Some possible sources of IceCube TeV-PeV neutrino events

The IceCube Collaboration has observed 37 neutrino events in the energy range $30\, TeV\leq E_{\nu} \leq 2$ PeV and the sources of these neutrinos are unknown. Here we have shown that positions of 12 high energy blazars and the position of the FR-I galaxy Centaurus A, coincide within the error circles of ten IceCube events, the later being in the error circle of the highest energy event so far observed by IceCube. Two of the above blazars are simultaneously within the error circles of the Telescope Array hotspot and one IceCube event. We found that the blazar H2356-309 is within the error circles of three IceCube events. We propose that photohadronic interaction of the Fermi accelerated high energy protons with the synchrotron/SSC background photons in the nuclear region of these high energy blazars and AGN are probably responsible for some of the observed IceCube events.Comment: 14 pages, 3 figure, references adde

Multi-TeV flaring from blazars: Markarian 421 a case study

The TeV blazar Markarian 421 underwent multi-TeV flaring during April 2004 and simultaneously observed in x-ray and TeV energies. It was observed that the TeV outbursts had no counterparts in the lower energies, which implies that this might be an orphan flare. In the context of hadronic model, we have shown that this multi-TeV flaring can be produced due to the interaction of Fermi-accelerated protons of energy $\lesssim 168$ TeV with the background photons in the low energy tail of the synchrotron self-Compton spectrum of the blazar jet. We fit very well the flaring spectrum with this model. Based on this study, we speculate that Mrk 501 and PG 1553+113 are possible candidates for orphan flaring in the future.Comment: 8 pages, two columns, 3 figure

Photohadronic scenario in interpreting the February-March 2014 flare of 1ES 1011+496

The extraordinary multi-TeV flare from 1ES 1011 +496 during February-March 2014 was observed by MAGIC telescopes for 17 nights and the average spectrum of the whole period has a non-trivial shape. We have used the photohadronic model and a template EBL model to explain the average spectrum which fits well to the flare data. The spectral index $\alpha$ is the only free parameter in our model. We have also shown that the non-trivial nature of the spectrum is due to the change in the behavior of the optical depth above $\sim 600$ GeV $\gamma$-ray energy accompanied with the high SSC flux.Comment: 11 pages, 3 figures, LaTe

Blazar origin of some IceCube events

Recently ANTARES collaboration presented a time dependent analysis to a selected number of flaring blazars to look for upward going muon events produced from the charge current interaction of the muon neutrinos. We use the same list of flaring blazars to look for possible positional correlation with the IceCube neutrino events. In the context of photohadronic model we propose that the neutrinos are produced within the nuclear region of the blazar where Fermi accelerated high energy protons interact with the background synchrotron/SSC photons. Although we found that some objects from the ANTARES list are within the error circles of few IceCube events, the statistical analysis shows that none of these sources have a significant correlation.Comment: Latex file, 6 pages, two columns, 1 Figur

Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus A

The association of at least a dozen ultrahigh-energy cosmic-ray (UHECR) events with energy $\gtrsim 55$ EeV detected by the Pierre Auger Observatory (PAO) from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of UHECR acceleration in the jets of radio galaxies. In this work, we model radio to very high energy (VHE,$\gtrsim 100$ \rm GeV) $\gamma$-ray emission from Cen A, including GeV hardness detected by Fermi-LAT and TeV emission detected by HESS. We consider two scenarios: (i) Two zone synchrotron self-Compton (SSC) and external-Compton (EC) models, (ii) Two zone SSC, EC and photo-hadronic emission from cosmic ray interactions. The GeV hardness observed by Fermi-LAT can be explained using these two scenarios, where zone 2 EC emission is very important. Hadronic emission in scenario (ii) can explain VHE data with the same spectral slope as obtained through fitting UHECRs from Cen A. The peak luminosity in cosmic ray proton at 1 TeV, to explain the VHE $\gamma$-ray data is $\approx 2.5 \times 10^{46}$ erg/s. The bolometric luminosity in cosmic ray protons is consistent with the luminosity required to explain the origin of 13 UHECR signal events that are correlated with Cen A.Comment: 6 pages, 3 figures, Accepted for publication in MNRASL, Comments welcom

