Aims. We calculate the contribution to the neutrino background from the non-jetted active galactic nuclei (AGN) population following the recent IceCube association of TeV neutrinos with NGC 1068. ...Methods. We exploited our robust knowledge of the AGN X-ray luminosity function and evolution and converted it to the neutrino band by using NGC 1068 as a benchmark, together with a theoretically motivated neutrino spectrum. Results. The resulting neutrino background up to redshift 5 does not violate either the IceCube diffuse flux or the upper bounds for non-jetted AGN, although barely so. This is consistent with a scenario in which the latter class makes a substantial contribution mostly below 1 PeV, while jetted AGN, that is, blazars, dominate above this energy, in intriguing agreement with the dip in the neutrino data at ∼300 TeV. More and better IceCube data on Seyfert galaxies will allow us to constrain the fraction of neutrino emitters among non-jetted AGN.
Searches for new physics in the coherent elastic neutrino-nucleus scattering require a precise knowledge of the neutrino flux and energy spectrum. In this paper we investigate the feasibility and the ...performance of an experiment based on a Formula omittedCr source, whose neutrino spectrum is known and whose activity can be heat-monitored at few permil level. With a 5 MCi source placed at Formula omitted cm from the detector, under an exposure of two Formula omittedCr half-lives (55.4 days), we evaluate 3900 (900) counts on a 2000 cm Formula omitted target of germanium (sapphire) featuring an energy threshold of 8 (20) eV. To further increase the exposure, multiple activations of the same source could be possible.
BULLKID is an R&D project on a cryogenic particle detector to search for rare low-energy processes such as low-mass dark matter and neutrino coherent scattering off nuclei. The detector unit we are ...designing consists in an array of ~ 100 silicon absorbers sensed by phonon-mediated, microwave-multiplexed kinetic inductance detectors, with energy threshold below 100 eV and total target mass around 30 g. The single detector unit will be engineered to ensure a straightforward scalability to a future kg-scale experiment.
The CALDER project aims to realize cryogenic light detectors for the next generation of experiments searching for rare events. More in detail, the main application of these devices will be the ...background suppression in future cryogenic calorimetric experiments searching for neutrinoless double beta decay (
0
ν
DBD). This is the case of CUPID, a next-generation
0
ν
DBD observatory, able to take advantage from particle identification to dramatically reduce the background events. In this contribution, we show the status of the CALDER project. The light sensors developed in this R&D are based on kinetic inductance detector operated in the phonon-mediated approach. Their energy resolution (20 eV), time response (
μ
s) and multiplexing capability make them very promising for the future CUPID experiment.
Abstract Searches for new physics in the coherent elastic neutrino-nucleus scattering require a precise knowledge of the neutrino flux and energy spectrum. In this paper we investigate the ...feasibility and the performance of an experiment based on a $$^{51}$$ 51 Cr source, whose neutrino spectrum is known and whose activity can be heat-monitored at few permil level. With a 5 MCi source placed at $$\sim 25$$ ∼25 cm from the detector, under an exposure of two $$^{51}$$ 51 Cr half-lives (55.4 days), we evaluate 3900 (900) counts on a 2000 cm$$^3$$ 3 target of germanium (sapphire) featuring an energy threshold of 8 (20) eV. To further increase the exposure, multiple activations of the same source could be possible.
Searches for new physics in the coherent elastic neutrino-nucleus scattering require a precise knowledge of the neutrino flux and energy spectrum. In this paper we investigate the feasibility and the ...performance of an experiment based on a
51
Cr source, whose neutrino spectrum is known and whose activity can be heat-monitored at few permil level. With a 5 MCi source placed at
∼
25
cm from the detector, under an exposure of two
51
Cr half-lives (55.4 days), we evaluate 3900 (900) counts on a 2000 cm
3
target of germanium (sapphire) featuring an energy threshold of 8 (20) eV. To further increase the exposure, multiple activations of the same source could be possible.
Abstract
The idea of measuring the coherent elastic nuclear scattering of neutrinos emitted by a high intensity
51
Cr radioactive source is investigated. To produce the high intensity source, the ...radioactive material used in the GALLEX experiment (36 kg of Chromium 38.6% enriched in
50
Cr) could be reactivated to an intensity of few MCi. The advantages of this source are that the activity can be measured at few per mill level and that the neutrino spectrum is well known. With a target volume of 2 dm
3
of low-threshold detectors, if the background is limited, the crosssection might be measured with few percent precision. In this work the requirements for the experiment will be shown and the envisioned experimental challenges will also be discussed.
The idea of measuring the coherent elastic nuclear scattering of neutrinos emitted by a high intensity 51Cr radioactive source is investigated. To produce the high intensity source, the radioactive ...material used in the GALLEX experiment (36 kg of Chromium 38.6% enriched in 50Cr) could be reactivated to an intensity of few MCi. The advantages of this source are that the activity can be measured at few per mill level and that the neutrino spectrum is well known. With a target volume of 2 dm3 of low-threshold detectors, if the background is limited, the crosssection might be measured with few percent precision. In this work the requirements for the experiment will be shown and the envisioned experimental challenges will also be discussed.
Aims. We calculate the contribution to the neutrino background from the non-jetted active galactic nuclei (AGN) population following the recent IceCube association of TeV neutrinos with NGC 1068. ...Methods. We exploit our robust knowledge of the AGN X-ray luminosity function and evolution and convert it to the neutrino band by using NGC 1068 as a benchmark and a theoretically motivated neutrino spectrum. Results. The resulting neutrino background up to redshift 5 does not violate either the IceCube diffuse flux or the upper bounds for non-jetted AGN, although barely so. This is consistent with a scenario where the latter class makes a substantial contribution mostly below 1 PeV, while jetted AGN, i.e. blazars, dominate above this energy, in intriguing agreement with the dip in the neutrino data at ~ 300 TeV. More and better IceCube data on Seyfert galaxies will allow us to constrain the fraction of neutrino emitters among non-jetted AGN.
We present a comprehensive multi-messenger study of NGC 1068, the prototype
Seyfert II galaxy recently associated with high-energy IceCube neutrinos.
Various aspects of the source, including its ...nuclear activity, jet, outflow,
and starburst region, are analyzed in detail using a multi-wavelength approach
and relevant luminosities are derived. We then explore its gamma-ray and
neutrino emissions and investigate potential mechanisms underlying these
phenomena and their relations with the different astrophysical components to
try to understand which one is responsible for the IceCube neutrinos. By first
using simple order-of-magnitude arguments and then applying specific
theoretical models, we infer that only the region close to the accretion disc
around the supermassive black hole has both the right density of X-ray photons
needed to provide the targets for protons to sustain neutrino production and of
optical/infrared photons required to absorb the associated but unobserved gamma
rays. We conclude by highlighting ongoing efforts to constrain a possible broad
connection between neutrinos and active galactic nuclei, as well as future
synergies between astronomical and neutrino facilities.
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