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Sample records for astrophysical plasma-dynamic explorer

  1. Relativistic Astrophysics Explorer

    CERN Document Server

    Kaaret, P E

    2003-01-01

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 6 m^2 equal to ten times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors.

  2. The Relativistic Astrophysics Explorer

    Science.gov (United States)

    Kaaret, P.

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 60,000 cm2 equal to ten times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors.

  3. Exploring Astrophysical Magnetohydrodynamics in the Laboratory

    Science.gov (United States)

    Manuel, Mario

    2014-10-01

    Plasma evolution in many astrophysical systems is dominated by magnetohydrodynamics. Specifically of interest to this talk are collimated outflows from accretion systems. Away from the central object, the Euler equations can represent the plasma dynamics well and may be scaled to a laboratory system. We have performed experiments to investigate the effects of a background magnetic field on an otherwise hydrodynamically collimated plasma. Laser-irradiated, cone targets produce hydrodynamically collimated plasma jets and a pulse-powered solenoid provides a constant background magnetic field. The application of this field is shown to completely disrupt the original flow and a new magnetically-collimated, hollow envelope is produced. Results from these experiments and potential implications for their astrophysical analogs will be discussed.

  4. Astrophysics and the exploration of the universe

    International Nuclear Information System (INIS)

    This special issue of Clefs CEA journal is entirely devoted to astrophysics and to the exploration and probing of the Universe. A first part of this dossier, described here, makes a status of our present day knowledge about stars, planets, galaxies, the Universe structure and dark matter. Content: 1 - Stars seed the Universe: What does the Sun tell us?, Probing stellar interiors, From the Sun to the stars, A tour of stellar nurseries, How heavy elements arise, How supernovae explode, Supernova remnants, High-energy objects - sources for astonishment, Focus: A Probing the Universe across the entire light spectrum; 2 - Planets: a dance of small bodies, swirling around up to the finale of their birth: How our world was born, The rings of Saturn: a magnificent research laboratory, Planetary cocoons; 3 - Galaxies: a richly paradoxical evolution: The active life of galaxies, A mysterious black hole, Elucidating the cosmic ray acceleration mechanism, Seeking out the great ancestors, The formation of galaxies: a story of paradoxes, The morphogenesis of galaxies; 4 - The Universe, a homogeneous 'soup' that has turned into a hierarchical structure: The grand thermal history of the Universe, The cosmic web, The formation of the structures of the Universe: the interplay of models, Does the Universe have a shape? Is it finite, or infinite?; 5 - Odyssey across the dark side of the Universe: The puzzle of dark matter, Astrophysics and the observation of dark matter, The theory of dark matter, Could dark matter be generated some day at LHC? A Universe dominated by dark energy, Astrophysics and the observation of dark energy, Theories of dark energy, The matter-antimatter asymmetry of the Universe; 6 - Journey into the lights of the Universe: Microwave - ESA Planck Surveyor, Submillimeter and infrared - ArTeMis, Herschel Space Observatory, VLT-VISIR, Cassini-CIRS, Visible - SoHo-GOLF, X-ray - XMM-Newton, Gamma ray - INTEGRAL, Fermi Gamma-Ray Space Telescope, HESS, EDELWEISS

  5. Astrophysics

    International Nuclear Information System (INIS)

    Volume 5 of the proceedings contains 62 papers of which 61 have been incorporated in INIS. They are divided by subject into several groups: early-type stars, late-type stars, binaries and multiple systems, theoretical considerations, ultraviolet stellar spectra, high energy astrophysics and binary stars. Many papers dealt with variable stars, star development and star models. (M.D.). 200 figs., 38 tabs., 1189 refs

  6. Astrophysics of the 21st Century - Exploring the Extreme Universe

    Science.gov (United States)

    Barbier, Louis M.

    2006-01-01

    This paper will give an overview of the NASA Universe Division Beyond Einstein program. The Beyond Einstein program consists of a series of exploratory missions to investigate the most important and pressing problems in modern-day astrophysics - including searches for Dark Energy and studies of the earliest times in the universe, during the inflationary period after the Big Bang. A variety of new technologies are being developed both in the science instrumentation these missions will use and in the spacecraft that will carry those instruments.

  7. Exploring the Digital Universe with Europe's Astrophysical Virtual Observatory

    Science.gov (United States)

    2001-12-01

    Vast Databanks at the Astronomers' Fingertips Summary A new European initiative called the Astrophysical Virtual Observatory (AVO) is being launched to provide astronomers with a breathtaking potential for new discoveries. It will enable them to seamlessly combine the data from both ground- and space-based telescopes which are making observations of the Universe across the whole range of wavelengths - from high-energy gamma rays through the ultraviolet and visible to the infrared and radio. The aim of the Astrophysical Virtual Observatory (AVO) project, which started on 15 November 2001, is to allow astronomers instant access to the vast databanks now being built up by the world's observatories and which are forming what is, in effect, a "digital sky" . Using the AVO, astronomers will, for example, be able to retrieve the elusive traces of the passage of an asteroid as it passes near the Earth and so enable them to predict its future path and perhaps warn of a possible impact. When a giant star comes to the end of its life in a cataclysmic explosion called a supernova, they will be able to access the digital sky and pinpoint the star shortly before it exploded so adding invaluable data to the study of the evolution of stars. Background information on the Astrophysical Virtual Observatory is available in the Appendix. PR Photo 34a/01 : The Astrophysical Virtual Observatory - an artist's impression. The rapidly accumulating database ESO PR Photo 34a/01 ESO PR Photo 34a/01 [Preview - JPEG: 400 x 345 pix - 90k] [Normal - JPEG: 800 x 689 pix - 656k] [Hi-Res - JPEG: 3000 x 2582 pix - 4.3M] ESO PR Photo 34a/01 shows an artist's impression of the Astrophysical Virtual Observatory . Modern observatories observe the sky continuously and data accumulates remorselessly in the digital archives. The growth rate is impressive and many hundreds of terabytes of data - corresponding to many thousands of billions of pixels - are already available to scientists. The real sky is being

  8. Breakthrough Capability for the NASA Astrophysics Explorer Program: Reaching the Darkest Sky

    Science.gov (United States)

    Greenhouse, Matthew A.; Benson, Scott W.; Falck, Robert D.; Fixsen, Dale J.; Gardner, Joseph P.; Garvin, James B.; Kruk, Jeffrey W.; Oleson, Stephen R.; Thronson, Harley A.

    2012-01-01

    We describe a mission architecture designed to substantially increase the science capability of the NASA Science Mission Directorate (SMD) Astrophysics Explorer Program for all AO proposers working within the near-UV to far-infrared spectrum. We have demonstrated that augmentation of Falcon 9 Explorer launch services with a 13 kW Solar Electric Propulsion (SEP) stage can deliver a 700 kg science observatory payload to extra-Zodiacal orbit. This new capability enables up to 13X increased photometric sensitivity and 160X increased observing speed relative to a Sun- Earth L2, Earth-trailing, or Earth orbit with no increase in telescope aperture. All enabling SEP stage technologies for this launch service augmentation have reached sufficient readiness (TRL-6) for Explorer Program application in conjunction with the Falcon 9. We demonstrate that enabling Astrophysics Explorers to reach extra-zodiacal orbit will allow this small payload program to rival the science performance of much larger long development time systems; thus, providing a means to realize major science objectives while increasing the SMD Astrophysics portfolio diversity and resiliency to external budget pressure. The SEP technology employed in this study has strong applicability to SMD Planetary Science community-proposed missions. SEP is a stated flight demonstration priority for NASA's Office of the Chief Technologist (OCT). This new mission architecture for astrophysics Explorers enables an attractive realization of joint goals for OCT and SMD with wide applicability across SMD science disciplines.

  9. Exploring the Digital Universe with Europe's Astrophysical Virtual Observatory

    Science.gov (United States)

    2001-12-01

    N° 73-2001 - Paris, 5 December 2001 The aim of AVO is to give astronomers instant access to the vast databanks now being built up by the world's observatories and forming what is in effect a "digital sky". Using AVO astronomers will be able, for example, to retrieve the elusive traces of the passage of an asteroid as it passes the Earth and so predict its future path and perhaps warn of a possible impact. When a giant star comes to the end of its life in a cataclysmic explosion called a supernova, they will be able to access the digital sky and pinpoint the star shortly before it exploded, adding invaluable data to the study of the evolution of stars. Modern observatories observe the sky continuously and data accumulates remorselessly in the digital archives. The growth rate is impressive and many hundreds of terabytes of data -corresponding to many thousands of billions of pixels - are already available to scientists. The real sky is being digitally reconstructed in the databanks. The volume and complexity of data and information available to astronomers are overwhelming. Hence the problem of how astronomers can possibly manage, distribute and analyse this great wealth of data. The Astrophysical Virtual Observatory will enable them to meet the challenge and "put the Universe online". AVO is a three-year project, funded by the European Commission under its Research and Technological Development (RTD) scheme, to design and implement a virtual observatory for the European astronomical community. The Commission has awarded a contract valued at EUR 4m for the project, starting on 15 November. AVO will provide software tools to enable astronomers to access the multi-wavelength data archives over the Internet and so give them the capability to resolve fundamental questions about the Universe by probing the digital sky. Equivalent searches of the "real" sky would, in comparison, both be prohibitively costly and take far too long. Towards a Global Virtual Observatory The

  10. Introduction to plasma dynamics

    CERN Document Server

    Morozov, A I

    2013-01-01

    As the twenty-first century progresses, plasma technology will play an increasing role in our lives, providing new sources of energy, ion-plasma processing of materials, wave electromagnetic radiation sources, space plasma thrusters, and more. Studies of the plasma state of matter not only accelerate technological developments but also improve the understanding of natural phenomena. Beginning with an introduction to the characteristics and types of plasmas, Introduction to Plasma Dynamics covers the basic models of classical diffuse plasmas used to describe such phenomena as linear and shock w

  11. Exploring the Cosmic Frontier Astrophysical Instruments for the 21st Century

    CERN Document Server

    Lobanov, Andrei P; Cesarsky, Catherine; Diamond, Phillip J

    2007-01-01

    In the coming decades, astrophysical science will benefit enormously from the construction and operation of several major international ground- and space based facilities, such as ALMA, Herschel/Planck, and SKA in the far infrared to radio band, Extremely Large Telescopes, JWST and GAIA in the optical to near infrared regime, XEUS and Constellation-X in the X-ray, and GLAST in the Gamma-ray regime. These and other new instruments will have a major impact in a wide range of scientific topics including the cosmological epoch of reionization, galactic dynamics and nuclear activity, stellar astronomy, extra-solar planets, gamma-ray bursts, X-ray binaries, and many others. On May 18-21, 2004, the Max-Planck-Society’s Harnack-Haus in Dahlem, Berlin hosted the international symposium "Exploring the Cosmic Frontier: Astrophysical Instruments for the 21st Century". The symposium in Berlin was dedicated to exploring the complementarity and synergies between different branches of astrophysical research, by presenting ...

  12. The Relativistic Astrophysics Explorer A New Mission for X-Ray Timing

    CERN Document Server

    Kaaret, P E; Lamb, F K; Morgan, E H; Swank, J H; Zhang, W

    1999-01-01

    The great success of the Rossi X-Ray Timing Explorer (RXTE) has given us a new probe to study strong gravitational fields and to measure the physical properties of black holes and neutron stars. Here, we describe a "next-generation" x-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a "medium-sized" mission. The main instruments will be a narrow-field x-ray detector array with an area of at least ten times that of RXTE, and a wide-field x-ray monitor with good sensitivity and few arcminute position resolution. We describe the design of the instruments and the science which will be possible with a factor of ten increase in collecting area.

  13. Polarization from Relativistic Astrophysical X-ray Sourses: The PRAXyS Small Explorer Observatory

    Science.gov (United States)

    Kallman, Timothy R.; Jahoda, Keith; Kouveliotou, Chryssa; The PRAXyS Team

    2016-04-01

    Polarization is a sensitive probe of geometry near compact objects, but remains largely unexplored in the X-ray band. Polarization is expected from cosmic X-ray sources, yielding insight into the geometry of black hole emission, and the origin and nature of X-ray emission in neutron stars and magnetars. Recent progress with detectors capable of imaging the track of a photoelectron generated by a detection of a cosmic X-ray have made sensitive X-ray polarization observatories possible within the constraints of a NASA Small Explorer mission. We report on the observational capabilities and the scientific goals of the "Polarization from Relativistic Astrophysical X-ray Sources" (PRAXyS) Observatory. PRAXyS is a small explorer which has been selected by NASA for a phase A study.

  14. Exploring nonnormality in magnetohydrodynamic rotating shear flows: application to astrophysical accretion disks

    CERN Document Server

    Bhatia, Tanayveer Singh

    2016-01-01

    The emergence of turbulence in shear flows is a well-investigated field. Yet, one of major issues is the apparent contradiction between linear stability analysis quoting a flow to be stable and results from experiments and simulations proving it to be otherwise. There is some success, in particular in astrophysical systems, based on Magneto-Rotational Instability (MRI). However, MRI requires the system to be weakly magnetized, which is not a feature of general magnetohydrodynamic (MHD) flows. Nevertheless, linear perturbations of such flows are nonnormal in nature which argues for an origin of nonlinearity therein. The idea is, nonnormal perturbations could produce huge transient energy growth (TEG), which may lead to non-linearity and further turbulence. However, so far, nonnormal effects in shear flows have not been explored much in the presence of magnetic fields. Here, we consider the perturbed visco-resistive incompressible MHD shear flows with rotation in general. Basically we consider the magnetized ve...

  15. Explorer for Transient Astrophysics: an X-ray transient mission for the 2020s

    Science.gov (United States)

    Camp, Jordan

    2016-04-01

    Explorer for Transient Astrophysics (ETA) is a wide-field X-ray transient mission proposed for flight starting in 2023. Through its unique imaging X-ray optics that allow a 30 deg by 20 deg FoV in three separate modules, a 1 arc min position resolution and a 10-11 erg/(sec cm2) sensitivity in 2000 sec, ETA will observe numerous events per year of X-ray transients related to compact objects, including: tidal disruptions of stars, supernova shock breakouts, neutron star bursts and superbursts, high redshift Gamma-Ray Bursts, and perhaps most exciting, X-ray counterparts of gravitational wave detections involving stellar mass and possibly supermassive black holes. The mission includes an IR Telescope that allows on-board redshift determination of gamma-ray bursts, and a small gamma-ray burst monitor to be contributed by the Technion (Israel Institute of Technology.)

  16. Astrophysics datamining in the classroom: Exploring real data with new software tools and robotic telescopes

    CERN Document Server

    Doran, Rosa; Boudier, Thomas; Pacôme,; Delva,; Ferlet, Roger; Almeida, Maria L T; Barbosa, Domingos; Gomez, Edward; Pennypacker, Carl; Roche, Paul; Roberts, Sarah

    2012-01-01

    Within the efforts to bring frontline interactive astrophysics and astronomy to the classroom, the Hands on Universe (HOU) developed a set of exercises and platform using real data obtained by some of the most advanced ground and space observatories. The backbone of this endeavour is a new free software Web tool - Such a Lovely Software for Astronomy based on Image J (Salsa J). It is student-friendly and developed specifically for the HOU project and targets middle and high schools. It allows students to display, analyze, and explore professionally obtained astronomical images, while learning concepts on gravitational dynamics, kinematics, nuclear fusion, electromagnetism. The continuous evolving set of exercises and tutorials is being completed with real (professionally obtained) data to download and detailed tutorials. The flexibility of the Salsa J platform tool enables students and teachers to extend the exercises with their own observations. The software developed for the HOU program has been designed to...

  17. Space Explorers: Astronomy Outreach at the Center for Astrophysical Research in Antarctica

    Science.gov (United States)

    Sweitzer, J. S.; Harper, D. A.; Hawkins, L.; Kron, R. G.; Brass, C. O.; Whitt, A. S.

    1993-12-01

    The Center for Astrophysical Research in Antarctica (CARA) is an NSF Science and Technology Center that has been formed to take advantage of the South Pole as an observing site for infrared through millimeter wave astronomy. Besides its research mission, CARA conducts an educational outreach program for Chicago high school and grammar school students. The thirty high school students, called Space Explorers, participate in an intense, multi-year program at three locations: Yerkes Observatory, on the U. of Chicago campus, and at the Adler Planetarium. The Space Explorers program multiplies its efforts through the teaching and mentoring that the high school students do for younger students. Space Explorers reach nearly seventy students in the middle grades by leading astronomy clubs established in the middle schools that feed their high schools. Their largest impact, in terms of total numbers, is the 2,700 grammar school students that the Space Explorers teach yearly with the Adler Planetarium's portable Starlab planetarium. The alliance of three unique organizations within the structure of an NSF STC has made this program possible. The U. of Chicago's Office of Special Programs offers the link to the students, parents and schools. The Adler Planetarium brings to the program unique facilities and expertise in astronomy education. Finally, the scientists, both within CARA and recruited from other University departments, enable the use of the U. of Chicago scientific resources. The Space Explorers program has been translated to a Wisconsin school district and is being studied as a model outreach program by educational institutions in three large cities. It is also serving as an excellent test-bed for exploring electronic learning circles, project based learning and adventure learning. This program is supported by NSF grant DPP-8920223 and NASA contract NAGW-3252.

  18. High Energy Replicated Optics to Explore the Sun Balloon-Borne Telescope: Astrophysical Pointing

    Science.gov (United States)

    Gaskin, Jessica; Wilson-Hodge, Colleen; Ramsey, Brian; Apple, Jeff; Kurt, Dietz; Tennant, Allyn; Swartz, Douglas; Christe, Steven D.; Shih, Albert

    2014-01-01

    On September 21, 2013, the High Energy Replicated Optics to Explore the Sun, or HEROES, balloon-borne x-ray telescope launched from the Columbia Scientific Balloon Facility's site in Ft. Summer, NM. The flight lasted for approximately 27 hours and the observational targets included the Sun and astrophysical sources GRS 1915+105 and the Crab Nebula. Over the past year, the HEROES team upgraded the existing High Energy Replicated Optics (HERO) balloon-borne telescope to make unique scientific measurements of the Sun and astrophysical targets during the same flight. The HEROES Project is a multi-NASA Center effort with team members at both Marshall Space Flight Center (MSFC) and Goddard Space Flight Center (GSFC), and is led by Co-PIs (one at each Center). The HEROES payload consists of the hard X-ray telescope HERO, developed at MSFC, combined with several new systems. To allow the HEROES telescope to make observations of the Sun, a new solar aspect system was added to supplement the existing star camera for fine pointing during both the day and night. A mechanical shutter was added to the star camera to protect it during solar observations and two alignment monitoring systems were added for improved pointing and post-flight data reconstruction. This mission was funded by the NASA HOPE (Hands-On Project Experience) Training Opportunity awarded by the NASA Academy of Program/Project and Engineering Leadership, in partnership with NASA's Science Mission Directorate, Office of the Chief Engineer and Office of the Chief Technologist.

  19. AS12-AS101-3 Breakthrough Capability for the NASA Astrophysics Explorer Program: Reaching the Darkest Sky

    Science.gov (United States)

    Greenhouse, Matthew; Benson, S.; Falck, R.; Fixsen, D.; Gardner, J.; Garvin, J.; Kruk, J.; Oleson, S.; Thronson, H.

    2011-01-01

    We describe a mission architecture designed to substantially increase the science capability of the NASA Science Mission Directorate (SMD) Astrophysics Explorer Program for all AO proposers working within the near-UV to far-infrared spectrum. We have demonstrated that augmentation of Falcon 9 Explorer launch services with a 13 kW Solar Electric Propulsion (SEP) stage can deliver a 700 kg science observatory payload to extra-Zodiacal orbit. Over the above wavelength range, observatory performance is limited by zodiacal light. This new capability enables up to 10X increased photometric sensitivity and 160X increased observing speed relative to a Sun-Earth L2, Earth-trailing, or Earth orbit with no increase in telescope aperture. All enabling SEP stage technologies for this launch service augmentation have reached sufficient readiness (TRl-6) for Explorer Program application in conjunction with the Falcon 9. We demonstrate that enabling Astrophysics Explorers to reach extra-zodiacal orbit will allow this small payload program to rival the Science performance of much larger long development time systems; thuS, providing a means to realize major science objectives while increasing the SMD Astrophysics portfolio diversity and resiliency to external budget pressure. The SEP technology employed in this study has strong applicability to SMD Planetary Science community-proposed missions and is a stated flight demonstration priority for NASA's Office of the Chief Technologist (OCT). This new mission architecture for astrophysics Explorers enables an attractive realization of joint goals for OCT and SMD with wide applicability across SMD science disciplines.

  20. Exploring aspects of scientific publishing in astrophysics and cosmology: the views of scientists

    OpenAIRE

    Polydoratou, P.; Moyle, M

    2008-01-01

    Scientists in astrophysics and cosmology make much use of the arXiv repository. Concerns raised by scientists in those fields about publication costs and delays, and the transparency and validity of the peer review process, raised questions about levels of satisfaction with existing publishing models. This paper discusses the results from a community survey in the fields of astrophysics and cosmology, conducted as part of an investigation into the feasibility of an "overlay journal" model in ...

  1. Solar High-energy Astrophysical Plasmas Explorer (SHAPE). Volume 1: Proposed concept, statement of work and cost plan

    Science.gov (United States)

    Dennis, Brian R.; Martin, Franklin D.; Prince, T.; Lin, R.; Bruner, M.; Culhane, L.; Ramaty, R.; Doschek, G.; Emslie, G.; Lingenfelter, R.

    1986-01-01

    The concept of the Solar High-Energy Astrophysical Plasmas Explorer (SHAPE) is studied. The primary goal is to understand the impulsive release of energy, efficient acceleration of particles to high energies, and rapid transport of energy. Solar flare studies are the centerpieces of the investigation because in flares these high energy processes can be studied in unmatched detail at most wavelenth regions of the electromagnetic spectrum as well as in energetic charged particles and neutrons.

  2. VisIVO: A Library and Integrated Tools for Large Astrophysical Dataset Exploration

    Science.gov (United States)

    Becciani, U.; Costa, A.; Ersotelos, N.; Krokos, M.; Massimino, P.; Petta, C.; Vitello, F.

    2012-09-01

    VisIVO provides an integrated suite of tools and services that can be used in many scientific fields. VisIVO development starts in the Virtual Observatory framework. VisIVO allows users to visualize meaningfully highly-complex, large-scale datasets and create movies of these visualizations based on distributed infrastructures. VisIVO supports high-performance, multi-dimensional visualization of large-scale astrophysical datasets. Users can rapidly obtain meaningful visualizations while preserving full and intuitive control of the relevant parameters. VisIVO consists of VisIVO Desktop - a stand-alone application for interactive visualization on standard PCs, VisIVO Server - a platform for high performance visualization, VisIVO Web - a custom designed web portal, VisIVOSmartphone - an application to exploit the VisIVO Server functionality and the latest VisIVO features: VisIVO Library allows a job running on a computational system (grid, HPC, etc.) to produce movies directly with the code internal data arrays without the need to produce intermediate files. This is particularly important when running on large computational facilities, where the user wants to have a look at the results during the data production phase. For example, in grid computing facilities, images can be produced directly in the grid catalogue while the user code is running in a system that cannot be directly accessed by the user (a worker node). The deployment of VisIVO on the DG and gLite is carried out with the support of EDGI and EGI-Inspire projects. Depending on the structure and size of datasets under consideration, the data exploration process could take several hours of CPU for creating customized views and the production of movies could potentially last several days. For this reason an MPI parallel version of VisIVO could play a fundamental role in increasing performance, e.g. it could be automatically deployed on nodes that are MPI aware. A central concept in our development is thus to

  3. Principles of astrophysics using gravity and stellar physics to explore the cosmos

    CERN Document Server

    Keeton, Charles

    2014-01-01

    This book gives a survey of astrophysics at the advanced undergraduate level.  It originates from a two-semester course sequence at Rutgers University that is meant to appeal not only to astrophysics students but also more broadly to physics and engineering students.  The organization is driven more by physics than by astronomy; in other words, topics are first developed in physics and then applied to astronomical systems that can be investigated, rather than the other way around. The first half of the book focuses on gravity.  Gravity is the dominant force in many astronomical systems, so a tremendous amount can be learned by studying gravity, motion and mass.  The theme in this part of the book, as well as throughout astrophysics, is using motion to investigate mass.  The goal of Chapters 2-11 is to develop a progressively richer understanding of gravity as it applies to objects ranging from planets and moons to galaxies and the universe as a whole. The second half uses other aspects of physics to addr...

  4. Exploring the Use of Virtual Worlds as a Scientific Research Platform: The Meta-Institute for Computational Astrophysics (MICA)

    Science.gov (United States)

    Djorgovski, S. G.; Hut, P.; McMillan, S.; Vesperini, E.; Knop, R.; Farr, W.; Graham, M. J.

    We describe the Meta-Institute for Computational Astrophysics (MICA), the first professional scientific organization based exclusively in virtual worlds (VWs). The goals of MICA are to explore the utility of the emerging VR and VWs technologies for scientific and scholarly work in general, and to facilitate and accelerate their adoption by the scientific research community. MICA itself is an experiment in academic and scientific practices enabled by the immersive VR technologies. We describe the current and planned activities and research directions of MICA, and offer some thoughts as to what the future developments in this arena may be.

  5. Exploring the Use of Virtual Worlds as a Scientific Research Platform: The Meta-Institute for Computational Astrophysics (MICA)

    CERN Document Server

    Djorgovski, S G; McMillan, S; Vesperini, E; Knop, R; Farr, W; Graham, M J

    2009-01-01

    We describe the Meta-Institute for Computational Astrophysics (MICA), the first professional scientific organization based exclusively in virtual worlds (VWs). The goals of MICA are to explore the utility of the emerging VR and VWs technologies for scientific and scholarly work in general, and to facilitate and accelerate their adoption by the scientific research community. MICA itself is an experiment in academic and scientific practices enabled by the immersive VR technologies. We describe the current and planned activities and research directions of MICA, and offer some thoughts as to what the future developments in this arena may be.

  6. Laboratory-Produced X-Ray Photoionized Plasmas for Astrophysics Exploration

    Science.gov (United States)

    Goyon, Clement; Le Pape, Sebastien; Liedahl, Duane; Ma, Tammy; Berzak-Hopkins, Laura; Reverdin, Charles; Rousseaux, Christophe; Renaudin, Patrick; Blancard, Christophe; Nottet, Edouard; Bidault, Niels; Mancini, Roberto; Koenig, Michel

    2015-11-01

    X-ray photoionized plasmas are rare in the laboratory, but of broad importance in astrophysical objects such as active galactic nuclei, x-ray binaries. Indeed, existing models are not yet able to accurately describe these plasmas where ionization is driven by radiation rather than electron collisions. Here, we describe an experiment on the LULI2000 facility whose versatility allows for measuring the X-ray absorption of the plasma while independently probing its electron density and temperature. The bright X-ray source is created by the two main beams focused inside a gold hohlraum and is used to photoionise a Neon gas jet. Then, a thin gold foil serves as a source of backlit photons for absorption spectroscopy. The transmitted spectrum through the plasma is collected by a crystal spectrometer. We will present the experimental setup used to characterize both plasma conditions and X-ray emission. Then we will show the transmitted spectra through the plasma to observe the transition from collision dominated to radiation dominated ionization and compare it to model predictions. This work was performed under the auspices of the U.S.Department of Energy by Lawrence Livermore Natl Lab under Contract No. DE-AC52-07NA27344.

  7. Astrophysics and the exploration of the universe; L'astrophysique et l'exploration de l'Univers

    Energy Technology Data Exchange (ETDEWEB)

    Turck-Chieze, S.; Garcia, R.A.; Brun, A.S.; Minier, V.; Andre, Ph.; Motte, F.; Mathis, St.; Foglizzo, Th.; Decourchelle, A.; Ballet, J.; Chaty, S.; Corbel, St.; Rodriguez, J.; Brahic, A.; Charnoz, S.; Ferrari, C.; Lagage, P.O.; Masset, F.; Pantin, E.; Sauvage, M.; Galliano, F.; Goldwurm, A.; Ballet, J.; Decourchelle, A.; Grenier, I.; Daddi, E.; Elbaz, D.; Bournaud, F.; Yvon, D.; Arnaud, M.; Teyssier, R.; Lehoucq, R.; Palanque-Delabrouille, N.; Lehoucq, R.; Cirelli, M.; Bonvin, C.; Mansoulie, B.; Ruhlmann-Kleider, V.; Refregier, A.; Brax, Ph.; Lavignac, St.; Starck, J.L.; Talvard, M.; Sauvage, M.; Cara, Ch.; Lagage, P.O.; Ferrari, C.; Rodriguez, L.; Sauvageot, J.L.; Lebrun, F.; Grenier, I.; Glicenstein, J.F.; Gerbier, G.

    2009-07-01

    This special issue of Clefs CEA journal is entirely devoted to astrophysics and to the exploration and probing of the Universe. A first part of this dossier, described here, makes a status of our present day knowledge about stars, planets, galaxies, the Universe structure and dark matter. Content: 1 - Stars seed the Universe: What does the Sun tell us?, Probing stellar interiors, From the Sun to the stars, A tour of stellar nurseries, How heavy elements arise, How supernovae explode, Supernova remnants, High-energy objects - sources for astonishment, Focus: A Probing the Universe across the entire light spectrum; 2 - Planets: a dance of small bodies, swirling around up to the finale of their birth: How our world was born, The rings of Saturn: a magnificent research laboratory, Planetary cocoons; 3 - Galaxies: a richly paradoxical evolution: The active life of galaxies, A mysterious black hole, Elucidating the cosmic ray acceleration mechanism, Seeking out the great ancestors, The formation of galaxies: a story of paradoxes, The morphogenesis of galaxies; 4 - The Universe, a homogeneous 'soup' that has turned into a hierarchical structure: The grand thermal history of the Universe, The cosmic web, The formation of the structures of the Universe: the interplay of models, Does the Universe have a shape? Is it finite, or infinite?; 5 - Odyssey across the dark side of the Universe: The puzzle of dark matter, Astrophysics and the observation of dark matter, The theory of dark matter, Could dark matter be generated some day at LHC? A Universe dominated by dark energy, Astrophysics and the observation of dark energy, Theories of dark energy, The matter-antimatter asymmetry of the Universe; 6 - Journey into the lights of the Universe: Microwave - ESA Planck Surveyor, Submillimeter and infrared - ArTeMis, Herschel Space Observatory, VLT-VISIR, Cassini-CIRS, Visible - SoHo-GOLF, X-ray - XMM-Newton, Gamma ray - INTEGRAL, Fermi Gamma-Ray Space Telescope, HESS

  8. Exploring the gas-phase spectroscopy of interstellar PAH and dust analogs: Astrophysical applications

    Science.gov (United States)

    Biennier, Ludovic; Salama, Farid; Allamandola, Lou; Gupta, Manish; O'Keefe, Anthony; Scherer, James J.

    We present and discuss the gas-phase electronic absorption spectra of selected ionized polycyclic aromatic hydrocarbons (PAHs) measured in the UV-Visible-NIR range in an astrophysically relevant environment. This type of measurements provides data on PAHs and nanometer-sized particles that can now be directly compared to astronomical spectra of the UV interstellar (IS) extinction curve and of the diffuse interstellar bands (DIBs). The harsh physical conditions of the IS medium - characterized by a low temperature, an absence of collisions and strong VUV radiation fields - are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. This source combines a pulsed slit supersonic free jet expansion of argon seeded with PAHs (Salama, F., Allamandola, L. J. & Scherer, J. J., `Pulsed discharge nozzle cavity ringdown spectroscopy of cold PAH ions', J. Chem Phys.;in press) that have been pre-selected from Matrix Isolation Spectroscopy (MIS) studies. The absorption spectrum of the Pyrene cation (C16H10+) has also been measured. These experiments provide unique information on the spectra of free, large carbon-containing molecules and ions in the gas phase. The electronic bands measured for this selection of PAH ions are all found to be intrinsically broad (>˜20 cm-1). The laboratory data are compared with recent astronomical spectra of large DIBs. Preliminary results also show that carbon nanoparticles (˜2 nm size) are formed during the short residence time of the precursors in the plasma. This finding holds great potential for the spectroscopy of nanoparticles isolated in the gas-phase in an interstellar-like environment and for understanding the formation process of interstellar grains.

  9. The center for multiscale plasma dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Kevrekidis, Yannis G [Princeton Univ., Princeton, NJ (United States)

    2015-01-20

    This final report describes research performed in Princeton University, led by Professor Yannis G. Kevrekidis, over a period of six years (August 1, 2014 to July 31, 2010, including a one-year, no-cost extension) as part of the Center for Multiscale Plasma Dynamics led by the University of Maryland. The work resulted in the development and implementation of several multiscale algorithms based on the equation-free approach pioneered by the PI, including its applications in plasma dynamics problems. These algoriithms include coarse projective integration and coarse stability/bifurcation computations. In the later stages of the work, new links were made between this multiscale, coarse-graining approach and advances in data mining/machine learning algorithms.

  10. Pulse Power Supply for Plasma Dynamic Accelerator

    Institute of Scientific and Technical Information of China (English)

    YANG Xuanzong; LIU Jian; FENG Chunhua; WANG Long

    2008-01-01

    A new concept of a coaxial plasma dynamic accelerator with a self-energized mag-netic compressor coil to simulate the effects of space debris impact is demonstrated. A brief description is presented about the pulse power supply system including the charging circuit, start switch and current transfer system along with some of the key techniques for this kind of acceler-ator. Using this accelerator configuration, ceramic beads of 100 μm in diameter were accelerated to a speed as high as 18 km/sec. The facility can be used in a laboratory setting to study impact phenomena on solar array materials, potential structural materials for use in space.

  11. Essential astrophysics

    CERN Document Server

    Lang, Kenneth R

    2013-01-01

    Essential Astrophysics is a book to learn or teach from, as well as a fundamental reference volume for anyone interested in astronomy and astrophysics. It presents astrophysics from basic principles without requiring any previous study of astronomy or astrophysics. It serves as a comprehensive introductory text, which takes the student through the field of astrophysics in lecture-sized chapters of basic physical principles applied to the cosmos. This one-semester overview will be enjoyed by undergraduate students with an interest in the physical sciences, such as astronomy, chemistry, engineering or physics, as well as by any curious student interested in learning about our celestial science. The mathematics required for understanding the text is on the level of simple algebra, for that is all that is needed to describe the fundamental principles. The text is of sufficient breadth and depth to prepare the interested student for more advanced specialized courses in the future. Astronomical examples are provide...

  12. Neutrino Astrophysics

    CERN Document Server

    Volpe, Cristina

    2016-01-01

    We summarize the progress in neutrino astrophysics and emphasize open issues in our understanding of neutrino flavor conversion in media. We discuss solar neutrinos, core-collapse supernova neutrinos and conclude with ultra-high energy neutrinos.

  13. Nuclear astrophysics

    CERN Document Server

    Arnould, M

    1999-01-01

    Nuclear astrophysics is that branch of astrophysics which helps understanding some of the many facets of the Universe through the knowledge of the microcosm of the atomic nucleus. In the last decades much advance has been made in nuclear astrophysics thanks to the sometimes spectacular progress in the modelling of the structure and evolution of the stars, in the quality and diversity of the astronomical observations, as well as in the experimental and theoretical understanding of the atomic nucleus and of its spontaneous or induced transformations. Developments in other sub-fields of physics and chemistry have also contributed to that advance. Many long-standing problems remain to be solved, however, and the theoretical understanding of a large variety of observational facts needs to be put on safer grounds. In addition, new questions are continuously emerging, and new facts endanger old ideas. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experime...

  14. Nuclear astrophysics

    International Nuclear Information System (INIS)

    The problem of core-collapse supernovae is used to illustrate the many connections between nuclear astrophysics and the problems nuclear physicists study in terrestrial laboratories. Efforts to better understand the collapse and mantle ejection are also motivated by a variety of interdisciplinary issues in nuclear, particle, and astrophysics, including galactic chemical evolution, neutrino masses and mixing, and stellar cooling by the emission of new particles. The current status of theory and observations is summarized

  15. Relativistic astrophysics

    CERN Document Server

    Demianski, Marek

    2013-01-01

    Relativistic Astrophysics brings together important astronomical discoveries and the significant achievements, as well as the difficulties in the field of relativistic astrophysics. This book is divided into 10 chapters that tackle some aspects of the field, including the gravitational field, stellar equilibrium, black holes, and cosmology. The opening chapters introduce the theories to delineate gravitational field and the elements of relativistic thermodynamics and hydrodynamics. The succeeding chapters deal with the gravitational fields in matter; stellar equilibrium and general relativity

  16. Astrophysical Concepts

    CERN Document Server

    Harwit, Martin

    2006-01-01

    This classic text, aimed at senior undergraduates and beginning graduate students in physics and astronomy, presents a wide range of astrophysical concepts in sufficient depth to give the reader a quantitative understanding of the subject. Emphasizing physical concepts, the book outlines cosmic events but does not portray them in detail: it provides a series of astrophysical sketches. For this fourth edition, nearly every part of the text has been reconsidered and rewritten, new sections have been added to cover recent developments, and others have been extensively revised and brought up to date. The book begins with an outline of the scope of modern astrophysics and enumerates some of the outstanding problems faced in the field today. The basic physics needed to tackle these questions are developed in the next few chapters using specific astronomical processes as examples. The second half of the book enlarges on these topics and shows how we can obtain quantitative insight into the structure and evolution of...

  17. Nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Bruxelles (Belgium); Takahashi, K. [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

    1999-03-01

    Nuclear astrophysics is that branch of astrophysics which helps understanding of the Universe, or at least some of its many faces, through the knowledge of the microcosm of the atomic nucleus. It attempts to find as many nuclear physics imprints as possible in the macrocosm, and to decipher what those messages are telling us about the varied constituent objects in the Universe at present and in the past. In the last decades much advance has been made in nuclear astrophysics thanks to the sometimes spectacular progress made in the modelling of the structure and evolution of the stars, in the quality and diversity of the astronomical observations, as well as in the experimental and theoretical understanding of the atomic nucleus and of its spontaneous or induced transformations. Developments in other subfields of physics and chemistry have also contributed to that advance. Notwithstanding the accomplishment, many long-standing problems remain to be solved, and the theoretical understanding of a large variety of observational facts needs to be put on safer grounds. In addition, new questions are continuously emerging, and new facts endangering old ideas. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experimental and theoretical components. On top of the fact that large varieties of nuclei have to be dealt with, these nuclei are immersed in highly unusual environments which may have a significant impact on their static properties, the diversity of their transmutation modes, and on the probabilities of these modes. In order to have a chance of solving some of the problems nuclear astrophysics is facing, the astrophysicists and nuclear physicists are obviously bound to put their competence in common, and have sometimes to benefit from the help of other fields of physics, like particle physics, plasma physics or solid-state physics. Given the highly varied and complex aspects, we pick here some specific nuclear

  18. Nuclear astrophysics

    Science.gov (United States)

    Arnould, M.; Takahashi, K.

    1999-03-01

    Nuclear astrophysics is that branch of astrophysics which helps understanding of the Universe, or at least some of its many faces, through the knowledge of the microcosm of the atomic nucleus. It attempts to find as many nuclear physics imprints as possible in the macrocosm, and to decipher what those messages are telling us about the varied constituent objects in the Universe at present and in the past. In the last decades much advance has been made in nuclear astrophysics thanks to the sometimes spectacular progress made in the modelling of the structure and evolution of the stars, in the quality and diversity of the astronomical observations, as well as in the experimental and theoretical understanding of the atomic nucleus and of its spontaneous or induced transformations. Developments in other subfields of physics and chemistry have also contributed to that advance. Notwithstanding the accomplishment, many long-standing problems remain to be solved, and the theoretical understanding of a large variety of observational facts needs to be put on safer grounds. In addition, new questions are continuously emerging, and new facts endangering old ideas. This review shows that astrophysics has been, and still is, highly demanding to nuclear physics in both its experimental and theoretical components. On top of the fact that large varieties of nuclei have to be dealt with, these nuclei are immersed in highly unusual environments which may have a significant impact on their static properties, the diversity of their transmutation modes, and on the probabilities of these modes. In order to have a chance of solving some of the problems nuclear astrophysics is facing, the astrophysicists and nuclear physicists are obviously bound to put their competence in common, and have sometimes to benefit from the help of other fields of physics, like particle physics, plasma physics or solid-state physics. Given the highly varied and complex aspects, we pick here some specific nuclear

  19. Neutrino astrophysics

    International Nuclear Information System (INIS)

    A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric and solar neutrinos. The major role that neutrinos play in astrophysics and cosmology is illustrated. (author)

  20. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  1. Augmented Reality in Astrophysics

    CERN Document Server

    Vogt, Frédéric P A

    2013-01-01

    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented Articles. We demonstrate that the emerging technology of Augmented Reality can already be used and implemented without expert knowledge using currently available apps. Our experiments highlight the potential of Augmented Reality to improve the communication of scientific results in the field of astrophysics. We also present feedback gathered from the Australian astrophysics community that reveals evidence of some interest in this technology by astronomers who experimented with Augmented Posters. In addition, we discuss p...

  2. Nuclear Astrophysics

    Science.gov (United States)

    Drago, Alessandro

    2005-04-01

    The activity of the Italian nuclear physicists community in the field of Nuclear Astrophysics is reported. The researches here described have been performed within the project "Fisica teorica del nucleo e dei sistemi a multi corpi", supported by the Ministero dell'Istruzione, dell'Università e della Ricerca.

  3. Observational astrophysics

    CERN Document Server

    Smith, Robert C

    1995-01-01

    Combining a critical account of observational methods (telescopes and instrumentation) with a lucid description of the Universe, including stars, galaxies and cosmology, Smith provides a comprehensive introduction to the whole of modern astrophysics beyond the solar system. The first half describes the techniques used by astronomers to observe the Universe: optical telescopes and instruments are discussed in detail, but observations at all wavelengths are covered, from radio to gamma-rays. After a short interlude describing the appearance of the sky at all wavelengths, the role of positional astronomy is highlighted. In the second half, a clear description is given of the contents of the Universe, including accounts of stellar evolution and cosmological models. Fully illustrated throughout, with exercises given in each chapter, this textbook provides a thorough introduction to astrophysics for all physics undergraduates, and a valuable background for physics graduates turning to research in astronomy.

  4. astrophysical significance

    Directory of Open Access Journals (Sweden)

    Dartois E.

    2014-02-01

    Full Text Available Clathrate hydrates, ice inclusion compounds, are of major importance for the Earth’s permafrost regions and may control the stability of gases in many astrophysical bodies such as the planets, comets and possibly interstellar grains. Their physical behavior may provide a trapping mechanism to modify the absolute and relative composition of icy bodies that could be the source of late-time injection of gaseous species in planetary atmospheres or hot cores. In this study, we provide and discuss laboratory-recorded infrared signatures of clathrate hydrates in the near to mid-infrared and the implications for space-based astrophysical tele-detection in order to constrain their possible presence.

  5. Neutrino Astrophysics

    OpenAIRE

    Haxton, W. C.

    2000-01-01

    A general overview of neutrino physics and astrophysics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and introduce the main scenarios to provide them a mass. The present bounds and the positive indications in favor of non-zero neutrino masses are discussed, including the recent results on atmospheric an...

  6. Augmented Reality in Astrophysics

    OpenAIRE

    Vogt, Frédéric P. A.; Shingles, Luke J.

    2013-01-01

    Augmented Reality consists of merging live images with virtual layers of information. The rapid growth in the popularity of smartphones and tablets over recent years has provided a large base of potential users of Augmented Reality technology, and virtual layers of information can now be attached to a wide variety of physical objects. In this article, we explore the potential of Augmented Reality for astrophysical research with two distinct experiments: (1) Augmented Posters and (2) Augmented...

  7. ASTRO-1: a 1.8m unobscured space observatory for next generation UV/visible astrophysics and exoplanet exploration

    Science.gov (United States)

    Matthews, Gary W.; Egerman, Robert; Morse, Jon A.; Wilkes, Belinda

    2016-07-01

    The Hubble Space Telescope has been a scientific marvel that has provided unimaginable imagery and scientific discovery. Its exquisite UV/Visible imaging performance is unmatched from the ground. In NASA's future planning, the earliest possible successor mission would be in the 3030s, well beyond the expected lifetime of Hubble. The ASTRO-1 space telescope is a 1.8m off-axis (unobscured) observatory that looks to fill this critical void with Hubble-like performance to continue the scientific quest while also providing the possibility for exoplanet research with a coronagraphic instrument and/or a free flying starshade. BoldlyGo Institute seeks to reach beyond NASA funding to leverage the high public interest in space research and exploration, and the search for life beyond Earth.

  8. Neutrinos in astrophysics and cosmology

    Science.gov (United States)

    Balantekin, A. B.

    2016-06-01

    Neutrinos play a crucial role in many aspects of astrophysics and cosmology. Since they control the electron fraction, or equivalently neutron-to-proton ratio, neutrino properties impact yields of r-process nucleosynthesis. Similarly the weak decoupling temperature in the Big Bang Nucleosynthesis epoch is exponentially dependent on the neutron-to-proton ratio. In these conference proceedings, I briefly summarize some of the recent work exploring the role of neutrinos in astrophysics and cosmology.

  9. Neutrinos in Astrophysics and Cosmology

    CERN Document Server

    Balantekin, A B

    2016-01-01

    Neutrinos play a crucial role in many aspects of astrophysics and cosmology. Since they control the electron fraction, or equivalently neutron-to-proton ratio, neutrino properties impact yields of r-process nucleosynthesis. Similarly the weak decoupling temperature in the Big Bang Nucleosynthesis epoch is exponentially dependent on the neutron-to-proton ratio. In these conference proceedings, I briefly summarize some of the recent work exploring the role of neutrinos in astrophysics and cosmology.

  10. Astrophysical cosmology

    Science.gov (United States)

    Bardeen, J. M.

    The last several years have seen a tremendous ferment of activity in astrophysical cosmology. Much of the theoretical impetus has come from particle physics theories of the early universe and candidates for dark matter, but what promise to be even more significant are improved direct observations of high z galaxies and intergalactic matter, deeper and more comprehensive redshift surveys, and the increasing power of computer simulations of the dynamical evolution of large scale structure. Upper limits on the anisotropy of the microwave background radiation are gradually getting tighter and constraining more severely theoretical scenarios for the evolution of the universe.

  11. Nonperturbative Quantum Field Theory in Astrophysics

    OpenAIRE

    Mazur, Dan

    2012-01-01

    The extreme electromagnetic or gravitational fields associated with some astrophysical objects can give rise to macroscopic effects arising from the physics of the quantum vacuum. Therefore, these objects are incredible laboratories for exploring the physics of quantum field theories. In this dissertation, we explore this idea in three astrophysical scenarios.

  12. Computational Astrophysics

    Science.gov (United States)

    Mickaelian, A. M.; Astsatryan, H. V.

    2015-07-01

    Present astronomical archives that contain billions of objects, both Galactic and extragalactic, and the vast amount of data on them allow new studies and discoveries. Astrophysical Virtual Observatories (VO) use available databases and current observing material as a collection of interoperating data archives and software tools to form a research environment in which complex research programs can be conducted. Most of the modern databases give at present VO access to the stored information, which makes possible also a fast analysis and managing of these data. Cross-correlations result in revealing new objects and new samples. Very often dozens of thousands of sources hide a few very interesting ones that are needed to be discovered by comparison of various physical characteristics. VO is a prototype of Grid technologies that allows distributed data computation, analysis and imaging. Particularly important are data reduction and analysis systems: spectral analysis, SED building and fitting, modelling, variability studies, cross correlations, etc. Computational astrophysics has become an indissoluble part of astronomy and most of modern research is being done by means of it.

  13. Collisional cross sections and momentum distributions in astrophysical plasmas: dynamics and statistical mechanics link

    OpenAIRE

    Ferro, Fabrizio; Quarati, Piero

    2004-01-01

    We show that, in stellar core plasmas, the one-body momentum distribution function is strongly dependent, at least in the high velocity regime, on the microscopic dynamics of ion elastic collisions and therefore on the effective collisional cross sections, if a random force field is present. We take into account two cross sections describing ion-dipole and ion-ion screened interactions. Furthermore we introduce a third unusual cross section, to link statistical distributions and a quantum eff...

  14. Astrophysical fluid dynamics

    Science.gov (United States)

    Ogilvie, Gordon I.

    2016-06-01

    > These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation and internal dynamics of stars and giant planets, the workings of jets and accretion discs around stars and black holes and the dynamics of the expanding Universe. Effects that can be important in astrophysical fluids include compressibility, self-gravitation and the dynamical influence of the magnetic field that is `frozen in' to a highly conducting plasma. The basic models introduced and applied in this course are Newtonian gas dynamics and magnetohydrodynamics (MHD) for an ideal compressible fluid. The mathematical structure of the governing equations and the associated conservation laws are explored in some detail because of their importance for both analytical and numerical methods of solution, as well as for physical interpretation. Linear and nonlinear waves, including shocks and other discontinuities, are discussed. The spherical blast wave resulting from a supernova, and involving a strong shock, is a classic problem that can be solved analytically. Steady solutions with spherical or axial symmetry reveal the physics of winds and jets from stars and discs. The linearized equations determine the oscillation modes of astrophysical bodies, as well as their stability and their response to tidal forcing.

  15. Trends in Nuclear Astrophysics

    CERN Document Server

    Schatz, Hendrik

    2016-01-01

    Nuclear Astrophysics is a vibrant field at the intersection of nuclear physics and astrophysics that encompasses research in nuclear physics, astrophysics, astronomy, and computational science. This paper is not a review. It is intended to provide an incomplete personal perspective on current trends in nuclear astrophysics and the specific role of nuclear physics in this field.

  16. Two LANL laboratory astrophysics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Intrator, Thomas P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-24

    Two laboratory experiments are described that have been built at Los Alamos (LANL) to gain access to a wide range of fundamental plasma physics issues germane to astro, space, and fusion plasmas. The overarching theme is magnetized plasma dynamics which includes significant currents, MHD forces and instabilities, magnetic field creation and annihilation, sheared flows and shocks. The Relaxation Scaling Experiment (RSX) creates current sheets and flux ropes that exhibit fully 3D dynamics, and can kink, bounce, merge and reconnect, shred, and reform in complicated ways. Recent movies from a large data set describe the 3D magnetic structure of a driven and dissipative single flux rope that spontaneously self-saturates a kink instability. Examples of a coherent shear flow dynamo driven by colliding flux ropes will also be shown. The Magnetized Shock Experiment (MSX) uses Field reversed configuration (FRC) experimental hardware that forms and ejects FRCs at 150km/sec. This is sufficient to drive a collision less magnetized shock when stagnated into a mirror stopping field region with Alfven Mach number MA=3 so that super critical shocks can be studied. We are building a plasmoid accelerator to drive Mach numbers MA >> 3 to access solar wind and more exotic astrophysical regimes. Unique features of this experiment include access to parallel, oblique and perpendicular shocks, shock region much larger than ion gyro radii and ion inertial length, room for turbulence, and large magnetic and fluid Reynolds numbers.

  17. Nuclear Astrophysics: CIPANP 2006

    OpenAIRE

    Haxton, W. C.

    2006-01-01

    I review progress that has been made in nuclear astrophysics over the past few years and summarize some of the questions that remain. Topics selected include solar neutrinos, supernovae (the explosion and associated nucleosynthesis), laboratory astrophysics, and neutron star structure.

  18. Plasma dynamics of a laser filamentation-guided spark

    CERN Document Server

    Point, Guillaume; Carbonnel, Jérôme; Mysyrowicz, André; Houard, Aurélien

    2016-01-01

    We investigate experimentally the plasma dynamics of a centimeter-scale, laser filamentation-guided spark discharge. Using electrical and optical diagnostics to study monopolar discharges with varying current pulses we show that plasma decay is dominated by free electron recombination if the current decay time is shorter than the recombination characteristic time. In the opposite case, the plasma electron density closely follows the current evolution. We demonstrate that this criterion holds true in the case of damped AC sparks, and that alternative current is the best option to achieve a long plasma lifetime for a given peak current.

