Search

Your search keyword '"Caragiulo, M"' showing total 5 results
Start Over Author "Caragiulo, M" Database MEDLINE
5 results on '"Caragiulo, M"'

1. Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data.

Author

Abdollahi S, Ackermann M, Ajello M, Albert A, Atwood WB, Baldini L, Barbiellini G, Bellazzini R, Bissaldi E, Bloom ED, Bonino R, Bottacini E, Brandt TJ, Bruel P, Buson S, Caragiulo M, Cavazzuti E, Chekhtman A, Ciprini S, Costanza F, Cuoco A, Cutini S, D'Ammando F, de Palma F, Desiante R, Digel SW, Di Lalla N, Di Mauro M, Di Venere L, Donaggio B, Drell PS, Favuzzi C, Focke WB, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Green D, Guiriec S, Harding AK, Jogler T, Jóhannesson G, Kamae T, Kuss M, Larsson S, Latronico L, Li J, Longo F, Loparco F, Lubrano P, Magill JD, Malyshev D, Manfreda A, Mazziotta MN, Meehan M, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monzani ME, Morselli A, Negro M, Nuss E, Ohsugi T, Omodei N, Paneque D, Perkins JS, Pesce-Rollins M, Piron F, Pivato G, Principe G, Rainò S, Rando R, Razzano M, Reimer A, Reimer O, Sgrò C, Simone D, Siskind EJ, Spada F, Spandre G, Spinelli P, Strong AW, Tajima H, Thayer JB, Torres DF, Troja E, Vandenbroucke J, Zaharijas G, and Zimmer S

Abstract

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10^{-3}. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Published
2017
Full Text
View/download PDF

2. Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope.

Author

Ajello M, Albert A, Anderson B, Baldini L, Barbiellini G, Bastieri D, Bellazzini R, Bissaldi E, Blandford RD, Bloom ED, Bonino R, Bottacini E, Bregeon J, Bruel P, Buehler R, Caliandro GA, Cameron RA, Caragiulo M, Caraveo PA, Cecchi C, Chekhtman A, Ciprini S, Cohen-Tanugi J, Conrad J, Costanza F, D'Ammando F, de Angelis A, de Palma F, Desiante R, Di Mauro M, Di Venere L, Domínguez A, Drell PS, Favuzzi C, Focke WB, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Glanzman T, Godfrey G, Guiriec S, Horan D, Jóhannesson G, Katsuragawa M, Kensei S, Kuss M, Larsson S, Latronico L, Li J, Li L, Longo F, Loparco F, Lubrano P, Madejski GM, Maldera S, Manfreda A, Mayer M, Mazziotta MN, Meyer M, Michelson PF, Mirabal N, Mizuno T, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Negro M, Nuss E, Okada C, Orlando E, Ormes JF, Paneque D, Perkins JS, Pesce-Rollins M, Piron F, Pivato G, Porter TA, Rainò S, Rando R, Razzano M, Reimer A, Sánchez-Conde M, Sgrò C, Simone D, Siskind EJ, Spada F, Spandre G, Spinelli P, Takahashi H, Thayer JB, Torres DF, Tosti G, Troja E, Uchiyama Y, Wood KS, Wood M, Zaharijas G, and Zimmer S

Abstract

We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the γ-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5×10^{-12}  GeV^{-1} for ALP masses 0.5≲m_{a}≲5  neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the γ-ray opacity of the Universe.

Published
2016
Full Text
View/download PDF

3. Measurement of the high-energy gamma-ray emission from the Moon with the Fermi Large Area Telescope.

Author

Ackermann M, Ajello M, Albert A, Atwood WB, Baldini L, Barbiellini G, Bastieri D, Bellazzini R, Bissaldi E, Blandford RD, Bonino R, Bottacini E, Bregeon J, Bruel P, Buehler R, Caliandro GA, Cameron RA, Caragiulo M, Caraveo PA, Cavazzuti E, Cecchi C, Chekhtman A, Chiang J, Chiaro G, Ciprini S, Claus R, Cohen-Tanugi J, Costanza F, Cuoco A, Cutini S, D'Ammando F, de Angelis A, de Palma F, Desiante R, Digel SW, Di Venere L, Drell PS, Favuzzi C, Fegan SJ, Focke WB, Franckowiak A, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Glanzman T, Godfrey G, Grenier IA, Grove JE, Guiriec S, Harding AK, Hewitt JW, Horan D, Hou X, Iafrate G, Jóhannesson G, Kamae T, Kuss M, Larsson S, Latronico L, Li J, Li L, Longo F, Loparco F, Lovellette MN, Lubrano P, Magill J, Maldera S, Manfreda A, Mayer M, Mazziotta MN, Michelson PF, Mitthumsiri W, Mizuno T, Monzani ME, Morselli A, Murgia S, Nuss E, Omodei N, Orlando E, Ormes JF, Paneque D, Perkins JS, Pesce-Rollins M, Petrosian V, Piron F, Pivato G, Rainò S, Rando R, Razzano M, Reimer A, Reimer O, Reposeur T, Sgrò C, Siskind EJ, Spada F, Spandre G, Spinelli P, Takahashi H, Thayer JB, Thompson DJ, Tibaldo L, Torres DF, Tosti G, Troja E, Vianello G, Winer BL, Wood KS, Yassine M, Cerutti F, Ferrari A, and Sala PR

Abstract

We have measured the gamma-ray emission spectrum of the Moon using the data collected by the Large Area Telescope onboard the Fermi satellite during its first seven years of operation, in the energy range from 30 MeV up to a few GeV. We have also studied the time evolution of the flux, finding a correlation with the solar activity. We have developed a full Monte Carlo simulation describing the interactions of cosmic rays with the lunar surface. The results of the present analysis can be explained in the framework of this model, where the production of gamma rays is due to the interactions of cosmic-ray proton and helium nuclei with the surface of the Moon. Finally, we have used our simulation to derive the cosmic-ray proton and helium spectra near Earth from the Moon gamma-ray data.

