Enabling Virtual Access to Latin-American Southern Observatories

NASA Astrophysics Data System (ADS)

Filippi, G.

2010-12-01

EVALSO (Enabling Virtual Access to Latin-American Southern Observatories) is an international consortium of nine astronomical organisations and research network operators, part-funded under the European Commission FP7, to create and exploit high-speed bandwidth connections to South American observatories. A brief description of the project is presented. The EVALSO Consortium inaugurated a fibre link between the Paranal Observatory and international networks on 4 November 2010 capable of 10 Gigabit per second.

The Virtual Solar Observatory and the Heliophysics Meta-Virtual Observatory

NASA Astrophysics Data System (ADS)

Gurman, J. B.; Hourclé, J. A.; Bogart, R. S.; Tian, K.; Hill, F.; Suàrez-Sola, I.; Zarro, D. M.; Davey, A. R.; Martens, P. C.; Yoshimura, K.; Reardon, K. M.

2006-12-01

The Virtual Solar Observatory (VSO) has survived its infancy and provides metadata search and data identification for measurements from 45 instrument data sets held at 12 online archives, as well as flare and coronal mass ejection (CME) event lists. Like any toddler, the VSO is good at getting into anything and everything, and is now extending its grasp to more data sets, new missions, and new access methods using its application programming interface (API). We discuss and demonstrate recent changes, including developments for STEREO and SDO, and an IDL-callable interface for the VSO API. We urge the heliophysics community to help civilize this obstreperous youngster by providing input on ways to make the VSO even more useful for system science research in its role as part of the growing cluster of Heliophysics Virtual Observatories.

Armagh Observatory - Historic Building Information Modelling for Virtual Learning in Building Conservation

NASA Astrophysics Data System (ADS)

Murphy, M.; Chenaux, A.; Keenaghan, G.; GIbson, V..; Butler, J.; Pybusr, C.

2017-08-01

In this paper the recording and design for a Virtual Reality Immersive Model of Armagh Observatory is presented, which will replicate the historic buildings and landscape with distant meridian markers and position of its principal historic instruments within a model of the night sky showing the position of bright stars. The virtual reality model can be used for educational purposes allowing the instruments within the historic building model to be manipulated within 3D space to demonstrate how the position measurements of stars were made in the 18th century. A description is given of current student and researchers activities concerning on-site recording and surveying and the virtual modelling of the buildings and landscape. This is followed by a design for a Virtual Reality Immersive Model of Armagh Observatory use game engine and virtual learning platforms and concepts.

Current Status of VO Compliant Data Service in Japanese Virtual Observatory

NASA Astrophysics Data System (ADS)

Shirasaki, Y.; Komiya, Y.; Ohishi, M.; Mizumoto, Y.; Ishihara, Y.; Tsutsumi, J.; Hiyama, T.; Nakamoto, H.; Sakamoto, M.

2012-09-01

In these years, standards to build a Virtual Observatory (VO) data service have been established with the efforts in the International Virtual Observatory Alliance (IVOA). We applied these newly established standards (SSAP, TAP) to our VO service toolkit which was developed to implement earlier VO standards SIAP and (deprecated) SkyNode. The toolkit can be easily installed and provides a GUI interface to construct and manage VO service. In this paper, we describes the architecture of our toolkit and how it is used to start hosting VO service.

A Virtual Observatory Approach to Planetary Data for Vesta and Ceres

NASA Astrophysics Data System (ADS)

Giardino, M.; Fonte, S.; Politi, R.; Ivanovski, S.; Longobardo, A.; Capria, M. T.; Erard, S.; De Sanctis, M. C.

2018-04-01

A virtual observatory service for DAWN/VIR spectral dataset is presented, based upon the IVOA standards adapted to the planetary field. Advantages of such an approach will be discussed, especially concerning interoperability and availability.

Interactive 3D visualization for theoretical virtual observatories

NASA Astrophysics Data System (ADS)

Dykes, T.; Hassan, A.; Gheller, C.; Croton, D.; Krokos, M.

2018-06-01

Virtual observatories (VOs) are online hubs of scientific knowledge. They encompass a collection of platforms dedicated to the storage and dissemination of astronomical data, from simple data archives to e-research platforms offering advanced tools for data exploration and analysis. Whilst the more mature platforms within VOs primarily serve the observational community, there are also services fulfilling a similar role for theoretical data. Scientific visualization can be an effective tool for analysis and exploration of data sets made accessible through web platforms for theoretical data, which often contain spatial dimensions and properties inherently suitable for visualization via e.g. mock imaging in 2D or volume rendering in 3D. We analyse the current state of 3D visualization for big theoretical astronomical data sets through scientific web portals and virtual observatory services. We discuss some of the challenges for interactive 3D visualization and how it can augment the workflow of users in a virtual observatory context. Finally we showcase a lightweight client-server visualization tool for particle-based data sets, allowing quantitative visualization via data filtering, highlighting two example use cases within the Theoretical Astrophysical Observatory.

The Role in the Virtual Astronomical Observatory in the Era of Massive Data Sets

NASA Technical Reports Server (NTRS)

Berriman, G. Bruce; Hanisch, Robert J.; Lazio, T. Joseph W.

2012-01-01

The Virtual Observatory (VO) is realizing global electronic integration of astronomy data. One of the long-term goals of the U.S. VO project, the Virtual Astronomical Observatory (VAO), is development of services and protocols that respond to the growing size and complexity of astronomy data sets. This paper describes how VAO staff are active in such development efforts, especially in innovative strategies and techniques that recognize the limited operating budgets likely available to astronomers even as demand increases. The project has a program of professional outreach whereby new services and protocols are evaluated.

The role in the Virtual Astronomical Observatory in the era of massive data sets

NASA Astrophysics Data System (ADS)

Berriman, G. Bruce; Hanisch, Robert J.; Lazio, T. Joseph W.

2012-09-01

The Virtual Observatory (VO) is realizing global electronic integration of astronomy data. One of the long-term goals of the U.S. VO project, the Virtual Astronomical Observatory (VAO), is development of services and protocols that respond to the growing size and complexity of astronomy data sets. This paper describes how VAO staff are active in such development efforts, especially in innovative strategies and techniques that recognize the limited operating budgets likely available to astronomers even as demand increases. The project has a program of professional outreach whereby new services and protocols are evaluated.

Providing comprehensive and consistent access to astronomical observatory archive data: the NASA archive model

NASA Astrophysics Data System (ADS)

McGlynn, Thomas; Fabbiano, Giuseppina; Accomazzi, Alberto; Smale, Alan; White, Richard L.; Donaldson, Thomas; Aloisi, Alessandra; Dower, Theresa; Mazzerella, Joseph M.; Ebert, Rick; Pevunova, Olga; Imel, David; Berriman, Graham B.; Teplitz, Harry I.; Groom, Steve L.; Desai, Vandana R.; Landry, Walter

2016-07-01

Since the turn of the millennium a constant concern of astronomical archives have begun providing data to the public through standardized protocols unifying data from disparate physical sources and wavebands across the electromagnetic spectrum into an astronomical virtual observatory (VO). In October 2014, NASA began support for the NASA Astronomical Virtual Observatories (NAVO) program to coordinate the efforts of NASA astronomy archives in providing data to users through implementation of protocols agreed within the International Virtual Observatory Alliance (IVOA). A major goal of the NAVO collaboration has been to step back from a piecemeal implementation of IVOA standards and define what the appropriate presence for the US and NASA astronomy archives in the VO should be. This includes evaluating what optional capabilities in the standards need to be supported, the specific versions of standards that should be used, and returning feedback to the IVOA, to support modifications as needed. We discuss a standard archive model developed by the NAVO for data archive presence in the virtual observatory built upon a consistent framework of standards defined by the IVOA. Our standard model provides for discovery of resources through the VO registries, access to observation and object data, downloads of image and spectral data and general access to archival datasets. It defines specific protocol versions, minimum capabilities, and all dependencies. The model will evolve as the capabilities of the virtual observatory and needs of the community change.

Providing Comprehensive and Consistent Access to Astronomical Observatory Archive Data: The NASA Archive Model

NASA Technical Reports Server (NTRS)

McGlynn, Thomas; Guiseppina, Fabbiano A; Accomazzi, Alberto; Smale, Alan; White, Richard L.; Donaldson, Thomas; Aloisi, Alessandra; Dower, Theresa; Mazzerella, Joseph M.; Ebert, Rick;

The Virtual Astronomical Observatory: Re-engineering access to astronomical data

NASA Astrophysics Data System (ADS)

Hanisch, R. J.; Berriman, G. B.; Lazio, T. J. W.; Emery Bunn, S.; Evans, J.; McGlynn, T. A.; Plante, R.

2015-06-01

The US Virtual Astronomical Observatory was a software infrastructure and development project designed both to begin the establishment of an operational Virtual Observatory (VO) and to provide the US coordination with the international VO effort. The concept of the VO is to provide the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. This paper describes the origins of the VAO, including the predecessor efforts within the US National Virtual Observatory, and summarizes its main accomplishments. These accomplishments include the development of both scripting toolkits that allow scientists to incorporate VO data directly into their reduction and analysis environments and high-level science applications for data discovery, integration, analysis, and catalog cross-comparison. Working with the international community, and based on the experience from the software development, the VAO was a major contributor to international standards within the International Virtual Observatory Alliance. The VAO also demonstrated how an operational virtual observatory could be deployed, providing a robust operational environment in which VO services worldwide were routinely checked for aliveness and compliance with international standards. Finally, the VAO engaged in community outreach, developing a comprehensive web site with on-line tutorials, announcements, links to both US and internationally developed tools and services, and exhibits and hands-on training at annual meetings of the American Astronomical Society and through summer schools and community days. All digital products of the VAO Project, including software, documentation, and tutorials, are stored in a repository for community access. The enduring legacy of the VAO is an increasing expectation that new telescopes and facilities incorporate VO capabilities during the design of their data management systems.

DETECTION OF FAST-MOVING WAVES PROPAGATING OUTWARD ALONG SUNSPOTS’ RADIAL DIRECTION IN THE PHOTOSPHERE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Junwei; Chen, Ruizhu; Hartlep, Thomas

2015-08-10

Helioseismic and magnetohydrodynamic waves are abundant in and above sunspots. Through cross-correlating oscillation signals in the photosphere observed by the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, we reconstruct how waves propagate away from virtual wave sources located inside a sunspot. In addition to the usual helioseismic wave, a fast-moving wave is detected traveling along the sunspot’s radial direction from the umbra to about 15 Mm beyond the sunspot boundary. The wave has a frequency range of 2.5–4.0 mHz with a phase velocity of 45.3 km s{sup −1}, substantially faster than the typical speeds of Alfvén and magnetoacoustic waves in themore » photosphere. The observed phenomenon is consistent with a scenario of that a magnetoacoustic wave is excited at approximately 5 Mm beneath the sunspot. Its wavefront travels to and sweeps across the photosphere with a speed higher than the local magnetoacoustic speed. The fast-moving wave, if truly excited beneath the sunspot’s surface, will help open a new window for studying the internal structure and dynamics of sunspots.« less

MASER: Measuring, Analysing, Simulating low frequency Radio Emissions.

NASA Astrophysics Data System (ADS)

Cecconi, B.; Le Sidaner, P.; Savalle, R.; Bonnin, X.; Zarka, P. M.; Louis, C.; Coffre, A.; Lamy, L.; Denis, L.; Griessmeier, J. M.; Faden, J.; Piker, C.; André, N.; Genot, V. N.; Erard, S.; King, T. A.; Mafi, J. N.; Sharlow, M.; Sky, J.; Demleitner, M.

2017-12-01

The MASER (Measuring, Analysing and Simulating Radio Emissions) project provides a comprehensive infrastructure dedicated to low frequency radio emissions (typically < 50 to 100 MHz). The four main radio sources observed in this frequency are the Earth, the Sun, Jupiter and Saturn. They are observed either from ground (down to 10 MHz) or from space. Ground observatories are more sensitive than space observatories and capture high resolution data streams (up to a few TB per day for modern instruments). Conversely, space-borne instruments can observe below the ionospheric cut-off (10 MHz) and can be placed closer to the studied object. Several tools have been developed in the last decade for sharing space physcis data. Data visualization tools developed by The CDPP (http://cdpp.eu, Centre de Données de la Physique des Plasmas, in Toulouse, France) and the University of Iowa (Autoplot, http://autoplot.org) are available to display and analyse space physics time series and spectrograms. A planetary radio emission simulation software is developed in LESIA (ExPRES: Exoplanetary and Planetary Radio Emission Simulator). The VESPA (Virtual European Solar and Planetary Access) provides a search interface that allows to discover data of interest for scientific users, and is based on IVOA standards (astronomical International Virtual Observatory Alliance). The University of Iowa also develops Das2server that allows to distribute data with adjustable temporal resolution. MASER is making use of all these tools and standards to distribute datasets from space and ground radio instruments available from the Observatoire de Paris, the Station de Radioastronomie de Nançay and the CDPP deep archive. These datasets include Cassini/RPWS, STEREO/Waves, WIND/Waves, Ulysses/URAP, ISEE3/SBH, Voyager/PRA, Nançay Decameter Array (Routine, NewRoutine, JunoN), RadioJove archive, swedish Viking mission, Interball/POLRAD... MASER also includes a Python software library for reading raw data.

Armenian Virtual Observatory: Services and Data Sharing

NASA Astrophysics Data System (ADS)

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

2016-06-01

The main aim of this article is to introduce the data management and services of the Armenian Virtual Observatory (ArVO), which consists of user friendly data management mechanisms, a new and productive cross-correlation service, and data sharing API based on international standards and protocols.

UkrVO astronomical WEB services

NASA Astrophysics Data System (ADS)

Mazhaev, A.

2017-02-01

Ukraine Virtual Observatory (UkrVO) has been a member of the International Virtual Observatory Alliance (IVOA) since 2011. The virtual observatory (VO) is not a magic solution to all problems of data storing and processing, but it provides certain standards for building infrastructure of astronomical data center. The astronomical databases help data mining and offer to users an easy access to observation metadata, images within celestial sphere and results of image processing. The astronomical web services (AWS) of UkrVO give to users handy tools for data selection from large astronomical catalogues for a relatively small region of interest in the sky. Examples of the AWS usage are showed.

Exploring the Digital Universe with Europe's Astrophysical Virtual Observatory

NASA Astrophysics Data System (ADS)

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 need for virtual observatories has also been recognised by other astronomical communities. The National Science Foundation in the USA has awarded $10 million (EUR 11.4 m) for a National Virtual Observatory (NVO). The AVO project team has formed a close alliance with the NVO and both teams have representatives on each other's committees. It is clear to the NVO and AVO communities that there are no intrinsic boundaries to the virtual observatory concept and that all astronomers should be working towards a truly global virtual observatory that will enable new science to be carried out on the wealth of astronomical data held in the growing number of first-class international astronomical archives. AVO involves six partner organisations led by the European Southern Observatory (ESO) in Munich. The other partner organisations are the European Space Agency (ESA), the United Kingdom's ASTROGRID consortium, the CNRS-supported Centre de Données Astronomiques de Strasbourg (CDS) at the University Louis Pasteur in Strasbourg, the CNRS-supported TERAPIX astronomical data centre at the Institut d'Astrophysique in Paris and the Jodrell Bank Observatory at the University of Manchester. Note for editors A 13-minute background video (broadcast PAL) is available from ESO PR and the Hubble European Space Agency Information Centre (addresses below). It will also be transmitted via satellite on Wednesday 12 December 2001 from 12:00 to 12:15 CET on the ESA TV Service: http://television.esa.int

The Gran Telescopio Canarias and Calar Alto Virtual Observatory Compliant Archives

NASA Astrophysics Data System (ADS)

Alacid, J. M.; Solano, E.; Jiménez-Esteban, F. M.; Velasco, A.

2014-05-01

The Gran Telescopio Canarias and Calar Alto archives are the result of the collaboration agreements between the Centro de Astrobiología and two entities: GRANTECAN S.A. and the Centro Astronómico Hispano Alemán (CAHA). The archives have been developed in the framework of the Spanish Virtual Observatory and are maintained by the Data Archive Unit at Centro de Astrobiología. The archives contain both raw and science ready data and have been designed in compliance with the standards defined by the International Virtual Observatory Alliance, which guarantees a high level of data accessibility and handling. In this paper we describe the main characteristics and functionalities of both archives.

The Gran Telescopio Canarias and Calar Alto Virtual Observatory compliant archives

NASA Astrophysics Data System (ADS)

Solano, Enrique; Gutiérrez, Raúl; Alacid, José Manuel; Jiménez-Esteban, Francisco; Velasco Trasmonte, Almudena

2012-09-01

The Gran Telescopio Canarias (GTC) and Calar Alto archives are the result of the collaboration agreements between the Centro de Astrobiología (CAB, INTA-CSIC)) and two entities: GRANTECAN S.A. and the Centro Astronómico Hispano Alemán (CAHA). The archives have been developed in the framework of the Spanish Virtual Observatory and are maintained by the Data Archive Unit at CAB. The archives contain both raw and science ready data and have been designed in compliance with the standards defined by the International Virtual Observatory Alliance (IVOA) which guarantees a high level of data accessibility and handling. In this paper we describe the main characteristics and functionalities of both archives.

Handling knowledge via Concept Maps: a space weather use case

NASA Astrophysics Data System (ADS)

Messerotti, Mauro; Fox, Peter

Concept Maps (Cmaps) are powerful means for knowledge coding in graphical form. As flexible software tools exist to manipulate the knowledge embedded in Cmaps in machine-readable form, such complex entities are suitable candidates not only for the representation of ontologies and semantics in Virtual Observatory (VO) architectures, but also for knowledge handling and knowledge discovery. In this work, we present a use case relevant to space weather applications and we elaborate on its possible implementation and adavanced use in Semantic Virtual Observatories dedicated to Sun-Earth Connections. This analysis was carried out in the framework of the Electronic Geophysical Year (eGY) and represents an achievement synergized by the eGY Virtual Observatories Working Group.

Toward a Virtual Solar Observatory: Starting Before the Petabytes Fall

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Fisher, Richard R. (Technical Monitor)

2002-01-01

NASA is currently engaged in the study phase of a modest effort to establish a Virtual Solar Observatory (VSO). The VSO would serve ground- and space-based solar physics data sets from a distributed network of archives through a small number of interfaces to the scientific community. The basis of this approach, as of all planned virtual observatories, is the translation of metadata from the various sources via source-specific dictionaries so the user will not have to distinguish among keyword usages. A single Web interface should give access to all the distributed data. We present the current status of the VSO, its initial scope, and its relation to the European EGSO effort.

The Virtual Solar Observatory: Still a Small Box

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Bogart, R. S.; Davey, A. R.; Dimitoglou, G.; Hill, F.; Hourcle, J. A.; Martens, P. C.; Surez-Sola, I.; Tian, K. Q.; Wampler, S.

2005-01-01

Two and a half years after a design study began, and a year and a half after development commenced, version 1.0 of the Virtual Solar Observatory (VSO) was released at the 2004 Fall AGU meeting. Although internal elements of the VSO have changed, the basic design has remained the same, reflecting the team's belief in the importance of a simple, robust mechanism for registering data provider holdings, initiating queries at the appropriate provider sites, aggregating the responses, allowing the user to iterate before making a final selection, and enabling the delivery of data directly from the providers. In order to make the VSO transparent, lightweight, and portable, the developers employed XML for the registry, SOAP for communication between a VSO instance and data services, and HTML for the graphic user interface (GUI's). We discuss the internal data model, the API, and user responses to various trial GUI's as typical design issues for any virtual observatory. We also discuss the role of the "small box" of data search, identification, and delivery services provided by the VSO in the larger, Sun-Solar System Connection virtual observatory (VxO) scheme.

The Virtual Observatory as Critical Scientific Cyber Infrastructure.

NASA Astrophysics Data System (ADS)

Fox, P.

2006-12-01

Virtual Observatories can provide access to vast stores of scientific data: observations and models as well as services to analyze, visualize and assimilate multiple data sources. As these electronic resource become widely used, there is potential to improve the efficiency, interoperability, collaborative potential, and impact of a wide range of interdisciplinary scientific research. In addition, we know that as the diversity of collaborative science and volume of accompanying data and data generators/consumers grows so do the challenges. In order for Virtual Observatories to realize their potential and become indispensible infrastructure, social, political and technical challenges need to be addressed concerning (at least) roles and responsibilities, data and services policies, representations and interoperability of services, data search, access, and usability. In this presentation, we discuss several concepts and instances of the Virtual Observatory and related projects that may, and may not, be meeting the abovementioned challanges. We also argue that science driven needs and architecture development are critical in the development of sustainable (and thus agile) cyberinfrastructure. Finally we some present or emerging candidate technologies and organizational constructs that will need to be pursued.

AstroGrid: the UK's Virtual Observatory Initiative

NASA Astrophysics Data System (ADS)

Mann, Robert G.; Astrogrid Consortium; Lawrence, Andy; Davenhall, Clive; Mann, Bob; McMahon, Richard; Irwin, Mike; Walton, Nic; Rixon, Guy; Watson, Mike; Osborne, Julian; Page, Clive; Allan, Peter; Giaretta, David; Perry, Chris; Pike, Dave; Sherman, John; Murtagh, Fionn; Harra, Louise; Bentley, Bob; Mason, Keith; Garrington, Simon

AstroGrid is the UK's Virtual Observatory (VO) initiative. It brings together the principal astronomical data centres in the UK, and has been funded to the tune of ˜pounds 5M over the next three years, via PPARC, as part of the UK e--science programme. Its twin goals are the provision of the infrastructure and tools for the federation and exploitation of large astronomical (X-ray to radio), solar and space plasma physics datasets, and the delivery of federations of current datasets for its user communities to exploit using those tools. Whilst AstroGrid's work will be centred on existing and future (e.g. VISTA) UK datasets, it will seek solutions to generic VO problems and will contribute to the developing international virtual observatory framework: AstroGrid is a member of the EU-funded Astrophysical Virtual Observatory project, has close links to a second EU Grid initiative, the European Grid of Solar Observations (EGSO), and will seek an active role in the development of the common standards on which the international virtual observatory will rely. In this paper we shall primarily describe the concrete plans for AstroGrid's one-year Phase A study, which will centre on: (i) the definition of detailed science requirements through community consultation; (ii) the undertaking of a ``functionality market survey" to test the utility of existing technologies for the VO; and (iii) a pilot programme of database federations, each addressing different aspects of the general database federation problem. Further information on AstroGrid can be found at AstroGrid .

Crosswalking near-Earth and space physics ontologies in SPASE and ESPAS

NASA Astrophysics Data System (ADS)

Galkin, I. A.; Fung, S. F.; Benson, R. F.; Heynderickx, D.; Ritschel, B.; King, T. A.; Roberts, D. A.; Hapgood, M. A.; Belehaki, A.

2015-12-01

In order to support scientific discoveries in Heliophysics (HP), with modern data systems, the HP Data Centers actively pursue harmonization of available metadata that allows crossing boundaries between existing data models, conventions, and resource interfaces. The discoverability of HP observations is improved when associated metadata describes their physical content in agreed terms as a part of the resource registration. One of the great challenges of enabling such content-targeted data search capability is the harmonization of domain ontology across data providers. Ontologies are the cornerstones of the content-aware data systems: they define an agreed vocabulary of keywords that capture the essence of domain-specific concepts and their relationships. With the introduction of the Virtual Wave Observatory (VWO), as part of NASA's Virtual System Observatory in 2008, the task of formulating the HP ontology became yet more complicated. Definitions of the wave domain concepts required several layers of specifications that described the generation, propagation, and interaction of the waves with the underlying medium in addition to the observation itself. Simple keyword lists could not provide a sufficiently information-rich description, given the complexity of the wave domain, and the development of a more powerful schema was required. The ontology research at the VWO eventually resulted in a suitable multi-hierarchical design that found its first implementation in 2015 at one of the European space physics data repositories, the near-Earth Space Data Infrastructure for e-Science (ESPAS). Similar to many other European geoscience projects, ESPAS is based on the ISO 19156 Observation and Measurements standard. In cooperation with the NASA VWO, the ESPAS project has deployed a space physics ontology design for all data registration purposes. The VWO science team is now uniquely positioned to establish a crosswalk between the ESPAS ontology based on ISO 19156 and the VWO ontology based on the SPASE data model. The crosswalk both maps the individual vocabulary terms and accommodates the underlying differences in the structural model elements that are part of both standards. We will review practical questions of harmonizing SPASE and ISO solutions specific to the HP domain ontology.

Still Virtual After All These Years: Recent Developments in the Virtual Solar Observatory

NASA Astrophysics Data System (ADS)

Gurman, J. B.; Bogart, R. S.; Davey, A. R.; Hill, F.; Martens, P. C.; Zarro, D. M.; Team, T. v.

2008-05-01

While continuing to add access to data from new missions, including Hinode and STEREO, the Virtual Solar Observatory is also being enhanced as a research tool by the addition of new features such as the unified representation of catalogs and event lists (to allow joined searches in two or more catalogs) and workable representation and manipulation of large numbers of search results (as are expected from the Solar Dynamics Observatory database). Working with our RHESSI colleagues, we have also been able to improve the performance of IDL-callable vso_search and vso_get functions, to the point that use of those routines is a practical alternative to reproducing large subsets of mission data on one's own LAN.

Still Virtual After All These Years: Recent Developments in the Virtual Solar Observatory

NASA Technical Reports Server (NTRS)

Gurman, Joseph B.; Bogart; Davey; Hill; Masters; Zarro

2008-01-01

While continuing to add access to data from new missions, including Hinode and STEREO, the Virtual Solar Observatory is also being enhanced as a research tool by the addition of new features such as the unified representation of catalogs and event lists (to allow joined searches in two or more catalogs) and workable representation and manipulation of large numbers of search results (as are expected from the Solar Dynamics Observatory database). Working with our RHESSI colleagues, we have also been able to improve the performance of IDL-callable vso_search and vso_get functions, to the point that use of those routines is a practical alternative to reproducing large subsets of mission data on one's own LAN.

Exploring the Digital Universe with Europe's Astrophysical Virtual Observatory

NASA Astrophysics Data System (ADS)

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 digitally reconstructed in the databanks! The richness and complexity of data and information available to the astronomers is overwhelming. This has created a major problem as to how astronomers can manage, distribute and analyse this great wealth of data . The Astrophysical Virtual Observatory (AVO) will allow astronomers to overcome the challenges and enable them to "put the Universe online". AVO is supported by the European Commission The 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 European Commission awarded a contract valued at 4 million Euro for the AVO project , starting 15 November 2001. 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, be both costly and take far too long. Towards a Global Virtual Observatory The need for virtual observatories has also been recognised by other astronomical communities. The National Science Foundation in the USA has awarded 10 million Dollar (approx. 11.4 million Euro) for a National Virtual Observatory (NVO). The AVO project team has formed a close alliance with the NVO and both teams have representatives on their respective committees. It is clear to the NVO and AVO communities that there are no intrinsic boundaries to the virtual observatory concept and that all astronomers should be working towards a truly global virtual observatory that will enable new science to be carried out on the wealth of astronomical data held in the growing number of first class international astronomical archives. The AVO involves six partner organisations led by the European Southern Observatory (ESO) in Munich (Germany). The other partner organisations are the European Space Agency (ESA) , the United Kingdom's ASTROGRID consortium, the CNRS-supported Centre de Données Astronomiques de Strasbourg (CDS) at the University Louis Pasteur in Strasbourg (France), the CNRS-supported TERAPIX astronomical data centre at the Institut d'Astrophysique in Paris and the Jodrell Bank Observatory of the Victoria University of Manchester (UK). Note [1]: This is a joint Press Release issued by the European Southern Observatory (ESO), the Hubble European Space Agency Information Centre, ASTROGRID, CDS, TERAPIX/CNRS and the University of Manchester. A 13 minute background video (broadcast PAL) is available from ESO PR and the Hubble European Space Agency Information Centre (addresses below). This will also be transmitted via satellite Wednesday 12 December 2001 from 12:00 to 12:15 CET on "ESA TV Service", cf. http://television.esa.int. An international conference, "Toward an International Virtual Observatory" will take place at ESO (Garching, Germany) on June 10 - 14, 2002. Contacts AVO Contacts Peter Quinn European Southern Observatory Garching, Germany Tel.: +4989-3200-6509 email: pjq@eso.org Piero Benvenuti Space Telescope-European Coordinating Facility Garching, Germany Tel.: +49-89-3200-6290 email: pbenvenu@eso.org Andy Lawrence (on behalf of The ASTROGRID Consortium) Institute for Astronomy University of Edinburgh United Kingdom Tel.: +44-131-668-8346/56 email: al@roe.ac.uk Francoise Genova Centre de Données Astronomiques de Strasbourg (CDS) France Tel.: +33-390-24-24-76 email: genova@astro.u-strasbg.fr Yannick Mellier CNRS, Delegation Paris A (CNRSDR01-Terapix)/IAP/INSU France Tel.: +33-1-44-32-81-40 email: mellier@iap.fr Phil Diamond University of Manchester/Jodrell Bank Observatory United Kingdom Tel.: +44-147-757-2625 email: pdiamond@jb.man.ac.uk PR Contacts Richard West European Southern Observatory Garching, Germany Tel.: +49-89-3200-6276 email: rwest@eso.org Lars Lindberg Christensen Hubble European Space Agency Information Centre Garching, Germany Tel.: +49-89-3200-6306 or +49-173-38-72-621 email: lars@eso.org Ray Footman The ASTROGRID Consortium/University of Edinburgh United Kingdom Tel.: +44-131-650-2249 email: r.footman@ed.ac.uk Philippe Chauvin Terapix/CDS CNRS, Delegation Paris A, IAP/INSU France Tel.: +33 1 44 96 43 36 email: philippe.chauvin@cnrs-dir.fr Agnes Villanueva University of Strasbourg France Tel.: +33 3 90 24 11 35 email: agnes.villanueva@adm-ulp.u-strasbg.fr Ian Morison University of Manchester/Jodrell Bank Observatory United Kingdom Tel.: +44 1477 572610 email: im@jb.man.ac.uk Appendix: Introduction to Europe's Astrophysical Virtual Observatory (AVO) The Digital Data Revolution Over the past thirty years, astronomers have moved from photographic and analogue techniques towards the use of high-speed, digital instruments connected to specialised telescopes to study the Universe. Whether these instruments are onboard spacecraft or located at terrestrial observatories, the data they produce are stored digitally on computer systems for later analysis. Two Challenges This data revolution has created two challenges for astronomers. Firstly, as the capability of digital detector systems has advanced, the volume of digital data that astronomical facilities are producing has expanded greatly. The rate of growth of the volume of stored data far exceeds the rate of increase in the performance of computer systems or storage devices. Secondly, astronomers have realised that many important insights into the deepest secrets in the Universe can come from combining information obtained at many wavelengths into a consistent and comprehensive physical picture . However, because the datasets from different parts of the spectrum come from different observatories using different instruments, the data are not easily combined. To unite data from different observatories, bridges must be built between digital archives to allow them to share data and "interoperate" - an important and challenging task. The Human Factor These challenges are not only technological. Our brains are not equipped to for instance analyse simultaneously the millions and millions of images available. Astronomers must adapt and learn to deal with such diverse and extensive sets of data. The "digital sky" has the potential to become a vital tool with novel and fascinating capabilities that are essential for astronomers to make progress in their understanding of the Cosmos. But astronomers must be able to find the relevant information quickly and efficiently. Currently the data needed by a particular research program may well be stored in the archives already, but the tools and methods have not yet been developed to extract the relevant information from the flood of images available. A new way of thinking, a new frame of mind and a new approach are needed. The Astrophysical Virtual Observatory The Astrophysical Virtual Observatory (AVO) will allow astronomers to overcome the challenges and extract data from the digital sky, thus "putting the Universe online" . Like a search engine helps us to find information on the Internet, astronomers need sophisticated "search engines" as well as other tools to find and interpret the information. "We're drowning in information and starving for knowledge", a Yale University librarian once said. Or to paraphrase a popular series on TV: "The information is out there, but you have to find it!" Using the latest in computer technology, data storage and analysis techniques, AVO will maximise the potential for new scientific insights from the stored data by making them available in a readily accessible and seamlessly unified form to professional researchers, amateur astronomers and students. Users of AVO will have immense multi-wavelength vistas of the digital Universe at their fingertips and the potential to make breathtaking new discoveries. Virtual observatories signal a new era, where data collected by a multitude of sophisticated telescopes can be used globally and repeatedly to achieve substantial progress in the quest for knowledge. The AVO project, funded by the European Commission, is a three-year study of the design and implementation of a virtual observatory for European astronomy. A virtual observatory is a collection of connected data archives and software tools that utilise the Internet to form a scientific research environment in which new multi-wavelength astronomical research programs can be conducted. In much the same way as a real observatory consists of telescopes, each with a collection of unique astronomical instruments, the virtual observatory consists of a collection of data centres each with unique collections of astronomical data, software systems and processing capabilities. The programme will implement and test a prototype virtual observatory , focussing on the key areas of scientific requirements, interoperability and new technologies such as the GRID, needed to link powerful computers to the newly formed large data repositories. The GRID and the Future of the Internet The technical problems astronomers have to solve are similar to those being worked on by particle physicists, by biologists, and by commercial companies who want to search and fill customer databases across the world. The emerging idea is that of the GRID where computers collaborate across the Internet. The World Wide Web made words and pictures available to anybody at the click of a mouse. The GRID will do the same for data, and for computer processing power. Anybody can have the power of a supercomputer sitting on their desktop. The Astrophysical Virtual Observatory, and GRID projects like the ASTROGRID project in the United Kingdom (funding 5 million UK Pounds or 8 million Euro), are closely linked to these developments.

Environment Study of AGNs at z = 0.3 to 3.0 Using the Japanese Virtual Observatory

NASA Astrophysics Data System (ADS)

Shirasaki, Y.; Ohishi, M.; Mizumoto, Y.; Takata, T.; Tanaka, M.; Yasuda, N.

2010-12-01

We present a science use case of Virtual Observatory, which was achieved to examine an environment of AGN up to redshift of 3.0. We used the Japanese Virtual Observatory (JVO) to obtain Subaru Suprime-Cam images around known AGNs. According to the hierarchical galaxy formation model, AGNs are expected to be found in an environment of higher galaxy density than that of typical galaxies. The current observations, however, indicate that AGNs do not reside in a particularly high density environment. We investigated ˜1000 AGNs, which is about ten times larger samples than the other studies covering the redshifts larger than 0.6. We successfully found significant excess of galaxies around AGNs at redshifts of 0.3 to 1.8. If this work was done in a classical manner, that is, raw data were retrieved from the archive through a form-based web interface in an interactive way, and the data were reduced on a low performance computer, it might take several years to finish it. Since the Virtual Observatory system is accessible through a standard interface, it is easy to query and retrieve data in an automatic way. We constructed a pipeline for retrieving the data and calculating the galaxy number density around a given coordinate. This procedure was executed in parallel on ˜10 quad core PCs, and it took only one day for obtaining the final result. Our result implies that the Virtual Observatory can be a powerful tool to do an astronomical research based on large amount of data.

The Virtual Watershed Observatory: Cyberinfrastructure for Model-Data Integration and Access

NASA Astrophysics Data System (ADS)

Duffy, C.; Leonard, L. N.; Giles, L.; Bhatt, G.; Yu, X.

2011-12-01

The Virtual Watershed Observatory (VWO) is a concept where scientists, water managers, educators and the general public can create a virtual observatory from integrated hydrologic model results, national databases and historical or real-time observations via web services. In this paper, we propose a prototype for automated and virtualized web services software using national data products for climate reanalysis, soils, geology, terrain and land cover. The VWO has the broad purpose of making accessible water resource simulations, real-time data assimilation, calibration and archival at the scale of HUC 12 watersheds (Hydrologic Unit Code) anywhere in the continental US. Our prototype for model-data integration focuses on creating tools for fast data storage from selected national databases, as well as the computational resources necessary for a dynamic, distributed watershed simulation. The paper will describe cyberinfrastructure tools and workflow that attempts to resolve the problem of model-data accessibility and scalability such that individuals, research teams, managers and educators can create a WVO in a desired context. Examples are given for the NSF-funded Shale Hills Critical Zone Observatory and the European Critical Zone Observatories within the SoilTrEC project. In the future implementation of WVO services will benefit from the development of a cloud cyber infrastructure as the prototype evolves to data and model intensive computation for continental scale water resource predictions.

Distributing Variable Star Data to the Virtual Observatory

NASA Astrophysics Data System (ADS)

Kinne, Richard C.; Templeton, M. R.; Henden, A. A.; Zografou, P.; Harbo, P.; Evans, J.; Rots, A. H.; LAZIO, J.

2013-01-01

Effective distribution of data is a core element of effective astronomy today. The AAVSO is the home of several different unique databases. The AAVSO International Database (AID) contains over a century of photometric and time-series data on thousands of individual variable stars comprising over 22 million observations. The AAVSO Photometric All-Sky Survey (APASS) is a new photometric catalog containing calibrated photometry in Johnson B, V and Sloan g', r' and i' filters for stars with magnitudes of 10 < V < 17. The AAVSO is partnering with researchers and technologists at the Virtual Astronomical Observatory (VAO) to solve the data distribution problem for these datasets by making them available via various VO tools. We give specific examples of how these data can be accessed through Virtual Observatory (VO) toolsets and utilized for astronomical research.

