sample minimal sampling bias is described in detail well experimental cross-checks and systematic uncertainties. Furthermore, we discuss detector acceptance resolution ${X}_{\mathrm{max}}$ measurement provide parametrizations...
Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come studying distribution of arrival directions. Using 3 × 104 cosmic with above 8 1018 electron volts, recorded Pierre Auger Observatory a total exposure 76,800 km2 sr year, we determined existence anisotropy The anisotropy, detected at more than 5.2σ level significance, can be described by dipole an amplitude [Formula: see text] percent toward right ascension...
We present a combined fit of simple astrophysical model UHECR sources to both the energy spectrum and mass composition data measured by Pierre Auger Observatory. The has been performed for energies above 5 ⋅ 1018 eV, i.e. region all-particle so-called "ankle" feature. we adopted consists identical uniformly distributed in comoving volume, where nuclei are accelerated through rigidity-dependent mechanism. results suggest characterized relatively low maximum injection energies, hard spectra...
Using the data taken at Pierre Auger Observatory between December 2004 and 2012, we have examined implications of distributions depths atmospheric shower maximum (Xmax), using a hybrid technique, for composition hadronic interaction models. We do this by fitting with predictions from variety models variations in primary cosmic rays examining quality fit. Regardless what model is assumed, find that our are not well described mix protons iron nuclei over most energy range. Acceptable fits can...
We present the first hybrid measurement of average muon number in air showers at ultra-high energies, initiated by cosmic rays with zenith angles between $62^\circ$ and $80^\circ$. The is based on 174 events recorded simultaneously Surface Detector array Fluorescence Pierre Auger Observatory. for each shower derived scaling a simulated reference profile lateral density distribution ground until it fits data. A $10^{19}$~eV angle $67^\circ$, which arrives an altitude 1450 m above sea level,...
Abstract A new analysis of the data set from Pierre Auger Observatory provides evidence for anisotropy in arrival directions ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative excess arrivals strong, nearby sources. The consist 5514 events above with zenith angles up to 80° recorded before 2017 April 30. Sky models have been created two distinct populations extragalactic gamma-ray emitters: active galactic nuclei second catalog hard Fermi -LAT sources (2FHL)...
Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on absolute calibration, and apply it events with primary 6–16 EeV (ECM=110–170 TeV), whose longitudinal development lateral distribution were simultaneously measured by Pierre Auger Observatory. The average shower is 1.33±0.16 (1.61±0.21) times larger than predicted using leading LHC-tuned EPOS-LHC...
We analyze the distribution of arrival directions ultra-high energy cosmic rays recorded at Pierre Auger Observatory in 10 years operation. The data set, about three times larger than that used earlier studies, includes with zenith angles up to $80^\circ$, thus covering from $-90^\circ$ $+45^\circ$ declination. After updating fraction events correlating active galactic nuclei (AGNs) V\'eron-Cetty and V\'eron catalog, we subject energies excess 40 EeV different tests for anisotropy. search...
We report a measurement of the energy spectrum cosmic rays for energies above 2.5×1018 eV based on 215,030 events recorded with zenith angles below 60°. A key feature work is that estimates are independent assumptions about unknown hadronic physics or primary mass composition. The most precise made hitherto accumulated exposure being so large measurements flux dominated by systematic uncertainties except at 5×1019 eV. principal conclusions (1) flattening near 5×1018 eV, so-called "ankle,"...
Abstract In this work we present the interpretation of energy spectrum and mass composition data as measured by Pierre Auger Collaboration above 6 × 10 17 eV. We use an astrophysical model with two extragalactic source populations to hardening cosmic-ray flux at around 5 18 eV (the so-called “ankle” feature) a transition between these components. find our be well reproduced if sources ankle emit mixed hard low rigidity cutoff. The component below is required have very soft mix protons...
Abstract The combined fit of the measured energy spectrum and shower maximum depth distributions ultra-high-energy cosmic rays is known to constrain parameters astrophysical models with homogeneous source distributions. Studies distribution cosmic-ray arrival directions show a better agreement in which fraction flux non-isotropic associated nearby radio galaxy Centaurus A or catalogs such as that starburst galaxies. Here, we present novel combination both analyses by simultaneous directions,...
Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable Surface Detector array of Pierre Auger Observatory. We report here on searches through data from January 2004 until 20 June 2013. No neutrino candidates were found, yielding a limit to diffuse ultra-high energy neutrinos that challenges Waxman-Bahcall bound predictions. Neutrino identification is attempted using broad time-structure signals expected SD stations, efficiently done for all flavors interacting...