Published
2016
Full Text
View/download PDF

4. Resolving the Extragalactic γ-Ray Background above 50 GeV with the Fermi Large Area Telescope.

Author

Ackermann M, Ajello M, Albert A, Atwood WB, Baldini L, Ballet J, Barbiellini G, Bastieri D, Bechtol K, Bellazzini R, Bissaldi E, Blandford RD, Bloom ED, Bonino R, Bregeon J, Britto RJ, Bruel P, Buehler R, Caliandro GA, Cameron RA, Caragiulo M, Caraveo PA, Cavazzuti E, Cecchi C, Charles E, Chekhtman A, Chiang J, Chiaro G, Ciprini S, Cohen-Tanugi J, Cominsky LR, Costanza F, Cutini S, D'Ammando F, de Angelis A, de Palma F, Desiante R, Digel SW, Di Mauro M, Di Venere L, Domínguez A, Drell PS, Favuzzi C, Fegan SJ, Ferrara EC, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giommi P, Giordano F, Giroletti M, Godfrey G, Green D, Grenier IA, Guiriec S, Hays E, Horan D, Iafrate G, Jogler T, Jóhannesson G, Kuss M, La Mura G, Larsson S, Latronico L, Li J, Li L, Longo F, Loparco F, Lott B, Lovellette MN, Lubrano P, Madejski GM, Magill J, Maldera S, Manfreda A, Mayer M, Mazziotta MN, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Negro M, Nuss E, Ohsugi T, Okada C, Omodei N, Orlando E, Ormes JF, Paneque D, Perkins JS, Pesce-Rollins M, Petrosian V, Piron F, Pivato G, Porter TA, Rainò S, Rando R, Razzano M, Razzaque S, Reimer A, Reimer O, Reposeur T, Romani RW, Sánchez-Conde M, Schmid J, Schulz A, Sgrò C, Simone D, Siskind EJ, Spada F, Spandre G, Spinelli P, Suson DJ, Takahashi H, Thayer JB, Tibaldo L, Torres DF, Troja E, Vianello G, Yassine M, and Zimmer S

Abstract

The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for the first time, the source count distribution, dN/dS, of extragalactic γ-ray sources at E>50  GeV and find that it is compatible with a Euclidean distribution down to the lowest measured source flux in the 2FHL (∼8×10^{-12}  ph cm^{-2} s^{-1}). We employ a one-point photon fluctuation analysis to constrain the behavior of dN/dS below the source detection threshold. Overall, the source count distribution is constrained over three decades in flux and found compatible with a broken power law with a break flux, S_{b}, in the range [8×10^{-12},1.5×10^{-11}]  ph cm^{-2} s^{-1} and power-law indices below and above the break of α_{2}∈[1.60,1.75] and α_{1}=2.49±0.12, respectively. Integration of dN/dS shows that point sources account for at least 86_{-14}^{+16}% of the total extragalactic γ-ray background. The simple form of the derived source count distribution is consistent with a single population (i.e., blazars) dominating the source counts to the minimum flux explored by this analysis. We estimate the density of sources detectable in blind surveys that will be performed in the coming years by the Cherenkov Telescope Array.

Published
2016
Full Text
View/download PDF

5. Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data.

Author

Ackermann M, Albert A, Anderson B, Atwood WB, Baldini L, Barbiellini G, Bastieri D, Bechtol K, Bellazzini R, Bissaldi E, Blandford RD, Bloom ED, Bonino R, Bottacini E, Brandt TJ, Bregeon J, Bruel P, Buehler R, Caliandro GA, Cameron RA, Caputo R, Caragiulo M, Caraveo PA, Cecchi C, Charles E, Chekhtman A, Chiang J, Chiaro G, Ciprini S, Claus R, Cohen-Tanugi J, Conrad J, Cuoco A, Cutini S, D'Ammando F, de Angelis A, de Palma F, Desiante R, Digel SW, Di Venere L, Drell PS, Drlica-Wagner A, Essig R, Favuzzi C, Fegan SJ, Ferrara EC, Focke WB, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Glanzman T, Godfrey G, Gomez-Vargas GA, Grenier IA, Guiriec S, Gustafsson M, Hays E, Hewitt JW, Horan D, Jogler T, Jóhannesson G, Kuss M, Larsson S, Latronico L, Li J, Li L, Llena Garde M, Longo F, Loparco F, Lubrano P, Malyshev D, Mayer M, Mazziotta MN, McEnery JE, Meyer M, Michelson PF, Mizuno T, Moiseev AA, Monzani ME, Morselli A, Murgia S, Nuss E, Ohsugi T, Orienti M, Orlando E, Ormes JF, Paneque D, Perkins JS, Pesce-Rollins M, Piron F, Pivato G, Porter TA, Rainò S, Rando R, Razzano M, Reimer A, Reimer O, Ritz S, Sánchez-Conde M, Schulz A, Sehgal N, Sgrò C, Siskind EJ, Spada F, Spandre G, Spinelli P, Strigari L, Tajima H, Takahashi H, Thayer JB, Tibaldo L, Torres DF, Troja E, Vianello G, Werner M, Winer BL, Wood KS, Wood M, Zaharijas G, and Zimmer S

Abstract

The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass ≲100  GeV annihilating via quark and τ-lepton channels.

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results