| Newsletter Portuguese May/July 2018 |
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ICRANet Boletim informativo
ICRANet Boletim informativo
Maio – Junho – Julho de 2018
SUMÁRIO
1. O trabalho de C.R. Argüelles, A. Krut, J.A. Rueda, R. Ruffini “Novel constraints on fermionic dark matter from galactic observables I: The Milky Way” acaba de ser aceites para publicação na revista Physics of the Dark Universe, 12 de julho de 2018 2. 15o Encontro Marcel Grossmann (MG15) – Roma, 1-7 de julho de 2018 3. Visita do Prof. Ruffini à Albânia, 23-24 de maio de 2018 4. Prof. Ruffini nomeado membro do Comitê consultivo Horizonte 2020 para o programa Marie Skłodowska-Curie Actions (MSCA) que visa o apoio formação e ao desenvolvimento da carreira, 28 de junho de 2018 5. Acordo de cooperação entre a Universidade Sun Yat-Sen e a ICRANet, 4 de julho de 2018 6. Cerimônia de encerramento do projeto “Do talento e da curiosidade. Quando a águia e o pássaro voam juntos” - Apresentação dos resultados, 4 de maio de 2018 7. Relatório técnico-científico do projeto “Do talento e da curiosidade. Quando a águia e o pássaro voam juntos” (ICRA,ICRANET, Fundação Marco Besso, ECIPA) 8. Parabéns ao Professor Gregory Vereshaghin, membro do corpo docente da ICRANet, por ter recebido o título de Doutor em Ciências (DSc) em Física Teórica, 13 de junho de 2018 9. Seminários no centro da ICRANet em Pescara 10. Visitas científicas à ICRANet 11. Últimas publicações
1. O trabalho de C.R. Argüelles, A. Krut, J.A. Rueda, R. Ruffini “Novel constraints on
fermionic dark matter from galactic observables I: The Milky Way” acaba de ser
aceites para publicação na revista Physics of the Dark Universe, 12 de julho de 2018
Since near a century already, Astronomers ans Asrtrophysists have been gathering and analyzing data coming from galaxies, either small, or large ellipticals, or clumped in large clusters; to realize that about the 85% of the matter content of the Universe cannot be made of any of the building blocks we know (such as electrons, protons, neutrons, or its combinations). They came to the conclusion that the gravity exerted by all these possible known forms of matter, as combined in stars, gas or dust, is not enough to explain the observed stability and the kinematical properties in galaxies: an extra matter content was needed, called dark matter (DM).
A consensus has been reached within the scientific community about the nature of the DM, pointing towards an unknown fundamental particle created at the dawn of times. These particles would have started to gather together due to its own self-gravity into many different clumps of matter, dubbed as DM halos. Such pristine agglomerations are spherical configurations which constitute the progenitors of the galaxies we see today, with the halo component spreading typically about ten times the extension of the bright and normal matter composing the disk (as in the case of our home, the Milky Way). An important open question in the field, is precisely how this DM is distributed along a given galaxy, as well as the exact nature of the particle constituting the DM. The traditional approach to tackle this issue is given in terms of big numerical simulations involving a large amount of classical point masses. While such simulations provide the needed dark mass to account for the rotation curve of a galaxy, it has several problems on smaller scales below 10 kpc when confronted with observations. 
For the first time, the authors in [1] have presented an alternative approach to this problem, which allows to consider the quantum nature of the dark constituents as well as the particle mass dependence, directly in the DM profiles. Such a model consists in solving the equations of a self-gravitating gas of elementary neutral fermions at finite temperature allowing for escape of particle effects. The theory has been recently applied to the case of our own Galaxy, which is certainly the best benchmark to test it, given the vast and precise amount of data available to the date. For particle masses in the range of few 10 to 100 keV (see Figure), the solutions obtained by the authors provide the right description for the rotation curve of the Galactic halo, and predict at the same time, a dense and compact core of quantum nature harbored at the center. The key novelty of such dark matter core, is the possibility to explain the dynamics of the closest star orbiting around the SgrA* Galaxy center, without the need to introduce a super massive black hole (BH). Read more: https://doi.org/10.1016/j.dark.2018.07.002
2. 15o Encontro Marcel Grossmann (MG15) – Roma, 1-7 de julho de 2018
O décimo quinto Encontro Marcel Grossmann sobre últimos desenvolvimentos no campo da Relatividade Geral
Teorética e Experimental, Astrofísica e Teorias Relativistas de Campo (MG15), teve lugar de 1 a 7 de julho de 2018 no
campus da Universidade “Sapienza” em Roma. O encontro foi muito além das expectativas e voltou a confirmar a sua
liderança no campo da Astrofísica Relativística, cimentada ano após ano desde 1985 pelo grupo ICRA da Sapienza, e
nos últimos anos também pela colaboração do ICRANet de Pescara.