Press Meeting 20 January 2003: First Light for Europe's Virtual Observatory

NASA Astrophysics Data System (ADS)

2002-12-01

Imagine you are an astronomer with instant, fingertip access to all existing observations of a given object and the opportunity to sift through them at will. In just a few moments, you can have information on all kinds about objects out of catalogues all over the world, including observations taken at different times. Over the next two years this scenario will become reality as Europe's Astrophysical Virtual Observatory (AVO) develops. Established only a year ago (cf. ESO PR 26/01), the AVO already offers astronomers a unique, prototype research tool that will lead the way to many outstanding new discoveries. Journalists are invited to a live demonstration of the capabilities of this exciting new initiative in astronomy. The demonstration will take place at the Jodrell Bank Observatory in Manchester, in the United Kingdom, on 20 January 2003, starting at 11:00. Sophisticated AVO tools will help scientists find the most distant supernovae - objects that reveal the cosmological makeup of our Universe. The tools are also helping astronomers measure the rate of birth of stars in extremely red and distant galaxies. Journalists will also have the opportunity to discuss the project with leading astronomers from across Europe. The new AVO website has been launched today, explaining the progress being made in this European Commission-funded project: URL: http://www.euro-vo.org/ To register your intention to attend the AVO First Light Demonstration, please provide your name and affiliation by January 13, 2003, to: Ian Morison, Jodrell Bank Observatory (full contact details below). Information on getting to the event is included on the webpage above. Programme for the AVO First Light Demonstration 11:00 Welcome, Phil Diamond (University of Manchester/Jodrell Bank Observatory) 11:05 Short introduction to Virtual Observatories, Piero Benvenuti (ESA/ST-ECF) 11:15 Q&A 11:20 Short introduction to the Astrophysical Virtual Observatory, Peter Quinn (ESO) 11:30 Q&A 11:35 Screening of Video News Release 11:40 Demonstration of the AVO prototype, Nicholas Walton (University of Cambridge) 12:00 Q&A, including interview possibilities with the scientists 12:30-13:45 Buffet lunch, including individual hands-on demos 14:00 Science Demo (also open to interested journalists) For more information about Virtual Observatories and the AVO, see the website or the explanation below. Notes to editors The AVO involves several partner organisations led by the European Southern Observatory (ESO). The other partner organisations are the European Space Agency (ESA), AstroGrid (funded by PPARC as part of the UK's E-Science programme), the CNRS-supported Centre de Données Astronomiques de Strasbourg (CDS), the University Louis Pasteur in Strasbourg, France, the CNRS-supported TERAPIX astronomical data centre at the Institut d'Astrophysique in Paris, France, and the Jodrell Bank Observatory of the Victoria University of Manchester, United Kingdom. Note [1]: This is a joint Press Release issued by the European Southern Observatory (ESO), the Hubble European Space Agency Information Centre, AstroGrid, CDS, TERAPIX/CNRS and the University of Manchester. Science Contacts Peter J. Quinn European Southern Observatory (ESO) Garching, Germany Tel: +49-89-3200 -6509 email: pjq@eso.org Phil Diamond University of Manchester/Jodrell Bank Observatory United Kingdom Tel: +44-147-757-26-25 (0147 in the United Kingdom) email: pdiamond@jb.man.ac.uk Press contacts Ian Morison University of Manchester/Jodrell Bank Observatory United Kingdom Tel: +44-147-757-26-10 (0147 in the United Kingdom) E-mail: email: im@jb.man.ac.uk Lars Lindberg Christensen Hubble European Space Agency Information Centre Garching, Germany Tel: +49-89-3200-6306 (089 in Germany) Cellular (24 hr): +49-173-3872-621 (0173 in Germany) email: lars@eso.org Richard West (ESO EPR Dept.) ESO EPR Dept. Garching, Germany Phone: +49-89-3200-6276 email: rwest@eso.org Background information What is a Virtual Observatory? - A short introduction The Virtual Observatory is an international astronomical community-based initiative. It aims to allow global electronic access to the available astronomical data archives of space and ground-based observatories, sky survey databases. It also aims to enable data analysis techniques through a coordinating entity that will provide common standards, wide-network bandwidth, and state-of-the-art analysis tools. It is now possible to have powerful and expensive new observing facilities at wavelengths from the radio to the X-ray and gamma-ray regions. Together with advanced instrumentation techniques, a vast new array of astronomical data sets will soon be forthcoming at all wavelengths. These very large databases must be archived and made accessible in a systematic and uniform manner to realise the full potential of the new observing facilities. The Virtual Observatory aims to provide the framework for global access to the various data archives by facilitating the standardisation of archiving and data-mining protocols. The AVO will also take advantage of state-of-the-art advances in data-handling software in astronomy and in other fields. The Virtual Observatory initiative is currently aiming at a global collaboration of the astronomical communities in Europe, North and South America, Asia, and Australia under the auspices of the recently formed International Virtual Observatory Alliance. The Astrophysical Virtual Observatory - An Introduction The breathtaking capabilities and ultrahigh efficiency of new ground and space observatories have led to a 'data explosion' calling for innovative ways to process, explore, and exploit these data. Researchers must now turn to the GRID paradigm of distributed computing and resources to solve complex, front-line research problems. To implement this new IT paradigm, you have to join existing astronomical data centres and archives into an interoperating and single unit. This new astronomical data resource will form a Virtual Observatory (VO) so that astronomers can explore the digital Universe in the new archives across the entire spectrum. Similarly to how a real observatory consists of telescopes, each with a collection of unique astronomical instruments, the VO consists of a collection of data centres each with unique collections of astronomical data, software systems, and processing capabilities. The Astrophysical Virtual Observatory Project (AVO) will conduct a research and demonstration programme on the scientific requirements and technologies necessary to build a VO for European astronomy. The AVO has been jointly funded by the European Commission (under FP5 - Fifth Framework Programme) with six European organisations participating in a three year Phase-A work programme, valued at 5 million Euro. The partner organisations are the European Southern Observatory (ESO) in Munich, Germany, the European Space Agency (ESA), AstroGrid (funded by PPARC as part of the UK's E-Science programme), the CNRS-supported Centre de Données Astronomiques de Strasbourg (CDS), the University Louis Pasteur in Strasbourg, France, the CNRS-supported TERAPIX astronomical data centre at the Institut d'Astrophysique in Paris, France, and the Jodrell Bank Observatory of the Victoria University of Manchester, United Kingdom. The Phase A program will focus its effort in the following areas: * A detailed description of the science requirements for the AVO will be constructed, following the experience gained in a smaller-scale science demonstration program called ASTROVIRTEL (Accessing Astronomical Archives as Virtual Telescopes). * The difficult issue of data and archive interoperability will be addressed by new standards definitions for astronomical data and trial programmes of "joins" between specific target archives within the project team. * The necessary GRID and database technologies will be assessed and tested for use within a full AVO implementation. The AVO project is currently working in conjunction with other international VO efforts in the United States and Asia-Pacific region. This is part of an International Virtual Observatory Alliance to define essential new data standards so that the VO concept can have a global dimension. The AVO partners will join with all astronomical data centres in Europe to put forward an FP6 IST (Sixth Framework Programme - Information Society Technologies Programme) Integrated Project proposal to make a European VO fully operational by the end of 2007.

Lessons Learned during the Development and Operation of Virtual Observatory

NASA Astrophysics Data System (ADS)

Ohishi, M.; Shirasaki, Y.; Komiya, Y.; Mizumoto, Y.; Yasuda, N.; Tanaka, M.

2010-12-01

In the last a few years several Virtual Observatory (VO) projects have entered from the research and development phase to the operations phase. The VO projects include AstroGrid (UK), Virtual Astronomical Observatory (former National Virtual Observatory, USA), EURO-VO (EU), Japanese Virtual Observatory (Japan), and so on. This successful transition from the development phase to the operations phase owes primarily to the concerted action to develop standard interfaces among the VO projects in the world, that has been conducted in the International Virtual Observatory Alliance. The registry interface has been one of the most important key to share among the VO projects and data centers (data providers) with the observed data and the catalog data. Data access protocols and/or language (SIAP, SSAP, ADQL) and the common data format (VOTable) are other keys. Consequently we are able to find scientific papers so far published. However, we had faced some experience during the implementation process as follows:

The Planetary Virtual Observatory and Laboratory (PVOL) and its integration into the Virtual European Solar and Planetary Access (VESPA)

NASA Astrophysics Data System (ADS)

Hueso, R.; Juaristi, J.; Legarreta, J.; Sánchez-Lavega, A.; Rojas, J. F.; Erard, S.; Cecconi, B.; Le Sidaner, Pierre

2018-01-01

Since 2003 the Planetary Virtual Observatory and Laboratory (PVOL) has been storing and serving publicly through its web site a large database of amateur observations of the Giant Planets (Hueso et al., 2010a). These images are used for scientific research of the atmospheric dynamics and cloud structure on these planets and constitute a powerful resource to address time variable phenomena in their atmospheres. Advances over the last decade in observation techniques, and a wider recognition by professional astronomers of the quality of amateur observations, have resulted in the need to upgrade this database. We here present major advances in the PVOL database, which has evolved into a full virtual planetary observatory encompassing also observations of Mercury, Venus, Mars, the Moon and the Galilean satellites. Besides the new objects, the images can be tagged and the database allows simple and complex searches over the data. The new web service: PVOL2 is available online in http://pvol2.ehu.eus/.

Solar-Terrestrial Ontology Development

NASA Astrophysics Data System (ADS)

McGuinness, D.; Fox, P.; Middleton, D.; Garcia, J.; Cinquni, L.; West, P.; Darnell, J. A.; Benedict, J.

2005-12-01

The development of an interdisciplinary virtual observatory (the Virtual Solar-Terrestrial Observatory; VSTO) as a scalable environment for searching, integrating, and analyzing databases distributed over the Internet requires a higher level of semantic interoperability than here-to-fore required by most (if not all) distributed data systems or discipline specific virtual observatories. The formalization of semantics using ontologies and their encodings for the internet (e.g. OWL - the Web Ontology Language), as well as the use of accompanying tools, such as reasoning, inference and explanation, open up both a substantial leap in options for interoperability and in the need for formal development principles to guide ontology development and use within modern, multi-tiered network data environments. In this presentation, we outline the formal methodologies we utilize in the VSTO project, the currently developed use-cases, ontologies and their relation to existing ontologies (such as SWEET).

Jupiter cloud morphology and zonal winds from ground-based observations before and during Juno's first perijove

NASA Astrophysics Data System (ADS)

Hueso, R.; Sánchez-Lavega, A.; Iñurrigarro, P.; Rojas, J. F.; Pérez-Hoyos, S.; Mendikoa, I.; Gómez-Forrellad, J. M.; Go, C.; Peach, D.; Colas, F.; Vedovato, M.

2017-05-01

We analyze Jupiter observations between December 2015 and August 2016 in the 0.38-1.7 μm wavelength range from the PlanetCam instrument at the 2.2 m telescope at Calar Alto Observatory and in the optical range by amateur observers contributing to the Planetary Virtual Observatory Laboratory. Over this time Jupiter was in a quiescent state without notable disturbances. Analysis of ground-based images and Hubble Space Telescope observations in February 2016 allowed the retrieval of mean zonal winds from -74.5° to +73.2°. These winds did not change over 2016 or when compared with winds from previous years with the sole exception of intense zonal winds at the North Temperate Belt. We also present results concerning the major wave systems in the North Equatorial Belt and in the upper polar hazes visible in methane absorption bands, a description of the planet's overall cloud morphology and observations of Jupiter hours before Juno's orbit insertion.

Virtual Astronomy: The Legacy of the Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Hanisch, Robert J.; Berriman, G. B.; Lazio, J.; Szalay, A. S.; Fabbiano, G.; Plante, R. L.; McGlynn, T. A.; Evans, J.; Emery Bunn, S.; Claro, M.; VAO Project Team

2014-01-01

Over the past ten years, the Virtual Astronomical Observatory (VAO, http://usvao.org) and its predecessor, the National Virtual Observatory (NVO), have developed and operated a software infrastructure consisting of standards and protocols for data and science software applications. The Virtual Observatory (VO) makes it possible to develop robust software for the discovery, access, and analysis of astronomical data. Every major publicly funded research organization in the US and worldwide has deployed at least some components of the VO infrastructure; tens of thousands of VO-enabled queries for data are invoked daily against catalog, image, and spectral data collections; and groups within the community have developed tools and applications building upon the VO infrastructure. Further, NVO and VAO have helped ensure access to data internationally by co-founding the International Virtual Observatory Alliance (IVOA, http://ivoa.net). The products of the VAO are being archived in a publicly accessible repository. Several science tools developed by the VAO will continue to be supported by the organizations that developed them: the Iris spectral energy distribution package (SAO), the Data Discovery Tool (STScI/MAST, HEASARC), and the scalable cross-comparison service (IPAC). The final year of VAO is focused on development of the data access protocol for data cubes, creation of Python language bindings to VO services, and deployment of a cloud-like data storage service that links to VO data discovery tools (SciDrive). We encourage the community to make use of these tools and services, to extend and improve them, and to carry on with the vision for virtual astronomy: astronomical research enabled by easy access to distributed data and computational resources. Funding for VAO development and operations has been provided jointly by NSF and NASA since May 2010. NSF funding will end in September 2014, though with the possibility of competitive solicitations for VO-based tool development. NASA intends to maintain core VO services such as the resource registry (the index of VO-accessible data collections), monitoring services, and a website as part of the remit of HEASARC, IPAC (IRSA, NED), and MAST.

Summary of NASA Advanced Telescope and Observatory Capability Roadmap

NASA Technical Reports Server (NTRS)

Stahl, H. Phil; Feinberg, Lee

2006-01-01

The NASA Advanced Telescope and Observatory (ATO) Capability Roadmap addresses technologies necessary for NASA to enable future space telescopes and observatories operating in all electromagnetic bands, from x-rays to millimeter waves, and including gravity-waves. It lists capability priorities derived from current and developing Space Missions Directorate (SMD) strategic roadmaps. Technology topics include optics; wavefront sensing and control and interferometry; distributed and advanced spacecraft systems; cryogenic and thermal control systems; large precision structure for observatories; and the infrastructure essential to future space telescopes and observatories.

Summary of NASA Advanced Telescope and Observatory Capability Roadmap

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Feinberg, Lee

2007-01-01

The NASA Advanced Telescope and Observatory (ATO) Capability Roadmap addresses technologies necessary for NASA to enable future space telescopes and observatories operating in all electromagnetic bands, from x-rays to millimeter waves, and including gravity-waves. It lists capability priorities derived from current and developing Space Missions Directorate (SMD) strategic roadmaps. Technology topics include optics; wavefront sensing and control and interferometry; distributed and advanced spacecraft systems; cryogenic and thermal control systems; large precision structure for observatories; and the infrastructure essential to future space telescopes and observatories.

Global TIE: Developing a Virtual Network of Robotic Observatories for K-12 Education

NASA Astrophysics Data System (ADS)

Mayo, L. A.; Clark, G.

2001-11-01

Astronomy in grades K-12 is traditionally taught (if at all) using textbooks and a few simple hands-on activities. In addition, most students, by High School graduation, will never have even looked through the eyepiece of a telescope. The possibility now exists to establish a network of research grade telescopes, no longer useful to the professional astronomical community, that can be made accessible to schools all across the country through existing IT technologies and applications. These telescopes could provide unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns underutilized observatory facilities into valuable, state-of-the-art teaching centers. The NASA-sponsored Telescopes In Education (TIE, http://tie.jpl.nasa.gov) project has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. Global TIE integrates these telescopes seamlessly into one virtual observatory and provides the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J" for publication of results, and access to related educational materials provided by the TIE community. Global TIE provides unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns essentially unused observatory facilities into valuable, state-of-the-art teaching centers. This presentation describes the Global TIE Observatory data and organizational systems and details the technology, partnerships, operational capabilities, science applications, and learning opportunities that this powerful virtual observatory network will provide.

Creating Data that Never Die: Building a Spectrograph Data Pipeline in the Virtual Observatory Era

NASA Astrophysics Data System (ADS)

Mink, D. J.; Wyatt, W. F.; Roll, J. B.; Tokarz, S. P.; Conroy, M. A.; Caldwell, N.; Kurtz, M.; Geller, M. J.

2005-12-01

Data pipelines for modern complex astronomical instruments do not begin when the data is taken and end when it is delivered to the user. Information must flow between the observatory and the observer from the time a project is conceived and between the observatory and the world well past the time when the original observers have extracted all the information they want from the data. For the 300-fiber Hectospec low dispersion spectrograph on the MMT, the SAO Telescope Data Center is constructing a data pipeline which provides assistance from preparing and submitting observing proposals through observation, reduction, and analysis to publication and an afterlife in the Virtual Observatory. We will describe our semi-automatic pipeline and how it has evolved over the first nine months of operation.

Education Potential of the National Virtual Observatory

NASA Astrophysics Data System (ADS)

Christian, Carol

2006-12-01

Research in astronomy is blossoming with the availability of sophisticated instrumentation and tools aimed at breakthroughs in our understanding of the physical universe. Researchers can take advantage of the astronomical infrastructure, the National Virtual Observatory (NVO), for their investigations. . As well, data and tools available to the public are increasing through the distributed resources of observatories, academic institutions, computing facilities and educational organizations. Because Astronomy holds the public interest through engaging content and striking a cord with fundamental questions of human interest, it is a perfect context for science and technical education. Through partnerships we are cultivating, the NVO can be tuned for educational purposes.

Space-Time Coordinate Metadata for the Virtual Observatory Version 1.33

NASA Astrophysics Data System (ADS)

Rots, A. H.; Rots, A. H.

2007-10-01

This document provides a complete design description of the Space-Time Coordinate (STC) metadata for the Virtual Observatory. It explains the various components, highlights some implementation considerations, presents a complete set of UML diagrams, and discusses the relation between STC and certain other parts of the Data Model. Two serializations are discussed: XML Schema (STC-X) and String (STC-S); the former is an integral part of this Recommendation.

AstroGrid: Taverna in the Virtual Observatory .

NASA Astrophysics Data System (ADS)

Benson, K. M.; Walton, N. A.

This paper reports on the implementation of the Taverna workbench by AstroGrid, a tool for designing and executing workflows of tasks in the Virtual Observatory. The workflow approach helps astronomers perform complex task sequences with little technical effort. Visual approach to workflow construction streamlines highly complex analysis over public and private data and uses computational resources as minimal as a desktop computer. Some integration issues and future work are discussed in this article.

Catchment virtual observatory for sharing flow and transport models outputs: using residence time distribution to compare contrasting catchments

NASA Astrophysics Data System (ADS)

Thomas, Zahra; Rousseau-Gueutin, Pauline; Kolbe, Tamara; Abbott, Ben; Marcais, Jean; Peiffer, Stefan; Frei, Sven; Bishop, Kevin; Le Henaff, Geneviève; Squividant, Hervé; Pichelin, Pascal; Pinay, Gilles; de Dreuzy, Jean-Raynald

2017-04-01

The distribution of groundwater residence time in a catchment provides synoptic information about catchment functioning (e.g. nutrient retention and removal, hydrograph flashiness). In contrast with interpreted model results, which are often not directly comparable between studies, residence time distribution is a general output that could be used to compare catchment behaviors and test hypotheses about landscape controls on catchment functioning. In this goal, we created a virtual observatory platform called Catchment Virtual Observatory for Sharing Flow and Transport Model Outputs (COnSOrT). The main goal of COnSOrT is to collect outputs from calibrated groundwater models from a wide range of environments. By comparing a wide variety of catchments from different climatic, topographic and hydrogeological contexts, we expect to enhance understanding of catchment connectivity, resilience to anthropogenic disturbance, and overall functioning. The web-based observatory will also provide software tools to analyze model outputs. The observatory will enable modelers to test their models in a wide range of catchment environments to evaluate the generality of their findings and robustness of their post-processing methods. Researchers with calibrated numerical models can benefit from observatory by using the post-processing methods to implement a new approach to analyzing their data. Field scientists interested in contributing data could invite modelers associated with the observatory to test their models against observed catchment behavior. COnSOrT will allow meta-analyses with community contributions to generate new understanding and identify promising pathways forward to moving beyond single catchment ecohydrology. Keywords: Residence time distribution, Models outputs, Catchment hydrology, Inter-catchment comparison

Lockheed Solar Observatory and the Discovery of Moreton-Ramsey Waves

NASA Astrophysics Data System (ADS)

Tarbell, Theodore D.

2014-06-01

Moreton Waves are high-speed disturbances seen traveling away from large solar flares in H-alpha movies of the solar chromosphere. They were discovered by the observer Harry Ramsey in the late 1950s, and then published and publicized by the director Gail Moreton, both of the Lockheed Solar Observatory in the Hollywood Hills of Southern California. These efforts established the scientific reputation and secured continuing funding of the observatory, whose present-day successor is the Lockheed Martin Solar and Astrophysics Lab in Palo Alto. Moreton waves are rare, and there was limited interest in them until the EIT instrument on SOHO began seeing large numbers of similar waves in the corona in the late 1990s. The exact relation between the two observations is still a research topic today. This talk will describe some of the history of the observatory and the discovery and early interpretation of the waves.

Estimation of the state of solar activity type stars by virtual observations of CrAVO

NASA Astrophysics Data System (ADS)

Dolgov, A. A.; Shlyapnikov, A. A.

2012-05-01

The results of precosseing of negatives with direct images of the sky from CrAO glass library are presented in this work, which became a part of on-line archive of the Crimean Astronomical Virtual Observatory (CrAVO). Based on the obtained data, the parameters of dwarf stars have been estimated, included in the catalog "Stars with solar-type activity" (GTSh10). The following matters are considered: searching methodology of negatives with positions of studied stars and with calculated limited magnitude; image viewing and reduction with the facilities of the International Virtual Observatory; the preliminary results of the photometry of studied objects.

CubeIndexer: Indexer for regions of interest in data cubes

NASA Astrophysics Data System (ADS)

Chilean Virtual Observatory; Araya, Mauricio; Candia, Gabriel; Gregorio, Rodrigo; Mendoza, Marcelo; Solar, Mauricio

2015-12-01

CubeIndexer indexes regions of interest (ROIs) in data cubes reducing the necessary storage space. The software can process data cubes containing megabytes of data in fractions of a second without human supervision, thus allowing it to be incorporated into a production line for displaying objects in a virtual observatory. The software forms part of the Chilean Virtual Observatory (ChiVO) and provides the capability of content-based searches on data cubes to the astronomical community.

Use of Statistical Estimators as Virtual Observatory Search ParametersEnabling Access to Solar and Planetary Resources through the Virtual Observatory

NASA Astrophysics Data System (ADS)

Merka, J.; Dolan, C. F.

2015-12-01

Finding and retrieving space physics data is often a complicated taskeven for publicly available data sets: Thousands of relativelysmall and many large data sets are stored in various formats and, inthe better case, accompanied by at least some documentation. VirtualHeliospheric and Magnetospheric Observatories (VHO and VMO) help researches by creating a single point of uniformdiscovery, access, and use of heliospheric (VHO) and magnetospheric(VMO) data.The VMO and VHO functionality relies on metadata expressed using theSPASE data model. This data model is developed by the SPASE WorkingGroup which is currently the only international group supporting globaldata management for Solar and Space Physics. The two Virtual Observatories(VxOs) have initiated and lead a development of a SPASE-related standardnamed SPASE Query Language for provided a standard way of submittingqueries and receiving results.The VMO and VHO use SPASE and SPASEQL for searches based on various criteria such as, for example, spatial location, time of observation, measurement type, parameter values, etc. The parameter values are represented by their statisticalestimators calculated typically over 10-minute intervals: mean, median, standard deviation, minimum, and maximum. The use of statistical estimatorsenables science driven data queries that simplify and shorten the effort tofind where and/or how often the sought phenomenon is observed, as we will present.

Science Initiatives of the US Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Hanisch, R. J.

2012-09-01

The United States Virtual Astronomical Observatory program is the operational facility successor to the National Virtual Observatory development project. The primary goal of the US VAO is to build on the standards, protocols, and associated infrastructure developed by NVO and the International Virtual Observatory Alliance partners and to bring to fruition a suite of applications and web-based tools that greatly enhance the research productivity of professional astronomers. To this end, and guided by the advice of our Science Council (Fabbiano et al. 2011), we have focused on five science initiatives in the first two years of VAO operations: 1) scalable cross-comparisons between astronomical source catalogs, 2) dynamic spectral energy distribution construction, visualization, and model fitting, 3) integration and periodogram analysis of time series data from the Harvard Time Series Center and NASA Star and Exoplanet Database, 4) integration of VO data discovery and access tools into the IRAF data analysis environment, and 5) a web-based portal to VO data discovery, access, and display tools. We are also developing tools for data linking and semantic discovery, and have a plan for providing data mining and advanced statistical analysis resources for VAO users. Initial versions of these applications and web-based services are being released over the course of the summer and fall of 2011, with further updates and enhancements planned for throughout 2012 and beyond.

The Science of Gravitational Waves with Space Observatories

NASA Technical Reports Server (NTRS)

Thorpe, James Ira

2013-01-01

After decades of effort, direct detection of gravitational waves from astrophysical sources is on the horizon. Aside from teaching us about gravity itself, gravitational waves hold immense promise as a tool for general astrophysics. In this talk I will provide an overview of the science enabled by a space-based gravitational wave observatory sensitive in the milli-Hertz frequency band including the nature and evolution of massive black holes and their host galaxies, the demographics of stellar remnant compact objects in the Milky Way, and the behavior of gravity in the strong-field regime. I will also summarize the current status of efforts in the US and Europe to implement a space-based gravitational wave observatory.

The National Virtual Observatory

NASA Astrophysics Data System (ADS)

Hanisch, Robert J.

2001-06-01

The National Virtual Observatory is a distributed computational facility that will provide access to the ``virtual sky''-the federation of astronomical data archives, object catalogs, and associated information services. The NVO's ``virtual telescope'' is a common framework for requesting, retrieving, and manipulating information from diverse, distributed resources. The NVO will make it possible to seamlessly integrate data from the new all-sky surveys, enabling cross-correlations between multi-Terabyte catalogs and providing transparent access to the underlying image or spectral data. Success requires high performance computational systems, high bandwidth network services, agreed upon standards for the exchange of metadata, and collaboration among astronomers, astronomical data and information service providers, information technology specialists, funding agencies, and industry. International cooperation at the onset will help to assure that the NVO simultaneously becomes a global facility. .

Interferometry

NASA Technical Reports Server (NTRS)

Ridgway, Stephen; Wilson, Robert W.; Begelman, Mitchell C.; Bender, Peter; Burke, Bernard F.; Cornwell, Tim; Drever, Ronald; Dyck, H. Melvin; Johnston, Kenneth J.; Kibblewhite, Edward

1991-01-01

The following recommended programs are reviewed: (1) infrared and optical interferometry (a ground-based and space programs); (2) compensation for the atmosphere with adaptive optics (a program for development and implementation of adaptive optics); and (3) gravitational waves (high frequency gravitational wave sources (LIGO), low frequency gravitational wave sources (LAGOS), a gravitational wave observatory program, laser gravitational wave observatory in space, and technology development during the 1990's). Prospects for international collaboration and related issues are also discussed.

Graphics interfaces and numerical simulations: Mexican Virtual Solar Observatory

NASA Astrophysics Data System (ADS)

Hernández, L.; González, A.; Salas, G.; Santillán, A.

2007-08-01

Preliminary results associated to the computational development and creation of the Mexican Virtual Solar Observatory (MVSO) are presented. Basically, the MVSO prototype consists of two parts: the first, related to observations that have been made during the past ten years at the Solar Observation Station (EOS) and at the Carl Sagan Observatory (OCS) of the Universidad de Sonora in Mexico. The second part is associated to the creation and manipulation of a database produced by numerical simulations related to solar phenomena, we are using the MHD ZEUS-3D code. The development of this prototype was made using mysql, apache, java and VSO 1.2. based GNU and `open source philosophy'. A graphic user interface (GUI) was created in order to make web-based, remote numerical simulations. For this purpose, Mono was used, because it is provides the necessary software to develop and run .NET client and server applications on Linux. Although this project is still under development, we hope to have access, by means of this portal, to other virtual solar observatories and to be able to count on a database created through numerical simulations or, given the case, perform simulations associated to solar phenomena.

Using Virtual Observatory Services in Sky View

NASA Technical Reports Server (NTRS)

McGlynn, Thomas A.

2007-01-01

For over a decade Skyview has provided astronomers and the public with easy access to survey and imaging data from all wavelength regimes. SkyView has pioneered many of the concepts that underlie the Virtual Observatory. Recently SkyView has been released as a distributable package which uses VO protocols to access image and catalog services. This chapter describes how to use the Skyview as a local service and how to customize it to access additional VO services and local data.

The Organization and Management of the Virtual Astronomical Observatory

NASA Technical Reports Server (NTRS)

Berriman, G. Bruce; Hanisch, Robert J.; Lazio, T. Joseph W.; Szalay, Alexander; Fabbiano, Giussepina

2012-01-01

The U.S. Virtual Astronomical Observatory (VAO; http://www.us-vao.org/) has been in operation since May 2010. Its goal is to enable new science through efficient integration of distributed multi-wavelength data. This paper describes the management and organization of the VAO, and emphasizes the techniques used to ensure efficiency in a distributed organization. Management methods include using an annual program plan as the basis for establishing contracts with member organizations, regular communication, and monitoring of processes.

The organization and management of the Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Berriman, G. Bruce; Hanisch, Robert J.; Lazio, T. Joseph W.; Szalay, Alexander; Fabbiano, Giuseppina

2012-09-01

The U.S. Virtual Astronomical Observatory (VAO; http://www.us-vao.org/) has been in operation since May 2010. Its goal is to enable new science through efficient integration of distributed multi-wavelength data. This paper describes the management and organization of the VAO, and emphasizes the techniques used to ensure efficiency in a distributed organization. Management methods include using an annual program plan as the basis for establishing contracts with member organizations, regular communication, and monitoring of processes.

The Virtual Space Physics Observatory: Quick Access to Data and Tools

NASA Technical Reports Server (NTRS)

Cornwell, Carl; Roberts, D. Aaron; McGuire, Robert E.

2006-01-01

The Virtual Space Physics Observatory (VSPO; see http://vspo.gsfc.nasa.gov) has grown to provide a way to find and access about 375 data products and services from over 100 spacecraft/observatories in space and solar physics. The datasets are mainly chosen to be the most requested, and include most of the publicly available data products from operating NASA Heliophysics spacecraft as well as from solar observatories measuring across the frequency spectrum. Service links include a "quick orbits" page that uses SSCWeb Web Services to provide a rapid answer to questions such as "What spacecraft were in orbit in July 1992?" and "Where were Geotail, Cluster, and Polar on 2 June 2001?" These queries are linked back to the data search page. The VSPO interface provides many ways of looking for data based on terms used in a registry of resources using the SPASE Data Model that will be the standard for Heliophysics Virtual Observatories. VSPO itself is accessible via an API that allows other applications to use it as a Web Service; this has been implemented in one instance using the ViSBARD visualization program. The VSPO will become part of the Space Physics Data Facility, and will continue to expand its access to data. A challenge for all VOs will be to provide uniform access to data at the variable level, and we will be addressing this question in a number of ways.

NASA capabilities roadmap: advanced telescopes and observatories

NASA Technical Reports Server (NTRS)

Feinberg, Lee D.

2005-01-01

The NASA Advanced Telescopes and Observatories (ATO) Capability Roadmap addresses technologies necessary for NASA to enable future space telescopes and observatories collecting all electromagnetic bands, ranging from x-rays to millimeter waves, and including gravity-waves. It has derived capability priorities from current and developing Space Missions Directorate (SMD) strategic roadmaps and, where appropriate, has ensured their consistency with other NASA Strategic and Capability Roadmaps. Technology topics include optics; wavefront sensing and control and interferometry; distributed and advanced spacecraft systems; cryogenic and thermal control systems; large precision structure for observatories; and the infrastructure essential to future space telescopes and observatories.

The Virtual Observatory: Retrospective and Prospectus

NASA Astrophysics Data System (ADS)

Hanisch, R. J.

2010-12-01

At the ADASS XV in San Lorenzo de El Escorial, Spain, in October 2005, I gave an overview of the accomplishments of the Virtual Observatory initiatives and discussed the imminent transition from development to operations. That transition remains on the horizon for the US Virtual Observatory, and VO projects worldwide have encountered various programmatic challenges. The successes of the Virtual Observatory are many, but thus far are primarily of a technical nature. We have developed a data discovery and data access infrastructure that has been taken up by data centers and observatories around the world. We have web-based interfaces, downloadable toolkits and applications, a security and restricted access capability, standard vocabularies, a sophisticated messaging and alert system for transient events, and the ability for applications to exchange messages and work together seamlessly. This has been accomplished through a strong collaboration between astronomers and information technology specialists. We have been less successful engaging the astronomical researcher. Relatively few papers have been published based on VO-enabled research, and many astronomers remain unfamiliar with the capabilities of the VO despite active training and tutorial programs hosted by several of the major VO projects. As we (finally!) enter the operational phase of the VO, we need to focus on areas that have contributed to the limited take-up of the VO amongst active scientists, such as ease of use, reliability, and consistency. We need to routinely test VO services for aliveness and adherence to standards, working with data providers to fix errors and otherwise removing non-compliant services from those seen by end-users. Technical developments will need to be motivated and prioritized based on scientific utility. We need to continue to embrace new technology and employ it in a context that focuses on research productivity.

Facilitating Heliophysics Research by the Virtual Wave Observatory (VWO) Context Data Search Capability

NASA Technical Reports Server (NTRS)

Fung, Shing F.; Shao, Xi; Garcia, Leonard N.; Galkin, Ivan A.; Benson, Robert F.

2009-01-01

Wave phenomena, ranging from freely propagating electromagnetic radiation (e.g., solar radio bursts, AKR) to plasma wave modes trapped in various plasma regimes (e.g., whistlers, Langmuir and ULF waves) and atmospheric gravity waves, are ubiquitous in the heliosphere. Because waves can propagate, wave data obtained at a given observing location may pertain to wave oscillations generated locally or from afar. While wave data analysis requires knowledge of wave characteristics specific to different wave modes, the search for appropriate data for heliophysics wave studies also requires knowledge of wave phenomena. In addition to deciding whether the interested wave activity is electrostatic (i.e., locally trapped) or electromagnetic (with propagation over distances), considerations must be given to the dependence of the wave activity on observer's location or viewing geometry, propagating frequency range and whether the wave data were acquired by passive or active observations. Occurances of natural wave emissions i the magnetosphere (e.g, auroral kilometric radiation) are often dependent also on the state (e.e., context) of the magnetosphere that varies with the changing solar wind, IMF and geomagnetic conditions. Fung and Shao [2008] showed recently that magnetospheric state can be specified by a set of suitably time-shifted solar wind, IMF and the multi-scale geomagnetic response parameters. These parameters form a magnetospheric state vector that provides the basis for searching magnetospheric wave data by their context conditions. Using the IMAGE Radio Plasma Imager (RPI) data and the NASA Magnetospheric State Query System (MSOS) [Fung, 2004], this presentation demonstrates the VWO context data search capability under development and solicits feedback from the Heliophysics research community for improvements.

First targeted search for gravitational-wave bursts from core-collapse supernovae in data of first-generation laser interferometer detectors

NASA Astrophysics Data System (ADS)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corpuz, A.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Holz, D. E.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Islas, G.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, K.; Kalaghatgi, C. V.; Kalmus, P.; Kalogera, V.; Kamaretsos, I.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J.; Kim, K.; Kim, Nam-Gyu; Kim, Namjun; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Kokeyama, K.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B. M.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Loew, K.; Logue, J.; Lombardi, A. L.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lück, H.; Lundgren, A. P.; Luo, J.; Lynch, R.; Ma, Y.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R. M.; Mageswaran, M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mendoza-Gandara, D.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, K. N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nedkova, K.; Nelemans, G.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Pereira, R.; Perreca, A.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Ricci, F.; Riles, K.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Santamaria, L.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Setyawati, Y.; Sevigny, A.; Shaddock, D. A.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D. J.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Wright, J. L.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, F.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration

2016-11-01

We present results from a search for gravitational-wave bursts coincident with two core-collapse supernovae observed optically in 2007 and 2011. We employ data from the Laser Interferometer Gravitational-wave Observatory (LIGO), the Virgo gravitational-wave observatory, and the GEO 600 gravitational-wave observatory. The targeted core-collapse supernovae were selected on the basis of (1) proximity (within approximately 15 Mpc), (2) tightness of observational constraints on the time of core collapse that defines the gravitational-wave search window, and (3) coincident operation of at least two interferometers at the time of core collapse. We find no plausible gravitational-wave candidates. We present the probability of detecting signals from both astrophysically well-motivated and more speculative gravitational-wave emission mechanisms as a function of distance from Earth, and discuss the implications for the detection of gravitational waves from core-collapse supernovae by the upgraded Advanced LIGO and Virgo detectors.

VESPA: Developing the Planetary Science Virtual Observatory in H2020

NASA Astrophysics Data System (ADS)

Erard, S.; Cecconi, B.; Le Sidaner, P.; Capria, T.; Rossi, A. P.; Schmitt, B.; André, N.; Vandaele, A.-C.; Scherf, M.; Hueso, R.; Maattanen, A.; Thuillot, W.; Achilleos, N.; Marmo, C.; Santolik, O.; Benson, K.; Bollard, Ph.