  19. Exploring the Capabilities of the Anti-Coincidence Shield of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) Spectrometer to Study Solar Flares

    Science.gov (United States)

    Rodríguez-Gasén, R.; Kiener, J.; Tatischeff, V.; Vilmer, N.; Hamadache, C.; Klein, K.-L.

    2014-05-01

    The International Gamma-Ray Astrophysics Laboratory (INTEGRAL) is a European Space Agency hard X-ray/ γ-ray observatory for astrophysics, covering photon energies from 15 keV to 10 MeV. It was launched in 2002, and since then the Bismuth Germanate (BGO) detectors of the Anti-Coincidence Shield (ACS) of the Spectrometer on INTEGRAL (SPI) have detected many hard X-ray (HXR) bursts from the Sun, producing light curves at photon energies above ≈ 100 keV. The spacecraft has a highly elliptical orbit, providing long uninterrupted observing (about 90 % of the orbital period) with nearly constant background due to the shorter time needed to cross Earth's radiation belts. However, because of technical constraints, INTEGRAL cannot be pointed at the Sun, and high-energy solar photons are always detected in nonstandard observation conditions. To make the data useable for solar studies, we have undertaken a major effort to specify the observing conditions through Monte Carlo simulations of the response of ACS for several selected flares. We checked the performance of the model employed for the Monte Carlo simulations using the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations for the same sample of solar flares. We conclude that although INTEGRAL was not designed to perform solar observations, ACS is a useful instrument for solar-flare research. In particular, its relatively large effective area allows determining good-quality HXR/ γ-ray light curves for X- and M-class solar flares and, in some cases, probably also for C-class flares.

  20. Astrophysical Hydrodynamics An Introduction

    CERN Document Server

    Shore, Steven N

    2007-01-01

    This latest edition of the proven and comprehensive treatment on the topic -- from the bestselling author of ""Tapestry of Modern Astrophysics"" -- has been updated and revised to reflect the newest research results. Suitable for AS0000 and AS0200 courses, as well as advanced astrophysics and astronomy lectures, this is an indispensable theoretical backup for studies on celestial body formation and astrophysics. Includes exercises with solutions.

  1. Astrophysics and Space Science

    Science.gov (United States)

    Mould, Jeremy; Brinks, Elias; Khanna, Ramon

    2015-08-01

    Astrophysics and Space Science publishes original contributions and invited reviews covering the entire range of astronomy, astrophysics, astrophysical cosmology, planetary and space science, and the astrophysical aspects of astrobiology. This includes both observational and theoretical research, the techniques of astronomical instrumentation and data analysis, and astronomical space instrumentation. We particularly welcome papers in the general fields of high-energy astrophysics, astrophysical and astrochemical studies of the interstellar medium including star formation, planetary astrophysics, the formation and evolution of galaxies and the evolution of large scale structure in the Universe. Papers in mathematical physics or in general relativity which do not establish clear astrophysical applications will not longer be considered.The journal also publishes topical collections consisting of invited reviews and original research papers selected special issues in research fields of particular scientific interest. These consist of both invited reviews and original research papers.Conference proceedings will not be considered. All papers published in the journal are subject to thorough and strict peer-reviewing.Astrophysics and Space Science has an Impact Factor of 2.4 and features short editorial turnaround times as well as short publication times after acceptance, and colour printing free of charge. Published by Springer the journal has a very wide online dissemination and can be accessed by researchers at a very large number of institutes worldwide.

  2. Lecture notes: Astrophysical fluid dynamics

    CERN Document Server

    Ogilvie, Gordon I

    2016-01-01

    These lecture notes and example problems are based on a course given at the University of Cambridge in Part III of the Mathematical Tripos. Fluid dynamics is involved in a very wide range of astrophysical phenomena, such as the formation and internal dynamics of stars and giant planets, the workings of jets and accretion discs around stars and black holes, and the dynamics of the expanding Universe. Effects that can be important in astrophysical fluids include compressibility, self-gravitation and the dynamical influence of the magnetic field that is 'frozen in' to a highly conducting plasma. The basic models introduced and applied in this course are Newtonian gas dynamics and magnetohydrodynamics (MHD) for an ideal compressible fluid. The mathematical structure of the governing equations and the associated conservation laws are explored in some detail because of their importance for both analytical and numerical methods of solution, as well as for physical interpretation. Linear and nonlinear waves, includin...

  3. Astrophysical Quark Matter

    OpenAIRE

    Xu, R. X.

    2004-01-01

    The quark matter may have great implications in astrophysical studies, which could appear in the early Universe, in compact stars, and/or as cosmic rays. After a general review of astrophysical quark matter, the density-dominated quark matter is focused.

  4. Relativistic Astrophysics; Astrofisica Relativista

    Energy Technology Data Exchange (ETDEWEB)

    Font, J. A.

    2015-07-01

    The relativistic astrophysics is the field of astrophysics employing the theory of relativity Einstein as physical-mathematical model is to study the universe. This discipline analyzes astronomical contexts in which the laws of classical mechanics of Newton's law of gravitation are not valid. (Author)

  5. Astrophysics in a nutshell

    CERN Document Server

    Maoz, Dan

    2007-01-01

    A concise but thorough introduction to the observational data and theoretical concepts underlying modern astronomy, Astrophysics in a Nutshell is designed for advanced undergraduate science majors taking a one-semester course. This well-balanced and up-to-date textbook covers the essentials of modern astrophysics--from stars to cosmology--emphasizing the common, familiar physical principles that govern astronomical phenomena, and the interplay between theory and observation. In addition to traditional topics such as stellar remnants, galaxies, and the interstellar medium, Astrophysics in a N

  6. An invitation to astrophysics

    CERN Document Server

    Padmanabhan, Thanu

    2006-01-01

    This unique book provides a clear and lucid description of several aspects of astrophysics and cosmology in a language understandable to a physicist or beginner in astrophysics. It presents the key topics in all branches of astrophysics and cosmology in a simple and concise language. The emphasis is on currently active research areas and exciting new frontiers rather than on more pedantic topics. Many complicated results are introduced with simple, novel derivations which strengthen the conceptual understanding of the subject. The book also contains over one hundred exercises which will help s

  7. Gas Effect On Plasma Dynamics Of Laser Ablation Zinc Oxide

    Science.gov (United States)

    Abdelli-Messaci, S.; Kerdja, T.; Lafane, S.; Malek, S.

    2008-09-01

    In order to synthesis zinc oxide thin films and nanostructures, laser ablation of ZnO target into both vacuum and oxygen atmosphere was performed. The gas effect on the plume dynamics was studied for O2 pressures varied between 10-2 to 70 mbar. Plasma plume evolution was investigated by ICCD camera fast imaging. The plasma was created by a KrF excimer laser (λ = 248 nm, τ = 25 ns) at a fluence of 2 J/cm2. The light emitted by the plume was observed along the perpendicular to the ejection direction through a fast intensified charge-coupled device (ICCD). We have found that the plasma dynamics is very affected by the gas pressures. The photographs reveal the stratification of plasma into slow and fast components for 0.5 mbar O2 pressures and beyond. The photographs also show the apparition of hydrodynamic instabilities which are related to chemical reactions between the plasma and the surrounding gas for a certain range of pressures.

  8. Neutrino physics and astrophysics

    International Nuclear Information System (INIS)

    The plenary reports of Neutrino '80 are presented by experts in neutrino physics and astrophysics. Their International Conference on Neutrino Physics and Astrophysics was held in Erice (Italy), June 23 through 28, 1980. The proceedings include reviews of part research, the history of neutrino research and coverage of recent results and theoretical speculations. Topics include high- and low-energy neutrino astrophysics, weak charged and neutral currents, low and intermediate weak interactions, neutrino oscillations, and parity violation in atoms and nuclei conservation laws. Weak interactions in lepton-lepton and lepton-nucleon collisions, beam dump experiments, new theoretical ideas, and future developments in accelerators and detectors are also included. The topics are introduced by a historical perspective section and then grouped under the headings of neutrino astrophysics, weak charged currents, weak neutral currents, low and intermediate energy interactions, conservation laws, weak interactions in electron and hadron experiments, and a final section on future accelerator, new neutrino detection technology and concluding remarks

  9. Topics in Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Some topics in nuclear astrophysics are discussed, e.g.: highly evolved stellar cores, stellar evolution (through the temperature analysis of stellar surface), nucleosynthesis and finally the solar neutrino problem. (L.C.)

  10. Astrophysics Decoding the cosmos

    CERN Document Server

    Irwin, Judith A

    2007-01-01

    Astrophysics: Decoding the Cosmos is an accessible introduction to the key principles and theories underlying astrophysics. This text takes a close look at the radiation and particles that we receive from astronomical objects, providing a thorough understanding of what this tells us, drawing the information together using examples to illustrate the process of astrophysics. Chapters dedicated to objects showing complex processes are written in an accessible manner and pull relevant background information together to put the subject firmly into context. The intention of the author is that the book will be a 'tool chest' for undergraduate astronomers wanting to know the how of astrophysics. Students will gain a thorough grasp of the key principles, ensuring that this often-difficult subject becomes more accessible.

  11. Accelerator Experiments for Astrophysics

    OpenAIRE

    Ng, Johnny S. T.

    2003-01-01

    Many recent discoveries in astrophysics involve phenomena that are highly complex. Carefully designed experiments, together with sophisticated computer simulations, are required to gain insights into the underlying physics. We show that particle accelerators are unique tools in this area of research, by providing precision calibration data and by creating extreme experimental conditions relevant for astrophysics. In this paper we discuss laboratory experiments that can be carried out at the S...

  12. Theoretical physics and astrophysics

    CERN Document Server

    Ginzburg, VL

    1979-01-01

    The aim of this book is to present, on the one hand various topics in theoretical physics in depth - especially topics related to electrodynamics - and on the other hand to show how these topics find applications in various aspects of astrophysics. The first text on theoretical physics and astrophysical applications, it covers many recent advances including those in X-ray, &ggr;-ray and radio-astronomy, with comprehensive coverage of the literature

  13. Laboratory Astrophysics White Paper

    Science.gov (United States)

    Brickhouse, Nancy; Federman, Steve; Kwong, Victor; Salama, Farid; Savin, Daniel; Stancil, Phillip; Weingartner, Joe; Ziurys, Lucy

    2006-01-01

    Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomical and planetary research and will remain so for many generations to come. From the level of scientific conception to that of the scientific return, it is our understanding of the underlying processes that allows us to address fundamental questions regarding the origins and evolution of galaxies, stars, planetary systems, and life in the cosmos. In this regard, laboratory astrophysics is much like detector and instrument development at NASA and NSF; these efforts are necessary for the astronomical research being funded by the agencies. The NASA Laboratory Astrophysics Workshop met at the University of Nevada, Las Vegas (UNLV) from 14-16 February, 2006 to identify the current laboratory data needed to support existing and future NASA missions and programs in the Astrophysics Division of the Science Mission Directorate (SMD). Here we refer to both laboratory and theoretical work as laboratory astrophysics unless a distinction is necessary. The format for the Workshop involved invited talks by users of laboratory data, shorter contributed talks and poster presentations by both users and providers that highlighted exciting developments in laboratory astrophysics, and breakout sessions where users and providers discussed each others' needs and limitations. We also note that the members of the Scientific Organizing Committee are users as well as providers of laboratory data. As in previous workshops, the focus was on atomic, molecular, and solid state physics.

  14. University of Maryland component of the Center for Multiscale Plasma Dynamics: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Dorland, William [University of Maryland

    2014-11-18

    The Center for Multiscale Plasma Dynamics (CMPD) was a five-year Fusion Science Center. The University of Maryland (UMD) and UCLA were the host universities. This final technical report describes the physics results from the UMD CMPD.

  15. Magnetic processes in astrophysics theory, simulations, experiments

    CERN Document Server

    Rüdiger, Günther; Hollerbach, Rainer

    2013-01-01

    In this work the authors draw upon their expertise in geophysical and astrophysical MHD to explore the motion of electrically conducting fluids, the so-called dynamo effect, and describe the similarities and differences between different magnetized objects. They also explain why magnetic fields are crucial to the formation of the stars, and discuss promising experiments currently being designed to investigate some of the relevant physics in the laboratory. This interdisciplinary approach will appeal to a wide audience in physics, astrophysics and geophysics. This second edition covers such add

  16. Observations of Magnetic Reconnection and Plasma Dynamics in Mercury's Magnetosphere

    Science.gov (United States)

    DiBraccio, Gina A.

    Mercury's magnetosphere is formed as a result of the supersonic solar wind interacting with the planet's intrinsic magnetic field. The combination of the weak planetary dipole moment and intense solar wind forcing of the inner heliosphere creates a unique space environment, which can teach us about planetary magnetospheres. In this work, we analyze the first in situ orbital observations at Mercury, provided by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Magnetic reconnection and the transport of plasma and magnetic flux are investigated using MESSENGER Magnetometer and Fast Imaging Plasma Spectrometer measurements. Here, we report our results on the effect of magnetic reconnection and plasma dynamics on Mercury's space environment: (1) Mercury's magnetosphere is driven by frequent, intense magnetic reconnection observed in the form of magnetic field components normal to the magnetopause, BN, and as helical bundles of flux, called magnetic flux ropes, in the cross-tail current sheet. The high reconnection rates are determined to be a direct consequence of the low plasma beta, the ratio of plasma to magnetic pressure, in the inner heliosphere. (2) As upstream solar wind conditions vary, we find that reconnection occurs at Mercury's magnetopause for all orientations of the interplanetary magnetic field, independent of shear angle. During the most extreme solar wind forcing events, the influence of induction fields generated within Mercury's highly conducting core are negated by erosion due to persistent magnetopause reconnection. (3) We present the first observations of Mercury's plasma mantle, which forms as a result of magnetopause reconnection and allows solar wind plasma to enter into the high-latitude magnetotail through the dayside cusps. The energy dispersion observed in the plasma mantle protons is used to infer the cross-magnetosphere electric field, providing a direct measurement of solar wind momentum

  17. Astrophysics Source Code Library

    CERN Document Server

    Allen, Alice; Berriman, Bruce; Hanisch, Robert J; Mink, Jessica; Teuben, Peter J

    2012-01-01

    The Astrophysics Source Code Library (ASCL), founded in 1999, is a free on-line registry for source codes of interest to astronomers and astrophysicists. The library is housed on the discussion forum for Astronomy Picture of the Day (APOD) and can be accessed at http://ascl.net. The ASCL has a comprehensive listing that covers a significant number of the astrophysics source codes used to generate results published in or submitted to refereed journals and continues to grow. The ASCL currently has entries for over 500 codes; its records are citable and are indexed by ADS. The editors of the ASCL and members of its Advisory Committee were on hand at a demonstration table in the ADASS poster room to present the ASCL, accept code submissions, show how the ASCL is starting to be used by the astrophysics community, and take questions on and suggestions for improving the resource.

  18. Surprises in astrophysical gasdynamics

    CERN Document Server

    Balbus, Steven A

    2016-01-01

    Much of astrophysics consists of the study of ionised gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetised fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one's a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosynchratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out import...

  19. Nuclear reactions in astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M.; Rayet, M. (Universite Libre de Bruxelles (BE))

    1990-06-01

    At all times and at all astrophysical scales, nuclear reactions have played and continue to play a key role. This concerns the energetics as well as the production of nuclides (nucleosynthesis). After a brief review of the observed composition of various objects in the universe, and especially of the solar system, the basic ingredients that are required in order to build up models for the chemical evolution of galaxies are sketched. Special attention is paid to the evaluation of the stellar yields through an overview of the important burning episodes and nucleosynthetic processes that can develop in non-exploding or exploding stars. Emphasis is put on the remaining astrophysical and nuclear physics uncertainties that hamper a clear understanding of the observed characteristics, and especially compositions, of a large variety of astrophysical objects.

  20. Challenges of Relativistic Astrophysics

    CERN Document Server

    Opher, Reuven

    2013-01-01

    I discuss some of the most outstanding challenges in relativistic astrophysics in the subjects of: compact objects (Black Holes and Neutron Stars); dark sector (Dark Matter and Dark Energy); plasma astrophysics (Origin of Jets, Cosmic Rays and Magnetic Fields) and the primordial universe (Physics at the beginning of the Universe). In these four subjects, I discuss twelve of the most important challenges. These challenges give us insight into new physics that can only be studied in the large scale Universe. The near future possibilities, in observations and theory, for addressing these challenges, are also discussed.

  1. Introduction to Nuclear Astrophysics

    International Nuclear Information System (INIS)

    In the first lecture of this volume, we will present the basic fundamental ideas regarding nuclear processes occurring in stars. We start from stellar observations, will then elaborate on some important quantum-mechanical phenomena governing nuclear reactions, continue with how nuclear reactions proceed in a hot stellar plasma and, finally, we will provide an overview of stellar burning stages. At the end, the current knowledge regarding the origin of the elements is briefly summarized. This lecture is directed towards the student of nuclear astrophysics. Our intention is to present seemingly unrelated phenomena of nuclear physics and astrophysics in a coherent framework.

  2. Theoretical astrophysics an introduction

    CERN Document Server

    Bartelmann, Matthias

    2013-01-01

    A concise yet comprehensive introduction to the central theoretical concepts of modern astrophysics, presenting hydrodynamics, radiation, and stellar dynamics all in one textbook. Adopting a modular structure, the author illustrates a small number of fundamental physical methods and principles, which are sufficient to describe and understand a wide range of seemingly very diverse astrophysical phenomena and processes. For example, the formulae that define the macroscopic behavior of stellar systems are all derived in the same way from the microscopic distribution function. This function it

  3. Astrophysics in a nutshell

    CERN Document Server

    Maoz, Dan

    2016-01-01

    Winner of the American Astronomical Society's Chambliss Award, Astrophysics in a Nutshell has become the text of choice in astrophysics courses for science majors at top universities in North America and beyond. In this expanded and fully updated second edition, the book gets even better, with a new chapter on extrasolar planets; a greatly expanded chapter on the interstellar medium; fully updated facts and figures on all subjects, from the observed properties of white dwarfs to the latest results from precision cosmology; and additional instructive problem sets. Throughout, the text features the same focused, concise style and emphasis on physics intuition that have made the book a favorite of students and teachers.

  4. Surprises in astrophysical gasdynamics.

    Science.gov (United States)

    Balbus, Steven A; Potter, William J

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one's a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject. PMID:27116247

  5. Astrophysics: An Integrative Course

    Science.gov (United States)

    Gutsche, Graham D.

    1975-01-01

    Describes a one semester course in introductory stellar astrophysics at the advanced undergraduate level. The course aims to integrate all previously learned physics by applying it to the study of stars. After a brief introductory section on basic astronomical measurements, the main topics covered are stellar atmospheres, stellar structure, and…

  6. The NASA Astrophysics Program

    Science.gov (United States)

    Zebulum, Ricardo S.

    2011-01-01

    NASA's scientists are enjoying unprecedented access to astronomy data from space, both from missions launched and operated only by NASA, as well as missions led by other space agencies to which NASA contributed instruments or technology. This paper describes the NASA astrophysics program for the next decade, including NASA's response to the ASTRO2010 Decadal Survey.

  7. Surprises in astrophysical gasdynamics

    Science.gov (United States)

    Balbus, Steven A.; Potter, William J.

    2016-06-01

    Much of astrophysics consists of the study of ionized gas under the influence of gravitational and magnetic fields. Thus, it is not possible to understand the astrophysical universe without a detailed knowledge of the dynamics of magnetized fluids. Fluid dynamics is, however, a notoriously tricky subject, in which it is all too easy for one’s a priori intuition to go astray. In this review, we seek to guide the reader through a series of illuminating yet deceptive problems, all with an enlightening twist. We cover a broad range of topics including the instabilities acting in accretion discs, the hydrodynamics governing the convective zone of the Sun, the magnetic shielding of a cooling galaxy cluster, and the behaviour of thermal instabilities and evaporating clouds. The aim of this review is to surprise and intrigue even veteran astrophysical theorists with an idiosyncratic choice of problems and counterintuitive results. At the same time, we endeavour to bring forth the fundamental ideas, to set out important assumptions, and to describe carefully whatever novel techniques may be appropriate to the problem at hand. By beginning at the beginning, and analysing a wide variety of astrophysical settings, we seek not only to make this review suitable for fluid dynamic veterans, but to engage novice recruits as well with what we hope will be an unusual and instructive introduction to the subject.

  8. Laboratory Astrophysics and the State of Astronomy and Astrophysics

    CERN Document Server

    Brickhouse, AAS WGLA: Nancy; Drake, Paul; Federman, Steven; Ferland, Gary; Frank, Adam; Haxton, Wick; Herbst, Eric; Olive, Keith; Salama, Farid; Savin, Daniel Wolf; Ziurys, Lucy

    2009-01-01

    Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomy and astrophysics and will remain so into the foreseeable future. The impact of laboratory astrophysics ranges from the scientific conception stage for ground-based, airborne, and space-based observatories, all the way through to the scientific return of these projects and missions. It is our understanding of the under-lying physical processes and the measurements of critical physical parameters that allows us to address fundamental questions in astronomy and astrophysics. In this regard, laboratory astrophysics is much like detector and instrument development at NASA, NSF, and DOE. These efforts are necessary for the success of astronomical research being funded by the agencies. Without concomitant efforts in all three directions (observational facilities, detector/instrument development, and laboratory astrophysics) the future progress of astronomy and astrophysics is imperiled. In addition, new developments i...

  9. Silica aerogel and space astrophysics

    International Nuclear Information System (INIS)

    Silica aerogels have been produced in large and transparent blocks for space astrophysics experiments since the beginning of the 1970's. They were used in cosmic ray experiments on board balloons by the Saclay group. A new space venture where aerogel Cerenkov radiators will play a decisive role is currently being prepared by a large collaboration of European and US Institutes. It will be part of the so-called International Solar Polar Mission (ISPM) which will explore the heliosphere over the full range of solar latitudes from the ecliptic (equatorial) plane to the magnetic poles of the sun. Comments on properties and long term behaviour of silica aerogel cerenkov radiators in space environment are given

  10. LUNA: Nuclear astrophysics underground

    International Nuclear Information System (INIS)

    Underground nuclear astrophysics with LUNA at the Laboratori Nazionali del Gran Sasso spans a history of 20 years. By using the rock overburden of the Gran Sasso mountain chain as a natural cosmic-ray shield very low signal rates compared to an experiment on the surface can be tolerated. The cross sectons of important astrophysical reactions directly in the stellar energy range have been successfully measured. In this proceeding we give an overview over the key accomplishments of the experiment and an outlook on its future with the expected addition of an additional accelerator to the underground facilities, enabling the coverage of a wider energy range and the measurement of previously inaccessible reactions

  11. Nuclear astrophysics at DRAGON

    Energy Technology Data Exchange (ETDEWEB)

    Hager, U. [Colorado School of Mines, Golden, Colorado (United States)

    2014-05-02

    The DRAGON recoil separator is located at the ISAC facility at TRIUMF, Vancouver. It is designed to measure radiative alpha and proton capture reactions of astrophysical importance. Over the last years, the DRAGON collaboration has measured several reactions using both radioactive and high-intensity stable beams. For example, the 160(a, g) cross section was recently measured. The reaction plays a role in steady-state helium burning in massive stars, where it follows the 12C(a, g) reaction. At astrophysically relevant energies, the reaction proceeds exclusively via direct capture, resulting in a low rate. In this measurement, the unique capabilities of DRAGON enabled determination not only of the total reaction rates, but also of decay branching ratios. In addition, results from other recent measurements will be presented.

  12. Nuclear Astrophysics with LUNA

    Science.gov (United States)

    Broggini, Carlo

    2016-04-01

    One of the main ingredients of nuclear astrophysics is the knowledge of the thermonuclear reactions which power the stars and synthesize the chemical elements. Deep underground in the Gran Sasso Laboratory the cross section of the key reactions of the proton-proton chain and of the Carbon-Nitrogen-Oxygen (CNO) cycle have been measured right down to the energies of astrophysical interest. The main results obtained during the 'solar' phase of LUNA are reviewed and their influence on our understanding of the properties of the neutrino and of the Sun is discussed. We then describe the current LUNA program mainly devoted to the study of the nucleosynthesis of the light elements in AGB stars and Classical Novae. Finally, the future of LUNA towards the study of helium and carbon burning with a new 3.5 MV accelerator is outlined.

  13. Astrophysics a new approach

    CERN Document Server

    Kundt, Wolfgang

    2005-01-01

    For a quantitative understanding of the physics of the universe - from the solar system through the milky way to clusters of galaxies all the way to cosmology - these edited lecture notes are perhaps among the most concise and also among the most critical ones: Astrophysics has not yet stood the redundancy test of laboratory physics, hence should be wary of early interpretations. Special chapters are devoted to magnetic and radiation processes, supernovae, disks, black-hole candidacy, bipolar flows, cosmic rays, gamma-ray bursts, image distortions, and special sources. At the same time, planet earth is viewed as the arena for life, with plants and animals having evolved to homo sapiens during cosmic time. -- This text is unique in covering the basic qualitative and quantitative tools, formulae as well as numbers, needed for the precise interpretation of frontline phenomena in astrophysical research. The author compares mainstream interpretations with new and even controversial ones he wishes to emphasize. The...

  14. LUNA: Nuclear astrophysics underground

    Energy Technology Data Exchange (ETDEWEB)

    Best, A. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Gran Sasso, Assergi (Italy)

    2015-02-24

    Underground nuclear astrophysics with LUNA at the Laboratori Nazionali del Gran Sasso spans a history of 20 years. By using the rock overburden of the Gran Sasso mountain chain as a natural cosmic-ray shield very low signal rates compared to an experiment on the surface can be tolerated. The cross sectons of important astrophysical reactions directly in the stellar energy range have been successfully measured. In this proceeding we give an overview over the key accomplishments of the experiment and an outlook on its future with the expected addition of an additional accelerator to the underground facilities, enabling the coverage of a wider energy range and the measurement of previously inaccessible reactions.

  15. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  16. Numerical Relativity Beyond Astrophysics

    OpenAIRE

    Garfinkle, David

    2016-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black...

  17. Astrophysics in 2006

    CERN Document Server

    Trimble, Virginia; Hansen, Carl J

    2007-01-01

    The fastest pulsar and the slowest nova; the oldest galaxies and the youngest stars; the weirdest life forms and the commonest dwarfs; the highest energy particles and the lowest energy photons. These were some of the extremes of Astrophysics 2006. We attempt also to bring you updates on things of which there is currently only one (habitable planets, the Sun, and the universe) and others of which there are always many, like meteors and molecules, black holes and binaries.

  18. Optics in Astrophysics

    CERN Document Server

    Foy, Renaud

    2005-01-01

    Astrophysics is facing challenging aims such as deep cosmology at redshift higher than 10 to constrain cosmology models, or the detection of exoplanets, and possibly terrestrial exoplanets, and several others. It requires unprecedented ambitious R&D programs, which have definitely to rely on a tight cooperation between astrophysics and optics communities. The book addresses most of the most critical interdisciplinary domains where they interact, or where they will do. A first need is to collect more light, i.e. telescopes still larger than the current 8-10 meter class ones. Decametric, and even hectometric, optical (from UV to IR wavelengths) telescopes are being studied. Whereas up to now the light collecting surface of new telescopes was approximately 4 times that of the previous generation, now this factor is growing to 10 to 100. This quantum leap urges to implement new methods or technologies developed in the optics community, both in academic labs and in the industry. Given the astrophysical goals a...

  19. Integrating Out Astrophysical Uncertainties

    CERN Document Server

    Fox, Patrick J; Weiner, Neal

    2010-01-01

    Underground searches for dark matter involve a complicated interplay of particle physics, nuclear physics, atomic physics and astrophysics. We attempt to remove the uncertainties associated with astrophysics by developing the means to map the observed signal in one experiment directly into a predicted rate at another. We argue that it is possible to make experimental comparisons that are completely free of astrophysical uncertainties by focusing on {\\em integral} quantities, such as $g(v_{min})=\\int_{v_{min}} dv\\, f(v)/v $ and $\\int_{v_{thresh}} dv\\, v g(v)$. Direct comparisons are possible when the $v_{min}$ space probed by different experiments overlap. As examples, we consider the possible dark matter signals at CoGeNT, DAMA and CRESST-Oxygen. We find that expected rate from CoGeNT in the XENON10 experiment is higher than observed, unless scintillation light output is low. Moreover, we determine that S2-only analyses are constraining, unless the charge yield $Q_y< 2.4 {\\, \\rm electrons/keV}$. For DAMA t...

  20. Electrodynamics and spacetime geometry: Astrophysical applications

    CERN Document Server

    Cabral, Francisco

    2016-01-01

    After a brief review of the foundations of (pre-metric) electromagnetism in differential forms, we proceed with the tensor formulation and explore physical consequences of Maxwell's equations in curved spacetime. The generalized Gauss and Maxwell-Amp\\`ere laws, as well as the wave equations, reveal potentially interesting astrophysical applications. The physical implications of these equations are explored and some solutions are obtained. In all cases new electromagnetic couplings and related phenomena are induced by the spacetime curvature. The applications of astrophysical interest considered here correspond essentially to the following geometries: the Schwarzschild spacetime and the spacetime around a rotating spherical mass in the weak field and slow rotation regime. In the latter, we use the Parameterised Post-Newtonian (PPN) formalism. In general, new electromagnetic effects induced by spacetime curvature include the following: Gravitational contributions for the decay of electric and magnetic fields in...

  1. Laboratory Astrophysics: Enabling Scientific Discovery and Understanding

    Science.gov (United States)

    Kirby, K.

    2006-01-01

    NASA's Science Strategic Roadmap for Universe Exploration lays out a series of science objectives on a grand scale and discusses the various missions, over a wide range of wavelengths, which will enable discovery. Astronomical spectroscopy is arguably the most powerful tool we have for exploring the Universe. Experimental and theoretical studies in Laboratory Astrophysics convert "hard-won data into scientific understanding". However, the development of instruments with increasingly high spectroscopic resolution demands atomic and molecular data of unprecedented accuracy and completeness. How to meet these needs, in a time of severe budgetary constraints, poses a significant challenge both to NASA, the astronomical observers and model-builders, and the laboratory astrophysics community. I will discuss these issues, together with some recent examples of productive astronomy/lab astro collaborations.

  2. Exploration

    International Nuclear Information System (INIS)

    Oil and gas exploration is a unique kind of business. Businesses providing a vast and ever-changing panoply of products to markets are a focus of several disciplines' energetic study and analysis. The product inventory problem is robust, pertinent, and meaningful, and it merits the voluminous and protracted attention received from keen business practitioners. Prototypical business practitioners, be they trained by years of business hurly-burly, or sophisticated MBAs with arrays of mathematical algorithms and computers, are not normally prepared, however, to recognize the unique nature of exploration's inventories. Put together such a business practitioner with an explorationist and misunderstandings, hidden and open, are inevitable and predictably rife. The first purpose of this paper is to articulate the inherited inventory handling paradigms of business practitioners in relation to exploration's inventories. To do so, standard pedagogy in business administration is used and a case study of an exploration venture is presented. A second purpose is to show the burdens that the misunderstandings create. The result is not just business plans that go awry, but public policies that have effects opposite from those intended

  3. Laboratory Astrophysics and the State of Astronomy and Astrophysics

    OpenAIRE

    WGLA, AAS; :; Brickhouse, Nancy; Cowan, John; Drake, Paul; Federman, Steven; Ferland, Gary; Frank, Adam; Haxton, Wick; Herbst, Eric; Olive, Keith(School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, U.S.A.); Salama, Farid; Savin, Daniel Wolf; Ziurys, Lucy

    2009-01-01

    Laboratory astrophysics and complementary theoretical calculations are the foundations of astronomy and astrophysics and will remain so into the foreseeable future. The impact of laboratory astrophysics ranges from the scientific conception stage for ground-based, airborne, and space-based observatories, all the way through to the scientific return of these projects and missions. It is our understanding of the under-lying physical processes and the measurements of critical physical parameters...

  4. Nuclear astrophysics with neutrons

    Science.gov (United States)

    Dillmann, I.; Reifarth, R.

    2012-04-01

    Neutrons play a crucial role in astrophysics during the heavy element nucleosynthesis. The largest fraction of isotopes heavier than iron is produced by neutron capture processes on short (r process) and long timescales (s process). During the ``slow neutron capture process'' (s process) heavier elements are produced by successive captures of in-situ produced neutrons from the reactions 13C(α,n)16O and 22Ne(α,n)25Mg (with densities of 106-1010 cm-3) in the interior of stars and following β-decays. With this scenario the reaction path runs along the valley of stability up to 209Bi and produces about 50% of the solar abundances of the heavy elements. Important nuclear physics parameters for s-process nucleosynthesis are neutron capture cross sections (for En = 0.3-300 keV, corresponding to stellar temperatures between kT= 8 and 90 keV) and β-decay half-lives. Neutron capture measurements can be performed via activation in a quasi-stellar neutron spectrum utilizing several (p,n) reactions, or by the time-of-flight technique. The ``rapid neutron capture process'' (r process) is responsible for the remaining 50% of the solar abundances. Here neutrons with densities of 1020-1030 cm-3 are captured on a very fast timescale (ms) during a Core Collapse Supernova in a region close to the forming neutron star. The r-process nuclei are thus very short-lived, neutron-rich isotopes up to the actinides, which can only be produced and investigated at large-scale radioactive-beam facilities. Here the most important nuclear physics parameters are masses, half-lives, and at later stages also β-delayed neutrons. This paper will summarize the role of neutrons in nuclear astrophysics and give a short overview about the related astrophysics programs at the GSI Helmholtz research center and the FRANZ facility in Germany.

  5. General relativity and relativistic astrophysics

    CERN Document Server

    Mukhopadhyay, Banibrata

    2016-01-01

    Einstein established the theory of general relativity and the corresponding field equation in 1915 and its vacuum solutions were obtained by Schwarzschild and Kerr for, respectively, static and rotating black holes, in 1916 and 1963, respectively. They are, however, still playing an indispensable role, even after 100 years of their original discovery, to explain high energy astrophysical phenomena. Application of the solutions of Einstein's equation to resolve astrophysical phenomena has formed an important branch, namely relativistic astrophysics. I devote this article to enlightening some of the current astrophysical problems based on general relativity. However, there seem to be some issues with regard to explaining certain astrophysical phenomena based on Einstein's theory alone. I show that Einstein's theory and its modified form, both are necessary to explain modern astrophysical processes, in particular, those related to compact objects.

  6. LUNA: Nuclear Astrophysics Deep Underground

    OpenAIRE

    Broggini, Carlo; Bemmerer, Daniel; Guglielmetti, Alessandra; Menegazzo, Roberto

    2010-01-01

    Nuclear astrophysics strives for a comprehensive picture of the nuclear reactions responsible for synthesizing the chemical elements and for powering the stellar evolution engine. Deep underground in the Gran Sasso laboratory the cross sections of the key reactions of the proton-proton chain and of the Carbon-Nitrogen-Oxygen (CNO) cycle have been measured right down to the energies of astrophysical interest. The salient features of underground nuclear astrophysics are summarized here. The mai...

  7. Laboratory Mesurements in Nuclear Astrophysics

    OpenAIRE

    Gai, Moshe

    1994-01-01

    After reviewing some of the basic concepts, nomenclatures and parametrizations of Astronomy, Astrophysics and Cosmology, we introduce a few central problems in Nuclear Astrophysics, including the hot-CNO cycle, helium burning in massive stars, and solar neutrino's. We demonstarte that SECONDARY (RADIOACTIVE) NUCLEAR BEAMS allow for considerable progress on these problems.

  8. Exotic nuclei and astrophysics

    Directory of Open Access Journals (Sweden)

    Penionzhkevich Yu.

    2012-12-01

    Full Text Available In recent years, nuclear physics investigations of the laws of the microscopic world contributed significantly to extension of our knowledge of phenomena occurring in the macroscopic world (Universe and made a formidable contribution to the development of astrophysical and cosmological theories. First of all, this concerns the expanding universe model, the evolution of stars, and the abundances of elements, as well as the properties of various stars and cosmic objects, including “cold” and neutron stars, black holes, and pulsars. Without claiming to give a full account of all cosmological problems, we will dwell upon those of them that, in my opinion, have much in common with nuclear-matter properties manifesting themselves in nuclear interactions.

  9. Black-hole astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Bender, P. [Univ. of Colorado, Boulder, CO (United States); Bloom, E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Cominsky, L. [Sonoma State Univ., Rohnert Park, CA (United States). Dept. of Physics and Astronomy] [and others

    1995-07-01

    Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

  10. Instabilities in astrophysical jets

    International Nuclear Information System (INIS)

    Instabilities in astrophysical jets are studied in the nonlinear regime by performing 2D numerical classical gasdynamical calculations. The instabilities which arise from unsteadiness in output from the central engine feeding the jets, and those which arise from a beam in a turbulent surrounding are studied. An extra power output an order of magnitude higher than is normally delivered by the engine over a time equal to (nozzle length)/(sound velocity at centre) causes a nonlinear Kelvin-Helmholtz instability in the jet walls. Constrictions move outwards, but the jet structure is left untouched. A beam in turbulent surroundings produces internal shocks over distances of a few beam widths. If viscosity is present the throughput of material is hampered on time scales of a few beam radius sound travel times. The implications are discussed. (Auth.)

  11. NASA's Astrophysics Data Archives

    Science.gov (United States)

    Hasan, H.; Hanisch, R.; Bredekamp, J.

    2000-09-01

    The NASA Office of Space Science has established a series of archival centers where science data acquired through its space science missions is deposited. The availability of high quality data to the general public through these open archives enables the maximization of science return of the flight missions. The Astrophysics Data Centers Coordinating Council, an informal collaboration of archival centers, coordinates data from five archival centers distiguished primarily by the wavelength range of the data deposited there. Data are available in FITS format. An overview of NASA's data centers and services is presented in this paper. A standard front-end modifyer called `Astrowbrowse' is described. Other catalog browsers and tools include WISARD and AMASE supported by the National Space Scince Data Center, as well as ISAIA, a follow on to Astrobrowse.

  12. Beauty and Astrophysics

    Science.gov (United States)

    Bessell, Michael S.

    2000-08-01

    Spectacular colour images have been made by combining CCD images in three different passbands using Adobe Photoshop. These beautiful images highlight a variety of astrophysical phenomena and should be a valuable resource for science education and public awareness of science. The wide field images were obtained at the Siding Spring Observatory (SSO) by mounting a Hasselblad or Nikkor telephoto lens in front of a 2K × 2K CCD. Options of more than 30 degrees or 6 degrees square coverage are produced in a single exposure in this way. Narrow band or broad band filters were placed between lens and CCD enabling deep, linear images in a variety of passbands to be obtained. We have mapped the LMC and SMC and are mapping the Galactic Plane for comparison with the Molonglo Radio Survey. Higher resolution images have also been made with the 40 inch telescope of galaxies and star forming regions in the Milky Way.

  13. Essential Magnetohydrodynamics for Astrophysics

    CERN Document Server

    Spruit, H C

    2013-01-01

    This text is intended as an introduction to magnetohydrodynamics in astrophysics, emphasizing a fast path to the elements essential for physical understanding. It assumes experience with concepts from fluid mechanics: the fluid equation of motion and the Lagrangian and Eulerian descriptions of fluid flow. In addition, the basics of vector calculus and elementary special relativity are needed. Not much knowledge of electromagnetic theory is required. In fact, since MHD is much closer in spirit to fluid mechanics than to electromagnetism, an important part of the learning curve is to overcome intuitions based on the vacuum electrodynamics of one's high school days. The first chapter (only 36 pp) is meant as a practical introduction including exercises. This is the `essential' part. The exercises are important as illustrations of the points made in the text (especially the less intuitive ones). Almost all are mathematically unchallenging. The supplement in chapter 2 contains further explanations, more specialize...

  14. Numerical Relativity Beyond Astrophysics

    CERN Document Server

    Garfinkle, David

    2016-01-01

    Though the main applications of computer simulations in relativity are to astrophysical systems such as black holes and neutron stars, nonetheless there are important applications of numerical methods to the investigation of general relativity as a fundamental theory of the nature of space and time. This paper gives an overview of some of these applications. In particular we cover (i) investigations of the properties of spacetime singularities such as those that occur in the interior of black holes and in big bang cosmology. (ii) investigations of critical behavior at the threshold of black hole formation in gravitational collapse. (iii) investigations inspired by string theory, in particular analogs of black holes in more than 4 spacetime dimensions and gravitational collapse in spacetimes with a negative cosmological constant.

  15. Photoneutron reactions in astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Varlamov, V. V., E-mail: Varlamov@depni.sinp.msu.ru; Ishkhanov, B. S.; Orlin, V. N.; Peskov, N. N.; Stopani, K. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2014-12-15

    Among key problems in nuclear astrophysics, that of obtaining deeper insight into the mechanism of synthesis of chemical elements is of paramount importance. The majority of heavy elements existing in nature are produced in stars via radiative neutron capture in so-called s- and r processes, which are, respectively, slow and fast, in relation to competing β{sup −}-decay processes. At the same time, we know 35 neutron-deficient so-called bypassed p-nuclei that lie between {sup 74}Se and {sup 196}Hg and which cannot originate from the aforementioned s- and r-processes. Their production is possible in (γ, n), (γ, p), or (γ, α) photonuclear reactions. In view of this, data on photoneutron reactions play an important role in predicting and describing processes leading to the production of p-nuclei. Interest in determining cross sections for photoneutron reactions in the threshold energy region, which is of particular importance for astrophysics, has grown substantially in recent years. The use of modern sources of quasimonoenergetic photons obtained in processes of inverse Compton laser-radiation scattering on relativistic electronsmakes it possible to reveal rather interesting special features of respective cross sections, manifestations of pygmy E1 and M1 resonances, or the production of nuclei in isomeric states, on one hand, and to revisit the problem of systematic discrepancies between data on reaction cross sections from experiments of different types, on the other hand. Data obtained on the basis of our new experimental-theoretical approach to evaluating cross sections for partial photoneutron reactions are invoked in considering these problems.

  16. Theoretical Astrophysics at Fermilab

    Science.gov (United States)

    2004-01-01

    The Theoretical Astrophysics Group works on a broad range of topics ranging from string theory to data analysis in the Sloan Digital Sky Survey. The group is motivated by the belief that a deep understanding of fundamental physics is necessary to explain a wide variety of phenomena in the universe. During the three years 2001-2003 of our previous NASA grant, over 120 papers were written; ten of our postdocs went on to faculty positions; and we hosted or organized many workshops and conferences. Kolb and collaborators focused on the early universe, in particular and models and ramifications of the theory of inflation. They also studied models with extra dimensions, new types of dark matter, and the second order effects of super-horizon perturbations. S tebbins, Frieman, Hui, and Dodelson worked on phenomenological cosmology, extracting cosmological constraints from surveys such as the Sloan Digital Sky Survey. They also worked on theoretical topics such as weak lensing, reionization, and dark energy. This work has proved important to a number of experimental groups [including those at Fermilab] planning future observations. In general, the work of the Theoretical Astrophysics Group has served as a catalyst for experimental projects at Fennilab. An example of this is the Joint Dark Energy Mission. Fennilab is now a member of SNAP, and much of the work done here is by people formerly working on the accelerator. We have created an environment where many of these people made transition from physics to astronomy. We also worked on many other topics related to NASA s focus: cosmic rays, dark matter, the Sunyaev-Zel dovich effect, the galaxy distribution in the universe, and the Lyman alpha forest. The group organized and hosted a number of conferences and workshop over the years covered by the grant. Among them were:

  17. Goddard's Astrophysics Science Divsion Annual Report 2014

    Science.gov (United States)

    Weaver, Kimberly (Editor); Reddy, Francis (Editor); Tyler, Pat (Editor)

    2015-01-01

    The Astrophysics Science Division (ASD, Code 660) is one of the world's largest and most diverse astronomical organizations. Space flight missions are conceived, built and launched to observe the entire range of the electromagnetic spectrum, from gamma rays to centimeter waves. In addition, experiments are flown to gather data on high-energy cosmic rays, and plans are being made to detect gravitational radiation from space-borne missions. To enable these missions, we have vigorous programs of instrument and detector development. Division scientists also carry out preparatory theoretical work and subsequent data analysis and modeling. In addition to space flight missions, we have a vibrant suborbital program with numerous sounding rocket and balloon payloads in development or operation. The ASD is organized into five labs: the Astroparticle Physics Lab, the X-ray Astrophysics Lab, the Gravitational Astrophysics Lab, the Observational Cosmology Lab, and the Exoplanets and Stellar Astrophysics Lab. The High Energy Astrophysics Science Archive Research Center (HEASARC) is an Office at the Division level. Approximately 400 scientists and engineers work in ASD. Of these, 80 are civil servant scientists, while the rest are resident university-based scientists, contractors, postdoctoral fellows, graduate students, and administrative staff. We currently operate the Swift Explorer mission and the Fermi Gamma-ray Space Telescope. In addition, we provide data archiving and operational support for the XMM mission (jointly with ESA) and the Suzaku mission (with JAXA). We are also a partner with Caltech on the NuSTAR mission. The Hubble Space Telescope Project is headquartered at Goddard, and ASD provides Project Scientists to oversee operations at the Space Telescope Science Institute. Projects in development include the Neutron Interior Composition Explorer (NICER) mission, an X-ray timing experiment for the International Space Station; the Transiting Exoplanet Sky Survey (TESS

  18. NASA Astrophysics Funds Strategic Technology Development

    Science.gov (United States)

    Seery, Bernard D.; Ganel, Opher; Pham, Bruce

    2016-01-01

    The COR and PCOS Program Offices (POs) reside at the NASA Goddard Space Flight Center (GSFC), serving as the NASA Astrophysics Division's implementation arm for matters relating to the two programs. One aspect of the PO's activities is managing the COR and PCOS Strategic Astrophysics Technology (SAT) program, helping mature technologies to enable and enhance future astrophysics missions. For example, the SAT program is expected to fund key technology developments needed to close gaps identified by Science and Technology Definition Teams (STDTs) planned to study several large mission concept studies in preparation for the 2020 Decadal Survey.The POs are guided by the National Research Council's "New Worlds, New Horizons in Astronomy and Astrophysics" Decadal Survey report, NASA's Astrophysics Implementation Plan, and the visionary Astrophysics Roadmap, "Enduring Quests, Daring Visions." Strategic goals include dark energy, gravitational waves, and X-ray observatories. Future missions pursuing these goals include, e.g., US participation in ESA's Euclid, Athena, and L3 missions; Inflation probe; and a large UV/Optical/IR (LUVOIR) telescope.To date, 65 COR and 71 PCOS SAT proposals have been received, of which 15 COR and 22 PCOS projects were funded. Notable successes include maturation of a new far-IR detector, later adopted by the SOFIA HAWC instrument; maturation of the H4RG near-IR detector, adopted by WFIRST; development of an antenna-coupled transition-edge superconducting bolometer, a technology deployed by BICEP2/BICEP3/Keck to measure polarization in the CMB signal; advanced UV reflective coatings implemented on the optics of GOLD and ICON, two heliophysics Explorers; and finally, the REXIS instrument on OSIRIS-REx is incorporating CCDs with directly deposited optical blocking filters developed by another SAT-funded project.We discuss our technology development process, with community input and strategic prioritization informing calls for SAT proposals and

  19. Astrophysical components from Planck maps

    CERN Document Server

    Burigana, Carlo; Paoletti, Daniela; Mandolesi, Nazzareno; Natoli, Paolo

    2016-01-01

    The Planck Collaboration has recently released maps of the microwave sky in both temperature and polarization. Diffuse astrophysical components (including Galactic emissions, cosmic far infrared (IR) background, y-maps of the thermal Sunyaev-Zeldovich (SZ) effect) and catalogs of many thousands of Galactic and extragalactic radio and far-IR sources, and galaxy clusters detected through the SZ effect are the main astrophysical products of the mission. A concise overview of these results and of astrophysical studies based on Planck data is presented.

  20. Astrophysical Smooth Particle Hydrodynamics

    CERN Document Server

    Rosswog, Stephan

    2009-01-01

    In this review the basic principles of smooth particle hydrodynamics (SPH) are outlined in a pedagogical fashion. To start, a basic set of SPH equations that is used in many codes throughout the astrophysics community is derived explicitly. Much of SPH's success relies on its excellent conservation properties and therefore the numerical conservation of physical invariants receives much attention throughout this review. The self-consistent derivation of the SPH equations from the Lagrangian of an ideal fluid is the common theme of the remainder of the text. Such a variational approach is applied to derive a modern SPH version of Newtonian hydrodynamics. It accounts for gradients in the local resolution lengths which result in corrective, so-called "grad-h-terms". This strategy naturally carries over to the special-relativistic case for which we derive the corresponding grad-h set of equations. This approach is further generalized to the case of a fluid that evolves on a curved, but fixed background space-time.

  1. Atoms in astrophysics

    CERN Document Server

    Eissner, W; Hummer, D; Percival, I

    1983-01-01

    It is hard to appreciate but nevertheless true that Michael John Seaton, known internationally for the enthusiasm and skill with which he pursues his research in atomic physics and astrophysics, will be sixty years old on the 16th of January 1983. To mark this occasion some of his colleagues and former students have prepared this volume. It contains articles that de­ scribe some of the topics that have attracted his attention since he first started his research work at University College London so many years ago. Seaton's association with University College London has now stretched over a period of some 37 years, first as an undergraduate student, then as a research student, and then, successively, as Assistant Lecturer, Lecturer, Reader, and Professor. Seaton arrived at University College London in 1946 to become an undergraduate in the Physics Department, having just left the Royal Air Force in which he had served as a navigator in the Pathfinder Force of Bomber Command. There are a number of stories of ho...

  2. Byurakan Astrophysical Observatory

    Science.gov (United States)

    Mickaelian, A. M.

    2016-09-01

    This booklet is devoted to NAS RA V. Ambartsumian Byurakan Astrophysical Observatory and is aimed at people interested in astronomy and BAO, pupils and students, BAO visitors and others. The booklet is made as a visiting card and presents concise and full information about BAO. A brief history of BAO, the biography of the great scientist Viktor Ambartsumian, brief biographies of 13 other deserved scientists formerly working at BAO (B.E. Markarian, G.A. Gurzadyan, L.V. Mirzoyan, M.A. Arakelian, et al.), information on BAO telescopes (2.6m, 1m Schmidt, etc.) and other scientific instruments, scientific library and photographic plate archive, Byurakan surveys (including the famous Markarian Survey included in the UNESCO Memory of the World International Register), all scientific meetings held in Byurakan, international scientific collaboration, data on full research staff of the Observatory, as well as former BAO researchers, who have moved to foreign institutions are given in the booklet. At the end, the list of the most important books published by Armenian astronomers and about them is given.

  3. The Wisconsin Plasma Astrophysics Laboratory

    CERN Document Server

    Forest, C B; Brookhart, M; Cooper, C M; Clark, M; Desangles, V; Egedal, J; Endrizzi, D; Miesch, M; Khalzov, I V; Li, H; Milhone, J; Nornberg, M; Olson, J; Peterson, E; Roesler, F; Schekochihin, A; Schmitz, O; Siller, R; Spitkovsky, A; Stemo, A; Wallace, J; Weisberg, D; Zweibel, E

    2015-01-01

    The Wisconsin Plasma Astrophysics Laboratory (WiPAL) is a flexible user facility designed to study a range of astrophysically relevant plasma processes as well as novel geometries which mimic astrophysical systems. A multi-cusp magnetic bucket constructed from strong samarium cobalt permanent magnets now confines a 10 m$^3$, fully ionized, magnetic-field free plasma in a spherical geometry. Plasma parameters of $ T_{e}\\approx5-20$ eV and $n_{e}\\approx10^{11}-5\\times10^{12}$ cm$^{-3}$ provide an ideal testbed for a range of astrophysical experiments including self-exciting dynamos, collisionless magnetic reconnection, jet stability, stellar winds, and more. This article describes the capabilities of WiPAL along with several experiments, in both operating and planning stages, that illustrate the range of possibilities for future users.