Revisiting constraints on 3+1 active-sterile neutrino mixing using IceCube data

Recent IceCube search results for sterile neutrino increased tension between the combined appearance and disappearance experiments. On the other hand, MiniBooNE latest data confirms at $4.9\sigma$ CL the short-baseline oscillation anomaly. We analyze published IceCube data based on two different active-sterile mixing schemes using one additional sterile neutrino flavor. We present exclusion regions in the parameter ranges $0.01 \le \sin^2 \theta_{24} \le 0.1$ and $0.1~{\rm eV}^2 \le \Delta m^2_{42} \le 10~{\rm eV}^2$ for the mass-mixing and flavor-mixing schemes. Under the more conservative mass-mixing scheme, $3\sigma$ CL allowed regions for the appearance experiment and MiniBooNE latest result are excluded at $\gtrsim 3\sigma$ CL. In case of less-restrictive flavor-mixing scheme, results from the appearance experiments are excluded at $\gtrsim 2\sigma$ CL. We also find that including prompt component of the atmospheric neutrino flux relaxes constraints on sterile mixing for $\Delta m^2_{42} \gtrsim 1~{\rm eV}^2$.Comment: 15 pages and 5 figures. Accepted for publication in JHE

Restore as translation: assistance in the Church of São João Batista in Belém (1994- 1996)

A intervenção realizada na Igreja de São João Batista, em Belém, pela Superintendência do IPHAN no Pará, entre 1994 e 1996, trouxe à tona dois aspectos significativos domonumento como bem cultural: o valor estético-histórico e o valor afetivo. Contando com o auxílio de documentos institucionais, notícias na imprensa e entrevistas, busca-sediscutir os sentidos da restauração como tarefa de tradução, face ao valor de contemporaneidade do monumento.The intervention held at the Church of São João Batista, in Belém, by IPHAN s office in Pará between 1994 and 1996 brought to light two significant aspects of the monument ascultural asset: the historic-aesthetic value and the affective value. With the aid of institutional documents, news in the press and interviews, seeks to discuss the directions of restoration as the translation task, given the contemporary value of the monument

«L’artista va a l’escola»: una experiència d’educació artística a Tarragona

El projecte «L’artista va a l’escola» neix el 2015 sota el paraigua del centre d’art El Teler de Llum amb la intenció de vincular l’art contemporani local amb els centres educatius de primària i secundària del municipi de Tarragona. Les coordinadores del projecte posen en contacte artistes del territori amb els col·legis i instituts per tal de dissenyar conjuntament processos educatius transversals des de la pintura, l’escultura, l’audiovisual, el teatre i la música.The project ‘L’artista va a l’escola’ began in 2015 under the auspicies of the art center El Teller de Llum with the intention of connecting local contemporary art with primary and secondary schools of the municipality of Tarragona. The project coordinators put local artists in touch with colleges and institutes in order to jointly design transversal educational processes including painting, sculpture, audiovisual, theater and music

Apagamentos na memória da Misericórdia no Pará : um estudo iconográfico

Arquitetura assistencial luso-brasileira da idade moderna à contemporaneidade : espaços, funções e protagonistas / coordenação [de] Joana Balsa de Pinho... [et al.]. - Lisboa : Theya, 2020. - ISBN 978-989-8916-98-3. - P. 85-96.Cabe discutir o fluxo da memória e do esquecimento na história das edificações de tratamento à saúde prestado pela Misericórdia em Belém, Pará. Sinalizar no mapa do presente o achado, como quer Benjamin, requer zelo com os vestígios que se inserem, no caso do antigo Hospital da Caridade, num «lugar de memória» que não o inclui na sua narrativa mítica. A respeito do Asilo de Alienados, o apagamento da «mancha negra» do confinamento dos doentes mentais deu lugar a uma escola de magistério, passando a Campus de Ciências da Saúde da Universidade do Estado do Pará. O local permanece ligado à ciência médica, porém não há qualquer vestígio das presenças anteriores. O apagamento dos vestígios materiais desses nosocômios impede a reconstrução das várias camadas existentes no sítio onde se escava, figurando em imagens saudosistas.We discuss the flow of memory and forgetting in the history of healthcare buildings provided by the Mercy in Belém, Pará. The signaling of the finding requires that we care for remains that, in the case of the former Charity Hospital, belong to a «memory place» which, however, does not include it in its mythic narrative. Regarding the Asylum of the Alienated, the deletion of the confinement of the mentally ill gave rise to a School of Teaching and then to the Health Sciences Campus of the University of the State of Pará. The site remains connected to medical science, but there is no trace of the previous presences. The deletion of the material traces of these hospitals prevents the reconstruction of several existing layers on the site of the dig, which figure in nostalgic images