2015-10-01

The Europlanet H2020 programme will develop a research infrastructure in Horizon 2020. The programme includes a follow-on to the FP7 activity aimed at developing the Planetary Science Virtual Observatory (VO). This activity is called VESPA, which stands for Virtual European Solar and Planetary Access. Building on the IDIS activity of Europlanet FP7, VESPA will distribute more data, will improve the connected tools and infrastructure, and will help developing a community of both users and data providers. One goal of the Europlanet FP7 programme was to set the basis for a European Virtual Observatory in Planetary Science. A prototype has been set up during FP7, most of the activity being dedicated to the definition of standards to handle data in this field. The aim was to facilitate searches in big archives as well as sparse databases, to make on-line data access and visualization possible, and to allow small data providers to make their data available in an interoperable environment with minimum effort. This system makes intensive use of studies and developments led in Astronomy (IVOA), Solar Science (HELIO), plasma physics (SPASE), and space archive services (IPDA). It remains consistent with extensions of IVOA standards.

VESPA: developing the planetary science Virtual Observatory in H2020

NASA Astrophysics Data System (ADS)

Erard, Stéphane; Cecconi, Baptiste; Le Sidaner, Pierre; Capria, Teresa; Rossi, Angelo Pio

2016-04-01

The Europlanet H2020 programme will develop a research infrastructure in Horizon 2020. The programme includes a follow-on to the FP7 activity aimed at developing the Planetary Science Virtual Observatory (VO). This activity is called VESPA, which stands for Virtual European Solar and Planetary Access. Building on the IDIS activity of Europlanet FP7, VESPA will distribute more data, will improve the connected tools and infrastructure, and will help developing a community of both users and data providers. One goal of the Europlanet FP7 programme was to set the basis for a European Virtual Observatory in Planetary Science. A prototype has been set up during FP7, most of the activity being dedicated to the definition of standards to handle data in this field. The aim was to facilitate searches in big archives as well as sparse databases, to make on-line data access and visualization possible, and to allow small data providers to make their data available in an interoperable environment with minimum effort. This system makes intensive use of studies and developments led in Astronomy (IVOA), Solar Science (HELIO), plasma physics (SPASE), and space archive services (IPDA). It remains consistent with extensions of IVOA standards.

Spectroscopic analysis in the virtual observatory environment with SPLAT-VO

NASA Astrophysics Data System (ADS)

Škoda, P.; Draper, P. W.; Neves, M. C.; Andrešič, D.; Jenness, T.

2014-11-01

SPLAT-VO is a powerful graphical tool for displaying, comparing, modifying and analysing astronomical spectra, as well as searching and retrieving spectra from services around the world using Virtual Observatory (VO) protocols and services. The development of SPLAT-VO started in 1999, as part of the Starlink StarJava initiative, sometime before that of the VO, so initial support for the VO was necessarily added once VO standards and services became available. Further developments were supported by the Joint Astronomy Centre, Hawaii until 2009. Since end of 2011 development of SPLAT-VO has been continued by the German Astrophysical Virtual Observatory, and the Astronomical Institute of the Academy of Sciences of the Czech Republic. From this time several new features have been added, including support for the latest VO protocols, along with new visualization and spectra storing capabilities. This paper presents the history of SPLAT-VO, its capabilities, recent additions and future plans, as well as a discussion on the motivations and lessons learned up to now.

A Prototype Publishing Registry for the Virtual Observatory

NASA Astrophysics Data System (ADS)

Williamson, R.; Plante, R.

2004-07-01

In the Virtual Observatory (VO), a registry helps users locate resources, such as data and services, in a distributed environment. A general framework for VO registries is now under development within the International Virtual Observatory Alliance (IVOA) Registry Working Group. We present a prototype of one component of this framework: the publishing registry. The publishing registry allows data providers to expose metadata descriptions of their resources to the VO environment. Searchable registries can harvest the metadata from many publishing registries and make them searchable by users. We have developed a prototype publishing registry that data providers can install at their sites to publish their resources. The descriptions are exposed using the Open Archive Initiative (OAI) Protocol for Metadata Harvesting. Automating the input of metadata into registries is critical when a provider wishes to describe many resources. We illustrate various strategies for such automation, both currently in use and planned for the future. We also describe how future versions of the registry can adapt automatically to evolving metadata schemas for describing resources.

Development of Armenian-Georgian Virtual Observatory

NASA Astrophysics Data System (ADS)

Mickaelian, Areg; Kochiashvili, Nino; Astsatryan, Hrach; Harutyunian, Haik; Magakyan, Tigran; Chargeishvili, Ketevan; Natsvlishvili, Rezo; Kukhianidze, Vasil; Ramishvili, Giorgi; Sargsyan, Lusine; Sinamyan, Parandzem; Kochiashvili, Ia; Mikayelyan, Gor

2009-10-01

The Armenian-Georgian Virtual Observatory (ArGVO) project is the first initiative in the world to create a regional VO infrastructure based on national VO projects and regional Grid. The Byurakan and Abastumani Astrophysical Observatories are scientific partners since 1946, after establishment of the Byurakan observatory . The Armenian VO project (ArVO) is being developed since 2005 and is a part of the International Virtual Observatory Alliance (IVOA). It is based on the Digitized First Byurakan Survey (DFBS, the digitized version of famous Markarian survey) and other Armenian archival data. Similarly, the Georgian VO will be created to serve as a research environment to utilize the digitized Georgian plate archives. Therefore, one of the main goals for creation of the regional VO is the digitization of large amounts of plates preserved at the plate stacks of these two observatories. The total amount of plates is more than 100,000 units. Observational programs of high importance have been selected and some 3000 plates will be digitized during the next two years; the priority is being defined by the usefulness of the material for future science projects, like search for new objects, optical identifications of radio, IR, and X-ray sources, study of variability and proper motions, etc. Having the digitized material in VO standards, a VO database through the regional Grid infrastructure will be active. This partnership is being carried out in the framework of the ISTC project A-1606 "Development of Armenian-Georgian Grid Infrastructure and Applications in the Fields of High Energy Physics, Astrophysics and Quantum Physics".

Evaluating a NoSQL Alternative for Chilean Virtual Observatory Services

NASA Astrophysics Data System (ADS)

Antognini, J.; Araya, M.; Solar, M.; Valenzuela, C.; Lira, F.

2015-09-01

Currently, the standards and protocols for data access in the Virtual Observatory architecture (DAL) are generally implemented with relational databases based on SQL. In particular, the Astronomical Data Query Language (ADQL), language used by IVOA to represent queries to VO services, was created to satisfy the different data access protocols, such as Simple Cone Search. ADQL is based in SQL92, and has extra functionality implemented using PgSphere. An emergent alternative to SQL are the so called NoSQL databases, which can be classified in several categories such as Column, Document, Key-Value, Graph, Object, etc.; each one recommended for different scenarios. Within their notable characteristics we can find: schema-free, easy replication support, simple API, Big Data, etc. The Chilean Virtual Observatory (ChiVO) is developing a functional prototype based on the IVOA architecture, with the following relevant factors: Performance, Scalability, Flexibility, Complexity, and Functionality. Currently, it's very difficult to compare these factors, due to a lack of alternatives. The objective of this paper is to compare NoSQL alternatives with SQL through the implementation of a Web API REST that satisfies ChiVO's needs: a SESAME-style name resolver for the data from ALMA. Therefore, we propose a test scenario by configuring a NoSQL database with data from different sources and evaluating the feasibility of creating a Simple Cone Search service and its performance. This comparison will allow to pave the way for the application of Big Data databases in the Virtual Observatory.

Virtual Energetic Particle Observatory for the Heliospheric Data Environment

NASA Technical Reports Server (NTRS)

Cooper, J. F.; Armstrong, T. P.; Hill, M. E.; Lal, N.; McGuire, R. E.; McKibben, R. B.; Narock, T. W.; Szabo, A.; Tranquille, C.

2007-01-01

The heliosphere is pervaded by interplanetary energetic particles, traditionally also called cosmic rays, from solar, internal heliospheric, and galactic sources. The particles species of interest to heliophysics extend from plasma energies to the GeV energies of galactic cosmic rays still measurably affected by heliospheric modulation and the still higher energies contributing to atmospheric ionization. The NASA and international Heliospheric Network of operational and legacy spacecraft measures interplanetary fluxes of these particles. Spatial coverage extends from the inner heliosphere and geospace to the heliosheath boundary region now being traversed by Voyager 1 and soon by Voyager 2. Science objectives include investigation of solar flare and coronal mass ejection events, acceleration and transport of interplanetary particles within the inner heliosphere, cosmic ray interactions with planetary surfaces and atmospheres, sources of suprathermal and anomalous cosmic ray ions in the outer heliosphere, and solar cycle modulation of galactic cosmic rays. The Virtual Energetic Particle Observatory (VEPO) will improve access and usability of selected spacecraft and sub-orbital NASA heliospheric energetic particle data sets as a newly approved effort within the evolving heliophysics virtual observatory environment. In this presentation, we will describe current VEPO science requirements, our initial priorities and an overview of our strategy to implement VEPO rapidly and at minimal cost by working within the high-level framework of the Virtual Heliospheric Observatory (VHO). VEPO will also leverage existing data services of NASA's Space Physics Data Facility and other existing capabilities of the U.S. and international heliospheric research communities.

The Role of the Virtual Astronomical Observatory in the Era of Big Data

NASA Astrophysics Data System (ADS)

Berriman, G. B.; Hanisch, R. J.; Lazio, T. J.

2013-01-01

The Virtual Observatory (VO) is realizing global electronic integration of astronomy data. The rapid growth in the size and complexity of data sets is transforming the computing landscape in astronomy. One of the long-term goals of the U.S. VO project, the Virtual Astronomical Observatory (VAO), is development of an information backbone that responds to this growth. Such a backbone will, when complete, provide innovative mechanisms for fast discovery of, and access to, massive data sets, and services that enable distributed storage, publication processing of large datasets. All these services will be built so that new projects can incorporate them as part of their data management and processing plans. Services under development to date include a general purpose indexing scheme for fast access to data sets, a cross-comparison engine that operate on catalogs of 1 billion records or more, and an interface for managing distributed data sets and connecting them to data discovery and analysis tools. The VAO advises projects on technology solutions for their data access and processing needs, and recently advised the Sagan Workshop on using cloud computing to support hands-on data analysis sessions for 150+ participants. Acknowledgements: The Virtual Astronomical Observatory (VAO) is managed by the VAO, LLC, a non-profit company established as a partnership of the Associated Universities, Inc. and the Association of Universities for Research in Astronomy, Inc. The VAO is sponsored by the National Science Foundation and the National Aeronautics and Space Administration.

Virtual Observatory and Colitec Software: Modules, Features, Methods

NASA Astrophysics Data System (ADS)

Pohorelov, A. V.; Khlamov, S. V.; Savanevych, V. E.; Briukhovetskyi, A. B.; Vlasenko, V. P.

In this article we described complex processing system created by the CoLiTec project. This system includes features, user-friendly tools for processing control, results reviewing, integration with online catalogs and a lot of different computational modules that are based on the developed methods. Some of them are described in the article.The main directions of the CoLiTec software development are the Virtual Observatory, software for automated asteroids and comets detection and software for brightness equalization.The CoLiTec software is widely used in a number of observatories in the CIS. It has been used in about 700 000 observations, during which 1560 asteroids, including 5 NEO, 21 Trojan asteroids of Jupiter, 1 Centaur and four comets were discovered.

Understanding the Physical Nature of Coronal "EIT Waves"

NASA Astrophysics Data System (ADS)

Long, D. M.; Bloomfield, D. S.; Chen, P.-F.; Downs, C.; Gallagher, P. T.; Kwon, R.-Y.; Vanninathan, K.; Veronig, A.; Vourlidas, A.; Vrsnak, B.; Warmuth, A.; Zic, T.

2016-10-01

For almost 20 years the physical nature of globally-propagating waves in the solar corona (commonly called "EIT waves") has been controversial and subject to debate. Additional theories have been proposed throughout the years to explain observations that did not fit with the originally proposed fast-mode wave interpretation. However, the incompatibility of observations made using the Extreme-ultraviolet Imaging Telescope (EIT) on the Solar and Heliospheric Observatory with the fast-mode wave interpretation have been challenged by differing viewpoints from the Solar Terrestrial Relations Observatory spacecraft and higher spatial/temporal resolution data from the Solar Dynamics Observatory. In this paper, we reexamine the theories proposed to explain "EIT waves" to identify measurable properties and behaviours that can be compared to current and future observations. Most of us conclude that "EIT waves" are best described as fast-mode large-amplitude waves/shocks, which are initially driven by the impulsive expansion of an erupting coronal mass ejection in the low corona.

Understanding the Physical Nature of Coronal "EIT Waves".

PubMed

Long, D M; Bloomfield, D S; Chen, P F; Downs, C; Gallagher, P T; Kwon, R-Y; Vanninathan, K; Veronig, A M; Vourlidas, A; Vršnak, B; Warmuth, A; Žic, T

2017-01-01

For almost 20 years the physical nature of globally propagating waves in the solar corona (commonly called "EIT waves") has been controversial and subject to debate. Additional theories have been proposed over the years to explain observations that did not agree with the originally proposed fast-mode wave interpretation. However, the incompatibility of observations made using the Extreme-ultraviolet Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory with the fast-mode wave interpretation was challenged by differing viewpoints from the twin Solar Terrestrial Relations Observatory spacecraft and data with higher spatial and temporal resolution from the Solar Dynamics Observatory . In this article, we reexamine the theories proposed to explain EIT waves to identify measurable properties and behaviours that can be compared to current and future observations. Most of us conclude that the so-called EIT waves are best described as fast-mode large-amplitude waves or shocks that are initially driven by the impulsive expansion of an erupting coronal mass ejection in the low corona.

Implementing an Education and Outreach Program for the Gemini Observatory in Chile.

NASA Astrophysics Data System (ADS)

Garcia, M. A.

2006-08-01

Beginning in 2001, the Gemini Observatory began the development of an innovative and aggressive education and outreach program at its Southern Hemisphere site in northern Chile. A principal focus of this effort is centered on local education and outreach to communities surrounding the observatory and its base facility in La Serena Chile. Programs are now established with local schools using two portable StarLab planetaria, an internet-based teacher exchange called StarTeachers and multiple partnerships with local educational institutions. Other elements include a CD-ROM-based virtual tour that allows students, teachers and the public to experience the observatory's sites in Chile and Hawaii. This virtual environment allows interaction using a variety of immersive scenarios such as a simulated observation using real data from Gemini. Pilot projects like "Live from Gemini" are currently being developed which use internet videoconferencing technologies to bring the observatory's facilities into classrooms at universities and remote institutions. Lessons learned from the implementation of these and other programs will be introduced and the challenges of developing educational programming in a developing country will be shared.

VizieR Online Data Catalog: NLTE spectral analysis of white dwarf G191-B2B (Rauch+, 2013)

NASA Astrophysics Data System (ADS)

Rauch, T.; Werner, K.; Bohlin, R.; Kruk, J. W.

2013-08-01

In the framework of the Virtual Observatory, the German Astrophysical Virtual Observatory developed the registered service TheoSSA. It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code. In case of the DA white dwarf G191-B2B, we demonstrate that the model reproduces not only its overall continuum shape but also the numerous metal lines exhibited in its ultraviolet spectrum. (3 data files).

The Sky is for Everyone — Outreach and Education with the Virtual Observatory

NASA Astrophysics Data System (ADS)

Freistetter, F.; Iafrate, G.; Ramella, M.; Aida-Wp5 Team

2010-12-01

The Virtual Observatory (VO) is an international project to collect astronomical data (images, spectra, simulations, mission-logs, etc.), organise them and develop tools that let astronomers access this huge amount of information. The VO not only simplifies the work of professional astronomers, it is also a valuable tool for education and public outreach. For teachers and astronomers who actively promote astronomy to the public, the VO is a great opportunity to access and use real astronomical data, and have a taste of the daily life of astronomers.

The Virtual Solar Observatory: Progress and Diversions

NASA Astrophysics Data System (ADS)

Gurman, Joseph B.; Bogart, R. S.; Amezcua, A.; Hill, Frank; Oien, Niles; Davey, Alisdair R.; Hourcle, Joseph; Mansky, E.; Spencer, Jennifer L.

2017-08-01

The Virtual Solar Observatory (VSO) is a known and useful method for identifying and accessing solar physics data online. We review current "behind the scenes" work on the VSO, including the addition of new data providers and the return of access to data sets to which service was temporarily interrupted. We also report on the effect on software development efforts when government IT “security” initiatives impinge on finite resoruces. As always, we invite SPD members to identify data sets, services, and interfaces they would like to see implemented in the VSO.

The GTC Public Archive

NASA Astrophysics Data System (ADS)

Alacid, J. Manuel; Solano, Enrique

2015-12-01

The Gran Telescopio Canarias (GTC) archive is operational since November 2011. The archive, maintained by the Data Archive Unit at CAB in the framework of the Spanish Virtual Observatory project, provides access to both raw and science ready data and has been designed in compliance with the standards defined by the International Virtual Observatory Alliance (IVOA) to guarantee a high level of data accessibility and handling. In this presentation I will describe the main capabilities the GTC archive offers to the community, in terms of functionalities and data collections, to carry out an efficient scientific exploitation of GTC data.

Searching for Fast Radio Bursts with the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)

NASA Astrophysics Data System (ADS)

Fisher, Ryan Patrick; Hughey, Brennan; Howell, Eric; LIGO Collaboration

2018-01-01

Although Fast Radio Bursts (FRB) are being detected with increasing frequency, their progenitor systems are still mostly a mystery. We present the plan to conduct targeted searches for gravitational-wave counterparts to these FRB events in the data from the first and second observing runs of the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO).

Using Virtual Astronomical Observatory Tools for Astronomy 101

NASA Astrophysics Data System (ADS)

Mighell, Kenneth J.; Garmany, K.; Larson, K.; Eastwood, K. D.

2009-01-01

The Virtual Observatory provides several tools that are useful for educators. With these tools, instructors can easily provide real data to students in an environment that engages student curiosity and builds student understanding. In this poster we demonstrate how the tools Aladin and TOPCAT can be used to enhance astronomy education. The Aladin Sky Atlas is a Virtual Observatory portal from the CDS that displays images, superimposes catalogs, and provides interactive access to data. For illustration, we show an exercise for non-science majors in a college-level astronomy course that introduces students to the HR diagram of star clusters. After launching the pre-loaded Aladin applet, students select their own stars, connecting visual cues of brightness and color to the conceptual meaning behind a quantitative HR diagram. TOPCAT can be linked with Aladin on the desktop to let students analyze their data, perform calculations, and create professional-quality graphs. The basic exercise can be easily expanded to address other learning objectives and provides a launching point for students to access, visualize, and explore multi-wavelength data as they continue in astronomy. As a second example, we show an exercise that uses TOPCAT to do three-dimensional plotting of the positions of open and globular cluster to illustrate galactic structure. Detailed information is available at the following website: http://www.noao.edu/staff/mighell/nvoss2008/ . This research was done at the 2008 U.S. National Virtual Observatory Summer School which was held in Santa Fe, New Mexico on September 3 - 11, 2008 and was sponsored by the National Science Foundation.

The database of the Nikolaev Astronomical Observatory as a unit of an international virtual observatory

NASA Astrophysics Data System (ADS)

Protsyuk, Yu.; Pinigin, G.; Shulga, A.

2005-06-01

Results of the development and organization of the digital database of the Nikolaev Astronomical Observatory (NAO) are presented. At present, three telescopes are connected to the local area network of NAO. All the data obtained, and results of data processing are entered into the common database of NAO. The daily average volume of new astronomical information obtained from the CCD instruments ranges from 300 MB up to 2 GB, depending on the purposes and conditions of observations. The overwhelming majority of the data are stored in the FITS format. Development and further improvement of storage standards, procedures of data handling and data processing are being carried out. It is planned to create an astronomical web portal with the possibility to have interactive access to databases and telescopes. In the future, this resource may become a part of an international virtual observatory. There are the prototypes of search tools with the use of PHP and MySQL. Efforts for getting more links to the Internet are being made.

The Virtual Solar Observatory: What Are We Up To Now?

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Hill, F.; Suarez-Sola, F.; Bogart, R.; Amezcua, A.; Martens, P.; Hourcle, J.; Hughitt, K.; Davey, A.

2012-01-01

In the nearly ten years of a functional Virtual Solar Observatory (VSO), http://virtualsolar.org/ we have made it possible to query and access sixty-seven distinct solar data products and several event lists from nine spacecraft and fifteen observatories or observing networks. We have used existing VSO technology, and developed new software, for a distributed network of sites caching and serving SDO HMI and/ or AlA data. We have also developed an application programming interface (API) that has enabled VSO search and data access capabilities in IDL, Python, and Java. We also have quite a bit of work yet to do, including completion of the implementation of access to SDO EVE data, and access to some nineteen other data sets from space- and ground-based observatories. In addition, we have been developing a new graphic user interface that will enable the saving of user interface and search preferences. We solicit advice from the community input prioritizing our task list, and adding to it

Euro-VO-Coordination of virtual observatory activities in Europe

NASA Astrophysics Data System (ADS)

Genova, Françoise; Allen, Mark G.; Arviset, Christophe; Lawrence, Andy; Pasian, Fabio; Solano, Enrique; Wambsganss, Joachim

2015-06-01

The European Virtual Observatory Euro-VO has been coordinating European VO activities through a series of projects co-funded by the European Commission over the last 15 years. The bulk of VO work in Europe is ensured by the national VO initiatives and those of intergovernmental agencies. VO activities at the European level coordinate the work in support of the three "pillars" of the Virtual Observatory: support to the scientific community, take-up by the data providers, and technological activities. Several Euro-VO projects have also provided direct support to selected developments and prototyping. This paper explains the methodology used by Euro-VO over the years. It summarises the activities which were performed and their evolutions at different stages of the development of the VO, explains the Euro-VO role with respect to the international and national levels of VO activities, details the lessons learnt for best practices for the coordination of the VO building blocks, and the liaison with other European initiatives, documenting the added-value of European coordination. Finally, the current status and next steps of Euro-VO are briefly addressed.

Virtual Observatories for Space Physics Observations and Simulations: New Routes to Efficient Access and Visualization

NASA Technical Reports Server (NTRS)

Roberts, Aaron

2005-01-01

New tools for data access and visualization promise to make the analysis of space plasma data both more efficient and more powerful, especially for answering questions about the global structure and dynamics of the Sun-Earth system. We will show how new existing tools (particularly the Virtual Space Physics Observatory-VSPO-and the Visual System for Browsing, Analysis and Retrieval of Data-ViSBARD; look for the acronyms in Google) already provide rapid access to such information as spacecraft orbits, browse plots, and detailed data, as well as visualizations that can quickly unite our view of multispacecraft observations. We will show movies illustrating multispacecraft observations of the solar wind and magnetosphere during a magnetic storm, and of simulations of 3 0-spacecraft observations derived from MHD simulations of the magnetosphere sampled along likely trajectories of the spacecraft for the MagCon mission. An important issue remaining to be solved is how best to integrate simulation data and services into the Virtual Observatory environment, and this talk will hopefully stimulate further discussion along these lines.

The development, deployment, and impact of the virtual observatory, Part II

NASA Astrophysics Data System (ADS)

Hanisch, R. J.

2015-06-01

This is the second special issue of Astronomy and Computing devoted to the Virtual Observatory, and we again see a combination of papers covering various aspects of the VO, from infrastructure to applications to programmatics. The critical role of data models is described by Louys, and the method by which applications communicate amongst each other through the Simple Applications Messaging Protocol (SAMP) is described by Taylor et al. Demleitner et al. explain the client interfaces to the VO registry, that is, how applications developers can query the registry for information about VO-compliant data collections and services.1

Integrated Access to Heliospheric and Magnetospheric Data

NASA Astrophysics Data System (ADS)

Merka, J.; Szabo, A.; Narock, T. W.

2007-05-01

Heliospheric and magnetospheric data are provided by a variety of diverse sources. For space physics scientists, knowing that such data sources exist and where they are located are only the first hurdles to overcome before they can utilize the data for research. As a solution, the NASA Heliophysics Division has established a group of virtual observatories (VOs) to provide the scientific community with integrated access to well documented data and related services. The VOs are organized by scientific discipline and yet their essential characteristic is cross-discipline data discovery and exchange. In this talk, we will demonstrate the architecture and features of two distributed data systems, the Virtual Heliospheric Observatory (VHO) and the Virtual Magnetospheric Observatory at NASA Goddard Space Flight Center (VMO/G). The VHO and VMO/G are designed to share most of the components to facilitate faster development and to ease communication between the two VxOs. Since different communities are served by the two observatories, slightly, and sometimes even significantly, different terms and expectations must be accommodated and correctly processed. In our approach the interfaces are tuned for a particular community while the standard SPASE data model is employed internally. Together with other VxOs, we are also developing a standard query language for metadata exchange among the VxOs, data providers, and VxO-related services. Specific examples will be given. http:vho.nasa.gov

Analysis and Modeling of the Wavefield Generated by Explosions at the San Andreas Fault Observatory at Depth

DTIC Science & Technology

2010-09-01

method to ~ 4 Hz wave propagation using SAFOD borehole seismometers and the Parkfield Array Seismic Observatory (PASO) array (Thurber et al., 2004...limitations in mind, we apply our method to ~ 4 Hz wave propagation using SAFOD borehole seismometers and the Parkfield Array Seismic Observatory (PASO...Proposal No. BAA09-69 ABSTRACT Surface array and deep borehole recordings of chemical explosions in the near-source (0-20 km) region are studied to

Back to the future: virtualization of the computing environment at the W. M. Keck Observatory

NASA Astrophysics Data System (ADS)

McCann, Kevin L.; Birch, Denny A.; Holt, Jennifer M.; Randolph, William B.; Ward, Josephine A.

2014-07-01

Over its two decades of science operations, the W.M. Keck Observatory computing environment has evolved to contain a distributed hybrid mix of hundreds of servers, desktops and laptops of multiple different hardware platforms, O/S versions and vintages. Supporting the growing computing capabilities to meet the observatory's diverse, evolving computing demands within fixed budget constraints, presents many challenges. This paper describes the significant role that virtualization is playing in addressing these challenges while improving the level and quality of service as well as realizing significant savings across many cost areas. Starting in December 2012, the observatory embarked on an ambitious plan to incrementally test and deploy a migration to virtualized platforms to address a broad range of specific opportunities. Implementation to date has been surprisingly glitch free, progressing well and yielding tangible benefits much faster than many expected. We describe here the general approach, starting with the initial identification of some low hanging fruit which also provided opportunity to gain experience and build confidence among both the implementation team and the user community. We describe the range of challenges, opportunities and cost savings potential. Very significant among these was the substantial power savings which resulted in strong broad support for moving forward. We go on to describe the phasing plan, the evolving scalable architecture, some of the specific technical choices, as well as some of the individual technical issues encountered along the way. The phased implementation spans Windows and Unix servers for scientific, engineering and business operations, virtualized desktops for typical office users as well as more the more demanding graphics intensive CAD users. Other areas discussed in this paper include staff training, load balancing, redundancy, scalability, remote access, disaster readiness and recovery.

GAIA virtual observatory - development and practices

NASA Astrophysics Data System (ADS)

Syrjäsuo, Mikko; Marple, Steve

2010-05-01

The Global Auroral Imaging Access, or GAIA, is a virtual observatory providing quick access to summary data from satellite and ground-based instruments that remote sense auroral precipitation (http://gaia-vxo.org). This web-based service facilitates locating data relevant to particular events by simultaneously displaying summary images from various data sets around the world. At the moment, there are GAIA server nodes in Canada, Finland, Norway and the UK. The development is an international effort and the software and metadata are freely available. The GAIA system is based on a relational database which is queried by a dedicated software suite that also creates the graphical end-user interface if such is needed. Most commonly, the virtual observatory is used interactively by using a web browser: the user provides the date and the type of data of interest. As the summary data from multiple instruments are displayed simultaneously, the user can conveniently explore the recorded data. The virtual observatory provides essentially instant access to the images originating from all major auroral instrument networks including THEMIS, NORSTAR, GLORIA and MIRACLE. The scientific, educational and outreach use is limited by creativity rather than access. The first version of the GAIA was developed at the University of Calgary (Alberta, Canada) in 2004-2005. This proof-of-concept included mainly THEMIS and MIRACLE data, which comprised of millions of summary plots and thumbnail images. However, it was soon realised that a complete re-design was necessary to increase flexibility. In the presentation, we will discuss the early history and motivation of GAIA as well as how the development continued towards the current version. The emphasis will be on practical problems and their solutions. Relevant design choices will also be highlighted.

Improving Interstellar Medium Mitigation in Millisecond PulsarTiming Models for Gravitational Wave Detection Sensitivity

NASA Astrophysics Data System (ADS)

Wilson, Robert C.

2018-01-01

This study aims to increase the sensitivity of pulsar timing arrays (PTAs) used by astronomers ofthe North American Nanohertz Observatory for Gravitational Waves (NANOGrav) to detectgravitational waves (GWs). Millisecond pulsars with many epochs of observations will be used todetermine if dispersive, frequency-dependent pulse time-of-arrival (TOA) delays caused by theinterstellar medium (ISM) can be more accurately predicted over numerous frequency channels.This project will contribute to the ongoing work to detect low-frequency GWs using PTAs. Dataused for this study will be from both the 110m telescope at the Green Bank Observatory in WestVirginia and the 305m telescope at the Arecibo Observatory in Puerto Rico.

Virtual observatory tools and amateur radio observations supporting scientific analysis of Jupiter radio emissions

NASA Astrophysics Data System (ADS)

Cecconi, Baptiste; Hess, Sebastien; Le Sidaner, Pierre; Savalle, Renaud; Stéphane, Erard; Coffre, Andrée; Thétas, Emmanuel; André, Nicolas; Génot, Vincent; Thieman, Jim; Typinski, Dave; Sky, Jim; Higgins, Chuck; Imai, Masafumi

2016-04-01

In the frame of the preparation of the NASA/JUNO and ESA/JUICE (Jupiter Icy Moon Explorer) missions, and the development of a planetary sciences virtual observatory (VO), we are proposing a new set of tools directed to data providers as well as users, in order to ease data sharing and discovery. We will focus on ground based planetary radio observations (thus mainly Jupiter radio emissions), trying for instance to enhance the temporal coverage of jovian decametric emission. The data service we will be using is EPN-TAP, a planetary science data access protocol developed by Europlanet-VESPA (Virtual European Solar and Planetary Access). This protocol is derived from IVOA (International Virtual Observatory Alliance) standards. The Jupiter Routine Observations from the Nancay Decameter Array are already shared on the planetary science VO using this protocol, as well as data from the Iitate Low Frquency Radio Antenna, in Japan. Amateur radio data from the RadioJOVE project is also available. The attached figure shows data from those three providers. We will first introduce the VO tools and concepts of interest for the planetary radioastronomy community. We will then present the various data formats now used for such data services, as well as their associated metadata. We will finally show various prototypical tools that make use of this shared datasets.

Developing a Virtual Network of Research Observatories

NASA Astrophysics Data System (ADS)

Hooper, R. P.; Kirschtl, D.

2008-12-01

The hydrologic community has been discussing the concept of a network of observatories for the advancement of hydrologic science in areas of scaling processes, in testing generality of hypotheses, and in examining non-linear couplings between hydrologic, biotic, and human systems. The Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) is exploring the formation of a virtual network of observatories, formed from existing field studies without regard to funding source. Such a network would encourage sharing of data, metadata, field methods, and data analysis techniques to enable multidisciplinary synthesis, meta-analysis, and scientific collaboration in hydrologic and environmental science and engineering. The virtual network would strive to provide both the data and the environmental context of the data through advanced cyberinfrastructure support. The foundation for this virtual network is Water Data Services that enable the publication of time-series data collected at fixed points using a services-oriented architecture. These publication services, developed in the CUAHSI Hydrologic Information Systems project, permit the discovery of data from both academic and government sources through a single portal. Additional services under consideration are publication of geospatial data sets, immersive environments based upon site digital elevation models, and a common web portal to member sites populated with structured data about the site (such as land use history and geologic setting) to permit understanding the environmental context of the data being shared.

Gravitating toward Science: Parent-Child Interactions at a Gravitational-Wave Observatory

ERIC Educational Resources Information Center

Szechter, Lisa E.; Carey, Elizabeth J.

2009-01-01

This research examined the nature of parent-child conversations at an informal science education center housed in an active gravitational-wave observatory. Each of 20 parent-child dyads explored an interactive exhibit hall privately, without the distraction of other visitors. Parents employed a variety of strategies to support their children's…

Networking of Bibliographical Information: Lessons learned for the Virtual Observatory

NASA Astrophysics Data System (ADS)

Genova, Françoise; Egret, Daniel

Networking of bibliographic information is particularly remarkable in astronomy. On-line journals, the ADS bibliographic database, SIMBAD and NED are everyday tools for research, and provide easy navigation from one resource to another. Tables are published on line, in close collaboration with data centers. Recent new developments include the links between observatory archives and the ADS, as well as the large scale prototyping of object links between Astronomy and Astrophysics and SIMBAD, following those implemented a few years ago with New Astronomy and the International Bulletin of Variable stars . This networking has been made possible by close collaboration between the ADS, data centers such as the CDS and NED, and the journals, and this partnership being now extended to observatory archives. Simple, de facto exchange standards, like the bibcode to refer to a published paper, have been the key for building links and exchanging data. This partnership, in which practitioners from different disciplines agree to link their resources and to work together to define useful and usable standards, has produced a revolution in scientists' practice. It is an excellent model for the Virtual Observatory projects.

AstroCloud, a Cyber-Infrastructure for Astronomy Research: Overview

NASA Astrophysics Data System (ADS)

Cui, C.; Yu, C.; Xiao, J.; He, B.; Li, C.; Fan, D.; Wang, C.; Hong, Z.; Li, S.; Mi, L.; Wan, W.; Cao, Z.; Wang, J.; Yin, S.; Fan, Y.; Wang, J.

2015-09-01

AstroCloud is a cyber-Infrastructure for Astronomy Research initiated by Chinese Virtual Observatory (China-VO) under funding support from NDRC (National Development and Reform commission) and CAS (Chinese Academy of Sciences). Tasks such as proposal submission, proposal peer-review, data archiving, data quality control, data release and open access, Cloud based data processing and analyzing, will be all supported on the platform. It will act as a full lifecycle management system for astronomical data and telescopes. Achievements from international Virtual Observatories and Cloud Computing are adopted heavily. In this paper, backgrounds of the project, key features of the system, and latest progresses are introduced.

Identification and characterization of low-mass stars and brown dwarfs using Virtual Observatory tools.

NASA Astrophysics Data System (ADS)

Aberasturi, M.; Solano, E.; Martín, E.

2015-05-01

Low-mass stars and brown dwarfs (with spectral types M, L, T and Y) are the most common objects in the Milky Way. A complete census of these objects is necessary to understand the theories about their complex structure and formation processes. In order to increase the number of known objects in the Solar neighborhood (d<30 pc), we have made use of the Virtual Observatory which allows an efficient handling of the huge amount of information available in astronomical databases. We also used the WFC3 installed in the Hubble Space Telescope to look for T5+ dwarfs binaries.

ASCOT: A Collaborative Platform for the Virtual Observatory

NASA Astrophysics Data System (ADS)

Marcos, D.; Connolly, A. J.; Krughoff, K. S.; Smith, I.; Wallace, S. C.

2012-09-01

The digital networks are changing the way that knowledge is created, structured, curated, consumed, archived and referenced. Projects like Wikipedia, Github or Galaxy Zoo have shown the potential of online communities to develop and communicate ideas. ASCOT is a web based framework that facilitates collaboration among astronomers providing a simple way to share, explore, interact and analyze large amounts of data from a broad range of sources available trough the Virtual Observatories (VO). Designed with a strong emphasis on usability, ASCOT takes advantage of the latest generation of web standards and cloud technologies to implement an extendable and customizable stack of web tools and services.

ESO Advanced Data Products for the Virtual Observatory

NASA Astrophysics Data System (ADS)

Retzlaff, J.; Delmotte, N.; Rite, C.; Rosati, P.; Slijkhuis, R.; Vandame, B.

2006-07-01

Advanced Data Products, that is, completely reduced, fully characterized science-ready data sets, play a crucial role for the success of the Virtual Observatory as a whole. We report on on-going work at ESO towards the creation and publication of Advanced Data Products in compliance with present VO standards on resource metadata. The new deep NIR multi-color mosaic of the GOODS/CDF-S region is used to showcase different aspects of the entire process: data reduction employing our MVM-based reduction pipeline, calibration and data characterization procedures, standardization of metadata content, and, finally, a prospect of the scientific potential illustrated by new results on deep galaxy number counts.

A Security-façade Library for Virtual-observatory Software

NASA Astrophysics Data System (ADS)

Rixon, G.

2009-09-01

The security-façade library implements, for Java, IVOA's security standards. It supports the authentication mechanisms for SOAP and REST web-services, the sign-on mechanisms (with MyProxy, AstroGrid Accounts protocol or local credential-caches), the delegation protocol, and RFC3820-enabled HTTPS for Apache Tomcat. Using the façade, a developer who is not a security specialist can easily add access control to a virtual-observatory service and call secured services from an application. The library has been an internal part of AstroGrid software for some time and it is now offered for use by other developers.