  4. An introduction to observational astrophysics

    CERN Document Server

    Gallaway, Mark

    2016-01-01

    Observational Astrophysics follows the general outline of an astrophysics undergraduate curriculum targeting practical observing information to what will be covered at the university level. This includes the basics of optics and coordinate systems to the technical details of CCD imaging, photometry, spectography and radio astronomy.  General enough to be used by students at a variety of institutions and advanced enough to be far more useful than observing guides targeted at amateurs, the author provides a comprehensive and up-to-date treatment of observational astrophysics at undergraduate level to be used with a university’s teaching telescope.  The practical approach takes the reader from basic first year techniques to those required for a final year project. Using this textbook as a resource, students can easily become conversant in the practical aspects of astrophysics in the field as opposed to the classroom.

  5. LUNA: Nuclear Astrophysics Deep Underground

    CERN Document Server

    Broggini, Carlo; Guglielmetti, Alessandra; Menegazzo, Roberto

    2010-01-01

    Nuclear astrophysics strives for a comprehensive picture of the nuclear reactions responsible for synthesizing the chemical elements and for powering the stellar evolution engine. Deep underground in the Gran Sasso laboratory the cross sections of the key reactions of the proton-proton chain and of the Carbon-Nitrogen-Oxygen (CNO) cycle have been measured right down to the energies of astrophysical interest. The salient features of underground nuclear astrophysics are summarized here. The main results obtained by LUNA in the last twenty years are reviewed, and their influence on the comprehension of the properties of the neutrino, of the Sun and of the Universe itself are discussed. Future directions of underground nuclear astrophysics towards the study of helium and carbon burning and of stellar neutron sources in stars are pointed out.

  6. Three Puzzles from Nuclear Astrophysics

    OpenAIRE

    Haxton, W. C.

    2012-01-01

    I discuss three open problems in astrophysics where nuclear physics can make important contributions: the solar abundance problem, dark matter particle detection, and the origin of the r-process elements.

  7. Recent results in nuclear astrophysics

    CERN Document Server

    Coc, Alain; Kiener, Juergen

    2016-01-01

    In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified e.g. 12C(alpha,gamma)16O for stellar evolution, or 13C(alpha,n)16O and 22Ne(alpha,n)25Mg as neutron sources for the s-process. More recently, observations of lithium abundances in the oldest stars, or of nuclear gamma-ray lines from space, have required new laboratory experiments. New evaluation of thermonuclear reaction rates now includes the associated rate uncertainties that are used in astrophysical models to i) estimate final uncertainties on nucleosynthesis yields and ii) identify those reactions that require further experimental investigation. Sometimes direct cross section measurements are possible, but more generally the use of indirect methods is compulsory in view of the very low cross sections. Non-thermal processes are often overlooked but are also important for nuclear astrophysics,...

  8. Nuclear Data for Astrophysical Modeling

    CERN Document Server

    Pritychenko, Boris

    2016-01-01

    Nuclear physics has been playing an important role in modern astrophysics and cosmology. Since the early 1950's it has been successfully applied for the interpretation and prediction of astrophysical phenomena. Nuclear physics models helped to explain the observed elemental and isotopic abundances and star evolution and provided valuable insights on the Big Bang theory. Today, the variety of elements observed in stellar surfaces, solar system and cosmic rays, and isotope abundances are calculated and compared with the observed values. Consequently, the overall success of the modeling critically depends on the quality of underlying nuclear data that helps to bring physics of macro and micro scales together. To broaden the scope of traditional nuclear astrophysics activities and produce additional complementary information, I will investigate applicability of the U.S. Nuclear Data Program (USNDP) databases for astrophysical applications. EXFOR (Experimental Nuclear Reaction Data) and ENDF (Evaluated Nuclear Dat...

  9. The Fermilab Particle Astrophysics Center

    Energy Technology Data Exchange (ETDEWEB)

    2004-11-01

    The Particle Astrophysics Center was established in fall of 2004. Fermilab director Michael S. Witherell has named Fermilab cosmologist Edward ''Rocky'' Kolb as its first director. The Center will function as an intellectual focus for particle astrophysics at Fermilab, bringing together the Theoretical and Experimental Astrophysics Groups. It also encompasses existing astrophysics projects, including the Sloan Digital Sky Survey, the Cryogenic Dark Matter Search, and the Pierre Auger Cosmic Ray Observatory, as well as proposed projects, including the SuperNova Acceleration Probe to study dark energy as part of the Joint Dark Energy Mission, and the ground-based Dark Energy Survey aimed at measuring the dark energy equation of state.

  10. Some aspects of neutrino astrophysics

    CERN Document Server

    Athar, H

    2002-01-01

    Selected topics in neutrino astrophysics are reviewed. These include the production of low energy neutrino flux from cores of collapsing stars and the expected high energy neutrino flux from some other astrophysical sites such as the galactic plane as well as the center of some distant galaxies. The expected changes in these neutrino fluxes because of neutrino oscillations during their propagation to us are described. Observational signatures for these neutrino fluxes with and without neutrino oscillations are discussed.

  11. An introduction to astrophysical hydrodynamics

    CERN Document Server

    Shore, Steven N

    1992-01-01

    This book is an introduction to astrophysical hydrodynamics for both astronomy and physics students. It provides a comprehensive and unified view of the general problems associated with fluids in a cosmic context, with a discussion of fluid dynamics and plasma physics. It is the only book on hydrodynamics that addresses the astrophysical context. Researchers and students will find this work to be an exceptional reference. Contents include chapters on irrotational and rotational flows, turbulence, magnetohydrodynamics, and instabilities.

  12. Nuclear astrophysics from direct reactions

    OpenAIRE

    2008-01-01

    Accurate nuclear reaction rates are needed for primordial nucleosynthesis and hydrostatic burning in stars. The relevant reactions are extremely difficult to measure directly in the laboratory at the small astrophysical energies. In recent years direct reactions have been developed and applied to extract low-energy astrophysical S-factors. These methods require a combination of new experimental techniques and theoretical efforts, which are the subject of this presentation.

  13. Minicourses in Astrophysics, Modular Approach, Vol. I.

    Science.gov (United States)

    Illinois Univ., Chicago.

    This is the first volume of a two-volume minicourse in astrophysics. It contains chapters on the following topics: planetary atmospheres; X-ray astronomy; radio astrophysics; molecular astrophysics; and gamma-ray astrophysics. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are included with…

  14. High energy astrophysics. An introduction

    International Nuclear Information System (INIS)

    Based on observational examples this book reveals and explains high-energy astrophysical processes. Presents the theory of astrophysical processes in a didactic approach by deriving equations step by step. With several attractive astronomical pictures. High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad basis on which they should be able to build the more specific knowledge they will need. While in the first part of the book the physical processes are described and derived in detail, the second part studies astrophysical objects in which high-energy astrophysics plays a crucial role. This two-pronged approach will help students recognise physical processes by their observational signatures in contexts that may differ widely from those presented here.

  15. High energy astrophysics. An introduction

    Energy Technology Data Exchange (ETDEWEB)

    Courvoisier, Thierry J.L. [Geneva Univ., Versoix (Switzerland). ISDC, Data Centre for Astrophysics

    2013-07-01

    Based on observational examples this book reveals and explains high-energy astrophysical processes. Presents the theory of astrophysical processes in a didactic approach by deriving equations step by step. With several attractive astronomical pictures. High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad basis on which they should be able to build the more specific knowledge they will need. While in the first part of the book the physical processes are described and derived in detail, the second part studies astrophysical objects in which high-energy astrophysics plays a crucial role. This two-pronged approach will help students recognise physical processes by their observational signatures in contexts that may differ widely from those presented here.

  16. Ultrashort electron pulses as a four-dimensional diagnosis of plasma dynamics.

    Science.gov (United States)

    Zhu, P F; Zhang, Z C; Chen, L; Li, R Z; Li, J J; Wang, X; Cao, J M; Sheng, Z M; Zhang, J

    2010-10-01

    We report an ultrafast electron imaging system for real-time examination of ultrafast plasma dynamics in four dimensions. It consists of a femtosecond pulsed electron gun and a two-dimensional single electron detector. The device has an unprecedented capability of acquiring a high-quality shadowgraph image with a single ultrashort electron pulse, thus permitting the measurement of irreversible processes using a single-shot scheme. In a prototype experiment of laser-induced plasma of a metal target under moderate pump intensity, we demonstrated its unique capability of acquiring high-quality shadowgraph images on a micron scale with a-few-picosecond time resolution. PMID:21034089

  17. Ultrashort electron pulses as a four-dimensional diagnosis of plasma dynamics

    International Nuclear Information System (INIS)

    We report an ultrafast electron imaging system for real-time examination of ultrafast plasma dynamics in four dimensions. It consists of a femtosecond pulsed electron gun and a two-dimensional single electron detector. The device has an unprecedented capability of acquiring a high-quality shadowgraph image with a single ultrashort electron pulse, thus permitting the measurement of irreversible processes using a single-shot scheme. In a prototype experiment of laser-induced plasma of a metal target under moderate pump intensity, we demonstrated its unique capability of acquiring high-quality shadowgraph images on a micron scale with a-few-picosecond time resolution.

  18. White Paper on Nuclear Astrophysics

    CERN Document Server

    Arcones, Almudena; Beers, Timothy; Berstein, Lee; Blackmon, Jeff; Bronson, Messer; Brown, Alex; Brown, Edward; Brune, Carl; Champagne, Art; Chieffi, Alessandro; Couture, Aaron; Danielewicz, Pawel; Diehl, Roland; El-Eid, Mounib; Escher, Jutta; Fields, Brian; Frohlich, Carla; Herwig, Falk; Hix, William Raphael; Iliadis, Christian; Lynch, William; McLaughlin, Gail; Meyer, Bradley; Mezzacappa, Anthony; Nunes, Filomena; O'Shea, Brian; Prakash, Madappa; Pritychenko, Boris; Reddy, Sanjay; Rehm, Ernst; Rogachev, Grigory; Rutledge, Robert; Schatz, Hendrik; Smith, Michael; Stairs, Ingrid; Steiner, Andrew; Strohmayer, Tod; Timmes, Frank; Townsley, Dean; Wiescher, Michael; Zegers, Remco; Zingale, Michael

    2016-01-01

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21-23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9- 10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12-13, 2014. In summ...

  19. Constraints of noncommutativity from Astrophysical studies

    CERN Document Server

    Garcia-Aspeitia, Miguel A; Ortiz, C; Hinojosa-Ruiz, Sinhue; Rodriguez-Meza, Mario A

    2015-01-01

    This paper is devoted to study the astrophysical consequences of noncommutativity, focusing in stellar dynamics and rotational curves of galaxies. We start exploring a star filled with an incompressible fluid and a noncommutative fluid under the Tolman-Oppenheimer-Volkoff background. We analyze the effective pressure and mass, resulting in a constraint for the noncommutative parameter. Also we explore the rotation curves of galaxies assuming that the dark matter halo is a noncommutative fluid, obtaining an average value of the noncommutative parameter through an analysis of twelve LSB galaxies; our results are compared with traditional models like Pseudoisothermal, Navarro-Frenk-White and Burkert. As a final remark, we summarize our results as: $\\sqrt{\\theta}>0.075R$, from star constraints which is strong dependent of the stellar radius and $\\langle\\sqrt{\\theta}\\rangle\\simeq2.666\\rm kpc$ with standard deviation $\\sigma\\simeq1.090\\rm kpc$ from the galactic constraints.

  20. Astrophysics a very short introduction

    CERN Document Server

    Binney, James

    2016-01-01

    Astrophysics is the physics of the stars, and more widely the physics of the Universe. It enables us to understand the structure and evolution of planetary systems, stars, galaxies, interstellar gas, and the cosmos as a whole. In this Very Short Introduction, the leading astrophysicist James Binney shows how the field of astrophysics has expanded rapidly in the past century, with vast quantities of data gathered by telescopes exploiting all parts of the electromagnetic spectrum, combined with the rapid advance of computing power, which has allowed increasingly effective mathematical modelling. He illustrates how the application of fundamental principles of physics - the consideration of energy and mass, and momentum - and the two pillars of relativity and quantum mechanics, has provided insights into phenomena ranging from rapidly spinning millisecond pulsars to the collision of giant spiral galaxies. This is a clear, rigorous introduction to astrophysics for those keen to cut their teeth on a conceptual trea...

  1. Radiative Magnetic Reconnection in Astrophysics

    CERN Document Server

    Uzdensky, Dmitri A

    2015-01-01

    I review a new rapidly growing area of high-energy plasma astrophysics --- radiative magnetic reconnection, i.e., a reconnection regime where radiation reaction influences reconnection dynamics, energetics, and nonthermal particle acceleration. This influence be may be manifested via a number of astrophysically important radiative effects, such as radiation-reaction limits on particle acceleration, radiative cooling, radiative resistivity, braking of reconnection outflows by radiation drag, radiation pressure, viscosity, and even pair creation at highest energy densities. Self-consistent inclusion of these effects in magnetic reconnection theory and modeling calls for serious modifications to our overall theoretical approach to the problem. In addition, prompt reconnection-powered radiation often represents our only observational diagnostic tool for studying remote astrophysical systems; this underscores the importance of developing predictive modeling capabilities to connect the underlying physical condition...

  2. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  3. The Astrophysical Multipurpose Software Environment

    CERN Document Server

    Pelupessy, F I; de Vries, N; McMillan, S L W; Drost, N; Zwart, S F Portegies

    2013-01-01

    We present the open source Astrophysical Multi-purpose Software Environment (AMUSE, www.amusecode.org), a component library for performing astrophysical simulations involving different physical domains and scales. It couples existing codes within a Python framework based on a communication layer using MPI. The interfaces are standardized for each domain and their implementation based on MPI guarantees that the whole framework is well-suited for distributed computation. It includes facilities for unit handling and data storage. Currently it includes codes for gravitational dynamics, stellar evolution, hydrodynamics and radiative transfer. Within each domain the interfaces to the codes are as similar as possible. We describe the design and implementation of AMUSE, as well as the main components and community codes currently supported and we discuss the code interactions facilitated by the framework. Additionally, we demonstrate how AMUSE can be used to resolve complex astrophysical problems by presenting exampl...

  4. Smoothed Particle Hydrodynamics in Astrophysics

    CERN Document Server

    Springel, Volker

    2011-01-01

    This review discusses Smoothed Particle Hydrodynamics (SPH) in the astrophysical context, with a focus on inviscid gas dynamics. The particle-based SPH technique allows an intuitive and simple formulation of hydrodynamics that has excellent conservation properties and can be coupled to self-gravity easily and highly accurately. The Lagrangian character of SPH allows it to automatically adjust its resolution to the clumping of matter, a property that makes the scheme ideal for many applications in astrophysics, where often a large dynamic range in density is encountered. We discuss the derivation of the basic SPH equations in their modern formulation, and give an overview about extensions of SPH developed to treat physics such as radiative transfer, thermal conduction, relativistic dynamics or magnetic fields. We also briefly describe some of the most important applications areas of SPH in astrophysical research. Finally, we provide a critical discussion of the accuracy of SPH for different hydrodynamical prob...

  5. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1963-01-01

    Advances in Astronomy and Astrophysics, Volume 2 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of six chapters and begins with a summary of observational record on twilight extensions of the Venus cusps. The next chapter deals with the common and related properties of binary stars, with emphasis on the evaluation of their cataclysmic variables. Cataclysmic variables refer to an object in one of three classes: dwarf nova, nova, or supernova. These topics are followed by discussions on the eclipse phenomena and the eclipses i

  6. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1962-01-01

    Advances in Astronomy and Astrophysics, Volume 1 brings together numerous research works on different aspects of astronomy and astrophysics. This book is divided into five chapters and begins with an observational summary of the shock-wave theory of novae. The subsequent chapter provides the properties and problems of T tauri stars and related objects. These topics are followed by discussions on the structure and origin of meteorites and cosmic dust, as well as the models for evaluation of mass distribution in oblate stellar systems. The final chapter describes the methods of polarization mea

  7. Advances in astronomy and astrophysics

    CERN Document Server

    Kopal, Zdenek

    1966-01-01

    Advances in Astronomy and Astrophysics, Volume 4 brings together numerous research works on different aspects of astronomy and astrophysics. This volume is composed of five chapters, and starts with a description of objective prism and its application in space observations. The next chapter deals with the possibilities of deriving reliable models of the figure, density distribution, and gravity field of the Moon based on data obtained through Earth-bound telescopes. These topics are followed by a discussion on the ideal partially relativistic, partially degenerate gas in an exact manner. A ch

  8. Nuclear astrophysics lessons from INTEGRAL.

    Science.gov (United States)

    Diehl, Roland

    2013-02-01

    Measurements of high-energy photons from cosmic sources of nuclear radiation through ESA's INTEGRAL mission have advanced our knowledge: new data with high spectral resolution showed that characteristic gamma-ray lines from radioactive decays occur throughout the Galaxy in its interstellar medium. Although the number of detected sources and often the significance of the astrophysical results remain modest, conclusions derived from this unique astronomical window of radiation originating from nuclear processes are important, complementing the widely-employed atomic-line based spectroscopy. We review the results and insights obtained in the past decade from gamma-ray line measurements of cosmic sources in the context of their astrophysical questions.

  9. Recent advances in neutrino astrophysics

    CERN Document Server

    Volpe, Cristina

    2014-01-01

    Neutrinos are produced by a variety of sources that comprise our Sun, explosive environments such as core-collapse supernovae, the Earth and the Early Universe. The precise origin of the recently discovered ultra-high energy neutrinos is to be determined yet. These weakly interacting particles give us information on their sources, although the neutrino fluxes can be modified when neutrinos traverse an astrophysical environment. Here we highlight recent advances in neutrino astrophysics and emphasise the important progress in our understanding of neutrino flavour conversion in media.

  10. Nuclear astrophysics data at ORNL

    International Nuclear Information System (INIS)

    There is a new program of evaluation and dissemination of nuclear data of critical importance for nuclear astrophysics within the Physics Division of Oak Ridge National Laboratory. Recent activities include determining the rates of the important 14O(α,p)17 F and 17F(p,γ) 18Ne reactions, disseminating the Caughlan and Fowler reaction rate compilation on the World Wide Web, and evaluating the 17O(p,α)14N reaction rate. These projects, which are closely coupled to current ORNL nuclear astrophysics research, are briefly discussed along with future plans

  11. Explosive-Emission Plasma Dynamics in Ion Diode in Double-Pulse Mode%Explosive-Emission Plasma Dynamics in Ion Diode in Double-Pulse Mode

    Institute of Scientific and Technical Information of China (English)

    Alexander I. PUSHKAREV; Yulia I. ISAKOVA

    2011-01-01

    The results of an experimental investigation of explosive-emission plasma dynamics in an ion diode with self-magnetic insulation are presented. The investigations were accomplished at the TEMP-4M accelerator set in a mode of double pulse formation. Plasma behaviour in the anode-cathode gap was analyzed according to both the current-voltage characteristics of the diode (time resolution of 0.5 ns) and thermal imprints on a target (spatial resolution of 0.8 mm). It was shown that when plasma formation at the potential electrode was complete, and up until the second (positive) pulse, the explosive-emission plasma expanded across the anode-cathode gap with a speed of 1.3±0.2 cm/μs. After the voltage polarity at the potential electrode was reversed (second pulse), the plasma erosion in the anode-cathode gap (similar to the effect of a plasma opening switch) occurred. During the generation of an ion beam the size of the anode-cathode gap spacing was determined by the thickness of the plasma layer on the potential electrode and the layer thickness of the electrons drifting along the grounded electrode.

  12. Astrophysics at very high energies

    International Nuclear Information System (INIS)

    Presents three complementary lectures on very-high-energy astrophysics given by worldwide leaders in the field. Reviews the recent advances in and prospects of gamma-ray astrophysics and of multi-messenger astronomy. Prepares readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors. With the success of Cherenkov Astronomy and more recently with the launch of NASA's Fermi mission, very-high-energy astrophysics has undergone a revolution in the last years. This book provides three comprehensive and up-to-date reviews of the recent advances in gamma-ray astrophysics and of multi-messenger astronomy. Felix Aharonian and Charles Dermer address our current knowledge on the sources of GeV and TeV photons, gleaned from the precise measurements made by the new instrumentation. Lars Bergstroem presents the challenges and prospects of astro-particle physics with a particular emphasis on the detection of dark matter candidates. The topics covered by the 40th Saas-Fee Course present the capabilities of current instrumentation and the physics at play in sources of very-high-energy radiation to students and researchers alike. This book will encourage and prepare readers for using space and ground-based gamma-ray observatories, as well as neutrino and other multi-messenger detectors.

  13. Chaos and complexity in astrophysics

    CERN Document Server

    Regev, Oded

    2007-01-01

    Methods and techniques of the theory of nonlinear dynamical systems and patterns can be useful in astrophysical applications. Some works on the subjects of dynamical astronomy, stellar pulsation and variability, as well as spatial complexity in extended systems, in which such approaches have already been utilized, are reviewed. Prospects for future directions in applications of this kind are outlined.

  14. Indirect methods in nuclear astrophysics

    CERN Document Server

    Bertulani, C A; Mukhamedzhanov, A; Kadyrov, A S; Kruppa, A; Pang, D Y

    2015-01-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions.

  15. Recent Progress in Nuclear Astrophysics

    OpenAIRE

    Langanke, K

    1999-01-01

    The manuscript reviews progress achieved in recent years in various aspects of nuclear astrophysics, including stellar nucleosynthesis, nuclear aspects of supernova collapse and explosion, neutrino-induced reactions and their possible role in the supernova mechanism and nucleosynthesis, explosive hydrogen burning in binary systems, and finally the observation of $\\gamma$-rays from supernova remnants.

  16. Neutrino in Astrophysics and Cosmology

    OpenAIRE

    Dai, Zuxiang

    2003-01-01

    At first we introduce the Neutrino in the standard Model, then the Dirac and Majorana Masses. After introducing the See-Saw Mechanism, we discuss the neutrino oscillations and the neutrino in astrophysics and cosmology. We finish this paper with a brief summary of the neutrino experiments.

  17. Astronomy & Astrophysics: an international journal

    Science.gov (United States)

    Bertout, C.

    2011-07-01

    After a brief historical introduction, we review the scope, editorial process, and production organization of A&A, one of the leading journals worldwide dedicated to publishing the results of astrophysical research. We then briefly discuss the economic model of the Journal and some current issues in scientific publishing.

  18. Astronomy and Astrophysics in India

    Science.gov (United States)

    Narlikar, J.; Murdin, P.

    2001-07-01

    The growth in astronomy and astrophysics (A&A) in India has been mostly since the country achieved independence in 1947. The present work is carried out in a few select research institutes and in some university departments. The Astronomical Society of India has around 300 working A&A scientists as members, with another 50-60 graduate students....

  19. Astrophysics on the Lab Bench

    Science.gov (United States)

    Hughes, Stephen W.

    2010-01-01

    In this article some basic laboratory bench experiments are described that are useful for teaching high school students some of the basic principles of stellar astrophysics. For example, in one experiment, students slam a plastic water-filled bottle down onto a bench, ejecting water towards the ceiling, illustrating the physics associated with a…

  20. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

    A review of nuclear astrophysics of light nuclei using radioactive beams or techniques developed for radioactive beams is given. We discuss Big Bang nucleosynthesis, with special focus on the lithium problem, aspects of neutrino-physics, helium-burning and finally selected examples of studies...

  1. An introduction to nuclear astrophysics

    International Nuclear Information System (INIS)

    The role of nuclear reactions in astrophysics is described. Stellar energy generation and heavy element nucleosynthesis is explained in terms of specific sequences of charged-particle and neutron induced reactions. The evolution and final states of stars are examined. 20 refs. 11 figs., 2 tabs

  2. Indirect methods in nuclear astrophysics

    Science.gov (United States)

    Bertulani, C. A.; Shubhchintak; Mukhamedzhanov, A.; Kadyrov, A. S.; Kruppa, A.; Pang, D. Y.

    2016-04-01

    We discuss recent developments in indirect methods used in nuclear astrophysics to determine the capture cross sections and subsequent rates of various stellar burning processes, when it is difficult to perform the corresponding direct measurements. We discuss in brief, the basic concepts of Asymptotic Normalization Coefficients, the Trojan Horse Method, the Coulomb Dissociation Method, (d,p), and charge-exchange reactions.

  3. Introducing Astrophysics Research to High School Students.

    Science.gov (United States)

    Etkina, Eugenia; Lawrence, Michael; Charney, Jeff

    1999-01-01

    Presents an analysis of an astrophysics institute designed for high school students. Investigates how students respond cognitively in an active science-learning environment in which they serve as apprentices to university astrophysics professors. (Author/CCM)

  4. International Olympiad on Astronomy and Astrophysics

    Science.gov (United States)

    Soonthornthum, B.; Kunjaya, C.

    2011-01-01

    The International Olympiad on Astronomy and Astrophysics, an annual astronomy and astrophysics competition for high school students, is described. Examples of problems and solutions from the competition are also given. (Contains 3 figures.)

  5. Precision laboratory measurements in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Gai, M. [Connecticut Univ., Storrs, CT (United States). Dept. of Physics

    2000-07-01

    After reviewing some of the basic concepts, nomenclatures and parametrizations of astronomy, astrophysics, cosmology, and nuclear physics, we introduce a few central problems in nuclear astrophysics, including the hot-CNO cycle, helium burning and solar neutrinos. We demonstrate that in this new era of precision nuclear astrophysics secondary or radioactive nuclear beams allow for progress. (orig.)

  6. Cathode configuration influence on low-inductance vacuum spark plasma dynamics

    Science.gov (United States)

    Sarantsev, S. A.; Dvoeglazov, Ya M.; Dodulad, E. I.; Raevsky, I. F.; Savjolov, A. S.

    2016-09-01

    The results of studies of cathode configuration influence on high current low- inductance vacuum spark (HLVS) plasma dynamics are presented in this work. The research was carried out on “PION” installation using shadowgraphy method. Molecular nitrogen laser (λ = 337 nm) was used as a radiation source. It was determined that the HLVS behavior changes with the increase of number of discharges. In a fresh electrode system (less than 200 discharges) the dependence of constriction position on the discharge trigger position is observed during HLVS development. Also, high gradients of plasma density and secondary constrictions are observed. In a previously exploited electrode system (more than 300 discharges) HLVS behavior changes: plasma density gradients become less expressed, secondary constrictions disappear. In electrode systems with highly developed cathode surface plasma density gradient distribution pattern only slightly changes from discharge to discharge, e.g. the discharge becomes more stable.

  7. NASA Laboratory Astrophysics Workshop 2006 Introductory Remarks

    Science.gov (United States)

    Hasan, Hashima

    2006-01-01

    NASA Laboratory Astrophysics Workshop 2006, is the fourth in a series of workshops held at four year intervals, to assess the laboratory needs of NASA's astrophysics missions - past, current and future. Investigators who need laboratory data to interpret their observations from space missions, theorists and modelers, experimentalists who produce the data, and scientists who compile databases have an opportunity to exchange ideas and understand each other's needs and limitations. The multi-wavelength character of these workshops allows cross-fertilization of ideas, raises awareness in the scientific community of the rapid advances in other fields, and the challenges it faces in prioritizing its laboratory needs in a tight budget environment. Currently, we are in the golden age of Space Astronomy, with three of NASA s Great Observatories, Hubble Space Telescope (HST), Chandra X-Ray Observatory (CXO), and Spitzer Space Telescope (SST), in operation and providing astronomers and opportunity to perform synergistic observations. In addition, the Far Ultraviolet Spectroscopic Explorer (FUSE), XMM-Newton, HETE-2, Galaxy Evolution Explorer (GALEX), INTEGRAL and Wilkinson Microwave Anisotropy Probe (WMAP), are operating in an extended phase, while Swift and Suzaku are in their prime phase of operations. The wealth of data from these missions is stretching the Laboratory Astrophysics program to its limits. Missions in the future, which also need such data include the James Webb Space Telescope (JWST), Space Interferometry Mission (SIM), Constellation-X (Con-X), Herschel, and Planck. The interpretation of spectroscopic data from these missions requires knowledge of atomic and molecular parameters such as transition probabilities, f-values, oscillator strengths, excitation cross sections, collision strengths, which have either to be measured in the laboratory by simulating space plasma and interactions therein, or by theoretical calculations and modeling. Once the laboratory

  8. Space and Astrophysical Plasmas : Space and astrophysical plasmas: Pervasive problems

    Indian Academy of Sciences (India)

    Chanchal Uberoi

    2000-11-01

    The observations and measurements given by Earth orbiting satellites, deep space probes, sub-orbital systems and orbiting astronomical observatories point out that there are important physical processes which are responsible for a wide variety of phenomena in solar-terrestrial, solar-system and astrophysical plasmas. In this review these topics are exemplified both from an observational and a theoretical point of view.

  9. Hydrodynamic Instability, Integrated Code, Laboratory Astrophysics, and Astrophysics

    Science.gov (United States)

    Takabe, Hideaki

    2016-10-01

    This is an article for the memorial lecture of Edward Teller Medal and is presented as memorial lecture at the IFSA03 conference held on September 12th, 2003, at Monterey, CA. The author focuses on his main contributions to fusion science and its extension to astrophysics in the field of theory and computation by picking up five topics. The first one is the anomalous resisitivity to hot electrons penetrating over-dense region through the ion wave turbulence driven by the return current compensating the current flow by the hot electrons. It is concluded that almost the same value of potential as the average kinetic energy of the hot electrons is realized to prevent the penetration of the hot electrons. The second is the ablative stabilization of Rayleigh-Taylor instability at ablation front and its dispersion relation so-called Takabe formula. This formula gave a principal guideline for stable target design. The author has developed an integrated code ILESTA (ID & 2D) for analyses and design of laser produced plasma including implosion dynamics. It is also applied to design high gain targets. The third is the development of the integrated code ILESTA. The forth is on Laboratory Astrophysics with intense lasers. This consists of two parts; one is review on its historical background and the other is on how we relate laser plasma to wide-ranging astrophysics and the purposes for promoting such research. In relation to one purpose, I gave a comment on anomalous transport of relativistic electrons in Fast Ignition laser fusion scheme. Finally, I briefly summarize recent activity in relation to application of the author's experience to the development of an integrated code for studying extreme phenomena in astrophysics.

  10. A high energy photon polarimeter for astrophysics

    CERN Document Server

    Eingorn, Maxim; Vlahovic, Branislav; Wojtsekhowski, Bogdan; Urciuoli, Guido Maria; De Persio, Fulvio; Meddi, Franco

    2015-01-01

    A high-energy photon polarimeter for astrophysics studies in the energy range from 20 MeV to 1000 MeV is considered. The proposed concept uses a stack of silicon micro-strip detectors where they play the roles of both a converter and a tracker. The purpose of this paper is to outline the parameters of such a polarimeter and to estimate the productivity of measurements. Our study supported by a Monte Carlo simulation shows that with a one-year observation period the polarimeter will provide 5.5 % accuracy of the polarization degree for a photon energy of 100 MeV, which would be a significant advance relative to the currently explored energy range of a few MeV. The proposed polarimeter design could easily be adjusted to the specific photon energy range to maximize efficiency if needed.

  11. Astrophysical limits on light NMSSM neutralinos

    CERN Document Server

    Vasquez, Daniel Albornoz; Boehm, Celine

    2011-01-01

    It was recently shown that light LSP neutralinos could be found in the framework of the NMSSM. These candidates would escape known Particle Physics constraints even though they are relatively light. We now investigate the astrophysical limits which can be set on these particles. We show, in particular, that the FERMI observation of dwarf spheroidal galaxies enable to constrain the parameter space associated with these candidates and the expected radio emission in the inner Milky Way should be significant. Combined with the XENON100 experimental limits, our results illustrate the complementarity between direct and indirect searches for dark matter. Yet, our findings also suggest that probing light neutralinos in the NMSSM scenario will be very difficult because the sensitivity of both dark matter direct and indirect detection experiments would have to be improved by at least six order of magnitude compared to present values in order to explore the entire parameter space. Finally, we show that the parameter spa...

  12. Similarity Properties and Scaling Laws of Radiating Fluids in Laboratory Astrophysics Context

    CERN Document Server

    Falize, Emeric; Michaut, Claire

    2009-01-01

    The spectacular recent development of powerful facilities allows the astrophysical community to explore, in laboratory, astrophysical phenomena where radiation and matter are strongly coupled. The astrophysical relevance of these experiments can be checked from scaling laws, provided the physical system under study satis?es similarity properties. In this paper we derive the scaling laws, with Lie group formalism, for di?erent radiating ?uids regimes which are relevant for laboratory astrophysics in particular and more widely for High-Energy-Density Physics. In order to illustrate how to use these results, we examine the reproduction of the Taylor-Sedov blast wave and the accreted column in magnetic cataclysmic variables. Although all discussions are set in an astrophysical context, these results can easily be transcribed in di?erent High-Energy-Density Physics domains such as the target design in inertial fusion.

  13. Astrophysical Applications of Fractional Calculus

    Science.gov (United States)

    Stanislavsky, Aleksander A.

    The paradigm of fractional calculus occupies an important place for the macroscopic description of subdiffusion. Its advance in theoretical astrophysics is expected to be very attractive too. In this report we discuss a recent development of the idea to some astrophysical problems. One of them is connected with a random migration of bright points associated with magnetic fields at the solar photosphere. The transport of the bright points has subdiffusive features that require the fractional generalization of the Leighton's model. Another problem is related to the angular distribution of radio beams, being propagated through a medium with random inhomogeneities. The peculiarity of this medium is that radio beams are trapped because of random wave localization. This idea can be useful for the diagnostics of interplanetary and interstellar turbulent media.

  14. Focusing Telescopes in Nuclear Astrophysics

    CERN Document Server

    Ballmoos, Peter von

    2007-01-01

    This volume is the first of its kind on focusing gamma-ray telescopes. Forty-eight refereed papers provide a comprehensive overview of the scientific potential and technical challenges of this nascent tool for nuclear astrophysics. The book features articles dealing with pivotal technologies such as grazing incident mirrors, multilayer coatings, Laue- and Fresnel-lenses - and even an optic using the curvature of space-time. The volume also presents an overview of detectors matching the ambitious objectives of gamma ray optics, and facilities for operating such systems on the ground and in space. The extraordinary scientific potential of focusing gamma-ray telescopes for the study of the most powerful sources and the most violent events in the Universe is emphasized in a series of introductory articles. Practicing professionals, and students interested in experimental high-energy astrophysics, will find this book a useful reference

  15. Large Eddy Simulations in Astrophysics

    CERN Document Server

    Schmidt, Wolfram

    2014-01-01

    In this review, the methodology of large eddy simulations (LES) is introduced and applications in astrophysics are discussed. As theoretical framework, the scale decomposition of the dynamical equations for neutral fluids by means of spatial filtering is explained. For cosmological applications, the filtered equations in comoving coordinates are also presented. To obtain a closed set of equations that can be evolved in LES, several subgrid scale models for the interactions between numerically resolved and unresolved scales are discussed, in particular the subgrid scale turbulence energy equation model. It is then shown how model coefficients can be calculated, either by dynamical procedures or, a priori, from high-resolution data. For astrophysical applications, adaptive mesh refinement is often indispensable. It is shown that the subgrid scale turbulence energy model allows for a particularly elegant and physically well motivated way of preserving momentum and energy conservation in AMR simulations. Moreover...

  16. Particle Acceleration in Astrophysical Sources

    CERN Document Server

    Amato, Elena

    2015-01-01

    Astrophysical sources are extremely efficient accelerators. Some sources emit photons up to multi-TeV energies, a signature of the presence, within them, of particles with energies much higher than those achievable with the largest accelerators on Earth. Even more compelling evidence comes from the study of Cosmic Rays, charged relativistic particles that reach the Earth with incredibly high energies: at the highest energy end of their spectrum, these subatomic particles are carrying a macroscopic energy, up to a few Joules. Here I will address the best candidate sources and mechanisms as cosmic particle accelerators. I will mainly focus on Galactic sources such as Supernova Remnants and Pulsar Wind Nebulae, which being close and bright, are the best studied among astrophysical accelerators. These sources are held responsible for most of the energy that is put in relativistic particles in the Universe, but they are not thought to accelerate particles up to the highest individual energies, $\\approx 10^{20}$ eV...

  17. Astrophysical Mechanisms for Pulsar Spindown

    OpenAIRE

    Addison, Eric

    2011-01-01

    Pulsars are astrophysical sources of pulsed electromagnetic radiation. The pulses have a variety of shapes in the time-domain, and the pulse energy generally peaks in the radio spectrum. The accepted models theorize that pulsars are rapidly rotating neutron stars with strong dipolar magnetic fields. Current models predict that rotational kinetic energy is extracted from the pulsar in the form of electromagnetic and gravitational radiation, causing it to slowly lose rotational speed, or “spin ...

  18. Astrophysical aspects of Weyl gravity

    Science.gov (United States)

    Kazanas, Demosthenes

    1991-01-01

    This paper discusses the astrophysical implications and applications of Weyl gravity, which is the theory resulting from the unique action allowed under the principle of local scale invariance in Einstein gravity. These applications include galactic dynamics, the mass-radius relation, the cosmological constant, and the 'Modified Newtonian Dynamics' proposed by Milgrom (1983). The relation of Weyl gravity to other scale-invariant theories is addressed.

  19. High energy astrophysics an introduction

    CERN Document Server

    Courvoisier, Thierry J -L

    2013-01-01

    High-energy astrophysics has unveiled a Universe very different from that only known from optical observations. It has revealed many types of objects in which typical variability timescales are as short as years, months, days, and hours (in quasars, X-ray binaries, and other objects), and even down to milli-seconds in gamma ray bursts. The sources of energy that are encountered are only very seldom nuclear fusion, and most of the time gravitation, a paradox when one thinks that gravitation is, by many orders of magnitude, the weakest of the fundamental interactions. The understanding of these objects' physical conditions and the processes revealed by high-energy astrophysics in the last decades is nowadays part of astrophysicists' culture, even of those active in other domains of astronomy. This book evolved from lectures given to master and PhD students at the University of Geneva since the early 1990s. It aims at providing astronomers and physicists intending to be active in high-energy astrophysics a broad...

  20. Astrophysics with Microarcsecond Accuracy Astrometry

    Science.gov (United States)

    Unwin, Stephen C.

    2008-01-01

    Space-based astrometry promises to provide a powerful new tool for astrophysics. At a precision level of a few microarcsonds, a wide range of phenomena are opened up for study. In this paper we discuss the capabilities of the SIM Lite mission, the first space-based long-baseline optical interferometer, which will deliver parallaxes to 4 microarcsec. A companion paper in this volume will cover the development and operation of this instrument. At the level that SIM Lite will reach, better than 1 microarcsec in a single measurement, planets as small as one Earth can be detected around many dozen of the nearest stars. Not only can planet masses be definitely measured, but also the full orbital parameters determined, allowing study of system stability in multiple planet systems. This capability to survey our nearby stellar neighbors for terrestrial planets will be a unique contribution to our understanding of the local universe. SIM Lite will be able to tackle a wide range of interesting problems in stellar and Galactic astrophysics. By tracing the motions of stars in dwarf spheroidal galaxies orbiting our Milky Way, SIM Lite will probe the shape of the galactic potential history of the formation of the galaxy, and the nature of dark matter. Because it is flexibly scheduled, the instrument can dwell on faint targets, maintaining its full accuracy on objects as faint as V=19. This paper is a brief survey of the diverse problems in modern astrophysics that SIM Lite will be able to address.

  1. Einstein Toolkit for Relativistic Astrophysics

    Science.gov (United States)

    Collaborative Effort

    2011-02-01

    The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems. Such systems include gravitational wave space-times, collisions of compact objects such as black holes or neutron stars, accretion onto compact objects, core collapse supernovae and Gamma-Ray Bursts. The Einstein Toolkit builds on numerous software efforts in the numerical relativity community including CactusEinstein, Whisky, and Carpet. The Einstein Toolkit currently uses the Cactus Framework as the underlying computational infrastructure that provides large-scale parallelization, general computational components, and a model for collaborative, portable code development.

  2. Astrophysics Source Code Library Enhancements

    CERN Document Server

    Hanisch, Robert J; Berriman, G Bruce; DuPrie, Kimberly; Mink, Jessica; Nemiroff, Robert J; Schmidt, Judy; Shamir, Lior; Shortridge, Keith; Taylor, Mark; Teuben, Peter J; Wallin, John

    2014-01-01

    The Astrophysics Source Code Library (ASCL; ascl.net) is a free online registry of codes used in astronomy research; it currently contains over 900 codes and is indexed by ADS. The ASCL has recently moved a new infrastructure into production. The new site provides a true database for the code entries and integrates the WordPress news and information pages and the discussion forum into one site. Previous capabilities are retained and permalinks to ascl.net continue to work. This improvement offers more functionality and flexibility than the previous site, is easier to maintain, and offers new possibilities for collaboration. This presentation covers these recent changes to the ASCL.

  3. Laboratory Studies of Astrophysical Jets

    CERN Document Server

    Ciardi, Andrea

    2009-01-01

    Jets and outflows produced during star-formation are observed on many scales: from the "micro-jets" extending a few hundred Astronomical Units to the "super-jets" propagating to parsecs distances. Recently, a new "class" of short-lived (hundreds of nano-seconds) centimetre-long jets has emerged in the laboratory as a complementary tool to study these complex astrophysical flows. Here I will discuss and review the recent work done on "simulating" protostellar jets in the laboratory using z-pinch machines.

  4. Astrophysics and Cosmology: International Partnerships

    Science.gov (United States)

    Blandford, Roger

    2016-03-01

    Most large projects in astrophysics and cosmology are international. This raises many challenges including: --Aligning the sequence of: proposal, planning, selection, funding, construction, deployment, operation, data mining in different countries --Managing to minimize cost growth through reconciling different practices --Communicating at all levels to ensure a successful outcome --Stabilizing long term career opportunities. There has been considerable progress in confronting these challenges. Lessons learned from past collaborations are influencing current facilities but much remains to be done if we are to optimize the scientific and public return on the expenditure of financial and human resources.

  5. Astrophysical constraints on dark energy

    Science.gov (United States)

    Ho, Chiu Man; Hsu, Stephen D. H.

    2016-02-01

    Dark energy (i.e., a cosmological constant) leads, in the Newtonian approximation, to a repulsive force which grows linearly with distance and which can have astrophysical consequences. For example, the dark energy force overcomes the gravitational attraction from an isolated object (e.g., dwarf galaxy) of mass 107M⊙ at a distance of 23 kpc. Observable velocities of bound satellites (rotation curves) could be significantly affected, and therefore used to measure or constrain the dark energy density. Here, isolated means that the gravitational effect of large nearby galaxies (specifically, of their dark matter halos) is negligible; examples of isolated dwarf galaxies include Antlia or DDO 190.

  6. Astrophysics on the lab bench

    Science.gov (United States)

    Hughes, Stephen W.

    2010-05-01

    In this article some basic laboratory bench experiments are described that are useful for teaching high school students some of the basic principles of stellar astrophysics. For example, in one experiment, students slam a plastic water-filled bottle down onto a bench, ejecting water towards the ceiling, illustrating the physics associated with a type II supernova explosion. In another experiment, students roll marbles up and down a double ramp in an attempt to get a marble to enter a tube halfway up the slope, which illustrates quantum tunnelling in stellar cores. The experiments are reasonably low cost to either purchase or manufacture.

  7. Solar astrophysics. 3. rev. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Foukal, Peter V. [CRI, Nahant, MA (United States)

    2013-06-01

    This third, revised edition describes our current understanding of the sun - from its deepest interior, via the layers of the directly observable atmosphere to the solar wind, right up to its farthest extension into interstellar space. It includes a comprehensive account of the history of solar astrophysics, and the evolution of solar instruments. This account now includes the most up- to-date implementation of modern solar instruments in facilities on the ground and in space. The revised book now also provides an overview of recent results on ''space weather'' and on sun-climate relations, both of which are fields of increasing societal importance.

  8. Multimessenger Astronomy and Astrophysics Synergies

    CERN Document Server

    van Putten, Maurice H P M

    2012-01-01

    A budget neutral strategy is proposed for NSF to lead the implementation of multimessenger astronomy and astrophysics, as outlined in the Astro2010 Decadal Survey. The emerging capabilities for simultaneous measurements of physical and astronomical data through the different windows of electromagnetic, hadronic and gravitational radiation processes call for a vigorous pursuit of new synergies. The proposed approach is aimed at the formation of new collaborations and multimessenger data-analysis, to transcend the scientific inquiries made within a single window of observations. In view of budgetary constraints, we propose to include the multimessenger dimension in the ranking of proposals submitted under existing NSF programs.

  9. Astrophysical Observations: Lensing and Eclipsing Einstein's Theories

    OpenAIRE

    Bennett, Charles L.

    2005-01-01

    Albert Einstein postulated the equivalence of energy and mass, developed the theory of special relativity, explained the photoelectric effect, and described Brownian motion in five papers, all published in 1905, 100 years ago. With these papers, Einstein provided the framework for understanding modern astrophysical phenomena. Conversely, astrophysical observations provide one of the most effective means for testing Einstein's theories. Here, I review astrophysical advances precipitated by Ein...

  10. Nuclear physics in astrophysics. Part 2. Abstracts

    International Nuclear Information System (INIS)

    The proceedings of the 20. International Nuclear Physics Divisional Conference of the European Physical Society covers a wide range of topics in nuclear astrophysics. The topics addressed are big bang nucleosynthesis, stellar nucleosynthesis, measurements and nuclear data for astrophysics, nuclear structure far from stability, neutrino physics, and rare-ion-beam facilities and experiments. The perspectives of nuclear physics and astrophysics are also overviewed. 77 items are indexed separately for the INIS database. (K.A.)

  11. Investigation of plasma dynamics and emission in a dense plasma focus

    International Nuclear Information System (INIS)

    The heating mechanism of plasma in a plasma focus discharge is investigated through correlation between plasma dynamics and emission of neutrons, X-rays and charged particles. Various measurements are carried out by using a Mach-Zehnder interferometer, a time resolved soft X-ray camera, and a Thomson parabola ion analyser. High energy deuterons are measured by nuclear activation techniques. The target used in the measurement, consisting of two semi-circles (aluminium and carbon), determines the mean energy of the deuterons, from the 13N/28Al ratio. The ion temperature and the kinetic energy, from the D-D/D-3He yield ratio, are obtained by using an equimolecular D2-3He mixture. The neutron emission region and the neutron intensity distribution are determined by using a neutron pinhole camera. The experimental results show that the plasma emits soft X-rays in three successive phases: the maximum compression, plasma disruption and decay phases. Immediately after disruption, emission of neutrons, soft X-rays and charged particles is observed. The energy distribution of the deuteron beam produced by the plasma focus is obtained. (author)

  12. Explosive-Emission Plasma Dynamics in Ion Diode in Double-Pulse Mode

    International Nuclear Information System (INIS)

    The results of an experimental investigation of explosive-emission plasma dynamics in an ion diode with self-magnetic insulation are presented. The investigations were accomplished at the TEMP-4M accelerator set in a mode of double pulse formation. Plasma behaviour in the anode-cathode gap was analyzed according to both the current-voltage characteristics of the diode (time resolution of 0.5 ns) and thermal imprints on a target (spatial resolution of 0.8 mm). It was shown that when plasma formation at the potential electrode was complete, and up until the second (positive) pulse, the explosive-emission plasma expanded across the anode-cathode gap with a speed of 1.3±0.2 cm/μs. After the voltage polarity at the potential electrode was reversed (second pulse), the plasma erosion in the anode-cathode gap (similar to the effect of a plasma opening switch) occurred. During the generation of an ion beam the size of the anode-cathode gap spacing was determined by the thickness of the plasma layer on the potential electrode and the layer thickness of the electrons drifting along the grounded electrode. (15th asian conference on electrical discharge)

  13. Progresses of Laboratory Astrophysics in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gang; ZHANG Jie

    2011-01-01

    The exciting discoveries in astronomy such as the accelerating expansion of the universe, the atmospheric composition of exoplanets, and the abundance trends of various types of stars rely upon advances in laboratory astrophysics. These new discoveries have occurred along with dramatic improvements in measurements by ground- based and space-based instruments of astrophysical processes under extreme physical conditions. Laboratory astrophysics is an exciting and rapidly growing field emerging since the beginning of this century, which covers a wide range of scientific areas such as astrophysics,

  14. High Energy Astrophysics Science Archive Research Center

    Data.gov (United States)

    National Aeronautics and Space Administration — The High Energy Astrophysics Science Archive Research Center (HEASARC) is the primary archive for NASA missions dealing with extremely energetic phenomena, from...

  15. High-Energy Astrophysics: An Overview

    Science.gov (United States)

    Fishman, Gerald J.

    2007-01-01

    High-energy astrophysics is the study of objects and phenomena in space with energy densities much greater than that found in normal stars and galaxies. These include black holes, neutron stars, cosmic rays, hypernovae and gamma-ray bursts. A history and an overview of high-energy astrophysics will be presented, including a description of the objects that are observed. Observing techniques, space-borne missions in high-energy astrophysics and some recent discoveries will also be described. Several entirely new types of astronomy are being employed in high-energy astrophysics. These will be briefly described, along with some NASA missions currently under development.

  16. Analytic studies in nuclear astrophysics

    Science.gov (United States)

    Pizzochero, Pierre

    Five studies are presented in nuclear astrophysics, which deal with different stages of stellar evolution and which use analytic techniques as opposed to numerical ones. Two problems are described in neutrino astrophysics: the solar-neutrino puzzle is analyzed in the framework of the MSW mechanism for the enhancement of neutrino oscillations in matter; and the cooling of neutron stars is studied by calculating the neutrino emissivity from strangeness condensation. Radiative transfer is then examined as applied to SN1987A: its early spectrum and bolometric corrections are calculated by developing an analytic model which can describe both the extended nature of the envelope and the non-LTE state of the radiation field in the scattering-dominated early atmosphere; and a model-independent relation is derived between mass and kinetic energy for the hydrogen envelope of SN1987A, using only direct observations of its luminosity and photospheric velocity. Finally, an analytic approach is presented to relate the softness of the EOS of dense nuclear matter in the core of a supernova, the hydrostatic structure of such core and the initial strength of the shock wave.

  17. Did high energy astrophysical sources contribute to Martian atmospheric loss?

    CERN Document Server

    Atri, Dimitra

    2016-01-01

    Mars is believed to have had a substantial atmosphere in the past. Atmospheric loss led to depressurization and cooling, and is thought to be the primary driving force responsible for the loss of liquid water from its surface. Recently, MAVEN observations have provided new insight into the physics of atmospheric loss induced by ICMEs and solar wind interacting with the Martian atmosphere. In addition to solar radiation, it is likely that its atmosphere has been exposed to radiation bursts from high-energy astrophysical sources which become highly probable on timescales of ~Gy and beyond. These sources are capable of significantly enhancing the rates of photoionization and charged particle-induced ionization in the upper atmosphere. Here, we explore the possibility of damage from Galactic Gamma Ray Bursts, nearby supernovae, encounter with dense interstellar clouds and extreme solar events. We use Monte Carlo simulations to model the interaction of charged particles and photons from astrophysical sources in th...

  18. Sunfall: a collaborative visual analytics system for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl; Thomas, Rollin C.

    2008-07-07

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

  19. Nuclear Astrophysics with the Trojan Horse Method

    Science.gov (United States)

    Tumino, A.; Spitaleri, C.; Lamia, L.; Pizzone, R. G.; Cherubini, S.; Gulino, M.; La Cognata, M.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Spartá, R.

    2016-01-01

    The Trojan Horse Method (THM) represents the indirect path to determine the bare nucleus astrophysical S(E) factor for reactions between charged particles at astrophysical energies. This is done by measuring the quasi free cross section of a suitable three body process. The basic features of the THM will be presented together with some applications to demonstrate its practical use.

