Papers by Martina Cardillo
Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)
The ASTRI Mini-Array is an international project to build and operate a facility to study astrono... more The ASTRI Mini-Array is an international project to build and operate a facility to study astronomical sources emitting very high-energy-rays in the 1-200 TeV energy band. It will be an array of nine small-sized (4-m diameter) and large field of view (∼10 •) imaging atmospheric Cherenkov telescopes (IACTs) currently under deployment at the Observatorio del Teide (Tenerife, Spain). Thanks to its expected performance, the ASTRI Mini-Array will be important to perform deep Galactic and extra-galactic-ray observations. In order to achieve the final science products, the high-level scientific analysis needs the Instrument Response Functions (IRFs) and event-lists of data level 3 (DL3) as primary inputs. IRFs are derived from the reduction of suitable Monte Carlo simulations, while the event-lists are achieved from the proper reconstruction and selection of the raw data collected during observations. The IRFs include all needed quantities to properly assess the true spectral and spatial properties of the-ray emitters. The IRFs generation mainly depends on hardware settings or configurations, telescope pointing direction, data-taking conditions (e.g. level of the Night Sky Background, atmospheric transparency, etc.) and analysis methods (e.g. reconstruction methods, cut optimisation criteria, etc.). In this contribution, we describe the tools and methods that are currently implemented in the data-reduction software package of the ASTRI Project to generate DL3 IRFs and event-lists.
Journal of Cosmology and Astroparticle Physics
Recently, the Fermi-LAT gamma-ray satellite has detected six Giant Molecular Clouds (GMCs) locate... more Recently, the Fermi-LAT gamma-ray satellite has detected six Giant Molecular Clouds (GMCs) located in the Gould Belt and the Aquila Rift regions. In half of these objects (Taurus, Orion A, Orion B), the observed gamma-ray spectrum can be explained using the Galactic diffused Cosmic Ray (CR) interactions with the gas environments. In the remaining three GMCs (Rho Oph, Aquila Rift, Cepheus), the origin of the gamma-ray spectrum is still not well established. We use the GEometry ANd Tracking (GEANT4) simulation framework in order to simulate gamma-ray emission due to CR/GMC interaction in these three objects, taking into account the gas density distribution inside the GMCs. We find that propagation of diffused Galactic CRs inside these GMCs can explain the Fermi-LAT detected gamma-ray spectra. Further, our estimated TeV-PeV fluxes are consistent with the HAWC upper limits, available for the Aquila Rift GMC. As last step, we compute the total neutrino flux estimated for these GMCs and c...
Rendiconti Lincei. Scienze Fisiche e Naturali, 2019
AGILE is a space mission of the Italian Space Agency dedicated to X-ray and gamma-ray astrophysic... more AGILE is a space mission of the Italian Space Agency dedicated to X-ray and gamma-ray astrophysics operating since 2007. Since the discovery of gravitational wave (GW) events by the LIGO-Virgo Collaboration (LVC) announced in February 2016, AGILE is playing a very important role in the search for possible X-ray and gamma-ray counterparts. The large fields of view of the gamma-ray and hard X-ray imagers (2.5 sr and 1 sr, respectively) and the current spinning mode allow AGILE to cover at any moment a very large fraction of the sky. We present here an overview of AGILE observations of GW events during the LVC observing periods O1 and O2 which span the time interval September 2015-August 2017. In particular, we focus on the main characteristics of AGILE observations of the events GW150914, GW170104, and GW170817. The latter event is of great relevance being associated with a "kilonova" counterpart: we establish important physical constraints on the possible-ray emission from a magnetar-like remnant in the first ∼ 1000 s following the GW event time. We also present further developments and preliminary results obtained in preparation of the O3 observing run (start in April 2019). AGILE is fully operative in the search for GW event counterparts, and continues to observe the sky in a unique way because of its combination of large field-of-view hard X-ray and gamma-ray detectors.
Proceedings of 37th International Cosmic Ray Conference — PoS(ICRC2021)
Silicon photomultipliers (SiPMs) have become the baseline choice for cameras of the smallsized te... more Silicon photomultipliers (SiPMs) have become the baseline choice for cameras of the smallsized telescopes (SSTs) of the Cherenkov Telescope Array (CTA). On the other hand, SiPMs are relatively new to the field and covering large surfaces and operating at high data rates still are challenges to outperform photomultipliers (PMTs). The higher sensitivity in the near infra-red and longer signals compared to PMTs result in higher night sky background rate for SiPMs. However, the robustness of the SiPMs represents a unique opportunity to ensure long-term operation with low maintenance and better duty cycle than PMTs. The proposed camera for large size telescopes will feature 0.05 • pixels, low power and fast front-end electronics and a fully digital readout. In this work, we present the status of dedicated simulations and data analysis for the performance estimation. The design features and the different strategies identified, so far, to tackle the demanding requirements and the improved performance are described.