Fig. 1 - MG15 foto de grupo na Aula Magna, Universidade Sapienza, Roma O MG15 contou com a participação de mais de 800 cientistas de 70 países de todo o mundo. Os participantes apresentaram seus mais recentes trabalhos sobre a compreensão do Universo a partir das equações da relatividade geral de Albert Einstein em mais de uma centena de sessões paralelas. Graças ao apoio financeiro fornecido pelo IUPAP, ICTP and ESA, muitos cientistas de países em vias de desenvolvimento tiveram a oportunidade de participar do MG15. As inscrições no local começaram no domingo, 1 de Julho, e partir das 10:00 h até 19:00 h. Na segunda, dia 2 de Julho, teve lugar a cerimônia oficial de abertura da Conferência, que contou com a presença do Professor Eugenio Gaudio, Reitor da Universidade “Sapienza”, e a cerimônia de entrega dos Prêmios Marcel Grossmann, veja- se: https://youtu.be/Mz5ZY0WzTDQ. Neste ano, os Prêmios Institucionais foram para: * A Colaboração Científica Planck (ESA), concedido a Jean-Loup Puget, chefe do Instrumentos de Altas Frequências (HFI) "por obter restrições importantes nos modelos inflacionários do Universo e nível da sua não- Gaussianidade primordial; pelas medidas com precisões sem precedentes do efeito de lentes gravitacionais na Radiação Cósmica de Fundo (CMB) devido às estruturas de larga escala e correspondente polarização-B da CMB, e o carimbo na CMB do gás nos aglomerados de galáxias; por ter obtido informações únicas sobre o tempo de re-ionização do nosso universo e a distribuição e propriedades da poeira cósmica e dos campo magnéticos na nossa galáxia". * Laboratório de Física Experimental Hansen na Universidade de Stanford, concedido ao prof. Leo Hollberg, diretor assistente do HEPL "ao HEPL por ter desenvolvido atividades interdepartamentais na Universidade de Stanford nas fronteiras da física fundamental, astrofísica e tecnologia".
Os prêmios individuais foram para: * Lyman Page "pelo desenvolvimento das ferramentas teóricas na investigação, por meio da CMB, da primeira aparição eletromagnética observável do nosso Universo". * Rashid Alievich Sunyaev "for the development of theoretical tools in the scrutinising, through the CMB, of the first observable electromagnetic appearance of our Universe". * Shing-Tung Yau "pela prova da positividade da massa total na teoria da relatividade geral e por aperfeiçoar o conceito de massa quase-local, por sua prova da conjectura de Calabi, pelo seu contínuo papel inspirador no estudo da física de buracos negros".
Aproximadamente 26 sessões paralelas aconteceram nas tardes de cada dia da conferência, dentro do campus da universidade e no prédio vizinho CNR, cobrindo os seguintes tópicos: acreção, teorias alternativas, buracos negros, sistemas binários, estrelas de bósons, radiação cósmica, cordas cósmicas, energia escura e estrutura a larga escala, matéria escura, educação, universo primordial, explosões de raios gama, ondas gravitacionais, física de altas energias, história da relatividade, estrelas de nêutrons, testes de precisão, gravitação quântica, campos intensos e anãs brancas. Nas sessões da tarde abertas ao público foram proferidas palestras por Jeremiah Ostriker, Malcolm Longair, Marc Henneaux, Jean-Loup Puget, Lyman Page e Anne Archibald. Foram organizados também muitos eventos sociais: na terça, à noite, os professores e pequisadores da Universidade Sun Yat-Sen, na China, organizaram o evento “SYSU Connection reception” e os participantes do MG15 tiveram a oportunidade de assistir à apresentação da referida Universidade bem como presenciar à celebração da cerimônia de assinatura do acordo de cooperação entre a SYSU e a ICRANet. O Jantar Oficial teve lugar no maravilhoso Edifício Colonna localizado no coração de Roma, na noite da quarta; nesta ocasião, Claudia Graf-Grossmann, neta de Marcel Grossmann, apresentou a biografia de seu avô, cujo prefácio foi editado graças à colaboração com o Prof. Ruffini. Nesse mesmo dia, houve a possibilidade de os interessados visitarem Galleria Colonna, a coleção privada do palácio. 