  20. Proceedings of the NASA Laboratory Astrophysics Workshop

    Science.gov (United States)

    Weck, Phillippe F. (Editor); Kwong, Victor H. S. (Editor); Salama, Farid (Editor)

    2006-01-01

    This report is a collection of papers presented at the 2006 NASA Workshop on Laboratory Astrophysics held in the University of Nevada, Las Vegas (UNLV) from February 14 to 16, 2006. This workshop brings together producers and users of laboratory astrophysics data so that they can understand each other's needs and limitations in the context of the needs for NASA's missions. The last NASA-sponsored workshop was held in 2002 at Ames Research Center. Recent related meetings include the Topical Session at the AAS meeting and the European workshop at Pillnitz, Germany, both of which were held in June 2005. The former showcased the importance of laboratory astrophysics to the community at large, while the European workshop highlighted a multi-laboratory approach to providing the needed data. The 2006 NASA Workshop on Laboratory Astrophysics, sponsored by the NASA Astrophysics Division, focused on the current status of the field and its relevance to NASA. This workshop attracted 105 participants and 82 papers of which 19 were invited. A White Paper identifying the key issues in laboratory astrophysics during the break-out sessions was prepared by the Scientific Organizing Committee, and has been forwarded to the Universe Working Group (UWG) at NASA Headquarters. This White Paper, which represented the collective inputs and opinions from experts and stakeholders in the field of astrophysics, should serve as the working document for the future development of NASA's R&A program in laboratory astrophysics.

  1. Flexible, Mastery-Oriented Astrophysics Sequence.

    Science.gov (United States)

    Zeilik, Michael, II

    1981-01-01

    Describes the implementation and impact of a two-semester mastery-oriented astrophysics sequence for upper-level physics/astrophysics majors designed to handle flexibly a wide range of student backgrounds. A Personalized System of Instruction (PSI) format was used fostering frequent student-instructor interaction and role-modeling behavior in…

  2. Astrophysics at the Highest Energy Frontiers

    OpenAIRE

    Stecker, F. W.

    2002-01-01

    I discuss recent advances being made in the physics and astrophysics of cosmic rays and cosmic gamma-rays at the highest observed energies as well as the related physics and astrophysics of very high energy cosmic neutrinos. I also discuss the connections between these topics.

  3. Astrophysics with small satellites in Scandinavia

    DEFF Research Database (Denmark)

    Lund, Niels

    2003-01-01

    The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.......The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved....

  4. Focusing telescopes in nuclear astrophysics

    International Nuclear Information System (INIS)

    The objective of this workshop is to consider the next generation of instrumentation to be required within the domain of nuclear astrophysics. A small, but growing community has been pursuing various techniques for the focusing of hard X-rays and gamma-rays with the aim of achieving a factor of up to 100 improvement in sensitivity over present technologies. Balloon flight tests of both multilayer mirrors and a Laue lens have been performed and ideas abound. At present, implementation scenarios for space missions are being studied at Esa, CNES, and elsewhere. The workshop will provide a first opportunity for this new community to meet, exchange technological know-how, discuss scientific objectives and synergies, and consolidate implementation approaches within National and European Space Science programs. This document gathers the slides of all the presentations

  5. Focusing telescopes in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Von Ballmoos, P.; Knodlseder, R.; Sazonov, S.; Griffiths, R.; Bastie, P.; Halloin, H.; Pareschi, G.; Ramsey, B.; Jensen, C.; Buis, E.J.; Ulmer, M.; Giommi, P.; Colafrancesco, S.; Comastri, A.; Barret, D.; Leising, M.; Hernanz, M.; Smith, D.; Abrosimov, N.; Smither, B.; Ubertini, P.; Olive, J.F.; Lund, N.; Pisa, A.; Courtois, P.; Roa, D.; Harrison, F.; Pareschi, G.; Frontera, F.; Von Ballmoos, P.; Barriere, N.; Rando, N.; Borde, J.; Hinglais, E.; Cledassou, R.; Duchon, P.; Sghedoni, M.; Huet, B.; Takahashi, T.; Caroli, E.; Quadrinin, L.; Buis, E.J.; Skinner, G.; Krizmanic, J.; Pareschi, G.; Loffredo, G.; Wunderer, C.; Weidenspointner, G.; Wunderer, C.; Koechlin, L.; Bignami, G.; Von Ballmoos, P.; Tueller, J.; Andritschke, T.; Laurens, A.; Evrard, J

    2005-07-01

    The objective of this workshop is to consider the next generation of instrumentation to be required within the domain of nuclear astrophysics. A small, but growing community has been pursuing various techniques for the focusing of hard X-rays and gamma-rays with the aim of achieving a factor of up to 100 improvement in sensitivity over present technologies. Balloon flight tests of both multilayer mirrors and a Laue lens have been performed and ideas abound. At present, implementation scenarios for space missions are being studied at Esa, CNES, and elsewhere. The workshop will provide a first opportunity for this new community to meet, exchange technological know-how, discuss scientific objectives and synergies, and consolidate implementation approaches within National and European Space Science programs. This document gathers the slides of all the presentations.

  6. Astrophysical Conditions for Planetary Habitability

    CERN Document Server

    Guedel, M; Erkaev, N; Kasting, J; Khodachenko, M; Lammer, H; Pilat-Lohinger, E; Rauer, H; Ribas, I; Wood, B E

    2014-01-01

    With the discovery of hundreds of exoplanets and a potentially huge number of Earth-like planets waiting to be discovered, the conditions for their habitability have become a focal point in exoplanetary research. The classical picture of habitable zones primarily relies on the stellar flux allowing liquid water to exist on the surface of an Earth-like planet with a suitable atmosphere. However, numerous further stellar and planetary properties constrain habitability. Apart from "geophysical" processes depending on the internal structure and composition of a planet, a complex array of astrophysical factors additionally determine habitability. Among these, variable stellar UV, EUV, and X-ray radiation, stellar and interplanetary magnetic fields, ionized winds, and energetic particles control the constitution of upper planetary atmospheres and their physical and chemical evolution. Short- and long-term stellar variability necessitates full time-dependent studies to understand planetary habitability at any point ...

  7. Dust alignment in astrophysical environments

    Science.gov (United States)

    Lazarian, Alex; Thiem Hoang, Chi

    Dust is known to be aligned in interstellar medium and the arising polarization is extensively used to trace magnetic fields. What process aligns dust grains was one of the most long-standing problems of astrophysics in spite of the persistent efforts to solve it. For years the Davis-Greenstein paramagnetic alignment was the primary candidate for explaining grain alignment. However, the situation is different now and the most promising mechanism is associated with radiative torques (RATs) acting on irregular grains. I shall present the analytical theory of RAT alignment, discuss the observational tests that support this theory. I shall also discuss in what situations we expect to see the dominance of paramagnetic alignment.

  8. Transfer reactions in nuclear astrophysics

    Science.gov (United States)

    Bardayan, D. W.

    2016-08-01

    To a high degree many aspects of the large-scale behavior of objects in the Universe are governed by the underlying nuclear physics. In fact the shell structure of nuclear physics is directly imprinted into the chemical abundances of the elements. The tranquility of the night sky is a direct result of the relatively slow rate of nuclear reactions that control and determines a star’s fate. Understanding the nuclear structure and reaction rates between nuclei is vital to understanding our Universe. Nuclear-transfer reactions make accessible a wealth of knowledge from which we can extract much of the required nuclear physics information. A review of transfer reactions for nuclear astrophysics is presented with an emphasis on the experimental challenges and opportunities for future development.

  9. Large-Scale Astrophysical Visualization on Smartphones

    Science.gov (United States)

    Becciani, U.; Massimino, P.; Costa, A.; Gheller, C.; Grillo, A.; Krokos, M.; Petta, C.

    2011-07-01

    Nowadays digital sky surveys and long-duration, high-resolution numerical simulations using high performance computing and grid systems produce multidimensional astrophysical datasets in the order of several Petabytes. Sharing visualizations of such datasets within communities and collaborating research groups is of paramount importance for disseminating results and advancing astrophysical research. Moreover educational and public outreach programs can benefit greatly from novel ways of presenting these datasets by promoting understanding of complex astrophysical processes, e.g., formation of stars and galaxies. We have previously developed VisIVO Server, a grid-enabled platform for high-performance large-scale astrophysical visualization. This article reviews the latest developments on VisIVO Web, a custom designed web portal wrapped around VisIVO Server, then introduces VisIVO Smartphone, a gateway connecting VisIVO Web and data repositories for mobile astrophysical visualization. We discuss current work and summarize future developments.

  10. Graduate Program in Astrophysics in Split

    CERN Document Server

    Krajnovic, D

    2006-01-01

    Beginning in autumn 2008 the first generation of astronomy master students will start a 2 year course in Astrophysics offered by the Physics department of the University of Split, Croatia (http://fizika.pmfst.hr/astro/english/index.html). This unique master course in South-Eastern Europe, following the Bologna convention and given by astronomers from international institutions, offers a series of comprehensive lectures designed to greatly enhance students' knowledge and skills in astrophysics, and prepare them for a scientific career. An equally important aim of the course is to recognise the areas in which astronomy and astrophysics can serve as a national asset and to use them to prepare young people for real life challenges, enabling graduates to enter the modern society as a skilled and attractive work-force. In this contribution, I present an example of a successful organisation of international astrophysics studies in a developing country, which aims to become a leading graduate program in astrophysics ...

  11. A Vigorous Explorer Program

    CERN Document Server

    Elvis, Martin; Brissenden, Roger; Chakrabarti, Supriya; Cherry, Michael; Devlin, Mark; Edelstein, Jerry; Eisenhardt, Peter; Feldman, Paul; Ford, Holland; Gehrels, Neil; Golub, Leon; Marshall, Herman; Martin, Christopher; Mather, John; McCandliss, Stephan; McConnell, Mark; McDowell, Jonathan; Meier, David; Millan, Robyn; Mitchell, John; Moos, Warren; Murray, Steven S; Nousek, John; Oegerle, William; Ramsey, Brian; Green, James; Grindlay, Jonathan; Kaaret, Philip; Kaiser, Mary Elizabeth; Kaltenegger, Lisa; Kasper, Justin; Krolik, Julian; Kruk, Jeffrey W; Latham, David; MacKenty, John; Mainzer, Amanda; Ricker, George; Rinehart, Stephen; Romaine, Suzanne; Scowen, Paul; Silver, Eric; Sonneborn, George; Stern, Daniel; Swain, Mark; Swank, Jean; Traub, Wesley; Weisskopf, Martin; Werner, Michael; Wright, Edward

    2009-01-01

    Explorers have made breakthroughs in many fields of astrophysics. The science from both these missions contributed to three Nobel Prizes - Giacconi (2002), Mather, and Smoot (2006). Explorers have: marked the definitive beginning of precision cosmology, discovered that short gamma-ray bursts are caused by compact star mergers and have measured metalicity to redshifts z>6. NASA Explorers do cutting-edge science that cannot be done by facility-class instruments. The Explorer program provides a rapid response to changing science and technology, to enable cutting-edge science at moderate cost. Explorers also enable innovation, and engage & train scientists, managers and engineers, adding human capital to NASA and the nation. The astrophysics Explorer launch rate now being achieved is 1 per 3 years, and budget projections are in the $150M/year range for the next five years. A newly Vigorous Explorer Program should be created to: 1. Reach the long-stated goal of annual astrophysics launches; 2. Find additional ...

  12. PREFACE: International Conference on Particle Physics and Astrophysics (ICPPA-2015)

    Science.gov (United States)

    2016-02-01

    , investigation of high energy γ-emission from GRBs and other astrophysical objects including Sun, explore of high energy e-e+ fluxes, research of high energy light nuclei fluxes. Several talks concern the cosmic ray physics with high energy muons in large volume detectors - IceCube, NEVOD are among them. Also γ-quanta and charged particles generation in astrophysical sources and planets magnetospheres were discussed in the frameworks of Cosmic Rays subsection. Cosmological problems such as an origin and features of the dark matter, space reionization, smallness of the cosmological constant and black hole origin are discussed at the theoretical section of the conference. Special workshops are devoted to NEVOD experiment, Pamela Experiment, SiPM and Electronics.

  13. Technological challenges on the path to discovery in astrophysics

    Science.gov (United States)

    Perez, Mario R.

    2016-05-01

    Over the next decade, NASA's Astrophysics Division expects to undertake robotic or unmanned space flight missions that will explore the nature of the universe at its largest scales, its earliest moments, and its most extreme conditions. Current innovative and maturation technology programs are being conducted by NASA's Astrophysics Division to fill the technology gaps identified by the community. One of these efforts was to establish the Strategic Astrophysics Technology (SAT) program to support the maturation of key technologies. In this paper, these technology programs are described; in particular the SAT program will be presented describing the process to establish priorities, the technology management components, and the efforts to move these technologies into mission concepts and flight missions. The technology roadmap for a large mission concept such as ATLAST is presented as an example of the technology gaps derived and identified from these analyses, which could focus future efforts and investment priorities. Finally, the NASA preparation for the next decade, which will study and mature four large mission concepts, is briefly outlined.

  14. Exploring the Tera - universe with the LHC, Astrophysics and Cosmology

    OpenAIRE

    Sathnur, Ashwini

    2016-01-01

    Study of Dark matter and dark energy from the analysis of LHC experiment data. Arriving at the quantity of dark matter. Relation between the dark matter and the tera universe. Also deriving the energy scales of the dark matter from the LHC experimental derived data sets and displaying the mathematical formulas for the dark energy’s quantity. Upon finding the contents of the dark matter, deriving its impacts on human lives. Also deriving the relation of the dark ma...

  15. NASA Announces 2009 Astronomy and Astrophysics Fellows

    Science.gov (United States)

    2009-02-01

    WASHINGTON -- NASA has selected fellows in three areas of astronomy and astrophysics for its Einstein, Hubble, and Sagan Fellowships. The recipients of this year's post-doctoral fellowships will conduct independent research at institutions around the country. "The new fellows are among the best and brightest young astronomers in the world," said Jon Morse, director of the Astrophysics Division in NASA's Science Mission Directorate in Washington. "They already have contributed significantly to studies of how the universe works, the origin of our cosmos and whether we are alone in the cosmos. The fellowships will serve as a springboard for scientific leadership in the years to come, and as an inspiration for the next generation of students and early career researchers." Each fellowship provides support to the awardees for three years. The fellows may pursue their research at any host university or research center of their choosing in the United States. The new fellows will begin their programs in the fall of 2009. "I cannot tell you how much I am looking forward to spending the next few years conducting research in the U.S., thanks to the fellowships," said Karin Oberg, a graduate student in Leiden, The Netherlands. Oberg will study the evolution of water and ices during star formation when she starts her fellowship at the Smithsonian Astrophysical Observatory in Cambridge, Mass. People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act Cosmic Heavyweights in Free-for-all Galaxies Coming of Age in Cosmic Blobs Cassiopeia A Comes Alive Across Time and Space A diverse group of 32 young scientists will work on a wide variety of projects, such as understanding supernova hydrodynamics, radio transients, neutron stars, galaxy clusters and the intercluster medium, supermassive black holes, their mergers and the associated gravitational waves, dark energy, dark matter and the reionization process. Other research topics include

  16. Plasma Astrophysics, Part I Fundamentals and Practice

    CERN Document Server

    Somov, Boris V

    2012-01-01

    This two-part book is devoted to classic fundamentals and current practices and perspectives of modern plasma astrophysics. This first part uniquely covers all the basic principles and practical tools required for understanding and work in plasma astrophysics. More than 25% of the text is updated from the first edition, including new figures, equations and entire sections on topics such as magnetic reconnection and the Grad-Shafranov equation. The book is aimed at professional researchers in astrophysics, but it will also be useful to graduate students in space sciences, geophysics, applied physics and mathematics, especially those seeking a unified view of plasma physics and fluid mechanics.

  17. Dark matter astrophysical uncertainties and the neutrino floor

    Science.gov (United States)

    O'Hare, Ciaran A. J.

    2016-09-01

    The search for weakly interacting massive particles (WIMPs) by direct detection faces an encroaching background due to coherent neutrino-nucleus scattering. For a given WIMP mass the cross section at which neutrinos constitute a dominant background is dependent on the uncertainty on the flux of each neutrino source, principally from the Sun, supernovae or atmospheric cosmic ray collisions. However there are also considerable uncertainties with regard to the astrophysical ingredients of the predicted WIMP signal. Uncertainties in the velocity of the Sun with respect to the Milky Way dark matter halo, the local density of WIMPs, and the shape of the local WIMP speed distribution all have an effect on the expected event rate in direct detection experiments and hence will change the region of the WIMP parameter space for which neutrinos are a significant background. In this work we extend the neutrino floor calculation to account for the uncertainty in the astrophysics dependence of the WIMP signal. We show the effect of uncertainties on projected discovery limits with an emphasis on low WIMP masses (less than 10 GeV) when solar neutrino backgrounds are most important. We find that accounting for astrophysical uncertainties changes the shape of the neutrino floor as a function of WIMP mass but also causes it to appear at cross sections up to an order of magnitude larger, extremely close to existing experimental limits, indicating that neutrino backgrounds will become an issue sooner than previously thought. We also explore how neutrinos hinder the estimation of WIMP parameters and how astrophysical uncertainties impact the discrimination of WIMPs and neutrinos with the use of their respective time dependencies.

  18. Problem-based learning in astrophysics

    International Nuclear Information System (INIS)

    Problem-based learning (PBL) can be integrated into the curriculum in many different ways. We compare three examples of PBL in undergraduate astrophysics programmes, and discuss the strengths and weaknesses of the various approaches

  19. The molecular astrophysics of stars and galaxies.

    Science.gov (United States)

    Hartquist, T. W.; Williams, D. A.

    This book provides a comprehensive survey of modern molecular astrophysics. It gives an introduction to molecular spectroscopy and then addresses the main areas of current molecular astrophysics, including galaxy formation, star forming regions, mass loss from young as well as highly evolved stars and supernovae, starburst galaxies plus the tori and discs near the central engines of active galactic nuclei. With chapters written by leading experts, the book is unique in giving a detailed view of this wide-ranging subject. It will provide the standard introduction for research students in molecular astrophysics; it will also enable chemists to learn the astrophysics most related to chemistry as well as instruct physicists about the molecular processes most important in astronomy. This volume is dedicated to Alexander Dalgarno.

  20. Cosmological and Astrophysical Neutrino Mass Measurements

    CERN Document Server

    Abazajian, K N; Cooray, A; De Bernardis, F; Dodelson, S; Friedland, A; Fuller, G M; Hannestad, S; Keating, B G; Linder, E V; Lunardini, C; Melchiorri, A; Miquel, R; Pierpaoli, E; Pritchard, J; Serra, P; Takada, M; Wong, Y Y Y

    2011-01-01

    Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach.

  1. Advances in instrumentation for nuclear astrophysics

    Directory of Open Access Journals (Sweden)

    S. D. Pain

    2014-04-01

    Full Text Available The study of the nuclear physics properties which govern energy generation and nucleosynthesis in the astrophysical phenomena we observe in the universe is crucial to understanding how these objects behave and how the chemical history of the universe evolved to its present state. The low cross sections and short nuclear lifetimes involved in many of these reactions make their experimental determination challenging, requiring developments in beams and instrumentation. A selection of developments in nuclear astrophysics instrumentation is discussed, using as examples projects involving the nuclear astrophysics group at Oak Ridge National Laboratory. These developments will be key to the instrumentation necessary to fully exploit nuclear astrophysics opportunities at the Facility for Rare Isotope Beams which is currently under construction.

  2. Underground nuclear astrophysics: Why and how

    Energy Technology Data Exchange (ETDEWEB)

    Best, A.; Laubenstein, M. [Laboratori Nazionali del Gran Sasso, INFN, Assergi (AQ) (Italy); Caciolli, A. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); INFN, Padova (Italy); Fueloep, Zs.; Gyuerky, Gy. [Institute for Nuclear Research (MTA Atomki), Debrecen (Hungary); Napolitani, E. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padova (Italy); Laboratori Nazionali di Legnaro, INFN, Legnaro (Italy); Rigato, V. [Laboratori Nazionali di Legnaro, INFN, Legnaro (Italy); Roca, V. [Universita di Napoli ' ' Federico II' ' , Dipartimento di Fisica, Napoli (Italy); INFN, Napoli (Italy); Szuecs, T. [Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Dresden (Germany)

    2016-04-15

    The goal of nuclear astrophysics is to measure cross-sections of nuclear physics reactions of interest in astrophysics. At stars temperatures, these cross-sections are very low due to the suppression of the Coulomb barrier. Cosmic-ray-induced background can seriously limit the determination of reaction cross-sections at energies relevant to astrophysical processes and experimental setups should be arranged in order to improve the signal-to-noise ratio. Placing experiments in underground sites, however, reduces this background opening the way towards ultra low cross-section determination. LUNA (Laboratory for Underground Nuclear Astrophysics) was pioneer in this sense. Two accelerators were mounted at the INFN National Laboratories of Gran Sasso (LNGS) allowing to study nuclear reactions close to stellar energies. A summary of the relevant technology used, including accelerators, target production and characterisation, and background treatment is given. (orig.)

  3. Astrophysics: Unexpected X-ray flares

    Science.gov (United States)

    Campana, Sergio

    2016-10-01

    Two sources of highly energetic flares have been discovered in archival X-ray data of 70 nearby galaxies. These flares have an undetermined origin and might represent previously unknown astrophysical phenomena. See Letter p.356

  4. Underground nuclear astrophysics: why and how

    CERN Document Server

    Best, A; Fülöp, Zs; Gyürky, Gy; Laubenstein, M; Napolitani, E; Rigato, V; Roca, V; Szücs, T

    2016-01-01

    The goal of nuclear astrophysics is to measure cross sections of nuclear physics reactions of interest in astrophysics. At stars temperatures, these cross sections are very low due to the suppression of the Coulomb barrier. Cosmic ray induced background can seriously limit the determination of reaction cross sections at energies relevant to astrophysical processes and experimental setups should be arranged in order to improve the signal-to-noise ratio. Placing experiments in underground sites, however, reduces this background opening the way towards ultra low cross section determination. LUNA (Laboratory for Underground Nuclear Astrophysics) was pioneer in this sense. Two accelerators were mounted at the INFN National Laboratories of Gran Sasso (LNGS) allowing to study nuclear reactions close to stellar energies. A summary of the relevant technology used, including accelerators, target production and characterisation, and background treatment is given.

  5. Link between laboratory and astrophysical radiative shocks

    CERN Document Server

    Michaut, Claire; Cavet, Cécile; Bouquet, Serge; Koenig, Michel; Vinci, Tommaso; Loupias, Bérénice

    2008-01-01

    This work provides analytical solutions describing the post-shock structure of radiative shocks growing in astrophysics and in laboratory. The equations including a cooling function $\\Lambda \\propto \\rho^{\\epsilon} P^{\\zeta} x^{\\theta}$ are solved for any values of the exponents $\\epsilon$, $\\zeta$ and $\\theta$. This modeling is appropriate to astrophysics as the observed radiative shocks arise in optically thin media. In contrast, in laboratory, radiative shocks performed using high-power lasers present a radiative precursor because the plasma is more or less optically thick. We study the post-shock region in the laboratory case and compare with astrophysical shock structure. In addition, we attempt to use the same equations to describe the radiative precursor, but the cooling function is slightly modified. In future experiments we will probe the PSR using X-ray diagnostics. These new experimental results will allow to validate our astrophysical numerical codes.

  6. The magnetic universe geophysical and astrophysical dynamo theory

    CERN Document Server

    Rüdiger, Günther

    2004-01-01

    Magnetism is one of the most pervasive features of the Universe, with planets, stars and entire galaxies all having associated magnetic fields. All of these fields are generated by the motion of electrically conducting fluids, the so-called dynamo effect. The precise details of what drives the motion, and indeed what the fluid consists of, differ widely though. In this work the authors draw upon their expertise in geophysical and astrophysical MHD to explore some of these phenomena, and describe the similarities and differences between different magnetized objects. They also explain why magn

  7. Astrophysical Jets as Hypersonic Buckshot: Laboratory Experiments and Simulations

    Science.gov (United States)

    Frank, A.; Ciardi, A.; Yirak, K.; Lebedev, S.

    2009-08-01

    Herbig-Haro (HH) jets are commonly thought of as homogeneous beams of plasma traveling at hypersonic velocities. Structure within jet beams is often attributed to periodic or ``pulsed'' variations of conditions at the jet source. In this contribution we offer an alternative to ``pulsed'' models of protostellar jets. Using direct numerical simulations and laboratory experiments we explore the possibility that jets are chains of sub-radial clumps propagating through a moving inter-clump medium. Our simulations explore an idealization of this scenario by injecting small (r rho_{jet}) spheres embedded in an otherwise smooth inter-clump jet flow. The spheres are initialized with velocities differing from the jet velocity by ˜ 15%. We find the consequences of shifting from homogeneous to heterogeneous flows are significant as clumps interact with each other and with the inter-clump medium in a variety of ways. We also present new experiments that, for the first time, directly address issues of magnetized astrophysical jets. Our experiments explore the propagation and stability of super-magnetosonic, radiatively cooled, and magnetically dominated bubbles with internal, narrow jets. The results are scalable to astrophysical environments via the similarity of dimensionless numbers controlling the dynamics in both settings. These experiments show the jets are subject to kink mode instabilities which quickly fragment the jet into narrow chains of hypersonic knots, providing support for the ``clumpy jet'' paradigm.

  8. Dictionary of geophysics, astrophysics, and astronomy

    CERN Document Server

    Matzner, Richard A

    2001-01-01

    The Dictionary of Geophysics, Astrophysics, and Astronomy provides a lexicon of terminology covering fields such as astronomy, astrophysics, cosmology, relativity, geophysics, meteorology, Newtonian physics, and oceanography. Authors and editors often assume - incorrectly - that readers are familiar with all the terms in professional literature. With over 4,000 definitions and 50 contributing authors, this unique comprehensive dictionary helps scientists to use terminology correctly and to understand papers, articles, and books in which physics-related terms appear.

  9. Graduate Program in Astrophysics in Split

    OpenAIRE

    Krajnovic, Davor

    2006-01-01

    Beginning in autumn 2008 the first generation of astronomy master students will start a 2 year course in Astrophysics offered by the Physics department of the University of Split, Croatia (http://fizika.pmfst.hr/astro/english/index.html). This unique master course in South-Eastern Europe, following the Bologna convention and given by astronomers from international institutions, offers a series of comprehensive lectures designed to greatly enhance students' knowledge and skills in astrophysics...

  10. The data sharing advantage in astrophysics

    CERN Document Server

    Dorch, S B F; Ellegaard, O

    2015-01-01

    We present here evidence for the existence of a citation advantage within astrophysics for papers that link to data. Using simple measures based on publication data from NASA Astrophysics Data System we find a citation advantage for papers with links to data receiving on the average significantly more citations per paper than papers without links to data. Furthermore, using INSPEC and Web of Science databases we investigate whether either papers of an experimental or theoretical nature display different citation behavior.

  11. Indirect techniques for astrophysical reaction rates determinations

    Science.gov (United States)

    Hammache, F.; Oulebsir, N.; Benamara, S.; De Séréville, N.; Coc, A.; Laird, A.; Stefan, I.; Roussel, P.

    2016-05-01

    Direct measurements of nuclear reactions of astrophysical interest can be challenging. Alternative experimental techniques such as transfer reactions and inelastic scattering reactions offer the possibility to study these reactions by using stable beams. In this context, I will present recent results that were obtained in Orsay using indirect techniques. The examples will concern various astrophysical sites, from the Big-Bang nucleo synthesis to the production of radioisotopes in massive stars.

  12. Cosmological and astrophysical neutrino mass measurements

    DEFF Research Database (Denmark)

    Abazajian, K.N.; Calabrese, E.; Cooray, A.;

    2011-01-01

    Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach.......Cosmological and astrophysical measurements provide powerful constraints on neutrino masses complementary to those from accelerators and reactors. Here we provide a guide to these different probes, for each explaining its physical basis, underlying assumptions, current and future reach....

  13. Technology Development for a Neutrino Astrophysical Observatory

    International Nuclear Information System (INIS)

    We propose a set of technology developments relevant to the design of an optimized Cerenkov detector for the study of neutrino interactions of astrophysical interest. Emphasis is placed on signal processing innovations that enhance significantly the quality of primary data. These technical advances, combined with field experience from a follow-on test deployment, are intended to provide a basis for the engineering design for a kilometer-scale Neutrino Astrophysical Observatory

  14. Nuclear Physics and Astrophysics of Neutrino Oscillations

    CERN Document Server

    Balantekin, A B

    2016-01-01

    For a long time very little experimental information was available about neutrino properties, even though a minute neutrino mass has intriguing cosmological and astrophysical implications. This situation has changed in recent decades: intense experimental activity to measure many neutrino properties took place. Some of these developments and their implications for astrophysics and cosmology are briefly reviewed with a particular emphasis on neutrino magnetic moments and collective neutrino oscillations

  15. Bubble Chambers for Experiments in Nuclear Astrophysics

    OpenAIRE

    DiGiovine, B.; Henderson, D.; Holt, R. J.; Rehm, K. E.; Raut, R.; Robinson, A.; Sonnenschein, A.; Rusev, G.; A.P. Tonchev; Ugalde, C.

    2015-01-01

    A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with gamma-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning...

  16. Astrophysical applications of gravitational microlensing

    Institute of Scientific and Technical Information of China (English)

    Shude Mao

    2012-01-01

    Since the first discovery of microlensing events nearly two decades ago,gravitational microlensing has accumulated tens of TBytes of data and developed into a powerful astrophysical technique with diverse applications.The review starts with a theoretical overview of the field and then proceeds to discuss the scientific highlights.(1) Microlensing observations toward the Magellanic Clouds rule out the Milky Way halo being dominated by MAssive Compact Halo Objects (MACHOs).This confirms most dark matter is non-baryonic,consistent with other observations.(2) Microlensing has discovered about 20 extrasolar planets (16 published),including the first two Jupiter-Saturn like systems and the only five "cold Neptunes" yet detected.They probe a different part of the parameter space and will likely provide the most stringent test of core accretion theory of planet formation.(3) Microlensing provides a unique way to measure the mass of isolated stars,including brown dwarfs and normal stars.Half a dozen or so stellar mass black hole candidates have also been proposed.(4) High-resolution,target-of-opportunity spectra of highly-magnified dwarf stars provide intriguing "age" determinations which may either hint at enhanced helium enrichment or unusual bulge formation theories.(5) Microlensing also measured limb-darkening profiles for close to ten giant stars,which challenges stellar atmosphere models.(6) Data from surveys also provide strong constraints on the geometry and kinematics of the Milky Way bar (through proper motions); the latter indicates predictions from current models appear to be too anisotropic compared with observations.The future of microlensing is bright given the new capabilities of current surveys and forthcoming new telescope networks from the ground and from space.Some open issues in the field are identified and briefly discussed.

  17. Nuclear astrophysics: a new era

    Energy Technology Data Exchange (ETDEWEB)

    Wiescher, Michael; Aprahamian, Ani [Department of Physics, University of Notre Dame (United States); Regan, Paddy [Department of Physics, University of Surrey (United Kingdom)

    2002-02-01

    The latest generation of radioactive-ion-beam facilities promises to shed light on the complex nuclear processes that control the evolution of stars and stellar explosions. The most fundamental question in nature is where do we come from, or, put another way, what are we made of? The late Carl Sagan poetically said that we are all made of stardust, but the origin of the elements has fascinated scientists for thousands of years. Many of the greatest medieval and renaissance scientists dabbled in alchemy, trying to create the elements that make up the cosmos, but we had to wait until the early 20th century to recognize that elements are really defined by the number of protons in the nucleus. According to our current understanding, after the big bang most of the normal or baryonic material in the universe consisted of the lightest two elements, hydrogen and helium, with only trace amounts of lithium and beryllium. All the heavier elements that occur naturally on Earth were created from this original material via a series of nuclear reactions in the cores of stars or in stellar explosions. Over the last decade, ground-based telescopes and satellite-based Observatories have opened new windows on the stars across the electromagnetic spectrum, from infrared to gamma radiation. New technology now makes it possible to observe and analyse short-lived stellar explosions. Indeed, the distribution of elements in 'planetary nebula' and in the ejecta of supernovae and novae give a direct glimpse of individual nucleosynthesis processes. In the February issue of Physics World, Michael Wiescher, Paddy Regan and Ani Aprahamian describe how sate-of-the-art facilities are set to plug many of the gaps in our understanding of nuclear astrophysics. (U.K.)

  18. Nuclear astrophysics: a new era

    International Nuclear Information System (INIS)

    The latest generation of radioactive-ion-beam facilities promises to shed light on the complex nuclear processes that control the evolution of stars and stellar explosions. The most fundamental question in nature is where do we come from, or, put another way, what are we made of? The late Carl Sagan poetically said that we are all made of stardust, but the origin of the elements has fascinated scientists for thousands of years. Many of the greatest medieval and renaissance scientists dabbled in alchemy, trying to create the elements that make up the cosmos, but we had to wait until the early 20th century to recognize that elements are really defined by the number of protons in the nucleus. According to our current understanding, after the big bang most of the normal or baryonic material in the universe consisted of the lightest two elements, hydrogen and helium, with only trace amounts of lithium and beryllium. All the heavier elements that occur naturally on Earth were created from this original material via a series of nuclear reactions in the cores of stars or in stellar explosions. Over the last decade, ground-based telescopes and satellite-based Observatories have opened new windows on the stars across the electromagnetic spectrum, from infrared to gamma radiation. New technology now makes it possible to observe and analyse short-lived stellar explosions. Indeed, the distribution of elements in 'planetary nebula' and in the ejecta of supernovae and novae give a direct glimpse of individual nucleosynthesis processes. In the February issue of Physics World, Michael Wiescher, Paddy Regan and Ani Aprahamian describe how sate-of-the-art facilities are set to plug many of the gaps in our understanding of nuclear astrophysics. (U.K.)

  19. Environmental Effects for Gravitational-wave Astrophysics

    Science.gov (United States)

    Barausse, Enrico; Cardoso, Vitor; Pani, Paolo

    2015-05-01

    The upcoming detection of gravitational waves by terrestrial interferometers will usher in the era of gravitational-wave astronomy. This will be particularly true when space-based detectors will come of age and measure the mass and spin of massive black holes with exquisite precision and up to very high redshifts, thus allowing for better understanding of the symbiotic evolution of black holes with galaxies, and for high-precision tests of General Relativity in strong-field, highly dynamical regimes. Such ambitious goals require that astrophysical environmental pollution of gravitational-wave signals be constrained to negligible levels, so that neither detection nor estimation of the source parameters are significantly affected. Here, we consider the main sources for space-based detectors - the inspiral, merger and ringdown of massive black-hole binaries and extreme mass-ratio inspirals - and account for various effects on their gravitational waveforms, including electromagnetic fields, cosmological evolution, accretion disks, dark matter, “firewalls” and possible deviations from General Relativity. We discover that the black-hole quasinormal modes are sharply different in the presence of matter, but the ringdown signal observed by interferometers is typically unaffected. The effect of accretion disks and dark matter depends critically on their geometry and density profile, but is negligible for most sources, except for few special extreme mass-ratio inspirals. Electromagnetic fields and cosmological effects are always negligible. We finally explore the implications of our findings for proposed tests of General Relativity with gravitational waves, and conclude that environmental effects will not prevent the development of precision gravitational-wave astronomy.

  20. Lunar University Network for Astrophysics Research: Comprehensive Report to The NASA Lunar Science Institute. March 1, 2012

    OpenAIRE

    Burns, Jack; Lazio, Joseph

    2012-01-01

    The Lunar University Network for Astrophysics Research (LUNAR) is a team of researchers and students at leading universities, NASA centers, and federal research laboratories undertaking investigations aimed at using the Moon as a platform for space science. LUNAR research includes Lunar Interior Physics & Gravitation using Lunar Laser Ranging (LLR), Low Frequency Cosmology and Astrophysics (LFCA), Planetary Science and the Lunar Ionosphere, Radio Heliophysics, and Exploration Science. The LUN...

  1. General Astrophysics and Comparative Planetology with the Terrestrial Planet Finder Missions

    Science.gov (United States)

    Kuchner, Marc J. (Editor)

    2005-01-01

    This document discusses the potential of the Terrestrial Planet Finder (TPF) for general astrophysics beyond its base mission, focusing on science obtainable with no or minimal modifications to the mission design, but also exploring possible modifications of TPF with high scientific merit and no impact on the basic search for extrasolar Earth analogs.

  2. Understanding and Affecting Science Teacher Candidates' Scientific Reasoning in Introductory Astrophysics

    Science.gov (United States)

    Steinberg, Richard; Cormier, Sebastien

    2013-01-01

    This study reports on a content course for science immersion teacher candidates that emphasized authentic practice of science and thinking scientifically in the context of introductory astrophysics. We explore how 122 science teacher candidates spanning three cohorts did and did not reason scientifically and how this evolved in our program. Our…

  3. Distance Measurement Solves Astrophysical Mysteries

    Science.gov (United States)

    2003-08-01

    Location, location, and location. The old real-estate adage about what's really important proved applicable to astrophysics as astronomers used the sharp radio "vision" of the National Science Foundation's Very Long Baseline Array (VLBA) to pinpoint the distance to a pulsar. Their accurate distance measurement then resolved a dispute over the pulsar's birthplace, allowed the astronomers to determine the size of its neutron star and possibly solve a mystery about cosmic rays. "Getting an accurate distance to this pulsar gave us a real bonanza," said Walter Brisken, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Monogem Ring The Monogem Ring, in X-Ray Image by ROSAT satellite CREDIT: Max-Planck Institute, American Astronomical Society (Click on Image for Larger Version) The pulsar, called PSR B0656+14, is in the constellation Gemini, and appears to be near the center of a circular supernova remnant that straddles Gemini and its neighboring constellation, Monoceros, and is thus called the Monogem Ring. Since pulsars are superdense, spinning neutron stars left over when a massive star explodes as a supernova, it was logical to assume that the Monogem Ring, the shell of debris from a supernova explosion, was the remnant of the blast that created the pulsar. However, astronomers using indirect methods of determining the distance to the pulsar had concluded that it was nearly 2500 light-years from Earth. On the other hand, the supernova remnant was determined to be only about 1000 light-years from Earth. It seemed unlikely that the two were related, but instead appeared nearby in the sky purely by a chance juxtaposition. Brisken and his colleagues used the VLBA to make precise measurements of the sky position of PSR B0656+14 from 2000 to 2002. They were able to detect the slight offset in the object's apparent position when viewed from opposite sides of Earth's orbit around the Sun. This effect, called parallax, provides a direct measurement of

  4. The applications of Complexity Theory and Tsallis Non-extensive Statistics at Solar Plasma Dynamics

    Science.gov (United States)

    Pavlos, George

    2015-04-01

    As the solar plasma lives far from equilibrium it is an excellent laboratory for testing complexity theory and non-equilibrium statistical mechanics. In this study, we present the highlights of complexity theory and Tsallis non extensive statistical mechanics as concerns their applications at solar plasma dynamics, especially at sunspot, solar flare and solar wind phenomena. Generally, when a physical system is driven far from equilibrium states some novel characteristics can be observed related to the nonlinear character of dynamics. Generally, the nonlinearity in space plasma dynamics can generate intermittent turbulence with the typical characteristics of the anomalous diffusion process and strange topologies of stochastic space plasma fields (velocity and magnetic fields) caused by the strange dynamics and strange kinetics (Zaslavsky, 2002). In addition, according to Zelenyi and Milovanov (2004) the complex character of the space plasma system includes the existence of non-equilibrium (quasi)-stationary states (NESS) having the topology of a percolating fractal set. The stabilization of a system near the NESS is perceived as a transition into a turbulent state determined by self-organization processes. The long-range correlation effects manifest themselves as a strange non-Gaussian behavior of kinetic processes near the NESS plasma state. The complex character of space plasma can also be described by the non-extensive statistical thermodynamics pioneered by Tsallis, which offers a consistent and effective theoretical framework, based on a generalization of Boltzmann - Gibbs (BG) entropy, to describe far from equilibrium nonlinear complex dynamics (Tsallis, 2009). In a series of recent papers, the hypothesis of Tsallis non-extensive statistics in magnetosphere, sunspot dynamics, solar flares, solar wind and space plasma in general, was tested and verified (Karakatsanis et al., 2013; Pavlos et al., 2014; 2015). Our study includes the analysis of solar plasma time

  5. Using the Astrophysics Source Code Library

    Science.gov (United States)

    Allen, Alice; Teuben, P. J.; Berriman, G. B.; DuPrie, K.; Hanisch, R. J.; Mink, J. D.; Nemiroff, R. J.; Shamir, L.; Wallin, J. F.

    2013-01-01

    The Astrophysics Source Code Library (ASCL) is a free on-line registry of source codes that are of interest to astrophysicists; with over 500 codes, it is the largest collection of scientist-written astrophysics programs in existence. All ASCL source codes have been used to generate results published in or submitted to a refereed journal and are available either via a download site or from an identified source. An advisory committee formed in 2011 provides input and guides the development and expansion of the ASCL, and since January 2012, all accepted ASCL entries are indexed by ADS. Though software is increasingly important for the advancement of science in astrophysics, these methods are still often hidden from view or difficult to find. The ASCL (ascl.net/) seeks to improve the transparency and reproducibility of research by making these vital methods discoverable, and to provide recognition and incentive to those who write and release programs useful for astrophysics research. This poster provides a description of the ASCL, an update on recent additions, and the changes in the astrophysics community we are starting to see because of the ASCL.

  6. NASA Astrophysics EPO Community: Enhancing STEM Instruction

    Science.gov (United States)

    Bartolone, L.; Manning, J.; Lawton, B.; Meinke, B. K.; Smith, D. A.; Schultz, G.; NASA Astrophysics EPO community

    2015-11-01

    The NASA Science Mission Directorate (SMD) Astrophysics Education and Public Outreach (EPO) community and Forum work together to capitalize on the cutting-edge discoveries of NASA Astrophysics missions to enhance Science, Technology, Engineering, and Math (STEM) instruction. In 2010, the Astrophysics EPO community identified online professional development for classroom educators and multiwavelength resources as a common interest and priority for collaborative efforts. The result is NASA's Multiwavelength Universe, a 2-3 week online professional development experience for classroom educators. The course uses a mix of synchronous sessions (live WebEx teleconferences) and asynchronous activities (readings and activities that educators complete on their own on the Moodle, and moderated by course facilitators). The NASA SMD Astrophysics EPO community has proven expertise in providing both professional development and resources to K-12 Educators. These mission- and grant-based EPO programs are uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. We present examples of how the NASA Astrophysics EPO community and Forum engage the K-12 education community in these ways, including associated metrics and evaluation findings.

  7. Analysis and Interpretation of the Plasma Dynamic Response to Additional Heating Power using different Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Manini, A

    2002-07-01

    development of this work, the Electron Cyclotron Emission system (ECE) of ASDEX Upgrade is crucial since it allows local measurements of the electron temperature with high temporal and spatial resolutions. The analysis and interpretation of perturbative MECH discharges for power deposition localisation using different diagnostics, such as ECE and SXR measurements, are presented. The most important problem is related to the phase locking between the MECH and the sawtooth activity of the plasma, which disturbs both ECE and SXR measurements. Several techniques have been adopted to circumvent this difficulty. In particular, the Singular Value Decomposition (SVD) and the Generalised Singular Value Decomposition (GSVD) have been tested in both TCV and ASDEX Upgrade discharges. However, both methods are incapable of treating the problem correctly, which leads to potential misinterpretation of the results. A new method based on system identification using the SVD (SI-SVD) is developed and applied. This method, within reasonable limits induced by the assumption of linearity, is capable of simultaneously separating the MECH from the sawtooth contributions to both ECE electron temperature measurements and SXR emission measurements. Such a method is in particular applied to a NBI heated ASDEX Upgrade discharge in which MECH is added in order to analyse electron heat transport in a mostly ion-heated plasma. Since the NBI heating is also partly modulated with short pulses, which coincide with the sawtooth crashes to improve their stability, both the MECH and the NBI deposition profiles are determined. Moreover, treating the signals with the SI-SVD procedure enables a study of the plasma dynamic response also at higher MECH harmonic numbers. The procedure is then used to analyse MECH discharges in TCV using different diagnostics. The profiles determined using the ECE and soft X-ray measurements are compared and interpreted, demonstrating in particular that line integrated soft X

  8. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  9. Astrophysical Fluid Dynamics via Direct Statistical Simulation

    CERN Document Server

    Tobias, S M; Marston, J B

    2010-01-01

    In this paper we introduce the concept of Direct Statistical Simulation (DSS) for astrophysical flows. This technique may be appropriate for problems in astrophysical fluids where the instantaneous dynamics of the flows are of secondary importance to their statistical properties. We give examples of such problems including mixing and transport in planets, stars and disks. The method is described for a general set of evolution equations, before we consider the specific case of a spectral method optimised for problems on a spherical surface. The method is illustrated for the simplest non-trivial example of hydrodynamics and MHD on a rotating spherical surface. We then discuss possible extensions of the method both in terms of computational methods and the range of astrophysical problems that are of interest.

  10. Astrophysics Source Code Library: Incite to Cite!

    CERN Document Server

    DuPrie, Kimberly; Berriman, Bruce; Hanisch, Robert J; Mink, Jessica; Nemiroff, Robert J; Shamir, Lior; Shortridge, Keith; Taylor, Mark B; Teuben, Peter; Wallin, John F

    2013-01-01

    The Astrophysics Source Code Library (ASCL, http://ascl.net/) is an online registry of over 700 source codes that are of interest to astrophysicists, with more being added regularly. The ASCL actively seeks out codes as well as accepting submissions from the code authors, and all entries are citable and indexed by ADS. All codes have been used to generate results published in or submitted to a refereed journal and are available either via a download site or froman identified source. In addition to being the largest directory of scientist-written astrophysics programs available, the ASCL is also an active participant in the reproducible research movement with presentations at various conferences, numerous blog posts and a journal article. This poster provides a description of the ASCL and the changes that we are starting to see in the astrophysics community as a result of the work we are doing.

  11. Strange quark matter in explosive astrophysical systems

    CERN Document Server

    Sagert, I; Hempel, M; Pagliara, G; Schaffner-Bielich, J; Thielemann, F -K; Liebendörfer, M

    2010-01-01

    Explosive astrophysical systems, such as supernovae or compact star binary mergers, provide conditions where strange quark matter can appear. The high degree of isospin asymmetry and temperatures of several MeV in such systems may cause a transition to the quark phase already around saturation density. Observable signals from the appearance of quark matter can be predicted and studied in astrophysical simulations. As input in such simulations, an equation of state with an integrated quark matter phase transition for a large temperature, density and proton fraction range is required. Additionally, restrictions from heavy ion data and pulsar observation must be considered. In this work we present such an approach. We implement a quark matter phase transition in a hadronic equation of state widely used for astrophysical simulations and discuss its compatibility with heavy ion collisions and pulsar data. Furthermore, we review the recently studied implications of the QCD phase transition during the early post-bou...

  12. Doppler tomography in fusion plasmas and astrophysics

    CERN Document Server

    Salewski, Mirko; Heidbrink, Bill; Jacobsen, Asger Schou; Korsholm, Soren Bang; Leipold, Frank; Madsen, Jens; Moseev, Dmitry; Nielsen, Stefan Kragh; Rasmussen, Jesper; Stagner, Luke; Steeghs, Danny; Stejner, Morten; Tardini, Giovani; Weiland, Markus

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion D-alpha (FIDA) spectroscopy measurements in magnetically confined plasma, the D-alpha-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright spots, spiral structures, and flow patterns. Fusion plasma Doppler tomography has lead to an image of the fast-ion velocity distribution function in the tokamak ASDEX Upgrade. This image matched numerical simulations very well. Here we discuss achievements of the Doppler tomography approach, its promise and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography, and what ...

  13. Doppler tomography in fusion plasmas and astrophysics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Heidbrink, W. W.;

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion Dα (FIDA) spectroscopy measurements in magnetically confined plasma......, the Dα-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright...... and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography and what can be learned by comparison of these applications....

  14. The Astrophysics Science Division Annual Report 2008

    Science.gov (United States)

    Oegerle, William; Reddy, Francis; Tyler, Pat

    2009-01-01

    The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. This report includes the Division's activities during 2008.

  15. The Cosmic Battery in Astrophysical Accretion Disks

    CERN Document Server

    Contopoulos, Ioannis; Katsanikas, Matthaios

    2015-01-01

    The aberrated radiation pressure at the inner edge of the accretion disk around an astrophysical black hole imparts a relative azimuthal velocity on the electrons with respect to the ions which gives rise to a ring electric current that generates large scale poloidal magnetic field loops. This is the Cosmic Battery established by Contopoulos and Kazanas in 1998. In the present work we perform realistic numerical simulations of this important astrophysical mechanism in advection-dominated accretion flows-ADAF. We confirm the original prediction that the inner parts of the loops are continuously advected toward the central black hole and contribute to the growth of the large scale magnetic field, whereas the outer parts of the loops are continuously diffusing outward through the turbulent accretion flow. This process of inward advection of the axial field and outward diffusion of the return field proceeds all the way to equipartition, thus generating astrophysically significant magnetic fields on astrophysicall...

  16. Laboratory Astrophysics Division of the AAS (LAD)

    Science.gov (United States)

    Salama, Farid; Drake, R. P.; Federman, S. R.; Haxton, W. C.; Savin, D. W.

    2012-01-01

    The purpose of the Laboratory Astrophysics Division (LAD) is to advance our understanding of the Universe through the promotion of fundamental theoretical and experimental research into the underlying processes that drive the Cosmos. LAD represents all areas of astrophysics and planetary sciences. The first new AAS Division in more than 30 years, the LAD traces its history back to the recommendation from the scientific community via the White Paper from the 2006 NASA-sponsored Laboratory Astrophysics Workshop. This recommendation was endorsed by the Astronomy and Astrophysics Advisory Committee (AAAC), which advises the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA), and the U.S. Department of Energy (DOE) on selected issues within the fields of astronomy and astrophysics that are of mutual interest and concern to the agencies. In January 2007, at the 209th AAS meeting, the AAS Council set up a Steering Committee to formulate Bylaws for a Working Group on Laboratory Astrophysics (WGLA). The AAS Council formally established the WGLA with a five-year mandate in May 2007, at the 210th AAS meeting. From 2008 through 2012, the WGLA annually sponsored Meetings in-a-Meeting at the AAS Summer Meetings. In May 2011, at the 218th AAS meeting, the AAS Council voted to convert the WGLA, at the end of its mandate, into a Division of the AAS and requested draft Bylaws from the Steering Committee. In January 2012, at the 219th AAS Meeting, the AAS Council formally approved the Bylaws and the creation of the LAD. The inaugural gathering and the first business meeting of the LAD were held at the 220th AAS meeting in Anchorage in June 2012. You can learn more about LAD by visiting its website at http://lad.aas.org/ and by subscribing to its mailing list.

  17. News and Views: Challenges of Relativistic Astrophysics

    Science.gov (United States)

    Opher, Reuven

    2013-12-01

    I discuss some of the most outstanding challenges in relativistic astrophysics in the subjects of compact objects (black holes and neutron stars), dark sector (dark matter and dark energy), plasma astrophysics (origin of jets, cosmic rays, and magnetic fields), and the primordial universe (physics at the beginning of the Universe). In these four subjects, I discuss 12 of the most important challenges. These challenges give us insight into new physics that can only be studied in the large scale universe. The near-future possibilities, in observations and theory, for addressing these challenges are also discussed.

  18. The astrophysical gravitational wave stochastic background

    Institute of Scientific and Technical Information of China (English)

    Tania Regimbau

    2011-01-01

    A stochastic background of gravitational waves with astrophysical origins may have resulted from the superposition of a large number of unresolved sources since the beginning of stellar activity.Its detection would put very strong constraints on the physical properties of compact objects, the initial mass function and star formarion history.On the other hand, it could be a ‘noise' that would mask the stochastic background of its cosmological origin.We review the main astrophysical processes which are able to produce a stochastic background and discuss how they may differ from the primordial contribution in terms of statistical properties.Current detection methods are also presented.

  19. Advances in astronomy and astrophysics 9

    CERN Document Server

    Kopal, Zdenek

    1972-01-01

    Advances in Astronomy and Astrophysics, Volume 9 covers reviews on the advances in astronomy and astrophysics. The book presents reviews on the Roche model and its applications to close binary systems. The text then describes the part played by lunar eclipses in the evolution of astronomy; the classical theory of lunar eclipses; deviations from geometrical theory; and the methods of photometric observations of eclipses. The problems of other phenomena related in one way or another to lunar eclipses are also considered. The book further tackles the infrared observation on the eclipsed moon, as

  20. On the saturation of astrophysical dynamos

    DEFF Research Database (Denmark)

    Dorch, Bertil; Archontis, Vasilis

    2004-01-01

    In the context of astrophysical dynamos we illustrate that the no-cosines flow, with zero mean helicity, can drive fast dynamo action and we study the dynamo's mode of operation during both the linear and non-linear saturation regimes. It turns out that in addition to a high growth rate in the li......In the context of astrophysical dynamos we illustrate that the no-cosines flow, with zero mean helicity, can drive fast dynamo action and we study the dynamo's mode of operation during both the linear and non-linear saturation regimes. It turns out that in addition to a high growth rate...