Identification of binary and multiple systems in TGAS using the Virtual Observatory

NASA Astrophysics Data System (ADS)

Jiménez-Esteban, F.; Solano, E.

2018-04-01

Binary and multiple stars have long provided an effective method of testing stellar formation and evolution theories. In particular, wide binary systems with separations > 20,000 au are particularly challenging as their physical separations are beyond the typical size of a collapsing cloud core (5,000 - 10,000 au). We present here a preliminary work in which we make use of the TGAS catalogue and Virtual Observatory tools and services (Aladin, TOPCAT, STILTS, VOSA, VizieR) to identify binary and multiple star candidate systems. The catalogue will be available from the Spanish VO portal (http://svo.cab.inta-csic.es) in the coming months.

Extending Iris: The VAO SED Analysis Tool

NASA Astrophysics Data System (ADS)

Laurino, O.; Busko, I.; Cresitello-Dittmar, M.; D'Abrusco, R.; Doe, S.; Evans, J.; Pevunova, O.

2013-10-01

Iris is a tool developed by the Virtual Astronomical Observatory (VAO) for building and analyzing Spectral Energy Distributions (SEDs). Iris was designed to be extensible, so that new components and models can be developed by third parties and then included at runtime. Iris can be extended in different ways: new file readers allow users to integrate data in custom formats into Iris SEDs; new models can be fitted to the data, in the form of template libraries for template fitting, data tables, and arbitrary Python functions. The interoperability-centered design of Iris and the Virtual Observatory standards and protocols can enable new science functionalities involving SED data.

Promise and Progress of Millihertz Gravitational-Wave Astronomy

NASA Technical Reports Server (NTRS)

Baker, John G.

2017-01-01

Extending the new field of gravitational wave (GW) astronomy into the millihertz band with a space-based GW observatory is a high-priority objective of international astronomy community. This paper summarizes the astrophysical promise and the technological groundwork for such an observatory, concretely focusing on the prospects for the proposed Laser Interferometer Space Antenna (LISA) mission concept.

Creation of an instrument maintenance program at W. M. Keck Observatory

NASA Astrophysics Data System (ADS)

Hill, G. M.; Kwok, S. H.; Mader, J. A.; Wirth, G. D.; Dahm, S. E.; Goodrich, R. W.

2014-08-01

Until a few years ago, the W. M. Keck Observatory (WMKO) did not have a systematic program of instrument maintenance at a level appropriate for a world-leading observatory. We describe the creation of such a program within the context of WMKO's lean operations model which posed challenges but also guided the design of the system and resulted in some unique and notable capabilities. These capabilities and the flexibility of the system have led to its adoption across the Observatory for virtually all PM's. The success of the Observatory in implementing the program and its impact on instrument reliability are presented. Lessons learned are reviewed and strategic implications discussed.

Chicago's Dearborn Observatory: a study in survival

NASA Astrophysics Data System (ADS)

Bartky, Ian R.

2000-12-01

The Dearborn Observatory, located on the Old University of Chicago campus from 1863 until 1888, was America's most promising astronomical facility when it was founded. Established by the Chicago Astronomical Society and directed by one of the country's most gifted astronomers, it boasted the largest telescope in the world and virtually unlimited operating funds. The Great Chicago Fire of 1871 destroyed its funding and demolished its research programme. Only via the sale of time signals and the heroic efforts of two amateur astronomers did the Dearborn Observatory survive.

Observable tensor-to-scalar ratio and secondary gravitational wave background

NASA Astrophysics Data System (ADS)

Chatterjee, Arindam; Mazumdar, Anupam

2018-03-01

In this paper we will highlight how a simple vacuum energy dominated inflection-point inflation can match the current data from cosmic microwave background radiation, and predict large primordial tensor to scalar ratio, r ˜O (10-3-10-2), with observable second order gravitational wave background, which can be potentially detectable from future experiments, such as DECi-hertz Interferometer Gravitational wave Observatory (DECIGO), Laser Interferometer Space Antenna (eLISA), cosmic explorer (CE), and big bang observatory (BBO).

Virtual planets atlas 1.0 freeware

NASA Astrophysics Data System (ADS)

Legrand, C.; Chevalley, P.

2015-10-01

Since 2002, we develop the "Virtual Moon Atlas -http://www.ap-i.net/avl/en/start" a freeware to help Moon observing and to improve interest for Moon in general public. VMA freeware has been downloaded near 900000 times all over the world and is or has been used by several professional organizations such as Kitt Peak Observatory, National Japan Observatory, Birkbeck College / University College London (K. Joy), BBC Sky at night, several French astronomy magazines and astronomy writers (P. Harrington, S. French...) . Recommended by ESA, registered as educational software by French ministry for education, it has also yet been presented at 2006 & 2007 LPSC and PCC2 in 2011 We have declined this freeware in a new tool with the same goals, but for the telluric planets and satellites, the "Virtual Planets Atlas (VPA / http://www.ap-i.net/avp/en/start") now in version 1.0.

Report from the Gravitational Observatory Advisory Team

NASA Astrophysics Data System (ADS)

Mueller, Guido; Gravitational Observatory Advisory Team

2016-03-01

As a response to the selection of the Gravitational Universe as the science theme for ESA's L3 mission, ESA formed the Gravitational-Wave Observatory Advisory Team (GOAT) to advise ESA on the scientific and technological approach for a gravitational wave observatory. NASA is participating with three US scientists and one NASA observer; JAXA was also invited and participates with one observer. The GOAT looked at a range of mission technologies and designs, discussed their technical readiness with respect to the ESA schedule, recommended technology development activities for selected technologies, and worked with the wider gravitational-wave community to analyze the impact on the science of the various mission designs. The final report is expected to be submitted to ESA early March and I plan to summarize its content.

VESPA: A community-driven Virtual Observatory in Planetary Science

NASA Astrophysics Data System (ADS)

Erard, S.; Cecconi, B.; Le Sidaner, P.; Rossi, A. P.; Capria, M. T.; Schmitt, B.; Génot, V.; André, N.; Vandaele, A. C.; Scherf, M.; Hueso, R.; Määttänen, A.; Thuillot, W.; Carry, B.; Achilleos, N.; Marmo, C.; Santolik, O.; Benson, K.; Fernique, P.; Beigbeder, L.; Millour, E.; Rousseau, B.; Andrieu, F.; Chauvin, C.; Minin, M.; Ivanoski, S.; Longobardo, A.; Bollard, P.; Albert, D.; Gangloff, M.; Jourdane, N.; Bouchemit, M.; Glorian, J.-M.; Trompet, L.; Al-Ubaidi, T.; Juaristi, J.; Desmars, J.; Guio, P.; Delaa, O.; Lagain, A.; Soucek, J.; Pisa, D.

2018-01-01

The VESPA data access system focuses on applying Virtual Observatory (VO) standards and tools to Planetary Science. Building on a previous EC-funded Europlanet program, it has reached maturity during the first year of a new Europlanet 2020 program (started in 2015 for 4 years). The infrastructure has been upgraded to handle many fields of Solar System studies, with a focus both on users and data providers. This paper describes the broad lines of the current VESPA infrastructure as seen by a potential user, and provides examples of real use cases in several thematic areas. These use cases are also intended to identify hints for future developments and adaptations of VO tools to Planetary Science.

VisIVO: A Tool for the Virtual Observatory and Grid Environment

NASA Astrophysics Data System (ADS)

Becciani, U.; Comparato, M.; Costa, A.; Larsson, B.; Gheller, C.; Pasian, F.; Smareglia, R.

2007-10-01

We present the new features of VisIVO, software for the visualization and analysis of astrophysical data which can be retrieved from the Virtual Observatory framework and used for cosmological simulations running both on Windows and GNU/Linux platforms. VisIVO is VO standards compliant and supports the most important astronomical data formats such as FITS, HDF5 and VOTables. It is free software and can be downloaded from the web site http://visivo.cineca.it. VisIVO can interoperate with other astronomical VO compliant tools through PLASTIC (PLatform for AStronomical Tool InterConnection). This feature allows VisIVO to share data with many other astronomical packages to further analyze the loaded data.

VO-compliant libraries of high resolution spectra of cool stars

NASA Astrophysics Data System (ADS)

Montes, D.

2008-10-01

In this contribution we describe a Virtual Observatory (VO) compliant version of the libraries of high resolution spectra of cool stars described by Montes et al. (1997; 1998; and 1999). Since their publication the fully reduced spectra in FITS format have been available via ftp and in the World Wide Web. However, in the VO all the spectra will be accessible using a common web interface following the standards of the International Virtual Observatory Alliance (IVOA). These libraries include F, G, K and M field stars, from dwarfs to giants. The spectral coverage is from 3800 to 10000 Å, with spectral resolution ranging from 0.09 to 3.0 Å.

Geographic and Annual Influences on Optical Follow-up of Gravitational Wave Events

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, Varun; Bhalerao, Varun; Bose, Sukanta

2017-03-20

We investigate the effects of observatory location on the probability of discovering optical/infrared (OIR) counterparts of gravitational wave sources. We show that, for the LIGO–Virgo network, the odds of discovering OIR counterparts show some latitude dependence. A stronger effect is seen to arise from the timing of LIGO–Virgo observing runs during the year, with northern OIR observatories having a better chance of finding the counterparts in northern winters. Assuming identical technical capabilities, the tentative mid-2017 three-detector network observing run favors southern OIR observatories for the discovery of electromagnetic counterparts.

A Virtual Field Trip to the Gemini Observatory

NASA Astrophysics Data System (ADS)

Fisher, R. Scott; Michaud, P. D.

2010-01-01

Live from Gemini (LfG) is a virtual field trip using video conferencing technology to connect primary, secondary and post-secondary students with scientists and educators at the Gemini Observatory. As a pilot project, LfG is rapidly becoming one of the observatory's most often-requested educational programs for learners of all ages. The program aligns exceptionally well with national science (and technology) standards, as well as existing school curricula. This combination makes it easy for teachers to justify participation in the program, especially as the necessary video conferencing technology becomes ever more ubiquitous in classrooms and technology learning centers around the world. In developing and testing this pilot project, a programmatic approach and philosophy evolved that includes post-field-trip educational materials, multi-disciplinary subject matter (astronomy, geology, mathematics, meteorology, engineering and even language - the program is offered in Spanish from Gemini South in Chile), and the establishment of a personal connection and rapport with students. The presenters work to create a comfortable interaction despite the perceived technological barriers. The authors’ experiences with the LfG pilot project convince us that this model is viable for almost any astronomical observatory and should be considered by any dynamic, technology- and education-oriented facility.

Building a Virtual Solar Observatory: I Look Around and There's a Petabyte Following Me

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Bogart, R.; Hill. F.; Martens, P.; Oergerle, William (Technical Monitor)

2002-01-01

The 2001 July NASA Senior Review of Sun-Earth Connections missions and data centers directed the Solar Data Analysis Center (SDAC) to proceed in studying and implementing a Virtual Solar Observatory (VSO) to ease the identification of and access to distributed archives of solar data. Any such design (cf. the National Virtual Observatory and NASA's Planetary Data System) consists of three elements: the distributed archives, a "broker" facility that translates metadata from all partner archives into a single standard for searches, and a user interface to allow searching, browsing, and download of data. Three groups are now engaged in a six-month study that will produce a candidate design and implementation roadmap for the VSO. We hope to proceed with the construction of a prototype VSO in US fiscal year 2003, with fuller deployment dependent on community reaction to and use of the capability. We therefore invite as broad as possible public comment and involvement, and invite interested parties to a "birds of a feather" session at this meeting. VSO is partnered with the European Grid of Solar Observations (EGSO), and if successful, we hope to be able to offer the VSO as the basis for the solar component of a Living With a Star data system.

VirtualSpace: A vision of a machine-learned virtual space environment

NASA Astrophysics Data System (ADS)

Bortnik, J.; Sarno-Smith, L. K.; Chu, X.; Li, W.; Ma, Q.; Angelopoulos, V.; Thorne, R. M.

2017-12-01

Space borne instrumentation tends to come and go. A typical instrument will go through a phase of design and construction, be deployed on a spacecraft for several years while it collects data, and then be decommissioned and fade into obscurity. The data collected from that instrument will typically receive much attention while it is being collected, perhaps in the form of event studies, conjunctions with other instruments, or a few statistical surveys, but once the instrument or spacecraft is decommissioned, the data will be archived and receive progressively less attention with every passing year. This is the fate of all historical data, and will be the fate of data being collected by instruments even at the present time. But what if those instruments could come alive, and all be simultaneously present at any and every point in time and space? Imagine the scientific insights, and societal gains that could be achieved with a grand (virtual) heliophysical observatory that consists of every current and historical mission ever deployed? We propose that this is not just fantasy but is imminently doable with the data currently available, with the present computational resources, and with currently available algorithms. This project revitalizes existing data resources and lays the groundwork for incorporating data from every future mission to expand the scope and refine the resolution of the virtual observatory. We call this project VirtualSpace: a machine-learned virtual space environment.

Progress and Prospects toward a Space-based Gravitational-Wave Observatory

NASA Technical Reports Server (NTRS)

Baker, John

2012-01-01

Over the last few years there has been much activity in the effort to produce a space-based gravitational-wave observatory. These efforts have enriched the understanding of the scientific capabilities of such an observatory leading to broad recognition of its value as an astronomical instrument. At the same time, rapidly developing events in the US and Europe have lead to a more complicated outlook than the baseline Laser Interferometer Space Antenna (LISA) project plan of a few years ago. I will discuss recent progress and developments resulting from the European eLISA study and the SGO study in the US and prospects looking forward.

GW170814: A three-detector observation of gravitational waves from a binary black hole coalescence

NASA Astrophysics Data System (ADS)

Lange, Jacob; LIGO-Virgo Collaboration

2018-01-01

The fourth gravitational wave detection was observed on the 14th of August 2017 announced on the 27th of September 2017. While LIGO observatories again contributed, this was the first detection that included data from the Virgo observatory in Pisa, Italy. The inferred masses of the initial black holes are 30.5 and 25.3 at the 90% credible level. The luminosity distance of the source is 540 Mpc, corresponding to a redshift of z = 0.11. Due to the addition of the third observatory, the sky localization of the source is improved from a 1160 square degrees to 60 square degrees.

A virtual reality environment for telescope operation

NASA Astrophysics Data System (ADS)

Martínez, Luis A.; Villarreal, José L.; Ángeles, Fernando; Bernal, Abel

2010-07-01

Astronomical observatories and telescopes are becoming increasingly large and complex systems, demanding to any potential user the acquirement of great amount of information previous to access them. At present, the most common way to overcome that information is through the implementation of larger graphical user interfaces and computer monitors to increase the display area. Tonantzintla Observatory has a 1-m telescope with a remote observing system. As a step forward in the improvement of the telescope software, we have designed a Virtual Reality (VR) environment that works as an extension of the remote system and allows us to operate the telescope. In this work we explore this alternative technology that is being suggested here as a software platform for the operation of the 1-m telescope.

Overview of Virtual Observatory Tools

NASA Astrophysics Data System (ADS)

Allen, M. G.

2009-07-01

I provide a brief introduction and tour of selected Virtual Observatory tools to highlight some of the core functions provided by the VO, and the way that astronomers may use the tools and services for doing science. VO tools provide advanced functions for searching and using images, catalogues and spectra that have been made available in the VO. The tools may work together by providing efficient and innovative browsing and analysis of data, and I also describe how many VO services may be accessed by a scripting or command line environment. Early science usage of the VO provides important feedback on the development of the system, and I show how VO portals try to address early user comments about the navigation and use of the VO.

The Virtual Solar-Terrestrial Observatory; access to and use of diverse solar and solar- terrestrial data.

NASA Astrophysics Data System (ADS)

Fox, P.; McGuinness, D.; Cinquini, L.; West, P.; Garcia, J.; Zednik, S.; Benedict, J.

2008-05-01

This presentation will demonstrate how users and other data providers can utilize the Virtual Solar-Terrestrial Observatory (VSTO) to find, access and use diverse data holdings from the disciplines of solar, solar-terrestrial and space physics. VSTO provides a web portal, web services and a native applications programming interface for various levels of users. Since these access methods are based on semantic web technologies and refer to the VSTO ontology, users also have the option of taking advantage of value added services when accessing and using the data. We present example of both conventional use of VSTO as well as the advanced semantics use. Finally, we present our future directions for VSTO and semantic data frameworks in general.

The Virtual Solar-Terrestrial Observatory; access to and use of diverse solar and solar-terrestrial data

NASA Astrophysics Data System (ADS)

Fox, P.

2007-05-01

This presentation will demonstrate how users and other data providers can utilize the Virtual Solar-Terrestrial Observatory (VSTO) to find, access and use diverse data holdings from the disciplines of solar, solar-terrestrial and space physics. VSTO provides a web portal, web services and a native applications programming interface for various levels of users. Since these access methods are based on semantic web technologies and refer to the VSTO ontology, users also have the option of taking advantage of value added services when accessing and using the data. We present example of both conventional use of VSTO as well as the advanced semantics use. Finally, we present our future directions for VSTO and semantic data frameworks in general.

LIGO - The Laser Interferometer Gravitational-Wave Observatory

NASA Technical Reports Server (NTRS)

Abramovici, Alex; Althouse, William E.; Drever, Ronald W. P.; Gursel, Yekta; Kawamura, Seiji; Raab, Frederick J.; Shoemaker, David; Sievers, Lisa; Spero, Robert E.; Thorne, Kip S.

1992-01-01

The goal of the Laser Interferometer Gravitational-Wave Observatory (LIGO) Project is to detect and study astrophysical gravitational waves and use data from them for research in physics and astronomy. LIGO will support studies concerning the nature and nonlinear dynamics for gravity, the structures of black holes, and the equation of state of nuclear matter. It will also measure the masses, birth rates, collisions, and distributions of black holes and neutron stars in the universe and probe the cores of supernovae and the very early universe. The technology for LIGO has been developed during the past 20 years. Construction will begin in 1992, and under the present schedule, LIGO's gravitational-wave searches will begin in 1998.

Wave field synthesis of moving virtual sound sources with complex radiation properties.

PubMed

Ahrens, Jens; Spors, Sascha

2011-11-01

An approach to the synthesis of moving virtual sound sources with complex radiation properties in wave field synthesis is presented. The approach exploits the fact that any stationary sound source of finite spatial extent radiates spherical waves at sufficient distance. The angular dependency of the radiation properties of the source under consideration is reflected by the amplitude and phase distribution on the spherical wave fronts. The sound field emitted by a uniformly moving monopole source is derived and the far-field radiation properties of the complex virtual source under consideration are incorporated in order to derive a closed-form expression for the loudspeaker driving signal. The results are illustrated via numerical simulations of the synthesis of the sound field of a sample moving complex virtual source.

Integrating a Data Center and Resident Archive into the Emerging Virtual Observatiry System: Practical experience and perspectives

NASA Astrophysics Data System (ADS)

Davis, A. J.; Kanekal, S. G.; Looper, M. D.; Mason, G. M.; Mewaldt, R. A.

2006-12-01

The SAMPEX Resident Archive is currently under construction, and will be co-hosted at Caltech with the ACE Science Center. With SAMPEX in low earth orbit, and ACE at L1, and a suite of instruments on each spacecraft, the combined data cover a very broad range in species, energy, location, and time. The data include solar wind, solar energetic particle, and galactic cosmic ray intensity and composition data, as well as solar wind and magnetic field parameters on a variety of time scales. We describe our recent efforts to provide enhanced access to these data via the emerging virtual observatory system, including work with the Space Physics Archive Search and Extract (SPASE) Consortium to ensure that the ACE and SAMPEX data can be adequately described using the SPASE data model, development of a SOAP web services interface between the ACE Science Center and the virtual observatories, and ideas for combining the ACE and SAMPEx data in useful ways.

The Virtual Observatory Powered PhD Thesis

NASA Astrophysics Data System (ADS)

Zolotukhin, I. Yu.

2010-12-01

The Virtual Observatory has reached sufficient maturity for its routine scientific exploitation by astronomers. To prove this statement, here I present a brief description of the complete VO-powered PhD thesis entitled “Galactic and extragalactic research with modern surveys and the Virtual Observatory” comprising 4 science cases covering various aspects of astrophysical research. These comprize: (1) homogeneous search and measurement of main physical parameters of Galactic open star clusters in huge multi-band photometric surveys; (2) study of optical-to-NIR galaxy colors using a large homogeneous dataset including spectroscopy and photometry from SDSS and UKIDSS; (3) study of faint low-mass X-ray binary population in modern observational archives; (4) search for optical counterparts of unidentified X-ray objects with large positional uncertainties in the Galactic Plane. All these projects make heavy use of the VO technologies and tools and would not be achievable without them. So refereed papers published in the frame of this thesis can undoubtedly be added to the growing list of VO-based research works.

Solar eclipses at high latitudes: ionospheric effects in the lower ionosphere

NASA Astrophysics Data System (ADS)

Cherniakov, S.

2017-12-01

The partial reflection facility of the Polar Geophysical Institute (the Tumanny observatory, 69.0N, 35.7E) has observed behavior of the high-latitude lower ionosphere during the 20 March 2015 total solar eclipse. There were several effects during the eclipse. At the heights of 60-80 km the ionosphere has shown the effect of a "short night", but at the higher altitudes local enhanced electron concentration had a wave-like form. Data received by the riometer of the Tumanny observatory have also shown wave-like behavior. The behavior can be explained by influence of acoustic-gravity waves which originated after cooling of the atmosphere during the lunar shadow supersonic movement, and transport processes during the eclipse. During the 21 August 2017 solar eclipse there was a substorm at the high latitudes. But after the end of the substorm in the region of the Tumanny observatory the observed amplitudes of the reflected waves had wave effects which could be connected with the coming waves from the region of the eclipse. The wave features were also shown in the behavior of the total electron content (TEC) of the lower ionosphere. During several solar eclipses it was implemented observations of lower ionosphere behavior by the partial reflection facility of the Tumanny observatory. The consideration of the lower ionosphere TEC had revealed common features in the TEC behavior during the eclipses. The photochemical theory of processes in the lower ionosphere is very complicated and up to now it is not completely developed. Therefore introduction of the effective coefficients determining the total speed of several important reactions has been widely adopted when modeling the D-region of the ionosphere. However, experimental opportunities for obtaining effective recombination coefficients are rather limited. One of the methods to estimate effective recombination coefficients uses the phenomenon of a solar eclipse. During solar eclipses at the partial reflection facility of the Tumanny observatory observations were carried out. It gave possibility to obtain the behavior of the electron concentration in time at the selected heights. Using the obtained experimental profiles, the effective recombination coefficients at the D-region heights of the ionosphere have been evaluated.

A gravitational wave observatory operating beyond the quantum shot-noise limit

NASA Astrophysics Data System (ADS)

Ligo Scientific Collaboration; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M.; Adams, C.; Adhikari, R.; Affeldt, C.; Allen, B.; Allen, G. S.; Amador Ceron, E.; Amariutei, D.; Amin, R. S.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Arain, M. A.; Araya, M. C.; Aston, S. M.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P.; Ballmer, S.; Barker, D.; Barr, B.; Barriga, P.; Barsotti, L.; Barton, M. A.; Bartos, I.; Bassiri, R.; Bastarrika, M.; Batch, J.; Bauchrowitz, J.; Behnke, B.; Bell, A. S.; Belopolski, I.; Benacquista, M.; Berliner, J. M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biswas, R.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bondarescu, R.; Bork, R.; Born, M.; Bose, S.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Breyer, J.; Bridges, D. O.; Brinkmann, M.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brummitt, A.; Buonanno, A.; Burguet-Castell, J.; Burmeister, O.; Byer, R. L.; Cadonati, L.; Camp, J. B.; Campsie, P.; Cannizzo, J.; Cannon, K.; Cao, J.; Capano, C. D.; Caride, S.; Caudill, S.; Cavagliá, M.; Cepeda, C.; Chalermsongsak, T.; Chalkley, E.; Charlton, P.; Chelkowski, S.; Chen, Y.; Christensen, N.; Cho, H.; Chua, S. S. Y.; Chung, S.; Chung, C. T. Y.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J.; Clayton, J. H.; Conte, R.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M.; Couvares, P.; Coward, D. M.; Coyne, D. C.; Creighton, J. D. E.; Creighton, T. D.; Cruise, A. M.; Cumming, A.; Cunningham, L.; Cutler, R. M.; Dahl, K.; Danilishin, S. L.; Dannenberg, R.; Danzmann, K.; Daudert, B.; Daveloza, H.; Davies, G.; Daw, E. J.; Dayanga, T.; Debra, D.; Degallaix, J.; Dent, T.; Dergachev, V.; Derosa, R.; Desalvo, R.; Dhurandhar, S.; Diguglielmo, J.; di Palma, I.; Díaz, M.; Donovan, F.; Dooley, K. L.; Dorsher, S.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edgar, M.; Edwards, M.; Effler, A.; Ehrens, P.; Engel, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fairhurst, S.; Fan, Y.; Farr, B. F.; Farr, W.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Finn, L. S.; Fisher, R. P.; Flanigan, M.; Foley, S.; Forsi, E.; Fotopoulos, N.; Frede, M.; Frei, M.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fulda, P. J.; Fyffe, M.; Ganija, M. R.; Garcia, J.; Garofoli, J. A.; Geng, R.; Gergely, L. Á.; Gholami, I.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Gill, C.; Goetz, E.; Goggin, L. M.; González, G.; Gorodetsky, M. L.; Goßler, S.; Graef, C.; Grant, A.; Gras, S.; Gray, C.; Gray, N.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grosso, R.; Grote, H.; Grunewald, S.; Guido, C.; Gupta, R.; Gustafson, E. K.; Gustafson, R.; Ha, T.; Hage, B.; Hallam, J. M.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Heefner, J.; Heintze, M. C.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Herrera, V.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Hong, T.; Hooper, S.; Hosken, D. J.; Hough, J.; Howell, E. J.; Hughey, B.; Huynh-Dinh, T.; Husa, S.; Huttner, S. H.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Izumi, K.; Jacobson, M.; Jang, H.; Johnson, W. W.; Jones, D. I.; Jones, G.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kamaretsos, I.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Kells, W.; Keppel, D. G.; Keresztes, Z.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, B.; Kim, C.; Kim, D.; Kim, H.; Kim, K.; Kim, N.; Kim, Y.-M.; King, P. J.; Kinsey, M.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kokeyama, K.; Kondrashov, V.; Kopparapu, R.; Koranda, S.; Korth, W. Z.; Kozak, D.; Kringel, V.; Krishnamurthy, S.; Krishnan, B.; Kuehn, G.; Kumar, R.; Kwee, P.; Lam, P. K.; Landry, M.; Lang, M.; Lantz, B.; Lastzka, N.; Lawrie, C.; Lazzarini, A.; Leaci, P.; Lee, C. H.; Lee, H. M.; Leindecker, N.; Leong, J. R.; Leonor, I.; Li, J.; Lindquist, P. E.; Lockerbie, N. A.; Lodhia, D.; Lormand, M.; Luan, J.; Lubinski, M.; Lück, H.; Lundgren, A. P.; MacDonald, E.; Machenschalk, B.; Macinnis, M.; MacLeod, D. M.; Mageswaran, M.; Mailand, K.; Mandel, I.; Mandic, V.; Marandi, A.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Martin, I. W.; Martin, R. M.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McIver, J.; McKechan, D. J. A.; Meadors, G. D.; Mehmet, M.; Meier, T.; Melatos, A.; Melissinos, A. C.; Mendell, G.; Menendez, D.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Miller, J.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Moe, B.; Moesta, P.; Mohanty, S. D.; Moraru, D.; Moreno, G.; Mori, T.; Mossavi, K.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Müller-Ebhardt, H.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nash, T.; Nawrodt, R.; Necula, V.; Nelson, J.; Newton, G.; Nishizawa, A.; Nolting, D.; Nuttall, L.; O'Dell, J.; O'Reilly, B.; O'Shaughnessy, R.; Ochsner, E.; Oelker, E.; Oh, J. J.; Oh, S. H.; Ogin, G. H.; Oldenburg, R. G.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Page, A.; Pan, Y.; Pankow, C.; Papa, M. A.; Ajith, P.; Patel, P.; Pedraza, M.; Peiris, P.; Pekowsky, L.; Penn, S.; Peralta, C.; Perreca, A.; Phelps, M.; Pickenpack, M.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Plissi, M. V.; Pöld, J.; Postiglione, F.; Predoi, V.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prokhorov, L.; Puncken, O.; Quetschke, V.; Raab, F. J.; Radkins, H.; Raffai, P.; Rakhmanov, M.; Ramet, C. R.; Rankins, B.; Mohapatra, S. R. P.; Raymond, V.; Redwine, K.; Reed, C. M.; Reed, T.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Robertson, N. A.; Robinson, C.; Robinson, E. L.; Roddy, S.; Rodriguez, C.; Rodruck, M.; Rollins, J.; Romano, J. D.; Romie, J. H.; Röver, C.; Rowan, S.; Rüdiger, A.; Ryan, K.; Ryll, H.; Sainathan, P.; Sakosky, M.; Salemi, F.; Samblowski, A.; Sammut, L.; Sancho de La Jordana, L.; Sandberg, V.; Sankar, S.; Sannibale, V.; Santamaría, L.; Santiago-Prieto, I.; Santostasi, G.; Sathyaprakash, B. S.; Sato, S.; Saulson, P. R.; Savage, R. L.; Schilling, R.; Schlamminger, S.; Schnabel, R.; Schofield, R. M. S.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Searle, A. C.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sergeev, A.; Shaddock, D. A.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sibley, A.; Siemens, X.; Sigg, D.; Singer, A.; Singer, L.; Sintes, A. M.; Skelton, G.; Slagmolen, B. J. J.; Slutsky, J.; Smith, R. J. E.; Smith, J. R.; Smith, M. R.; Smith, N. D.; Somiya, K.; Sorazu, B.; Soto, J.; Speirits, F. C.; Stein, A. J.; Steinert, E.; Steinlechner, J.; Steinlechner, S.; Steplewski, S.; Stefszky, M.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S.; Stroeer, A. S.; Stuver, A. L.; Summerscales, T. Z.; Sung, M.; Susmithan, S.; Sutton, P. J.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, J. R.; Taylor, R.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Thüring, A.; Titsler, C.; Tokmakov, K. V.; Torres, C.; Torrie, C. I.; Traylor, G.; Trias, M.; Tseng, K.; Ugolini, D.; Urbanek, K.; Vahlbruch, H.; Vallisneri, M.; van Veggel, A. A.; Vass, S.; Vaulin, R.; Vecchio, A.; Veitch, J.; Veitch, P. J.; Veltkamp, C.; Villar, A. E.; Vitale, S.; Vorvick, C.; Vyatchanin, S. P.; Wade, A.; Waldman, S. J.; Wallace, L.; Wan, Y.; Wanner, A.; Wang, X.; Wang, Z.; Ward, R. L.; Wei, P.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wen, S.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D.; Whiting, B. F.; Wilkinson, C.; Willems, P. A.; Williams, H. R.; Williams, L.; Willke, B.; Winkelmann, L.; Winkler, W.; Wipf, C. C.; Wittel, H.; Wiseman, A. G.; Woan, G.; Wooley, R.; Worden, J.; Yablon, J.; Yakushin, I.; Yamamoto, K.; Yamamoto, H.; Yang, H.; Yeaton-Massey, D.; Yoshida, S.; Yu, P.; Zanolin, M.; Zhang, L.; Zhang, W.; Zhang, Z.; Zhao, C.; Zotov, N.; Zucker, M. E.; Zweizig, J.

2011-12-01

Around the globe several observatories are seeking the first direct detection of gravitational waves (GWs). These waves are predicted by Einstein's general theory of relativity and are generated, for example, by black-hole binary systems. Present GW detectors are Michelson-type kilometre-scale laser interferometers measuring the distance changes between mirrors suspended in vacuum. The sensitivity of these detectors at frequencies above several hundred hertz is limited by the vacuum (zero-point) fluctuations of the electromagnetic field. A quantum technology--the injection of squeezed light--offers a solution to this problem. Here we demonstrate the squeezed-light enhancement of GEO600, which will be the GW observatory operated by the LIGO Scientific Collaboration in its search for GWs for the next 3-4 years. GEO600 now operates with its best ever sensitivity, which proves the usefulness of quantum entanglement and the qualification of squeezed light as a key technology for future GW astronomy.

Iris: Constructing and Analyzing Spectral Energy Distributions with the Virtual Observatory

NASA Astrophysics Data System (ADS)

Laurino, O.; Budynkiewicz, J.; Busko, I.; Cresitello-Dittmar, M.; D'Abrusco, R.; Doe, S.; Evans, J.; Pevunova, O.

2014-05-01

We present Iris 2.0, the latest release of the Virtual Astronomical Observatory application for building and analyzing Spectral Energy Distributions (SEDs). With Iris, users may read in and display SEDs inspect and edit any selection of SED data, fit models to SEDs in arbitrary spectral ranges, and calculate confidence limits on best-fit parameters. SED data may be loaded into the application from VOTable and FITS files compliant with the International Virtual Observatoy Alliance interoperable data models, or retrieved directly from NED or the Italian Space Agency Science Data Center; data in non-standard formats may also be converted within the application. Users may seamlessy exchange data between Iris and other Virtual Observatoy tools using the Simple Application Messaging Protocol. Iris 2.0 also provides a tool for redshifting, interpolating, and measuring integratd fluxes, and allows simple aperture corrections for individual points and SED segments. Custom Python functions, template models and template libraries may be imported into Iris for fitting SEDs. Iris may be extended through Java plugins; users can install third-party packages, or develop their own plugin using Iris' Software Development Kit. Iris 2.0 is available for Linux and Mac OS X systems.

Surface wave inversion of central Texas quarry blasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bonner, J.L.; Goforth, T.T.

1993-02-01

Compressional and shear wave models of the upper crust in central Texas were obtained by inverting Rayleigh and Love waves recorded at the new W.M. Keck Foundation Seismological Observatory at Baylor University. The Keck Observatory, which became operational in April 1992, consists of a three-component, broadband Geotech seismometer located at a depth of 130 feet in a borehole 17 miles from the Baylor campus. The field station is solar powered, and the 140-dB dynamic range digital data are transmitted to the Baylor analysis lab via radio, where they are analyzed and archived. Limestone quarries located in all directions from themore » Keck Observatory detonate two to four tons of explosives per blast several times a week. Recordings of these blasts show sharp onsets of P and S waves, as well as dispersed Rayleigh and Love waves in the period band 1 to 3 seconds. Multiple filter analysis and phase matched filtering techniques were used to obtain high quality dispersion curves for the surface waves, and inversion techniques were applied to produce shear velocity models of the upper crust. A rapid increase in shear velocity at a depth of about 1.5 km is associated with the Ouachita Overthrust Belt. Portable seismic recording systems were placed at the quarries to monitor start times and initial wave forms. These data were combined with the Keck recordings to produce attenuation and compressional velocity models.« less

SPASE, Metadata, and the Heliophysics Virtual Observatories

NASA Technical Reports Server (NTRS)

Thieman, James; King, Todd; Roberts, Aaron

2010-01-01

To provide data search and access capability in the field of Heliophysics (the study of the Sun and its effects on the Solar System, especially the Earth) a number of Virtual Observatories (VO) have been established both via direct funding from the U.S. National Aeronautics and Space Administration (NASA) and through other funding agencies in the U.S. and worldwide. At least 15 systems can be labeled as Virtual Observatories in the Heliophysics community, 9 of them funded by NASA. The problem is that different metadata and data search approaches are used by these VO's and a search for data relevant to a particular research question can involve consulting with multiple VO's - needing to learn a different approach for finding and acquiring data for each. The Space Physics Archive Search and Extract (SPASE) project is intended to provide a common data model for Heliophysics data and therefore a common set of metadata for searches of the VO's. The SPASE Data Model has been developed through the common efforts of the Heliophysics Data and Model Consortium (HDMC) representatives over a number of years. We currently have released Version 2.1 of the Data Model. The advantages and disadvantages of the Data Model will be discussed along with the plans for the future. Recent changes requested by new members of the SPASE community indicate some of the directions for further development.

Recent Evolution of the CDS Services - SIMBAD, VizieR and Aladin

NASA Astrophysics Data System (ADS)

Genova, F.; Allen, M. G.; Bienayme, O.; Boch, T.; Bonnarel, F.; Cambresy, L.; Derriere, S.; Dubois, P.; Fernique, P.; Lesteven, S.; Loup, C.; Ochsenbein, F.; Schaaff, A.; Vollmer, B.; Wenger, M.; Louys, M.; Jasniewicz, G.; Davoust, E.

2005-12-01

The Centre de Donnees astronomiques de Strasbourg (CDS) maintains several widely used databases and services. Among significant recent evolutions: - a new version of SIMBAD (SIMBAD 4), based on the PostgreSQL database system, has been developed, to replace the current version which has been operational since 1990. It allows new query and sampling possibilities. For accessing SIMBAD from other applications, a full Web Service will be made available in addition to the client-server program which is presently used as name resolver by many services. - VizieR, which gives access to major surveys, observation logs and tables published in journals, is continuously updated in collaboration with journals and ground- and space-based observatories. The diversity of information in VizieR makes it an excellent test-bed for the Virtual Observatory, in particular for the definition of astronomy semantics and of query language, and the implementation of registries. - a major update of Aladin (Aladin V3 Multiview) was released in April 2005. It integrates in particular a multiview display, image resampling, blinking, access to real pixel values (not only 8 bits), compatibility with common image formats such as GIF, JPEG and PNG, scaling functions for better pixel contrasts, a 'Region of Interest Generator' which automatically builds small views around catalog objects, a cross-match function, the possibility to compute new catalog colums via algebraic expressions, extended script commands for batch mode use, and access to additional data such as SDSS. Aladin is routinely used as a portal to the Virtual Observatory. Many of the new functions have been prototyped in the frame of the European Astrophysical Virtual Observatory project, and other are tested for the VO-TECH project.

