Neutrinos from active black holes, sources of ultra high energy cosmic rays

A correlation between the highest energy Cosmic Rays (above ~ EeV) and the distribution of active galactic nuclei (AGN) gives rise to a prediction of neutrino production in the same sources. In this paper, we present a detailed AGN model, predicting neutrino production near the foot of the jet, where the photon fields from the disk and synchrotron radiation from the jet itself create high optical depths for proton-photon interactions. The protons escape from later shocks where the emission region is optically thin for proton-photon interactions. Consequently, Cosmic Rays are predicted to come from FR-I galaxies, independent of the orientation of the source. Neutrinos, on the other hand, are only observable from sources directing their jet towards Earth, i.e. flat spectrum radio sources and in particular BL Lac type objects, due to the strongly boosted neutrino emission.Comment: Accepted for publication in Astroparticle Physics; 30 pages, 8 figure

The diffuse neutrino flux from FR-II radio galaxies and blazars: A source property based estimate

Water and ice Cherenkov telescopes of the present and future aim for the detection of a neutrino signal from extraterrestrial sources at energies E>PeV. Some of the most promising extragalactic sources are Active Galactic Nuclei (AGN). In this paper, the neutrino flux from two kinds of AGN sources will be estimated assuming photohadronic interactions in the jet of the AGN. The first analyzed sample contains FR-II radio galaxies while the second AGN type examined are blazars. The result is highly dependent on the proton's index of the energy spectrum. To normalize the spectrum, the connection between neutrino and disk luminosity will be used by applying the jet-disk symbiosis model from Falcke and Biermann (1995). The maximum proton energy and thus, also the maximum neutrino energy of the source is connected to its disk luminosity, which was shown by Lovelace (1976) and was confirmed by Falcke et al. (1995).Comment: 24 pages, 14 figures, to be published in Astroparticle Physic

Magnetoelectric properties of A2A_2[FeCl5_5(H2_2O)] with A=A = K, Rb, Cs

The compounds $A_2$[FeCl$_5$(H$_2$O)] with $A=$ K, Rb, Cs are identified as new linear magnetoelectric materials. We present a detailed investigation of their linear magnetoelectric properties by measurements of pyroelectric currents, dielectric constants and magnetization. The anisotropy of the linear magnetoelectric effect of the K-based and Rb-based compound is consistent with the magnetic point group $m'm'm'$, already reported in literature. A symmetry analysis of the magnetoelectric effect of the Cs-based compound allows to determine the magnetic point group $mmm'$ and to develop a model for its magnetic structure. In addition, magnetic-field versus temperature phase diagrams are derived and compared to the closely related multiferroic (NH$_4$)$_2$[FeCl$_5$(H$_2$O)].Comment: 17 pages, 10 figures (updated to the weakly revised version that has been accepted for publication

The 2-10 keV emission properties of PSR B1937+21

We present the results of a BeppoSAX observation of the fastest pulsar known: PSR B1937+21. The ~ 200 ks observation (78.5 (34) ks MECS (LECS) exposure times) allowed us to investigate with high statistical significance both the spectral properties and the pulse profile shape. The absorbed power law spectral model gave a photon index of ~ 1.7 and N_H ~ 2.3 x 10^22 cm^-2. These values explain both a) the ROSAT non-detection and b) the deviant estimate of a photon index of ~ 0.8 obtained by ASCA. The pulse profile appears, for the first time, clearly double peaked with the main component much stronger than the other. The statistical significance is 10 sigma (main peak) and 5 sigma (secondary peak). The 1.6-10 keV pulsed fraction is consistent with 100%; only in the 1.6-4 keV band there is a ~ 2 sigma indication for a DC component. The secondary peak is detected significantly only for energies above 3 / 4 keV. The unabsorbed (2-10 keV) flux is F_2-10 = 3.7 x 10^-13 erg cm^-2 s^-1, implying a luminosity of L_X = 4.6 x 10^31 Theta (d/3.6 kpc)^2 erg s^-1 and an X-ray efficiency of eta = 4 x 10^-5 Theta, where Theta is the solid angle spanned by the emission beam. These results are in agreement with those obtained by ASCA.Comment: 4 pages, 4 figures, 2 tables. To appear in the Proceedings of the 270. WE-Heraeus Seminar on Neutron Stars, Pulsars and Supernova Remnants, Jan. 21-25, 2002, Physikzentrum Bad Honnef, eds W. Becker, H. Lesch & J. Truemper. Proceedings are available as MPE-Report 27

Moving I`iwi (Vestiaria coccinea) as a Surrogate for Future Translocations of Endangered `Akohekohe (Palmeria dolei)