  1. Bibliometric indicators of young authors in astrophysics

    DEFF Research Database (Denmark)

    Havemann, Frank; Larsen, Birger

    2015-01-01

    We test 16 bibliometric indicators with respect to their validity at the level of the individual researcher by estimating their power to predict later successful researchers. We compare the indicators of a sample of astrophysics researchers who later co-authored highly cited papers before...... their first landmark paper with the distributions of these indicators over a random control group of young authors in astronomy and astrophysics. We find that field and citation-window normalisation substantially improves the predicting power of citation indicators. The sum of citation numbers normalised...

  2. Advances in astronomy and astrophysics 7

    CERN Document Server

    Kopal, Zdenek

    2013-01-01

    Advances in Astronomy and Astrophysics, Volume 7 covers reviews about the advances in astronomy and astrophysics. The book presents reviews on the scattering of electrons by diatomic molecules and on Babcock's theory of the 22-year solar cycle and the latitude drift of the sunspot zone. The text then describes reviews on the structures of the terrestrial planets (Earth, Venus, Mars, Mercury) and on type III solar radio bursts. The compact and dispersed cosmic matter is also considered with regard to the search for new cosmic objects and phenomena and on the nature of the ref shift from compact

  3. Transient Astrophysics with the Square Kilometre Array

    CERN Document Server

    Fender, Rob; Macquart, Jean-Pierre; Donnarumma, Immacolata; Murphy, Tara; Deller, Adam; Paragi, Zsolt; Chatterjee, Shami

    2015-01-01

    This chapter provides an overview of the possibilities for transient and variable-source astrophysics with the Square Kilometre Array. While subsequent chapters focus on the astrophysics of individual events, we focus on the broader picture, and how to maximise the science coming from the telescope. The SKA as currently designed will be a fantastic and ground-breaking facility for radio transient studies, but the scientifc yield will be dramatically increased by the addition of (i) near-real-time commensal searches of data streams for events, and (ii) on occasion, rapid robotic response to Target-of-Opprtunity style triggers.

  4. White Paper on Nuclear Astrophysics and Low Energy Nuclear Physics - Part 1. Nuclear Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Arcones, Almudena [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, Jutta E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Others, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-04

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21 - 23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9 - 10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12 - 13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long-standing key questions are well within reach in the coming decade.

  5. Laboratory Astrophysics and Collimated Stellar Outflows The Production of Radiatively Cooled Hypersonic Plasma Jets

    CERN Document Server

    Lebedev, S V; Beg, F N; Bland, S N; Ciardi, A; Ampleford, D; Hughes, S; Haines, M G; Frank, A; Blackman, E G; Gardiner, T

    2002-01-01

    We present first results of astrophysically relevant experiments where highly supersonic plasma jets are generated via conically convergent flows. The convergent flows are created by electrodynamic acceleration of plasma in a conical array of fine metallic wires (a modification of the wire array Z-pinch). Stagnation of plasma flow on the axis of symmetry forms a standing conical shock effectively collimating the flow in the axial direction. This scenario is essentially similar to that discussed by Canto\\' ~and collaborators as a purely hydrodynamic mechanism for jet formation in astrophysical systems. Experiments using different materials (Al, Fe and W) show that a highly supersonic ($M\\sim 20$), well-collimated jet is generated when the radiative cooling rate of the plasma is significant. We discuss scaling issues for the experiments and their potential use for numerical code verification. The experiments also may allow direct exploration of astrophysically relevant issues such as collimation, stability and ...

  6. The Role of Magnetic Fields in Relativistic Astrophysical Jets

    Science.gov (United States)

    Hamlin, Nathaniel; Newman, W. I.

    2012-05-01

    We explore, analytically and by numerical simulation, the evolution of the Kelvin-Helmholtz (KH) instability in a relativistic magnetized astrophysical jet. Our results successfully reproduce numerous magnetohydrodynamic features observed in relativistic astrophysical environments. The KH instability arises from a variation in flow speed orthogonal to the flow. Many astrophysical jets are relativistic, evidenced by apparent superluminal motion, and are likely collimated by a magnetic field, according to commonly accepted models. We find convergence of our numerical results between the hydrodynamic, magnetohydrodynamic, relativistic hydrodynamic, and relativistic magnetohydrodynamic regimes. We observe complementarity between fluid flow and magnetic field behavior. The early nonlinear regime corresponds to the formation of large vortices connected by a dual filamentary structure reminiscent of the cosmic double helix in the extragalactic jet 3C 273. These vortices are disrupted by the field, followed by a complex turbulent regime, and then an approach to an equilibrium configuration consisting of flow-aligned filaments. For stronger fields, this process occurs more rapidly, and sufficiently strong fields suppress vortices entirely. The jet also widens and decelerates by an amount depending on field strength. These results are in qualitative agreement with observations of numerous jets, including NGC 5128, 3C 273, and HH 30. Relativistic flows break synchronicity between longitudinal and transverse motions, thereby destabilizing the system, and enhancing the complexity of vortex disruption and turbulent breakdown. This desynchronization also causes early numerical breakdown at high Lorentz factors, a long-standing problem. Using a uniform-flow model, we provide the first mathematical analysis showing that for sufficiently high Lorentz factors, artificial diffusion not only fails to suppress numerical instability, but introduces growing modes which destabilize the

  7. Physics and astrophysics with dark matter particles

    International Nuclear Information System (INIS)

    The DAMA/Nal set-up has investigated the annual modulation signature over seven annual cycles achieving 6.3 σ C.L. model independent evidence for the presence of a Dark Matter particle component in the galactic halo. Some of the Physics and Astrophysics topics which can be addressed by DAMA/LIBRA are also introduced

  8. Astrophysics, cosmology and high energy physics

    International Nuclear Information System (INIS)

    A brief survey is given of some topics in astrophysics and cosmology, with special emphasis on the inter-relation between the properties of the early Universe and recent ideas in high energy physics, and on simple order-of-magnitude arguments showing how the scales and dimensions of cosmic phenomena are related to basic physical constants. (orig.)

  9. Nuclear astrophysics experiments with radioactive beams

    International Nuclear Information System (INIS)

    In Nuclear Astrophysics, experiments with radioactive beams present particular problems (e.g. low beam intensity, large background) to which specific solutions (i.e. non-standard detection setup) can be brought. Selected reactions measured in Louvain-la-Neuve are treated as practical examples. (author)

  10. Nuclear astrophysics and the Trojan Horse Method

    Science.gov (United States)

    Spitaleri, C.; La Cognata, M.; Lamia, L.; Mukhamedzhanov, A. M.; Pizzone, R. G.

    2016-04-01

    In this review, we discuss the new recent results of the Trojan Horse Method that is used to determine reaction rates for nuclear processes in several astrophysical scenarios. The theory behind this technique is shortly presented. This is followed by an overview of some new experiments that have been carried out using this indirect approach.

  11. The Trojan Horse Method in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Spitaleri, C.; Cherubini, S.; Del Zoppo, A.; Di Pietrob, A.; Figuerab, P.; Gulino, M.; Lattuadab, M.; Miljanic, Dstroke; Musumarra, A.; Pellegriti, M.G.; Pizzone, R.G.; Rolfs, C.; Romano, S.; Tudisco, S.; Tumino, A

    2003-05-19

    The basic features of the Trojan Horse Method are discussed together with a review of recent applications, aimed to extract the bare astrophysical S(E)-factor for several two-body processes. In this framework information on electron screening potential U{sub e} was obtained from the comparison with direct experiments.

  12. Workshop on gravitational waves and relativistic astrophysics

    Indian Academy of Sciences (India)

    Patrick Das Gupta

    2004-10-01

    Discussions related to gravitational wave experiments viz. LIGO and LISA as well as to observations of supermassive black holes dominated the workshop sessions on gravitational waves and relativistic astrophysics in the ICGC-2004. A summary of seven papers that were presented in these workshop sessions has been provided in this article.

  13. New Directions in Black Hole Astrophysics

    Science.gov (United States)

    Reynolds, C. S.

    2002-12-01

    The astrophysics of accreting black holes has been a scientific focus of most major future X-ray missions. In this presentation, I will describe how our science goals and expectations have been effected by new data from Chandra and XMM-Newton as well as new theoretical work. I will argue on the basis of XMM-Newton data that black hole spin does not manifest itself through subtle effects but may have dramatic astrophysical consequences. If this is correct, the exotic astrophysics of black hole spin, including astrophysical realizations of the Penrose and Blandford-Znajek processes, will be a principal focus of Constellation-X, XEUS and MAXIM. On the other hand, data from the late stages of the RXTE/ASCA missions as well as XMM-Newton suggest that the simple technique of relativistic X-ray iron line reverberation mapping, which was originally touted as a good method for studying the inner accretion disk, may be hard to realize. Finally, I will discuss recent theoretical/simulation work on the appearance of a MHD turbulent accretion disk around a black hole. Such simulations may be a good framework to understand future timing observations of Galactic Black Hole Candidates and their quasi-periodic oscillations. They also suggest a quantitative way of measuring the space-time geometry around supermassive black holes in AGN.

  14. Radioactive ion beams in nuclear astrophysics

    Science.gov (United States)

    Gialanella, L.

    2016-09-01

    Unstable nuclei play a crucial role in the Universe. In this lecture, after a short introduction to the field of Nuclear Astrophysics, few selected cases in stellar evolution and nucleosynthesis are discussed to illustrate the importance and peculiarities of processes involving unstable species. Finally, some experimental techniques useful for measurements using radioactive ion beams and the perspectives in this field are presented.

  15. Astronomical optical interferometry, II: Astrophysical results

    Directory of Open Access Journals (Sweden)

    Jankov S.

    2011-01-01

    Full Text Available Optical interferometry is entering a new age with several ground- based long-baseline observatories now making observations of unprecedented spatial resolution. Based on a great leap forward in the quality and quantity of interferometric data, the astrophysical applications are not limited anymore to classical subjects, such as determination of fundamental properties of stars; namely, their effective temperatures, radii, luminosities and masses, but the present rapid development in this field allowed to move to a situation where optical interferometry is a general tool in studies of many astrophysical phenomena. Particularly, the advent of long-baseline interferometers making use of very large pupils has opened the way to faint objects science and first results on extragalactic objects have made it a reality. The first decade of XXI century is also remarkable for aperture synthesis in the visual and near-infrared wavelength regimes, which provided image reconstructions from stellar surfaces to Active Galactic Nuclei. Here I review the numerous astrophysical results obtained up to date, except for binary and multiple stars milliarcsecond astrometry, which should be a subject of an independent detailed review, taking into account its importance and expected results at microarcsecond precision level. To the results obtained with currently available interferometers, I associate the adopted instrumental settings in order to provide a guide for potential users concerning the appropriate instruments which can be used to obtain the desired astrophysical information.

  16. Neutron cross sections of importance to astrophysics

    International Nuclear Information System (INIS)

    Neutron reactions of importance to the various stellar burning cycles are discussed. The role of isomeric states in the branched s-process is considered for particular cases. Neutron cross section needs for the 187Re-187Os, 87Rb-87Sr clocks for nuclear cosmochronology are discussed. Other reactions of interest to astrophysical processes are presented. 35 references

  17. Minicourses in Astrophysics, Modular Approach, Vol. II.

    Science.gov (United States)

    Illinois Univ., Chicago.

    This is the second of a two-volume minicourse in astrophysics. It contains chapters on the following topics: stellar nuclear energy sources and nucleosynthesis; stellar evolution; stellar structure and its determination; and pulsars. Each chapter gives much technical discussion, mathematical treatment, diagrams, and examples. References are…

  18. Recent Status of Astrophysical S17

    Science.gov (United States)

    Motobayashi, T.

    2002-12-01

    The present status of the astrophysical S factor for the 7Be(p, γ)8B reaction is reviewed. Because of its importance for the solar neutrino problem, the reaction has been extensively studied. Three independent methods, the direct capture, the Coulomb dissociation and the ANC method, give almost consistent results within 10-20% accuracy.

  19. Photon Orbital Angular Momentum in Astrophysics

    OpenAIRE

    Harwit, Martin

    2003-01-01

    Astronomical observations of the orbital angular momentum of photons, a property of electromagnetic radiation that has come to the fore in recent years, have apparently never been attempted. Here, I show that measurements of this property of photons have a number of astrophysical applications.

  20. Neutron shielding for particle astrophysics experiments

    CERN Document Server

    McMillan, J E

    2005-01-01

    Particle astrophysics experiments often require large volume neutron shields which are formed from hydrogenous material. This note reviews some of the available materials in an attempt to find the most cost effective solution. Raw polymer pellets and Water Extended Polyester (WEP) ae discussed in detail. Suppliers for some materials are given.

  1. Virtually Lossless Compression of Astrophysical Images

    Directory of Open Access Journals (Sweden)

    Stefano Baronti

    2005-09-01

    Full Text Available We describe an image compression strategy potentially capable of preserving the scientific quality of astrophysical data, simultaneously allowing a consistent bandwidth reduction to be achieved. Unlike strictly lossless techniques, by which moderate compression ratios are attainable, and conventional lossy techniques, in which the mean square error of the decoded data is globally controlled by users, near-lossless methods are capable of locally constraining the maximum absolute error, based on user's requirements. An advanced lossless/near-lossless differential pulse code modulation (DPCM scheme, recently introduced by the authors and relying on a causal spatial prediction, is adjusted to the specific characteristics of astrophysical image data (high radiometric resolution, generally low noise, etc.. The background noise is preliminarily estimated to drive the quantization stage for high quality, which is the primary concern in most of astrophysical applications. Extensive experimental results of lossless, near-lossless, and lossy compression of astrophysical images acquired by the Hubble space telescope show the advantages of the proposed method compared to standard techniques like JPEG-LS and JPEG2000. Eventually, the rationale of virtually lossless compression, that is, a noise-adjusted lossles/near-lossless compression, is highlighted and found to be in accordance with concepts well established for the astronomers' community.

  2. Nuclear astrophysics and the Trojan Horse Method

    Energy Technology Data Exchange (ETDEWEB)

    Spitaleri, C. [University of Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Laboratori Nazionali del Sud - INFN, Catania (Italy); La Cognata, M.; Pizzone, R.G. [Laboratori Nazionali del Sud - INFN, Catania (Italy); Lamia, L. [University of Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Mukhamedzhanov, A.M. [Texas A and M University, Cyclotron Institute, College Station, TX (United States)

    2016-04-15

    In this review, we discuss the new recent results of the Trojan Horse Method that is used to determine reaction rates for nuclear processes in several astrophysical scenarios. The theory behind this technique is shortly presented. This is followed by an overview of some new experiments that have been carried out using this indirect approach. (orig.)

  3. The trojan horse method as indirect technique in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A; Spitaleri, C; Cherubini, S; Crucilla, V; Fu, C; Gulino, M; La Cognata, M; Lamia, L; Pizzone, R G; Puglia, S M R; Rapisarda, G G; Romano, S; Sergi, M L [Dipartimento di Metodologie Fisiche e Chimiche per l' Ingegneria - Universita di Catania, Catania (Italy); Elekes, Z; Fueloep, Z; Gyuerky, G; Kiss, G; Mukhamedzhanov, A [ATOMKI - Debrecen (Hungary); Goldberg, V [Cyclotron Institute, Texas A and M University, College Station (United States); Rolfs, C [Ruhr-Universitaet, Bochum (Germany)], E-mail: tumino@lns.infn.it (and others)

    2008-05-15

    The Trojan Horse Method is a successful indirect technique for nuclear astrophysics. It allows one to measure astrophysical rearrangement reactions down to the relevant energies, providing a successful alternative path to measure the astrophysical S(E) factor. The basic features will be discussed and some recent results will be presented.

  4. 3rd Session of the Sant Cugat Forum on Astrophysics

    CERN Document Server

    Gravitational wave astrophysics

    2015-01-01

    This book offers review chapters written by invited speakers of the 3rd Session of the Sant Cugat Forum on Astrophysics — Gravitational Waves Astrophysics. All chapters have been peer reviewed. The book goes beyond normal conference proceedings in that it provides a wide panorama of the astrophysics of gravitational waves and serves as a reference work for researchers in the field.

  5. 76 FR 66998 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting.

    Science.gov (United States)

    2011-10-28

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting... Space Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory... following topic: --Astrophysics Division Update --Results from Acting Astrophysics Division...

  6. 78 FR 20356 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2013-04-04

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... following topics: --Astrophysics Division Update --Report from Astrophysics Roadmap Team --James Webb...

  7. Astrophysics Conducted by the Lunar University Network for Astrophysics Research (LUNAR) and the Center for Lunar Origins (CLOE)

    OpenAIRE

    Burns, Jack O.; Lazio, T. Joseph W.; Bottke, William

    2012-01-01

    [Abridged] The Moon is a unique platform from and on which to conduct astrophysical measurements. The Lunar University Network for Astrophysics Research (LUNAR) and the Center for Lunar Origins and Evolution (CLOE) teams within the NASA Lunar Science Institute (NLSI) are illustrating how the Moon can be used as a platform to advance important goals in astrophysics. Of relevance to Astrophysics and aligned with NASA strategic goals, all three of the primary research themes articulated by New W...

  8. MICA: The Meta-Institute for Computational Astrophysics

    Science.gov (United States)

    McMillan, Stephen L. W.; Djorgovski, S. G.; Hut, P.; Vesperini, E.; Knop, R.; Portegies Zwart, S.

    2009-05-01

    We describe MICA, the Meta Institute for Computational Astrophysics, the first professional scientific and educational, non-profit organization based in virtual worlds [VWs]. Most MICA activities are currently conducted in Second Life, arguably the most popular and best developed VW; we plan to expand our presence into other VWs as those venues evolve. The goals of MICA include (1) exploration, development and promotion of VWs and virtual reality [VR] technologies for professional research in astronomy and related fields; (2) development of novel networking venues and mechanisms for virtual scientific communication and interaction, including professional meetings, visualization, and telecollaboration; (3) use of VWs and VR technologies for education and public outreach; and (4) exchange of ideas and joint efforts with other scientific disciplines in promoting these goals for science and scholarship in general. We present representative example of MICA activities and achievements, and outline plans for expansion of the organization. For more information on MICA, please visit http://mica-vw.org .

  9. Nuclear structure studies for the astrophysical r-process

    CERN Document Server

    Pfeiffer, B; Thielemann, F K; Walters, W B

    2001-01-01

    The production of the heaviest elements in nature occurs via the r-process, i.e. a combination of rapid neutron captures, the inverse photodisintegrations, and slower beta sup - -decays, beta-delayed processes as well as fission and possibly interactions with intense neutrino fluxes. A correct understanding and modeling requires the knowledge of nuclear properties far from stability and a detailed prescription of the astrophysical environment. Experiments at radioactive ion beam facilities have played a pioneering role in exploring the characteristics of nuclear structure in terms of masses and beta-decay properties. Initial examinations paid attention to highly unstable nuclei with magic neutron numbers and their beta-decay properties, related to the location and height of r-process peaks, while recent activities focus on the evolution of shell effects at large distances from the valley of stability. We show in site-independent applications the effect of both types of nuclear properties on r-process abundanc...

  10. Considerations about the apparent superluminal expansions in astrophysics

    International Nuclear Information System (INIS)

    The ortodox models devised to explain the apparent ''superluminal expansions'' observed in astrophysics, and here briefly summarized and discussed together with th experimental data, do not seem to be to much successful. Especially when confronted with the most recent observations, suggesting complicated expansion patterns, even with possible accelerations. At this point it may be, therefore, of some interest to explore the possible alternative models in which actual superluminal motion take place. To prepare the ground one starts from a variational principle, introduces the elements of a tachyon mechanics within special relativity, and argues about the expected behaviour of tachyonic objects when interacting (gravitationally, for instance) among themselves or with ordinary matter. Then the simplest ''superluminal models'', paying particular attention to the observations which they would give rise to are revie wed and developed. It is concluded that some of them appear to be physically acceptable and are statistically favoured with respect to the ortodox ones

  11. Gravity-mediated (or composite) Dark Matter confronts astrophysical data

    Science.gov (United States)

    Lee, Hyun Min; Park, Myeonghun; Sanz, Verónica

    2014-05-01

    We consider the astrophysical bounds on a new form of dark matter, the so called Gravity-mediated Dark Matter. In this scenario, dark matter communicates with us through a mediator sector composed of gravitational resonances, namely a new scalar (radion) and a massive spin-two resonance (massive graviton). We consider specific models motivated by natural electroweak symmetry breaking or weak-scale dark matter in the context of models in warped extra-dimensions and their composite duals. The main Dark Matter annihilation mechanism is due to the interactions of KK gravitons to gauge bosons that propagate in bulk. We impose the bounds on monochromatic or continuum photons from Fermi-LAT and HESS. We also explore scenarios in which the Fermi gamma-ray line could be a manifestation of Gravity-mediated Dark Matter.

  12. On the vertical-shear instability in astrophysical discs

    CERN Document Server

    Barker, Adrian J

    2015-01-01

    We explore the linear stability of astrophysical discs exhibiting vertical shear, which arises when there is a radial variation in the temperature or entropy. Such discs are subject to a "vertical-shear instability", which recent nonlinear simulations have shown to drive hydrodynamic activity in the MRI-stable regions of protoplanetary discs. We first revisit locally isothermal discs using the quasi-global reduced model derived by Nelson et al. (2013). This analysis is then extended to global axisymmetric perturbations in a cylindrical domain. We also derive and study a reduced model describing discs with power law radial entropy profiles ("locally polytropic discs"), which are somewhat more realistic in that they possess physical (as opposed to numerical) surfaces. In all cases the fastest growing modes have very short wavelengths and are localised at the disc surfaces (if present), where the vertical shear is maximal. An additional class of modestly growing vertically global body modes is excited, correspon...

  13. Gravity-mediated (or Composite) Dark Matter Confronts Astrophysical Data

    CERN Document Server

    Lee, Hyun Min; Sanz, Veronica

    2014-01-01

    We consider the astrophysical bounds on a new form of dark matter, the so called Gravity-mediated Dark Matter. In this scenario, dark matter communicates with us through a mediator sector composed of gravitational resonances, namely a new scalar (radion) and a massive spin-two resonance (massive graviton). We consider specific models motivated by natural electroweak symmetry breaking or weak-scale dark matter in the context of models in warped extra-dimensions and their composite duals. The main Dark Matter annihilation mechanism is due to the interactions of KK gravitons to gauge bosons that propagate in bulk. We impose the bounds on monochromatic or continuum photons from Fermi-LAT and HESS. We also explore scenarios in which the Fermi gamma-ray line could be a manifestation of Gravity-mediated Dark Matter.

  14. White Paper on Nuclear Astrophysics and Low Energy Nuclear Physics - Part 1. Nuclear Astrophysics

    International Nuclear Information System (INIS)

    This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21-23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9-10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12-13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long-standing key questions are well within reach in the coming decade.

  15. The Astrophysics of Ultrahigh Energy Cosmic Rays

    CERN Document Server

    Kotera, Kumiko

    2011-01-01

    The origin of the highest energy cosmic rays is still unknown. The discovery of their sources will reveal the workings of the most energetic astrophysical accelerators in the universe. Current observations show a spectrum consistent with an origin in extragalactic astrophysical sources. Candidate sources range from the birth of compact objects to explosions related to gamma-ray bursts or to events in active galaxies. We discuss the main effects of propagation from cosmologically distant sources including interactions with cosmic background radiation and magnetic fields. We examine possible acceleration mechanisms leading to a survey of candidate sources and their signatures. New questions arise from an observed hint of sky anisotropies and an unexpected evolution of composition indicators. Future observations may reach the necessary sensitivity to achieve charged particle astronomy and to observe ultrahigh energy photons and neutrinos, which will further illuminate the workings of the universe at these extrem...

  16. Unique Astrophysics in the Lyman Ultraviolet

    CERN Document Server

    Tumlinson, Jason; Kriss, Gerard; France, Kevin; McCandliss, Stephan; Sembach, Ken; Fox, Andrew; Tripp, Todd; Jenkins, Edward; Beasley, Matthew; Danforth, Charles; Shull, Michael; Stocke, John; Lehner, Nicolas; Howk, Christopher; Froning, Cynthia; Green, James; Oliveira, Cristina; Fullerton, Alex; Blair, Bill; Kruk, Jeff; Sonneborn, George; Penton, Steven; Wakker, Bart; Prochaska, Xavier; Vallerga, John; Scowen, Paul

    2012-01-01

    There is unique and groundbreaking science to be done with a new generation of UV spectrographs that cover wavelengths in the "Lyman Ultraviolet" (LUV; 912 - 1216 Ang). There is no astrophysical basis for truncating spectroscopic wavelength coverage anywhere between the atmospheric cutoff (3100 Ang) and the Lyman limit (912 Ang); the usual reasons this happens are all technical. The unique science available in the LUV includes critical problems in astrophysics ranging from the habitability of exoplanets to the reionization of the IGM. Crucially, the local Universe (z <= 0.1) is entirely closed to many key physical diagnostics without access to the LUV. These compelling scientific problems require overcoming these technical barriers so that future UV spectrographs can extend coverage to the Lyman limit at 912 Ang.

  17. Problems and Progress in Astrophysical Dynamos

    CERN Document Server

    Vishniac, E T; Cho, J

    2002-01-01

    Astrophysical objects with negligible resistivity are often threaded by large scale magnetic fields. The generation of these fields is somewhat mysterious, since a magnetic field in a perfectly conducting fluid cannot change the flux threading a fluid element, or the field topology. Classical dynamo theory evades this limit by assuming that magnetic reconnection is fast, even for vanishing resistivity, and that the large scale field can be generated by the action of kinetic helicity. Both these claims have been severely criticized, and the latter appears to conflict with strong theoretical arguments based on magnetic helicity conservation and a series of numerical simulations. Here we discuss recent efforts to explain fast magnetic reconnection through the topological effects of a weak stochastic magnetic field component. We also show how mean-field dynamo theory can be recast in a form which respects magnetic helicity conservation, and how this changes our understanding of astrophysical dynamos. Finally, we ...

  18. Critical ionisation velocity effects in astrophysical plasmas

    International Nuclear Information System (INIS)

    Critical ionisation velocity effects are relevant to astrophysical situations where neutral gas moves through a magnetised plasma. The experimental significance of the critical velocity is well established and the physical basis is now becoming clear. The underlying mechanism depends on the combined effects of electron impact ionisation and electron energisation by collective plasma interactions. For low density plasmas a theory based on a circular process involving electron heating through a modified two stream instability has been developed. Several applications of critical velocity effects to astrophysical plasmas have been discussed in the literature. The importance of the effect in any particular case may be determined from a detailed consideration of energy and momentum balance, using appropriate atomic rate coefficients and taking full account of collective plasma processes. (Auth.)

  19. Magnetic field amplification in turbulent astrophysical plasmas

    CERN Document Server

    Federrath, Christoph

    2016-01-01

    Magnetic fields play an important role in astrophysical accretion discs, and in the interstellar and intergalactic medium. They drive jets, suppress fragmentation in star-forming clouds and can have a significant impact on the accretion rate of stars. However, the exact amplification mechanisms of cosmic magnetic fields remain relatively poorly understood. Here I start by reviewing recent advances in the numerical and theoretical modelling of the 'turbulent dynamo', which may explain the origin of galactic and inter-galactic magnetic fields. While dynamo action was previously investigated in great detail for incompressible plasmas, I here place particular emphasis on highly compressible astrophysical plasmas, which are characterised by strong density fluctuations and shocks, such as the interstellar medium. I find that dynamo action works not only in subsonic plasmas, but also in highly supersonic, compressible plasmas, as well as for low and high magnetic Prandtl numbers. I further present new numerical simu...

  20. Neutrino particle astrophysics: status and outlook

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The discovery of astrophysical neutrinos at high energy by IceCube raises a host of questions: What are the sources? Is there a Galactic as well as an extragalactic component? How does the astrophysical spectrum continue to lower energy where the dominant signal is from atmospheric neutrinos? Is there a measureable flux of cosmogenic neutrinos at higher energy? What is the connection to cosmic rays? At what level and in what energy region should we expect to see evidence of the π0 decay photons that must accompany the neutrinos at production? Such questions are stimulating much theoretical activity and many multi-wavelength follow-up observations as well as driving plans for new detectors. My goal in this presentation will be to connect the neutrino data and their possible interpretations to ongoing multi-messenger observations and to the design of future detectors.

  1. Optimizing Laboratory Experiments for Dynamic Astrophysical Phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D; Remington, B

    2005-09-13

    To make a laboratory experiment an efficient tool for the studying the dynamical astrophysical phenomena, it is desirable to perform them in such a way as to observe the scaling invariance with respect to the astrophysical system under study. Several examples are presented of such scalings in the area of magnetohydrodynamic phenomena, where a number of scaled experiments have been performed. A difficult issue of the effect of fine-scale dissipative structures on the global scale dissipation-free flow is discussed. The second part of the paper is concerned with much less developed area of the scalings relevant to the interaction of an ultra-intense laser pulse with a pre-formed plasma. The use of the symmetry arguments in such experiments is also considered.

  2. Status reports of supercomputing astrophysics in Japan

    International Nuclear Information System (INIS)

    The Workshop on Supercomputing Astrophysics was held at National Laboratory for High Energy Physics (KEK, Tsukuba) from August 31 to September 2, 1989. More than 40 participants of physicists, astronomers were attendant and discussed many topics in the informal atmosphere. The main purpose of this workshop was focused on the theoretical activities in computational astrophysics in Japan. It was also aimed to promote effective collaboration between the numerical experimentists working on supercomputing technique. The various subjects of the presented papers of hydrodynamics, plasma physics, gravitating systems, radiative transfer and general relativity are all stimulating. In fact, these numerical calculations become possible now in Japan owing to the power of Japanese supercomputer such as HITAC S820, Fujitsu VP400E and NEC SX-2. (J.P.N.)

  3. Astrophysical data analysis with information field theory

    Energy Technology Data Exchange (ETDEWEB)

    Enßlin, Torsten, E-mail: ensslin@mpa-garching.mpg.de [Max Planck Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching, Germany and Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, D-80539 München (Germany)

    2014-12-05

    Non-parametric imaging and data analysis in astrophysics and cosmology can be addressed by information field theory (IFT), a means of Bayesian, data based inference on spatially distributed signal fields. IFT is a statistical field theory, which permits the construction of optimal signal recovery algorithms. It exploits spatial correlations of the signal fields even for nonlinear and non-Gaussian signal inference problems. The alleviation of a perception threshold for recovering signals of unknown correlation structure by using IFT will be discussed in particular as well as a novel improvement on instrumental self-calibration schemes. IFT can be applied to many areas. Here, applications in in cosmology (cosmic microwave background, large-scale structure) and astrophysics (galactic magnetism, radio interferometry) are presented.

  4. Numerical MHD Codes for Modeling Astrophysical Flows

    CERN Document Server

    Koldoba, A V; Lii, P S; Comins, M L; Dyda, S; Romanova, M M; Lovelace, R V E

    2015-01-01

    We describe a Godunov-type magnetohydrodynamic (MHD) code based on the Miyoshi and Kusano (2005) solver which can be used to solve various astrophysical hydrodynamic and MHD problems. The energy equation is in the form of entropy conservation. The code has been implemented on several different coordinate systems: 2.5D axisymmetric cylindrical coordinates, 2D Cartesian coordinates, 2D plane polar coordinates, and fully 3D cylindrical coordinates. Viscosity and diffusivity are implemented in the code to control the accretion rate in the disk and the rate of penetration of the disk matter through the magnetic field lines. The code has been utilized for the numerical investigations of a number of different astrophysical problems, several examples of which are shown.

  5. The Future of Gamma Ray Astrophysics

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Over the past decade, gamma ray astrophysics has entered the astrophysical mainstream. Extremely successful space-borne (GeV) and ground-based (TeV) detectors, combined with a multitude of partner telescopes, have revealed a fascinating “astroscape" of active galactic nuclei, pulsars, gamma ray bursts, supernova remnants, binary stars, star-forming galaxies, novae much more, exhibiting major pathways along which large energy releases can flow. From  a basic physics perspective, exquisitely sensitive measurements have constrained the nature of dark matter, the cosmological origin of magnetic field and the properties of black holes. These advances have motivated the development of new facilities, including HAWC, DAMPE, CTA and SVOM, which will further our understanding of the high energy universe. Topics that will receive special attention include merging neutron star binaries, clusters of galaxies, galactic cosmic rays and putative, TeV dark matter.

  6. Vision Forward for NASA's Astrophysics Education Program

    Science.gov (United States)

    Hasan, Hashima; Sheth, Kartik J.

    2016-01-01

    NASA has recently re-structured its Science Education program with the competitive selection of twenty-seven programs. Of these, ~60% are relevant to Astrophysics, and three have primarily Astrophysics content. A brief overview of the rationale for re-structuring will be presented. We have taken a strategic approach, building on our science-discipline based legacy and looking at new approaches given Stakeholder priorities. We plan to achieve our education goals with the selection of organizations that utilize NASA data, products, or processes to meet NASA's education objectives; and by enabling our scientists and engineers with education professionals, tools, and processes to better meet user needs. Highlights of the selected programs will be presented, and how they enable the vision going forward of achieving the goal of enabling NASA scientists and engineers to engage more effectively with learners of all ages.

  7. Numerical Methods for Radiation Magnetohydrodynamics in Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Klein, R I; Stone, J M

    2007-11-20

    We describe numerical methods for solving the equations of radiation magnetohydrodynamics (MHD) for astrophysical fluid flow. Such methods are essential for the investigation of the time-dependent and multidimensional dynamics of a variety of astrophysical systems, although our particular interest is motivated by problems in star formation. Over the past few years, the authors have been members of two parallel code development efforts, and this review reflects that organization. In particular, we discuss numerical methods for MHD as implemented in the Athena code, and numerical methods for radiation hydrodynamics as implemented in the Orion code. We discuss the challenges introduced by the use of adaptive mesh refinement in both codes, as well as the most promising directions for future developments.

  8. Clustering with phylogenetic tools in astrophysics

    CERN Document Server

    Fraix-Burnet, Didier

    2016-01-01

    Phylogenetic approaches are finding more and more applications outside the field of biology. Astrophysics is no exception since an overwhelming amount of multivariate data has appeared in the last twenty years or so. In particular, the diversification of galaxies throughout the evolution of the Universe quite naturally invokes phylogenetic approaches. We have demonstrated that Maximum Parsimony brings useful astrophysical results, and we now proceed toward the analyses of large datasets for galaxies. In this talk I present how we solve the major difficulties for this goal: the choice of the parameters, their discretization, and the analysis of a high number of objects with an unsupervised NP-hard classification technique like cladistics. 1. Introduction How do the galaxy form, and when? How did the galaxy evolve and transform themselves to create the diversity we observe? What are the progenitors to present-day galaxies? To answer these big questions, observations throughout the Universe and the physical mode...

  9. Modern fluid dynamics for physics and astrophysics

    CERN Document Server

    Regev, Oded; Yecko, Philip A

    2016-01-01

    This book grew out of the need to provide students with a solid introduction to modern fluid dynamics. It offers a broad grounding in the underlying principles and techniques used, with some emphasis on applications in astrophysics and planetary science. The book comprehensively covers recent developments, methods and techniques, including, for example, new ideas on transitions to turbulence (via transiently growing stable linear modes), new approaches to turbulence (which remains the enigma of fluid dynamics), and the use of asymptotic approximation methods, which can give analytical or semi-analytical results and complement fully numerical treatments. The authors also briefly discuss some important considerations to be taken into account when developing a numerical code for computer simulation of fluid flows. Although the text is populated throughout with examples and problems from the field of astrophysics and planetary science, the text is eminently suitable as a general introduction to fluid dynamics. It...

  10. TeV Gamma-Ray Astrophysics

    CERN Document Server

    Ribó, M

    2008-01-01

    The window of TeV Gamma-Ray Astrophysics was opened less than two decades ago, when the Crab Nebula was detected for the first time. After several years of development, the technique used by imaging atmospheric Cherenkov telescopes like HESS, MAGIC or VERITAS, is now allowing to conduct sensitive observations in the TeV regime. Water Cherenkov instruments like Milagro are also providing the first results after years of integration time. Different types of extragalactic and galactic sources have been detected, showing a variety of interesting phenomena that are boosting theory in very high energy gamma-ray astrophysics. Here I review some of the most interesting results obtained up to now, making special emphasis in the field of X-ray/gamma-ray binaries.

  11. Bubble Chambers for Experiments in Nuclear Astrophysics

    CERN Document Server

    DiGiovine, B; Holt, R J; Rehm, K E; Raut, R; Robinson, A; Sonnenschein, A; Rusev, G; Tonchev, A P; Ugalde, C

    2015-01-01

    A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with gamma-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas tar...

  12. Astrophysical Effects of Scalar Dark Matter Miniclusters

    OpenAIRE

    Zurek, Kathryn M.; Hogan, Craig J.; Quinn, Thomas R.

    2006-01-01

    We model the formation, evolution and astrophysical effects of dark compact Scalar Miniclusters (``ScaMs''). These objects arise when a scalar field, with an axion-like or Higgs-like potential, undergoes a second order phase transition below the QCD scale. Such a scalar field may couple too weakly to the standard model to be detectable directly through particle interactions, but may still be detectable by gravitational effects, such as lensing and baryon accretion by large, gravitationally bo...

  13. Neutrino masses in astrophysics and cosmology

    International Nuclear Information System (INIS)

    Astrophysical and cosmological arguments and observations give us the most restrictive constraints on neutrino masses, electromagnetic couplings, and other properties. Conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino oscillations may well solve the solar neutrino problem, and can have a significant impact on supernova physics. (author) 14 figs., tabs., 33 refs

  14. Astrophysical Constraints on Singlet Scalars at LHC

    OpenAIRE

    Hertzberg, Mark P.(Center for Theoretical Physics and Dept. of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA); Masoumi, Ali

    2016-01-01

    We consider the viability of new heavy gauge singlet scalar particles at the LHC. Our motivation for this study comes from the possibility of a new particle with mass ~ 750 GeV decaying significantly into two photons at LHC, but our analysis applies more broadly. We show that there are significant constraints from astrophysics and cosmology on the simplest UV complete models that incorporate such a particle and its associated collider signal. The simplest and most obvious UV complete model th...

  15. Colour-Charged Quark Matter in Astrophysics?

    Institute of Scientific and Technical Information of China (English)

    QIU Cong-Xin; XU Ren-Xin

    2006-01-01

    Colour confinement is only a supposition, which has not yet been proven in QCD. Here we propose that macroscopic quark-gluon plasma in astrophysics could hardly maintain colourless because of causality. It is expected that the existence of chromatic strange quark stars as well as chromatic strangelets preserved from the QCD phase transition in the early Universe could be unavoidable if their colourless correspondents do exist.

  16. Coulomb dissociation studies for astrophysical thermonuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Motobayashi, T. [Dept. of Physics, Rikkyo Univ., Toshima, Tokyo (Japan)

    1998-06-01

    The Coulomb dissociation method was applied to several radiative capture processes of astrophysical interest. The method has an advantage of high experimental efficiency, which allow measurements with radioactive nuclear beams. The reactions {sup 13}N(p,{gamma}){sup 14}O and {sup 7}Be(p,{gamma}){sup 8}B are mainly discussed. They are the key reaction in the hot CNO cycle in massive stars and the one closely related to the solar neutrino problem, respectively. (orig.)

  17. The Planck Surveyor mission: astrophysical prospects

    OpenAIRE

    De Zotti, G.; Toffolatti, L.; Argüeso, F.; Davies, R. D.; Mazzotta, P.; Partridge, R. B.; Smoot, G. F.; Vittorio, N.

    1999-01-01

    Although the Planck Surveyor mission is optimized to map the cosmic microwave background anisotropies, it will also provide extremely valuable information on astrophysical phenomena. We review our present understanding of Galactic and extragalactic foregrounds relevant to the mission and discuss on one side, Planck's impact on the study of their properties and, on the other side, to what extent foreground contamination may affect Planck's ability to accurately determine cosmological parameter...

  18. Selected problems in astrophysics of compact objects

    OpenAIRE

    Sedrakian, Armen

    2012-01-01

    I review three problems in astrophysics of compacts stars: (i) the phase diagram of warm pair-correlated nuclear matter a sub-saturation densities at finite isospin asymmtery; (ii) the Standard Model neutrino emission from superfluid phases in neutron stars within the Landau theory of Fermi (superfluid) liquids; (iii) the beyond Standard Model physics of axionic cooling of compact stars by the Cooper pair-breaking processes.

  19. Historical perspective on astrophysical MHD simulations

    CERN Document Server

    Norman, Michael L

    2010-01-01

    This contribution contains the introductory remarks that I presented at IAU Symposium 270 on ``Computational Star Formation" held in Barcelona, Spain, May 31 -- June 4, 2010. I discuss the historical development of numerical MHD methods in astrophysics from a personal perspective. The recent advent of robust, higher order-accurate MHD algorithms and adaptive mesh refinement numerical simulations promises to greatly improve our understanding of the role of magnetic fields in star formation.

  20. Astrophysical and terrestrial neutrinos in Supernova detectors

    International Nuclear Information System (INIS)

    Supernova (SN) explosions are the place of very fundamental phenomena, whose privileged messengers are neutrinos. But such events are very rare. Then, SN detection has to be combined with other purposes. The recent developments of SN detectors have been associated with developments of underground particle physics (proton decay, monopoles ...). But here, I will restrict myself to discuss the possibilities for a supernova detector to be sensitive to other sources of neutrinos, astrophysical or terrestrial

  1. Large Format Detector Arrays for Astrophysics

    Science.gov (United States)

    Moseley, Harvey

    2006-01-01

    Improvements in detector design and advances in fabrication techniques has resulted in devices which can reach fundamental sensitivity limits in many cases. Many pressing astrophysical questions require large arrays of such sensitive detectors. I will describe the state of far infrared through millimeter detector development at NASA/GSFC, the design and production of large format arrays, and the initial deployment of these powerful new tools.

  2. Neutrino masses in astrophysics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Raffelt, G.G. [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    1996-11-01

    Astrophysical and cosmological arguments and observations give us the most restrictive constraints on neutrino masses, electromagnetic couplings, and other properties. Conversely, massive neutrinos would contribute to the cosmic dark-matter density and would play an important role for the formation of structure in the universe. Neutrino oscillations may well solve the solar neutrino problem, and can have a significant impact on supernova physics. (author) 14 figs., tabs., 33 refs.

  3. Statistical Learning in High Energy and Astrophysics

    OpenAIRE

    Zimmermann, J.

    2005-01-01

    This thesis studies the performance of statistical learning methods in high energy and astrophysics where they have become a standard tool in physics analysis. They are used to perform complex classification or regression by intelligent pattern recognition. This kind of artificial intelligence is achieved by the principle ``learning from examples'': The examples describe the relationship between detector events and their classification. The application of statistical learning ...

  4. CPT violations in Astrophysics and Cosmology

    CERN Document Server

    Auriemma, G

    2007-01-01

    In this paper it is given a brief review of the current limits on the magnitude of CPT and Lorentz Invariance violations, currently predicted in connection with quantum gravity and string/M-theory, that can be derived from astrophysical and cosmological data. Even if not completely unambiguous, these observational tests of fundamental physics are complementary to the ones obtained by accelerator experiments and by ground or space based direct experiments, because potentially can access very high energies and large distances.

  5. Impact of THM reaction rates for astrophysics

    Science.gov (United States)

    Lamia, L.; Spitaleri, C.; Tognelli, E.; Degl'Innocenti, S.; Pizzone, R. G.; Moroni, P. G. Prada; Puglia, S. M. R.; Romano, S.; Sergi, M. L.

    2015-10-01

    Burning reaction S(E)-factor determinations are among the key ingredients for stellar models when one has to deal with energy generation evaluation and the genesis of the elements at stellar conditions. To by pass the still present uncertainties in extrapolating low-energies values, S(E)-factor measurements for charged-particle induced reactions involving light elements have been made available by devote Trojan Horse Method (THM) experiments. The recent results are here discussed together with their impact in astrophysics.

  6. Acceleration of Astrophysical Simulations with Special Hardware

    OpenAIRE

    Marcus Martinez, Guillermo Anibal

    2011-01-01

    This work presents the raceSPH and raceGRAV accelerator libraries, designed to interface astrophysical simulations with special-purpose hardware. The raceSPH focuses on the acceleration of Smoothed Particle Hydrodynamics (SPH), a method for approximating force interactions in fluid dynamics. Accelerators used range from vectorizing units on the microprocessors to Field Programmable Gate Arrays (FPGAs) and Graphics Processing Units (GPUs), and speed-ups range from 1.2x to 28x when measured in ...

  7. The Astrophysics Source Code Library: An Update

    Science.gov (United States)

    Allen, Alice; Nemiroff, R. J.; Shamir, L.; Teuben, P. J.

    2012-01-01

    The Astrophysics Source Code Library (ASCL), founded in 1999, takes an active approach to sharing astrophysical source code. ASCL's editor seeks out both new and old peer-reviewed papers that describe methods or experiments that involve the development or use of source code, and adds entries for the found codes to the library. This approach ensures that source codes are added without requiring authors to actively submit them, resulting in a comprehensive listing that covers a significant number of the astrophysics source codes used in peer-reviewed studies. The ASCL moved to a new location in 2010, and has over 300 codes in it and continues to grow. In 2011, the ASCL (http://asterisk.apod.com/viewforum.php?f=35) has on average added 19 new codes per month; we encourage scientists to submit their codes for inclusion. An advisory committee has been established to provide input and guide the development and expansion of its new site, and a marketing plan has been developed and is being executed. All ASCL source codes have been used to generate results published in or submitted to a refereed journal and are freely available either via a download site or from an identified source. This presentation covers the history of the ASCL and examines the current state and benefits of the ASCL, the means of and requirements for including codes, and outlines its future plans.

  8. Cosmology and particle astrophysics. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, L.; Goobar, A. [Stockholm Univ. (Sweden). Dept. of Physics

    2006-07-01

    Beginning with some basic facts about the observable universe the authors consider in successive chapters the complete range of topics that make up a degree course in cosmology and particle astrophysics. The outstanding feature of this book is that it is self-contained, in that no specialised knowledge is required on the part of the reader, apart from basic undergraduate mathematics and physics. This paperback edition will again target students of physics, astrophysics and cosmology at the advanced undergraduate level or early graduate level. One of the book's biggest strong points is that the authors rapidly involve students in the most exciting of today's developments in the field in a simple and self-contained manner, relegating the more technical aspects to appendices. The worked examples throughout the book, and summaries at the end of each chapter, which were expanded in the second edition, have been very well received by students. This book offers advanced undergraduate level and beginning graduate level students a highly readable, yet comprehensive review of particle astrophysics. Competing books cover this topic at too advanced a level for this readership. (orig.)

  9. The Astrophysics Science Division Annual Report 2009

    Science.gov (United States)

    Oegerle, William (Editor); Reddy, Francis (Editor); Tyler, Pat (Editor)

    2010-01-01

    The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum - from gamma rays to radio wavelengths - as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions - WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the astronomical community, and enable future missions by conceiving new concepts and inventing new technologies.

  10. Goddard's Astrophysics Science Division Annual Report 2011

    Science.gov (United States)

    Centrella, Joan; Reddy, Francis; Tyler, Pat

    2012-01-01

    The Astrophysics Science Division(ASD) at Goddard Space Flight Center(GSFC)is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radiowavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contract imaging techniques to serch for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, and provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and suppport the astronomical community, and enable future missions by conceiving new conepts and inventing new technologies.

  11. Goddard's Astrophysics Science Division Annual Report 2013

    Science.gov (United States)

    Weaver, Kimberly A. (Editor); Reddy, Francis J. (Editor); Tyler, Patricia A. (Editor)

    2014-01-01

    The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for two orbiting astrophysics missions Fermi Gamma-ray Space Telescope and Swift as well as the Science Support Center for Fermi. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the astronomical community, and enable future missions by conceiving new concepts and inventing new technologies.

  12. Study of plasma dynamics in a modulated pulsed power magnetron discharge using a time-resolved Langmuir probe

    International Nuclear Information System (INIS)

    Modulated pulse power (MPP) technology is a derivative of high power pulsed magnetron sputtering that allows unprecedented user control over the growth process, although the critical time-dependent plasma properties during the power pulse have not been studied until now. Using a MPP plasma generator, pulses of custom voltage waveforms were generated and applied to the cathode of a 36 cm diameter circular planar magnetron. The I-V characteristics of the pulses are separable into distinct discharge stages. A time-resolved triple Langmuir probe was introduced to measure the temporal evolution of the plasma. Typical electron density of 5x1017 m-3 and electron temperature of 10 eV during the pulse were calculated from measured parameters. Plasma behaviors were observed to closely depend on the pulse waveforms. Various parameters, including pulse current, pulse frequency, pressure, and distance from the target, also affected the electron density and temperature, providing degrees of freedom to optimize the sputtering processes. The effects of each parameter on the pulsed plasma dynamics are discussed and then attributed to mechanisms of electron impact ionization, gas heating, and magnetic confinement.

  13. Plasma physics of extreme astrophysical environments.

    Science.gov (United States)

    Uzdensky, Dmitri A; Rightley, Shane

    2014-03-01

    Among the incredibly diverse variety of astrophysical objects, there are some that are characterized by very extreme physical conditions not encountered anywhere else in the Universe. Of special interest are ultra-magnetized systems that possess magnetic fields exceeding the critical quantum field of about 44 TG. There are basically only two classes of such objects: magnetars, whose magnetic activity is manifested, e.g., via their very short but intense gamma-ray flares, and central engines of supernovae (SNe) and gamma-ray bursts (GRBs)--the most powerful explosions in the modern Universe. Figuring out how these complex systems work necessarily requires understanding various plasma processes, both small-scale kinetic and large-scale magnetohydrodynamic (MHD), that govern their behavior. However, the presence of an ultra-strong magnetic field modifies the underlying basic physics to such a great extent that relying on conventional, classical plasma physics is often not justified. Instead, plasma-physical problems relevant to these extreme astrophysical environments call for constructing relativistic quantum plasma (RQP) physics based on quantum electrodynamics (QED). In this review, after briefly describing the astrophysical systems of interest and identifying some of the key plasma-physical problems important to them, we survey the recent progress in the development of such a theory. We first discuss the ways in which the presence of a super-critical field modifies the properties of vacuum and matter and then outline the basic theoretical framework for describing both non-relativistic and RQPs. We then turn to some specific astrophysical applications of relativistic QED plasma physics relevant to magnetar magnetospheres and to central engines of core-collapse SNe and long GRBs. Specifically, we discuss the propagation of light through a magnetar magnetosphere; large-scale MHD processes driving magnetar activity and responsible for jet launching and propagation in

  14. Enduring Quests-Daring Visions (NASA Astrophysics in the Next Three Decades)

    CERN Document Server

    Kouveliotou, C; Batalha, N; Bean, J; Bentz, M; Cornish, N; Dressler, A; Figueroa-Feliciano, E; Gaudi, S; Guyon, O; Hartmann, D; Kalirai, J; Niemack, M; Ozel, F; Reynolds, C; Roberge, A; Straughn, K Sheth A; Weinberg, D; Zmuidzinas, J

    2014-01-01

    The past three decades have seen prodigious advances in astronomy and astrophysics. Beginning with the exploration of our solar system and continuing through the pioneering Explorers and Great Observatories of today, NASA missions have made essential contributions to these advances. This roadmap presents a science-driven 30-year vision for the future of NASA Astrophysics that builds on these achievements to address some of our most ancient and fundamental questions: Are we alone? How did we get here? How does the universe work? The search for the answers constitutes the Enduring Quests of this roadmap. Building on the priorities identified in New Worlds, New Horizons, we envision future science investigations laid out in three Eras, with each representing roughly ten years of mission development in a given field. The immediate Near-Term Era covers ongoing NASA-led activities and planned missions. This will be followed by the missions of the Formative Era, which will build on the preceding technological develo...