Enhanced sensitivity of the LIGO gravitational wave detector by using squeezed states of light

NASA Astrophysics Data System (ADS)

Aasi, J.; Abadie, J.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Affeldt, C.; Aguiar, O. D.; Ajith, P.; Allen, B.; Amador Ceron, E.; Amariutei, D.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C.; Ast, S.; Aston, S. M.; Atkinson, D.; Aufmuth, P.; Aulbert, C.; Austin, L.; Aylott, B. E.; Babak, S.; Baker, P. T.; Ballmer, S.; Bao, Y.; Barayoga, J. C.; Barker, D.; Barr, B.; Barsotti, L.; Barton, M. A.; Bartos, I.; Bassiri, R.; Batch, J.; Bauchrowitz, J.; Behnke, B.; Bell, A. S.; Bell, C.; Bergmann, G.; Berliner, J. M.; Bertolini, A.; Betzwieser, J.; Beveridge, N.; Beyersdorf, P. T.; Bhadbhade, T.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biscans, S.; Black, E.; Blackburn, J. K.; Blackburn, L.; Blair, D.; Bland, B.; Bock, O.; Bodiya, T. P.; Bogan, C.; Bond, C.; Bork, R.; Born, M.; Bose, S.; Bowers, J.; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Breyer, J.; Bridges, D. O.; Brinkmann, M.; Britzger, M.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Buckland, K.; Brückner, F.; Buchler, B. C.; Buonanno, A.; Burguet-Castell, J.; Byer, R. L.; Cadonati, L.; Camp, J. B.; Campsie, P.; Cannon, K.; Cao, J.; Capano, C. D.; Carbone, L.; Caride, S.; Castiglia, A. D.; Caudill, S.; Cavaglià, M.; Cepeda, C.; Chalermsongsak, T.; Chao, S.; Charlton, P.; Chen, X.; Chen, Y.; Cho, H.-S.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S. S. Y.; Chung, C. T. Y.; Ciani, G.; Clara, F.; Clark, D. E.; Clark, J. A.; Constancio Junior, M.; Cook, D.; Corbitt, T. R.; Cordier, M.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M. W.; Countryman, S.; Couvares, P.; Coward, D. M.; Cowart, M.; Coyne, D. C.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Cumming, A.; Cunningham, L.; Dahl, K.; Damjanic, M.; Danilishin, S. L.; Danzmann, K.; Daudert, B.; Daveloza, H.; Davies, G. S.; Daw, E. J.; Dayanga, T.; Deleeuw, E.; Denker, T.; Dent, T.; Dergachev, V.; Derosa, R.; Desalvo, R.; Dhurandhar, S.; di Palma, I.; Díaz, M.; Dietz, A.; Donovan, F.; Dooley, K. L.; Doravari, S.; Drasco, S.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Dumas, J.-C.; Dwyer, S.; Eberle, T.; Edwards, M.; Effler, A.; Ehrens, P.; Eikenberry, S. S.; Engel, R.; Essick, R.; Etzel, T.; Evans, K.; Evans, M.; Evans, T.; Factourovich, M.; Fairhurst, S.; Fang, Q.; Farr, B. F.; Farr, W.; Favata, M.; Fazi, D.; Fehrmann, H.; Feldbaum, D.; Finn, L. S.; Fisher, R. P.; Foley, S.; Forsi, E.; Fotopoulos, N.; Frede, M.; Frei, M. A.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Friedrich, D.; Fritschel, P.; Frolov, V. V.; Fujimoto, M.-K.; Fulda, P. J.; Fyffe, M.; Gair, J.; Garcia, J.; Gehrels, N.; Gelencser, G.; Gergely, L. Á.; Ghosh, S.; Giaime, J. A.; Giampanis, S.; Giardina, K. D.; Gil-Casanova, S.; Gill, C.; Gleason, J.; Goetz, E.; González, G.; Gordon, N.; Gorodetsky, M. L.; Gossan, S.; Goßler, S.; Graef, C.; Graff, P. B.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Griffo, C.; Grote, H.; Grover, K.; Grunewald, S.; Guido, C.; Gustafson, E. K.; Gustafson, R.; Hammer, D.; Hammond, G.; Hanks, J.; Hanna, C.; Hanson, J.; Haris, K.; Harms, J.; Harry, G. M.; Harry, I. W.; Harstad, E. D.; Hartman, M. T.; Haughian, K.; Hayama, K.; Heefner, J.; Heintze, M. C.; Hendry, M. A.; Heng, I. S.; Heptonstall, A. W.; Heurs, M.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Holt, K.; Holtrop, M.; Hong, T.; Hooper, S.; Hough, J.; Howell, E. J.; Huang, V.; Huerta, E. A.; Hughey, B.; Huttner, S. H.; Huynh, M.; Huynh-Dinh, T.; Ingram, D. R.; Inta, R.; Isogai, T.; Ivanov, A.; Iyer, B. R.; Izumi, K.; Jacobson, M.; James, E.; Jang, H.; Jang, Y. J.; Jesse, E.; Johnson, W. W.; Jones, D.; Jones, D. I.; Jones, R.; Ju, L.; Kalmus, P.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kasturi, R.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kawabe, K.; Kawamura, S.; Kawazoe, F.; Keitel, D.; Kelley, D. B.; Kells, W.; Keppel, D. G.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, B. K.; Kim, C.; Kim, K.; Kim, N.; Kim, Y.-M.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kline, J.; Kokeyama, K.; Kondrashov, V.; Koranda, S.; Korth, W. Z.; Kozak, D.; Kozameh, C.; Kremin, A.; Kringel, V.; Krishnan, B.; Kucharczyk, C.; Kuehn, G.; Kumar, P.; Kumar, R.; Kuper, B. J.; Kurdyumov, R.; Kwee, P.; Lam, P. K.; Landry, M.; Lantz, B.; Lasky, P. D.; Lawrie, C.; Lazzarini, A.; Le Roux, A.; Leaci, P.; Lee, C.-H.; Lee, H. K.; Lee, H. M.; Lee, J.; Leong, J. R.; Levine, B.; Lhuillier, V.; Lin, A. C.; Litvine, V.; Liu, Y.; Liu, Z.; Lockerbie, N. A.; Lodhia, D.; Loew, K.; Logue, J.; Lombardi, A. L.; Lormand, M.; Lough, J.; Lubinski, M.; Lück, H.; Lundgren, A. P.; MacArthur, J.; MacDonald, E.; Machenschalk, B.; Macinnis, M.; MacLeod, D. M.; Magaña-Sandoval, F.; Mageswaran, M.; Mailand, K.; Manca, G.; Mandel, I.; Mandic, V.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martin, I. W.; Martin, R. M.; Martinov, D.; Marx, J. N.; Mason, K.; Matichard, F.; Matone, L.; Matzner, R. A.; Mavalvala, N.; May, G.; Mazzolo, G.; McAuley, K.; McCarthy, R.; McClelland, D. E.; McGuire, S. C.; McIntyre, G.; McIver, J.; Meadors, G. D.; Mehmet, M.; Meier, T.; Melatos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyer, M. S.; Miao, H.; Miller, J.; Mingarelli, C. M. F.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moe, B.; Mokler, F.; Mohapatra, S. R. P.; Moraru, D.; Moreno, G.; Mori, T.; Morriss, S. R.; Mossavi, K.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nanda Kumar, D.; Nash, T.; Nayak, R.; Necula, V.; Newton, G.; Nguyen, T.; Nishida, E.; Nishizawa, A.; Nitz, A.; Nolting, D.; Normandin, M. E.; Nuttall, L. K.; O'Dell, J.; O'Reilly, B.; O'Shaughnessy, R.; Ochsner, E.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oppermann, P.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Ou, J.; Overmier, H.; Owen, B. J.; Padilla, C.; Pai, A.; Pan, Y.; Pankow, C.; Papa, M. A.; Paris, H.; Parkinson, W.; Pedraza, M.; Penn, S.; Peralta, C.; Perreca, A.; Phelps, M.; Pickenpack, M.; Pierro, V.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Pöld, J.; Postiglione, F.; Poux, C.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Privitera, S.; Prokhorov, L. G.; Puncken, O.; Quetschke, V.; Quintero, E.; Quitzow-James, R.; Raab, F. J.; Radkins, H.; Raffai, P.; Raja, S.; Rakhmanov, M.; Ramet, C.; Raymond, V.; Reed, C. M.; Reed, T.; Reid, S.; Reitze, D. H.; Riesen, R.; Riles, K.; Roberts, M.; Robertson, N. A.; Robinson, E. L.; Roddy, S.; Rodriguez, C.; Rodriguez, L.; Rodruck, M.; Rollins, J. G.; Romie, J. H.; Röver, C.; Rowan, S.; Rüdiger, A.; Ryan, K.; Salemi, F.; Sammut, L.; Sandberg, V.; Sanders, J.; Sankar, S.; Sannibale, V.; Santamaría, L.; Santiago-Prieto, I.; Santostasi, G.; Sathyaprakash, B. S.; Saulson, P. R.; Savage, R. L.; Schilling, R.; Schnabel, R.; Schofield, R. M. S.; Schuette, D.; Schulz, B.; Schutz, B. F.; Schwinberg, P.; Scott, J.; Scott, S. M.; Seifert, F.; Sellers, D.; Sengupta, A. S.; Sergeev, A.; Shaddock, D. A.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sidery, T. L.; Siemens, X.; Sigg, D.; Simakov, D.; Singer, A.; Singer, L.; Sintes, A. M.; Skelton, G. R.; Slagmolen, B. J. J.; Slutsky, J.; Smith, J. R.; Smith, M. R.; Smith, R. J. E.; Smith-Lefebvre, N. D.; Son, E. J.; Sorazu, B.; Souradeep, T.; Stefszky, M.; Steinert, E.; Steinlechner, J.; Steinlechner, S.; Steplewski, S.; Stevens, D.; Stochino, A.; Stone, R.; Strain, K. A.; Strigin, S. E.; Stroeer, A. S.; Stuver, A. L.; Summerscales, T. Z.; Susmithan, S.; Sutton, P. J.; Szeifert, G.; Talukder, D.; Tanner, D. B.; Tarabrin, S. P.; Taylor, R.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Torres, C. V.; Torrie, C. I.; Traylor, G.; Tse, M.; Ugolini, D.; Unnikrishnan, C. S.; Vahlbruch, H.; Vallisneri, M.; van der Sluys, M. V.; van Veggel, A. A.; Vass, S.; Vaulin, R.; Vecchio, A.; Veitch, P. J.; Veitch, J.; Venkateswara, K.; Verma, S.; Vincent-Finley, R.; Vitale, S.; Vo, T.; Vorvick, C.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A.; Wade, L.; Wade, M.; Waldman, S. J.; Wallace, L.; Wan, Y.; Wang, M.; Wang, J.; Wang, X.; Wanner, A.; Ward, R. L.; Was, M.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Wessels, P.; West, M.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; Wiseman, A. G.; White, D. J.; Whiting, B. F.; Wiesner, K.; Wilkinson, C.; Willems, P. A.; Williams, L.; Williams, R.; Williams, T.; Willis, J. L.; Willke, B.; Wimmer, M.; Winkelmann, L.; Winkler, W.; Wipf, C.; Wittel, H.; Woan, G.; Wooley, R.; Worden, J.; Yablon, J.; Yakushin, I.; Yamamoto, H.; Yancey, C. C.; Yang, H.; Yeaton-Massey, D.; Yoshida, S.; Yum, H.; Zanolin, M.; Zhang, F.; Zhang, L.; Zhao, C.; Zhu, H.; Zhu, X. J.; Zotov, N.; Zucker, M. E.; Zweizig, J.

2013-08-01

Nearly a century after Einstein first predicted the existence of gravitational waves, a global network of Earth-based gravitational wave observatories is seeking to directly detect this faint radiation using precision laser interferometry. Photon shot noise, due to the quantum nature of light, imposes a fundamental limit on the attometre-level sensitivity of the kilometre-scale Michelson interferometers deployed for this task. Here, we inject squeezed states to improve the performance of one of the detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) beyond the quantum noise limit, most notably in the frequency region down to 150 Hz, critically important for several astrophysical sources, with no deterioration of performance observed at any frequency. With the injection of squeezed states, this LIGO detector demonstrated the best broadband sensitivity to gravitational waves ever achieved, with important implications for observing the gravitational-wave Universe with unprecedented sensitivity.

Monitoring the englacial fracture state using virtual-reflector seismology

NASA Astrophysics Data System (ADS)

Lindner, F.; Weemstra, C.; Walter, F.; Hadziioannou, C.

2017-12-01

Fracturing and changes in the englacial macroscopic water content change the elastic bulk properties of ice bodies. Small seismic velocity variations, resulting from such changes, can be measured using a technique called coda-wave interferometry. Here, coda refers to the later-arriving, multiply scattered waves. Often, this technique is applied to so-called virtual-source responses, which can be obtained using seismic interferometry (a simple crosscorrelation process). Compared to other media (e.g., the Earth's crust), however, ice bodies exhibit relatively little scattering. This complicates the application of coda-wave interferometry to the retrieved virtual-source responses. In this work, we therefore investigate the applicability of coda-wave interferometry to virtual-source responses obtained using two alternative seismic interferometric techniques, namely, seismic interferometry by multidimensional deconvolution (SI by MDD), and virtual-reflector seismology (VRS). To that end, we use synthetic data, as well as active-source glacier data acquired on Glacier de la Plaine Morte, Switzerland. Both SI by MDD and VRS allow the retrieval of more accurate virtual-source responses. In particular, the dependence of the retrieved virtual-source responses on the illumination pattern is reduced. We find that this results in more accurate glacial phase-velocity estimates. In addition, VRS introduces virtual reflections from a receiver contour (partly) enclosing the medium of interest. By acting as a sort of virtual reverberation, the coda resulting from the application of VRS significantly increases seismic monitoring capabilities, in particular in cases where natural scattering coda is not available.

Possible Space-Based Gravitational-Wave Observatory Mission Concept

NASA Technical Reports Server (NTRS)

Livas, Jeffrey C.

2015-01-01

The existence of gravitational waves was established by the discovery of the Binary Pulsar PSR 1913+16 by Hulse and Taylor in 1974, for which they were awarded the 1983 Nobel Prize. However, it is the exploitation of these gravitational waves for the extraction of the astrophysical parameters of the sources that will open the first new astronomical window since the development of gamma ray telescopes in the 1970's and enable a new era of discovery and understanding of the Universe. Direct detection is expected in at least two frequency bands from the ground before the end of the decade with Advanced LIGO and Pulsar Timing Arrays. However, many of the most exciting sources will be continuously observable in the band from 0.1-100 mHz, accessible only from space due to seismic noise and gravity gradients in that band that disturb ground-based observatories. This poster will discuss a possible mission concept, Space-based Gravitational-wave Observatory (SGO-Mid) developed from the original Laser Interferometer Space Antenna (LISA) reference mission but updated to reduce risk and cost.

The Virtual Earth-Solar Observatory of the SCiESMEX

NASA Astrophysics Data System (ADS)

De la Luz, V.; Gonzalez-Esparza, A.; Cifuentes-Nava, G.

2015-12-01

The Mexican Space Weather Service (SCiESMEX, http://www.sciesmex.unam.mx) started operations in October 2014. The project includes the Virtual Earth-Solar Observatory (VESO, http://www.veso.unam.mx). The VESO is a improved project wich objetive is integrate the space weather instrumentation network from the National Autonomous University of Mexico (UNAM). The network includes the Mexican Array Radiotelescope (MEXART), the Callisto receptor (MEXART), a Neutron Telescope, a Cosmic Ray Telescope. the Schumann Antenna, the National Magnetic Service, and the mexican GPS network (TlalocNet). The VESO facility is located at the Geophysics Institute campus Michoacan (UNAM). We offer the service of data store, real-time data, and quasi real-time data. The hardware of VESO includes a High Performance Computer (HPC) dedicated specially to big data storage.

iSERVO: Implementing the International Solid Earth Research Virtual Observatory by Integrating Computational Grid and Geographical Information Web Services

NASA Astrophysics Data System (ADS)

Aktas, Mehmet; Aydin, Galip; Donnellan, Andrea; Fox, Geoffrey; Granat, Robert; Grant, Lisa; Lyzenga, Greg; McLeod, Dennis; Pallickara, Shrideep; Parker, Jay; Pierce, Marlon; Rundle, John; Sayar, Ahmet; Tullis, Terry

2006-12-01

We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical Information System (GIS)-based data grid services for accessing remote data repositories and job management services for controlling multiple execution steps. iSERVO is an example of a larger trend to build globally scalable scientific computing infrastructures using the Service Oriented Architecture approach. Adoption of this approach raises a number of research challenges in millisecond-latency message systems suitable for internet-enabled scientific applications. We review our research in these areas.

A population of compact elliptical galaxies detected with the Virtual Observatory.

PubMed

Chilingarian, Igor; Cayatte, Véronique; Revaz, Yves; Dodonov, Serguei; Durand, Daniel; Durret, Florence; Micol, Alberto; Slezak, Eric

2009-12-04

Compact elliptical galaxies are characterized by small sizes and high stellar densities. They are thought to form through tidal stripping of massive progenitors. However, only a handful of them were known, preventing us from understanding the role played by this mechanism in galaxy evolution. We present a population of 21 compact elliptical galaxies gathered with the Virtual Observatory. Follow-up spectroscopy and data mining, using high-resolution images and large databases, show that all the galaxies exhibit old metal-rich stellar populations different from those of dwarf elliptical galaxies of similar masses but similar to those of more massive early-type galaxies, supporting the tidal stripping scenario. Their internal properties are reproduced by numerical simulations, which result in compact, dynamically hot remnants resembling the galaxies in our sample.

The International Outer Planets Watch atmospheres node database of giant-planet images

NASA Astrophysics Data System (ADS)

Hueso, R.; Legarreta, J.; Sánchez-Lavega, A.; Rojas, J. F.; Gómez-Forrellad, J. M.

2011-10-01

The Atmospheres Node of the International Outer Planets Watch (IOPW) is aimed to encourage the observations and study of the atmospheres of the Giant Planets. One of its main activities is to provide an interaction between the professional and amateur astronomical communities maintaining an online and fully searchable database of images of the giant planets obtained from amateur astronomers and available to both professional and amateurs [1]. The IOPW database contains about 13,000 image observations of Jupiter and Saturn obtained in the visible range with a few contributions of Uranus and Neptune. We describe the organization and structure of the database as posted in the Internet and in particular the PVOL software (Planetary Virtual Observatory & Laboratory) designed to manage the site and based in concepts from Virtual Observatory projects.

Astroinformatics as a New Research Field. UkrVO Astroinformation Resources: Tasks and Prospective

NASA Astrophysics Data System (ADS)

Vavilova, I. B.

The data-oriented astronomy has allowed classifying the Astroinformatics as a new academic research field, which covers various multi-disciplinary applications of the e-Astronomy. Among them are the data modeling, data mining, metadata standards development, data access, digital astronomical databases, image archives and visualization, machine learning, statistics and other computational methods and software for work with astronomical survey and catalogues with their teta- topeta-scale astroinformation resource. In this review we describe briefly the astroinformatics applications and software/services performed for different astronomical tasks in frame of the VIrtual Roentgen and Gamma Observatory (VIRGO) and Ukrainian VirtualObservatory (UkrVO). Among them there are projects based on the archival space-born data of X-ray and gamma space observatories and on the Joint Digitized Archive (JDA) database of astroplate network collections. The UkrVO JDA DR1 deals with the star catalogues (FON, Polar zone, open clusters, GRB star fields) as well as the UkrVO JDA DR2 deals with the Solar System bodies (giant and small planets, satellites, astronomical heritage images).

Computational assessment of model-based wave separation using a database of virtual subjects.

PubMed

Hametner, Bernhard; Schneider, Magdalena; Parragh, Stephanie; Wassertheurer, Siegfried

2017-11-07

The quantification of arterial wave reflection is an important area of interest in arterial pulse wave analysis. It can be achieved by wave separation analysis (WSA) if both the aortic pressure waveform and the aortic flow waveform are known. For better applicability, several mathematical models have been established to estimate aortic flow solely based on pressure waveforms. The aim of this study is to investigate and verify the model-based wave separation of the ARCSolver method on virtual pulse wave measurements. The study is based on an open access virtual database generated via simulations. Seven cardiac and arterial parameters were varied within physiological healthy ranges, leading to a total of 3325 virtual healthy subjects. For assessing the model-based ARCSolver method computationally, this method was used to perform WSA based on the aortic root pressure waveforms of the virtual patients. Asa reference, the values of WSA using both the pressure and flow waveforms provided by the virtual database were taken. The investigated parameters showed a good overall agreement between the model-based method and the reference. Mean differences and standard deviations were -0.05±0.02AU for characteristic impedance, -3.93±1.79mmHg for forward pressure amplitude, 1.37±1.56mmHg for backward pressure amplitude and 12.42±4.88% for reflection magnitude. The results indicate that the mathematical blood flow model of the ARCSolver method is a feasible surrogate for a measured flow waveform and provides a reasonable way to assess arterial wave reflection non-invasively in healthy subjects. Copyright © 2017 Elsevier Ltd. All rights reserved.

VITMO: A Case Study in Virtual Observatories as Data Portals and Development of Web Services as Search Tools

NASA Astrophysics Data System (ADS)

Smith, D.; Barnes, R. J.; Morrison, D.; Talaat, E. R.; Potter, M.; Patrone, D.; Weiss, M.; Sarris, T.

2013-12-01

Virtual Observatories are more than data portals that span multiple missions and data sets. They need to provide a system that is useable by a broad swath of people with different backgrounds. The great promise of Virtual Observatories is the ability to perform complex search operations on a large variety of different data sets. This allows the researcher to isolate and select the relevant measurements for their topic of study. The Virtual ITM Observatory (VITMO) is unique in having many diverse datasets that cover a large temporal and spatial range that present a unique search problem. VITMO provides many methods by which the user can search for and select data of interest including restricting selections based on geophysical conditions (solar wind speed, Kp, etc) as well as finding those datasets that overlap in time and/or space. We are developing a series of light-weight web services that will provide a new data search capability for VITMO and other VxOs. The services will consist of a database of spacecraft ephemerides and instrument fields of view; an overlap calculator to find times when the fields of view of different instruments intersect; and a magnetic field line tracing service that will map in situ and ground based measurements to the equatorial plane in magnetic coordinates for a number of field models and geophysical conditions. Each service on their own provides a useful new capability for virtual observatories; operating together they will provide a powerful new search tool. The ephemerides service is being built using the Navigation and Ancillary Information Facility (NAIF) SPICE toolkit (http://naif.jpl.nasa.gov/naif/index.html) allowing them to be extended to support any Earth orbiting satellite with the addition of the appropriate SPICE kernels or two-line element sets (TLE). An instrument kernel (IK) file will be used to describe the observational geometry of the instrument (e.g., Field-of-view size, shape, and orientation). The overlap calculator uses techniques borrowed from computer graphics to identify overlapping measurements in space and time. The calculator will allow a user defined uncertainty to be selected to allow 'near misses' to be found. The magnetic field tracing service will feature a database of pre-calculated field line tracings of ground stations but will also allow dynamic tracing of arbitrary coordinates. These services will allow the non-specialist user of VITMO to select data that they were previously unable to locate, opening up analysis opportunities beyond the instrument teams and making it much easier for future students who come into the field.

Parsimonious surface wave interferometry

NASA Astrophysics Data System (ADS)

Li, Jing; Hanafy, Sherif; Schuster, Gerard T.

2018-03-01

To decrease the recording time of a 2-D seismic survey from a few days to one hour or less, we present a parsimonious surface wave interferometry method. Interferometry allows for the creation of a large number of virtual shot gathers from just two reciprocal shot gathers by crosscoherence of trace pairs. Then, the virtual surface waves can be inverted for the S-wave velocity model by wave-equation dispersion inversion (WD). Synthetic and field data tests suggest that parsimonious WD (PWD) gives S-velocity tomograms that are comparable to those obtained from a conventional survey with a shot at each receiver. The limitation of PWD is that the virtual data lose some information so that the resolution of the S-velocity tomogram can be modestly lower than that of the S-velocity tomogram inverted from a conventional survey.

The Galics Project: Virtual Galaxy: from Cosmological N-body Simulations

NASA Astrophysics Data System (ADS)

Guiderdoni, B.

The GalICS project develops extensive semi-analytic post-processing of large cosmological simulations to describe hierarchical galaxy formation. The multiwavelength statistical properties of high-redshift and local galaxies are predicted within the large-scale structures. The fake catalogs and mock images that are generated from the outputs are used for the analysis and preparation of deep surveys. The whole set of results is now available in an on-line database that can be easily queried. The GalICS project represents a first step towards a 'Virtual Observatory of virtual galaxies'.

Accessing Multi-Dimensional Images and Data Cubes in the Virtual Observatory

NASA Astrophysics Data System (ADS)

Tody, Douglas; Plante, R. L.; Berriman, G. B.; Cresitello-Dittmar, M.; Good, J.; Graham, M.; Greene, G.; Hanisch, R. J.; Jenness, T.; Lazio, J.; Norris, P.; Pevunova, O.; Rots, A. H.

2014-01-01

Telescopes across the spectrum are routinely producing multi-dimensional images and datasets, such as Doppler velocity cubes, polarization datasets, and time-resolved “movies.” Examples of current telescopes producing such multi-dimensional images include the JVLA, ALMA, and the IFU instruments on large optical and near-infrared wavelength telescopes. In the near future, both the LSST and JWST will also produce such multi-dimensional images routinely. High-energy instruments such as Chandra produce event datasets that are also a form of multi-dimensional data, in effect being a very sparse multi-dimensional image. Ensuring that the data sets produced by these telescopes can be both discovered and accessed by the community is essential and is part of the mission of the Virtual Observatory (VO). The Virtual Astronomical Observatory (VAO, http://www.usvao.org/), in conjunction with its international partners in the International Virtual Observatory Alliance (IVOA), has developed a protocol and an initial demonstration service designed for the publication, discovery, and access of arbitrarily large multi-dimensional images. The protocol describing multi-dimensional images is the Simple Image Access Protocol, version 2, which provides the minimal set of metadata required to characterize a multi-dimensional image for its discovery and access. A companion Image Data Model formally defines the semantics and structure of multi-dimensional images independently of how they are serialized, while providing capabilities such as support for sparse data that are essential to deal effectively with large cubes. A prototype data access service has been deployed and tested, using a suite of multi-dimensional images from a variety of telescopes. The prototype has demonstrated the capability to discover and remotely access multi-dimensional data via standard VO protocols. The prototype informs the specification of a protocol that will be submitted to the IVOA for approval, with an operational data cube service to be delivered in mid-2014. An associated user-installable VO data service framework will provide the capabilities required to publish VO-compatible multi-dimensional images or data cubes.

Wave field synthesis of a virtual source located in proximity to a loudspeaker array.

PubMed

Lee, Jung-Min; Choi, Jung-Woo; Kim, Yang-Hann

2013-09-01

For the derivation of 2.5-dimensional operator in wave field synthesis, a virtual source is assumed to be positioned far from a loudspeaker array. However, such far-field approximation inevitably results in a reproduction error when the virtual source is placed adjacent to an array. In this paper, a method is proposed to generate a virtual source close to and behind a continuous line array of loudspeakers. A driving function is derived by reducing a surface integral (Rayleigh integral) to a line integral based on the near-field assumption. The solution is then combined with the far-field formula of wave field synthesis by introducing a weighting function that can adjust the near- and far-field contribution of each driving function. This enables production of a virtual source anywhere in relation to the array. Simulations show the proposed method can reduce the reproduction error to below -18 dB, regardless of the virtual source position.

Beyond seismic interferometry: imaging the earth's interior with virtual sources and receivers inside the earth

NASA Astrophysics Data System (ADS)

Wapenaar, C. P. A.; Van der Neut, J.; Thorbecke, J.; Broggini, F.; Slob, E. C.; Snieder, R.

2015-12-01

Imagine one could place seismic sources and receivers at any desired position inside the earth. Since the receivers would record the full wave field (direct waves, up- and downward reflections, multiples, etc.), this would give a wealth of information about the local structures, material properties and processes in the earth's interior. Although in reality one cannot place sources and receivers anywhere inside the earth, it appears to be possible to create virtual sources and receivers at any desired position, which accurately mimics the desired situation. The underlying method involves some major steps beyond standard seismic interferometry. With seismic interferometry, virtual sources can be created at the positions of physical receivers, assuming these receivers are illuminated isotropically. Our proposed method does not need physical receivers at the positions of the virtual sources; moreover, it does not require isotropic illumination. To create virtual sources and receivers anywhere inside the earth, it suffices to record the reflection response with physical sources and receivers at the earth's surface. We do not need detailed information about the medium parameters; it suffices to have an estimate of the direct waves between the virtual-source positions and the acquisition surface. With these prerequisites, our method can create virtual sources and receivers, anywhere inside the earth, which record the full wave field. The up- and downward reflections, multiples, etc. in the virtual responses are extracted directly from the reflection response at the surface. The retrieved virtual responses form an ideal starting point for accurate seismic imaging, characterization and monitoring.

Mode Conversion of a Solar Extreme-ultraviolet Wave over a Coronal Cavity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zong, Weiguo; Dai, Yu, E-mail: ydai@nju.edu.cn

2017-01-10

We report on observations of an extreme-ultraviolet (EUV) wave event in the Sun on 2011 January 13 by Solar Terrestrial Relations Observatory and Solar Dynamics Observatory in quadrature. Both the trailing edge and the leading edge of the EUV wave front in the north direction are reliably traced, revealing generally compatible propagation velocities in both perspectives and a velocity ratio of about 1/3. When the wave front encounters a coronal cavity near the northern polar coronal hole, the trailing edge of the front stops while its leading edge just shows a small gap and extends over the cavity, meanwhile gettingmore » significantly decelerated but intensified. We propose that the trailing edge and the leading edge of the northward propagating wave front correspond to a non-wave coronal mass ejection component and a fast-mode magnetohydrodynamic wave component, respectively. The interaction of the fast-mode wave and the coronal cavity may involve a mode conversion process, through which part of the fast-mode wave is converted to a slow-mode wave that is trapped along the magnetic field lines. This scenario can reasonably account for the unusual behavior of the wave front over the coronal cavity.« less

Shear wave velocity measurements for differential diagnosis of solid breast masses: a comparison between virtual touch quantification and virtual touch IQ.

PubMed

Tozaki, Mitsuhiro; Saito, Masahiro; Benson, John; Fan, Liexiang; Isobe, Sachiko

2013-12-01

This study compared the diagnostic performance of two shear wave speed measurement techniques in 81 patients with 83 solid breast lesions. Virtual Touch Quantification, which provides single-point shear wave speed measurement capability (SP-SWS), was compared with Virtual Touch IQ, a new 2-D shear wave imaging technique with multi-point shear wave speed measurement capability (2D-SWS). With SP-SWS, shear wave velocity was measured within the lesion ("internal" value) and the marginal areas ("marginal" value). With 2D-SWS, the highest velocity was measured. The marginal values obtained with the SP-SWS and 2D-SWS methods were significantly higher for malignant lesions and benign lesions, respectively (p < 0.0001). Sensitivity, specificity and accuracy were 86% (36/42), 90% (37/41) and 88% (73/83), respectively, for SP-SWS, and 88% (37/42), 93% (38/41) and 90% (75/83), respectively, for 2D-SWS. It is concluded that 2D-SWS is a useful diagnostic tool for differentiating malignant from benign solid breast masses. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Astronomy from the chair - the application of the Internet in promoting of Astronomy

NASA Astrophysics Data System (ADS)

Tomic, Zoran

2014-05-01

Internet and modern communication technologies are an indispensable part of modern life. The use of the Internet makes it possible to enhance the education and expand opportunities for acquiring new knowledge. One example is Astronomy, where today thanks to the Internet, we can control telescopes that are distant from us and listen to lectures from Universities in other countries. "Astronomy from the chair" is the name for a concept where amateur astronomers can deal with astronomy from their homes using the Internet. The concept can be divided into four sections depending on the content being offered: Robotic Observatory, Virtual Observatory, Online astronomy broadcasting and Online courses. Robotic observatory is defined as an astronomical instrument and detection system that enables efficient observation without the need of a person's physical intervention. Virtual Observatory is defined as a collection of databases and software tools that use the Internet as a platform for scientific research. Online astronomy broadcasting is part of concept "Astronomy from the chair" which gives users the opportunity to get directly involved in astronomical observation organized by an amateur astronomer from somewhere in the world. Online courses are groups of sites and organizations that provide the opportunity to amateur astronomers to attend lectures, save and watch video materials from lectures, do homework, communicate with other seminar participants and in that way become familiar with the various areas of Astronomy. This paper discusses a new concept that describes how the Internet can be applied in modern education. In this paper will be described projects that allows a large number of astronomy lovers to do their own research without the need to own a large and expensive set of astronomical equipment (Virtual Telescope from Italy, Observatory "Night Hawk" from Serbia and project "Astronomy from an armchair" at Faculty of Sciences and Mathematics in Nis), to help professional astronomers in research of galaxies, extrasolar systems, Moon etc. without the need of owning the official certificate in Astronomy (Planet Hunters, Moon Zoo) and the possibility to attend online courses in Astronomy (Introduction to Astronomy from the site Coursera). In the end, will be discussion about economic analysis of using robotic observatory in contemporary education and the implementation of research projects, rather than Institutions to invest huge amounts of funds in the purchase and maintenance of the same astronomical equipment.

Finite Element Methods for Modelling Mechanical Loss in LIGO coating optics.

NASA Astrophysics Data System (ADS)

Newport, Jonathan; Harry, Gregg; LIGO Collaboration

2015-04-01

Gravitational waves from sources such as binary star systems, supernovae explosions and stochastic background radiation have yet to be directly detected by experimental observations. Alongside international collaborators, the Laser Interferometer Gravitational-Wave Observatory (LIGO) is designed to realize detection of gravitational waves using interferometric techniques. The second generation of gravitational wave observatories, known as Advanced LIGO, are currently undergoing installation and commissioning at sites in Hanford, Washington and Livingston, Louisiana. The ultimate sensitivity of Advanced LIGO within select spectral bands is limited by thermal noise in the coatings of the interferometer optics. The LIGO lab at American University is measuring the mechanical loss of coated substrates to predict thermal noise within these spectral bands. These predictions use increasingly sophisticated finite element models to ensure the ultimate design sensitivity of Advanced LIGO and to study coating and substrate materials for future gravitational wave detectors.

Source signature estimation from multimode surface waves via mode-separated virtual real source method

NASA Astrophysics Data System (ADS)

Gao, Lingli; Pan, Yudi

2018-05-01

The correct estimation of the seismic source signature is crucial to exploration geophysics. Based on seismic interferometry, the virtual real source (VRS) method provides a model-independent way for source signature estimation. However, when encountering multimode surface waves, which are commonly seen in the shallow seismic survey, strong spurious events appear in seismic interferometric results. These spurious events introduce errors in the virtual-source recordings and reduce the accuracy of the source signature estimated by the VRS method. In order to estimate a correct source signature from multimode surface waves, we propose a mode-separated VRS method. In this method, multimode surface waves are mode separated before seismic interferometry. Virtual-source recordings are then obtained by applying seismic interferometry to each mode individually. Therefore, artefacts caused by cross-mode correlation are excluded in the virtual-source recordings and the estimated source signatures. A synthetic example showed that a correct source signature can be estimated with the proposed method, while strong spurious oscillation occurs in the estimated source signature if we do not apply mode separation first. We also applied the proposed method to a field example, which verified its validity and effectiveness in estimating seismic source signature from shallow seismic shot gathers containing multimode surface waves.

Global TIE Observatories: Real Time Observational Astronomy Through a Robotic Telescope Network

NASA Astrophysics Data System (ADS)

Clark, G.; Mayo, L. A.

2001-12-01

Astronomy in grades K-12 is traditionally taught (if at all) using textbooks and a few simple hands-on activities. Teachers are generally not trained in observational astronomy techniques and are unfamiliar with the most basic astronomical concepts. In addition, most students, by High School graduation, will never have even looked through the eyepiece of a telescope. The problem becomes even more challenging in inner cities, remote rural areas and low socioeconomic communities where educational emphasis on topics in astronomy as well as access to observing facilities is limited or non existent. Access to most optical telescope facilities is limited to monthly observing nights that cater to a small percentage of the general public living near the observatory. Even here, the observing experience is a one-time event detached from the process of scientific enquiry and sustained educational application. Additionally, a number of large, "research grade" observatory facilities are largely unused, partially due to the slow creep of light pollution around the facilities as well as the development of newer, more capable telescopes. Though cutting edge science is often no longer possible at these sights, real research opportunities in astronomy remain numerous for these facilities as educational tools. The possibility now exists to establish a network of research grade telescopes, no longer useful to the professional astronomical community, that can be made accessible through classrooms, after school, and community based programs all across the country through existing IT technologies and applications. These telescopes could provide unparalleled research and educational opportunities for a broad spectrum of students and turns underutilized observatory facilities into valuable, state-of-the-art teaching centers. The NASA sponsored Telescopes In Education project has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. Global TIE integrates these telescopes seamlessly into one virtual observatory and provides the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J" for publication of results, and access to related educational materials provided by the TIE community. This presentation describes the Global TIE Observatory data and organizational systems and details the technology, partnerships, operational capabilities, science applications, and learning opportunities that this powerful virtual observatory network will provide.

