Abrikosov, Gorkov, Dzyaloshinski, Methods of quantum field theory in statistical physics Fetter, Walecka, Quantum theory of many-particle systems T. Schaefer, Quark Matter, hep-ph/0304281. J. Kogut, M. Stephanov, The Phases of QCD, Cambridge University Press (2004). K. Rajagopal, F. Wilczek, The Condensed Matter Physics of QCD, hep-ph/0011333. J. Lattimer and M. Prakash, The Physics of Neutron Stars, astro-ph/0405262. D. Kaplan, Five lectures on effective field theory, nucl-th/0510023.
Dennis Edward Hyde, Letícia Pereira Alves, Daniel Rodrigues Costa Mello
et al.
This article presents the National Parks Astrotourism Potential Index (IASTRO), an innovative tool to evaluate and compare the potential for astro tourism in the 75 Brazilian national parks. IASTRO combines three crucial parameters: night sky quality, open sky probability, and tourism infrastructure, which encompasses the presence of guides and the availability of different experiences of overnight stays. The detailed methodology for data collection and IASTRO calculation is described, including the weighting of parameters, with night sky quality receiving greater weight for its fundamental importance for celestial observation. The results reveal a diverse distribution of IASTRO among the parks, highlighting those located in the Cerrado and Caatinga biomes, which present more favorable night sky and climatological conditions. The in-depth discussion explores the relationship between IASTRO and other factors, such as the number of visitors and the characteristics of the biomes, revealing an untapped potential for astro tourism in many national parks. The study also highlights the importance of tourism infrastructure and simulates how improvements in this aspect can boost astro tourism potential in various parks. The final considerations emphasize IASTRO as a valuable tool for protected area management and for the formulation of public policies, promoting the preservation of the starry sky and the development of astro tourism in a sustainable way. The article concludes that Brazil has enormous potential to become a world-class astro tourism destination, with its national parks offering exceptional conditions for celestial observation and connection with nature. This pioneering study contributes to the field of ecotourism by providing a comprehensive and innovative index to assess the astro tourism potential in national parks. IASTRO can be used by park managers, researchers, tourists, astronomy enthusiasts and policy makers to identify and prioritize parks with greater potential for this activity, assisting in the planning of actions and investments that promote the development of astro tourism in Brazil. In summary, the article presents an innovative index to assess the astro tourism potential in Brazilian national parks, highlighting the importance of night sky quality, open sky probability, and tourism infrastructure. The study reveals an untapped potential for astro tourism in many parks and highlights the importance of investments in tourism infrastructure to boost this activity. IASTRO is presented as a valuable tool for protected area management and for the formulation of public policies, aiming at the sustainable development of astro tourism in Brazil.
Bi-fidelity stochastic optimization has gained increasing attention as an efficient approach to reduce computational costs by leveraging a low-fidelity (LF) model to optimize an expensive high-fidelity (HF) objective. In this paper, we propose ASTRO-BFDF, an adaptive sampling trust region method specifically designed for unconstrained bi-fidelity stochastic derivative-free optimization problems. In ASTRO-BFDF, the LF function serves two purposes: (i) to identify better iterates for the HF function when the optimization process indicates a high correlation between them, and (ii) to reduce the variance of the HF function estimates using bi-fidelity Monte Carlo (BFMC). The algorithm dynamically determines sample sizes while adaptively choosing between crude Monte Carlo and BFMC to balance the trade-off between optimization and sampling errors. We prove that the iterates generated by ASTRO-BFDF converge to the first-order stationary point almost surely. Additionally, we demonstrate the effectiveness of the proposed algorithm through numerical experiments on synthetic problems and simulation optimization problems involving discrete event systems.
Desde tempos imemoriais que os seres humanos olham e tentam perceber o céu. Não sabiam bem o que eram aquelas luzes a brilhar e que se movimentavam de forma repetida. Hoje em dia parece muito fácil, mas demorou muito tempo a consolidar-se a imagem que atualmente temos do céu. E sobretudo, a sabermos qual era a sua composição química. Este artigo pretende fazer uma revisão de divulgação do conhecimento químico que temos do céu e mostrar que as informações químicas são indissociáveis do entendimento que temos hoje do universo.
Neste artigo explicamos o que são as ondas gravitacionais previstas pela teoria da relatividade geral de Einstein, falamos de suas fontes astrofísicas e cosmológicas e dos detectores que foram utilizados para a sua busca. Completamos o artigo com a menção aos detectores futuros, que estão sendo projetados para dar uma nova dimensão à astronomia de ondas gravitacionais e à astronomia multimensageira envolvendo ondas gravitacionais.
Discuto alguns aspectos do chamado “paradigma da luz cansada”, o qual representa uma das possíveis explicações para a dependência do desvio espectral para o vermelho de uma fonte cósmica distante com a sua distância até o observador. A mais popular representação fenomenológica do paradigma é apresentada em algum detalhe. Além disso, sendo o processo físico responsável pelo hipotético fenômeno ainda desconhecido, apresento também uma sugestão para a sua descoberta.
O objetivo deste artigo é mostrar o motivo de se considerar a matéria escura como ingrediente fundamental para o Universo. A existência da matéria escura é indispensável para formar as estruturas cósmicas que observamos como galáxias e aglomerados de galáxias. Apesar de ainda desconhecermos a natureza desta componente cósmica, pois ainda não a detectamos diretamente, o aspecto discutido neste trabalho é considerado um dos principais argumentos a favor da existência da matéria escura.