  15. FOREWORD: Nuclear Physics in Astrophysics V

    Science.gov (United States)

    Auerbach, Naftali; Hass, Michael; Paul, Michael

    2012-02-01

    The fifth edition of the bi-annual 'Nuclear Physics in Astrophysics (NPA)' conference series was held in Eilat, Israel on April 3-8, 2011. This Conference is also designated as the 24th Nuclear Physics Divisional Conference of the EPS. The main purpose of this conference, as that of the four previous ones in this series, is to deal with those aspects of nuclear physics that are directly related to astrophysics. The concept of such a meeting was conceived by the Nuclear Physics Board of the European Physical Society in 1998. At that time, the idea of such a conference was quite new and it was decided that this meeting would be sponsored by the EPS. The first meeting, in January 2001, was planned and organized in Eilat, Israel. Due to international circumstances the conference was moved to Debrecen, Hungary. Subsequent conferences were held in Debrecen again, in Dresden, Germany, and in Frascati, Italy (moved from Gran Sasso due to the tragic earthquake that hit the L'Aquila region). After 10 years the conference finally returned to Eilat, the originally envisioned site. Eilat is a resort town located on the shore of the Gulf of Eilat, which connects Israel to the Red Sea and further south to the Indian Ocean. It commands spectacular views of the desert and mountains, offering unique touristic attractions. The local scientific backdrop of the conference is the fact that the Israeli scientific scene exhibits a wide variety of research activities in many areas of nuclear physics and astrophysics. A new accelerator, SARAF at Soreq Nuclear Research Center is presently undergoing final acceptance tests. SARAF will serve as a platform for production of radioactive ion beams and nuclear-astrophysics research in Israel. The meeting in Eilat was organized by four Israeli scientific institutions, Hebrew University, Soreq Nuclear Research Center, Tel Aviv University and the Weizmann Institute of Science. The welcome reception and lectures were held at the King Solomon hotel and

  16. BOOK REVIEW: Particle Astrophysics (Second Edition)

    Science.gov (United States)

    Bell, Nicole

    2009-07-01

    Particle astrophysics, the interface of elementary particle physics with astrophysics and cosmology, is a rapidly evolving field. Perkins' book provides a nice introduction to this field, at a level appropriate for senior undergraduate students. Perkins develops the foundations underlying both the particle and astrophysics areas, and also covers some of the most recent developments in this field. The latter is an appealing feature, as students rarely encounter topics of current research in their undergraduate textbooks. Part 1 of the text introduces the elementary particle content, and interactions, of the standard model of particle physics. Relativity is addressed at the level of special relativistic kinematics, the equivalence principle and the Robertson-Walker metric. Part 2 covers cosmology, starting with the expansion of the Universe and basic thermodynamics. It then moves on to primordial nucleosynthesis, baryogenesis, dark matter, dark energy, structure formation and the cosmic microwave background. Part 3 covers cosmic rays, stellar evolution, and related topics. Cutting edge topics include the use of the cosmological large scale structure power spectrum to constrain neutrino mass, the creation of the baryon asymmetry via leptogenesis, and the equation of state for dark energy. While the treatment of many topics is quite brief, the level of depth is about right for undergraduates who are being exposed to these topics for the first time. The breadth of topics spanned is excellent. Perkins does a good job connecting theory with the experimental underpinnings, and of simplifying the theoretical presentation of complex subjects to a level that senior undergraduate students should find accessible. Each chapter includes a number of exercises. Brief solutions are provided for all the exercises, while fully worked solutions are provided for a smaller subset.

  17. A high energy photon polarimeter for astrophysics

    OpenAIRE

    Eingorn, Maxim; Fernando, Lakma; Vlahovic, Branislav; Ilie, Cosmin; Wojtsekhowski, Bogdan; Urciuoli, Guido Maria; De Persio, Fulvio; Meddi, Franco

    2015-01-01

    A high-energy photon polarimeter for astrophysics studies in the energy range from 20 MeV to 1000 MeV is considered. The proposed concept uses a stack of silicon micro-strip detectors where they play the roles of both a converter and a tracker. The purpose of this paper is to outline the parameters of such a polarimeter and to estimate the productivity of measurements. Our study supported by a Monte Carlo simulation shows that with a one-year observation period the polarimeter will provide 6%...

  18. Physics, Astrophysics and Cosmology with Gravitational Waves

    Directory of Open Access Journals (Sweden)

    Sathyaprakash B. S.

    2009-03-01

    Full Text Available Gravitational wave detectors are already operating at interesting sensitivity levels, and they have an upgrade path that should result in secure detections by 2014. We review the physics of gravitational waves, how they interact with detectors (bars and interferometers, and how these detectors operate. We study the most likely sources of gravitational waves and review the data analysis methods that are used to extract their signals from detector noise. Then we consider the consequences of gravitational wave detections and observations for physics, astrophysics, and cosmology.

  19. Astrophysical imaging with the Darwin IR interferometer

    CERN Document Server

    Röttgering, H J A; Eiroa, C; Labbé, I; Rudnick, G

    2003-01-01

    The proposed infrared space interferometry mission Darwin has two main aims: (i) to detect and characterize exo-planets similar to the Earth, and (ii) to carry out astrophysical imaging in the wavelength range 6 - 20 micron at a sensitivity similar to JWST, but at an angular resolution up to 100 times higher. In this contribution we will first briefly discuss the imaging performance of the Darwin mission. We will then discuss how Darwin will contribute in a very significant way to our understanding of the formation and evolution of planets, stars, galaxies, and super-massive black-holes located at the centers of galaxies.

  20. Emission lines from hot astrophysical plasmas

    Science.gov (United States)

    Raymond, John C.

    The spectral lines which dominate the X-ray emission of hot, optically thin astrophysical plasmas reflect the elemental abundances, temperature distribution, and other physical parameters of the emitting gas. The accuracy and level of detail with which these parameters can be inferred are limited by the measurement uncertainties and uncertainties in atomic rates used to compute the model spectrum. This paper discusses the relative importance and the likely uncertainties in the various atomic rates and the likely uncertainties in the overall ionization balance and spectral line emissivities predicted by the computer codes currently used to fit X-ray spectral data.

  1. Astrophysical Black Holes: Evidence of a Horizon?

    Science.gov (United States)

    Colpi, Monica

    In this Lecture Note we first follow a short account of the history of the black hole hypothesis. We then review on the current status of the search for astrophysical black holes with particular attention to the black holes of stellar origin. Later, we highlight a series of observations that reveal the albeit indirect presence of supermassive black holes in galactic nuclei, with mention to forthcoming experiments aimed at testing directly the black hole hypothesis. We further focus on evidences of a black hole event horizon in cosmic sources.

  2. Theoretically palatable flavor combinations of astrophysical neutrinos

    CERN Document Server

    Bustamante, Mauricio; Winter, Walter

    2015-01-01

    The flavor composition of high-energy astrophysical neutrinos can reveal the particle physics governing their production, propagation, and interaction. The IceCube Collaboration has published the first experimental determination of the ratio of each flavor to the total flux. We present, as a theoretical counterpart, new results for the full range of received flavor ratios for arbitrary flavor ratios in the sources. With just standard neutrino mixing, this range is quite small. Even when a broad class of new-physics effects is included, it remains surprisingly small. Our results will allow IceCube to more quickly identify when their measurements imply standard, new, or truly exotic physics.

  3. Engineering considerations for large astrophysics projects

    Science.gov (United States)

    Hogg, David W.

    2014-01-01

    Modern astrophysics projects involve interactions among scientific objectives, hardware capabilities, operational constraints, and data-analysis methodologies, all mediated by complex software. I discuss trade-offs between hardware and software costs, resolve some age-old tensions between the taking of science data and calibration data, and promote some ideas about getting the most out of our data using probabilistic inference. I illustrate my points with examples taken from the SDSS, P1640, Kepler, and Euclid projects. The key idea is that we will only benefit maximally from the next generation of enormous data-taking projects if we design our operations and software with great care.

  4. Reduced MHD and Astrophysical Fluid Dynamics

    Science.gov (United States)

    Arter, Wayne

    2011-08-01

    Recent work has shown a relationship between between the equations of Reduced Magnetohydrodynamics (RMHD), used to model magnetic fusion laboratory experiments, and incompressible magnetoconvection (IMC), employed in the simulation of astrophysical fluid dynamics (AFD), which means that the two systems are mathematically equivalent in certain geometries. Limitations on the modelling of RMHD, which were found over twenty years ago, are reviewed for an AFD audience, together with hitherto unpublished material on the role of finite-time singularities in the discrete equations used to model fluid dynamical systems. Possible implications for turbulence modelling are mentioned.

  5. A quarter century of astrophysics with Japan

    OpenAIRE

    Yock, Philip

    2015-01-01

    On February 23 1987 a supernova (exploding star) was observed in the Large Cloud of Magellan, the brightest supernova in 400 years. It spurred the commencement of collaborative research in astrophysics between Japan and New Zealand that is still ongoing after 25 years. The initial aim of the two countries was to search for evidence of cosmic rays being emitted by the supernova in a project named JANZOS. A large cosmic ray detector was installed near the summit of the Black Birch range in Marl...

  6. Isometric embeddings in cosmology and astrophysics

    Indian Academy of Sciences (India)

    Gareth Amery; Jothi Moodley; James Paul Londal

    2011-09-01

    Recent interest in higher-dimensional cosmological models has prompted some signifi-cant work on the mathematical technicalities of how one goes about embedding spacetimes into some higher-dimensional space. We survey results in the literature (existence theorems and simple explicit embeddings); briefly outline our work on global embeddings as well as explicit results for more complex geometries; and provide some examples. These results are contextualized physically, so as to provide a foundation for a detailed commentary on several key issues in the field such as: the meaning of `Ricci equivalent’ embeddings; the uniqueness of local (or global) embeddings; symmetry inheritance properties; and astrophysical constraints.

  7. Dimensional analysis and group theory in astrophysics

    CERN Document Server

    Kurth, Rudolf

    2013-01-01

    Dimensional Analysis and Group Theory in Astrophysics describes how dimensional analysis, refined by mathematical regularity hypotheses, can be applied to purely qualitative physical assumptions. The book focuses on the continuous spectral of the stars and the mass-luminosity relationship. The text discusses the technique of dimensional analysis, covering both relativistic phenomena and the stellar systems. The book also explains the fundamental conclusion of dimensional analysis, wherein the unknown functions shall be given certain specified forms. The Wien and Stefan-Boltzmann Laws can be si

  8. Distance Correlation Methods for Discovering Associations in Large Astrophysical Databases

    OpenAIRE

    Martinez-Gomez, Elizabeth; Richards, Mercedes T.; Richards, Donald St. P.

    2013-01-01

    High-dimensional, large-sample astrophysical databases of galaxy clusters, such as the Chandra Deep Field South COMBO-17 database, provide measurements on many variables for thousands of galaxies and a range of redshifts. Current understanding of galaxy formation and evolution rests sensitively on relationships between different astrophysical variables; hence an ability to detect and verify associations or correlations between variables is important in astrophysical research. In this paper, w...

  9. Plasma dynamic synthesis and obtaining ultrafine powders of iron oxides with high content of ε-Fe2O3

    Science.gov (United States)

    Sivkov, Alexander; Naiden, Evgenii; Ivashutenko, Alexander; Shanenkov, Ivan

    2016-05-01

    The ultrafine iron oxide powders were successfully synthesized using the plasma dynamic synthesis method, based on the use of a coaxial magnetoplasma accelerator with the iron electrode system. The synthesis was implemented in the high-speed iron-containing plasma jet, flowing into the space of the sealed chamber, filled with the gaseous mixture of oxygen and argon at different ratios. The XRD investigations showed that the synthesized products were heterophase and consisted of three main phases such as magnetite Fe3O4, hematite α-Fe2O3 and ε-Fe2O3. The SEM data confirmed the presence of three particle types: the hollow spheroids with sizes about hundreds of micrometers (magnetite), the particles with sizes up to 100 μm from the porous material of sintered submicron particles (hematite), and nanoscale particles (ε-phase). We found that at the higher oxygen concentration the content of ε-Fe2O3 is increased up to ~50% at the same time with decreasing the Fe3O4 phase. The magnetic properties of the products are mainly determined by magnetite characteristics and are significantly reduced with decreasing its content in the powder. In order to investigate the synthesized ε-Fe2O3 on the ability to absorb the electromagnetic radiation in the millimeter wavelength range, we separated the product with the higher ε-phase concentration. The fraction mainly, consisting of ε-Fe2O3, showed the occurrence of the natural resonance at frequencies of 8.3 GHz and 130 GHz.

  10. Solar, Stellar and Galactic Connections between Particle Physics and Astrophysics

    CERN Document Server

    Carraminana, Alberto

    2007-01-01

    This book collects extended and specialized reviews on topics linking astrophysics and particle physics at a level intermediate between a graduate student and a young researcher. The book includes also three reviews on observational techniques used in forefront astrophysics and short articles on research performed in Latin America. The reviews, updated and written by specialized researchers, describe the state of the art in the related research topics. This book is a valuable complement not only for research but also for lecturers in specialized course of high energy astrophysics, cosmic ray astrophysics and particle physics.

  11. Final Report. Hydrodynamics by high-energy-density plasma flow and hydrodynamics and radiative hydrodynamics with astrophysical application

    International Nuclear Information System (INIS)

    OAK-B135 This is the final report from the project Hydrodynamics by High-Energy-Density Plasma Flow and Hydrodynamics and Radiation Hydrodynamics with Astrophysical Applications. This project supported a group at the University of Michigan in the invention, design, performance, and analysis of experiments using high-energy-density research facilities. The experiments explored compressible nonlinear hydrodynamics, in particular at decelerating interfaces, and the radiation hydrodynamics of strong shock waves. It has application to supernovae, astrophysical jets, shock-cloud interactions, and radiative shock waves

  12. ZAPP: The Z Astrophysical Plasma Properties collaborationa)

    Science.gov (United States)

    Rochau, G. A.; Bailey, J. E.; Falcon, R. E.; Loisel, G. P.; Nagayama, T.; Mancini, R. C.; Hall, I.; Winget, D. E.; Montgomery, M. H.; Liedahl, D. A.

    2014-05-01

    The Z Facility at Sandia National Laboratories [Matzen et al., Phys. Plasmas 12, 055503 (2005)] provides MJ-class x-ray sources that can emit powers >0.3 PW. This capability enables benchmark experiments of fundamental material properties in radiation-heated matter at conditions previously unattainable in the laboratory. Experiments on Z can produce uniform, long-lived, and large plasmas with volumes up to 20 cc, temperatures from 1-200 eV, and electron densities from 1017-23 cc-1. These unique characteristics and the ability to radiatively heat multiple experiments in a single shot have led to a new effort called the Z Astrophysical Plasma Properties (ZAPP) collaboration. The focus of the ZAPP collaboration is to reproduce the radiation and material characteristics of astrophysical plasmas as closely as possible in the laboratory and use detailed spectral measurements to strengthen models for atoms in plasmas. Specific issues under investigation include the LTE opacity of iron at stellar-interior conditions, photoionization around active galactic nuclei, the efficiency of resonant Auger destruction in black-hole accretion disks, and H-Balmer line shapes in white dwarf photospheres.

  13. Black Hole Astrophysics The Engine Paradigm

    CERN Document Server

    Meier, David L

    2012-01-01

    As a result of significant research over the past 20 years, black holes are now linked to some of the most spectacular and exciting phenomena in the Universe, ranging in size from those that have the same mass as stars to the super-massive objects that lie at the heart of most galaxies, including our own Milky Way. This book first introduces the properties of simple isolated holes, then adds in complications like rotation, accretion, radiation, and magnetic fields, finally arriving at a basic understanding of how these immense engines work. Black Hole Astrophysics • reviews our current knowledge of cosmic black holes and how they generate the most powerful observed pheonomena in the Universe; • highlights the latest, most up-to-date theories and discoveries in this very active area of astrophysical research; • demonstrates why we believe that black holes are responsible for important phenomena such as quasars, microquasars and gammaray bursts; • explains to the reader the nature of the violent and spe...

  14. Highlights of the NASA particle astrophysics program

    Energy Technology Data Exchange (ETDEWEB)

    Jones, William Vernon, E-mail: w.vernon.jones@nasa.gov [Astrophysics Division DH000, Science Mission Directorate, NASA Headquarters, Washington DC (United States)

    2014-07-01

    The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2015. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory. (author)

  15. Astrophysical Boundary Layers: A New Picture

    Science.gov (United States)

    Belyaev, Mikhail; Rafikov, Roman R.; Mclellan Stone, James

    2016-04-01

    Accretion is a ubiquitous process in astrophysics. In cases when the magnetic field is not too strong and a disk is formed, accretion can proceed through the mid plane all the way to the surface of the central compact object. Unless that compact object is a black hole, a boundary layer will be formed where the accretion disk touches its surfaces. The boundary layer is both dynamically and observationally significant as up to half of the accretion energy is dissipated there.Using a combination of analytical theory and computer simulations we show that angular momentum transport and accretion in the boundary layer is mediated by waves. This breaks with the standard astrophysical paradigm of an anomalous turbulent viscosity that drives accretion. However, wave-mediated angular momentum transport is a natural consequence of "sonic instability." The sonic instability, which we describe analytically and observe in our simulations, is a close cousin of the Papaloizou-Pringle instability. However, it is very vigorous in the boundary layer due to the immense radial velocity shear present at the equator.Our results are applicable to accreting neutron stars, white dwarfs, protostars, and protoplanets.

  16. Advancing Astrophysics with the Square Kilometre Array

    CERN Document Server

    Fender, Rob; Govoni, Federica; Green, Jimi; Hoare, Melvin; Jarvis, Matt; Johnston-Hollitt, Melanie; Keane, Evan; Koopmans, Leon; Kramer, Michael; Maartens, Roy; Macquart, Jean-Pierre; Mellema, Garrelt; Oosterloo, Tom; Prandoni, Isabella; Pritchard, Jonathan; Santos, Mario; Seymour, Nick; Stappers, Ben; Staveley-Smith, Lister; Tian, Wen Wu; Umana, Grazia; Wagg, Jeff; Bourke, Tyler L; AASKA14

    2015-01-01

    In 2014 it was 10 years since the publication of the comprehensive ‘Science with the Square Kilometre Array’ book and 15 years since the first such volume appeared in 1999. In that time numerous and unexpected advances have been made in the fields of astronomy and physics relevant to the capabilities of the Square Kilometre Array (SKA). The SKA itself progressed from an idea to a developing reality with a baselined Phase 1 design (SKA1) and construction planned from 2017. To facilitate the publication of a new, updated science book, which will be relevant to the current astrophysical context, the meeting "Advancing Astrophysics with the Square Kilometre Array" was held in Giardina Naxos, Sicily. Articles were solicited from the community for that meeting to document the scientific advances enabled by the first phase of the SKA and those pertaining to future SKA deployments, with expected gains of 5 times the Phase 1 sensitivity below 350 MHz, about 10 times the Phase 1 sensitivity above 350 MHz and with f...

  17. Bubble chambers for experiments in nuclear astrophysics

    Science.gov (United States)

    DiGiovine, B.; Henderson, D.; Holt, R. J.; Raut, R.; Rehm, K. E.; Robinson, A.; Sonnenschein, A.; Rusev, G.; Tonchev, A. P.; Ugalde, C.

    2015-05-01

    A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with γ-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross-sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross-sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross-sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas targets. Also, the detector is virtually insensitive to the γ-ray beam itself, thus allowing us to detect only the products of the nuclear reaction of interest. The development and the operation as well as the advantages and disadvantages of the bubble chamber are discussed.

  18. Bubble chambers for experiments in nuclear astrophysics

    International Nuclear Information System (INIS)

    A bubble chamber has been developed to be used as an active target system for low energy nuclear astrophysics experiments. Adopting ideas from dark matter detection with superheated liquids, a detector system compatible with γ-ray beams has been developed. This detector alleviates some of the limitations encountered in standard measurements of the minute cross-sections of interest to stellar environments. While the astrophysically relevant nuclear reaction processes at hydrostatic burning temperatures are dominated by radiative captures, in this experimental scheme we measure the time-reversed processes. Such photodisintegrations allow us to compute the radiative capture cross-sections when transitions to excited states of the reaction products are negligible. Due to the transformation of phase space, the photodisintegration cross-sections are up to two orders of magnitude higher. The main advantage of the new target-detector system is a density several orders of magnitude higher than conventional gas targets. Also, the detector is virtually insensitive to the γ-ray beam itself, thus allowing us to detect only the products of the nuclear reaction of interest. The development and the operation as well as the advantages and disadvantages of the bubble chamber are discussed

  19. Highlights of the NASA particle astrophysics program

    International Nuclear Information System (INIS)

    The NASA Particle Astrophysics Program covers Origin of the Elements, Nearest Sources of Cosmic Rays, How Cosmic Particle Accelerators Work, The Nature of Dark Matter, and Neutrino Astrophysics. Progress in each of these topics has come from sophisticated instrumentation flown on long duration balloon (LDB) flights around Antarctica over the past two decades. New opportunities including Super Pressure Balloons (SPB) and International Space Station (ISS) platforms are emerging for the next major step. Stable altitudes and long durations enabled by SPB flights ensure ultra-long duration balloon (ULDB) missions that can open doors to new science opportunities. The Alpha Magnetic Spectrometer (AMS) has been operating on the ISS since May 2011. The CALorimetric Electron Telescope (CALET) and Cosmic Ray Energetics And Mass (CREAM) experiments are being developed for launch to the Japanese Experiment Module Exposed Facility (JEM-EF) in 2015. And, the Extreme Universe Space Observatory (EUSO) is planned for launch to the ISS JEM-EF after 2017. Collectively, these four complementary ISS missions covering a large portion of the cosmic ray energy spectrum serve as a cosmic ray observatory. (author)

  20. Laboratory Astrophysics White Paper (based on the 2010 NASA Laboratory Astrophysics Workshop in Gatlinberg, Tennessee, 25-28 October 2010)

    OpenAIRE

    Savin, Daniel Wolf; Allamandola, Lou; Federman, Steve; Goldsmith, Paul; Kilbourne, Caroline; Oberg, Karin; Schultz, David; Weaver, Susanna Widicus; Ji, Hantao; Remington, Bruce

    2011-01-01

    The purpose of the 2010 NASA Laboratory Astrophysics Workshop (LAW) was, as given in the Charter from NASA, "to provide a forum within which the scientific community can review the current state of knowledge in the field of Laboratory Astrophysics, assess the critical data needs of NASA's current and future Space Astrophysics missions, and identify the challenges and opportunities facing the field as we begin a new decade". LAW 2010 was the fourth in a roughly quadrennial series of such works...

  1. Department of Plasma Dynamics

    International Nuclear Information System (INIS)

    The gas flow in high temperatures with regard to intensive heat transfer and chemical processes was investigated. The influence of flow rate of stabilizing gas on the electron concentration in plasma torch jet was studied. The microwave measurements of plasma parameters in middle pressure range and the time resolved measurements of the electron energy distribution in unstable plasma were carried out. A simple phase-sensitive microwave reflectometer for plasma diagnostics has been used for measuring the electron density in a positive column of glow discharge plasma in noble gases. The independance between energy conversion and charge distribution in the slender EGD channel was investigated. The discontinuities in electrogasdynamics were studied. (S.B.)

  2. High Time Resolution Astrophysics in the Extremely Large Telescope Era : White Paper

    CERN Document Server

    Shearer, Andy; Słowikowska, Aga; Barbieri, Cesare; Marsh, Tom; Dhillon, Vik; Mignani, Roberto; Dravins, Danis; Gouiffés, Christian; Mackay, Craig; Bonanno, Giovanni; Collins, Susan

    2010-01-01

    High Time Resolution Astrophysics (HTRA) concerns itself with observations on short scales normally defined as being lower than the conventional read-out time of a CCD. As such it is concerned with condensed objects such as neutron stars, black holes and white dwarfs, surfaces with extreme magnetic reconnection phenomena, as well as with planetary scale objects through transits and occultations. HTRA is the only way to make a major step forward in our understanding of several important astrophysical and physical processes; these include the extreme gravity conditions around neutron stars and stable orbits around stellar mass black holes. Transits, involving fast timing, can give vital information on the size of, and satellites around exoplanets. In the realm of fundamental physics very interesting applications lie in the regime of ultra-high time resolution, where quantum-physical phenomena, currently studied in laboratory physics, may be explored. HTRA science covers the full gamut of observational optical/I...

  3. Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions

    CERN Document Server

    Paxton, Bill; Schwab, Josiah; Bauer, Evan B; Bildsten, Lars; Cantiello, Matteo; Dessart, Luc; Farmer, R; Hu, H; Langer, N; Townsend, R H D; Townsley, Dean M; Timmes, F X

    2015-01-01

    We substantially update the capabilities of the open-source software instrument Modules for Experiments in Stellar Astrophysics (MESA). MESA can now simultaneously evolve an interacting pair of differentially rotating stars undergoing transfer and loss of mass and angular momentum, greatly enhancing the prior ability to model binary evolution. New MESA capabilities in fully coupled calculation of nuclear networks with hundreds of isotopes now allow MESA to accurately simulate advanced burning stages needed to construct supernova progenitor models. Implicit hydrodynamics with shocks can now be treated with MESA, enabling modeling of the entire massive star lifecycle, from pre-main sequence evolution to the onset of core collapse and nucleosynthesis from the resulting explosion. Coupling of the GYRE non-adiabatic pulsation instrument with MESA allows for new explorations of the instability strips for massive stars while also accelerating the astrophysical use of asteroseismology data. We improve treatment of ma...

  4. Statistical learning in high energy and astrophysics

    International Nuclear Information System (INIS)

    This thesis studies the performance of statistical learning methods in high energy and astrophysics where they have become a standard tool in physics analysis. They are used to perform complex classification or regression by intelligent pattern recognition. This kind of artificial intelligence is achieved by the principle ''learning from examples'': The examples describe the relationship between detector events and their classification. The application of statistical learning methods is either motivated by the lack of knowledge about this relationship or by tight time restrictions. In the first case learning from examples is the only possibility since no theory is available which would allow to build an algorithm in the classical way. In the second case a classical algorithm exists but is too slow to cope with the time restrictions. It is therefore replaced by a pattern recognition machine which implements a fast statistical learning method. But even in applications where some kind of classical algorithm had done a good job, statistical learning methods convinced by their remarkable performance. This thesis gives an introduction to statistical learning methods and how they are applied correctly in physics analysis. Their flexibility and high performance will be discussed by showing intriguing results from high energy and astrophysics. These include the development of highly efficient triggers, powerful purification of event samples and exact reconstruction of hidden event parameters. The presented studies also show typical problems in the application of statistical learning methods. They should be only second choice in all cases where an algorithm based on prior knowledge exists. Some examples in physics analyses are found where these methods are not used in the right way leading either to wrong predictions or bad performance. Physicists also often hesitate to profit from these methods because they fear that statistical learning methods cannot be controlled in a

  5. Trojan Horse Method: recent applications in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Spitaleri, C.; Cherubini, S.; La Cognata, M.; Lamia, L. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Mukhamedzhanov, A. [Cyclotron Institute, Texas A and M University, College Station, Texas (United States); Pizzone, R.G.; Romano, S.; Sergi, M.L. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Tumino, A. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Universita degli Studi di Enna ' Kore' , Enna (Italy)

    2010-03-01

    The Trojan Horse Method (THM) is a powerful indirect technique to extract the bare nucleus cross section (or equivalently the bare nucleus astrophysical factor) for astrophysically relevant reactions. The theory has been discussed in many works in relation to the different types of reactions studied. Here we present the methodology to select the quasi free mechanism in order to extract this important parameter.

  6. Cosmology and Fundamental Physics and their Laboratory Astrophysics Connections

    OpenAIRE

    Haxton, W. C.

    2011-01-01

    The Decadal Survey of Astronomy and Astrophysics created five panels to identify the science themes that would define the field's research frontiers in the coming decade. I will describe the conclusions of one of these, the Panel on Cosmology and Fundamental Physics, and comment on their relevance to the discussions at this meeting of the NASA Laboratory Astrophysics community.

  7. Nuclear Astrophysics from View Point of Few-Body Problems

    International Nuclear Information System (INIS)

    Few-body systems provide very useful tools to solve different problems for nuclear astrophysics. This is the case of indirect techniques, developed to overcome some of the limits of direct measurements at astrophysical energies. Here the Coulomb dissociation, the asymptotic normalization coefficient and the Trojan Horse method are discussed. (author)

  8. Resolving astrophysical uncertainties in dark matter direct detection

    DEFF Research Database (Denmark)

    Frandsen, Mads Toudal; Kahlhoefer, Felix; McCabe, Christopher;

    2012-01-01

    We study the impact of the assumed velocity distribution of galactic dark matter particles on the interpretation of results from nuclear recoil detectors. By converting experimental data to variables that make the astrophysical unknowns explicit, different experiments can be compared without...... modulation fraction. However constraints from CDMS and XENON cannot be evaded by appealing to such astrophysical uncertainties alone....

  9. The MICA Experiment: Astrophysics in Virtual Worlds

    CERN Document Server

    Djorgovski, S G; Knop, Rob; Longo, Giuseppe; McMillan, Steve; Vesperini, Enrico; Donalek, Ciro; Graham, Matthew; Mahabal, Asish; Sauer, Franz; White, Charles; Lopes, Crista

    2013-01-01

    We describe the work of the Meta-Institute for Computational Astrophysics (MICA), the first professional scientific organization based in virtual worlds. MICA was an experiment in the use of this technology for science and scholarship, lasting from the early 2008 to June 2012, mainly using the Second Life and OpenSimulator as platforms. We describe its goals and activities, and our future plans. We conducted scientific collaboration meetings, professional seminars, a workshop, classroom instruction, public lectures, informal discussions and gatherings, and experiments in immersive, interactive visualization of high-dimensional scientific data. Perhaps the most successful of these was our program of popular science lectures, illustrating yet again the great potential of immersive VR as an educational and outreach platform. While the members of our research groups and some collaborators found the use of immersive VR as a professional telepresence tool to be very effective, we did not convince a broader astrophy...

  10. Astrophysical life extinctions what killed the dinosaurs?

    CERN Document Server

    Dar, Arnon

    1999-01-01

    Geological records indicate that the exponential diversification of marine and continental life on Earth in the past 500 My was interrupted by many life extinctions. They also indicate that the major mass extinctions were correlated in time with large meteoritic impacts, gigantic volcanic eruptions, sea regressions and drastic changes in global climate. Some of these catastrophes coincided in time. The astrophysical life extinction mechanisms which were proposed so far, in particular, meteoritic impacts, nearby supernova explosions, passage through molecular or dark matter clouds, and Galactic gamma/cosmic ray bursts cannot explain the time coincidences between these catastrophes. However, recent observations suggest that many planetary-mass objects may be present in the outer solar system between the Kuiper belt and the Oort cloud. Gravitational perturbations may occasionally bring them into the inner solar system. Their passage near Earth could have generated gigantic tidal waves, large volcanic eruptions, ...

  11. General relativity with applications to astrophysics

    CERN Document Server

    Straumann, Norbert

    2004-01-01

    This text provides a comprehensive and timely introduction to general relativity The foundations of the theory in Part I are thoroughly developed together with the required mathematical background from differential geometry in Part III The six chapters in Part II are devoted to tests of general relativity and to many of its applications Binary pulsars are studied in considerable detail Much space is devoted to the study of compact objects, especially to black holes This includes a detailed derivation of the Kerr solution, Israel's proof of his uniqueness theorem, and derivations of the basic laws of black hole physics The final chapter of this part contains Witten's proof of the positive energy theorem The book addresses undergraduate and graduate students in physics, astrophysics and mathematics It is very well structured and should become a standard text for a modern treatment of gravitational physics The clear presentation of differential geometry makes it also useful for string theory and other fields of ...

  12. Practices in source code sharing in astrophysics

    CERN Document Server

    Shamir, Lior; Allen, Alice; Berriman, Bruce; Teuben, Peter; Nemiroff, Robert J; Mink, Jessica; Hanisch, Robert J; DuPrie, Kimberly

    2013-01-01

    While software and algorithms have become increasingly important in astronomy, the majority of authors who publish computational astronomy research do not share the source code they develop, making it difficult to replicate and reuse the work. In this paper we discuss the importance of sharing scientific source code with the entire astrophysics community, and propose that journals require authors to make their code publicly available when a paper is published. That is, we suggest that a paper that involves a computer program not be accepted for publication unless the source code becomes publicly available. The adoption of such a policy by editors, editorial boards, and reviewers will improve the ability to replicate scientific results, and will also make the computational astronomy methods more available to other researchers who wish to apply them to their data.

  13. New Prospects in High Energy Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Blandford, Roger; /KIPAC, Menlo Park

    2011-11-15

    Recent discoveries using TeV, X-ray and radio telescopes as well as Ultra High Energy Cosmic Ray arrays are leading to new insights into longstanding puzzles in high energy astrophysics. Many of these insights come from combining observations throughout the electromagnetic and other spectra as well as evidence assembled from different types of source to propose general principles. Issues discussed in this general overview include methods of accelerating relativistic particles, and amplifying magnetic field, the dynamics of relativistic outflows and the nature of the prime movers that power them. Observational approaches to distinguishing hadronic, leptonic and electromagnetic outflows and emission mechanisms are discussed along with probes of the velocity field and the confinement mechanisms. Observations with GLAST promise to be very prescriptive for addressing these problems.

  14. Astrocladistics: Multivariate Evolutionary Analysis in Astrophysics

    CERN Document Server

    Fraix-Burnet, Didier

    2010-01-01

    The Hubble tuning fork diagram, based on morphology and established in the 1930s, has always been the preferred scheme for classification of galaxies. However, the current large amount of data up to higher and higher redshifts asks for more sophisticated statistical approaches like multivariate analyses. Clustering analyses are still very confidential, and do not take into account the unavoidable characteristics in our Universe: evolution. Assuming branching evolution of galaxies as a 'transmission with modification', we have shown that the concepts and tools of phylogenetic systematics (cladistics) can be heuristically transposed to the case of galaxies. This approach that we call "astrocladistics", has now successfully been applied on several samples of galaxies and globular clusters. Maximum parsimony and distance-based approaches are the most popular methods to produce phylogenetic trees and, like most other studies, we had to discretize our variables. However, since astrophysical data are intrinsically c...

  15. Environmental Effects for Gravitational-wave Astrophysics

    CERN Document Server

    Barausse, Enrico; Pani, Paolo

    2014-01-01

    The upcoming detection of gravitational waves by terrestrial interferometers will usher in the era of gravitational-wave astronomy. This will be particularly true when space-based detectors will come of age and measure the mass and spin of massive black holes with exquisite precision and up to very high redshifts, thus allowing for better understanding of the symbiotic evolution of black holes with galaxies, and for high-precision tests of General Relativity in strong-field, highly-dynamical regimes. Such ambitious goals require that astrophysical environmental pollution of gravitational-wave signals be constrained to negligible levels, so that neither detection nor estimation of the source parameters are significantly affected. Here, we consider the main sources for space-based detectors -the inspiral, merger and ringdown of massive black-hole binaries and extreme mass-ratio inspirals- and account for various effects on their gravitational waveforms, including electromagnetic fields, cosmological evolution, ...

  16. Theoretically Palatable Flavor Combinations of Astrophysical Neutrinos.

    Science.gov (United States)

    Bustamante, Mauricio; Beacom, John F; Winter, Walter

    2015-10-16

    The flavor composition of high-energy astrophysical neutrinos can reveal the physics governing their production, propagation, and interaction. The IceCube Collaboration has published the first experimental determination of the ratio of the flux in each flavor to the total. We present, as a theoretical counterpart, new results for the allowed ranges of flavor ratios at Earth for arbitrary flavor ratios in the sources. Our results will allow IceCube to more quickly identify when their data imply standard physics, a general class of new physics with arbitrary (incoherent) combinations of mass eigenstates, or new physics that goes beyond that, e.g., with terms that dominate the Hamiltonian at high energy. PMID:26550861

  17. Relativistic astrophysics and cosmology a primer

    CERN Document Server

    Hoyng, Peter

    2006-01-01

    This book offers a succinct and self-contained treatment of general relativity and its application to neutron stars, black holes, gravitational waves and cosmology, at an intermediate level. The required mathematical concepts are introduced informally, following geometrical intuition as much as possible. The approach is theoretical, but there is ample discussion of observational aspects and instrumental issues where appropriate. Topical issues such as the Gravity Probe B mission, and the physics of interferometer detectors of gravitational waves and the angular power spectrum of the Cosmic Microwave Background are included. The book is written for advanced undergraduates and beginning graduate students in (astro)physics. The reader is assumed to be familiar with linear algebra and analysis, ordinary differential equations, special relativity, and basic thermal physics, but prior knowledge of differential geometry and general relativity is not required. Containing 140 exercises with extensive hints for their s...

  18. Sc III Spectral Properties of Astrophysical Interest

    CERN Document Server

    Nandy, D K; Sahoo, B K; Li, Chengbin

    2011-01-01

    Transition properties such as oscillator strengths, transition rates, branching ratios and lifetimes of many low-lying states in the doubly ionized scandium (Sc III) are reported. A relativistic method in the coupled-cluster framework has been employed to incorporate the electron correlations due to the Coulomb interaction to all orders by considering all possible singly and doubly excited electronic configurations conjointly with the contributions from the leading order triple excitations in a perturbative approach. Present results are compared with the previously available results for the transition lines of astrophysical interest and the role of the correlation effects are also discussed concisely. Some of the transition rates, oscillator strengths and lifetimes are acquainted.

  19. Nuclear Astrophysics at IFIN-HH

    Science.gov (United States)

    Livius, Trache

    2016-04-01

    I will present the possibilities and some results of doing nuclear astrophysics research in IFIN-HH Bucharest-Magurele. There are basically two lines of experimental activities: (1) direct measurements with beams from the local accelerators, in particular with the new 3 MV Tandetron accelerator. This facility turns out to be competitive for reactions induced by a-particles and light ions. Extra capabilities are given by the ultra-low background laboratory we have in a salt mine about 2.5 hrs. driving north of Bucharest; (2) indirect measurements done with beams at international facilities, in particular at those providing Rare Ion Beams. Completely new and unique opportunities will be provided by ELI-NP, under construction in our institute.

  20. Studies of High Energy Particle Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Nitz, David F [Michigan Technological University; Fick, Brian E [Michigan Technological University

    2014-07-30

    This report covers the progress of the Michigan Technological University particle astrophysics group during the period April 15th, 2011 through April 30th, 2014. The principal investigator is Professor David Nitz. Professor Brian Fick is the Co-PI. The focus of the group is the study of the highest energy cosmic rays using the Pierre Auger Observatory. The major goals of the Pierre Auger Observatory are to discover and understand the source or sources of cosmic rays with energies exceeding 10**19 eV, to identify the particle type(s), and to investigate the interactions of those cosmic particles both in space and in the Earth's atmosphere. The Pierre Auger Observatory in Argentina was completed in June 2008 with 1660 surface detector stations and 24 fluorescence telescopes arranged in 4 stations. It has a collecting area of 3,000 square km, yielding an aperture of 7,000 km**2 sr.

  1. New isotopes of interest to astrophysics

    CERN Document Server

    Davids, C N; Pardo, R C; Parks, L A

    1976-01-01

    The beta decays of the new isotopes /sup 53/Ti and /sup 59/Mn have been studied. These neutron-rich isotopes have half-lives of 32.7+or-0.9 s and 4.75+or-0.14 s, respectively. They were produced via the /sup 48/Ca(/sup 7/Li, pn)/sup 53/Ti and /sup 48/Ca(/sup 13/C, pn) /sup 59/Mn reactions using beams from the Argonne National Laboratory FN Tandem Van de Graaff accelerator. Measurement of gamma singles, gamma - gamma coincidences, and beta - gamma coincidences were facilitated by a pneumatic target-transfer system ('rabbit'). Decay schemes are presented, and the measured masses compared with various predictions. The relevance to astrophysics will be discussed. In addition, a new 8-target multiple rabbit system will be described. (7 refs).

  2. Few-body models for nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Descouvemont, P., E-mail: pdesc@ulb.ac.be [Physique Nucléaire Théorique et Physique Mathématique, C.P. 229, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Baye, D., E-mail: dbaye@ulb.ac.be [Physique Nucléaire Théorique et Physique Mathématique, C.P. 229, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Quantique, C.P. 165/82, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Suzuki, Y., E-mail: suzuki@nt.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); RIKEN Nishina Center, Wako 351-0198 (Japan); Aoyama, S., E-mail: aoyama@cc.niigata-u.ac.jp [Center for Academic Information Service, Niigata University, Niigata 950-2181 (Japan); Arai, K., E-mail: arai@nagaoka-ct.ac.jp [Division of General Education, Nagaoka National College of Technology, 888 Nishikatakai, Nagaoka, Niigata 940-8532 (Japan)

    2014-04-15

    We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the {sup 2}H(d, γ){sup 4}He, {sup 2}H(d, p){sup 3}H and {sup 2}H(d, n){sup 3}He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.

  3. Few-body models for nuclear astrophysics

    Directory of Open Access Journals (Sweden)

    P. Descouvemont

    2014-02-01

    Full Text Available We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the 2H(d, γ4He, 2H(d, p3H and 2H(d, n3He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.

  4. Nuclear astrophysics with radioactive ions at FAIR

    CERN Document Server

    Reifarth, R; Göbel, K; Heftrich, T; Heil, M; Koloczek, A; Langer, C; Plag, R; Pohl, M; Sonnabend, K; Weigand, M; Adachi, T; Aksouh, F; Al-Khalili, J; AlGarawi, M; AlGhamdi, S; Alkhazov, G; Alkhomashi, N; Alvarez-Pol, H; Alvarez-Rodriguez, R; Andreev, V; Andrei, B; Atar, L; Aumann, T; Avdeichikov, V; Bacri, C; Bagchi, S; Barbieri, C; Beceiro, S; Beck, C; Beinrucker, C; Belier, G; Bemmerer, D; Bendel, M; Benlliure, J; Benzoni, G; Berjillos, R; Bertini, D; Bertulani, C; Bishop, S; Blasi, N; Bloch, T; Blumenfeld, Y; Bonaccorso, A; Boretzky, K; Botvina, A; Boudard, A; Boutachkov, P; Boztosun, I; Bracco, A; Brambilla, S; Monago, J Briz; Caamano, M; Caesar, C; Camera, F; Casarejos, E; Catford, W; Cederkall, J; Cederwall, B; Chartier, M; Chatillon, A; Cherciu, M; Chulkov, L; Coleman-Smith, P; Cortina-Gil, D; Crespi, F; Crespo, R; Cresswell, J; Csatlós, M; Déchery, F; Davids, B; Davinson, T; Derya, V; Detistov, P; Fernandez, P Diaz; DiJulio, D; Dmitry, S; Doré, D; nas, J Due\\; Dupont, E; Egelhof, P; Egorova, I; Elekes, Z; Enders, J; Endres, J; Ershov, S; Ershova, O; Fernandez-Dominguez, B; Fetisov, A; Fiori, E; Fomichev, A; Fonseca, M; Fraile, L; Freer, M; Friese, J; Borge, M G; Redondo, D Galaviz; Gannon, S; Garg, U; Gasparic, I; Gasques, L; Gastineau, B; Geissel, H; Gernhäuser, R; Ghosh, T; Gilbert, M; Glorius, J; Golubev, P; Gorshkov, A; Gourishetty, A; Grigorenko, L; Gulyas, J; Haiduc, M; Hammache, F; Harakeh, M; Hass, M; Heine, M; Hennig, A; Henriques, A; Herzberg, R; Holl, M; Ignatov, A; Ignatyuk, A; Ilieva, S; Ivanov, M; Iwasa, N; Jakobsson, B; Johansson, H; Jonson, B; Joshi, P; Junghans, A; Jurado, B; Körner, G; Kalantar, N; Kanungo, R; Kelic-Heil, A; Kezzar, K; Khan, E; Khanzadeev, A; Kiselev, O; Kogimtzis, M; Körper, D; Kräckmann, S; Kröll, T; Krücken, R; Krasznahorkay, A; Kratz, J; Kresan, D; Krings, T; Krumbholz, A; Krupko, S; Kulessa, R; Kumar, S; Kurz, N; Kuzmin, E; Labiche, M; Langanke, K; Lazarus, I; Bleis, T Le; Lederer, C; Lemasson, A; Lemmon, R; Liberati, V; Litvinov, Y; Löher, B; Herraiz, J Lopez; Münzenberg, G; Machado, J; Maev, E; Mahata, K; Mancusi, D; Marganiec, J; Perez, M Martinez; Marusov, V; Mengoni, D; Million, B; Morcelle, V; Moreno, O; Movsesyan, A; Nacher, E; Najafi, M; Nakamura, T; Naqvi, F; Nikolski, E; Nilsson, T; Nociforo, C; Nolan, P; Novatsky, B; Nyman, G; Ornelas, A; Palit, R; Pandit, S; Panin, V; Paradela, C; Parkar, V; Paschalis, S; Paw\\lowski, P; Perea, A; Pereira, J; Petrache, C; Petri, M; Pickstone, S; Pietralla, N; Pietri, S; Pivovarov, Y; Potlog, P; Prokofiev, A; Rastrepina, G; Rauscher, T; Ribeiro, G; Ricciardi, M; Richter, A; Rigollet, C; Riisager, K; Rios, A; Ritter, C; Frutos, T Rodríguez; Vignote, J Rodriguez; Röder, M; Romig, C; Rossi, D; Roussel-Chomaz, P; Rout, P; Roy, S; Söderström, P; Sarkar, M Saha; Sakuta, S; Salsac, M; Sampson, J; Saez, J Sanchez del Rio; Rosado, J Sanchez; Sanjari, S; Sarriguren, P; Sauerwein, A; Savran, D; Scheidenberger, C; Scheit, H; Schmidt, S; Schmitt, C; Schnorrenberger, L; Schrock, P; Schwengner, R; Seddon, D; Sherrill, B; Shrivastava, A; Sidorchuk, S; Silva, J; Simon, H; Simpson, E; Singh, P; Slobodan, D; Sohler, D; Spieker, M; Stach, D; Stan, E; Stanoiu, M; Stepantsov, S; Stevenson, P; Strieder, F; Stuhl, L; Suda, T; Sümmerer, K; Streicher, B; Taieb, J; Takechi, M; Tanihata, I; Taylor, J; Tengblad, O; Ter-Akopian, G; Terashima, S; Teubig, P; Thies, R; Thoennessen, M; Thomas, T; Thornhill, J; Thungstrom, G; Timar, J; Togano, Y; Tomohiro, U; Tornyi, T; Tostevin, J; Townsley, C; Trautmann, W; Trivedi, T; Typel, S; Uberseder, E; Udias, J; Uesaka, T; Uvarov, L; Vajta, Z; Velho, P; Vikhrov, V; Volknandt, M; Volkov, V; von Neumann-Cosel, P; von Schmid, M; Wagner, A; Wamers, F; Weick, H; Wells, D; Westerberg, L; Wieland, O; Wiescher, M; Wimmer, C; Wimmer, K; Winfield, J S; Winkel, M; Woods, P; Wyss, R; Yakorev, D; Yavor, M; Cardona, J Zamora; Zartova, I; Zerguerras, T; Zgura, I; Zhdanov, A; Zhukov, M; Zieblinski, M; Zilges, A; Zuber, K

    2016-01-01

    The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process beta-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes.

  5. Astrophysics and the evolution of the universe

    CERN Document Server

    Kisslinger, Leonard S

    2014-01-01

    The aim of this book is to teach undergraduate college or university students the basic physics concepts needed to understand the mathematics which describes the evolution of the universe, and based on this to teach the astrophysical theories behind evolution from very early times to the present. The book does not require students to have extensive knowledge of mathematics, like calculus, and includes material that explains concepts such as velocity, acceleration, and force. Based on this, fascinating topics such as Dark Matter, measuring Dark Energy via supernovae velocities, and the creation of mass via the Higgs mechanism are explained. All college students with an interest in science, especially astronomy, without extensive mathematical backgrounds should be able to use and learn from this book. Adults interested in topics like dark energy and the Higgs boson, which are in the news, can make use of this book as well.

  6. Relativistic Astrophysics and Cosmology: A Primer

    Energy Technology Data Exchange (ETDEWEB)

    Abramowicz, Marek A [Department of Astronomy and Astrophysics, Chalmers University of Technology, 41296 Goeteborg (Sweden)

    2007-10-21

    'Relativistic Astrophysics and Cosmology: A Primer' by Peter Hoyng, was published last year by Springer. The book is based on lectures given by the author at University of Utrecht to advanced undergraduates. This is a short and scholarly book. In about 300 pages, the author has covered the most interesting and important applications of Albert Einstein's general relativity in present-day astrophysics and cosmology: black holes, neutron stars, gravitational waves, and the cosmic microwave background. The book stresses theory, but also discusses several experimental and observational topics, such as the Gravity Probe B mission, interferometer detectors of gravitational waves and the power spectrum of the cosmic microwave background. The coverage is not uniform. Some topics are discussed in depth, others are only briefly mentioned. The book obviously reflects the author's own research interests and his preferences for specific mathematical methods, and the choice of the original artwork that illustrates the book (and appears on its cover) is a very personal one. I consider this personal touch an advantage, even if I do not always agree with the author's choices. For example, I employ Killing vectors as a very useful mathematical tool not only in my research on black holes, but also in my classes. I find that my students prefer it when discussions of particle, photon and fluid motion in the Schwarzschild and Kerr spacetimes are based explicitly and directly on the Killing vectors rather than on coordinate calculations. The latter approach is, of course, the traditional one, and is used in Peter Hoyng's book. Reading the book is a stimulating experience, because the reader can almost feel the author's presence. The author's opinions, his mathematical taste, his research pleasures, and his pedagogical passion are apparent everywhere. Lecturers contemplating a new course on relativistic astrophysics could adopt Hoyng's book as

  7. Transient dynamics of perturbations in astrophysical disks

    CERN Document Server

    Razdoburdin, Dmitry N

    2015-01-01

    This paper reviews some aspects of one of the major unsolved problems in understanding astrophysical (in particular, accretion) disks: whether the disk interiors may be effectively viscous in spite of the absence of marnetorotational instability? In this case a rotational homogeneous inviscid flow with a Keplerian angular velocity profile is spectrally stable, making the transient growth of perturbations a candidate mechanism for energy transfer from the regular motion to perturbations. Transient perturbations differ qualitatively from perturbation modes and can grow substantially in shear flows due to the nonnormality of their dynamical evolution operator. Since the eigenvectors of this operator, alias perturbation modes, are mutually nonorthogonal, they can mutually interfere, resulting in the transient growth of their linear combinations. Physically, a growing transient perturbation is a leading spiral whose branches are shrunk as a result of the differential rotation of the flow. This paper discusses in d...

  8. Precision Stellar Astrophysics in the Kepler Era

    CERN Document Server

    Huber, Daniel

    2016-01-01

    The study of fundamental properties (such as temperatures, radii, masses, and ages) and interior processes (such as convection and angular momentum transport) of stars has implications on various topics in astrophysics, ranging from the evolution of galaxies to understanding exoplanets. In this contribution I will review the basic principles of two key observational methods for constraining fundamental and interior properties of single field stars: the study stellar oscillations (asteroseismology) and optical long-baseline interferometry. I will highlight recent breakthrough discoveries in asteroseismology such as the measurement of core rotation rates in red giants and the characterization of exoplanet systems. I will furthermore comment on the reliability of interferometry as a tool to calibrate indirect methods to estimate fundamental properties, and present a new angular diameter measurement for the exoplanet host star HD219134 which demonstrates that diameters for stars which are relatively well resolved...

  9. Protection of the Guillermo Haro Astrophysical Observatory

    Science.gov (United States)

    Carrasco, E.; Carraminana, A. P.