Translocations often play an important role in the recovery of endangered species. To assess feasibility for translocation of endangered `Akohekohe (Palmeria dolei), we conducted an experimental translocation of I`iwi (Vestiaria coccinea) from east to west Maui. Mist-netting, veterinary screening of candidate birds, and helicopter transport of healthy I`iwi were successful, resulting in no injuries or mortalities. Translocated birds were assigned to two types of release. Hard release birds were radio tagged and released on the day of translocation. In contrast, soft release birds were held in large cages for 7 days and fed artificial nectar. During holding soft release I`iwi feeding rates, fecal production, and mass were monitored. Soft release birds suffered 33% mortality during the holding period. At the end of the holding period, soft release survivors were outfitted with a radio transmitter and released. All translocated I`iwi were followed by radio telemetry for an average of 21 days. Once released, soft release birds showed higher rates of movement, possibly reflecting conflict with established hard released I`iwi. Our results suggest that translocation efforts for wild `Akohekohe will be successful if hard release protocols are followed

Lessons learned: rearing the crown-boring weevil, Ceutorhynchus scrobicollis (Coleoptera: Curculionidae), in containment for biological control of garlic mustard (Alliaria petiolata)

In this paper, we describe lessons learned and protocols developed after a decade of rearing Ceutorhynchus scrobicollis Nerenscheimer and Wagner in a Biosafety Level 2 containment facility. We have developed these protocols in anticipation of approval to release C. scrobicollis in North America for the biocontrol of garlic mustard. The rearing protocol tried to minimize the potential of attack by the adult parasitoid, Perilitus conseutor, which may be present in field collected C. scrobicollis from Europe to prevent inadvertent introduction of parasitoids into North America. All C. scrobicollis used for our quarantine rearing were field collected near Berlin, Germany. We have successfully reared C. scrobicollis on caged garlic mustard plants in a growth chamber by alternating temperatures and photoperiods to simulate those in its native range. In Germany, C. scrobicollis produces one generation per year and F1 adults emerge in late May. In containment, a new generation of adults emerged an average of 108 days after adults were placed on plants. We found the optimal time spent to collect F1 adults was four weeks after the appearance of the first F1 adult, with 95% of potential adults collected. Simulating a three-month summer aestivation period, followed by a week of fall, and three weeks of winter conditions resulted in optimum levels of oviposition in F1 females. Larvae first hatched 8- to-10 days after adults were placed on plants at 15/14 C day/night temperatures with a 9.5 hour photoperiod. We therefore recommend that C. scrobicollis adults are removed from garlic mustard rosettes after 8 days. This will maximize the period of female oviposition while minimizing the time when larvae are available for attack from P. conseutor

Theoretical analysis of STM-derived lifetimes of excitations in the Shockley surface state band of Ag(111)

We present a quantitative many-body analysis using the GW approximation of the decay rate $\Gamma$ due to electron-electron scattering of excitations in the Shockley surface state band of Ag(111), as measured using the scanning tunnelling microscope (STM). The calculations include the perturbing influence of the STM, which causes a Stark-shift of the surface state energy $E$ and concomitant increase in $\Gamma$. We find $\Gamma$ varies more rapidly with $E$ than recently found for image potential states, where the STM has been shown to significantly affect measured lifetimes. For the Shockley states, the Stark-shifts that occur under normal tunnelling conditions are relatively small and previous STM-derived lifetimes need not be corrected.Comment: 4 pages, 3 figure

Understanding residents’ capacities to support evacuated populations : A study of earthquake and tsunami evacuation for Napier Hill, Napier, Aotearoa New Zealand.

Due to a large regional subduction zone (the Hikurangi subduction zone) and localised faults, Napier City located on the East Coast of Aotearoa/New Zealand is vulnerable to earthquake and tsunami events. On feeling a long or strong earthquake people will need to evacuate immediately inland or to higher ground to avoid being impacted by a tsunami, of which the first waves could start to arrive within 20 minutes (based on the Hikurangi earthquake and tsunami scenario presented in Power et al., 2018). Napier Hill is one such area of higher land, and it is estimated that up to 12,000 people could evacuate there in the 20 minutes following a long or strong earthquake. To understand the capacity of Napier Hill residents to support evacuees, three focus groups were held with a diverse sample of residents from Napier Hill on 21 and 22 July 2019. A follow up email was sent to all participants a week after the focus groups, containing a link to a short six question survey, which was completed by 68 people, most of whom were additional to the focus group attendees. Data from the focus groups and the survey was analysed qualitatively using thematic analysis. The findings highlight that in general people were happy to host evacuees and offer support if they were in a position to do so. However, key issues in being able to offer support included the likely lack of resources available after a disaster, ranging from basic needs though to agency support. The research findings will directly inform Napier City Council and Hawke’s Bay Civil Defence Emergency Management Group’s planning for future readiness and response by providing valuable insights for evacuation planningfalseWellingtonHawke's Bay Civil Defence Emergency Management Grou