Tadayuki Takahashi, K. Mitsuda, Rich Kelley
et al.
The most characteristic high-energy phenomena in the Galactic center (GC) region is the presence of strong K-shell emission lines from highly ionized Si, S, Ar, Ca, Fe and Ni, which form the Galactic Center X-ray Emission (GCXE). These multiple lines suggest that the GCXE is composed of at least two plasmas with temperatures of ~1 and ~7 keV. The GCXE also exhibits the K-shell lines from neutral Si, S, Ar, Ca, Fe and Ni atoms. A debatable issue is the origin of the GCXE plasma; whether it is a diffuse plasma or integrated emission of many unresolved point sources such as cataclysmic variables and active binaries. Detailed spectroscopy for these lines may provide a reliable picture of the GCXE plasma. The origin of the K-shell lines from neutral atoms is most likely the fluorescence by X-rays from a putative past flare of Sgr A*. Therefore ASTRO-H may provide unprecedented data for the past light curve of Sgr A*. All these lines may provide key information for the dynamics of the GCXE, using possible Doppler shift and/or line broadening. This paper overviews these line features and the previous interpretation of their origin. We propose extended or revised science with the ASTRO-H observations of some select objects in the GC region.
In this paper, we demonstrate ASTRO-H's capability to measure the chemical evolution in the high-z (z <~ 3) universe by observing X-ray afterglows of gamma-ray bursts (GRBs) and distant Blazars. Utilizing these sources as background light sources, the excellent energy resolution of ASTRO-H/SXS allows us to detect emission and absorption features from heavy elements in the circumstellar material in the host galaxies, from the intergalactic medium (IGM) and in the ejecta of GRB explosions. In particular, we can constrain the existence of the warm-hot intergalactic material (WHIM), thought to contain most of the baryons at redshift of z < ~3, with a typical exposure of one day for a follow-up observation of a GRB afterglow or 300 ks exposure for several distant Blazars. In addition to the chemical evolution study, the combination of the SGD, HXI, SXI and SXS will measure, for the first time, the temporal behavior of the spectral continuum of GRB afterglows and Blazars over a broad energy range and short time scales allowing detailed modeling of jets. The ability to obtain these data from GRB afterglows will depend critically on the availability of GRB triggers and the capability of ASTRO-H to respond rapidly to targets of opportunity. At the present time it seems as if Swift will still be functioning normally during the first two years of ASTRO-H operations providing the needed triggering capability.
From a simple text interface to a graphical user interfaces—Astro-WISE provides the user with a wide range of possibilities to interact with the information system according to the user’s tasks and use cases. We describe a general approach to the interfacing of a scientific information system. We use this approach to create a number of services, which allows the user to browse the data stored in the system, to process the data and to exchange the newly created images and catalogs with the users within the system and wider astronomical community. Reusability of interfaces and services is another important feature of our approach. It reduces the time and resources spent to interface other information systems created from Astro-WISE.
We present a novel approach to quality control during the processing of astronomical data. Quality control in the Astro-WISE Information System is integral to all aspects of data handing and provides transparent access to quality estimators for all stages of data reduction from the raw image to the final catalog. The implementation of quality control mechanisms relies on the core features in this Astro-WISEEnvironment (AWE): an object-oriented framework, full data lineage, and both forward and backward chaining. Quality control information can be accessed via the command-line awe-prompt and the web-based Quality-WISE service. The quality control system is described and qualified using archive data from the 8-CCD Wide Field Imager (WFI) instrument (http://www.eso.org/lasilla/instruments/wfi/) on the 2.2-m MPG/ESO telescope at La Silla and (pre-)survey data from the 32-CCD OmegaCAM instrument (http://www.astro-wise.org/~omegacam/) on the VST telescope at Paranal.
The OmegaCAM wide-field optical imager is the sole instrument on the VLT Survey Telescope at ESO’s Paranal Observatory. The instrument, as well as the telescope, have been designed for surveys with very good, natural seeing-limited image quality over a 1 square degree field. OmegaCAM was commissioned in 2011 and has been observing three ESO Public Surveys in parallel since October 15, 2011. We use the Astro-WISE information system to monitor the calibration of the observatory and to produce the Kilo Degree Survey (KiDS). Here we describe the photometric monitoring procedures in Astro-WISE and give a first impression of OmegaCAM’s photometric behavior as a function of time. The long-term monitoring of the observatory goes hand in hand with the KiDS survey production in Astro-WISE. KiDS is observed under partially non-photometric conditions. Based on the first year of OmegaCAM operations it is expected that a ∼ 1–2 % photometric homogeneity will be achieved for KiDS.
This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential of three future large scale particle detectors proposed in Europe as next generation underground observatories. The proposed apparatuses employ three different and, to some extent, complementary detection techniques: GLACIER (liquid argon TPC), LENA (liquid scintillator) and MEMPHYS (water Cherenkov), based on the use of large mass of liquids as active detection media. The results of these studies are presented along with a critical discussion of the performance attainable by the three proposed approaches coupled to existing or planned underground laboratories, in relation to open and outstanding physics issues such as the search for matter instability, the detection of astrophysical neutrinos and geo-neutrinos and to the possible use of these detectors in future high intensity neutrino beams.