    The Guillermo Haro Astrophysical Observatory, with a 2m telescope, is one of only two professional observatories in Mexico. The observatory, run by the InstitutoNacional de Astrofisica, Optica y Electronica (INAOE), is located in the north of Mexico, in Cananea, Sonora. Since 1995 the observatory has faced the potential threat of pollution by an open cast mine to be opened at 3kms from the observatory. In the absence of national or regional laws enforcing protection to astronomical sites in Mexico, considerable effort has been needed to guarantee the conditions of the site. We present the studies carried out to ensure the protection of the Guillermo Haro Observatory from pollution due to dust, light and vibrations.

  10. Astrophysics of Dust in Cold Clouds

    CERN Document Server

    Draine, B T

    2003-01-01

    Nine lectures reviewing the astrophysics of dust in interstellar clouds. Topics include: (1) Summary of observational evidence concerning interstellar dust: broadband extinction, scattering of starlight, polarization of starlight, spectroscopy of dust, IR and FIR emission, and depletions of grain-forming elements. (2) Optics of interstellar dust grains: dielectric functions of nonconducting and conducting materials, calculational techniques, formulae valid in the Rayleigh limit, Kramers-Kronig relations, microwave emission mechanisms, and X-ray scattering. (3) IR and FIR emission: heating of interstellar dust, including single-photon heating, and resulting IR emission spectrum. (4) Charging of dust grains: collisional charging, photoelectric emission, and resulting charge distribution functions. (5) Dynamics: gas drag, Lorentz force, forces due to anisotropic radiation, and resulting drift velocities. (6) Rotational dynamics: brownian rotation, suprathermal rotation, and effects of starlight torques. (7) Alig...

  11. MPI-AMRVAC for Solar and Astrophysics

    CERN Document Server

    Porth, O; Hendrix, T; Moschou, S P; Keppens, R

    2014-01-01

    In this paper we present an update on the open source MPI-AMRVAC simulation toolkit where we focus on solar- and non-relativistic astrophysical magneto-fluid dynamics. We highlight recent developments in terms of physics modules such as hydrodynamics with dust coupling and the conservative implementation of Hall magnetohydrodynamics. A simple conservative high-order finite difference scheme that works in combination with all available physics modules is introduced and demonstrated at the example of monotonicity preserving fifth order reconstruction. Strong stability preserving high order Runge-Kutta time steppers are used to obtain stable evolutions in multidimensional applications realizing up to fourth order accuracy in space and time. With the new distinction between active and passive grid cells, MPI-AMRVAC is ideally suited to simulate evolutions where parts of the solution are controlled analytically, or have a tendency to progress into or out of a stationary state. Typical test problems and representat...

  12. Foreword: Advanced Science Letters (ASL), Special Issue on Computational Astrophysics

    CERN Document Server

    ,

    2009-01-01

    Computational astrophysics has undergone unprecedented development over the last decade, becoming a field of its own. The challenge ahead of us will involve increasingly complex multi-scale simulations. These will bridge the gap between areas of astrophysics such as star and planet formation, or star formation and galaxy formation, that have evolved separately until today. A global knowledge of the physics and modeling techniques of astrophysical simulations is thus an important asset for the next generation of modelers. With the aim at fostering such a global approach, we present the Special Issue on Computational Astrophysics for the Advanced Science Letters (http://www.aspbs.com/science.htm). The Advanced Science Letters (ASL) is a new multi-disciplinary scientific journal which will cover extensively computational astrophysics and cosmology, and will act as a forum for the presentation and discussion of novel work attempting to connect different research areas. This Special Issue collects 9 reviews on 9 k...

  13. A general method of estimating stellar astrophysical parameters from photometry

    CERN Document Server

    Belikov, A N

    2008-01-01

    Applying photometric catalogs to the study of the population of the Galaxy is obscured by the impossibility to map directly photometric colors into astrophysical parameters. Most of all-sky catalogs like ASCC or 2MASS are based upon broad-band photometric systems, and the use of broad photometric bands complicates the determination of the astrophysical parameters for individual stars. This paper presents an algorithm for determining stellar astrophysical parameters (effective temperature, gravity and metallicity) from broad-band photometry even in the presence of interstellar reddening. This method suits the combination of narrow bands as well. We applied the method of interval-cluster analysis to finding stellar astrophysical parameters based on the newest Kurucz models calibrated with the use of a compiled catalog of stellar parameters. Our new method of determining astrophysical parameters allows all possible solutions to be located in the effective temperature-gravity-metallicity space for the star and se...

  14. Distance Correlation Methods for Discovering Associations in Large Astrophysical Databases

    CERN Document Server

    Martinez-Gomez, Elizabeth; Richards, Donald St P

    2013-01-01

    High-dimensional, large-sample astrophysical databases of galaxy clusters, such as the Chandra Deep Field South COMBO-17 database, provide measurements on many variables for thousands of galaxies and a range of redshifts. Current understanding of galaxy formation and evolution rests sensitively on relationships between different astrophysical variables; hence an ability to detect and verify associations or correlations between variables is important in astrophysical research. In this paper, we apply a recently defined statistical measure called the distance correlation coefficient which can be used to identify new associations and correlations between astrophysical variables. The distance correlation coefficient applies to variables of any dimension; it can be used to determine smaller sets of variables that provide equivalent astrophysical information; it is zero only when variables are independent; and it is capable of detecting nonlinear associations that are undetectable by the classical Pearson correlati...

  15. Test of Lorentz Violation with Astrophysical Neutrino Flavor

    CERN Document Server

    Katori, Teppei; Salvado, Jordi

    2016-01-01

    The high-energy astrophysical neutrinos recently discovered by IceCube opened a new way to test Lorentz and CPT violation through the astrophysical neutrino mixing properties. The flavor ratio of astrophysical neutrinos is a very powerful tool to investigate tiny effects caused by Lorentz and CPT violation. There are 3 main findings; (1) current limits on Lorentz and CPT violation in neutrino sector are not tight and they allow for any flavor ratios, (2) however, the observable flavor ratio on the Earth is tied with the flavor ratio at production, this means we can test both the presence of new physics and the astrophysical neutrino production mechanism simultaneously, and (3) the astrophysical neutrino flavor ratio is one of the most stringent tests of Lorentz and CPT violation.

  16. The CATSAT Student Explorer Mission

    OpenAIRE

    Forrest, D. J.; Levenson, K.; Vestrand, W. T.; Reister, K.; J. Smith; Wood, C.; Williams, C.; Whitford, C.; Watcon, D.; Owens, A.

    1996-01-01

    CATSAT (Cooperative Astrophysical and Technology SATellite) is one of three missions being developed under NASA/USRA's Student Explorer Demonstration Initiative (STEDI) for launch in 1997-98. STEDI is a pilot program to "assess the efficacy of smaller, low-cost spaceflight missions ... that is matched to the traditional process of research and development at universities". This program allows $4 million and 2-3 years for all aspects of the mission, i.e. instrument and satellite development, i...

  17. Investigating High Field Gravity using Astrophysical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Elliott D.; /SLAC

    2008-02-01

    The purpose of these lectures is to introduce particle physicists to astrophysical techniques. These techniques can help us understand certain phenomena important to particle physics that are currently impossible to address using standard particle physics experimental techniques. As the subject matter is vast, compromises are necessary in order to convey the central ideas to the reader. Many general references are included for those who want to learn more. The paragraphs below elaborate on the structure of these lectures. I hope this discussion will clarify my motivation and make the lectures easier to follow. The lectures begin with a brief review of more theoretical ideas. First, elements of general relativity are reviewed, concentrating on those aspects that are needed to understand compact stellar objects (white dwarf stars, neutron stars, and black holes). I then review the equations of state of these objects, concentrating on the simplest standard models from astrophysics. After these mathematical preliminaries, Sec. 2(c) discusses 'The End State of Stars'. Most of this section also uses the simplest standard models. However, as these lectures are for particle physicists, I also discuss some of the more recent approaches to the equation of state of very dense compact objects. These particle-physics-motivated equations of state can dramatically change how we view the formation of black holes. Section 3 focuses on the properties of the objects that we want to characterize and measure. X-ray binary systems and Active Galactic Nuclei (AGN) are stressed because the lectures center on understanding very dense stellar objects, black hole candidates (BHCs), and their accompanying high gravitational fields. The use of x-ray timing and gamma-ray experiments is also introduced in this section. Sections 4 and 5 review information from x-ray and gamma-ray experiments. These sections also discuss the current state of the art in x-ray and gamma-ray satellite

  18. Double layers and circuits in astrophysics

    International Nuclear Information System (INIS)

    As the rate of energy release in a double layer with voltage DeltaV is P corresponding to IDeltaV, a double layer must be treated part of a circuit which delivers the current I. As neither double layer nor circuit can be derived from magnetofluid models of a plasma, such models are useless for treating energy transfer by menas of double layers. They must be replaced by particle models and circuit theory. A simple circuit is suggested which is applied to the energizing of auroroal particles, to solar flares, and to intergalactic double radio sources. Application to the heliospheric current systems leads to the prediction of two double layers on the sun's axis which may give radiations detectable from earth. Double layers in space should be classified as a new type of celestial object (one example is the double radio sources). It is tentatively suggested in X-ray and gamma-ray bursts may be due to exploding double layers (although annihilation is an alternative energy source). A study of how a number of the most used textbooks in astrophysics treat important concepts like double layers, critical velocity, pinch effects and circuits is made. It is found that students using these textbooks remain essentially ignorant of even the existence of these, in spite of the fact that some of them have been well known for half a centry (e.g., double layers, Langmuir, 1929: pinch effect, Bennet, 1934). The conclusion is that astrophysics is too important to be left in the hands of the astrophysicist. Earth bound and space telescope data must be treated by scientists who are familiar with laboratory and magnetospheric physics and circuit theory, and of course with modern plasma theory. At least by volume the universe consists to more than 99 percent of plasma, and electromagnetic forces are 10/sup39/ time stronger than gravitation

  19. 77 FR 4370 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2012-01-27

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... meeting includes the following topics: --Astrophysics Division Update --Update on Balloons Return...

  20. 76 FR 35481 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2011-06-17

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... meeting includes the following topics: --Astrophysics Division Update. --Research and Analysis...

  1. 75 FR 2893 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-01-19

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... and Space Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA... the room. The agenda for the meeting includes the following topics: --Astrophysics Division...

  2. 75 FR 13597 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-03-22

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... and Space Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA... following topics: --Astrophysics Division Update. --Kepler Data Release Policy. It is imperative that...

  3. 77 FR 62536 - Meeting of Astrophysics Subcommittee of the NASA Advisory Council Science Committee

    Science.gov (United States)

    2012-10-15

    ... SPACE ADMINISTRATION Meeting of Astrophysics Subcommittee of the NASA Advisory Council Science Committee... Space Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory... topics: --Astrophysics Division Update --Proposed Data Centers Study --Strategic Implementation for...

  4. 75 FR 51116 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-08-18

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... the meeting includes the following topics: --Astrophysics Division Update --2010 Astronomy...

  5. 75 FR 74089 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-11-30

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... meeting includes the following topics: --Astrophysics Division Update --James Webb Space Telescope...

  6. 75 FR 33837 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2010-06-15

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... and Space Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA... of the room. The agenda for the meeting includes the following topics: --Astrophysics Division...

  7. 76 FR 5405 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2011-01-31

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... meeting includes the following topics: --Astrophysics Division Update --Update from the James Webb...

  8. 78 FR 66384 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2013-11-05

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... INFORMATION: The agenda for the meeting includes the following topics: --Astrophysics Division...

  9. 77 FR 38090 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2012-06-26

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee (APS) of the NASA Advisory Council... the following topics: --Astrophysics Division Update --James Webb Space Telescope Update...

  10. 76 FR 14106 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2011-03-15

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC... meeting includes the following topic: --Astrophysics Division Update. It is imperative that the meeting...

  11. Higher Education Resources from the NASA SMD Astrophysics Forum

    Science.gov (United States)

    Meinke, Bonnie K.; Schultz, Gregory R.; Manning, James; Smith, Denise A.; Bianchi, Luciana; Blair, William P.; Fraknoi, Andrew

    2014-06-01

    The NASA Astrophysics Science Education and Public Outreach Forum (SEPOF) coordinates the work of individual NASA Science Mission Directorate (SMD) Astrophysics EPO projects and their teams into a coherent, effective, efficient, and sustainable effort. The Astrophysics Forum assists scientists and educators with becoming involved in SMD E/PO and makes SMD E/PO resources and expertise accessible to the science and education communities. Here we describe how the Astrophysics Forum and the Astrophysics E/PO community have focused efforts to support and engage the higher education community on enhancing awareness of the resources available to them. To ensure Astrophysics higher education efforts are grounded in audience needs, we held informal conversations with instructors of introductory astronomy courses, convened sessions with higher education faculty and E/PO professionals at conferences, and examined existing literature and findings of the SMD Higher Education Working Group. To address the expressed needs, the Astrophysics Forum collaborated with the Astrophysics E/PO community, researchers, and Astronomy 101 instructors to place individual science discoveries and learning resources into context for higher education audiences. Among these resources are two Resource Guides on the topics of cosmology and exoplanets. These fields are ripe with scientific developments that college instructors have told us they find challenging to stay current. Each guide includes a wide variety of sources and is available through the ASP website: http://www.astrosociety.org/education/astronomy-resource-guides/ To complement the resource guides, we are developing a series of slide sets to help Astronomy 101 instructors incorporate new discoveries from individual SMD Astrophysics missions in their classrooms. The “Astro 101 slide sets” are 5-7 slide presentations on a new development or discovery from a NASA SMD Astrophysics mission relevant to an Astronomy 101 topic. We intend for

  12. Corruption of radio metric Doppler due to solar plasma dynamics: S/X dual-frequency Doppler calibration for these effects

    Science.gov (United States)

    Winn, F. B.; Reinbold, S. R.; Yip, K. W.; Koch, R. E.; Lubeley, A.

    1975-01-01

    Doppler data from Mariner 6, 7, 9, and 10 and Pioneer 10 and 11 were discussed and the rms noise level for various sun-earth-probe angles were shown. The noise levels of both S- and X-band Doppler data for sun-earth-probe angles smaller than 20 deg were observed to be orders of magnitude greater than nominal. Such solar plasma-related Doppler degradation reduced the Mariner 10-Mercury 11 encounter navigation accuracy by nearly a factor of 10. Furthermore, this degradation was shown to be indirectly related to plasma dynamics and not a direct measure of the dynamics.

  13. TeV Particle Astrophysics 2010, Booklet of abstracts

    International Nuclear Information System (INIS)

    The aim of the conference is to bring together theorists and experimentalists working in the fields of Particle Physics, Astrophysics and Cosmology, with a shared interest in physical processes at the TeV energy scale. After decades of theoretical speculation, the exploration of the TeV energy frontier has now in fact begun, with the results provided by ground-based and space-born observatories of gamma-rays (Fermi, HESS, Magic, Veritas, Cangaroo, Milagro), anti-matter (PAMELA, ATIC, HESS and soon AMS-02) and neutrinos (IceCube, Antares), with a large number of ongoing direct Dark Matter search experiments exploiting different detection techniques, and with the TeV particle accelerators Tevatron and the Large Hadron Collider. The physics underlying these experiments involves many intertwined issues, such as the nature of Dark Matter, Physics beyond the Standard Model, the origin of Cosmic Rays and the distribution of Dark and visible matter in the Universe. This document gathers only the abstracts of the papers. (authors)

  14. Recoiling Black Holes: Electromagnetic Signatures, Candidates, and Astrophysical Implications

    Directory of Open Access Journals (Sweden)

    S. Komossa

    2012-01-01

    Full Text Available Supermassive black holes (SMBHs may not always reside right at the centers of their host galaxies. This is a prediction of numerical relativity simulations, which imply that the newly formed single SMBH, after binary coalescence in a galaxy merger, can receive kick velocities up to several 1000 km/s due to anisotropic emission of gravitational waves. Long-lived oscillations of the SMBHs in galaxy cores, and in rare cases even SMBH ejections from their host galaxies, are the consequence. Observationally, accreting recoiling SMBHs would appear as quasars spatially and/or kinematically offset from their host galaxies. The presence of the “kicks” has a wide range of astrophysical implications which only now are beginning to be explored, including consequences for black hole and galaxy assembly at the epoch of structure formation, black hole feeding, and unified models of active galactic nuclei (AGN. Here, we review the observational signatures of recoiling SMBHs and the properties of the first candidates which have emerged, including follow-up studies of the candidate recoiling SMBH of SDSSJ092712.65+294344.0.

  15. PREFACE: NUBA Conference Series 1: Nuclear Physics and Astrophysics

    Science.gov (United States)

    Boztosun, I.; Balantekin, A. B.; Kucuk, Y.

    2015-04-01

    The international conference series ''NUBA Conference Series 1: Nuclear Physics and Astrophysics'' was held on September 14-21 2014 in Antalya-Turkey. Akdeniz University hosted the conference and the Adrasan Training and Application Centre was chosen as a suitable venue to bring together scientists from all over the world as well as from different parts of Turkey. The conference was supported by the Scientific and Technological Research Council of Turkey (TÜBìTAK) and Akdeniz University Nuclear Sciences Application and Research Center (NUBA). Based on the highly positive remarks received from the participants both during and after the conference, we believe that the event has proven to be a fulfilling experience for all those who took part. The conference provided an opportunity for the participants to share their ideas and experiences in addition to exploring possibilities for future collaborations. Participants of the conference focused on: • Nuclear Structure and Interactions • Nuclear Reactions, • Photonuclear Reactions and Spectroscopy • Nuclear and Particle Astrophysics • Nuclear Processes in Early Universe • Nuclear Applications • New Facilities and Instrumentation Participants included a number of distinguished invited speakers. There was significant interest from the international nuclear physics community and numerous abstracts and papers were submitted. The scientific committee conducted a careful and rigorous selection process, as a result of which 75 contributions were accepted. Of those, 65 of them were given as oral and 10 as poster presentations. The superb quality of the papers ensured fruitful discussion sessions. We thank all the participants for their efforts and also for promptly sending in their papers for publication. This issue of the Journal of Physics: Conference Series was peer-reviewed by expert referees and we also thank them for peer-reviewing the papers. The national and international advisory committee also deserve

  16. Boson-fermion stars exploring different configurations

    CERN Document Server

    Henriques, A B; Henriques, Alfredo B.; Mendes, Luis E.

    2003-01-01

    We use the flexibility of the concept of a fermion-boson star to explore different configurations, ranging from objects of atomic size and masses of the order $10^{18}$ g, up to objects of galactic masses and gigantic halos around a smaller core, with possible interesting applications to astrophysics and cosmology, particularly in the context of dark matter.

  17. Space explorers outreach program

    Science.gov (United States)

    Harper, D. A.

    1995-06-01

    For over three and a half years the Center for Astrophysical Research in Antarctica (CARA) has operated a program for African-American K-12 students in Chicago. Space Explorers (the high school students in the program participate in a wide range of educational activities in astronomy). They attend workshops at the Adler Planetarium, on the University of Chicago campus, and at Yerkes Observatory. CARA operates a summer institute for them every summer at Yerkes Observatory. A key program during the school year is one that uses the Adler Planetarium's Starlab. A Starlab is an inflatable, portable planetarium that can easily be transported to schools. The Space Explorers are highly experienced in the use of a Starlab and are trained to deliver programs for younger students. They reach over two thousand grammar school students each spring.

  18. The Trojan Horse Method: an Indirect Technique in Nuclear Astrophysics

    CERN Document Server

    Mukhamedzhanov, A M; Tribble, R E

    2006-01-01

    The Trojan Horse (TH) method is a powerful indirect technique that provides information to determine astrophysical factors for rearrangement processes at astrophysically relevant energies. A short coming for understanding the reliability of the technique has been determining the importance of nuclear and Coulomb effects on the energy dependence of the yield. Using a simple model, we demonstrate that off-energy-shell and Coulomb effects in the entry channel and the final state nuclear interactions do not change the energy dependence of the astrophysical factor extracted from the TH reaction. Some examples are presented.

  19. Astronomy education and the Astrophysics Source Code Library

    Science.gov (United States)

    Allen, Alice; Nemiroff, Robert J.

    2016-01-01

    The Astrophysics Source Code Library (ASCL) is an online registry of source codes used in refereed astrophysics research. It currently lists nearly 1,200 codes and covers all aspects of computational astrophysics. How can this resource be of use to educators and to the graduate students they mentor? The ASCL serves as a discovery tool for codes that can be used for one's own research. Graduate students can also investigate existing codes to see how common astronomical problems are approached numerically in practice, and use these codes as benchmarks for their own solutions to these problems. Further, they can deepen their knowledge of software practices and techniques through examination of others' codes.

  20. Recent Developments in Astrophysical and Cosmological Exploitation of Microwave Surveys

    DEFF Research Database (Denmark)

    Burigana, Carlo; Davies, Rodney D.; De Bernardis, Paolo;

    2013-01-01

    In this paper, we focus on the astrophysical results and the related cosmological implications derived from recent microwave surveys, with emphasis to those coming from the Planck mission. We critically discuss the impact of systematic effects and the role of methods to separate the cosmic...... microwave background (CMB) signal from the astrophysical emissions and each different astrophysical component from the others. We then review the state-of-the-art diffuse emissions, extragalactic sources, cosmic infrared background and galaxy clusters, addressing the information they provide to our global...

  1. Shape: A 3D Modeling Tool for Astrophysics.

    Science.gov (United States)

    Steffen, Wolfgang; Koning, Nicholas; Wenger, Stephan; Morisset, Christophe; Magnor, Marcus

    2011-04-01

    We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type, and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.

  2. Recent Nuclear Astrophysics Data Activities in the US

    Energy Technology Data Exchange (ETDEWEB)

    Bardayan, D.W.; Blackmon, J.C.; Browne, E.; Firestone, R.B.; Hale, G.M.; Hoffman, R.D.; Ma, Z.; McLane, V.; Norman, E.B.; Shu, N.; Smith, D.L.; Smith, M.S.; Van Wormer, L.A.; Woosley, S.E.; Wu, S.-C.

    1999-08-30

    Measurements in nuclear physics laboratories form the empirical foundation for new, realistic, sophisticated theoretical models of a wide variety of astrophysical systems. The predictive power of these models has, in many instances, a strong dependence on the input nuclear data, and more extensive and accurate nuclear data is required for these models than ever before. Progress in astrophysics can be aided by providing scientists with more usable, accurate, and significant amounts of nuclear data in a timely fashion in formats that can be easily incorporated into their models. A number of recent data compilations, evaluations, calculations, and disseminations that address nuclear astrophysics data needs will be described.

  3. Astrophysical phenomena related to supermassive black holes

    Science.gov (United States)

    Pott, Jörg-Uwe

    2006-12-01

    astrophysical context of the observation. The observational techniques chosen vary in dependence of the observed phenomenon. One major goal of especially Chapters 3 and 4 is to prove by successful explorative observations the scientific perspectives of the new instruments. Chapter 3 deals with the pioneering interferometric infrared study of stellar sources and their surroundings in the immediate vicinity of the SMBH at the center of the Milky Way. I was able to use the resolving power of an optical large baseline interferometer (OLBI) to investigate for the first time the different structures and excitation conditions of interstellar and circumstellar dust in 200 mpc distance to the SMBH. It is unknown whether the standard models for star and dust formation, which themselves dominate the infrared appearance of an inactive galaxy as the Milky Way, still apply under the strong tidal forces of gravity, exerted by the central SMBH. During the course of my doctoral research, I worked 2.5 years within the VLT Interferometry (VLTI) group of the European Southern Observatory (ESO) in M"unchen and Chile. I obtained the very first infrared fringes on GC sources and investigated the different instrument capabilities at the current sensitivity limit of the VLTI. The VLTI is the world leading stellar interferometric facility providing the infrastructure to combine the light of up to four 8m-class Adaptive Optics corrected telescopes, which themselves represent the state-of-the-art of optical-infrared telescope technology. The accomplished work includes the investigation of different data reduction techniques with respect to maximum accuracy and signal-to-noise ratios. The VLTI is right in the process of construction. While first modes are already open to the astronomical community, several advanced modes and instruments are still at different preliminary stages, ranging from early design studies to advanced instrument commissioning. The experiences of my VLTI observations, fully exploiting

  4. Astrophysical Effects of Scalar Dark Matter Miniclusters

    CERN Document Server

    Zurek, K M; Quinn, T R; Zurek, Kathryn M.; Hogan, Craig J.; Quinn, Thomas R.

    2006-01-01

    We model the formation, evolution and astrophysical effects of dark compact Scalar Miniclusters (``ScaMs''). These objects arise when a scalar field, with an axion-like or Higgs-like potential, undergoes a second order phase transition below the QCD scale. Such a scalar field may couple too weakly to the standard model to be detectable directly through particle interactions, but may still be detectable by gravitational effects, such as lensing and baryon accretion by large, gravitationally bound miniclusters. The masses of these objects are shown to be constrained by the Ly$\\alpha$ power spectrum to be less than $\\sim 10^4 M_\\odot$, but they may be as light as classical axion miniclusters, of the order of $10^{-12} M_\\odot$. We simulate the formation and nonlinear gravitational collapse of these objects around matter-radiation equality using an N-body code, estimate their gravitational lensing properties, and assess the feasibility of studying them using current and future lensing experiments. Future MACHO-ty...

  5. Welcome to the Universe an astrophysical tour

    CERN Document Server

    DeGrasse Tyson, Neil; Gott, Richard J

    2016-01-01

    Welcome to the Universe is a personal guided tour of the cosmos by three of today's leading astrophysicists. Inspired by the enormously popular introductory astronomy course that Neil deGrasse Tyson, Michael A. Strauss, and J. Richard Gott taught together at Princeton, this book covers it all--from planets, stars, and galaxies to black holes, wormholes, and time travel. Describing the latest discoveries in astrophysics, the informative and entertaining narrative propels you from our home solar system to the outermost frontiers of space. How do stars live and die? Why did Pluto lose its planetary status? What are the prospects of intelligent life elsewhere in the universe? How did the universe begin? Why is it expanding and why is its expansion accelerating? Is our universe alone or part of an infinite multiverse? Answering these and many other questions, the authors open your eyes to the wonders of the cosmos, sharing their knowledge of how the universe works. Breathtaking in scope and stunningly illustrate...

  6. A quarter century of astrophysics with Japan

    CERN Document Server

    Yock, Philip

    2015-01-01

    On February 23 1987 a supernova (exploding star) was observed in the Large Cloud of Magellan, the brightest supernova in 400 years. It spurred the commencement of collaborative research in astrophysics between Japan and New Zealand that is still ongoing after 25 years. The initial aim of the two countries was to search for evidence of cosmic rays being emitted by the supernova in a project named JANZOS. A large cosmic ray detector was installed near the summit of the Black Birch range in Marlborough to monitor the supernova but, after seven years of operations, the results proved to be negative. In 1994 a second phase of research was commenced, this time at the Mt John University Observatory in Canterbury under the emblem MOA. The aim of the MOA project is to study dark matter and extrasolar planets using a novel gravitational microlensing technique. A 1.8m telescope was built at the observatory, and several planets were subsequently found. Some have exotic properties, the most exotic being a new class of fre...

  7. AstroDance: Teaching Astrophysics Through Dance?

    Science.gov (United States)

    Noel-Storr, Jacob; Campanelli, M.; Bochner, J.; Warfield, T.; Bischof, H.; Zlochower, Y.; Nordhaus, J.; Watkins, G.; NSF CRPA AstroDance Team

    2014-01-01

    Through a collaboration involving scientists, artists and educators, members of the Center for Computational Relativity and Gravitation and the National Technical Institute for the Deaf at the Rochester Institute of Technology we developed a unique project for Communicating Research to Public Audiences. The project used dance and multi-media theater techniques to expose a broad audience, about half of which is comprised of deaf and hard-of-hearing individuals, to an aesthetic, educational performance representing the concepts of gravitational physics in astrophysical settings. Since deaf and hard-of-hearing people rely heavily on visual communication for learning and gaining access to information, dance and multi-media theater provide a kinesthetic and visual experience that is fully accessible to them, as well as hearing audience members, and help facilitate their learning and development of non-linguistic representations of concepts. Here we present the results of our research into the learning outcomes for the diverse audiences of this project in terms of both knowledge and attitudes towards science.

  8. Astrophysical Constraints on Singlet Scalars at LHC

    CERN Document Server

    Hertzberg, Mark P

    2016-01-01

    We consider the viability of new heavy gauge singlet scalar particles at the LHC. Our motivation for this study comes from the possibility of a new particle with mass ~ 750 GeV decaying significantly into two photons at LHC, but our analysis applies more broadly. We show that there are significant constraints from astrophysics and cosmology on the simplest UV complete models that incorporate such a particle and its associated collider signal. The simplest and most obvious UV complete model that incorporates the signal is that it arises from a new singlet scalar (or pseudo-scalar) coupled to a new electrically charged and colored heavy fermion. Here we show that these new fermions (and anti-fermions) would be produced in the early universe, then form new color singlet heavy mesons with light quarks, obtain a non-negligible freeze-out abundance, and remain in kinetic equilibrium until decoupling. These heavy mesons possess interesting phenomenology, dependent on their charge, including forming new bound states ...

  9. Two instruments for far-infrared astrophysics

    International Nuclear Information System (INIS)

    Two instruments for far-infrared astrophysics are described. The first is a broad-band photometer used on White Mountain for astronomical observations from 10 to 30 cm-1 (300 GHz to 1 THz; lambda, 1 mm to 330 μ). The optical system of the telescope includes a light-weight, high-speed, chopping secondary. The L 4He-cooled photometer uses low-pass filters and a L3He-cooled, composite bolometer. The system performance is evaluated, and the site is compared to other possible platforms. The second project is a balloon-borne spectroradiometer to measure the cosmic background radiation from 3 to 10 cm-1 (100 GHz to 300 GHz; lambda, 3 mm to 1 mm). The apparatus has five band-pass filters with excellent rejection at higher frequencies, a low-noise chopper, and an internal calibrator. We describe the design and use of calibrators for such an experiment and develop a model of calibration procedures. The calibrations of several reported measurements are analyzed with this model, and flaws are found in one procedure. Finally, the system performance is used to estimate the accuracy this experiment can achieve

  10. Atomic Chemistry in Turbulent Astrophysical Media

    Science.gov (United States)

    Scannapieco, Evan; Gray, William; Kasen, Daniel

    2015-08-01

    I will describe direct numerical simulations of turbulent astrophysical media that explicitly track the non-equillibrium evolution of atomic hydrogen, helium, carbon, nitrogen, oxygen, neon, sodium, magnesium, silicon, and iron. The simulations include collisional ionization, recombination, charge-exchange reactions, photonionization, photoheating, and species-by-species radiative cooling. For a given background shape, the medium reaches a global steady state that is purely a function of three numbers: (i) the ionization parameter, (ii) the one-dimensional turbulent velocity dispersion (sigma1D) and (iii) the product of the mean density and the turbulent driving scale. Our simulations span a large range of conditions, and we describe their application to ongoing studies of the interstellar medium in starbursting galaxies and the circumgalactic medium as probed by quasar absorption line studies. Our results are available as a series of oneline tables, that allow for future studies to account for nonequilibrium effects in turbulent media with sigma1D = 5-60 km/s, regardless of physical scale.

  11. Cosmology, astrophysics and elementary particle physics

    International Nuclear Information System (INIS)

    In most of this review it is assumed that the laws of physics are unchanging in space and time and it is discussed how modern developments in elementary particle physics influence one's understanding of the Universe and conversely the possibility that astronomical observations may give information about elementary particle physics. In particular the physics of the early Universe is studied and the role of new particles such as heavy leptons, neutrinos and quarks and the possible relationship of the net baryon number of the Universe to unified models of elementary particle physics is discussed. The role of neutrinos in stellar evolution, particularly in the explosion of supernovae and in the cooling of neutron stars is considered, black holes are discussed, especially in connection with Hawking's discovery that low-mass black holes can emit a thermal distribution of particles which could be of cosmological or astrophysical importance. Finally the evidence that the laws of physics are, in fact, unchanging is discussed and it is concluded that there is no clear case in favour of change. 346 references. (author)

  12. Some Aspects of Strange Matter in Astrophysics

    CERN Document Server

    Banerjee, Shibaji

    2014-01-01

    The present work is connected with the investigation of the origin and properties of compact astrophysical objects endowed with strangeness, with the objective of finding out their relevance in the formation and evolution of the universe. In the first part of the thesis, Chap.~1-3, we discuss a model, proposed by us, to describe the propagation of small lumps of Strange Quark Matter (SQM) or strangelets, through the Terrestrial atmosphere. The theoretical results were found to be well correlated with exotic cosmic ray events characterized by very low charge to mass ratio. In the next part, we have investigated the other end of the mass spectrum of SQM. In Chap 5, we have developed an analytical expression for the Chandrasekhar Limit of Strange Quark Stars. The limit is found to depend on the fundamental constants (including the bag constant). In the last chapter we have endeavored to show that the quark nuggets, surviving the quark-hadron phase transition in the millisecond era of the early Universe can provi...

  13. MPI-AMRVAC FOR SOLAR AND ASTROPHYSICS

    International Nuclear Information System (INIS)

    In this paper, we present an update to the open source MPI-AMRVAC simulation toolkit where we focus on solar and non-relativistic astrophysical magnetofluid dynamics. We highlight recent developments in terms of physics modules, such as hydrodynamics with dust coupling and the conservative implementation of Hall magnetohydrodynamics. A simple conservative high-order finite difference scheme that works in combination with all available physics modules is introduced and demonstrated with the example of monotonicity-preserving fifth-order reconstruction. Strong stability-preserving high-order Runge-Kutta time steppers are used to obtain stable evolutions in multi-dimensional applications, realizing up to fourth-order accuracy in space and time. With the new distinction between active and passive grid cells, MPI-AMRVAC is ideally suited to simulate evolutions where parts of the solution are controlled analytically or have a tendency to progress into or out of a stationary state. Typical test problems and representative applications are discussed with an outlook toward follow-up research. Finally, we discuss the parallel scaling of the code and demonstrate excellent weak scaling up to 30, 000 processors, allowing us to exploit modern peta-scale infrastructure

  14. Astrophysics of Galactic charged cosmic rays

    CERN Document Server

    Castellina, Antonella

    2011-01-01

    A review is given of the main properties of the charged component of galactic cosmic rays, particles detected at Earth with an energy spanning from tens of MeV up to about 10^19 eV. After a short introduction to the topic and an historical overview, the properties of cosmic rays are discussed with respect to different energy ranges. The origin and the propagation of nuclei in the Galaxy are dealt with from a theoretical point of view. The mechanisms leading to the acceleration of nuclei by supernova remnants and to their subsequent diffusion through the inhomogeneities of the galactic magnetic field are discussed and some clue is given on the predictions and observations of fluxes of antimatter, both from astrophysical sources and from dark matter annihilation in the galactic halo. The experimental techniques and instrumentations employed for the detection of cosmic rays at Earth are described. Direct methods are viable up to 10^14 eV, by means of experiments flown on balloons or satellites, while above that ...

  15. Astrophysical constraints on millicharged atomic dark matter

    CERN Document Server

    Kvam, Audrey K

    2014-01-01

    Some models of inelastic dark matter posit the existence of bound states under some new $U(1)'$ gauge symmetry. If this new dark photon kinetically mixes with the standard model photon, then the constituent particles in these bound states can acquire a fractional electric charge. This electric charge renders a dark-matter medium dispersive. We compute this frequency-dependent index of refraction for such a medium and use the frequency-dependent arrival time of light from astrophysical sources to constrain the properties of dark atoms in the medium. Using optical-wavelength observations from the Crab Pulsar, we find the electric millicharge of dark (electrons) protons to be smaller than the electric charge $e$ for dark atom masses below 100 keV, assuming a dark fine structure constant $\\boldsymbol{\\alpha}=1$. We estimate that future broadband observations of gamma-ray bursts can produce constraints on the millicharge of dark atoms with masses in the keV range that are competitive with existing collider constra...

  16. Astrophysical and cosmological constraints on supersymmetric theories

    International Nuclear Information System (INIS)

    We summarize the astrophysical and cosmological constraints on theories in which a global supersymmetry remains unbroken down to an energy scale of the order of TeV. The emission of Goldstinos (and possibly photinos) from red giant stars constrain ν (the scale of supersymmetry breaking) to be greater than 0(50 GeV). If ν is 0(1 TeV), then it follows from big bang nucleo-synthesis that at least one of the following particles must be more massive than 0(10 MeV): νsub(tau), the photino, or the Goldstino. If ν is greater than 0(10 TeV), then the big bang nucleosynthesis constraints are much less restritive. The mass density contributed by relic photinos and the contribution of photons from their decays to various diffuse photon backgrounds restrict the photino mass to be either greater than 0(10 MeV) or less than 0(200 eV)

  17. Walter Baade : a life in astrophysics

    Science.gov (United States)

    Osterbrock, Donald E.

    Although less well known outside the field than Edwin Hubble, Walter Baade (1893-1960) was arguably the most influential observational astronomer of the twentieth century. Written by a fellow astronomer deeply familiar with Baade and his work, this is the first biography of this major figure in American astronomy. In it, Donald Osterbrock suggests that Baade's greatest contribution to astrophysics was not, as is often contended, his revision of Hubble's distance and age scales for the universe. Rather, it was his discovery of two distinct stellar populations: old and young stars. This discovery opened wide the previously marginal fields of stellar and galactic evolution. Baade was born, educated, and gained his early research experience in Germany. He came to the United States in 1931 as a staff member of Mount Wilson Observatory, which housed the world's largest telescope. There, he pioneered research on supernovae. With the 100-inch telescope, he studied globular clusters and the structure of the Milky Way, every step leading him closer to the population concept he discovered during the wartime years, when the skies of southern California were briefly darkened. After his great discovery, Baade continued his research with the new 200-inch telescope at Palomar. Always respected and well liked, he became even more famous among astronomers as they shifted their research to the fields he had opened. Publicity-shy and seemingly unconcerned with publication, however, Baade's celebrity remained largely within the field.

  18. Recent Laboratory Astrophysics Experiments at LULI

    Science.gov (United States)

    Koenig, Michel; Michaut, Claire; Loupias, Bérénice; Falize, Emeric; Gregory, Chris; Kuramitsu, Yasuhiro; Dono, Seiichi; Vinci, Tommaso; Waugh, Jonny; Woolsey, Nigel; Ozaki, Norimasa; Benuzzi-Mounaix, Alessandra; Ravasio, Alessandra; Bouquet, Serge; Goahec, Marc Rabec Le; Nazarov, Wigen; Pikuz, Serguey; Sakawa, Youichi; Takabe, Hideaki; Kodama, Ryosuke

    At the LULI laboratory we developed since a few years a program on several topics related to laboratory astrophysics: high velocity jets, shock waves in density gradients, collisionless shocks, and radiative shocks (RS). In this paper, the latest experiments related to RS’s obtained on the new LULI2000 facility and on GEKKOXII are presented. In particular a strong radiative precursor was observed and its time evolution compared with 2D radiative simulations. The second topic developed at LULI is related to plasma jets which are often observed in Young Stellar Objects (YSO), during their phase of bulk contraction. They interact with the interstellar medium resulting in emission lobes, including the so-called bow shocks. The objective of our experiments was to generate plasma jets propagating through an ambient medium. To this aim, we developed a new target design (a foam filled cone ended with a “nozzle”) in order to generate a plasma jet. A jet-like structure was observed and its time evolution studied by varying the foam density. Interaction with ambient medium was recently performed showing growing instabilities for low density gas.

  19. High-Energy Spectroscopic Astrophysics Swiss Society for Astrophysics and Astronomy

    CERN Document Server

    Kahn, Steven M; von Ballmoos, Peter

    2005-01-01

    After three decades of intense research in X-ray and gamma-ray astronomy, the time was ripe to summarize basic knowledge on X-ray and gamma-ray spectroscopy for interested students and researchers ready to become involved in new high-energy missions. This volume exposes both the scientific basics and modern methods of high-energy spectroscopic astrophysics. The emphasis is on physical principles and observing methods rather than a discussion of particular classes of high-energy objects, but many examples and new results are included in the three chapters as well.

  20. Investigations in γ-Ray Astrophysics and Astroparticle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Krennrich, Frank [Iowa State Univ., Ames, IA (United States). Dept. of Physics and Astronomy

    2016-06-28

    This report describes the status of data analysis efforts, results and publications of research grant DE-SC0009917. The research is focused on TeV gamma-ray studies of astrophysical sources and related particle physics questions.

  1. Structure of proton-rich nuclei of astrophysical interest

    Energy Technology Data Exchange (ETDEWEB)

    Roeckl, E. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)

    1998-06-01

    Recent experimental data concerning proton-rich nuclei between A=20 and A=100 are presented and discussed with respect to their relevance to the astrophysical rp process and to the calibration of solar neutrino detectors. (orig.)

  2. Global transmission coefficients in Hauser-Feshbach calculations for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Rauscher, T. [Inst. fuer Physik, Univ. Basel, Basel (Switzerland)

    1998-06-01

    The current status of optical potentials employed in the prediction of thermonuclear reaction rates for astrophysics in the Hauser-Feshbach formalism is discussed. Special emphasis is put on {alpha}+nucleus potentials. Further experimental efforts are motivated. (orig.)

  3. Dynamic of astrophysical jets in the complex octonion space

    CERN Document Server

    Weng, Zi-Hua

    2015-01-01

    The paper aims to consider the strength gradient force as the dynamic of astrophysical jets, explaining the movement phenomena of astrophysical jets. J. C. Maxwell applied the quaternion analysis to describe the electromagnetic theory. This encourages others to adopt the complex quaternion and octonion to depict the electromagnetic and gravitational theories. In the complex octonion space, it is capable of deducing the field potential, field strength, field source, angular momentum, torque, force and so forth. As one component of the force, the strength gradient force relates to the gradient of the norm of field strength only, and is independent of not only the direction of field strength but also the mass and electric charge for the test particle. When the strength gradient force is considered as the thrust of the astrophysical jets, one can deduce some movement features of astrophysical jets, including the bipolarity, matter ingredient, precession, symmetric distribution, emitting, collimation, stability, c...

  4. ACCESS: Enabling an Improved Flux Scale for Astrophysics

    CERN Document Server

    Kaiser, Mary Elizabeth; McCandliss, Stephan R; Sahnow, David J; Barkhouser, Robert H; Van Dixon, W; Feldman, Paul D; Moos, H Warren; Orndorff, Joseph; Pelton, Russell; Riess, Adam G; Rauscher, Bernard J; Kimble, Randy A; Benford, Dominic J; Gardner, Jonathan P; Hill, Robert J; Woodgate, Bruce E; Bohlin, Ralph C; Deustua, Susana E; Kurucz, Robert; Lampton, Michael; Perlmutter, Saul; Wright, Edward L

    2010-01-01

    Improvements in the precision of the astrophysical flux scale are needed to answer fundamental scientific questions ranging from cosmology to stellar physics. The unexpected discovery that the expansion of the universe is accelerating was based upon the measurement of astrophysical standard candles that appeared fainter than expected. To characterize the underlying physical mechanism of the "Dark Energy" responsible for this phenomenon requires an improvement in the visible-NIR flux calibration of astrophysical sources to 1% precision. These improvements will also enable large surveys of white dwarf stars, e.g. GAIA, to advance stellar astrophysics by testing and providing constraints for the mass-radius relationship of these stars. ACCESS (Absolute Color Calibration Experiment for Standard Stars) is a rocket-borne payload that will enable the transfer of absolute laboratory detector standards from NIST to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of R = 5...

  5. Astronomy and Astrophysics in the Philosophy of Science

    CERN Document Server

    Anderl, Sibylle

    2015-01-01

    This article looks at philosophical aspects and questions that modern astrophysical research gives rise to. Other than cosmology, astrophysics particularly deals with understanding phenomena and processes operating at "intermediate" cosmic scales, which has rarely aroused philosophical interest so far. Being confronted with the attribution of antirealism by Ian Hacking because of its observational nature, astrophysics is equipped with a characteristic methodology that can cope with the missing possibility of direct interaction with most objects of research. In its attempt to understand the causal history of singular phenomena it resembles the historical sciences, while the search for general causal relations with respect to classes of processes or objects can rely on the "cosmic laboratory": the multitude of different phenomena and environments, naturally provided by the universe. Furthermore, the epistemology of astrophysics is strongly based on the use of models and simulations and a complex treatment of la...

  6. Creative Writing and Learning in a Conceptual Astrophysics Course

    Science.gov (United States)

    Berenson, R.

    2012-08-01

    Creative writing assignments in a conceptual astrophysics course for liberal arts students can reduce student anxiety. This study demonstrates that such assignments also can aid learning as demonstrated by significantly improved performance on exams.

  7. Stars in the teaching of astrophysics at grammar schools.

    Science.gov (United States)

    Štefl, V.

    The paper subjects to theoretical analysis the topic "Stars" of the teaching programme of astrophysics at grammar schools. Diagrams express the relations among parameters of stars, sources of energy, structure and evolution of stars.

  8. Astrophysics is easy! an introduction for the amateur astronomer

    CERN Document Server

    Inglis, Mike

    2007-01-01

    With some justification, many amateur astronomers believe astrophysics is a very difficult subject, requiring at least degree-level mathematics to understand it properly. This isn’t necessarily the case. Mike Inglis' quantitative approach to the subject explains all aspects of astrophysics in simple terms and cuts through the incomprehensible mathematics with which this fascinating subject is all too often associated. Astrophysics is Easy! begins by looking at the H-R diagram and other basic tools of astrophysics, then ranges across the universe, from a first look at the interstellar medium and nebulae, through the birth, evolution and death of stars, to the physics of galaxies and clusters of galaxies. A unique feature of this book is the way that Dr. Inglis lists example objects for practical observation at every stage, so that practical astronomers can go and look at the object or objects under discussion – using only easily-available commercial amateur equipment.

  9. NASA Astrophysics EPO Community: Enhancing STEM Experience of Undergraduates

    Science.gov (United States)

    Manning, J.; Meinke, B. K.; Lawton, B.; Smith, D. A.; Bartolone, L.; Schultz, G.; NASA Astrophysics EPO Community

    2015-11-01

    The NASA Science Mission Directorate (SMD) Astrophysics Education and Public Outreach (EPO) community and Forum work together to capitalize on the cutting-edge discoveries of NASA Astrophysics missions to enhance the Science, Technology, Engineering, and Math (STEM) experience of undergraduates. The NASA SMD Astrophysics EPO community has proven expertise in providing both professional development and resources to faculty at two- and four-year institutions and in offering internships and student collaboration opportunities. These mission- and grant-based EPO programs are uniquely poised to foster collaboration between scientists with content expertise and educators with pedagogy expertise. We present examples of how the NASA Astrophysics EPO community and Forum engage the higher education community in these ways, including associated metrics and evaluation findings.

  10. High-Altitude Ballooning Program at the Indian Institute of Astrophysics

    CERN Document Server

    Nayak, A; Safonova, M; Murthy, Jayant

    2013-01-01

    We have begun a program of high altitude ballooning at the Indian Institute of Astrophysics, Bangalore. Recent advances in balloons as well as in electronics have made possible scientific payloads at costs accessible to university departments. The primary purpose of this activity is to test low-cost ultraviolet (UV) payloads for eventual space flight, but to also explore phenomena occurring in the upper atmosphere, including sprites and meteorite impacts, using balloon-borne payloads. This paper discusses the results of three tethered balloon experiments carried out at the CREST campus of IIA, Hosakote and our plans for the future. We also describe the stages of payload development for these experiments.

  11. Creating White Dwarf Photospheres in the Laboratory: Strategy for Astrophysics Applications

    CERN Document Server

    Falcon, Ross E; Bailey, J E; Ellis, J L; Carlson, A L; Gomez, T A; Montgomery, M H; Winget, D E; Chen, E Y; Gomez, M R; Nash, T J; Pille, T M

    2012-01-01

    Astrophysics experiments by Falcon et al. to create white dwarf photospheres in the laboratory are currently underway. The experimental platform measures Balmer line profiles of a radiation-driven, pure hydrogen plasma in emission and in absorption for conditions at T_e ~ 1 eV, n_e ~ 10^17 cm^-3. These will be used to compare and test line broadening theories used in white dwarf atmosphere models. The flexibility of the platform allows us to expand the direction of our experiments using other compositions. We discuss future prospects such as exploring helium plasmas and carbon/oxygen plasmas relevant to the photospheres of DBs and hot DQs, respectively.

  12. Astrophysical aspects of neutrino dynamics in ultra-degenerate quark gluon plasma

    CERN Document Server

    Adhya, Souvik Priyam

    2016-01-01

    The cardinal focus of the present review is to explore the role of neutrinos originating from the ultra-dense core of neutron stars composed of quark gluon plasma in the astrophysical scenario. The collective excitations of the quarks involving the neutrinos through the different kinematical processes have been studied. The cooling of the neutron stars as well as pulsar kicks due to asymmetric neutrino emission have been discussed in detail. Results involving calculation of relevant physical quantities like neutrino mean free path and emissivity have been presented in the framework of non-Fermi liquid behavior as applicable to ultra-degenerate plasma.

  13. Technology Development for a Neutrino AstrophysicalObservatory

    Energy Technology Data Exchange (ETDEWEB)

    Chaloupka, V.; Cole, T.; Crawford, H.J.; He, Y.D.; Jackson, S.; Kleinfelder, S.; Lai, K.W.; Learned, J.; Ling, J.; Liu, D.; Lowder, D.; Moorhead, M.; Morookian, J.M.; Nygren, D.R.; Price, P.B.; Richards, A.; Shapiro, G.; Shen, B.; Smoot, George F.; Stokstad, R.G.; VanDalen, G.; Wilkes, J.; Wright, F.; Young, K.

    1996-02-01

    We propose a set of technology developments relevant to the design of an optimized Cerenkov detector for the study of neutrino interactions of astrophysical interest. Emphasis is placed on signal processing innovations that enhance significantly the quality of primary data. These technical advances, combined with field experience from a follow-on test deployment, are intended to provide a basis for the engineering design for a kilometer-scale Neutrino Astrophysical Observatory.

  14. Technology development for a neutrino astrophysical observatory. Letter of intent

    Energy Technology Data Exchange (ETDEWEB)

    Chaloupka, V.; Cole, T.; Crawford, H.J. [and others

    1996-02-01

    The authors propose a set of technology developments relevant to the design of an optimized Cerenkov detector for the study of neutrino interactions of astrophysical interest. Emphasis is placed on signal processing innovations that enhance significantly the quality of primary data. These technical advances, combined with field experience from a follow-on test deployment, are intended to provide a basis for the engineering design for a kilometer-scale Neutrino Astrophysical Observatory.

  15. Computational Astrophysics Towards Exascale Computing and Big Data

    Science.gov (United States)

    Astsatryan, H. V.; Knyazyan, A. V.; Mickaelian, A. M.

    2016-06-01

    Traditionally, Armenia has a leading position both within the computer science and Information Technology and Astronomy and Astrophysics sectors in the South Caucasus region and beyond. For instance recent years Information Technology (IT) became one of the fastest growing industries of the Armenian economy (EIF 2013). The main objective of this article is to highlight the key activities that will spur Armenia to strengthen its computational astrophysics capacity thanks to the analysis made of the current trends of e-Infrastructures worldwide.

  16. Technology development for a neutrino astrophysical observatory. Letter of intent

    International Nuclear Information System (INIS)

    The authors propose a set of technology developments relevant to the design of an optimized Cerenkov detector for the study of neutrino interactions of astrophysical interest. Emphasis is placed on signal processing innovations that enhance significantly the quality of primary data. These technical advances, combined with field experience from a follow-on test deployment, are intended to provide a basis for the engineering design for a kilometer-scale Neutrino Astrophysical Observatory

  17. The Trojan Horse Method: an Indirect Technique in Nuclear Astrophysics

    OpenAIRE

    Mukhamedzhanov, A. M.; Spitaleri, C.(Dip. di Fisica e Astronomia, Univ. di Catania, via S. Sofia, Catania, Italy); Tribble, R. E.

    2006-01-01

    The Trojan Horse (TH) method is a powerful indirect technique that provides information to determine astrophysical factors for rearrangement processes at astrophysically relevant energies. A short coming for understanding the reliability of the technique has been determining the importance of nuclear and Coulomb effects on the energy dependence of the yield. Using a simple model, we demonstrate that off-energy-shell and Coulomb effects in the entry channel and the final state nuclear interact...