Durante toda a semana da conferência, foi reservado um espaço para as editoras (Cambridge University Press, IOP Publishing, Universe e Springer Nature); a televisão estatal chinesa documentou o evento, veja-se: https://youtu.be/KbTgZuPEGgc e https://youtu.be/cbYbSn2BoFE O ICRA e a ICRANet estão cuidando dos proceedings, que serão publicados pela World Scientific, Singapore, em 2019, em modalidade e-book com acesso aberto. Materiais para consulta: * Intervista com o Prof. Ruffini: https://www.youtube.com/watch?v=i24U7SGoVAc&feature=youtu.be; * Site do MG15: http://www.icra.it/mg/mg15
3. Visita do Prof. Ruffini à Albânia, 23-24 de maio de 2018
Durante a visita na Albânia nos dia 23 e 24 de maio de 2018 e graçãs à colaboração com a professora Mimoza Hafizi, o
Professor Ruffini encontrou o Prof. Dr. Mynyr Koni, Reitor da Universidade de Tirana para dialogar sobre a
possibilidade da Universidade de Tirana se tornar membro oficial do IRAP PhD, com todos os direitos e privilégios
previstos pelo Estatuto do IRAP PhD. Essa visita foi organizada após a proposta unânime ser avançada durante a
reunião do corpo docente do IRAP PhD do dia 30 de abril de 2018.
4. Prof. Ruffini nomeado membro do Comitê consultivo Horizonte 2020 para o programa
Marie Skłodowska-Curie Actions (MSCA) que visa o apoio formação e ao
desenvolvimento da carreira, 28 de junho de 2018
O Prof. Ruffini foi nomeado oficialmente “Membro do Comitê Consultivo Horizonte 2020 para o programa Marie Skłodowska-Curie Actions (MSCA) que visa o apoio formação e ao desenvolvimento da carreira, para o período de 2018 a 2020 (3o mandato). A Comissão Europeia renovou a composição dos seus Comitês Consultivos que fornecem informações externas de alta qualidade para ajudar, avaliar, enriquecer e manter atualizadas suas reflexões e idéias para o monitoramento e o desenvolvimento do Programa Horizonte 2020 e o prof. Ruffini foi selecionado por seu conhecimento específico e experiência no campo da ciência. A sua biografia foi incluída no panfleto “Quem é quem” do referido grupo. A nomeação ocorreu por ocasião da 12a reunião do Grupo Consultivo da MSCA, realizada em Bruxelas em 28 de junho de 2018: esta foi a primeira reunião do grupo sob a sua terceira configuração para o programa Horizonte 2020. O MSCA apoia financeiramente os pesquisadores em todas as etapas de suas carreiras, independentemente de nacionalidades e disciplinas. O financiamento pode ser atribuído a pesquisadores individuais, redes, programas de intercâmbio de pessoal e programas de doutorado / pós-doutorado. Além de fornecer apoio financeiro para pesquisa, o MSCA permite que os cientistas obtenham experiência internacional, intersetorial e interdisciplinar e aperfeiçoem sua formação científica com competências transferíveis que aumentem sua empregabilidade e suas perspectivas de carreira. Para mais informações acesse: http://ec.europa.eu/research/mariecurieactions/
5. Acordo de cooperação entre a Universidade Sun Yat-Sen e a ICRANet, 4 de julho de 2018
No dia 4 de Julho de 2018, a ICRANet celebrou um acordo de cooperação com a Universidade Sun Yat-Sen, localizada
em Guangzhou, na China. O acordo foi assinado pelo Prof. Luo Jun, Presidente da Universidade Sun Yat-Sen, e pelo
Prof. Remo Ruffin, Diretor da ICRANet. Além do Prof. Luo Jun, que foi um dos conferencistas das Sessões Plenárias
do MG15, muitos foram os professores e os pesquisadores da Universidade Sun Yat-Sen que participaram do Encontro
e que aproveitaram a oportunidade para apresentarem o Instituto durante o evento “SYSU Connection reception” bem
como presenciar à celebração da cerimônia de assinatura do referido acordo.
O acordo, que terá validade de 5 anos, visa prestar reciprocamente assessoria na promoção de atividade conjuntas de investigação teórica e observacional no campo da Astrofísica Relativística, realizar programas de intercâmbio de docentes, investigadores, estudantes de pós-doutorado e estudantes de doutorado bem como fomentar o desenvolvimento tecnológico, desenvolver os centros de dados para os dados atrofísicos em todas as faixas de frequência, organizar cursos de ensino e formação, desenvolver pesquisa inter-institucional nas áreas associadas aos programas de formação locais, e realizar publicações conjuntas. Para o texto do Acordo, acesse: http://www.icranet.org/documents/agreementICRANet-SunYatSenUniversity.pdf Para saber mais sobre a participação do prof. Luo Jun ao MG15 acesse: http://www.sysu.edu.cn/2012/en/news/news01/32725.htm
6. Cerimônia de encerramento do projeto “Do talento e da curiosidade. Quando a águia e
o pássaro voam juntos” - Apresentação dos resultados, 4 de maio de 2018
Official program of the closing ceremony event - ICRANet, 4 May 2018 On Friday 4 May 2018, ICRANet center in Pescara hosted the closing ceremony of the project supported by the Italian Ministry of Education, University and Research (MIUR) “Del Talento e della curiosità. Quando l’aquila e il passero volano insieme” (“Of Talent and Curiosity. When the eagle and the sparrow fly together”), in collaboration with the Besso Foundation, ICRA and ECIPA. The event was also attended by more than 50 students from the classes 4D and 4I of “Liceo scientifico Galileo Galilei” of Pescara, under the supervision of Professors Gabriele Fraternali and Tiziana Pompa. This event concluded a series of other initiatives developed since last year in the framework of this project, and was devoted to present the attended results and the possible future perspectives. The referents of the event were Professor Remo Ruffini, director of ICRANet and Mr. Marco Trisi, Director of ECIPA. After a press conference, the two referents resumed to the highlight of the past events occurred in the framework of the project, and showed them some videos realized on those occasions. Namely, the videos concerned the two exhibitionsF on “Einstein, Fermi and Heisenberg and the birth of Relativistic Astrophysics” and on “ICRANet and China” held in Besso Foundation (Rome) from 12 December 2017 to 12 January 2018 and the three seminars organized in parallel on 12 December 2017, 8 and 12 January 2018. At the end of this presentations, the students took the floor to present the scientific instruments they produced on their own in the framework of this project.