VirGO: A Visual Browser for the ESO Science Archive Facility

NASA Astrophysics Data System (ADS)

Hatziminaoglou, Evanthia; Chéreau, Fabien

2009-03-01

VirGO is the next generation Visual Browser for the ESO Science Archive Facility (SAF) developed in the Virtual Observatory Project Office. VirGO enables astronomers to discover and select data easily from millions of observations in a visual and intuitive way. It allows real-time access and the graphical display of a large number of observations by showing instrumental footprints and image previews, as well as their selection and filtering for subsequent download from the ESO SAF web interface. It also permits the loading of external FITS files or VOTables, as well as the superposition of Digitized Sky Survey images to be used as background. All data interfaces are based on Virtual Observatory (VO) standards that allow access to images and spectra from external data centres, and interaction with the ESO SAF web interface or any other VO applications.

Heliophysics Data and Modeling Research Using VSPO

NASA Technical Reports Server (NTRS)

Roberts, D. Aaron; Hesse, Michael; Cornwell, Carl

2007-01-01

The primary advantage of Virtual Observatories in scientific research is efficiency: rapid searches for and access to data in convenient forms makes it possible to explore scientific questions without spending days or weeks on ancilary tasks. The Virtual Space Physics Observatory provides a general portal to Heliophysics data for this task. Here we will illustrate the advantages of the VO approach by examining specific geomagnetically active times and tracing the activity through the Sun-Earth system. In addition to previous and additional data sources, we will demonstrate an extension of the capabilities to allow searching for model run results from the range of CCMC models. This approach allows the user to quickly compare models and observations at a qualitative level; considerably more work will be needed to develop more seamless connections to data streams and the equivalent numerical output from simulations.

Asteroseismology and the Virtual Observatory

NASA Astrophysics Data System (ADS)

Suárez, J. C.

2010-12-01

Virtual Observatory is an international project aiming at solving the problem of interoperability among astronomical archives and the scalability in the classical methods of retrieving and analyzing astronomical data in order to deal with huge amounts of datasets. This is being tackled thanks to the standardization of astronomical archives favoring their access in a efficient manner. This project, which is nowadays a reality, is more and more adopted by many fields of Science. In the present paper I will describe the origin of a new era in Stellar Physics whose main role is played by the relationship between asteroseismology and V.O. I will summarize the main concerns of both fields and the current development of VO tools for the development of what we could name as asteroseismology online, in which not only observed datasets are concerned but also the management of model databases.

Virtual Solar Observatory Distributed Query Construction

NASA Technical Reports Server (NTRS)

Gurman, J. B.; Dimitoglou, G.; Bogart, R.; Davey, A.; Hill, F.; Martens, P.

2003-01-01

Through a prototype implementation (Tian et al., this meeting) the VSO has already demonstrated the capability of unifying geographically distributed data sources following the Web Services paradigm and utilizing mechanisms such as the Simple Object Access Protocol (SOAP). So far, four participating sites (Stanford, Montana State University, National Solar Observatory and the Solar Data Analysis Center) permit Web-accessible, time-based searches that allow browse access to a number of diverse data sets. Our latest work includes the extension of the simple, time-based queries to include numerous other searchable observation parameters. For VSO users, this extended functionality enables more refined searches. For the VSO, it is a proof of concept that more complex, distributed queries can be effectively constructed and that results from heterogeneous, remote sources can be synthesized and presented to users as a single, virtual data product.

Virtual Observatory Science Applications

NASA Technical Reports Server (NTRS)

McGlynn, Tom

2005-01-01

Many Virtual-Observatory-based applications are now available to astronomers for use in their research. These span data discovery, access, visualization and analysis. Tools can quickly gather and organize information from sites around the world to help in planning a response to a gamma-ray burst, help users pick filters to isolate a desired feature, make an average template for z=2 AGN, select sources based upon information in many catalogs, or correlate massive distributed databases. Using VO protocols, the reach of existing software tools and packages can be greatly extended, allowing users to find and access remote information almost as conveniently as local data. The talk highlights just a few of the tools available to scientists, describes how both large and small scale projects can use existing tools, and previews some of the new capabilities that will be available in the next few years.

Connecting the time domain community with the Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Graham, Matthew J.; Djorgovski, S. G.; Donalek, Ciro; Drake, Andrew J.; Mahabal, Ashish A.; Plante, Raymond L.; Kantor, Jeffrey; Good, John C.

2012-09-01

The time domain has been identied as one of the most important areas of astronomical research for the next decade. The Virtual Observatory is in the vanguard with dedicated tools and services that enable and facilitate the discovery, dissemination and analysis of time domain data. These range in scope from rapid notications of time-critical astronomical transients to annotating long-term variables with the latest modelling results. In this paper, we will review the prior art in these areas and focus on the capabilities that the VAO is bringing to bear in support of time domain science. In particular, we will focus on the issues involved with the heterogeneous collections of (ancilllary) data associated with astronomical transients, and the time series characterization and classication tools required by the next generation of sky surveys, such as LSST and SKA.

Lessons Learned to Date in Developing the Virtual Space Physics Observatory

NASA Astrophysics Data System (ADS)

Cornwell, C.; Roberts, D. A.; King, J.; Smith, A.

2005-12-01

We now have an operational Virtual Space Physics Observatory that provides users the ability to search for and retrieve data from hundreds of space and solar physics data products based on specific terms or a Google-like interface. Lessons learned in building VSPO include: (a) A very close and highly interactive collaboration between scientists and information technologists in the definition and development of services is essential. (b) Constructing a Data Model acceptable to a broad community is very important but very difficult. Variations in usage are inevitable and must be dealt with through translations; this is especially true for the description of variables within data products. (c) Higher-order queries (searches based on events, positions, comparisons of measurements, etc.) are possible, and have been implemented in various systems; currently we see these as being separate from the basic data finding and retrieval services. (d) Building a Virtual Observatory is often more a matter of the tedious details of product descriptions than an exercise in implementing fancy middleware. Paying a knowledgeable third party to build registries can be more efficient than working directly with providers, and automated tools can help but do not solve all the problems. (e) The success of the VO effort in space and solar physics, as elsewhere, will depend on whether the scientific communities involved use and critique the services so that they will come to meet a real need for the integration of resources to solve new scientific problems of perceived importance.

Taming the data wilderness with the VHO: Integrating heliospheric data sets

NASA Astrophysics Data System (ADS)

Schroeder, P.; Szabo, A.; Narock, T.

Currently space physicists are faced with a bewildering array of heliospheric missions experiments and data sets available at archives distributed around the world Daunting even for those most familiar with the field physicists in other concentrations solar physics magnetospheric physics etc find locating the heliospheric data that they need extremely challenging if not impossible The Virtual Heliospheric Observatory VHO will help to solve this problem by creating an Application Programming Interface API and web portal that integrates these data sets to find the highest quality data for a given task The VHO will locate the best available data often found only at PI institutions rather than at national archives like the NSSDC The VHO will therefore facilitate a dynamic data environment where improved data products are made available immediately In order to accomplish this the VHO will enforce a metadata standard on participating data providers with sufficient depth to allow for meaningful scientific evaluation of similar data products The VHO will provide an automated way for secondary sites to keep mirrors of data archives up to date and encouraging the generation of secondary or added-value data products The VHO will interact seamlessly with the Virtual Solar Observatory VSO and other Virtual Observatories VxO s to allow for inter-disciplinary data searching Software tools for these data sets will also be available through the VHO Finally the VHO will provide linkages to the modeling community and will develop metadata standards for the

A pilot Virtual Observatory (pVO) for integrated catchment science - Demonstration of national scale modelling of hydrology and biogeochemistry (Invited)

NASA Astrophysics Data System (ADS)

Freer, J. E.; Bloomfield, J. P.; Johnes, P. J.; MacLeod, C.; Reaney, S.

2010-12-01

There are many challenges in developing effective and integrated catchment management solutions for hydrology and water quality issues. Such solutions should ideally build on current scientific evidence to inform policy makers and regulators and additionally allow stakeholders to take ownership of local and/or national issues, in effect bringing together ‘communities of practice’. A strategy being piloted in the UK as the Pilot Virtual Observatory (pVO), funded by NERC, is to demonstrate the use of cyber-infrastructure and cloud computing resources to investigate better methods of linking data and models and to demonstrate scenario analysis for research, policy and operational needs. The research will provide new ways the scientific and stakeholder communities come together to exploit current environmental information, knowledge and experience in an open framework. This poster presents the project scope and methodologies for the pVO work dealing with national modelling of hydrology and macro-nutrient biogeochemistry. We evaluate the strategies needed to robustly benchmark our current predictive capability of these resources through ensemble modelling. We explore the use of catchment similarity concepts to understand if national monitoring programs can inform us about the behaviour of catchments. We discuss the challenges to applying these strategies in an open access and integrated framework and finally we consider the future for such virtual observatory platforms for improving the way we iteratively improve our understanding of catchment science.

Managing distributed software development in the Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Evans, Janet D.; Plante, Raymond L.; Boneventura, Nina; Busko, Ivo; Cresitello-Dittmar, Mark; D'Abrusco, Raffaele; Doe, Stephen; Ebert, Rick; Laurino, Omar; Pevunova, Olga; Refsdal, Brian; Thomas, Brian

2012-09-01

The U.S. Virtual Astronomical Observatory (VAO) is a product-driven organization that provides new scientific research capabilities to the astronomical community. Software development for the VAO follows a lightweight framework that guides development of science applications and infrastructure. Challenges to be overcome include distributed development teams, part-time efforts, and highly constrained schedules. We describe the process we followed to conquer these challenges while developing Iris, the VAO application for analysis of 1-D astronomical spectral energy distributions (SEDs). Iris was successfully built and released in less than a year with a team distributed across four institutions. The project followed existing International Virtual Observatory Alliance inter-operability standards for spectral data and contributed a SED library as a by-product of the project. We emphasize lessons learned that will be folded into future development efforts. In our experience, a well-defined process that provides guidelines to ensure the project is cohesive and stays on track is key to success. Internal product deliveries with a planned test and feedback loop are critical. Release candidates are measured against use cases established early in the process, and provide the opportunity to assess priorities and make course corrections during development. Also key is the participation of a stakeholder such as a lead scientist who manages the technical questions, advises on priorities, and is actively involved as a lead tester. Finally, frequent scheduled communications (for example a bi-weekly tele-conference) assure issues are resolved quickly and the team is working toward a common vision.

New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools (Corrigendum). I. UKIDSS LAS DR5 vs. SDSS DR7

NASA Astrophysics Data System (ADS)

Lodieu, N.; Espinoza Contreras, M.; Zapatero Osorio, M. R.; Solano, E.; Aberasturi, M.; Martín, E. L.

2017-01-01

Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 084.C-0928A.Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

A pseudoenergy wave-activity relation for ageostrophic and non-hydrostatic moist atmosphere

NASA Astrophysics Data System (ADS)

Ran, Ling-Kun; Ping, Fan

2015-05-01

By employing the energy-Casimir method, a three-dimensional virtual pseudoenergy wave-activity relation for a moist atmosphere is derived from a complete system of nonhydrostatic equations in Cartesian coordinates. Since this system of equations includes the effects of water substance, mass forcing, diabatic heating, and dissipations, the derived wave-activity relation generalizes the previous result for a dry atmosphere. The Casimir function used in the derivation is a monotonous function of virtual potential vorticity and virtual potential temperature. A virtual energy equation is employed (in place of the previous zonal momentum equation) in the derivation, and the basic state is stationary but can be three-dimensional or, at least, not necessarily zonally symmetric. The derived wave-activity relation is further used for the diagnosis of the evolution and propagation of meso-scale weather systems leading to heavy rainfall. Our diagnosis of two real cases of heavy precipitation shows that positive anomalies of the virtual pseudoenergy wave-activity density correspond well with the strong precipitation and are capable of indicating the movement of the precipitation region. This is largely due to the cyclonic vorticity perturbation and the vertically increasing virtual potential temperature over the precipitation region. Project supported by the National Basic Research Program of China (Grant No. 2013CB430105), the Key Program of the Chinese Academy of Sciences (Grant No. KZZD-EW-05), the National Natural Science Foundation of China (Grant No. 41175060), and the Project of CAMS, China (Grant No. 2011LASW-B15).

Relationship between Ripples and Gravity Waves Observed in OH Airglow over the Andes Lidar Observatory

NASA Astrophysics Data System (ADS)

Cao, B.; Gelinas, L. J.; Liu, A. Z.; Hecht, J. H.

2016-12-01

Instabilities generated by large amplitude gravity waves are ubiquitous in the mesopause region, and contribute to the strong forcing on the background atmosphere. Gravity waves and ripples generated by instability are commonly detected by high resolution airglow imagers that measure the hydroxyl emissions near the mesopause ( 87 km). Recently, a method based on 2D wavelet is developed by Gelinas et al. to characterize the statistics of ripple parameters from the Aerospace Infrared Camera at Andes Lidar Observatory located at Cerro Pachón, Chile (70.74°W, 30.25°S). In the meantime, data from a collocated all-sky imager is used to derive gravity wave parameters and their statistics. In this study, the relationship between the ripples and gravity waves that appeared at the same time and location are investigated in terms of their orientations, magnitudes and scales, to examine the statistical properties of the gravity wave induced instabilities and the ripples they generate.

Detecting stochastic backgrounds of gravitational waves with pulsar timing arrays

NASA Astrophysics Data System (ADS)

Siemens, Xavier

2016-03-01

For the past decade the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has been using the Green Bank Telescope and the Arecibo Observatory to monitor millisecond pulsars. NANOGrav, along with two other international collaborations, the European Pulsar Timing Array and the Parkes Pulsar Timing Array in Australia, form a consortium of consortia: the International Pulsar Timing Array (IPTA). The goal of the IPTA is to directly detect low-frequency gravitational waves which cause small changes to the times of arrival of radio pulses from millisecond pulsars. In this talk I will discuss the work of NANOGrav and the IPTA, as well as our sensitivity to stochastic backgrounds of gravitational waves. I will show that a detection of the background produced by supermassive black hole binaries is possible by the end of the decade. Supported by the NANOGrav Physics Frontiers Center.

Spotless Sun

NASA Image and Video Library

2017-03-20

NASA Solar Dynamics Observatory sees the sun has been virtually spotless, as in no sunspots, a 11-day spotless stretch not seen since the last solar minimum many years ago. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA21582

AVOCADO: A Virtual Observatory Census to Address Dwarfs Origins

NASA Astrophysics Data System (ADS)

Sánchez-Janssen, Rubén; Sánchez-Janssen

2011-12-01

Dwarf galaxies are by far the most abundant of all galaxy types, yet their properties are still poorly understood-especially due to the observational challenge that their intrinsic faintness represents. AVOCADO aims at establishing firm conclusions on their formation and evolution by constructing a homogeneous, multiwavelength dataset for a statistically significant sample of several thousand nearby dwarfs (-18 < Mi < -14). Using public data and Virtual Observatory tools, we have built GALEX+SDSS+2MASS spectral energy distributions that are fitted by a library of single stellar population models. Star formation rates, stellar masses, ages and metallicities are further complemented with structural parameters that can be used to classify them morphologically. This unique dataset, coupled with a detailed characterization of each dwarf's environment, allows for a fully comprehensive investigation of their origins and to track the (potential) evolutionary paths between the different dwarf types.

Digital data preservation for scholarly publications in astronomy

NASA Astrophysics Data System (ADS)

Choudhury, Sayeed; di Lauro, Tim; Szalay, Alex; Vishniac, Ethan; Hanisch, Robert; Steffen, Julie; Milkey, Robert; Ehling, Teresa; Plante, Ray

2007-11-01

Astronomy is similar to other scientific disciplines in that scholarly publication relies on the presentation and interpretation of data. But although astronomy now has archives for its primary research telescopes and associated surveys, the highly processed data that is presented in the peer-reviewed journals and is the basis for final analysis and interpretation is generally not archived and has no permanent repository. We have initiated a project whose goal is to implement an end-to-end prototype system which, through a partnership of a professional society, that society's scholarly publications/publishers, research libraries, and an information technology substrate provided by the Virtual Observatory, will capture high-level digital data as part of the publication process and establish a distributed network of curated, permanent data repositories. The data in this network will be accessible through the research journals, astronomy data centers, and Virtual Observatory data discovery portals.

Teaching astronomy and astrophysics at the Valencian International University (VIU): Application and use of Virtual Observatory tools

NASA Astrophysics Data System (ADS)

Diago, P. D.; Gutiérrez-Soto, J.; Ruiz, J. E.; Solano, E.

2013-05-01

The Astronomy and Astrophysics Master, running at the Valencian International University (VIU, http://www.viu.es) since march 2010, is a clear example of how development of infor- mation and communication technologies (ICTs) and new e-learning methods are changing the traditional distance learning. In the context of the European Space for Higher Edu- cation (ESHE) we present how the Virtual Observatory (VO) tools can be an important part in the Astronomy and Astrophysics teaching. The described tasks has been carried out during the last three courses. These tasks are representative of the state of the art in Astrophysics research. We attach a description and a learning results list of each one of the presented tasks. The tasks can be downloaded at the Spanish VO website: http://svo.cab.inta-csic.es/docs/index.php?pagename=Education/VOcases

Reprint of: Client interfaces to the Virtual Observatory Registry

NASA Astrophysics Data System (ADS)

Demleitner, M.; Harrison, P.; Taylor, M.; Normand, J.

2015-06-01

The Virtual Observatory Registry is a distributed directory of information systems and other resources relevant to astronomy. To make it useful, facilities to query that directory must be provided to humans and machines alike. This article reviews the development and status of such facilities, also considering the lessons learnt from about a decade of experience with Registry interfaces. After a brief outline of the history of the standards development, it describes the use of Registry interfaces in some popular clients as well as dedicated UIs for interrogating the Registry. It continues with a thorough discussion of the design of the two most recent Registry interface standards, RegTAP on the one hand and a full-text-based interface on the other hand. The article finally lays out some of the less obvious conventions that emerged in the interaction between providers of registry records and Registry users as well as remaining challenges and current developments.

Client interfaces to the Virtual Observatory Registry

NASA Astrophysics Data System (ADS)

Demleitner, M.; Harrison, P.; Taylor, M.; Normand, J.

2015-04-01

The Virtual Observatory Registry is a distributed directory of information systems and other resources relevant to astronomy. To make it useful, facilities to query that directory must be provided to humans and machines alike. This article reviews the development and status of such facilities, also considering the lessons learnt from about a decade of experience with Registry interfaces. After a brief outline of the history of the standards development, it describes the use of Registry interfaces in some popular clients as well as dedicated UIs for interrogating the Registry. It continues with a thorough discussion of the design of the two most recent Registry interface standards, RegTAP on the one hand and a full-text-based interface on the other hand. The article finally lays out some of the less obvious conventions that emerged in the interaction between providers of registry records and Registry users as well as remaining challenges and current developments.

WaveAR: A software tool for calculating parameters for water waves with incident and reflected components

NASA Astrophysics Data System (ADS)

Landry, Blake J.; Hancock, Matthew J.; Mei, Chiang C.; García, Marcelo H.

2012-09-01

The ability to determine wave heights and phases along a spatial domain is vital to understanding a wide range of littoral processes. The software tool presented here employs established Stokes wave theory and sampling methods to calculate parameters for the incident and reflected components of a field of weakly nonlinear waves, monochromatic at first order in wave slope and propagating in one horizontal dimension. The software calculates wave parameters over an entire wave tank and accounts for reflection, weak nonlinearity, and a free second harmonic. Currently, no publicly available program has such functionality. The included MATLAB®-based open source code has also been compiled for Windows®, Mac® and Linux® operating systems. An additional companion program, VirtualWave, is included to generate virtual wave fields for WaveAR. Together, the programs serve as ideal analysis and teaching tools for laboratory water wave systems.

Plans for a Next Generation Space-Based Gravitational-Wave Observatory (NGO)

NASA Technical Reports Server (NTRS)

Livas, Jeffrey C.; Stebbins, Robin T.; Jennrich, Oliver

2012-01-01

The European Space Agency (ESA) is currently in the process of selecting a mission for the Cosmic Visions Program. A space-based gravitational wave observatory in the low-frequency band (0.0001 - 1 Hz) of the gravitational wave spectrum is one of the leading contenders. This low frequency band has a rich spectrum of astrophysical sources, and the LISA concept has been the key mission to cover this science for over twenty years. Tight budgets have recently forced ESA to consider a reformulation of the LISA mission concept that wi" allow the Cosmic Visions Program to proceed on schedule either with the US as a minority participant, or independently of the US altogether. We report on the status of these reformulation efforts.

LigoDV-web: Providing easy, secure and universal access to a large distributed scientific data store for the LIGO scientific collaboration

NASA Astrophysics Data System (ADS)

Areeda, J. S.; Smith, J. R.; Lundgren, A. P.; Maros, E.; Macleod, D. M.; Zweizig, J.

2017-01-01

Gravitational-wave observatories around the world, including the Laser Interferometer Gravitational-Wave Observatory (LIGO), record a large volume of gravitational-wave output data and auxiliary data about the instruments and their environments. These data are stored at the observatory sites and distributed to computing clusters for data analysis. LigoDV-web is a web-based data viewer that provides access to data recorded at the LIGO Hanford, LIGO Livingston and GEO600 observatories, and the 40 m prototype interferometer at Caltech. The challenge addressed by this project is to provide meaningful visualizations of small data sets to anyone in the collaboration in a fast, secure and reliable manner with minimal software, hardware and training required of the end users. LigoDV-web is implemented as a Java Enterprise Application, with Shibboleth Single Sign On for authentication and authorization, and a proprietary network protocol used for data access on the back end. Collaboration members with proper credentials can request data be displayed in any of several general formats from any Internet appliance that supports a modern browser with Javascript and minimal HTML5 support, including personal computers, smartphones, and tablets. Since its inception in 2012, 634 unique users have visited the LigoDV-web website in a total of 33 , 861 sessions and generated a total of 139 , 875 plots. This infrastructure has been helpful in many analyses within the collaboration including follow-up of the data surrounding the first gravitational-wave events observed by LIGO in 2015.

On the Origin of the Solar Moreton Wave of 2006 December 6

DTIC Science & Technology

2010-11-01

Flight Center. Huntsville. AL 35812. USA 9 National Solar Observatory. Tucson, AZ 85719, USA 10 Faculty of Geodesy, University of Zagreb , Hvar...Observatory, HR 10000 Zagreb , Croatia 1’ Space Vehicles Directorate, Air Force Research Laboratory, Kirtland AFB, NM 87117, US A Received 2010 April 7

Europlanet/IDIS: Combining Diverse Planetary Observations and Models

NASA Astrophysics Data System (ADS)

Schmidt, Walter; Capria, Maria Teresa; Chanteur, Gerard

2013-04-01

Planetary research involves a diversity of research fields from astrophysics and plasma physics to atmospheric physics, climatology, spectroscopy and surface imaging. Data from all these disciplines are collected from various space-borne platforms or telescopes, supported by modelling teams and laboratory work. In order to interpret one set of data often supporting data from different disciplines and other missions are needed while the scientist does not always have the detailed expertise to access and utilize these observations. The Integrated and Distributed Information System (IDIS) [1], developed in the framework of the Europlanet-RI project, implements a Virtual Observatory approach ([2] and [3]), where different data sets, stored in archives around the world and in different formats, are accessed, re-formatted and combined to meet the user's requirements without the need of familiarizing oneself with the different technical details. While observational astrophysical data from different observatories could already earlier be accessed via Virtual Observatories, this concept is now extended to diverse planetary data and related model data sets, spectral data bases etc. A dedicated XML-based Europlanet Data Model (EPN-DM) [4] was developed based on data models from the planetary science community and the Virtual Observatory approach. A dedicated editor simplifies the registration of new resources. As the EPN-DM is a super-set of existing data models existing archives as well as new spectroscopic or chemical data bases for the interpretation of atmospheric or surface observations, or even modeling facilities at research institutes in Europe or Russia can be easily integrated and accessed via a Table Access Protocol (EPN-TAP) [5] adapted from the corresponding protocol of the International Virtual Observatory Alliance [6] (IVOA-TAP). EPN-TAP allows to search catalogues, retrieve data and make them available through standard IVOA tools if the access to the archive is compatible with IVOA standards. For some major data archives with different standards adaptation tools are available to make the access transparent to the user. EuroPlaNet-IDIS has contributed to the definition of PDAP, the Planetary Data Access Protocol of the International Planetary Data Alliance (IPDA) [7] to access the major planetary data archives of NASA in the USA [8], ESA in Europe [9] and JAXA in Japan [10]. Acknowledgement: Europlanet-RI was funded by the European Commission under the 7th Framework Program, grant 228319 "Capacities Specific Programme" - Research Infrastructures Action. Reference: [1] Details to IDIS and the Europlanet-RI via Web-site: http://www.idis.europlanet-ri.eu/ [2] Demonstrator implementation for Plasma-VO AMDA: http://cdpp-amda.cesr.fr/DDHTML/index.html [3] Demonstrator implementation for the IDIS-VO: http://www.idis-dyn.europlanet-ri.eu/vodev.shtml [4] Europlanet Data Model EPN-DM: http://www.europlanet-idis.fi/documents/public_documents/EPN-DM-v2.0.pdf [5] Europlanet Table Access Protocol EPN-TAP: http://www.europlanet-idis.fi/documents/public_documents/EPN-TAPV_0.26.pdf [6] International Virtual Observatory Alliance IVOA: http://www.ivoa.net [7] International Planetary Data Alliance IPDA: http://planetarydata.org/ [8] NASA's Planetary Data System: http://pds.jpl.nasa.gov/ [9] ESA's Planetary Science Archive PSA: http://www.sciops.esa.int/index.php?project=PSA [10] JAXAs Data Archive and Transmission System DARTS: http://darts.isas.jaxa.jp/

Semantically Enabling Knowledge Representation of Metamorphic Petrology Data

NASA Astrophysics Data System (ADS)

West, P.; Fox, P. A.; Spear, F. S.; Adali, S.; Nguyen, C.; Hallett, B. W.; Horkley, L. K.

2012-12-01

More and more metamorphic petrology data is being collected around the world, and is now being organized together into different virtual data portals by means of virtual organizations. For example, there is the virtual data portal Petrological Database (PetDB, http://www.petdb.org) of the Ocean Floor that is organizing scientific information about geochemical data of ocean floor igneous and metamorphic rocks; and also The Metamorphic Petrology Database (MetPetDB, http://metpetdb.rpi.edu) that is being created by a global community of metamorphic petrologists in collaboration with software engineers and data managers at Rensselaer Polytechnic Institute. The current focus is to provide the ability for scientists and researchers to register their data and search the databases for information regarding sample collections. What we present here is the next step in evolution of the MetPetDB portal, utilizing semantically enabled features such as discovery, data casting, faceted search, knowledge representation, and linked data as well as organizing information about the community and collaboration within the virtual community itself. We take the information that is currently represented in a relational database and make it available through web services, SPARQL endpoints, semantic and triple-stores where inferencing is enabled. We will be leveraging research that has taken place in virtual observatories, such as the Virtual Solar Terrestrial Observatory (VSTO) and the Biological and Chemical Oceanography Data Management Office (BCO-DMO); vocabulary work done in various communities such as Observations and Measurements (ISO 19156), FOAF (Friend of a Friend), Bibo (Bibliography Ontology), and domain specific ontologies; enabling provenance traces of samples and subsamples using the different provenance ontologies; and providing the much needed linking of data from the various research organizations into a common, collaborative virtual observatory. In addition to better representing and presenting the actual data, we also look to organize and represent the knowledge information and expertise behind the data. Domain experts hold a lot of knowledge in their minds, in their presentations and publications, and elsewhere. Not only is this a technical issue, this is also a social issue in that we need to be able to encourage the domain experts to share their knowledge in a way that can be searched and queried over. With this additional focus in MetPetDB the site can be used more efficiently by other domain experts, but can also be utilized by non-specialists as well in order to educate people of the importance of the work being done as well as enable future domain experts.

Bringing the Virtual Astronomical Observatory to the Education Community

NASA Astrophysics Data System (ADS)

Lawton, B.; Eisenhamer, B.; Mattson, B. J.; Raddick, M. J.

2012-08-01

The Virtual Observatory (VO) is an international effort to bring a large-scale electronic integration of astronomy data, tools, and services to the global community. The Virtual Astronomical Observatory (VAO) is the U.S. NSF- and NASA-funded VO effort that seeks to put efficient astronomical tools in the hands of U.S. astronomers, students, educators, and public outreach leaders. These tools will make use of data collected by the multitude of ground- and space-based missions over the previous decades. The Education and Public Outreach (EPO) program for the VAO will be led by the Space Telescope Science Institute in collaboration with the High Energy Astrophysics Science Archive Research Center (HEASARC) EPO program and Johns Hopkins University. VAO EPO efforts seek to bring technology, real-world astronomical data, and the story of the development and infrastructure of the VAO to the general public and education community. Our EPO efforts will be structured to provide uniform access to VAO information, enabling educational and research opportunities across multiple wavelengths and time-series data sets. The VAO team recognizes that the VO has already built many tools for EPO purposes, such as Microsoft's World Wide Telescope, SDSS Sky Server, Aladin, and a multitude of citizen-science tools available from Zooniverse. However, it is not enough to simply provide tools. Tools must meet the needs of the education community and address national education standards in order to be broadly utilized. To determine which tools the VAO will incorporate into the EPO program, needs assessments will be conducted with educators across the U.S.

VObs.it, the Italian contribution to the international Virtual Observatory-History, activities, strategy

NASA Astrophysics Data System (ADS)

Pasian, F.

2015-06-01

The origins of the Italian contribution to the international Virtual Observatory (VO) were mainly tied to the definition and implementation of a Data Grid using Grid standards. From there on, by means of a step-wise evolution, activities started including the implementation of VO-aware tools and facilities, or the production of services accessing data archives in ways compliant to the international VO standards. An important activity the Italian VO community has carried out is the dissemination of the VO capabilities to professionals, students and amateurs: in particular, an important and maybe unique success has been bringing to the classrooms the VO, and using it as a powerful tool to teach astronomy at all levels, from junior high school to undergraduate courses. Lately, there has been also direct involvement of the Italian community in the definition of standards and services within the framework of the International Virtual Observatory Alliance (IVOA), and participation and leadership in the IVOA Working Groups. Along this path, the national funding for these activities has been rather low, although essential to carry the activities on. There were no bursts of funding to allow a quick rise in activities leading to the fast realisation of tools and systems. Rather, the manpower involved in VObs.it has been always fairly low but steady. In the view of managing a national VO initiative with a low budget, strategic choices were made to exploit the available resources and to guarantee a constant background activity, mainly geared at providing services to the community, development in lower-priority VO areas, dissemination and support.

The Virtual World Presence of the International Year of Astronomy 2009

NASA Astrophysics Data System (ADS)

Gauthier, Adrienne J.; Huber, D.; Gay, P. L.; New Media Task Group IYA2009

2010-01-01

From January 2009 to January 2010, the virtual celebration of the International Year of Astronomy 2009 has come full circle side-by-side with the real world celebrations. Throughout the year, the 'Astronomy 2009' island promoted the IYA2009 within the virtual world of Second Life(R) with the goal to engage and inspire the general public in astronomy. This island is situated in the group area called SciLands, a science and technology focused mini-continent of over 60 islands. We are host to immersive exhibits for the real life projects: From Earth to the Universe, The World at Night, Dark Skies Awareness, Let There Be Night, IAAA The Artists' Universe, 365 Days of Astronomy podcast, Spitzer's MIPSGAL/GLIMPSE walkable image, and Adler Planetarium's Far Out Fridays lecture series. Spitzer Space Telescope, Chandra X-ray Observatory, and the Hubble Heritage project provided over 300 free textures in a gift pack to visitors. Other exhibits include a replica of the Lord Rosse Leviathan telescope, an astrophotography grotto featuring Adam Block, David Malin, and John Gleason's work, a functional planetarium donated by Rob Knop, and live star party events from Chico Observatory. We'll review the exhibits and live events presented throughout the past year and speak towards the plans for the future. Formative evaluation strategies and first impressions of the summative evaluation of the first year of the project will be presented. Special thanks to our sponsors: Interstellar Studios/400 Years of the Telescope, Department of Astronomy University of Arizona, Spitzer Space Telescope, Chandra X-Ray Observatory, and Helio Huet.

Las Cumbres Observatory Followup of Gravitational Waves - Part 3

NASA Astrophysics Data System (ADS)

McCully, Curtis; Arcavi, Iair; Howell, D. Andrew

2018-01-01

Las Cumbres Observatory (LCO) is a unique followup facility for gravitational-wave detections. It consists of 20 telescopes at 6 sites around the world, working as one robotic, dynamically scheduled global network. This has proven to be extremely useful for gravitational-wave followup during observing run 2 (O2). Given the robotic nature of our network, we are capable of receiving gravitational wave alerts, selecting and prioritizing galaxies to be observed in the localization region, and submitting the observations to the LCO scheduler - all within seconds. Observations can then begin within minutes. We will present our experience employing this strategy during O2, as well as the extensive followup data obtained for one of the triggers. This is talk 3 in a series of three talks (the details of the division of topics between these three talks is embargoed at the time of abstract submission).

Las Cumbres Observatory Followup of Gravitational Waves - Part 1

NASA Astrophysics Data System (ADS)

Arcavi, Iair; Howell, D. Andrew; McCully, Curtis

2018-01-01

Las Cumbres Observatory (LCO) is a unique followup facility for gravitational-wave detections. It consists of 20 telescopes at 6 sites around the world, working as one robotic, dynamically scheduled global network. This has proven to be extremely useful for gravitational-wave followup during observing run 2 (O2). Given the robotic nature of our network, we are capable of receiving gravitational wave alerts, selecting and prioritizing galaxies to be observed in the localization region, and submitting the observations to the LCO scheduler - all within seconds. Observations can then begin within minutes. We will present our experience employing this strategy during O2, as well as the extensive followup data obtained for one of the triggers. This is talk 1 in a series of three talks (the details of the division of topics between these three talks is embargoed at the time of abstract submission).

Las Cumbres Observatory Followup of Gravitational Waves - Part 2

NASA Astrophysics Data System (ADS)

Howell, D. Andrew; Arcavi, Iair; McCully, Curtis

2018-01-01

Las Cumbres Observatory (LCO) is a unique followup facility for gravitational-wave detections. It consists of 20 telescopes at 6 sites around the world, working as one robotic, dynamically scheduled global network. This has proven to be extremely useful for gravitational-wave followup during observing run 2 (O2). Given the robotic nature of our network, we are capable of receiving gravitational wave alerts, selecting and prioritizing galaxies to be observed in the localization region, and submitting the observations to the LCO scheduler - all within seconds. Observations can then begin within minutes. We will present our experience employing this strategy during O2, as well as the extensive followup data obtained for one of the triggers. This is talk 2 in a series of three talks (the details of the division of topics between these three talks is embargoed at the time of abstract submission).

Special issue on enabling open and interoperable access to Planetary Science and Heliophysics databases and tools

NASA Astrophysics Data System (ADS)

2018-01-01

The large amount of data generated by modern space missions calls for a change of organization of data distribution and access procedures. Although long term archives exist for telescopic and space-borne observations, high-level functions need to be developed on top of these repositories to make Planetary Science and Heliophysics data more accessible and to favor interoperability. Results of simulations and reference laboratory data also need to be integrated to support and interpret the observations. Interoperable software and interfaces have recently been developed in many scientific domains. The Virtual Observatory (VO) interoperable standards developed for Astronomy by the International Virtual Observatory Alliance (IVOA) can be adapted to Planetary Sciences, as demonstrated by the VESPA (Virtual European Solar and Planetary Access) team within the Europlanet-H2020-RI project. Other communities have developed their own standards: GIS (Geographic Information System) for Earth and planetary surfaces tools, SPASE (Space Physics Archive Search and Extract) for space plasma, PDS4 (NASA Planetary Data System, version 4) and IPDA (International Planetary Data Alliance) for planetary mission archives, etc, and an effort to make them interoperable altogether is starting, including automated workflows to process related data from different sources.

Advanced Gravitational Wave Detectors

NASA Astrophysics Data System (ADS)

Blair, D. G.; Howell, E. J.; Ju, L.; Zhao, C.