We report a measurement of the energy spectrum cosmic rays above 2.5×1018 eV based on 215 030 events. New results are presented: at about 1.3×1019 eV, spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving 5.1±0.3(stat)±0.1(syst) beyond 5×1019 while no significant dependence features declination is seen in accessible range. These can be reproduced models with energy-dependent mass composition. The density 5×1018 [5.66±0.03(stat)±1.40(syst)]×1053 erg...
Neutrinos with energies above $10^{17}$ eV are detectable the Surface Detector Array of Pierre Auger Observatory. The identification is efficiently performed for neutrinos all flavors interacting in atmosphere at large zenith angles, as well Earth-skimming $\tau$ nearly tangential trajectories relative to earth. No neutrino candidates were found $\sim\,14.7$ years data taken up 31 August 2018. This leads restrictive upper bounds on their flux. $90\%$ C.L. single-flavor limit diffuse flux...
The Pierre Auger Observatory is exploring the potential of radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. Engineering Radio Array (AERA) addresses both technological and scientific aspects technique. A first phase AERA has been operating since September 2010 with detector stations observing signals at frequencies between 30 80 MHz. In this paper we present comparative studies identify optimize antenna design for final configuration...
The Auger Engineering Radio Array (AERA) is part of the Pierre Observatory and used to detect radio emission cosmic-ray air showers. These observations are compared data surface detector stations Observatory, which provide well-calibrated information on energies arrival directions. response in 30--80 MHz regime has been thoroughly calibrated enable reconstruction incoming electric field. For latter, energy deposit per area determined from pulses at each observer position interpolated using a...
We present a new method for probing the hadronic interaction models at ultrahigh energy and extracting details about mass composition. This is done using time profiles of signals recorded with water-Cherenkov detectors Pierre Auger Observatory. The arise from mix muon electromagnetic components air showers. Using risetimes signals, we define parameter, which use to compare our observations predictions simulations. find, first, inconsistencies between data over greater range substantially...
The emission of radio waves from air showers has been attributed to the so-called geomagnetic process. At frequencies around 50 MHz this process leads coherent radiation which can be observed with rather simple setups. direction electric field induced by depends only on local magnetic vector and incoming shower. We report measurements where, in addition component, another component that cannot described data provide strong evidence other is polarized radially respect shower axis, agreement...
We present a detailed study of the large-scale anisotropies cosmic rays with energies above 4 EeV measured using Pierre Auger Observatory. For energy bins [4,8] and $E\geq 8$ EeV, most significant signal is dipolar modulation in right ascension at 8 as previously reported. In this paper we further scrutinize highest-energy bin by splitting it into three ranges. find that amplitude dipole increases EeV. The growth can be fitted power law index $\beta=0.79\pm 0.19$. directions dipoles are...
We measure the energy emitted by extensive air showers in form of radio emission frequency range from 30 to 80 MHz. Exploiting accurate scale Pierre Auger Observatory, we obtain a radiation 15.8 \pm 0.7 (stat) 6.7 (sys) MeV for cosmic rays with an 1 EeV arriving perpendicularly geomagnetic field 0.24 G, scaling quadratically cosmic-ray energy. A comparison predictions state-of-the-art first-principle calculations shows agreement our measurement. The provides direct access calorimetric...
The surface detector array of the Pierre Auger Observatory provides information about longitudinal development muonic component extensive air showers. Using timing from flash analog-to-digital converter traces detectors far shower core, it is possible to reconstruct a muon production depth distribution. We characterize goodness this reconstruction for zenith angles around 60 deg. and different energies primary particle. From these distributions we define X(mu)max as along axis where muons...
We report a first measurement for ultra-high energy cosmic rays of the correlation between depth shower maximum and signal in water Cherenkov stations air-showers registered simultaneously by fluorescence surface detectors Pierre Auger Observatory. Such is unique feature hybrid air-shower observatory with sensitivity to both electromagnetic muonic components. It allows an accurate determination spread primary masses cosmic-ray flux. Up till now, constraints on have been dominated systematic...
The Pierre Auger Observatory has begun a major Upgrade of its already impressive capabilities, with an emphasis on improved mass composition determination using the surface detectors Observatory. Known as AugerPrime, upgrade will include new 4 m$^2$ plastic scintillator top all 1660 water-Cherenkov detectors, updated and more flexible detector electronics, large array buried muon extended duty cycle for operations fluorescence detectors. This Preliminary Design Report was produced by...