To conclude the event, Professor Zurab Berezhiani from the Department of Physical and Chemical Sciences of University of L'Aquila, gave an important seminar titled "Parallel dark world" at ICRANet center in Pescara. In this context, he discussed the possibility that dark matter is a sort of "baryonic" matter from parallel/mirror hidden sector of particles which can be exactly identical to that of ordinary particles, or represent its somewhat deformed version. Possible interaction processes between ordinary and dark particles are of particular interest since they can be at the origin of baryogenesis and dark baryogenesis and naturally explain why ordinary and dark matter fractions in the Universe are comparable. On the other hand, these interactions can be tested at laboratories via specific low-cost experiments. Please, see the link: http://www.icranet.org/index.php?option=com_content&task=blogcategory&id=89&Itemid=781
7. Technical-scientific report of the project "Del Talento e della curiosità. Quando l'aquila e il passero volano insieme" (ICRA,ICRANET, Fondazione Marco Besso, ECIPA)
Among the objects that have successfully followed the development of human being, the most significant and important has been the "Crab Nebula", chosen as symbol of the project. Discovered in 1054 as a “guest star”, it is now called “Crab Nebula” for its morphological appearance, similar to a crab, which has inside a Pulsar NPO532, which rotates with a period of 33 milliseconds and which in 1968 was identified as a rotating neutron star.
Please, look at Figure 12 where are: I. The Chinese writing concerning the discovery of the "guest star", registered in July 1054 from Chinese, Korean and Japanese astronomers; II. The splendid image of the Crab Nebula made by the Hubble Space Telescope in 2014 with its filamentary structures, still expanding today with velocity about 250 km / sec; III. The X-ray emission from the Crab pulsar and its wind nebula observed by the satellite CHANDRA. This has been the thread of the exhibitions organized by ICRA and ICRANet, whose major analysis carried on in the last 50 years have been devoted to the comprehension of Neutron Stars, at the discovery of the first Black Hole (see Figure 13) and, recently, to the physics of Gamma Ray Bursts. Those have allowed to join and light up the most distant and darkest parts of the Universe, going back to its early stages and to the Big Bang. The energy emitted by a GRB is equivalent to the one emitted by a billion of galaxies, each consisting of 100 billions of stars, even if only for a time duration of about hundreds of seconds.
The comprehension of those phenomena has a long and progressive history, in which relevant events have became possible thanks to the cooperation among East and West and to fundamental conceptual revolutions introduced by three "giants": Albert Einstein, Werner Heisenberg and Enrico Fermi. All those have been possible also thanks to the special relationship between Italy and China, to the crucial role played by Italy in the Albert Einstein’s formulation of general and special relativity, to the collaboration among Michele Besso and Marcel Grossmann with the major Italian mathematicians (as Ricci Curbastro and Tullio Levi Civita), and thanks also to the revolutionary role of Fermi in Cosmology, still unknown to the public. To check the material of the 2 exhibitions "ICRANet and China" and "Einstein, Fermi and Heisenberg: the birth of Relativistic Astrophysics", see: http://www.fondazionemarcobesso.it/3362/inaugurazione-mostre-einstein-fermi-e-heisenberg-e-la-nascita-della-astrofisica-relativistica-e-icranet-e-cina-2/ To read the biography "Marcel Grosmann. For the love of Mathematics", please see: https://www.amazon.it/Marcel-Grossmann-Mathematics-Springer-Biographies-ebook/dp/B07DMD4VNH/ref=sr_1_1?ie=UTF8&qid=1532701370&sr=8-1&keywords=Marcel+Grossmann+For+the+Love+of+Mathematics (English) https://www.amazon.it/Marcel-Grossmann-Aus-Liebe-Mathematik/dp/3905894327/ref=sr_1_fkmr0_1?ie=UTF8&qid=1532701370&sr=8-1-fkmr0&keywords=Marcel+Grossmann+For+the+Love+of+Mathematics (German) In the framework of this project, the books "Fermi e l'Astrofisica" (being printed in Singapore) and "Einstein, Heisenberg and Fermi and the birth of Relativistic Astrophysics", have been completed. Several chapters of those books have been presented during the conferences held in the framework of the project from Professor Roy Patrick Kerr, Crafoord Prize for Astronomy 2016, awarded by the King of Sweden (see Figure 14). 
