Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bolonia study programme

Options:
  Reset


11 - 20 / 32
First pagePrevious page1234Next pageLast page
11.
Sensitivity projections for dark matter searches with the Fermi large area telescope
Gabrijela Zaharijas, Collaboration Fermi LAT, 2016, original scientific article

Abstract: The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Among indirect searchtechniques, which look for stable products from the annihilation or decay of dark matter particles, or from axions coupling to high-energy photons, observations of the γ -ray sky have come to prominence over the last few years, because of the excellent sensitivity of the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range from 20 meV to above 300 GeV is particularly well suited for searching for products of the interactions of dark matter particles. In this report we describe methods used to search for evidence of dark matter with the LAT, and review the status of searches performed with up to six years of LAT data. We also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. We project the expected sensitivities of each search method for 10 and 15 years of LAT data taking. In particular, we find that the sensitivity of searches targeting dwarf galaxies, which provide the best limits currently, will improve faster than the square root of observing time. Current LAT limits for dwarf galaxies using six years of data reach the thermal relic level for masses up to 120 GeV for the bb ̄ annihilation channel for reasonable dark matter density profiles. With projected discoveries of additional dwarfs, these limits could extend to about 250 GeV. With as much as 15 years of LAT data these searches would be sensitive to dark matter annihilations at the thermal relic cross section for masses to greater than 400 GeV (200 GeV) in the bb ̄(τ+τ−) annihilation channels.
Found in: ključnih besedah
Summary of found: ...Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope mission. The LAT energy range...
Keywords: dark matter, gamma rays
Published: 20.06.2016; Views: 2382; Downloads: 0
.pdf Fulltext (4,66 MB)

12.
FERMI-LAT OBSERVATIONS OF THE LIGO EVENT GW150914
Gabrijela Zaharijas, Collaboration Fermi LAT, Collaboration LIGO, 2016, original scientific article

Abstract: The Fermi Large Area Telescope (LAT) has an instantaneous field of view (FoV) covering ~1 5 of the sky and it completes a survey of the entire sky in high-energy gamma-rays every 3 hr. It enables searches for transient phenomena over timescales from milliseconds to years. Among these phenomena could be electromagnetic counterparts to gravitational wave (GW) sources. In this paper, we present a detailed study of the LAT observations relevant to Laser Interferometer Gravitational-wave Observatory (LIGO) event GW150914, which is the first direct detection of gravitational waves and has been interpreted as being due to the coalescence of two stellar-mass black holes. The localization region for GW150914 was outside the LAT FoV at the time of the GW signal. However, as part of routine survey observations, the LAT observed the entire LIGO localization region within ∼70 minutes of the trigger and thus enabled a comprehensive search for a γ-ray counterpart to GW150914. The study of the LAT data presented here did not find any potential counterparts to GW150914, but it did provide limits on the presence of a transient counterpart above 100 MeV on timescales of hours to days over the entire GW150914 localization region.
Found in: ključnih besedah
Summary of found: ...survey of the entire sky in high-energy gamma-rays every 3 hr. It enables searches for...
Keywords: gravitational waves, gamma rays
Published: 20.06.2016; Views: 2439; Downloads: 0
.pdf Fulltext (2,04 MB)

13.
Observations of M31 and M33 with the Fermi Large Area Telescope: A Galactic Center Excess in Andromeda?
Gabrijela Zaharijas, 2017, original scientific article

Found in: ključnih besedah
Summary of found: ... gamma-rays, Fermi LAT, Andromeda galaxy...
Keywords: gamma-rays, Fermi LAT, Andromeda galaxy
Published: 07.03.2017; Views: 2218; Downloads: 1
.pdf Fulltext (1,35 MB)

14.
Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1713.7−3946
Marko Zavrtanik, Danilo Zavrtanik, Lili Yang, Serguei Vorobiov, Samo Stanič, Gašper Kukec Mezek, F. Acero, 2017, original scientific article

Found in: ključnih besedah
Summary of found: ...very-high energy gamma-rays, supernova remnants (SNR), SNR RX J1713.7−3946, Cherenkov Telescope Array...
Keywords: very-high energy gamma-rays, supernova remnants (SNR), SNR RX J1713.7−3946, Cherenkov Telescope Array
Published: 10.05.2017; Views: 2264; Downloads: 0
.pdf Fulltext (997,39 KB)

15.
The Fermi Galactic Center GeV Excess and Implications for Dark Matter
Gabrijela Zaharijas, 2017, original scientific article

