Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic messengers that may escape much denser media than photons. They travel unaffected over cosmological distances, carrying information from the inner regions of the astrophysical engines from which they are emitted (and from which photons and charged cosmic rays cannot reach us). For the same reasons, such messengers could also reveal new, hidden sources that have not been observed by conventional photon-based astronomy. Coincident observation of GWs and HENs may thus play a critical role in multimessenger astronomy. This is particularly true at the present time owing to the advent of a new generation of dedicated detectors: the neutrino telescopes IceCube at the South Pole and ANTARES in the Mediterranean Sea, as well as the GW interferometers Virgo in Italy and LIGO in the United States. Starting from 2007, several periods of concomitant data taking involving these detectors have been conducted. More joint data sets are expected with the next generation of advanced detectors that are to be operational by 2015, with other detectors, such as KAGRA in Japan, joining in the future. Combining information from these independent detectors can provide origin always of constraining the physical processes driving the sources and also help confirm the astrophysical origin of a GW or HEN signal in case of coincident observation. Given the complexity of the instruments, a successful joint analysis of this combined GW and HEN observational data set will be possible only if the expertise and knowledge of the data is shared between the two communities. This Colloquium aims at providing an overview of both theoretical and experimental state of the art and perspectives for GW and HEN multimessenger astronomy

Observational Constraints on Multi-messenger Sources of Gravitational Waves and High-energy Neutrinos

It remains an open question to what extent many of the astronomical sources of intense bursts of electromagnetic radiation are also strong emitters of non-photon messengers, in particular gravitational waves (GWs) and high-energy neutrinos (HENs). Such emission would provide unique insights into the physics of the bursts; moreover some suspected classes, e.g. choked gamma-ray bursts, may in fact only be identifiable via these alternative channels. Here we explore the reach of current and planned experiments to address this question. We derive constraints on the rate of GW and HEN bursts per Milky Way equivalent (MWE) galaxy based on independent observations by the initial LIGO and Virgo GW detectors and the partially completed IceCube (40-string) HEN detector. We take into account the blue-luminosity-weighted distribution of nearby galaxies, assuming that source distribution follows the blue-luminosity distribution. We then estimate the reach of joint GW+HEN searches using advanced GW detectors and the completed cubic-km IceCube detector to probe the joint parameter space. We show that searches undertaken by advanced detectors will be capable of detecting, constraining or excluding, several existing models with one year of observation

Gamma-ray Burst Afterglow Plateaus and Gravitational Waves: Multi-messenger Signature of a Millisecond Magnetar?

The existence of a shallow decay phase in the early X-ray afterglows of gamma-ray bursts is a common feature. Here we investigate the possibility that this is connected to the formation of a highly magnetized millisecond pulsar, pumping energy into the fireball on timescales longer than the prompt emission. In this scenario, the nascent neutron star could undergo a secular bar-mode instability, leading to gravitational wave losses which would affect the neutron star spin-down. In this case, nearby gamma-ray bursts with isotropic energies of the order of 1050 ergs would produce a detectable gravitational wave signal emitted in association with an observed X-ray light-curve plateau, over relatively long timescales of minutes to about an hour. The peak amplitude of the gravitational wave signal would be delayed with respect to the gamma-ray burst trigger, offering gravitational wave interferometers such as the advanced LIGO and Virgo the challenging possibility of catching its signature on the fly

Detection of Cherry Leaf Roll Virus in intensively managed grafted English (Persian) walnut trees in Italy

Blackline disease, caused by Cherry leaf roll virus (CLRV), is considered a serious threat limiting English walnut (Juglans regia L.) production in Italy and the EU if walnut species other than J. regia are used as rootstock. In spring 2014, canopy decline or death of several walnut trees associated with presence of a necrotic strip at the rootstock-scion junction was observed on plants grafted onto \u2018Paradox' (J. hindsii 7 J. regia) in a commercial orchard located in the Veneto region (north-eastern Italy). To ascertain the presence of CLRV in this orchard and in other walnut intensively managed orchards located in the same region, a monitoring was carried out in 2014- 2015

LANDSLIDE RISK MANAGEMENT USING THE MATHEMATICAL MODEL TRIGRS: Gestão de riscos a deslizamentos de terra utilizando o modelo matemático TRIGRS

Landslides are recurrent events in Brazil, usually triggered by intense rainfall. When these events occur in urban areas, they end up becoming disasters due to economic damage, social impact, and loss of human life. The identification and monitoring of landslide-prone areas are crucial to avoid fatalities. Therefore, the aims of this work are a temporal analysis of the Factor of Safety variation in Campos do Jordão, using the mathematical model TRIGRS. During the analyzed period, two heavy rainfall events were recorded in the area and triggered landslides. The results show TRIGRS efficiency in correctly identify landslide-prone areas and its applicability to become a useful tool for urban planning and early warning systems