2012-02-01

Part I. An Introduction to Gravitational Wave Astronomy and Detectors: 1. Gravitational waves D. G. Blair, L. Ju, C. Zhao and E. J. Howell; 2. Sources of gravitational waves D. G. Blair and E. J. Howell; 3. Gravitational wave detectors D. G. Blair, L. Ju, C. Zhao, H. Miao, E. J. Howell, and P. Barriga; 4. Gravitational wave data analysis B. S. Sathyaprakash and B. F. Schutz; 5. Network analysis L. Wen and B. F. Schutz; Part II. Current Laser Interferometer Detectors: Three Case Studies: 6. The Laser Interferometer Gravitational-Wave Observatory P. Fritschel; 7. The VIRGO detector S. Braccini; 8. GEO 600 H. Lück and H. Grote; Part III. Technology for Advanced Gravitational Wave Detectors: 9. Lasers for high optical power interferometers B. Willke and M. Frede; 10. Thermal noise, suspensions and test masses L. Ju, G. Harry and B. Lee; 11. Vibration isolation: Part 1. Seismic isolation for advanced LIGO B. Lantz; Part 2. Passive isolation J-C. Dumas; 12. Interferometer sensing and control P. Barriga; 13. Stabilizing interferometers against high optical power effects C. Zhao, L. Ju, S. Gras and D. G. Blair; Part IV. Technology for Third Generation Gravitational Wave Detectors: 14. Cryogenic interferometers J. Degallaix; 15. Quantum theory of laser-interferometer GW detectors H. Miao and Y. Chen; 16. ET. A third generation observatory M. Punturo and H. Lück; Index.

Spacelab

NASA Image and Video Library

1990-12-05

This image shows a part of the Cygnus loop supernova remnant, taken by the Ultraviolet Imaging Telescope (UIT) on the Astro Observatory during the Astro-1 mission (STS-35) on December 5, 1990. Pictured is a portion of the huge Cygnus loop, an array of interstellar gas clouds that have been blasted by a 900,000 mile per hour shock wave from a prehistoric stellar explosion, which occurred about 20,000 years ago, known as supernova. With ultraviolet and x-rays, astronomers can see emissions from extremely hot gases, intense magnetic fields, and other high-energy phenomena that more faintly appear in visible and infrared light or in radio waves that are crucial to deepening the understanding of the universe. The Astro Observatory was designed to explore the universe by observing and measuring the ultraviolet radiation from celestial objects. Three instruments make up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had managment responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

Computer Vision for the Solar Dynamics Observatory (SDO)

NASA Astrophysics Data System (ADS)

Martens, P. C. H.; Attrill, G. D. R.; Davey, A. R.; Engell, A.; Farid, S.; Grigis, P. C.; Kasper, J.; Korreck, K.; Saar, S. H.; Savcheva, A.; Su, Y.; Testa, P.; Wills-Davey, M.; Bernasconi, P. N.; Raouafi, N.-E.; Delouille, V. A.; Hochedez, J. F.; Cirtain, J. W.; Deforest, C. E.; Angryk, R. A.; de Moortel, I.; Wiegelmann, T.; Georgoulis, M. K.; McAteer, R. T. J.; Timmons, R. P.

2012-01-01

In Fall 2008 NASA selected a large international consortium to produce a comprehensive automated feature-recognition system for the Solar Dynamics Observatory (SDO). The SDO data that we consider are all of the Atmospheric Imaging Assembly (AIA) images plus surface magnetic-field images from the Helioseismic and Magnetic Imager (HMI). We produce robust, very efficient, professionally coded software modules that can keep up with the SDO data stream and detect, trace, and analyze numerous phenomena, including flares, sigmoids, filaments, coronal dimmings, polarity inversion lines, sunspots, X-ray bright points, active regions, coronal holes, EIT waves, coronal mass ejections (CMEs), coronal oscillations, and jets. We also track the emergence and evolution of magnetic elements down to the smallest detectable features and will provide at least four full-disk, nonlinear, force-free magnetic field extrapolations per day. The detection of CMEs and filaments is accomplished with Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) and ground-based Hα data, respectively. A completely new software element is a trainable feature-detection module based on a generalized image-classification algorithm. Such a trainable module can be used to find features that have not yet been discovered (as, for example, sigmoids were in the pre- Yohkoh era). Our codes will produce entries in the Heliophysics Events Knowledgebase (HEK) as well as produce complete catalogs for results that are too numerous for inclusion in the HEK, such as the X-ray bright-point metadata. This will permit users to locate data on individual events as well as carry out statistical studies on large numbers of events, using the interface provided by the Virtual Solar Observatory. The operations concept for our computer vision system is that the data will be analyzed in near real time as soon as they arrive at the SDO Joint Science Operations Center and have undergone basic processing. This will allow the system to produce timely space-weather alerts and to guide the selection and production of quicklook images and movies, in addition to its prime mission of enabling solar science. We briefly describe the complex and unique data-processing pipeline, consisting of the hardware and control software required to handle the SDO data stream and accommodate the computer-vision modules, which has been set up at the Lockheed-Martin Space Astrophysics Laboratory (LMSAL), with an identical copy at the Smithsonian Astrophysical Observatory (SAO).

Retrieval of reflections from ambient noise using illumination diagnosis

NASA Astrophysics Data System (ADS)

Vidal, C. Almagro; Draganov, D.; van der Neut, J.; Drijkoningen, G.; Wapenaar, K.

2014-09-01

Seismic interferometry (SI) enables the retrieval of virtual sources at the location of receivers. In the case of passive SI, no active sources are used for the retrieval of the reflection response of the subsurface, but ambient-noise recordings only. The resulting retrieved response is determined by the illumination characteristics of the recorded ambient noise. Characteristics like geometrical distribution and signature of the noise sources, together with the complexity of the medium and the length of the noise records, determine the quality of the retrieved virtual-shot events. To retrieve body wave reflections, one needs to correlate body-wave noise. A source of such noise might be regional seismicity. In regions with notable human presence, the dominant noise sources are generally located at or close to the surface. In the latter case, the noise will be dominated by surface waves and consequently also the retrieved virtual common-source panels will contain dominant retrieved surface waves, drowning out possible retrieved reflections. In order to retrieve reflection events, suppression of the surface waves becomes the most important pre-processing goal. Because of the reasons mentioned above, we propose a fast method to evaluate the illumination characteristics of ambient noise using the correlation results from ambient-noise records. The method is based on the analysis of the so-called source function of the retrieved virtual-shot panel, and evaluates the apparent slowness of arrivals in the correlation results that pass through the position of the virtual source and at zero time. The results of the diagnosis are used to suppress the retrieval of surface waves and therefore to improve the quality of the retrieved reflection response. We explain the approach using modelled data from transient and continuous noise sources and an example from a passive field data set recorded at Annerveen, Northern Netherlands.

Predictions for Swift Follow-up Observations of Advanced LIGO/Virgo Gravitational Wave Sources

NASA Astrophysics Data System (ADS)

Racusin, Judith; Evans, Phil; Connaughton, Valerie

2015-04-01

The likely detection of gravitational waves associated with the inspiral of neutron star binaries by the upcoming advanced LIGO/Virgo observatories will be complemented by searches for electromagnetic counterparts over large areas of the sky by Swift and other observatories. As short gamma-ray bursts (GRB) are the most likely electromagnetic counterpart candidates to these sources, we can make predictions based upon the last decade of GRB observations by Swift and Fermi. Swift is uniquely capable of accurately localizing new transients rapidly over large areas of the sky in single and tiled pointings, enabling ground-based follow-up. We describe simulations of the detectability of short GRB afterglows by Swift given existing and hypothetical tiling schemes with realistic observing conditions and delays, which guide the optimal observing strategy and improvements provided by coincident detection with observatories such as Fermi-GBM.

Integrating the IA2 Astronomical Archive in the VO: The VO-Dance Engine

NASA Astrophysics Data System (ADS)

Molinaro, M.; Laurino, O.; Smareglia, R.

2012-09-01

Virtual Observatory (VO) protocols and standards are getting mature and the astronomical community asks for astrophysical data to be easily reachable. This means data centers have to intensify their efforts to provide the data they manage not only through proprietary portals and services but also through interoperable resources developed on the basis of the IVOA (International Virtual Observatory Alliance) recommendations. Here we present the work and ideas developed at the IA2 (Italian Astronomical Archive) data center hosted by the INAF-OATs (Italian Institute for Astrophysics - Trieste Astronomical Observatory) to reach this goal. The core point is the development of an application that from existing DB and archive structures can translate their content to VO compliant resources: VO-Dance (written in Java). This application, in turn, relies on a database (potentially DBMS independent) to store the translation layer information of each resource and auxiliary content (UCDs, field names, authorizations, policies, etc.). The last token is an administrative interface (currently developed using the Django python framework) to allow the data center administrators to set up and maintain resources. This deployment, platform independent, with database and administrative interface highly customizable, means the package, when stable and easily distributable, can be also used by single astronomers or groups to set up their own resources from their public datasets.

Well-defined EUV wave associated with a CME-driven shock

NASA Astrophysics Data System (ADS)

Cunha-Silva, R. D.; Selhorst, C. L.; Fernandes, F. C. R.; Oliveira e Silva, A. J.

2018-05-01

Aims: We report on a well-defined EUV wave observed by the Extreme Ultraviolet Imager (EUVI) on board the Solar Terrestrial Relations Observatory (STEREO) and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). The event was accompanied by a shock wave driven by a halo CME observed by the Large Angle and Spectrometric Coronagraph (LASCO-C2/C3) on board the Solar and Heliospheric Observatory (SOHO), as evidenced by the occurrence of type II bursts in the metric and dekameter-hectometric wavelength ranges. We investigated the kinematics of the EUV wave front and the radio source with the purpose of verifying the association between the EUV wave and the shock wave. Methods: The EUV wave fronts were determined from the SDO/AIA images by means of two appropriate directions (slices). The heights (radial propagation) of the EUV wave observed by STEREO/EUVI and of the radio source associated with the shock wave were compared considering the whole bandwidth of the harmonic lane of the radio emission, whereas the speed of the shock was estimated using the lowest frequencies of the harmonic lane associated with the undisturbed corona, using an appropriate multiple of the Newkirk (1961, ApJ, 133, 983) density model and taking into account the H/F frequency ratio fH/fF = 2. The speed of the radio source associated with the interplanetary shock was determined using the Mann et al. (1999, A&A, 348, 614) density model. Results: The EUV wave fronts determined from the SDO/AIA images revealed the coexistence of two types of EUV waves, a fast one with a speed of 560 km s-1, and a slower one with a speed of 250 km s-1, which corresponds approximately to one-third of the average speed of the radio source ( 680 km s-1). The radio signature of the interplanetary shock revealed an almost constant speed of 930 km s-1, consistent with the linear speed of the halo CME (950 km s-1) and with the values found for the accelerating coronal shock ( 535-823 km s-1), taking into account the gap between the radio emissions.

Atomic Interferometric Gravitational-Wave Space Observatory (AIGSO)

NASA Astrophysics Data System (ADS)

Gao, Dong-Feng; Wang, Jin; Zhan, Ming-Sheng

2018-01-01

We propose a space-borne gravitational-wave detection scheme, called atom interferometric gravitational-wave space observatory (AIGSO). It is motivated by the progress in the atomic matter-wave interferometry, which solely utilizes the standing light waves to split, deflect and recombine the atomic beam. Our scheme consists of three drag-free satellites orbiting the Earth. The phase shift of AIGSO is dominated by the Sagnac effect of gravitational-waves, which is proportional to the area enclosed by the atom interferometer, the frequency and amplitude of gravitational-waves. The scheme has a strain sensitivity < {10}-20/\\sqrt{{Hz}} in the 100 mHz-10 Hz frequency range, which fills in the detection gap between space-based and ground-based laser interferometric detectors. Thus, our proposed AIGSO can be a good complementary detection scheme to the space-borne laser interferometric schemes, such as LISA. Considering the current status of relevant technology readiness, we expect our AIGSO to be a promising candidate for the future space-based gravitational-wave detection plan. Supported by the National Key Research Program of China under Grant No. 2016YFA0302002, the National Science Foundation of China under Grant Nos. 11227803 and 91536221, and the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No. XDB21010100

“Dandelion” Filament Eruption and Coronal Waves Associated with a Solar Flare on 2011 February 16

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cabezas, Denis P.; Ishitsuka, Mutsumi; Ishitsuka, José K.

Coronal disturbances associated with solar flares, such as H α Moreton waves, X-ray waves, and extreme ultraviolet (EUV) coronal waves, are discussed herein in relation to magnetohydrodynamic fast-mode waves or shocks in the corona. To understand the mechanism of coronal disturbances, full-disk solar observations with high spatial and temporal resolution over multiple wavelengths are of crucial importance. We observed a filament eruption, whose shape is like a “dandelion,” associated with the M1.6 flare that occurred on 2011 February 16 in H α images taken by the Flare Monitoring Telescope at Ica University, Peru. We derive the three-dimensional velocity field ofmore » the erupting filament. We also identify winking filaments that are located far from the flare site in the H α images, whereas no Moreton wave is observed. By comparing the temporal evolution of the winking filaments with those of the coronal wave seen in the EUV images data taken by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory and by the Extreme Ultraviolet Imager on board the Solar Terrestrial Relations Observatory-Ahead , we confirm that the winking filaments were activated by the EUV coronal wave.« less

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1959-01-01

This image is of the Crab Nebula in visible light photographed by the Hale Observatory optical telescope in 1959. The faint object at the center had been identified as a pulsar and is thought to be the remains of the original star. It had been observed as a pulsar in visible light, radio wave, x-rays, and gamma-rays.

Autoplot: a Browser for Science Data on the Web

NASA Astrophysics Data System (ADS)

Faden, J.; Weigel, R. S.; West, E. E.; Merka, J.

2008-12-01

Autoplot (www.autoplot.org) is software for plotting data from many different sources and in many different file formats. Data from CDF, CEF, Fits, NetCDF, and OpenDAP can be plotted, along with many other sources such as ASCII tables and Excel spreadsheets. This is done by adapting these various data formats and APIs into a common data model that borrows from the netCDF and CDF data models. Autoplot uses a web browser metaphor to simplify use. The user specifies a parameter URL, for example a CDF file accessible via http with a parameter name appended, and the file resource is downloaded and the parameter is rendered in a scientifically meaningful way. When data span multiple files, the user can use a file name template in the URL to aggregate (combine) a set of remote files. So the problem of aggregating data across file boundaries is handled on the client side, allowing simple web servers to be used. The das2 graphics library provides rich controls for exploring the data. Scripting is supported through Python, providing not just programmatic control, but for calculating new parameters in a language that will look familiar to IDL and Matlab users. Autoplot is Java-based software, and will run on most computers without a burdensome installation process. It can also used as an applet or as a servlet that serves static images. Autoplot was developed as part of the Virtual Radiation Belt Observatory (ViRBO) project, and is also being used for the Virtual Magnetospheric Observatory (VMO). It is expected that this flexible, general-purpose plotting tool will be useful for allowing a data provider to add instant visualization capabilities to a directory of files or for general use in the Virtual Observatory environment.

Education and Outreach with the Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Lawton, Brandon L.; Eisenhamer, B.; Raddick, M. J.; Mattson, B. J.; Harris, J.

2012-01-01

The Virtual Observatory (VO) is an international effort to bring a large-scale electronic integration of astronomy data, tools, and services to the global community. The Virtual Astronomical Observatory (VAO) is the U.S. NSF- and NASA-funded VO effort that seeks to put efficient astronomical tools in the hands of U.S. astronomers, students, educators, and public outreach leaders. These tools will make use of data collected by the multitude of ground- and space-based missions over the previous decades. Many future missions will also be incorporated into the VAO tools when they launch. The Education and Public Outreach (E/PO) program for the VAO is led by the Space Telescope Science Institute in collaboration with the HEASARC E/PO program and Johns Hopkins University. VAO E/PO efforts seek to bring technology, real-world astronomical data, and the story of the development and infrastructure of the VAO to the general public, formal education, and informal education communities. Our E/PO efforts will be structured to provide uniform access to VAO information, enabling educational opportunities across multiple wavelengths and time-series data sets. The VAO team recognizes that many VO programs have built powerful tools for E/PO purposes, such as Microsoft's World Wide Telescope, SDSS Sky Server, Aladin, and a multitude of citizen-science tools available from Zooniverse. We are building partnerships with Microsoft, Zooniverse, and NASA's Night Sky Network to leverage the communities and tools that already exist to meet the needs of our audiences. Our formal education program is standards-based and aims to give teachers the tools to use real astronomical data to teach the STEM subjects. To determine which tools the VAO will incorporate into the formal education program, needs assessments will be conducted with educators across the U.S.

Towards a virtual observatory for ecosystem services and poverty alleviation

NASA Astrophysics Data System (ADS)

Buytaert, W.; Baez, S.; Cuesta, F.; Veliz Rosas, C.

2010-12-01

Over the last decades, near real-time environmental observation, technical advances in computer power and cyber-infrastructure, and the development of environmental software algorithms have increased dramatically. The integration of these evolutions, which is commonly referred to as the establishment of a virtual observatory, is one of the major challenges of the next decade for environmental sciences. Worldwide, many coordinated activities are ongoing to make this integration a reality. However, far less attention is paid to the question of how these developments can benefit environmental services management in a poverty alleviation context. Such projects are typically faced with issues of large predictive uncertainties, limited resources, limited local scientific capacity. At the same time, the complexity of the socio-economic contexts requires a very strong bottom-up oriented and interdisciplinary approach to environmental data collection and processing. In this study, we present three natural resources management cases in the Andes and the Amazon basin, and investigate how "virtual observatory" technology can improve ecosystem management. Each of these case studies present scientific challenges in terms of model coupling, real-time data assimilation and visualisation for management purposes. The first project deals with water resources management in the Peruvian Andes. Using a rainfall-runoff model, novel visualisations are used to give farmers insight in the water production and regulation capacity of their catchments, which can then be linked to land management practices such as conservation agriculture, wetland protection and grazing density control. In a project in the Amazonian floodplains, optimal allocation of the nesting availability and quality of the giant freshwater turtle are determined using a combined hydraulic model and weather forecasts. Finally, in the rainforest of the Yasuní Biosphere Reserve, Ecuador, biodiversity models are used to quantify the impacts of hunting and logging on community composition and wildlife populations.

The Heliophysics Data Environment, Virtual Observatories, NSSDC, and SPASE

NASA Technical Reports Server (NTRS)

Thieman, James; Grayzeck, Edwin; Roberts, Aaron; King, Todd

2010-01-01

Heliophysics (the study of the Sun and its effects on the Solar System, especially the Earth) has an interesting data environment in that the data are often to be found in relatively small data sets widely scattered in archives around the world. Within the last decade there have been more concentrated efforts to organize the data access methods and create a Heliophysics Data and Model Consortium (HDMC). To provide data search and access capability a number of Virtual Observatories (VO's) have been established both via funding from the U.S. National Aeronautics and Space Administration (NASA) and through other funding agencies in the U.S. and worldwide. At least 15 systems can be labeled as Heliophysics Virtual Observatories, 9 of them funded by NASA. Other parts of this data environment include Resident Archives, and the final, or "deep" archive at the National Space Science Data Center (NSSDC). The problem is that different data search and access approaches are used by all of these elements of the HDMC and a search for data relevant to a particular research question can involve consulting with multiple VO's - needing to learn a different approach for finding and acquiring data for each. The Space Physics Archive Search and Extract (SPASE) project is intended to provide a common data model for Heliophysics data and therefore a common set of metadata for searches of the VO's and other data environment elements. The SPASE Data Model has been developed through the common efforts of the HDMC representatives over a number of years. We currently have released Version 2.1. of the Data Model. The advantages and disadvantages of the Data Model will be discussed along with the plans for the future. Recent changes requested by new members of the SPASE community indicate some of the directions for further development.

Code Sharing and Collaboration: Experiences from the Scientist's Expert Assistant Project and their Relevance to the Virtual Observatory

NASA Technical Reports Server (NTRS)

Jones, Jeremy; Grosvenor, Sandy; Wolf, Karl; Li, Connie; Koratkar, Anuradha; Powers, Edward I. (Technical Monitor)

2001-01-01

In the Virtual Observatory (VO), software tools will perform the functions that have traditionally been performed by physical observatories and their instruments. These tools will not be adjuncts to VO functionality but will make up the very core of the VO. Consequently, the tradition of observatory and system independent tools serving a small user base is not valid for the VO. For the VO to succeed, we must improve software collaboration and code sharing between projects and groups. A significant goal of the Scientist's Expert Assistant (SEA) project has been promoting effective collaboration and code sharing between groups. During the past three years, the SEA project has been developing prototypes for new observation planning software tools and strategies. Initially funded by the Next Generation Space Telescope, parts of the SEA code have since been adopted by the Space Telescope Science Institute. SEA has also supplied code for SOFIA, the SIRTF planning tools, and the JSky Open Source Java library. The potential benefits of sharing code are clear. The recipient gains functionality for considerably less cost. The provider gains additional developers working with their code. If enough users groups adopt a set of common code and tools, defacto standards can emerge (as demonstrated by the success of the FITS standard). Code sharing also raises a number of challenges related to the management of the code. In this talk, we will review our experiences with SEA - both successes and failures - and offer some lessons learned that may promote further successes in collaboration and re-use.

Code Sharing and Collaboration: Experiences From the Scientist's Expert Assistant Project and Their Relevance to the Virtual Observatory

NASA Technical Reports Server (NTRS)

Korathkar, Anuradha; Grosvenor, Sandy; Jones, Jeremy; Li, Connie; Mackey, Jennifer; Neher, Ken; Obenschain, Arthur F. (Technical Monitor)

2001-01-01

In the Virtual Observatory (VO), software tools will perform the functions that have traditionally been performed by physical observatories and their instruments. These tools will not be adjuncts to VO functionality but will make up the very core of the VO. Consequently, the tradition of observatory and system independent tools serving a small user base is not valid for the VO. For the VO to succeed, we must improve software collaboration and code sharing between projects and groups. A significant goal of the Scientist's Expert Assistant (SEA) project has been promoting effective collaboration and code sharing among groups. During the past three years, the SEA project has been developing prototypes for new observation planning software tools and strategies. Initially funded by the Next Generation Space Telescope, parts of the SEA code have since been adopted by the Space Telescope Science Institute. SEA has also supplied code for the SIRTF (Space Infrared Telescope Facility) planning tools, and the JSky Open Source Java library. The potential benefits of sharing code are clear. The recipient gains functionality for considerably less cost. The provider gains additional developers working with their code. If enough users groups adopt a set of common code and tools, de facto standards can emerge (as demonstrated by the success of the FITS standard). Code sharing also raises a number of challenges related to the management of the code. In this talk, we will review our experiences with SEA--both successes and failures, and offer some lessons learned that might promote further successes in collaboration and re-use.

Search for gravitational waves from compact binary coalescence in LIGO and Virgo data from S5 and VSR1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abadie, J.; Abbott, B. P.; Abbott, R.

We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-Wave Observatory and Virgo detectors. Five months of data were collected during the Laser Interferometer Gravitational-Wave Observatory's S5 and Virgo's VSR1 science runs. The search focused on signals from binary mergers with a total mass between 2 and 35M{sub {center_dot}}. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for nonspinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7x10{sup -3} yr{sup -1} L{submore » 10}{sup -1}, 2.2x10{sup -3} yr{sup -1} L{sub 10}{sup -1}, and 4.4x10{sup -4} yr{sup -1} L{sub 10}{sup -1}, respectively, where L{sub 10} is 10{sup 10} times the blue solar luminosity. These upper limits are compared with astrophysical expectations.« less

Charge management for gravitational-wave observatories using UV LEDs

NASA Astrophysics Data System (ADS)

Pollack, S. E.; Turner, M. D.; Schlamminger, S.; Hagedorn, C. A.; Gundlach, J. H.

2010-01-01

Accumulation of electrical charge on the end mirrors of gravitational-wave observatories can become a source of noise limiting the sensitivity of such detectors through electronic couplings to nearby surfaces. Torsion balances provide an ideal means for testing gravitational-wave technologies due to their high sensitivity to small forces. Our torsion pendulum apparatus consists of a movable plate brought near a plate pendulum suspended from a nonconducting quartz fiber. A UV LED located near the pendulum photoejects electrons from the surface, and a UV LED driven electron gun directs photoelectrons towards the pendulum surface. We have demonstrated both charging and discharging of the pendulum with equivalent charging rates of ˜105e/s, as well as spectral measurements of the pendulum charge resulting in a white noise level equivalent to 3×105e/Hz.

Virtual plane-wave imaging via Marchenko redatuming

NASA Astrophysics Data System (ADS)

Meles, Giovanni Angelo; Wapenaar, Kees; Thorbecke, Jan

2018-04-01

Marchenko redatuming is a novel scheme used to retrieve up- and down-going Green's functions in an unknown medium. Marchenko equations are based on reciprocity theorems and are derived on the assumption of the existence of functions exhibiting space-time focusing properties once injected in the subsurface. In contrast to interferometry but similarly to standard migration methods, Marchenko redatuming only requires an estimate of the direct wave from the virtual source (or to the virtual receiver), illumination from only one side of the medium, and no physical sources (or receivers) inside the medium. In this contribution we consider a different time-focusing condition within the frame of Marchenko redatuming that leads to the retrieval of virtual plane-wave responses. As a result, it allows multiple-free imaging using only a one-dimensional sampling of the targeted model at a fraction of the computational cost of standard Marchenko schemes. The potential of the new method is demonstrated on 2D synthetic models.

CosmoQuest - Scientist Engagement with the Public and Schools via a Virtual Research Facility

NASA Astrophysics Data System (ADS)

Noel-Storr, Jacob; Buxner, Sanlyn; Gay, Pamela L.; Grier, Jennifer A.; Lehan, Cory; CosmoQuest Team

2016-06-01

CosmoQuest is a virtual research facility where science data can be analyzed by teams of interested citizen scientists from across the world. Scientists can apply to have their data analyzed through crowdsourcing in our online observatory, which generates validated and publishable results (Robbins et al 2014). Scientists have the opportunity to provide connections to teachers in classrooms so that students can analyze original data and understand the process that astronomers go through from image to result. Scientists can also teach online classes for different audiences including formal classroom teachers, informal educators, and lifelong learners to further the broader impacts of their work and increase engagement in their scientific endeavors. We provide training, through online and in-person workshops, on how to incorporate your datasets into the observatory and how to deliver online classes through our CosmoAcademy. This work is funded in part by NASA Cooperative Agreement Notice number NNX16AC68A. For more information, visit http://cosmoquest.org/.

Web Services for Astronomical Databases: Connecting AIPS++ to the Virtual Observatory

NASA Astrophysics Data System (ADS)

Douthit, M. C.

2002-12-01

In the year 2010, the NRAO will be operating four of the world's most powerful radio telescopes: GBT, EVLA, VLBA, and ALMA (with international partnership). Multi-Terabyte data sets will quickly accumulate with a rate of twenty-five to fifty Megabytes of data per second generated by ALMA and EVLA each. It will be imperative for scientists to possess software capable of automated data reduction, image synthesis, and archiving. With the evolution of AIPS++ and the recently developed concepts of the image pipeline, the participation of the NRAO in the virtual observatories of the future is now on the horizon giving birth to the need for fast archive access and web service development in AIPS++. When the software package began over 10 years ago, it was not designed for data transfer via the web. In response to the demands of the NVO, we have designed and implemented an application layer that will allow our system to communicate with others. Sponsored by the NRAO and California State University, San Marcos.

Solar-Heliospheric-Interstellar Cosmic Ray Tour with the NASA Virtual Energetic Particle Observatory and the Space Physics Data Facility

NASA Astrophysics Data System (ADS)

Cooper, John F.; Papitashvili, Natalia E.; Johnson, Rita C.; Lal, Nand; McGuire, Robert E.

2015-04-01

NASA now has a large collection of solar, heliospheric, and local interstellar (Voyager 1) cosmic ray particle data sets that can be accessed through the data system services of the NASA Virtual Energetic Particle Observatory (VEPO) in collaboration with the NASA Space Physics Data Facility SPDF), respectively led by the first and last authors. The VEPO services were developed to enhance the long-existing OMNIWeb solar wind and energetic particle services of SPDF for on-line browse, correlative, and statistical analysis of NASA and ESA mission fields, plasma, and energetic particle data. In this presentation we take of tour through VEPO and SPDF of SEP reservoir events, the outer heliosphere earlier surveyed by the Pioneer, Voyager, and Ulysses spacecraft and now being probed by New Horizons, and the heliosheath-heliopause-interstellar regions now being explored by the Voyagers and IBEX. Implications of the latter measurements are also considered for the flux spectra of low to high energy cosmic rays in interstellar space.

LAMOST CCD camera-control system based on RTS2

NASA Astrophysics Data System (ADS)

Tian, Yuan; Wang, Zheng; Li, Jian; Cao, Zi-Huang; Dai, Wei; Wei, Shou-Lin; Zhao, Yong-Heng

2018-05-01

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is the largest existing spectroscopic survey telescope, having 32 scientific charge-coupled-device (CCD) cameras for acquiring spectra. Stability and automation of the camera-control software are essential, but cannot be provided by the existing system. The Remote Telescope System 2nd Version (RTS2) is an open-source and automatic observatory-control system. However, all previous RTS2 applications were developed for small telescopes. This paper focuses on implementation of an RTS2-based camera-control system for the 32 CCDs of LAMOST. A virtual camera module inherited from the RTS2 camera module is built as a device component working on the RTS2 framework. To improve the controllability and robustness, a virtualized layer is designed using the master-slave software paradigm, and the virtual camera module is mapped to the 32 real cameras of LAMOST. The new system is deployed in the actual environment and experimentally tested. Finally, multiple observations are conducted using this new RTS2-framework-based control system. The new camera-control system is found to satisfy the requirements for automatic camera control in LAMOST. This is the first time that RTS2 has been applied to a large telescope, and provides a referential solution for full RTS2 introduction to the LAMOST observatory control system.

Llnking the EarthScope Data Virtual Catalog to the GEON Portal

NASA Astrophysics Data System (ADS)

Lin, K.; Memon, A.; Baru, C.

2008-12-01

The EarthScope Data Portal provides a unified, single-point of access to EarthScope data and products from USArray, Plate Boundary Observatory (PBO), and San Andreas Fault Observatory at Depth (SAFOD) experiments. The portal features basic search and data access capabilities to allow users to discover and access EarthScope data using spatial, temporal, and other metadata-based (data type, station specific) search conditions. The portal search module is the user interface implementation of the EarthScope Data Search Web Service. This Web Service acts as a virtual catalog that in turn invokes Web services developed by IRIS (Incorporated Research Institutions for Seismology), UNAVCO (University NAVSTAR Consortium), and GFZ (German Research Center for Geosciences) to search for EarthScope data in the archives at each of these locations. These Web Services provide information about all resources (data) that match the specified search conditions. In this presentation we will describe how the EarthScope Data Search Web service can be integrated into the GEONsearch application in the GEON Portal (see http://portal.geongrid.org). Thus, a search request issued at the GEON Portal will also search the EarthScope virtual catalog thereby providing users seamless access to data in GEON as well as the Earthscope via a common user interface.

A virtual radiation belt observatory: Looking forward to the electronic geophysical year

NASA Astrophysics Data System (ADS)

Baker, D. N.; Green, J. C.; Kroehl, H. W.; Kihn, E.; Virbo Team

During the International Geophysical Year (1957-1958), member countries established many new capabilities pursuing the major IGY objectives of collecting geophysical data as widely as possible and providing free access to these data for all scientists around the globe. A key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories. The worldwide scientific community has now endorsed and is promoting an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the 50th anniversary of the IGY in 2007-2008 and would provide a forward impetus to geophysics in the 21st century, similar to that provide by the IGY fifty years ago. The eGY concept advocates the establishment of a series of virtual geophysical observatories now being deployed in cyberspace. We are developing the concept of a Virtual Radiation Belt Observatory (ViRBO) that will bring together near-earth particle and field measurements acquired by NASA, NOAA, DoD, DOE, and other spacecraft. We discuss plans to aggregate these measurements into a readily accessible database along with analysis, visualization, and display tools that will make radiation belt information available and useful both to the scientific community and to the user community. We envision that data from the various agencies along with models being developed under the auspices of the National Science Foundation Center for Integrated Space Weather Modeling (CISM) will help us to provide an excellent `climatology' of the radiation belts over the past several decades. In particular, we would plan to use these data to drive physical models of the radiation belts to form a gridded database which would characterize particle and field properties on solar-cycle (11-year) time scales. ViRBO will also provide up-to-date specification of conditions for event analysis and anomaly resolution. We are even examining the possibilities for near-realtime acquisition of data and utilization of CISM-developed forecast tools in order to provide users with advanced space weather capabilities.

AMON: Transition to real-time operations

NASA Astrophysics Data System (ADS)

Cowen, D. F.; Keivani, A.; Tešić, G.

2016-04-01

The Astrophysical Multimessenger Observatory Network (AMON) will link the world's leading high-energy neutrino, cosmic-ray, gamma-ray and gravitational wave observatories by performing real-time coincidence searches for multimessenger sources from observatories' subthreshold data streams. The resulting coincidences will be distributed to interested parties in the form of electronic alerts for real-time follow-up observation. We will present the science case, design elements, current and projected partner observatories, status of the AMON project, and an initial AMON-enabled analysis. The prototype of the AMON server has been online since August 2014 and processing archival data. Currently, we are deploying new high-uptime servers and will be ready to start issuing alerts as early as winter 2015/16.

Astro-1 Image Taken by Ultraviolet Imaging Telescope

NASA Technical Reports Server (NTRS)

1990-01-01

This image shows a part of the Cygnus loop supernova remnant, taken by the Ultraviolet Imaging Telescope (UIT) on the Astro Observatory during the Astro-1 mission (STS-35) on December 5, 1990. Pictured is a portion of the huge Cygnus loop, an array of interstellar gas clouds that have been blasted by a 900,000 mile per hour shock wave from a prehistoric stellar explosion, which occurred about 20,000 years ago, known as supernova. With ultraviolet and x-rays, astronomers can see emissions from extremely hot gases, intense magnetic fields, and other high-energy phenomena that more faintly appear in visible and infrared light or in radio waves that are crucial to deepening the understanding of the universe. The Astro Observatory was designed to explore the universe by observing and measuring the ultraviolet radiation from celestial objects. Three instruments make up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had managment responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

Deformation and deceleration of coronal wave

NASA Astrophysics Data System (ADS)

Xue, Z. K.; Qu, Z. Q.; Yan, X. L.; Zhao, L.; Ma, L.

2013-08-01

Aims: We studied the kinematics and morphology of two coronal waves to better understand the nature and origin of coronal waves. Methods: Using multi-wavelength observations of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) and the Extreme Ultraviolet Imager (EUVI) on board the twin spacecraft Solar-TErrestrial RElations Observatory (STEREO), we present morphological and dynamic characteristics of consecutive coronal waves on 2011 March 24. We also show the coronal magnetic field based on the potential field source surface model. Results: This event contains several interesting aspects. The first coronal wave initially appeared after a surge-like eruption. Its front was changed and deformed significantly from a convex shape to a line-shaped appearance, and then to a concave configuration during its propagation to the northwest. The initial speeds ranged from 947 km s-1 to 560 km s-1. The first wave decelerated significantly after it passed through a filament channel. After the deceleration, the final propagation speeds of the wave were from 430 km s-1 to 312 km s-1. The second wave was found to appear after the first wave in the northwest side of the filament channel. Its wave front was more diffused and the speed was around 250 km s-1, much slower than that of the first wave. Conclusions: The deformation of the first coronal wave was caused by the different speeds along different paths. The sudden deceleration implies that the refraction of the first wave took place at the boundary of the filament channel. The event provides evidence that the first coronal wave may be a coronal MHD shock wave, and the second wave may be the apparent propagation of the brightenings caused by successive stretching of the magnetic field lines.

Overview of SOFIA's General Capabilities and Project Status

NASA Astrophysics Data System (ADS)

Tielens, A.

2005-12-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5-meter telescope installed in a Boeing 747-SP to be flown at altitudes higher than ˜12 km. This allows observations in the stratosphere above virtually all of the atmosphere's water vapor. SOFIA's first generation scientific instruments span wavelengths from 0.3 to 700 microns. Upcoming engineering test flights will be followed by scientific test flights commissioning the observatory and instruments. In regular operations there are planned more than 120 research flights per year with as much as 8 to 10 hours of observing time per flight.

Teaching undergraduate astrophysics with PIRATE

NASA Astrophysics Data System (ADS)

Brodeur, M. S.; Kolb, U.; Minocha, S.; Braithwaite, N.

2014-12-01

PIRATE is a 0.43m semi-autonomous research and teaching observatory owned by The Open University, UK. Since 2010, it has been reserved for several months of each year for teaching astronomy in the OU's undergraduate programme. As students in these courses operate PIRATE remotely rather than travelling to the observatory itself, we chose to investigate whether effective learning was adversely affected by the absence of a more traditional `hands on' experience. We discuss student perspectives on the technologies employed (i.e., remote and virtual investigations), the impact these had on perceived course outcomes, and consider implications for future teaching and outreach.

Ultrafast Synthetic Transmit Aperture Imaging Using Hadamard-Encoded Virtual Sources With Overlapping Sub-Apertures.

PubMed

Ping Gong; Pengfei Song; Shigao Chen

2017-06-01

The development of ultrafast ultrasound imaging offers great opportunities to improve imaging technologies, such as shear wave elastography and ultrafast Doppler imaging. In ultrafast imaging, there are tradeoffs among image signal-to-noise ratio (SNR), resolution, and post-compounded frame rate. Various approaches have been proposed to solve this tradeoff, such as multiplane wave imaging or the attempts of implementing synthetic transmit aperture imaging. In this paper, we propose an ultrafast synthetic transmit aperture (USTA) imaging technique using Hadamard-encoded virtual sources with overlapping sub-apertures to enhance both image SNR and resolution without sacrificing frame rate. This method includes three steps: 1) create virtual sources using sub-apertures; 2) encode virtual sources using Hadamard matrix; and 3) add short time intervals (a few microseconds) between transmissions of different virtual sources to allow overlapping sub-apertures. The USTA was tested experimentally with a point target, a B-mode phantom, and in vivo human kidney micro-vessel imaging. Compared with standard coherent diverging wave compounding with the same frame rate, improvements on image SNR, lateral resolution (+33%, with B-mode phantom imaging), and contrast ratio (+3.8 dB, with in vivo human kidney micro-vessel imaging) have been achieved. The f-number of virtual sources, the number of virtual sources used, and the number of elements used in each sub-aperture can be flexibly adjusted to enhance resolution and SNR. This allows very flexible optimization of USTA for different applications.