Proceedings of 36th International Cosmic Ray Conference — PoS(ICRC2019), 2019
Proceedings of 25th Texas Symposium on Relativistic Astrophysics — PoS(Texas 2010), 2011
The GRID instrument onboard the AGILE satellite detected several Supernova Remnants in the energy... more The GRID instrument onboard the AGILE satellite detected several Supernova Remnants in the energy band E>100 MeV, including the remarkable W28. Here we present an overview of spectral and morphological studies performed for some of them. We show that by combining gamma-ray observations with those at other wavelengths (TeV and CO (J=1->0) molecular line emission), we can constrain the theoretical models for the gamma ray production in SNRs. We show also that models based on the interaction of hadrons with massive molecular clouds can well reproduce the observations, especially in the case of middle-aged SNRs.
Proceedings of 25th Texas Symposium on Relativistic Astrophysics — PoS(Texas 2010), 2011
AGILE pointed the Virgo Region for the first time for 3 weeks, starting from the second half of D... more AGILE pointed the Virgo Region for the first time for 3 weeks, starting from the second half of December 2007. We detected two FSRQ: 3C 273 [1] and 3C 279, and a unidentified gamma ray source: AGLJ 1238+0406. The source is positionally consistent with an AGN of the Sloan Digital Survey, namely SDSS J123932.75+044305 at z=1.76. In the 2 nd edition of the Roma-BZCAT Multi-frequency Catalogue of Blazars [2] the source is associated with a Flat Spectrum Radio Quasar, BZQ 1239+0443. During the AGILE observation, INTEGRAL observed the same field for 600 ksec. IBIS did not detected the source in hard X-ray. OMC instead detected a weak signal from SDSS J123932.75+044305. AGL J1238+0406 has been already detected at low significance by EGRET [3], integrating the whole mission dataset. Then it was detected by FERMI one year after the AGILE pointing of the Virgo field. We report the simultaneous multiwavelength data obtained for the two periods of high gamma ray activity of the source.
The AGILE satellite detects gamma-ray activity from the FSRQ 3C 454.3 after an extended period of... more The AGILE satellite detects gamma-ray activity from the FSRQ 3C 454.3 after an extended period of low flux levels during 2013. The source entered the AGILE Field of View at the end of April, 2014, and an enhanced variable emission above 100 MeV has been detected since May 18th. ..
AGILE is now detecting transient gamma-ray emission above 100 MeV from a source positionally cons... more AGILE is now detecting transient gamma-ray emission above 100 MeV from a source positionally consistent with PKS 1510-089. Integrating from 2014-07-31 00:43 UT to 2014-08-02 02:15 UT, a preliminary maximum likelihood analysis yields a detection above 100 MeV positioned at Galactic coordinates (l,b) = (350.96, 40.12) +/- 0.9 (stat.) +/- 0.1 (syst.)
Astronomy and Astrophysics, 2008
Context. We report the detection by the AGILE (Astro-rivelatore Gamma a Immagini LEggero) satelli... more Context. We report the detection by the AGILE (Astro-rivelatore Gamma a Immagini LEggero) satellite of an intense gamma-ray flare from the source AGL J1511-0909, associated with the powerful quasar PKS 1510-089, during ten days of observations from 23 August to 1 September 2007. Aims. During the observation period, the source was in optical decrease following a flaring event monitored by the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT). The simultaneous gamma-ray, optical, and radio coverage allows us to study the spectral energy distribution and the theoretical models based on the synchrotron and inverse Compton (IC) emission mechanisms. Methods. AGILE observed the source with its two co-aligned imagers, the Gamma-Ray Imaging Detector and the hard X-ray imager Super-AGILE sensitive in the 30 MeV ÷ 50 GeV and 18 ÷ 60 keV bands, respectively. Results. Between 23 and 27 August 2007, AGILE detected gamma-ray emission from PKS 1510-089 when this source was located ∼50 • off-axis, with an average flux of (270 ± 65) × 10 −8 photons cm −2 s −1 for photon energy above 100 MeV. In the following period, 28 August−1 September, after a satellite re-pointing, AGILE detected the source at ∼35 • off-axis, with an average flux (E > 100 MeV) of (195 ± 30) × 10 −8 photons cm −2 s −1. No emission was detected by Super-AGILE, with a 3-σ upper limit of 45 mCrab in 200 ks. Conclusions. The spectral energy distribution is modelled with a homogeneous one-zone synchrotron self Compton (SSC) emission plus contributions by external photons: the SSC emission contributes primarily to the X-ray band, whereas the contribution of the IC from the external disc and the broad line region match the hard gamma-ray spectrum observed.
ABSTRACT AGILE is detecting enhanced gamma-ray emission from a source positionally consistent wit... more ABSTRACT AGILE is detecting enhanced gamma-ray emission from a source positionally consistent with the microquasar Cygnus X-3. Integrating during the period 2011-05-28 07:58:37 UT to 2011-05-29 06:02:51 UT (MJD=55709.33-55710.25) the AGILE-GRID detected gamma-ray emission above 100 MeV from a source at Galactic coordinates (l, b) = (79.8, 0.3) ± 0.8 (stat.) ± 0.1 (syst.) deg, and flux F > 300 x 10-8 photons/cm2/s above 100 MeV (1-day multi-source-analysis significance in spinning mode ~4 sigma).
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Papers by Martina Cardillo