Figure 14 – Prof. Roy Patrick Kerr, Crafoord Prize for Astronomy 2016, during his conference “Cracking the Einstein code”, held at Fondazione Besso in Rome. In those conferences, held at Fondazione Besso and Sapienza University in Rome, several eminent astrophysics (see Figures 15, 16, 17, 18) as Marco Tavani (https://youtu.be/E7t0TkuK6Bc), Massimo Della Valle (https://youtu.be/9rjA-5ZgkOE), Fulvio Ricci (https://youtu.be/BXUH2hxlZGU), Roy Kerr (https://youtu.be/9rjA-5ZgkOE), Paolo de Bernardis (https://youtu.be/dJGBH6cuaXA) and Paolo Giommi, as well as several ICRANet PhD students (see Figures 19, 20, 21, 22, 23), have presented their high levels scientific reports, filmed and broadcasted in order so that can be used for important researches in the following years.
8. Parabéns ao Professor Gregory Vereshaghin, membro do corpo docente da ICRANet, por ter recebido o título de Doutor em Ciências (DSc) em Física Teórica, 13 de junho
de 2018
É com grande prazer que anunciamos que no dia 12 de junho de 2018 o Professor Gregory Vereshaghin, membro do corpo docente da ICRANet recebeu o título de Doutor em Ciências (DSc) em Física Teórica, como anunciado pela Comissão Superior de Atestado (VAK) da Bielorrússia (http://www.vak.org.by/node/4418). A dissertação de doutorado intitulada “Kinetics, hydrodynamics and radiation of relativistic plasma” foi defendida no dia 27 de Dezembro de 2017 (http://vak.org.by/node/3942). O Professor Gregory Vereshchagin tornou-se um dos poucos jovens pesquisadores bielorrussos com menos de 40 anos premiados com o mais alto grau científico em seu país. 
Fig. 23 - o Professor Gregory Vereshchagin durante sua dissertação de doutorado no dia 27 de Dezembro de 2017.
9. Seminários no centro da ICRANet em Pescara
* Seminário dado pelo professor Shadi Tahvidar-Zadeh
* Seminário dado por Sergio Andrés Vallejo Peña, dia 24 de Julho 
No dia 24 de julho, Sergio Andrés Vallejo Peña, um visitante de doutorado da Universidade de Antioquia (UDEA), Colômbia, deu dois seminários sobre "Os efeitos da anisotropia e não adiabaticidade na evolução da perturbação da curvatura" (https://arxiv.org/abs/1804.05005) e "O MESS das perturbações cosmológicas". (https://arxiv.org/abs/1806.01941). * Seminário dado por Mikalai Prakapenia, 24 de Julho 
No dia 24 de julho, Mikalai Prakapenia (Pesquisador do ICRANet de Minsk e doutorando na Universidade Estatal da Bielorrúsia) deu um seminário importante com o título "Termalização de um plasma de elétrons-pósitrons com degenerescência quântica". Ele reportou suas análises do não equilíbrio num processo de termalização de elétrons-pósitrons-fótons, levando em conta correções quânticas em ambos os casos relativístico e não relativístico. Integrais em processos de colisão foram calculadas a partir de elementos de matriz exatos em QED para todas as interações binárias e triplas no plasma. Foi mostrado que no caso não relativístico as taxas de interações binárias dominam as interações triplas, resultando no estabelecimento de equilíbrio cinético antes do térmico, em acordo com estudos anteriores. Por outro lado, no caso relativístico as taxas de interações triplas são rápidas o bastante para se impedir o estabelecimento de equilíbrio cinético. Foi mostrado também que os processos de termalização são fortemente dependentes da degenerescência quântica do estado inicial, mas não dependem da composição do plasma.