  18. 78 FR 2293 - NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting

    Science.gov (United States)

    2013-01-10

    ... SPACE ADMINISTRATION NASA Advisory Council; Science Committee; Astrophysics Subcommittee; Meeting AGENCY... Administration (NASA) announces a meeting of the Astrophysics Subcommittee of the NASA Advisory Council (NAC...: --Astrophysics Division Update --NASA Astrophysics Roadmapping It is imperative that the meeting be held on...

  19. Dynamic of astrophysical jets in the complex octonion space

    Science.gov (United States)

    Weng, Zi-Hua

    2015-06-01

    The paper aims to consider the strength gradient force as the dynamic of astrophysical jets, explaining the movement phenomena of astrophysical jets. J. C. Maxwell applied the quaternion analysis to describe the electromagnetic theory. This encourages others to adopt the complex quaternion and octonion to depict the electromagnetic and gravitational theories. In the complex octonion space, it is capable of deducing the field potential, field strength, field source, angular momentum, torque, force and so forth. As one component of the force, the strength gradient force relates to the gradient of the norm of field strength only, and is independent of not only the direction of field strength but also the mass and electric charge for the test particle. When the strength gradient force is considered as the thrust of the astrophysical jets, one can deduce some movement features of astrophysical jets, including the bipolarity, matter ingredient, precession, symmetric distribution, emitting, collimation, stability, continuing acceleration and so forth. The above results reveal that the strength gradient force is able to be applied to explain the main mechanical features of astrophysical jets, and is the competitive candidate of the dynamic of astrophysical jets.

  20. NASA Astrophysics E/PO Impact: The Astrophysics Educator Ambassador Program

    Science.gov (United States)

    Cominsky, Lynn R.; McLin, Kevin M.; SSU E/PO Team

    2015-01-01

    The NASA Astrophysics Educator Ambassador (EA) Program began in 2001 as part of the GLAST (now Fermi) E/PO effort at Sonoma State University. The program currently supports 15 EAs, sponsored by either Fermi, Swift, XMM-Newton or NuSTAR. This group of master educators work with mission scientists and E/PO personnel to develop curricula and train teachers; they also do workshops for students and outreach events with the general public. We have held six bi-annual weeklong trainings at SSU: each has had a different focus. Special topics of study have included the Dark Universe, Particle Physics and Gravitation. Additionally, time is given for the EAs to share ideas from their own workshops. In the 14 years of the program, the total number of teachers attending EA-run workshops is over 65,000. Over 1500 workshops have been evaluated by participants, and these evaluation scores and comments have been further analyzed by external experts at WestEd. The WestEd report summarizes the results: "Almost universally high ratings are obtained even though a wide range of participants by grade level, teaching experience or interest typically attends EA conference sessions, and they can bring quite different needs or perspectives." In this talk, I will report details of the impacts of the Astrophysics EA program.

  1. Gravitational waves: A challenge to theoretical astrophysics

    International Nuclear Information System (INIS)

    During the 20th century, new windows on the Universe have been opened by the advent of radio astronomy and X-ray astronomy and these, together with the great advances in optical astronomy (both from the Earth's surface and from space), have revolutionized our understanding of the Universe and the way in which it works. Now, as we enter the twenty-first century, we await the opening of another new window - that provided by gravitational waves - which will allow us a closer 'view' of black holes and neutron stars, as well as providing a new probe of processes in the very early Universe. This is an exciting prospect but one which poses a serious challenge to theoretical astrophysics. The new generation of detectors (both laser interferometers and resonant detectors) require input from theoreticians regarding the possible mechanisms for generation of gravitational waves by astronomical sources and predictions of the waveforms produced. This input is essential in order both to tune the parameters of the detectors and to provide templates for use in extracting the tiny gravitational-wave signals from the ambient noise. Also, we need to understand how gravitational wave data, when it arrives, could be used in order to obtain information about the nature of the sources and about their dynamical evolution as well as, perhaps, giving deeper insights into some questions of fundamental physics by means of probing the state of matter under the extreme conditions of energy and pressure found in the interior of neutron stars and in the very early universe. This can provide opportunities beyond the capabilities of experiments carried out in terrestrial laboratories. For a week at the beginning of June 2000, 106 scientists from 28 countries came to Trieste for a meeting whose aim was to present a survey of the current status of the response of theoreticians to the challenge described above, as well as including progress reports on the different types of detector. The meeting was a

  2. Planck Scale Effects in Astrophysics and Cosmology

    International Nuclear Information System (INIS)

    It has been generally agreed that putting together the principles of quantum theory and general relativity will usher the next revolution in physics. The trouble, of course, is that we have been now waiting for several decades for this revolution to take place. While people get excited about different directions of development every once in a while (with some excitements propped up by a larger number of researchers than others), it is probably fair to say that nothing which can be called definitive progress has taken place in the last several decades. Given the state of affairs it is definitely worthwhile to keep an open mind regarding new ideas and have at least a small fraction of researchers working somewhat away from the mainstream. This could possibly lead to new insights which have been missed by the more conventional mainstream approaches and could even finally provide a much awaited breakthrough. The collection of articles in this book should probably be viewed against such a backdrop. A few of the articles contained in the book deal with topics which are probably not mainstream. But all the speakers have presented their ideas clearly and in a proper setting, making many of the articles quite useful for a person who wants to obtain a bird's eye view. The connecting thread is essentially whether some aspects of quantum gravitational physics can lead to potentially observable effects or provide explanations for known effects. The book also contains a few overview articles of exceptional clarity. In particular I would like to mention the one by E Alvarez on quantum gravity, the one by L Smolin on loop quantum gravity and J Martin's article on the origin of cosmological perturbations. The rest of the articles are more focussed on possible quantum gravity phenomenology and discuss diverse topics such as astrophysical bounds of Lorentz violations, doubly special relativity and the role of quantum form in quantum gravity phenomenon. I thoroughly enjoyed reading

  3. X-Ray Calorimeter Arrays for Astrophysics

    Science.gov (United States)

    Kilbourne, Caroline A.

    2009-01-01

    High-resolution x-ray spectroscopy is a powerful tool for studying the evolving universe. The grating spectrometers on the XMM and Chandra satellites started a new era in x-ray astronomy, but there remains a need for instrumentation that can provide higher spectral resolution with high throughput in the Fe-K band (around 6 keV) and can enable imaging spectroscopy of extended sources, such as supernova remnants and galaxy clusters. The instrumentation needed is a broad-band imaging spectrometer - basically an x-ray camera that can distinguish tens of thousands of x-ray colors. The potential benefits to astrophysics of using a low-temperature calorimeter to determine the energy of an incident x-ray photon via measurement of a small change in temperature was first articulated by S. H. Moseley over two decades ago. In the time since, technological progress has been steady, though full realization in an orbiting x-ray telescope is still awaited. A low-temperature calorimeter can be characterized by the type of thermometer it uses, and three types presently dominate the field. The first two types are temperature-sensitive resistors - semiconductors in the metal-insulator transition and superconductors operated in the superconducting-normal transition. The third type uses a paramagnetic thermometer. These types can be considered the three generations of x-ray calorimeters; by now each has demonstrated a resolving power of 2000 at 6 keV, but only a semiconductor calorimeter system has been developed to spaceflight readiness. The Soft X-ray Spectrometer on Astro-H, expected to launch in 2013, will use an array of silicon thermistors with I-IgTe x-ray absorbers that will operate at 50 mK. Both the semiconductor and superconductor calorimeters have been implemented in small arrays, kilo-pixel arrays of the superconducting calorimeters are just now being produced, and it is anticipated that much larger arrays will require the non-dissipative advantage of magnetic thermometers.

  4. The Astrophysics of Strongly Interacting Systems

    Science.gov (United States)

    Nerella, Tejaswi Venumadhav

    This thesis presents investigations in four areas of theoretical astrophysics: the production of sterile neutrino dark matter in the early Universe, the evolution of small-scale baryon perturbations during the epoch of cosmological recombination, the effect of primordial magnetic fields on the redshifted 21-cm emission from the pre-reionization era, and the nonlinear stability of tidally deformed neutron stars. In the first part of the thesis, we study the asymmetry-driven resonant production of 7 keV-scale sterile neutrino dark matter in the primordial Universe at temperatures T >~ 100 MeV. We report final DM phase space densities that are robust to uncertainties in the nature of the quark-hadron transition. We give transfer functions for cosmological density fluctuations that are useful for N-body simulations. We also provide a public code for the production calculation. In the second part of the thesis, we study the instability of small-scale baryon pressure sound waves during cosmological recombination. We show that for relevant wavenumbers, inhomogenous recombination is driven by the transport of ionizing continuum and Lyman-alpha photons. We find a maximum growth factor less than ≈ 1.2 in 107 random realizations of initial conditions. The low growth factors are due to the relatively short duration of the recombination epoch. In the third part of the thesis, we propose a method of measuring weak magnetic fields, of order 10--19 G (or 10--21 G if scaled to the present day), with large coherence lengths in the inter galactic medium prior to and during the epoch of cosmic reionization. The method utilizes the Larmor precession of spin-polarized neutral hydrogen in the triplet state of the hyperfine transition. We perform detailed calculations of the microphysics behind this effect, and take into account all the processes that affect the hyperfine transition, including radiative decays, collisions, and optical pumping by Lyman-alpha photons. In the final part of

  5. Magneto-hydrodynamics Simulation in Astrophysics

    Science.gov (United States)

    Pang, Bijia

    2011-08-01

    Magnetohydrodynamics (MHD) studies the dynamics of an electrically conducting fluid under the influence of a magnetic field. Many astrophysical phenomena are related to MHD, and computer simulations are used to model these dynamics. In this thesis, we conduct MHD simulations of non-radiative black hole accretion as well as fast magnetic reconnection. By performing large scale three dimensional parallel MHD simulations on supercomputers and using a deformed-mesh algorithm, we were able to conduct very high dynamical range simulations of black hole accretion of Sgr A* at the Galactic Center. We find a generic set of solutions, and make specific predictions for currently feasible observations of rotation measure (RM). The magnetized accretion flow is subsonic and lacks outward convection flux, making the accretion rate very small and having a density slope of around -1. There is no tendency for the flows to become rotationally supported, and the slow time variability of th! e RM is a key quantitative signature of this accretion flow. We also provide a constructive numerical example of fast magnetic reconnection in a three-dimensional periodic box. Reconnection is initiated by a strong, localized perturbation to the field lines and the solution is intrinsically three-dimensional. Approximately 30% of the magnetic energy is released in an event which lasts about one Alfvén time, but only after a delay during which the field lines evolve into a critical configuration. In the co-moving frame of the reconnection regions, reconnection occurs through an X-like point, analogous to the Petschek reconnection. The dynamics appear to be driven by global flows rather than local processes. In addition to issues pertaining to physics, we present results on the acceleration of MHD simulations using heterogeneous computing systems te{shan2006heterogeneous}. We have implemented the MHD code on a variety of heterogeneous and multi-core architectures (multi-core x86, Cell, Nvidia and

  6. Astrophysics in the Era of Massive Time-Domain Surveys

    Science.gov (United States)

    Djorgovski, G.

    Synoptic sky surveys are now the largest data producers in astronomy, entering the Petascale regime, opening the time domain for a systematic exploration. A great variety of interesting phenomena, spanning essentially all subfields of astronomy, can only be studied in the time domain, and these new surveys are producing large statistical samples of the known types of objects and events for further studies (e.g., SNe, AGN, variable stars of many kinds), and have already uncovered previously unknown subtypes of these (e.g., rare or peculiar types of SNe). These surveys are generating a new science, and paving the way for even larger surveys to come, e.g., the LSST; our ability to fully exploit such forthcoming facilities depends critically on the science, methodology, and experience that are being accumulated now. Among the outstanding challenges, the foremost is our ability to conduct an effective follow-up of the interesting events discovered by the surveys in any wavelength regime. The follow-up resources, especially spectroscopy, are already and, for the predictable future, will be severely limited, thus requiring an intelligent down-selection of the most astrophysically interesting events to follow. The first step in that process is an automated, real-time, iterative classification of events, that incorporates heterogeneous data from the surveys themselves, archival and contextual information (spatial, temporal, and multiwavelength), and the incoming follow-up observations. The second step is an optimal automated event prioritization and allocation of the available follow-up resources that also change in time. Both of these challenges are highly non-trivial, and require a strong cyber-infrastructure based on the Virtual Observatory data grid, and the various astroinformatics efforts. Time domain astronomy is inherently an astronomy of telescope-computational systems, and will increasingly depend on novel machine learning and artificial intelligence tools

  7. VI European Summer School on Experimental Nuclear Astrophysics

    Science.gov (United States)

    The European Summer School on Experimental Nuclear Astrophysics has reached the sixth edition, marking the tenth year's anniversary. The spirit of the school is to provide a very important occasion for a deep education of young researchers about the main topics of experimental nuclear astrophysics. Moreover, it should be regarded as a forum for the discussion of the last-decade research activity. Lectures are focused on various aspects of primordial and stellar nucleosynthesis, including novel experimental approaches and detectors, indirect methods and radioactive ion beams. Moreover, in order to give a wide educational offer, some lectures cover complementary subjects of nuclear astrophysics such as gamma ray astronomy, neutron-induced reactions, short-lived radionuclides, weak interaction and cutting-edge facilities used to investigate nuclear reactions of interest for astrophysics. Large room is also given to young researcher oral contributions. Traditionally, particular attention is devoted to the participation of students from less-favoured countries, especially from the southern coast of the Mediterranean Sea. The school is organised by the Catania Nuclear Astrophysics research group with the collaboration of Dipartimento di Fisica e Astromomia - Università di Catania and Laboratori Nazionali del Sud - Istituto Nazionale di Fisica Nucleare.

  8. SETI at X-ray Energies - Parasitic Searches from Astrophysical Observations

    CERN Document Server

    Corbet, Robin H D

    2016-01-01

    If a sufficiently advanced civilization can either modulate the emission from an X-ray binary, or make use of the natural high luminosity to power an artificial transmitter, these can serve as good beacons for interstellar communication without involving excessive energy costs to the broadcasting civilization. In addition, the small number of X-ray binaries in the Galaxy considerably reduces the number of targets that must be investigated compared to searches in other energy bands. Low mass X-ray binaries containing neutron stars in particular are considered as prime potential natural and artificial beacons and high time resolution (better than 1ms) observations are encouraged. All sky monitors provide the capability of detecting brief powerful artificial signals from isolated neutron stars. New capabilities of X-ray astronomy satellites developed for astrophysical purposes are enabling SETI in new parameter regimes. For example, the X-ray Timing Explorer satellite provides the capability of exploring the sub...

  9. High Energy Studies of Astrophysical Dust

    Science.gov (United States)

    Corrales, Lia Racquel

    Astrophysical dust---any condensed matter ranging from tens of atoms to micron sized grains---accounts for about one third of the heavy elements produced in stars and disseminated into space. These tiny pollutants are responsible for producing the mottled appearance in the spray of light we call the "Milky Way." However these seemingly inert particles play a strong role in the physics of the interstellar medium, aiding star and planet formation, and perhaps helping to guide galaxy evolution. Most dust grains are transparent to X-ray light, leaving a signature of atomic absorption, but also scattering the light over small angles. Bright X-ray objects serendipitously situated behind large columns of dust and gas provide a unique opportunity to study the dust along the line of sight. I focus primarily on X-ray scattering through dust, which produces a diffuse halo image around a central point source. Such objects have been observed around X-ray bright Galactic binaries and extragalactic objects that happen to shine through the plane of the Milky Way. I use the Chandra X-ray Observatory, a space-based laboratory operated by NASA, which has imaging resolution ideal for studying X-ray scattering halos. I examine several bright X-ray objects with dust-free sight lines to test their viability as templates and develop a parametric model for the Chandra HETG point spread function (PSF). The PSF describes the instrument's imaging response to a point source, an understanding of which is necessary for properly measuring the surface brightness of X-ray scattering halos. I use an HETG observation of Cygnus X-3, one of the brightest objects available in the Chandra archive, to derive a dust grain size distribution. There exist degenerate solutions for the dust scattering halo, but with the aid of Bayesian analytics I am able to apply prior knowledge about the Cyg X-3 sight line to measure the relative abundance of dust in intervening Milky Way spiral arms. I also demonstrate how

  10. The astrophysics of the intracluster plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cavaliere, Alfonso [Univ. ‘Tor Vergata’, Via Ricerca Scientifica 1, 00133 Roma (Italy); INAF, Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio (Italy); Lapi, Andrea, E-mail: lapi@roma2.infn.it [Univ. ‘Tor Vergata’, Via Ricerca Scientifica 1, 00133 Roma (Italy); SISSA, Via Bonomea 265, 34136 Trieste (Italy)

    2013-12-20

    relationship between the detailed ICP profiles and the cosmological evolution of the containing DM potential wells. The results also provide the simplest baseline for disentangling a number of additional and intriguing physical processes superposed to the general equilibrium. The present Report is focused on the ICP physics as driven by the two-stage evolution of the containing DM halos. We extensively discuss the basic entropy pattern established by the cluster formation and development, and cover: the central entropy erosion produced by radiative cooling that competes with the intermittent energy inputs due to active galactic nuclei and mergers; outer turbulent support linked with weakening shocks and decreasing inflow through the virial boundary, causing reduced entropy production during the late stage of DM halo evolution; the development from high to low entropy levels throughout a typical cluster; perturbations of the equilibrium up to outright disruption due to deep impacts of infalling galaxy groups or collisions with comparable companion clusters; relativistic energy distributions of electrons accelerated during such events, producing extended radio emission by synchrotron radiation and contributing non thermal pressure support for the ICP. We conclude with discussing selected contributions from cluster astrophysics to cosmology at large, and by addressing how the ICP features and processes will constitute enticing targets for observations with the ongoing Planck mission, for upcoming instrumentation like ALMA and other ground-based radio observatories, and for the next-generation of X-ray satellites from ASTRO-H to eROSITA.

  11. Limits of Astrophysics with Gravitational-Wave Backgrounds

    Science.gov (United States)

    Callister, Thomas; Sammut, Letizia; Qiu, Shi; Mandel, Ilya; Thrane, Eric

    2016-07-01

    The recent Advanced LIGO detection of gravitational waves from the binary black hole GW150914 suggests there exists a large population of merging binary black holes in the Universe. Although most are too distant to be individually resolved by advanced detectors, the superposition of gravitational waves from many unresolvable binaries is expected to create an astrophysical stochastic background. Recent results from the LIGO and Virgo Collaborations show that this astrophysical background is within reach of Advanced LIGO. In principle, the binary black hole background encodes interesting astrophysical properties, such as the mass distribution and redshift distribution of distant binaries. However, we show that this information will be difficult to extract with the current configuration of advanced detectors (and using current data analysis tools). Additionally, the binary black hole background also constitutes a foreground that limits the ability of advanced detectors to observe other interesting stochastic background signals, for example, from cosmic strings or phase transitions in the early Universe. We quantify this effect.

  12. Experimental astrophysics with high power lasers and Z pinches

    Energy Technology Data Exchange (ETDEWEB)

    Remington, B A; Drake, R P; Ryutov, D D

    2004-12-10

    With the advent of high energy density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, mm-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors; equations of state relevant to planetary interiors; strong shock driven nonlinear hydrodynamics and radiative dynamics, relevant to supernova explosions and subsequent evolution; protostellar jets and high Mach-number flows; radiatively driven molecular clouds and nonlinear photoevaporation front dynamics; and photoionized plasmas relevant to accretion disks around compact objects, such as black holes and neutron stars.

  13. Applications of the Trojan Horse method in nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Spitaleri, Claudio, E-mail: spitaleri@lns.infn.it [Dipartimento di Fisica e Astronomia, Università di Catania, Catania, Italy and Laboratori Nazionali del Sud-INFN, Catania (Italy)

    2015-02-24

    The study of the energy production in stars and related nucleosyntesis processes requires increasingly precise knowledge of the nuclear reaction cross section and reaction rates at interaction energy. In order to overcome the experimental difficulties, arising from small cross-sections involved in charge particle induced reactions at astrophysical energies, and from the presence of electron screening, it was necessary to introduce indirect methods. Trough these methods it is possible to measure cross sections at very small energies and retrieve information on electron screening effect when ultra-low energy direct measurements are available. The Trojan Horse Method (THM) represents the indirect technique to determine the bare nucleus astrophysical S-factor for reactions between charged particles at astrophysical energies. The basic theory of the THM is discussed in the case of non-resonant.

  14. AstroBlend: An Astrophysical Visualization Package for Blender

    CERN Document Server

    Naiman, J P

    2016-01-01

    The rapid growth in scale and complexity of both computational and observational astrophysics over the past decade necessitates efficient and intuitive methods for examining and visualizing large datasets. Here, I present {\\it AstroBlend}, an open-source Python library for use within the three dimensional modeling software, {\\it Blender}. While {\\it Blender} has been a popular open-source software among animators and visual effects artists, in recent years it has also become a tool for visualizing astrophysical datasets. {\\it AstroBlend} combines the three dimensional capabilities of {\\it Blender} with the analysis tools of the widely used astrophysical toolset, {\\it yt}, to afford both computational and observational astrophysicists the ability to simultaneously analyze their data and create informative and appealing visualizations. The introduction of this package includes a description of features, work flow, and various example visualizations. A website - www.astroblend.com - has been developed which incl...

  15. The limits of astrophysics with gravitational wave backgrounds

    CERN Document Server

    Callister, Thomas; Thrane, Eric; Qiu, Shi; Mandel, Ilya

    2016-01-01

    The recent Advanced LIGO detection of gravitational waves from the binary black hole GW150914 suggests there is a large population of merging binary black holes in the Universe. Although most are too distant to be individually resolved by advanced detectors, the superposition of gravitational waves from many unresolvable binaries is expected to create an astrophysical stochastic background. Recent results from the LIGO/Virgo collaboration show that this astrophysical background is within reach of Advanced LIGO. In principle, the binary black hole background encodes interesting astrophysical properties, such as the mass distribution and redshift distribution of distant binaries. However, we show that this information will be difficult to extract with the current configuration of advanced detectors (and using current data analysis tools). Additionally, the binary black hole background also constitutes a foreground that limits the ability of advanced detectors to observe other interesting stochastic background s...

  16. VALD - an atomic and molecular database for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Heiter, U; Barklem, P; Kochukhov, O; Piskunov, N [Department of Astronomy and Space Physics, Uppsala University (Sweden); Fossati, L; Obbrugger, M; Stuetz, Ch; Weiss, W W [Institute of Astronomy, University of Vienna (Austria); Kildiyarova, R [Institute of Spectroscopy, Russian Academy of Sciences, Moscow region, Troitsk (Russian Federation); Kupka, F [Max-Planck-Institute for Astrophysics, Garching (Germany); Plez, B [Universite Montpellier II, GRAAL, CNRS - UMR 5024 (France); Ryabchikova, T [Institute of Astronomy, Russian Academy of Sciences, Moscow (Russian Federation); Stempels, H C [School of Physics and Astronomy, University of St Andrews, Scotland (United Kingdom)], E-mail: ulrike@astro.uu.se

    2008-10-15

    The VALD database of atomic and molecular data aims to ensure a robust and consistent analysis of astrophysical spectra. We offer a convenient e-mail and web-based user interface to a vast collection of spectral line parameters for all chemical elements and in the future also for molecules. An international team is working on the following tasks: collecting line parameters from relevant theoretical and experimental publications, computing line parameters, evaluating the data quality by comparison of similar data from different sources and by comparison with astrophysical observations, and incorporating the data into VALD. A unique feature of VALD is its capability to provide the most comprehensive spectral line lists for specific astrophysical plasma conditions defined by the user.

  17. KROME - a package to embed chemistry in astrophysical simulations

    CERN Document Server

    Grassi, T; Schleicher, D R G; Prieto, J; Seifried, D; Simoncini, E; Gianturco, F A

    2013-01-01

    Chemistry plays a key role in many astrophysical situations, and therefore needs to be included in astrophysical simulations modelling such environments. In particular, the chemical evolution regulates the cooling, and the thermal properties of the gas, which are relevant during gravitational collapse, the evolution of disks and the fragmentation process. At the same time, the chemistry of the gas also determines the observational appearance, in particular with respect to the emission through atomic, ionic or molecular lines. In order to simplify the usage of chemical networks in large numerical simulations, we present the chemistry package KROME, consisting of a Python pre-processor which generates a subroutine for the solution of chemical networks which can be embedded in any numerical code. For the solution of the rate equations, we make use of the high-order solver DLSODES, which was shown to be both accurate and efficient for sparse networks, which are typical in astrophysical applications. KROME also pr...

  18. International Workshop on Redshift Mechanisms in Astrophysics and Cosmology

    CERN Document Server

    López-Corredoira, M

    2007-01-01

    An extraordinary event took place recently in Ireland. A group of independent and professional researchers met to discuss an old heterodox topic with important consequences in astrophysics and, especially, in cosmology: possible causes of the redshifts in the spectra of astrophysical objects other than a Doppler or expanding universe mechanism. Many decades of work have been devoted to this kind of research, most of it forgotten by the greater part of the astrophysical community nowadays. But the question is still open, the debate is still alive, as was shown by the participants in the present Workshop. There is no smoke without fire, and the existence of many facts and theories on alternative origins of redshifts may point to some new pathways in physics that deserve further attention. This was precisely the aim of this meeting. (...)

  19. Astrophysically Triggered Searches for Gravitational Waves: Status and Prospects

    CERN Document Server

    Abbott, B; Adhikari, R; Ajith, P; Allen, B; Allen, G; Amin, R; Anderson, S B; Anderson, W G; Arain, M A; Araya, M; Armandula, H; Armor, P; Aso, Y; Aston, S; Aufmuth, P; Aulbert, C; Babak, S; Ballmer, S; Bantilan, H; Barish, B C; Barker, C; Barker, D; Barr, B; Barriga, P; Barton, M A; Bastarrika, M; Bayer, K; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Biswas, R; Black, E; Blackburn, K; Blackburn, L; Blair, D; Bland, B; Bodiya, T P; Bogue, L; Bork, R; Boschi, V; Bose, S; Brady, P R; Braginsky, V B; Brau, J E; Brinkmann, M; Brooks, A; Brown, D A; Brunet, G; Bullington, A; Buonanno, A; Burmeister, O; Byer, R L; Cadonati, L; Cagnoli, G; Camp, J B; Cannizzo, J; Cannon, K; Cao, J; Cardenas, L; Casebolt, T; Castaldi, G; Cepeda, C; Chalkley, E; Charlton, P; Chatterji, S; Chelkowski, S; Chen, Y; Christensen, N; Clark, D; Clark, J; Cokelaer, T; Conte, R; Cook, D; Corbitt, T; Coyne, D; Creighton, J D E; Cumming, A; Cunningham, L; Cutler, R M; Dalrymple, J; Danzmann, K; Davies, G; De Bra, D; Degallaix, J; Degree, M; Dergachev, V; Desai, S; DeSalvo, R; Dhurandhar, S; Daz, M; Dickson, J; Dietz, A; Donovan, iF; Dooley, K L; Doomes, E E; Drever, R W P; Duke, I; Dumas, J C; Dupuis, R J; Dwyer, J G; Echols, C; Eer, A; Ehrens, P; Espinoza, E; Etzel, T; Evans, T; Fairhurst, S; Fan, Y; Fazi, D; Fehrmann, H; Fejer, M M; Finn, L S; Flasch, K; Fotopoulos, N; Freise, A; Frey, R; Fricke, T; Fritschel, P; Frolov, V V; Fyffe, M; Garofoli, J; Gholami, I; Giaime, J A; Giampanis, S; Giardina, K D; Goda, K; Goetz, E; Goggin, L; González, G; Gossler, S; Gouaty, R; Grant, A; Gras, S; Gray, aC; Gray, M; Greenhalgh, R J S; Gretarsson, A M; Grimaldi, F; Grosso, R; Grote, H; Grünewald, S; Günther, M; Gustafson, E K; Gustafson, R; Hage, B; Hallam, J M; Hammer, D; Hanna, C; Hanson, J; Harms, J; Harry, G; Harstad, E; Hayama, K; Hayler, T; Heefner, J; Heng, I S; Hennessy, M; Heptonstall, A; Hewitson, M; Hild, S; Hirose, E; Hoak, D; Hosken, D; Hough, J; Huttner, S H; Ingram, D; Ito, M; Ivanov, A; Johnson, B; Johnson, W W; Jones, D I; Jones, G; Jones, R; Ju, L; Kalmus, Peter Ignaz Paul; Kalogera, V; Kamat, S; Kanner, J; Kasprzyk, D; Katsavounidis, E; Kawabe, K; Kawamura, S; Kawazoe, F; Kells, W; Keppel, D G; Khalili, F Ya; Khan, R; Khazanov, E; Kim, C; King, P; Kissel, J S; Klimenko, S; Kokeyama, K; Kondrashov, V; Kopparapu, R K; Kozak, D; Kozhevatov, I; Krishnan, B; Kwee, P; Lam, P K; Landry, M; Lang, M M; Lantz, B; Lazzarini, A; Lei, M; Leindecker, N; Leonhardt, V; Leonor, I; Libbrecht, K; Lin, H; Lindquist, P; Lockerbie, N A; Lodhia, D; Lormand, M; Lu, P; Lubinski, M; Lucianetti, A; Luck, H; Machenschalk, B; MacInnis, M; Mageswaran, M; Mailand, K; Mandic, V; Mrka, S; Mrka, Z; Markosyan, A; Markowitz, J; Maros, aaE; Martin, I; Martin, R M; Marx, J N; Mason, K; Matichard, F; Matone, L; Matzner, R; Mavalvala, N; McCarthy, R; McClelland, D E; McGuire, S C; McHugh, M; McIntyre, G; McIvor, G; McKechan, D; McKenzie, K; Meier, T; Melissinos, A; Mendell, G; Mercer, R A; Meshkov, S; Messenger, C J; Meyers, D; Miller, J; Minelli, J; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Miyakawa, O; Moe, B; Mohanty, S; Moreno, G; Mossavi, K; Mow Lowry, C; Müller, G; Mukherjee, S; Mukhopadhyay, H; Muller-Ebhardt, H; Munch, J; Murray, P; Myers, E; Myers, J; Nash, T; Nelson, J; Newton, G; Nishizawa, A; Numata, K; O'Dell, J; Ogin, G; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pan, Y; Pankow, C; Papa, M A; Parameshwaraiah, V; Patel, P; Pedraza, M; Penn, S; Perreca, A; Petrie, T; Pinto, I M; Pitkin, M; Pletsch, H J; Plissi, M V; Postiglione, F; Principe, M; Prix, R; Quetschke, V; Raab, F; Rabeling, D S; Radkins, H; Rainer, N; Rakhmanov, M; Ramsunder, M; Rehbein, H; Reid, S; Reitze, D H; Riesen, R; Riles, K; Rivera, B; Robertson, N A; Robinson, C; Robinson, E L; Roddy, S; Rodríguez, A; Rogan, A M; Rollins, J; Romano, J D; Romie, J; Route, R; Rowan, S; Rüdiger, A; Ruet, L; Russell, P; Ryan, K; Sakata, S; Samidi, M; Sanchodela Jordana, L; Sandberg, V; Sannibale, V; Saraf, S; Sarin, P; Sathyaprakash, B S; Sato, S; Saulson, P R; Savage, R; Savov, P; Schediwy, S W; Schilling, R; Schnabel, R; Schofield, R; Schutz, B F; Schwinberg, P; Scott, S M; Searle, A C; Sears, B; Seifert, F; Sellers, D; Sengupta, A S; Shawhan, P; Shoemaker, D H; Sibley, A; Siemens, X; Sigg, D; Sinha, S; Sintes, A M; Slagmolen, B J J; Slutsky, J; Smith, J R; Smith, M R; Smith, N D; Somiya, K; Sorazu, B; Stein, L C; Stochino, A; Stone, R; Strain, K A; Strom, D M; Stuver, A; Summerscales, T Z; Sun, K X; Sung, M; Sutton, P J; Takahashi, H; Tanner, D B; Taylor, R; Taylor, R; Thacker, J; Thorne, K A; Thorne, K S; Thüring, A; Tokmakov, K V; Torres, C; Torrie, C; Traylor, G; Trias, M; Tyler, W; Ugolini, D; Ulmen, J; Urbanek, K; Vahlbruch, H; Van Den Broeck, C; vander Sluys, M; Vass, S; Vaulin, R; Vecchio, A; Veitch, J; Veitch, P; Villar, A; Vorvick, C; Vyachanin, S P; Waldman, S J; Wallace, L; Ward, H; Ward, R; Weinert, M; Weinstein, A; Weiss, R; Wen, S; Wette, K; Whelan, J T; Whitcomb, S E; Whiting, B F; Wilkinson, C; Willems, P A; Williams, H R; Williams, L; Willke, B; Wilmut, I; Winkler, W; Wipf, C C; Wiseman, A G; Woan, G; Wooley, R; Worden, J; Wu, W; Yakushin, I; Yamamoto, H; Yan, Z; Yoshida, S; Zanolin, M; Zhang, J; Zhang, L; Zhao, C; Zotov, N; Zucker, M; Zweizig, J

    2008-01-01

    In gravitational-wave detection, special emphasis is put onto searches that focus on cosmic events detected by other types of astrophysical observatories. The astrophysical triggers, e.g. from gamma-ray and X-ray satellites, optical telescopes and neutrino observatories, provide a trigger time for analyzing gravitational wave data coincident with the event. In certain cases the expected frequency range, source energetics, directional and progenitor information is also available. Beyond allowing the recognition of gravitational waveforms with amplitudes closer to the noise floor of the detector, these triggered searches should also lead to rich science results even before the onset of Advanced LIGO. In this paper we provide a broad review of LIGO's astrophysically triggered searches and the sources they target.

  20. Applications of the Trojan Horse method in nuclear astrophysics

    Science.gov (United States)

    Spitaleri, Claudio

    2015-02-01

    The study of the energy production in stars and related nucleosyntesis processes requires increasingly precise knowledge of the nuclear reaction cross section and reaction rates at interaction energy. In order to overcome the experimental difficulties, arising from small cross-sections involved in charge particle induced reactions at astrophysical energies, and from the presence of electron screening, it was necessary to introduce indirect methods. Trough these methods it is possible to measure cross sections at very small energies and retrieve information on electron screening effect when ultra-low energy direct measurements are available. The Trojan Horse Method (THM) represents the indirect technique to determine the bare nucleus astrophysical S-factor for reactions between charged particles at astrophysical energies. The basic theory of the THM is discussed in the case of non-resonant.

  1. AHEAD: Integrated Activities in the High Energy Astrophysics Domain

    Science.gov (United States)

    Piro, Luigi; Natalucci, Lorenzo; Ahead Consortium

    2015-09-01

    AHEAD (Integrated Activities in the High Energy Astrophysics Domain) is a forthcoming project approved in the framework of the European Horizon 2020 program (Research Infrastructures for High Energy Astrophysics). The overall objective of AHEAD is to integrate national efforts in high-energy Astrophysics and to promote the domain at the European level, to keep its community at the cutting edge of science and technology and ensure that space observatories for high-energy astrophysics, with particular regard to Athena, are at the state of the art. AHEAD will integrate key research infrastructures for on-ground test and calibration of space-based sensors and electronics and promote their coordinated use. In parallel, the best facilities for data analysis of high-energy astrophysical observatories will be made available to the European community. The technological development will focus on the improvement of selected critical technologies, background modeling, cross calibration, and feasibility studies of space-based instrumentation for the benefit of future high energy missions like Athena, and the best exploitation of existing observatories. AHEAD will support the community via grants for collaborative studies, dissemination of results, and promotion of workshops. A strong public outreach package will ensure that the domain is well publicized at national, European and International level. Networking, joint research activities and access to infrastructures as devised in AHEAD, will serve to establish strong connections between institutes and industry to create the basis for a more rapid advancement of high-energy astrophysical science, space oriented instrumentation and cutting-edge sensor technology in Europe. This enables the development of new technologies and the associated growth of the European technology market with a dedicated technology innovation package, as well as the creation of a new generation of researchers.

  2. Excitation of compound states in the subsystems as indirect tool in nuclear astrophysics

    Directory of Open Access Journals (Sweden)

    Tribble R.E.

    2010-03-01

    Full Text Available Astrophysical reactions proceeding through compound states represent one of the crucial part of nuclear astrophysics. However, due to the presence of the Coulomb barrier, it is often very difficult or even impossible to obtain the astrophysical S (E factor from measurements in the laboratory at astrophysically relevant energies. The Trojan Horse method (THM provides a unique tool to obtain the information about resonant astrophysical reactions at astrophysically relevant energies. Here the theory and application of the THM for the resonant reactions is addressed.

  3. Mini-conference and Related Sessions on Laboratory Plasma Astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Hantao Ji

    2004-02-27

    This paper provides a summary of some major physics issues and future perspectives discussed in the Mini-Conference on Laboratory Plasma Astrophysics. This Mini-conference, sponsored by the Topical Group on Plasma Astrophysics, was held as part of the American Physical Society's Division of Plasma Physics 2003 Annual Meeting (October 27-31, 2003). Also included are brief summaries of selected talks on the same topic presented at two invited paper sessions (including a tutorial) and two contributed focus oral sessions, which were organized in coordination with the Mini-Conference by the same organizers.

  4. Numerical Simulations and Diagnostics in Astrophysics:. a Few Magnetohydrodynamics Examples

    Science.gov (United States)

    Peres, Giovanni; Bonito, Rosaria; Orlando, Salvatore; Reale, Fabio

    2007-12-01

    We discuss some issues related to numerical simulations in Astrophysics and, in particular, to their use both as a theoretical tool and as a diagnostic tool, to gain insight into the physical phenomena at work. We make our point presenting some examples of Magneto-hydro-dynamic (MHD) simulations of astrophysical plasmas and illustrating their use. In particular we show the need for appropriate tools to interpret, visualize and present results in an adequate form, and the importance of spectral synthesis for a direct comparison with observations.

  5. Technology maturation process: the NASA Strategic Astrophysics Technology (SAT) program

    Science.gov (United States)

    Perez, Mario R.; Pham, Bruce T.; Lawson, Peter R.

    2014-08-01

    In 2009 the Astrophysics Division at NASA Headquarters established the Strategic Astrophysics Technology (SAT) solicitation as a new technology maturation program to fill the needed gap for mid-Technology Readiness Level (TRL) levels (3≤ TRL <6). In three full proposal selection cycles since the inception of this program, more than 40 investigations have been selected, many meritorious milestones have been met and advances have been achieved. In this paper, we review the process of establishing technology priorities, the management of technology advancements and milestones, and the incipient success of some of these investigations in light of the need of future space missions.

  6. Formation of dense, electromagnetically accelerated plasma for laboratory astrophysics

    Directory of Open Access Journals (Sweden)

    Adachi K.

    2013-11-01

    Full Text Available We proposed tapered pinch discharge as a measure to conduct laboratory astrophysics experiments. Basic behaviors of the plasma have been characterized using a prototype device. Results show that the plasma flux and velocity depend on initial gas density, discharge current and taper geometry. Those behaviors can be illustrated with a simple model considering the pinching dynamics of the current sheet based on a 1 dimensional (1-D equation of motion. Achievable value of the tapered pinch plasma is estimated and compared with required plasma parameters based on scaling parameters for laboratory astrophysics.

  7. Direct Reactions with Exotic Nuclei, Nuclear Structure and Astrophysics

    CERN Document Server

    Baur, G

    2006-01-01

    Intermediate energy Coulomb excitation and dissociation is a useful tool for nuclear structure and astrophysics studies. Low-lying strength in nuclei far from stability was discovered by this method. The effective range theory for low-lying strength in one-neutron halo nuclei is summarized and extended to two-neutron halo nuclei. This is of special interest in view of recent rather accurate experimental results on the low-lying electric dipole strength in $^{11}$Li. Another indirect approach to nuclear astrophysics is the Trojan horse method. It is pointed out that it is a suitable tool to investigate subthreshold resonances.

  8. The 2050 Decadal Survey of Astronomy and Astrophysics

    Science.gov (United States)

    Longair, Malcolm

    2011-05-01

    Astronomy, Astrophysics and Cosmology have changed out of all recognition over the last 40 years. The lecture will review some of the key scientific, technological and sociological changes which have contributed to that revolution and seek to understand the issues of maintaining that drive for discovery and understanding over the next 40 years. Some science objectives are well defined, but others may need new concepts, unexpected discoveries and quite a bit of good luck. A personal perspective will be presented on topics which the community should take seriously for the advance of astronomy and astrophysics and the role it can play for the betterment of society.

  9. Storage ring mass spectrometry for nuclear structure and astrophysics research

    Science.gov (United States)

    Zhang, Y. H.; Litvinov, Yu A.; Uesaka, T.; Xu, H. S.

    2016-07-01

    In the last two and a half decades ion storage rings have proven to be powerful tools for precision experiments with unstable nuclides in the realm of nuclear structure and astrophysics. There are presently three storage ring facilities in the world at which experiments with stored radioactive ions are possible. These are the ESR in GSI, Darmstadt/Germany, the CSRe in IMP, Lanzhou/China, and the R3 storage ring in RIKEN, Saitama/Japan. In this work, an introduction to the facilities is given. Selected characteristic experimental results and their impact in nuclear physics and astrophysics are presented. Planned technical developments and the envisioned future experiments are outlined.

  10. A Lightweight, Precision-Deployable, Optical Bench for High Energy Astrophysics Missions

    Science.gov (United States)

    Danner, Rolf; Dailey, D.; Lillie, C.

    2011-09-01

    The small angle of total reflection for X-rays, forcing grazing incidence optics with large collecting areas to long focal lengths, has been a fundamental barrier to the advancement of high-energy astrophysics. Design teams around the world have long recognized that a significant increase in effective area beyond Chandra and XMM-Newton requires either a deployable optical bench or separate X-ray optics and instrument module on formation flying spacecraft. Here, we show that we have in hand the components for a lightweight, precision-deployable optical bench that, through its inherent design features, is the affordable path to the next generation of imaging high-energy astrophysics missions. We present our plans for a full-scale engineering model of a deployable optical bench for Explorer-class missions. We intend to use this test article to raise the technology readiness level (TRL) of the tensegrity truss for a lightweight, precision-deployable optical bench for high-energy astrophysics missions from TRL 3 to TRL 5 through a set of four well-defined technology milestones. The milestones cover the architecture's ability to deploy and control the focal point, characterize the deployed dynamics, determine long-term stability, and verify the stowed load capability. Our plan is based on detailed design and analysis work and the construction of a first prototype by our team. Building on our prior analysis and the high TRL of the architecture components we are ready to move on to the next step. The key elements to do this affordably are two existing, fully characterized, flight-quality, deployable booms. After integrating them into the test article, we will demonstrate that our architecture meets the deployment accuracy, adjustability, and stability requirements. The same test article can be used to further raise the TRL in the future.

  11. The X-Ray Surveyor mission concept study: forging the path to NASA astrophysics 2020 decadal survey prioritization

    Science.gov (United States)

    Gaskin, Jessica; Özel, Feryal; Vikhlinin, Alexey

    2016-07-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  12. The X-Ray Surveyor Mission Concept Study: Forging the Path to NASA Astrophysics 2020 Decadal Survey Prioritization

    Science.gov (United States)

    Gaskin, Jessica; Ozel, Feryal; Vikhlinin, Alexey

    2016-01-01

    The X-Ray Surveyor mission concept is unique among those being studied for prioritization in the NASA Astrophysics 2020 Decadal Survey. The X-Ray Surveyor mission will explore the high-energy Universe; providing essential and complimentary observations to the Astronomy Community. The NASA Astrophysics Roadmap (Enduring Quests, Daring Visions) describes the need for an X-Ray Observatory that is capable of addressing topics such as the origin and growth of the first supermassive black holes, galaxy evolution and growth of the cosmic structure, and the origin and evolution of the stars that make up our Universe. To address these scientifically compelling topics and more, an Observatory that exhibits leaps in capability over that of previous X-Ray Observatories in needed. This paper describes the current status of the X-Ray Surveyor Mission Concept Study and the path forward, which includes scientific investigations, technology development, and community participation.

  13. Time Series Explorer

    Science.gov (United States)

    Loredo, Thomas

    The key, central objectives of the proposed Time Series Explorer project are to develop an organized collection of software tools for analysis of time series data in current and future NASA astrophysics data archives, and to make the tools available in two ways: as a library (the Time Series Toolbox) that individual science users can use to write their own data analysis pipelines, and as an application (the Time Series Automaton) providing an accessible, data-ready interface to many Toolbox algorithms, facilitating rapid exploration and automatic processing of time series databases. A number of time series analysis methods will be implemented, including techniques that range from standard ones to state-of-the-art developments by the proposers and others. Most of the algorithms will be able to handle time series data subject to real-world problems such as data gaps, sampling that is otherwise irregular, asynchronous sampling (in multi-wavelength settings), and data with non-Gaussian measurement errors. The proposed research responds to the ADAP element supporting the development of tools for mining the vast reservoir of information residing in NASA databases. The tools that will be provided to the community of astronomers studying variability of astronomical objects (from nearby stars and extrasolar planets, through galactic and extragalactic sources) will revolutionize the quality of timing analyses that can be carried out, and greatly enhance the scientific throughput of all NASA astrophysics missions past, present, and future. The Automaton will let scientists explore time series - individual records or large data bases -- with the most informative and useful analysis methods available, without having to develop the tools themselves or understand the computational details. Both elements, the Toolbox and the Automaton, will enable deep but efficient exploratory time series data analysis, which is why we have named the project the Time Series Explorer. Science

  14. Gravitational Wave Astrophysics: Opening the New Frontier

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    A new era in astronomy will begin when the gravitational wave window onto the universe opens in approx. 5 years, as ground-based detectors make the first detections in the high-frequency regime. Since the universe is nearly transparent to gravitational waves, these signals carry direct information about their sources - such as masses, spins, luminosity distances, and orbital parameters - through dense, obscured regions across cosmic time. This talk will explore gravitational waves as cosmic messengers, highlighting key sources and opportunities for multi-messenger astronomy across the gravitational wave spectrum.

  15. Visualizing Astrophysical N-body Systems

    CERN Document Server

    Dubinski, John

    2008-01-01

    I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic dynamics. These techniques are incorporated into a specialized particle visualization software library called MYRIAD that is designed to render images within large parallel N-body simulations as they run. I present several case studies that explore the application of these methods to animations of star clusters, interacting galaxies and cosmological structure formation.

  16. Mining knowledge in astrophysical massive data sets

    International Nuclear Information System (INIS)

    Modern scientific data mainly consist of huge data sets gathered by a very large number of techniques and stored in much diversified and often incompatible data repositories. More in general, in the e-science environment, it is considered as a critical and urgent requirement to integrate services across distributed, heterogeneous, dynamic 'virtual organizations' formed by different resources within a single enterprise. In the last decade, Astronomy has become an immensely data-rich field due to the evolution of detectors (plates to digital to mosaics), telescopes and space instruments. The Virtual Observatory approach consists of the federation under common standards of all astronomical archives available worldwide, as well as data analysis, data mining and data exploration applications. The main drive behind such an effort is that once the infrastructure is complete, it will allow a new type of multi-wavelength, multi-epoch science, which can only be barely imagined. Data mining, or knowledge discovery in databases, while being the main methodology to extract the scientific information contained in such Massive Data Sets (MDS), poses crucial problems since it has to orchestrate complex problems posed by transparent access to different computing environments, scalability of algorithms, reusability of resources, etc. In the present paper we summarize the present status of the MDS in the Virtual Observatory and what is currently done and planned to bring advanced data mining methodologies in the case of the DAME (DAta Mining and Exploration) project.

  17. Development of a Laue lens for nuclear astrophysics

    International Nuclear Information System (INIS)

    In this work, a new type of gamma-ray telescope is presented. It features a crystal diffraction lens that concentrates photons from a large photon collecting area onto a small detector. In such a Laue lens, a large number of crystals are disposed on concentric rings; each crystal can be considered as a little mirror which deviates gamma-rays through Bragg diffraction from the incident beam onto a common focal spot. The principle of the Laue lens for astrophysics was demonstrated with the balloon mission CLAIRE. The objective of this work was to develop the Laue Lens concept into a sensitive, space qualified optics for a future satellite mission. This contribution consisted of two main facets: a) finding appropriate crystal materials and improving the performance of the diffracting crystals, and b) develop a prototype segment for a space qualified lens. Exploring new diffracting media and improving the performance of individual crystals implied the development of numerical simulations of the diffraction process for various types of mosaic and CDP (Curved Diffraction Plane) crystals. These simulations were used to select suitable crystals to be grown and to be tested. Two different X-ray facilities were used to probe the crystalline quality of candidate materials: the European Synchrotron Radiation Facility (ESRF, France) and the high neutron flux reactor at ILL (France). During 10 beam-runs (and a total of 3 months of measurement), a large number of samples were tested, including Ag, Ir, Pt, Au, Pb, Rh, AsGa, SiGe, and Cu crystals. Outstanding performances were established for gold and silver crystals (>500 keV), Cu and Ge (300-500 keV) crystals and SiGe CDP (<300 keV) crystal. The second facet of this work consisted of designing, manufacturing and characterizing a prototype lens segment. This R and D program was completed in collaboration with the CNES and Thales Alenia Space. For a representative sample of metal and semiconductor crystals that were mounted on the

  18. Cosmological observations as a probe of fundamental physics and astrophysics

    Science.gov (United States)

    Ferraro, Simone

    The unifying theme of this dissertation is using cosmological observations as a tool to discover new physics and astrophysics. The first part focuses on the effects of primordial non-Gaussianity on the large-scale distribution of dark matter halos. The statistical properties of the primordial fluctuation contain a wealth of information about the Universe's early moments, and these properties are imprinted on the late-time distribution of matter. The first chapter serves as an introduction to the effects of non-Gaussianity on halo bias, summarizing previous work and extending it to the cubic local model (the gNL model). Chapter 2 generalizes some of the techniques of Chapter 1, allowing for the calculation of halo bias with arbitrary initial conditions, while Chapter 3 shows the relationship between the seemingly different techniques existing in the literature. Detailed forecasts for upcoming surveys are presented in Chapter 4, including the effect of marginalization over shot-noise and Gaussian part of the bias, photometric redshifts uncertainties and multi-tracer analysis to reduce the effect of cosmic variance. The second part contains work on two secondary anisotropies of the Cosmic Microwave Background radiation (CMB), namely the Integrated Sachs-Wolfe (ISW) effect and the kinetic Sunyaev-Zel'dovich (kSZ) effect. The late-time ISW effect arises because of decay of the large-scale gravitational potential due to the accelerated expansion and is therefore a powerful probe of dark energy. Chapter 5 presents a new detection of the ISW effect, using WISE galaxies and AGN as tracers of the gravitational potential, whose bias is measured in cross-correlation with CMB lensing maps. An appendix discusses the contamination of this measurement due to the linear part of the kSZ effect, the Doppler shift of photon energy due to scattering off coherently moving electrons. The last chapter explores the prospects of detecting the kSZ signal from sources for which accurate

  19. Nuclear astrophysics with tagged photons: NEPTUN @ S-DALINAC, Darmstadt

    Science.gov (United States)

    Schnorrenberger, L.; Sonnabend, K.; Glorius, J.; Löher, B.; Pietralla, N.; Savran, D.; Simon, V.; Wälzlein, C.

    2010-01-01

    Tagged photons can be used to study astrophysically relevant cross sections with highest energy resolution. The tagging facility NEPTUN at the S-DALINAC, Darmstadt, Germany, is presented and it is demonstrated how NEPTUN can be used to study short-lived branching nuclei of s-process nucleosynthesis.

  20. Nuclear astrophysics with tagged photons: NEPTUN-DALINAC, Darmstadt

    Energy Technology Data Exchange (ETDEWEB)

    Schnorrenberger, L; Sonnabend, K; Glorius, J; Loeher, B; Pietralla, N; Savran, D; Simon, V; Waelzlein, C, E-mail: schnorrenberger@ikp.tu-darmstadt.d [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)

    2010-01-01

    Tagged photons can be used to study astrophysically relevant cross sections with highest energy resolution. The tagging facility NEPTUN at the S-DALINAC, Darmstadt, Germany, is presented and it is demonstrated how NEPTUN can be used to study short-lived branching nuclei of s-process nucleosynthesis.