Found in: ključnih besedah
Summary of found: ...– Galaxy: center – Galaxy: halo – gamma rays: general – ISM: general...
Keywords: cosmic rays – Galaxy: bulge – Galaxy: center – Galaxy: halo – gamma rays: general – ISM: general
Published: 13.07.2017; Views: 1927; Downloads: 0
.pdf Fulltext (7,21 MB)

16.
Ricerca di segnali di decadimento di materia oscura nell'emissione gamma isotropa rilevata dall'esperimento Fermi-LAT
Valentina Buran, master's thesis

Found in: ključnih besedah
Keywords: gamma rays
Published: 28.08.2017; Views: 1744; Downloads: 0
.pdf Fulltext (11,36 MB)

17.
Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus A
Jagdish Joshi, Marlui Miranda, Lili Yang, Soebur Razzaque, 2017, published scientific conference contribution abstract

Abstract: The association of at least a dozen ultrahigh-energy cosmic-ray (UHECR) events with energy 54 EeV or higher detected by the Pierre Auger Observatory from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of UHECR acceleration in the jets of radio galaxies. Multiwavelength observations of Centaurus-A suggest that the inner jet is likely the site for particle acceleration, which emits in X-ray to very high-energy (VHE) gamma-ray. We model broadband spectral energy distribution with emission from shock-accelerated electrons and protons in a combined synchrotron-self-Compton and photo-hadronic scenario. The UHECR flux from Centaurus-A, required to explain Pierre Auger data, successfully explains observed VHE gamma rays as photo-hadronic emission.
Found in: ključnih besedah
Summary of found: ...Auger data, successfully explains observed VHE gamma rays as photo-hadronic emission....
Keywords: Centaurus A, gamma ray, cosmic rays
Published: 17.01.2018; Views: 1381; Downloads: 0
.pdf Fulltext (2,27 MB)

18.
M31 gamma-ray emission - a closer look at different explanations
Jovana Petrovic, Pasquale D. Serpico, Christopher Eckner, Tijana Prodanovic, 2017, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...Milky Way, M31, gamma- rays, millisecond pulsars, dark matter...
Keywords: Milky Way, M31, gamma-rays, millisecond pulsars, dark matter
Published: 30.01.2018; Views: 1566; Downloads: 94
.pdf Fulltext (773,73 KB)

19.
Cherenkov Telescope Array: The Next Generation Gamma-ray Observatory
Danilo Zavrtanik, Marko Zavrtanik, Gabrijela Zaharijas, Lili Yang, Serguei Vorobiov, Samo Stanič, Gašper Kukec Mezek, Christopher Eckner, Rene A. Ong, 2017, published scientific conference contribution

Abstract: The Cherenkov Telescope Array (CTA) will be the next-generation gamma-ray observatory, investigating gamma-ray and cosmic ray astrophysics at energies from 20 GeV to more than 300 TeV. The observatory, consisting of large arrays of imaging atmospheric Cherenkov telescopes in both the southern and northern hemispheres, will provide full-sky coverage and will achieve a sensitivity improved by up to an order of magnitude compared to existing instruments such as H.E.S.S., MAGIC and VERITAS. CTA is expected to discover hundreds of new TeV gammaray sources, allowing it to significantly advance our understanding of the origin of cosmic rays, to probe much larger distances in the universe, and to search for WIMP dark matter with unprecedented sensitivity in TeV mass range. The development of CTA is being carried out by a worldwide consortium of scientists from 32 countries. Consortium scientists have developed the core scientific programme of CTA and institutes of the Consortium are expected to provide the bulk of the CTA components. The construction of CTA is overseen by the CTA Observatory that will in the future manage observatory operations, the guest observer programme, and data dissemination. This talk will review the scientific motivation for CTA, focusing on the key science projects that form the core programme of research. The talk will outline the design of CTA, including the science drivers, overall concept, performance optimization, and array layouts. The current status of CTA, including sites, prototype telescope progress, and steps forward will also be described.
Found in: ključnih besedah
Summary of found: ...300 TeV. The observatory, consisting of large ar rays of imaging atmospheric Cherenkov telescopes in both...
Keywords: CTA, next-generation gamma-ray observatory, gamma rays
Published: 16.02.2018; Views: 1463; Downloads: 89
.pdf Fulltext (1,35 MB)

20.
The Dark Matter Programme of the Cherenkov Telescope Array
A. Morselli, Christopher Eckner, Gašper Kukec Mezek, Samo Stanič, Serguei Vorobiov, Lili Yang, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, 2017, published scientific conference contribution

Found in: ključnih besedah
Summary of found: ...dark matter, CTA, gamma rays...
Keywords: dark matter, CTA, gamma rays
Published: 16.02.2018; Views: 1254; Downloads: 79
.pdf Fulltext (769,34 KB)

Search done in 0 sec.
Back to top