10. Visitas científicas à ICRANet
* Dr. Sonila Boçi (Universidade de Tirana – Albânia) 30 de Abril – 13 de maio
* Professor Clovis Achy Soares Maia (Universidade de Brasília – Brasil), 7 – 14 de Julho de 2018 * Estudantes de Doutorado Sílvia Pereira Nunes, Ronaldo Vieira Lobato e Marcelo Montenegro Lapola ((Instituto Tecnológico de Aeronáutica de São José dos Campos, SP – Brasil), 7 – 12 de Julho * Professor Shadi Tahvildar-Zadeh Rutgers, Universidade Estadual de Nova Jersey – USA), 17 – 30 de Junho * Soroush Shakeri (Universidade de Tecnologia de Isfahan – Irã), 19 de Junho – 17 de Julho * Prof. Mathews Grant (Centro de Astrofísica na Universidade de Notre Dame – USA), 7 – 9 de Julho * Professor Wenbin Lin (Escola de Ciência Física e Tecnologia, da Univesidade do Sudoeste Jiaotong – China), 8 – 14 de Julho * Professor Hyung Won Lee (Universidade Inje – Coreia do Sul), 16 de Julho – 15 de Agosto de 2018 * Sergio Andrés Vallejo Peña (Universidade de Antioquia – Colombia), 1 de Julho – 9 de Setembro * Mikalai Prakapenia (Centro ICRANet-Minsk e Universidade Estatal da Bielorrússia, Bielorrússia), 1 – 27 de Julho
Na sequência da assinatura do acordo entre a ICRANet e a Al-Farabi Kazakh National University, dois grupos de estudantes cazaques visitaram o centro da ICRANet em Pescara, sob a supervisão do professor Medeu Abishev. Primeiro grupo de estudantes, de 11 a 25 de Junho: Fariza Aitzhan, Makpal Akhmetzhanova, Albina Bazarova, Aizhan Duysenbaeva, Mamak Tangsholpan, Ernat Nurtazin, Balzhan Mamadkarimova and Tileuberdi Akhat). Segundo grupo de estudantes, de 30 de Junho a 11 de Julho: Sadirkhanov Zhandos, Abdramanova Gulbanu, Assel Kuanysh, Anel Imangaliyeva, Symbat Nurakhmetova, Anapiya Meruyert, Zaltay Aklen, Gaukhar Askhanova, Niyazov Kaiyrzhan, Yesbol Meirambekuly, Botakoz Seifullina and Fatima Dankenova. A second group came from 30 June to 11 July, and was composed by: Sadirkhanov Zhandos, Abdramanova Gulbanu, Assel Kuanysh, Anel Imangaliyeva, Symbat Nurakhmetova, Anapiya Meruyert, Zaltay Aklen, Gaukhar Askhanova, Niyazov Kaiyrzhan, Yesbol Meirambekuly, Botakoz Seifullina and Fatima Dankenova.
11. Recent publications
S. Gasparyan, N. Sahakyan, V. Baghmanyan, D. Zargaryan, "On the multi-wavelength Emission from CTA 102", accepted for publication on The Astrophysical Journal, on 8 July 2018.
We report on broadband observations of CTA 102 (z=1.037) during the active states in 2016-2017. In the γ-ray band, Fermi LAT observed several prominent flares which followed a harder-when-brighter behavior: the hardest photon index Γ=1.61±0.10 being unusual for FSRQs. The peak γ-ray flux above 100 MeV (3.55±0.55)×10−5 photon cm−2s−1 observed on MJD 57738.47 within 4.31 minutes, corresponds to an isotropic γ-ray luminosity of Lγ=3.25×1050ergs−1, comparable with the highest values observed from blazars so far. The analyses of the Swift UVOT/XRT data show an increase in the UV/optical and X-ray bands which is contemporaneous with the bright γ-ray periods. The X-ray spectrum observed by Swift XRT and NuSTAR during the γ-ray flaring period is characterized by a hard photon index of ∼1.30. The shortest e-folding time was 4.08±1.44 hours, suggesting a very compact emission region R≤δ×2.16×1014 cm. We modeled the spectral energy distribution of CTA 102 in several periods (having different properties in UV/optical, X-ray and γ-ray bands) assuming a compact blob inside and outside the BLR. We found that the high-energy data are better described when the infrared thermal radiation of the dusty torus is considered. In the flaring periods when the correlation between the γ-ray and UV/optical/X-ray bands is lacking, the γ-ray emission can be produced from the interaction of fresh electrons in a different blob, which does not make a dominant contribution at lower energies. Link: https://arxiv.org/abs/1807.02869v1 P. Padovani, P. Giommi, E. Resconi, T. Glauch, B. Arsioli, N. Sahakyan, M. Huber,“Dissecting the region around IceCube-170922A: the blazar TXS 0506+056 as the first cosmic neutrino source”, accepted for publication in MNRAS on 12 July 2018. We present the dissection in space, time, and energy of the region around the IceCube-170922A neutrino alert. This study is motivated by: (1) the first association between a neutrino alert and a blazar in a flaring state, TXS 0506+056; (2) the evidence of a neutrino flaring activity during 2014 - 2015 from the same direction; (3) the lack of an accompanying simultaneous γ-ray enhancement from the same counterpart; (4) the contrasting flaring activity of a neighbouring bright γ-ray source, the blazar PKS 0502+049, during 2014 - 2015. Our study makes use of multi-wavelength archival data accessed through Open Universe tools and includes a new analysis of Fermi-LAT data. We find that PKS 0502+049 contaminates the γ-ray emission region at low energies but TXS 0506+056 dominates the sky above a few GeV. TXS 0506+056, which is a very strong (top percent) radio and γ-ray source, is in a high γ-ray state during the neutrino alert but in a low though hard γ-ray state in coincidence with the neutrino flare. Both states can be reconciled with the energy associated with the neutrino emission and, in particular during the low/hard state, there is evidence that TXS 0506+056 has undergone a hadronic flare with very important implications for blazar modelling. All multi-messenger diagnostics reported here support a single coherent picture in which TXS 0506+056, a very high energy γ-ray blazar, is the only counterpart of all the neutrino emissions in the region and therefore the most plausible first non-stellar neutrino and, hence, cosmic ray source. Link: https://arxiv.org/abs/1807.04461 T. Hayashinaka, S. Xue, “Physical renormalization condition for de Sitter QED”, Published in Rapid communication section of Phys. Rev. D 97, 105010, on 13 February 2018. We considered a new renormalization condition for the vacuum expectation values of the scalar and spinor currents induced by a homogeneous and constant electric field background in de Sitter spacetime. Following a semiclassical argument, the condition named maximal subtraction imposes the exponential suppression on the massive charged particle limit of the renormalized currents. The maximal subtraction changes the behaviors of the induced currents previously obtained by the conventional minimal subtraction scheme. The maximal subtraction is favored for a couple of physically decent predictions including the identical asymptotic behavior of the scalar and spinor currents, the removal of the infrared (IR) hyperconductivity from the scalar current, and the finite current for the massless fermion. Link: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.105010 C.R. Argüelles, A. Krut, J.A. Rueda, R. Ruffini, “Novel constraints on fermionic dark matter from galactic observables I: The Milky Way”, accepted for publication on Physics of the Dark Universe, Volume 21, on 12 July 2018. We have recently introduced a new model for the distribution of dark matter (DM) in galaxies based on a self-gravitating system of massive fermions at finite temperatures, the Ruffini–Argüelles–Rueda (RAR) model. We show that this model, for fermion masses in the keV range, explains the DM halo of the Galaxy and predicts the existence of a denser quantum core at the center. We demonstrate here that the introduction of a cutoff in the fermion phase-space distribution, necessary to account for the finite Galaxy size, defines a new solution with a central core which represents an alternative to the black hole (BH) scenario for SgrA*. For a fermion mass in the range mc2=48-345 keV, the DM halo distribution is in agreement with the Milky Way rotation curve data, while harbors a dense quantum core of about 4x106 solar masses within the S2-star pericenter. Link: https://www.sciencedirect.com/science/article/pii/S2212686418300815 M.A. Prakapenia, I.A.Siutsou, G.V. Vereshchagin, “Numerical scheme for treatment of Uehling–Uhlenbeck equation for two-particle interactions in relativistic plasma, accepted for publication on the Journal of Computational Physics, on 4 July 2018. We present a new efficient method to compute Uehling–Uhlenbeck collision integral for all two-particle interactions in relativistic plasma with drastic improvement in computation time with respect to existing methods. Plasma is assumed isotropic in momentum space. The set of reactions consists of: Moeller and Bhabha scattering, Compton scattering, two-photon pair annihilation, and two-photon pair production, which are described by QED matrix elements. In our method exact energy and particle number conservation laws are fulfilled. Reaction rates are compared, where possible, with the corresponding analytical expressions and convergence of numerical rates is demonstrated. Link: https://www.sciencedirect.com/science/article/pii/S0021999118304650?via%3Dihub B. Arsioli, U. Barres de Almeida, E. Prandini, B. Fraga, L. Foffano, “Extreme & High Synchrotron Peaked Blazars at the limit of Fermi-LAT detectability: the γ-ray spectrum of 1BIGB sources”, published on Monthly Notices of the Royal Astronomical Society, sty1975, on 24 July 2018. We present the 1-100 GeV spectral energy distribution for a population of 148 high-synchrotron-peaked blazars (HSPs) recently detected with Fermi-LAT as part of the First Brazil-ICRANet Gamma-ray Blazar catalogue (1BIGB). Most of the 1BIGB sources have their γ-ray spectral properties presented here for the first time, representing a significant new extension of the γ-ray blazar population. Since our sample was originally selected from an excess signal in the 0.3 - 500 GeV band, the sources stand out as promising TeV blazar candidates, potentially in reach of the forthcoming very-high-energy (VHE) γ-ray observatory, CTA. The flux estimates presented here are derived considering PASS8 data, integrating over more than 9 years of Fermi-LAT observations. We also review the full broadband fit between 0.3-500 GeV presented in the original 1BIGB paper for all sources, updating the power-law parameters with currently available Fermi-LAT dataset. The importance of these sources in the context of VHE population studies with both current instruments and the future CTA is evaluated. To do so, we select a subsample of 1BIGB sources and extrapolate their γ-ray SEDs to the highest energies, properly accounting for absorption due to the extragalactic background light. We compare those extrapolations to the published CTA sensitivity curves and estimate their detectability by CTA. Two notable sources from our sample, namely 1BIGB J224910.6-130002 and 1BIGB J194356.2+211821, are discussed in greater detail. All γ-ray SEDs, are made publicly available via the Brazilian Science Data Center (BSDC) service, maintained at CBPF, in Rio de Janeiro. Link: https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/sty1975/5057880 R. Ruffini, J. Rodriguez, M. Muccino, J. A. Rueda, Y. Aimuratov, U. Barres de Almeida, L. Becerra, C. L. Bianco, C. Cherubini, S. Filippi, D. Gizzi, M. Kovacevic, R. Moradi, F. G. Oliveira, G. B. Pisani, and Y. Wang, “On the Rate and on the Gravitational Wave Emission of Short and Long GRBs” published on The Astrophysical Journal, Volume 859, Number 1 on 18 May 2018. On the ground of the large number of gamma-ray bursts (GRBs) detected with cosmological redshift, we classified GRBs in seven subclasses, all with binary progenitors which emit gravitational waves (GWs). Each binary is composed of combinations of carbon–oxygen cores (COcore), neutron stars (NSs), black holes (BHs), and white dwarfs (WDs). The long bursts, traditionally assumed to originate from a BH with an ultrarelativistic jetted emission, not emitting GWs, have been subclassified as (I) X-ray flashes (XRFs), (II) binary-driven hypernovae (BdHNe), and (III) BH–supernovae (BH–SNe). They are framed within the induced gravitational collapse paradigm with a progenitor COcore–NS/BH binary. The SN explosion of the COcore triggers an accretion process onto the NS/BH. If the accretion does not lead the NS to its critical mass, an XRF occurs, while when the BH is present or formed by accretion, a BdHN occurs. When the binaries are not disrupted, XRFs lead to NS–NS and BdHNe lead to NS–BH. The short bursts, originating in NS–NS, are subclassified as (IV) short gamma-ray flashes (S-GRFs) and (V) short GRBs (S-GRBs), the latter when a BH is formed. There are (VI) ultrashort GRBs (U-GRBs) and (VII) gamma-ray flashes (GRFs) formed in NS–BH and NS–WD, respectively. We use the occurrence rate and GW emission of these subclasses to assess their detectability by Advanced LIGO-Virgo, eLISA, and resonant bars. We discuss the consequences of our results in view of the announcement of the LIGO/Virgo Collaboration of the source GW 170817 as being originated by an NS–NS. Link: http://iopscience.iop.org/article/10.3847/1538-4357/aabee4/meta D. Bini, T. Damour, A. Geralico, “Spin-orbit precession along eccentric orbits: Improving the knowledge of self-force corrections and of their effective-one-body counterparts”, published on Phys. Rev. D 97, 104046 (2018) on 25 May 2018. The (first-order) gravitational self-force correction to the spin-orbit precession of a spinning compact body along a slightly eccentric orbit around a Schwarzschild black hole is computed through the ninth post-Newtonian order, improving recent results by Kavanagh et al. [Phys. Rev. D 96, 064012 (2017).] This information is then converted into its corresponding Effective-One-Body counterpart, thereby determining several new post-Newtonian terms in the gyrogravitomagnetic ratio gS∗. Link: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.104046 D. Bini, T. Damour, A. Geralico, C. Kavanagh, “Detweiler’s redshift invariant for spinning particles along circular orbits on a Schwarzschild background”, published on Phys. Rev. D 97, 104022 (2018) on 18 May 2018. We study the metric perturbations induced by a classical spinning particle moving along a circular orbit on a Schwarzschild background, limiting the analysis to effects which are first order in spin. The particle is assumed to move on the equatorial plane and has its spin aligned with the z-axis. The metric perturbations are obtained by using two different approaches, i.e., by working in two different gauges: the Regge-Wheeler gauge (using the Regge-Wheeler-Zerilli formalism) and a radiation gauge (using the Teukolsky formalism). We then compute the linear-in-spin contribution to the first-order self-force contribution to Detweiler's redshift invariant up to the 8.5 post-Newtonian order. We check that our result is the same in both gauges, as appropriate for a gauge-invariant quantity, and agrees with the currently known 3.5 post-Newtonian results. Link: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.104022 |
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