VO-ESD: a virtual observatory approach to describe the geomagnetic field temporal variations with application to Swarm data

NASA Astrophysics Data System (ADS)

Saturnino, Diana; Langlais, Benoit; Amit, Hagay; Mandea, Mioara; Civet, François; Beucler, Éric

2017-04-01

A complete description of the main geomagnetic field temporal variation is crucial to understand dynamics in the core. This variation, termed secular variation (SV), is known with high accuracy at ground magnetic observatory locations. However the description of its spatial variability is hampered by the globally uneven distribution of the observatories. For the past two decades a global coverage of the field changes has been allowed by satellites. Their surveys of the geomagnetic field have been used to derive and improve global spherical harmonic (SH) models through some strict data selection schemes to minimise external field contributions. But discrepancies remain between ground measurements and field predictions by these models. Indeed, the global models do not reproduce small spatial scales of the field temporal variations. To overcome this problem we propose a modified Virtual Observatory (VO) approach by defining a globally homogeneous mesh of VOs at satellite altitude. With this approach we directly extract time series of the field and its temporal variation from satellite measurements as it is done at observatory locations. As satellite measurements are acquired at different altitudes a correction for the altitude is needed. Therefore, we apply an Equivalent Source Dipole (ESD) technique for each VO and each given time interval to reduce all measurements to a unique location, leading to time series similar to those available at ground magnetic observatories. Synthetic data is first used to validate the new VO-ESD approach. Then, we apply our scheme to measurements from the Swarm mission. For the first time, a 2.5 degrees resolution global mesh of VO times series is built. The VO-ESD derived time series are locally compared to ground observations as well as to satellite-based model predictions. The approach is able to describe detailed temporal variations of the field at local scales. The VO-ESD time series are also used to derive global SH models. Without regularization these models describe well the secular trend of the magnetic field. The derivation of longer VO-ESD time series, as more data will be made available, will allow the study of field temporal variations features such as geomagnetic jerks.

Image Processing for Educators in Global Hands-On Universe

NASA Astrophysics Data System (ADS)

Miller, J. P.; Pennypacker, C. R.; White, G. L.

2006-08-01

A method of image processing to find time-varying objects is being developed for the National Virtual Observatory as part of Global Hands-On Universe(tm) (Lawrence Hall of Science; University of California, Berkeley). Objects that vary in space or time are of prime importance in modern astronomy and astrophysics. Such objects include active galactic nuclei, variable stars, supernovae, or moving objects across a field of view such as an asteroid, comet, or extrasolar planet transiting its parent star. The search for these objects is undertaken by acquiring an image of the region of the sky where they occur followed by a second image taken at a later time. Ideally, both images are taken with the same telescope using the same filter and charge-coupled device. The two images are aligned and subtracted with the subtracted image revealing any changes in light during the time period between the two images. We have used a method of Christophe Alard using the image processing software IDL Version 6.2 (Research Systems, Inc.) with the exception of the background correction, which is done on the two images prior to the subtraction. Testing has been extensive, using images provided by a number of National Virtual Observatory and collaborating projects. They include the Supernovae Trace Cosmic Expansion (Cerro Tololo Inter-American Observatory), Supernovae/ Acceleration Program (Lawrence Berkeley National Laboratory), Lowell Observatory Near-Earth Object Search (Lowell Observatory), and the Centre National de la Recherche Scientifique (Paris, France). Further testing has been done with students, including a May 2006 two week program at the Lawrence Berkeley National Laboratory. Students from Hardin-Simmons University (Abilene, TX) and Jackson State University (Jackson, MS) used the subtraction method to analyze images from the Cerro Tololo Inter-American Observatory (CTIO) searching for new asteroids and Kuiper Belt objects. In October 2006 students from five U.S. high schools will use the subtraction method in an asteroid search campaign using CTIO images with 7-day follow-up images to be provided by the Las Cumbres Observatory (Santa Barbara, CA). During the Spring 2006 semester, students from Cape Fear High School used the method to search for near-Earth objects and supernovae. Using images from the Astronomical Research Institute (Charleston, IL) the method contributed to the original discovery of two supernovae, SN 2006al and SN 2006bi.

Space Based Gravitational Wave Observatories (SGOs)

NASA Technical Reports Server (NTRS)

Livas, Jeff

2014-01-01

Space-based Gravitational-wave Observatories (SGOs) will enable the systematic study of the frequency band from 0.0001 - 1 Hz of gravitational waves, where a rich array of astrophysical sources is expected. ESA has selected The Gravitational Universe as the science theme for the L3 mission opportunity with a nominal launch date in 2034. This will be at a minimum 15 years after ground-based detectors and pulsar timing arrays announce their first detections and at least 18 years after the LISA Pathfinder Mission will have demonstrated key technologies in a dedicated space mission. It is therefore important to develop mission concepts that can take advantage of the momentum in the field and the investment in both technology development and a precision measurement community on a more near-term timescale than the L3 opportunity. This talk will discuss a mission concept based on the LISA baseline that resulted from a recent mission architecture study.

Charge management for gravitational-wave observatories using UV LEDs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pollack, S. E.; Turner, M. D.; Schlamminger, S.

Accumulation of electrical charge on the end mirrors of gravitational-wave observatories can become a source of noise limiting the sensitivity of such detectors through electronic couplings to nearby surfaces. Torsion balances provide an ideal means for testing gravitational-wave technologies due to their high sensitivity to small forces. Our torsion pendulum apparatus consists of a movable plate brought near a plate pendulum suspended from a nonconducting quartz fiber. A UV LED located near the pendulum photoejects electrons from the surface, and a UV LED driven electron gun directs photoelectrons towards the pendulum surface. We have demonstrated both charging and discharging ofmore » the pendulum with equivalent charging rates of {approx}10{sup 5}e/s, as well as spectral measurements of the pendulum charge resulting in a white noise level equivalent to 3x10{sup 5}e/{radical}(Hz).« less

Laplacean Ideology for Preliminary Orbit Determination and Moving Celestial Body Identification in Virtual Epoch

NASA Astrophysics Data System (ADS)

Bykov, O. P.

Any CCD frames with stars or galaxies or clusters and other images must be studied for a searching of moving celestial objects, namely asteroids, comets, artificial Earth satellites inside them. At Pulkovo Astronomical Observatory, new methods and software were elaborated to solve this problem.

FixO3 project results, legacy and module migration to EMSO

NASA Astrophysics Data System (ADS)

Lampitt, Richard

2017-04-01

The fixed point open ocean observatory network (FixO3) project is an international project aimed at integrating in a single network all fixed point open ocean observatories operated by European organisations and to harmonise and coordinate technological, procedural and data management across the stations. The project is running for four years since September 2013 with 29 partners across Europe and a budget of 7M Euros and is now coming to its final phase. In contrast to several past programmes, the opportunity has arisen to ensure that many of the project achievements can migrate into the newly formed European Multidisciplinary Seafloor and water column Observatory (EMSO) research infrastructure. The final phase of the project will focus on developing a strategy to transfer the results in an efficient way to maintain their relevance and maximise their use. In this presentation, we will highlight the significant achievements of FixO3 over the past three years focussing on the modules which will be transferred to EMSO in the coming 9 months. These include: 1. Handbook of best practices for operating fixed point observatories 2. Metadata catalogue 3. Earth Virtual Observatory (EarthVO) for data visualisation and comparison 4. Open Ocean Observatory Yellow Pages (O3YP) 5. Training material for hardware, data and data products used

Simultaneous Observations of a Large-scale Wave Event in the Solar Atmosphere: From Photosphere to Corona

NASA Astrophysics Data System (ADS)

Shen, Yuandeng; Liu, Yu

2012-06-01

For the first time, we report a large-scale wave that was observed simultaneously in the photosphere, chromosphere, transition region, and low corona layers of the solar atmosphere. Using the high temporal and high spatial resolution observations taken by the Solar Magnetic Activity Research Telescope at Hida Observatory and the Atmospheric Imaging Assembly (AIA) on board Solar Dynamic Observatory, we find that the wave evolved synchronously at different heights of the solar atmosphere, and it propagated at a speed of 605 km s-1 and showed a significant deceleration (-424 m s-2) in the extreme-ultraviolet (EUV) observations. During the initial stage, the wave speed in the EUV observations was 1000 km s-1, similar to those measured from the AIA 1700 Å (967 km s-1) and 1600 Å (893 km s-1) observations. The wave was reflected by a remote region with open fields, and a slower wave-like feature at a speed of 220 km s-1 was also identified following the primary fast wave. In addition, a type-II radio burst was observed to be associated with the wave. We conclude that this wave should be a fast magnetosonic shock wave, which was first driven by the associated coronal mass ejection and then propagated freely in the corona. As the shock wave propagated, its legs swept the solar surface and thereby resulted in the wave signatures observed in the lower layers of the solar atmosphere. The slower wave-like structure following the primary wave was probably caused by the reconfiguration of the low coronal magnetic fields, as predicted in the field-line stretching model.

Estimation of accuracy of time synchronization obtained by means of clock transportation

NASA Astrophysics Data System (ADS)

Zhang, Yuzhen; Ma, Dekang; Jin, Wenjing; Zhao, Gang; Huang, Peicheng

A portable clock experiment was carried out in October 1985 between Shanghai Observatory and Beijing Observatory using a small quartz clock made in Switzerland. The accuracy of time synchronization in 5 days is 70.18 microsec and the accuracy of determining the transmission time of short wave is satisfactory for reduction of the astronomical observations to the same master clock.

A Process Study of the Development of Virtual Research Environments

NASA Astrophysics Data System (ADS)

Ahmed, I.; Cooper, K.; McGrath, R.; Griego, G.; Poole, M. S.; Hanisch, R. J.

2014-05-01

In recent years, cyberinfrastructures have been deployed to create virtual research environments (VREs) - such as the Virtual Astronomical Observatory (VAO) - to enhance the quality and speed of scientific research, and to foster global scientific communities. Our study utilizes process methodology to study the evolution of VREs. This approach focuses on a series of events that bring about or lead to some outcome, and attempts to specify the generative mechanism that could produce the event series. This paper briefly outlines our approach and describes initial results of a case study of the VAO, one of the participating VREs. The case study is based on interviews with seven individuals participating in the VAO, and analysis of project documents and online resources. These sources are hand tagged to identify events related to the thematic tracks, to yield a narrative of the project. Results demonstrate the event series of an organization through traditional methods augmented by virtual sources.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yukhimuk, V.; Roussel-Dupre, R.

In this paper the evolution of nonlinear scattering of whistler mode waves by kinetic Alfven waves (KAW) in time and two spatial dimensions is studied analytically. The authors suggest this nonlinear process as a mechanism of kinetic Alfven wave generation in space plasmas. This mechanism can explain the dependence of Alfven wave generation on whistler waves observed in magnetospheric and ionospheric plasmas. The observational data show a dependence for the generation of long periodic pulsations Pc5 on whistler wave excitation in the auroral and subauroral zone of the magnetosphere. This dependence was first observed by Ondoh T.I. For 79 casesmore » of VLF wave excitation registered by Ondoh at College Observatory (L=64.6 N), 52 of them were followed by Pc5 geomagnetic pulsation generation. Similar results were obtained at the Loparskaia Observatory (L=64 N) for auroral and subauroral zone of the magnetosphere. Thus, in 95% of the cases when VLF wave excitation occurred the generation of long periodic geomagnetic pulsations Pc5 were observed. The observations also show that geomagnetic pulsations Pc5 are excited simultaneously or insignificantly later than VLF waves. In fact these two phenomena are associated genetically: the excitation of VLF waves leads to the generation of geomagnetic pulsations Pc5. The observations show intensive generation of geomagnetic pulsations during thunderstorms. Using an electromagnetic noise monitoring system covering the ULF range (0.01-10 Hz) A.S. Fraser-Smith observed intensive ULF electromagnetic wave during a large thunderstorm near the San-Francisco Bay area on September 23, 1990. According to this data the most significant amplification in ULF wave activity was observed for waves with a frequency of 0.01 Hz and it is entirely possible that stronger enhancements would have been measured at lower frequencies.« less

An extreme ultraviolet wave associated with a failed eruption observed by the Solar Dynamics Observatory

NASA Astrophysics Data System (ADS)

Zheng, R.; Jiang, Y.; Yang, J.; Bi, Y.; Hong, J.; Yang, B.; Yang, D.

2012-05-01

Aims: Taking advantage of the high temporal and spatial resolution of the Solar Dynamics Observatory (SDO) observations, we present an extreme ultraviolet (EUV) wave associated with a failed filament eruption that generated no coronal mass ejection (CME) on 2011 March 1. We aim at understanding the nature and origin of this EUV wave. Methods: Combining the high-quality observations in the photosphere, the chromosphere, and the corona, we studied the characteristics of the wave and its relations to the associated eruption. Results: The event occurred at an ephemeral region near a small active region. The continuous magnetic flux cancelation in the ephemeral region produced pre-eruption brightenings and two EUV jets, and excited the filament eruption, accompanying it with a microflare. After the eruption, the filament material appeared far from the eruption center, and the ambient loops seemed to be intact. It was evident that the filament eruption had failed and was not associated with a CME. The wave happened just after the north jet arrived, and apparently emanated ahead of the north jet, far from the eruption center. The wave propagated at nearly constant velocities in the range of 260-350 km s-1, with a slight negative acceleration in the last phase. Remarkably, the wave continued to propagate, and a loop in its passage was intact when wave and loop met. Conclusions: Our analysis confirms that the EUV wave is a true wave, which we interpret as a fast-mode wave. In addition, the close temporal and spatial relationship between the wave and the jet provides evidence that the wave was likely triggered by the jet when the CME failed to happen. Three movies are available in electronic form at http://www.aanda.org

ELF/VLF Wave Generation and Scattering from Modulated Heating of the Ionosphere at Arecibo Observatory

NASA Astrophysics Data System (ADS)

Maxworth, A. S.; Golkowski, M.; McCormick, J.; Cohen, M.; Hosseini, P.; Bittle, J.

2017-12-01

The recently completed ionospheric heater at Arecibo Observatory is used for modulated HF (5 or 8 MHz) heating of the ionosphere, to generate ELF/VLF (3 Hz - 30 kHz) waves. Observation of ramp and tone signals at frequencies from hundreds of Hz to several kHz at multiple receivers confirms the ability of the heater to modulate D region currents and create an ELF/VLF antenna in the ionosphere. Observed ELF/VLF signal amplitudes are lower than for similar experiments performed at high latitudes at the HAARP and Tromso facilities, for a variety of reasons including the reduced natural currents at mid latitudes, and the lower HF power of the Arecibo heater. The heating of the overhead ionosphere is also observed to change the Earth-ionosphere waveguide propagation characteristics as is evident from simultaneous observations of lightning induced sferics and VLF transmitter signals that propagate under the heated region. The active heating of the ionosphere modifies the reflection of incident VLF (3-30 kHz) waves. We present initial observations of HF heating of the D-region and resulting ELF/VLF wave generation.

Improved surface-wave retrieval from ambient seismic noise by multi-dimensional deconvolution

NASA Astrophysics Data System (ADS)

Wapenaar, Kees; Ruigrok, Elmer; van der Neut, Joost; Draganov, Deyan

2011-01-01

The methodology of surface-wave retrieval from ambient seismic noise by crosscorrelation relies on the assumption that the noise field is equipartitioned. Deviations from equipartitioning degrade the accuracy of the retrieved surface-wave Green's function. A point-spread function, derived from the same ambient noise field, quantifies the smearing in space and time of the virtual source of the Green's function. By multidimensionally deconvolving the retrieved Green's function by the point-spread function, the virtual source becomes better focussed in space and time and hence the accuracy of the retrieved surface-wave Green's function may improve significantly. We illustrate this at the hand of a numerical example and discuss the advantages and limitations of this new methodology.

Saint Petersburg magnetic observatory: from Voeikovo subdivision to INTERMAGNET certification

NASA Astrophysics Data System (ADS)

Sidorov, Roman; Soloviev, Anatoly; Krasnoperov, Roman; Kudin, Dmitry; Grudnev, Andrei; Kopytenko, Yury; Kotikov, Andrei; Sergushin, Pavel

2017-11-01

Since June 2012 the Saint Petersburg magnetic observatory is being developed and maintained by two institutions of the Russian Academy of Sciences (RAS) - the Geophysical Center of RAS (GC RAS) and the Saint Petersburg branch of the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of RAS (IZMIRAN SPb). On 29 April 2016 the application of the Saint Petersburg observatory (IAGA code SPG) for introduction into the INTERMAGNET network was accepted after approval by the experts of the first definitive dataset over 2015, produced by the GC RAS, and on 9 June 2016 the SPG observatory was officially certified. One of the oldest series of magnetic observations, originating in 1834, was resumed in the 21st century, meeting the highest quality standards and all modern technical requirements. In this paper a brief historical and scientific background of the SPG observatory foundation and development is given, the stages of its renovation and upgrade in the 21st century are described, and information on its current state is provided. The first results of the observatory functioning are discussed and geomagnetic variations registered at the SPG observatory are assessed and compared with geomagnetic data from the INTERMAGNET observatories located in the same region.

Toward a Space based Gravitational Wave Observatory

NASA Technical Reports Server (NTRS)

Stebbins, Robin T.

2015-01-01

A space-based GW observatory will produce spectacular science. The LISA mission concept: (a) Long history, (b) Very well-studied, including de-scopes, (c) NASAs Astrophysics Strategic Plan calls for a minority role in ESAs L3 mission opportunity. To that end, NASA is Participating in LPF and ST7 Developing appropriate technology for a LISA-like mission Preparing to seek an endorsement for L3 participation from the 2020 decadal review.

Accessing SDO data in a pipeline environment using the VSO WSDL/SOAP interface

NASA Astrophysics Data System (ADS)

Suarez Sola, F. I.; Hourcle, J. A.; Amezcua, A.; Bogart, R.; Davey, A. R.; Gurman, J. B.; Hill, F.; Hughitt, V. K.; Martens, P. C.; Spencer, J.; Vso Team

2010-12-01

As part of the Virtual Solar Observatory (VSO) effort to support the Solar Dynamics Observatory (SDO) data, the VSO has worked on bringing up to date its WSDL document and SOAP interface to make it compatible with most widely used web services core engines. (E.g. axis2, jws, etc.) In this presentation we will explore the possibilities available for searching and/or fetching data within pipeline code. We will explain some of the WSDL/VSO-SDO interface intricacies and show how the vast amount of data that is available via the VSO can be tapped via IDL, Java, Perl or C in an uncomplicated way.

Design and Implement of Astronomical Cloud Computing Environment In China-VO

NASA Astrophysics Data System (ADS)

Li, Changhua; Cui, Chenzhou; Mi, Linying; He, Boliang; Fan, Dongwei; Li, Shanshan; Yang, Sisi; Xu, Yunfei; Han, Jun; Chen, Junyi; Zhang, Hailong; Yu, Ce; Xiao, Jian; Wang, Chuanjun; Cao, Zihuang; Fan, Yufeng; Liu, Liang; Chen, Xiao; Song, Wenming; Du, Kangyu

2017-06-01

Astronomy cloud computing environment is a cyber-Infrastructure for Astronomy Research initiated by Chinese Virtual Observatory (China-VO) under funding support from NDRC (National Development and Reform commission) and CAS (Chinese Academy of Sciences). Based on virtualization technology, astronomy cloud computing environment was designed and implemented by China-VO team. It consists of five distributed nodes across the mainland of China. Astronomer can get compuitng and storage resource in this cloud computing environment. Through this environments, astronomer can easily search and analyze astronomical data collected by different telescopes and data centers , and avoid the large scale dataset transportation.

Showing Complex Astrophysical Settings Through Virtual Reality

NASA Astrophysics Data System (ADS)

Green, Joel; Smith, Denise; Smith, Louis Chad; Lawton, Brandon; Lockwood, Alexandra; Jirdeh, Hussein

2018-01-01

The James Webb Space Telescope (JWST), NASA’s next great observatory launching in spring 2019, will routinely showcase astrophysical concepts that will challenge the public's understanding. Emerging technologies such as virtual reality bring the viewer into the data and the concept in previously unimaginable immersive detail. For example, we imagine a spacefarer inside a protoplanetary disk, seeing the accretion process directly. STScI is pioneering some tools related to JWST for showcasing at AAS, and in local events, which I highlight here. If we develop materials properly tailored to this medium, we can reach more diverse audiences than ever before.

The GTC scientific archive

NASA Astrophysics Data System (ADS)

Gutiérrez, R.; Solano, E.

2011-11-01

At present, data management in telescopes ofclass 8-10 meters is very inefficient. The Gran Telescopio Canarias(GTC) scientific archive that is being developed by the Centro deAstrobiología (CAB) in the framework of the Spanish Virtual Observatoryis aimed at avoiding this situation, providing the telescope with anarchive accessible via internet, guaranteeing the accessibility,efficiency, visibility and data security demanded by a telescope of itsentity. The GTC archive will also be adapted to the standards defined bythe International Virtual Observatory, maximizing the visibility of thedata produced by the telescope. The main characteristics of the GTCscientific archive are described in this poster.

Detection and Characterization of Micrometeoroid Impacts on LISA Pathfinder

NASA Astrophysics Data System (ADS)

Hourihane, S.; Littenberg, T.; Baker, J. G.; Pagane, N.; Slutsky, J. P.; Thorpe, J. I.

2017-12-01

LISA Pathfinder (LPF) was a joint ESA/NASA technology demonstration mission for the Laser Interferometer Space Antenna (LISA) gravitational wave observatory. LPF, the most sensitive accelerometer ever flown in space, was launched in December 2015 and successfully concluded its mission in July 2017. Due in part to LPFs success, LISA was selected by the European Space Agency for launch in the early 2030s. An ancillary benefit of LPFs capabilities made it a sensitive detector of micrometeoroid impacts. We report on the capabilities of LPF to detect and characterize impacts, and progress towards using those inferences to advance our understanding of the micrometeoroid environment in the solar system. In doing so, we assess the prospect of space-based gravitational wave observatories as micrometeoroid detection instruments.

Characterizing seismic noise in the 2-20 Hz band at a gravitational wave observatory

NASA Astrophysics Data System (ADS)

Coward, D.; Turner, J.; Blair, D.; Galybin, K.

2005-04-01

We present a study of seismic noise, using an array of seismic sensors, at the Australian International Gravitational Observatory. We show that despite excellent attenuation of 2-20 Hz seismic waves from the soil properties of the site, which is confirmed by a specific experiment, there are important technical issues associated with local sources of vibration originating from within the laboratory buildings. In particular, we identify vibrations from air-filtration equipment propagating throughout the site. We find significant building resonances in the 2-13 Hz band and identify seismic noise originating from regional mine blasts hundreds of kilometers distant. All these noise sources increase the performance requirements on vibration isolation in the 2-20 Hz frequency band.

VirGO: A Visual Browser for the ESO Science Archive Facility

NASA Astrophysics Data System (ADS)

Chéreau, Fabien

2012-04-01

VirGO is the next generation Visual Browser for the ESO Science Archive Facility developed by the Virtual Observatory (VO) Systems Department. It is a plug-in for the popular open source software Stellarium adding capabilities for browsing professional astronomical data. VirGO gives astronomers the possibility to easily discover and select data from millions of observations in a new visual and intuitive way. Its main feature is to perform real-time access and graphical display of a large number of observations by showing instrumental footprints and image previews, and to allow their selection and filtering for subsequent download from the ESO SAF web interface. It also allows the loading of external FITS files or VOTables, the superimposition of Digitized Sky Survey (DSS) background images, and the visualization of the sky in a `real life' mode as seen from the main ESO sites. All data interfaces are based on Virtual Observatory standards which allow access to images and spectra from external data centers, and interaction with the ESO SAF web interface or any other VO applications supporting the PLASTIC messaging system.

Social Media, Education and Data Sharing

NASA Astrophysics Data System (ADS)

King, T. A.; Walker, R. J.; Masters, A.

2011-12-01

Social media is a blending of technology and social interactions which allows for the creation and exchange of user-generated content. Social media started as conversations between groups of people, now companies are using social media to communicate with customers and politicians use it to communicate with their constituents. Social media is now finding uses in the science communities. This adoption is driven by the expectation of students that technology will be an integral part of their research and that it will match the technology they use in their social lifes. Students are using social media to keep informed and collaborate with others. They have also replaced notepads with smart mobile devices. We have been introducing social media components into Virtual Observatories as a way to quickly access and exchange information with a tap or a click. We discuss the use of Quick Response (QR) codes, Digital Object Identifiers (DOIs), unique identifiers, Twitter, Facebook and tiny URL redirects as ways to enable easier sharing of data and information. We also discuss what services and features are needed in a Virtual Observatory to make data sharing with social media possible.

A Simple and Customizable Web Interface to the Virtual Solar Observatory

NASA Astrophysics Data System (ADS)

Hughitt, V. Keith; Hourcle, J.; Suarez-Sola, I.; Davey, A.

2010-05-01

As the variety and number of solar data sources continue to increase at a rapid rate, the importance of providing methods to search through these sources becomes increasingly important. By taking advantage of the power of modern JavaScript libraries, a new version of the Virtual Solar Observatory's web interface aims to provide a significantly faster and simpler way to explore the multitude of data repositories available. Querying asynchroniously serves not only to eliminates bottlenecks resulting from slow or unresponsive data providers, but also allows for displaying of results as soon as they are returned. Implicit pagination and post-query filtering enables users to work with large result-sets, while a more modular and customizable UI provides a mechanism for customizing both the look-and-feel and behavior of the VSO web interface. Finally, the new web interface features a custom widget system capable of displaying additional tools and information along-side of the standard VSO search form. Interested users can also write their own widgets and submit them for future incorporation into VSO.

VO-KOREL: A Fourier Disentangling Service of the Virtual Observatory

NASA Astrophysics Data System (ADS)

Škoda, Petr; Hadrava, Petr; Fuchs, Jan

2012-04-01

VO-KOREL is a web service exploiting the technology of the Virtual Observatory for providing astronomers with the intuitive graphical front-end and distributed computing back-end running the most recent version of the Fourier disentangling code KOREL. The system integrates the ideas of the e-shop basket, conserving the privacy of every user by transfer encryption and access authentication, with features of laboratory notebook, allowing the easy housekeeping of both input parameters and final results, as well as it explores a newly emerging technology of cloud computing. While the web-based front-end allows the user to submit data and parameter files, edit parameters, manage a job list, resubmit or cancel running jobs and mainly watching the text and graphical results of a disentangling process, the main part of the back-end is a simple job queue submission system executing in parallel multiple instances of the FORTRAN code KOREL. This may be easily extended for GRID-based deployment on massively parallel computing clusters. The short introduction into underlying technologies is given, briefly mentioning advantages as well as bottlenecks of the design used.

Improving Existing EPO Efforts with Data Access through the National Virtual Observatory

NASA Astrophysics Data System (ADS)

Raddick, M. J.; Christian, C. A.; O'Mullane, W. J.

2005-05-01

The National Virtual Observatory (NVO) is developing tools to enable astronomy data to be shared seamlessly across the Internet. The goal of the NVO is to allow anyone on the Internet to access all astronomy data ever measured, with any instrument, in any wavelength. The NVO's research efforts focus on allowing scientists to access existing online data, adding value to each dataset by virtue of its connection to others. Similarly, the NVO's Education and Public Outreach (EPO) efforts focus on connecting existing projects with the our seamless access to real, modern astronomy data from thousands of research projects. We hope that this connection will provide countless opportunities to expand and enhance existing EPO projects. Some of the projects currently working with NVO are the CLEA labs at Gettysburg College, Project LITE at Boston University, and Adler Planetarium. In this poster, I will describe the current EPO efforts that incorporate the NVO's data access tools. I will also provide a tutorial for EPO developers, with practical suggestions on how to incorporate NVO tools into existing projects. I will also give contact information for further help.

Building a VO-compliant Radio Astronomical DAta Model for Single-dish radio telescopes (RADAMS)

NASA Astrophysics Data System (ADS)

Santander-Vela, Juan de Dios; García, Emilio; Leon, Stephane; Espigares, Victor; Ruiz, José Enrique; Verdes-Montenegro, Lourdes; Solano, Enrique

2012-11-01

The Virtual Observatory (VO) is becoming the de-facto standard for astronomical data publication. However, the number of radio astronomical archives is still low in general, and even lower is the number of radio astronomical data available through the VO. In order to facilitate the building of new radio astronomical archives, easing at the same time their interoperability with VO framework, we have developed a VO-compliant data model which provides interoperable data semantics for radio data. That model, which we call the Radio Astronomical DAta Model for Single-dish (RADAMS) has been built using standards of (and recommendations from) the International Virtual Observatory Alliance (IVOA). This article describes the RADAMS and its components, including archived entities and their relationships to VO metadata. We show that by using IVOA principles and concepts, the effort needed for both the development of the archives and their VO compatibility has been lowered, and the joint development of two radio astronomical archives have been possible. We plan to adapt RADAMS to be able to deal with interferometry data in the future.

A Solar Data Model for Use in Virtual Observatories

NASA Astrophysics Data System (ADS)

Reardon, K. P.; Bentley, R. D.; Messerotti, M.; Giordano, S.

2004-05-01

The creation of a virtual solar observatories relies heavily on the merging of the metadata describing different datasets into a common form so that it can be handled in a standard way for all associated resources. In order to bring together the varied data descriptions that already exist, it is necessary to have a common framework on which all the different datasets can be represented. The definition of this framework is done through a data model which attempts to provide a simplified but realistic description of the various entities that make up a data set or solar resource. We present the solar data model which has been developed as part of the European Grid of Solar Observations (EGSO) project. This model attempts to include many of the different elements in the field of solar physics, including data producers, data sets, event lists, and data providers. This global picture can then be used to focus on the particular elements required for a specific implementation. We present the different aspects of the model and describe some systems in which portions of this model have been implemented.

Relating Alfvén Wave Heating Model to Observations of a Solar Active Region

NASA Astrophysics Data System (ADS)

Yoritomo, J. Y.; Van Ballegooijen, A. A.

2012-12-01

We compared images from the Solar Dynamics Observatory's (SDO) Atmospheric Imaging Assembly (AIA) with simulations of propagating and dissipating Alfvén waves from a three-dimensional magnetohydrodynamic (MHD) model (van Ballegooijen et. al 2011; Asgari-Targhi & van Ballegooijen 2012). The goal was to search for observational evidence of Alfvén waves in the solar corona and understand their role in coronal heating. We looked at one particular active region on the 5th of May 2012. Certain distinct loops in the SDO/AIA observations were selected and expanded. Movies were created from these selections in an attempt to discover transverse motions that may be Alfvén waves. Using a magnetogram of that day and the corresponding synoptic map, a potential field model was created for the active region. Three-dimensional MHD models for several loops in different locations in the active region were created. Each model specifies the temperature, pressure, magnetic field strength, average heating rate, and other parameters along the loop. We find that the heating is intermittent in the loops and reflection occurs at the transition region. For loops at larger and larger height, a point is reached where thermal non-equilibrium occurs. In the center this critical height is much higher than in the periphery of the active region. Lastly, we find that the average heating rate and coronal pressure decrease with increasing height in the corona. This research was supported by an NSF grant for the Smithsonian Astrophysical Observatory (SAO) Solar REU program and a SDO/AIA grant for the Smithsonian Astrophysical Observatory.

High-Level Location Based Search Services That Improve Discoverability of Geophysical Data in the Virtual ITM Observatory

NASA Astrophysics Data System (ADS)

Schaefer, R. K.; Morrison, D.; Potter, M.; Barnes, R. J.; Nylund, S. R.; Patrone, D.; Aiello, J.; Talaat, E. R.; Sarris, T.

2015-12-01

The great promise of Virtual Observatories is the ability to perform complex search operations across the metadata of a large variety of different data sets. This allows the researcher to isolate and select the relevant measurements for their topic of study. The Virtual ITM Observatory (VITMO) has many diverse geophysical datasets that cover a large temporal and spatial range that present a unique search problem. VITMO provides many methods by which the user can search for and select data of interest including restricting selections based on geophysical conditions (solar wind speed, Kp, etc) as well as finding those datasets that overlap in time. One of the key challenges in improving discoverability is the ability to identify portions of datasets that overlap in time and in location. The difficulty is that location data is not contained in the metadata for datasets produced by satellites and would be extremely large in volume if it were available, making searching for overlapping data very time consuming. To solve this problem we have developed a series of light-weight web services that can provide a new data search capability for VITMO and others. The services consist of a database of spacecraft ephemerides and instrument fields of view; an overlap calculator to find times when the fields of view of different instruments intersect; and a magnetic field line tracing service that maps in situ and ground based measurements to the equatorial plane in magnetic coordinates for a number of field models and geophysical conditions. These services run in real-time when the user queries for data. These services will allow the non-specialist user to select data that they were previously unable to locate, opening up analysis opportunities beyond the instrument teams and specialists, making it easier for future students who come into the field.

The Research Tools of the Virtual Astronomical Observatory

NASA Astrophysics Data System (ADS)

Hanisch, Robert J.; Berriman, G. B.; Lazio, T. J.; Project, VAO

2013-01-01

Astronomy is being transformed by the vast quantities of data, models, and simulations that are becoming available to astronomers at an ever-accelerating rate. The U.S. Virtual Astronomical Observatory (VAO) has been funded to provide an operational facility that is intended to be a resource for discovery and access of data, and to provide science services that use these data. Over the course of the past year, the VAO has been developing and releasing for community use five science tools: 1) "Iris", for dynamically building and analyzing spectral energy distributions, 2) a web-based data discovery tool that allows astronomers to identify and retrieve catalog, image, and spectral data on sources of interest, 3) a scalable cross-comparison service that allows astronomers to conduct pair-wise positional matches between very large catalogs stored remotely as well as between remote and local catalogs, 4) time series tools that allow astronomers to compute periodograms of the public data held at the NASA Star and Exoplanet Database (NStED) and the Harvard Time Series Center, and 5) A VO-aware release of the Image Reduction and Analysis Facility (IRAF) that provides transparent access to VO-available data collections and is SAMP-enabled, so that IRAF users can easily use tools such as Aladin and Topcat in conjuction with IRAF tasks. Additional VAO services will be built to make it easy for researchers to provide access to their data in VO-compliant ways, to build VO-enabled custom applications in Python, and to respond generally to the growing size and complexity of astronomy data. Acknowledgements: The Virtual Astronomical Observatory (VAO) is managed by the VAO, LLC, a non-profit company established as a partnership of the Associated Universities, Inc. and the Association of Universities for Research in Astronomy, Inc. The VAO is sponsored by the National Science Foundation and the National Aeronautics and Space Administration.

The National Astronomical Observatory of Japan and Post-war Japanese Optical Astronomy

NASA Astrophysics Data System (ADS)

Tajima, Toshiyuki

This paper depicts some aspects of the formative process of the Japanese optical and infrared astronomical community in the post-war period, featuring the transition of the National Astronomical Observatory of Japan(NAOJ). We take up three cases of telescope construction, examining their background and their contribution to the Japanese astronomical community. Through these cases, the characteristics of traditions and cultures of optical and infrared astronomy in Japan are considered. Although the Tokyo Astronomical Observatory (TAO) of the University of Tokyo, the predecessor of NAOJ, was originally founded as an agency for practical astronomical observation such as time and almanac service, it has become an international centre for all types of astrophysical research. Research and development of telescopes and observational instruments have become an important part of the astronomers' practice. Now, however, a number of Japanese universities are planning to have their own large to middle-sized telescopes, and a new style of astronomical research is emerging involving astrophysical studies utilising data acquired from the Virtual Observatory, so there is a distinct possibility that the status of the NAOJ will change even further in the future.

The 2010 Polar Aeronomy and Radio Science (PARS) Summer School

DTIC Science & Technology

2011-12-30

Ionospheric Plasma ........................................................................26 3.7. Measurements of HF Wave-Induced Micropulsations Using GMOS ...facility‟s most distant diagnostic pad. This instrument, called the Geomagnetic Observatory System ( GMOS ) is capable of measuring very small...angles 3.7. Measurements of HF Wave-Induced Micropulsations Using GMOS 3.7.1. Investigators J. Gancarz, R. Pradipta, and Min-Chang Lee (Mentor

Characteristics of acoustic wave from atmospheric nuclear explosions conducted at the USSR Test Sites

NASA Astrophysics Data System (ADS)

Sokolova, Inna

2015-04-01

Availability of the acoustic wave on the record of microbarograph is one of discriminate signs of atmospheric (surface layer of atmosphere) and contact explosions. Nowadays there is large number of air wave records from chemical explosions recorded by the IMS infrasound stations installed during recent decade. But there is small number of air wave records from nuclear explosions as air and contact nuclear explosions had been conducted since 1945 to 1962, before the Limited Test Ban Treaty was signed in 1963 (the treaty banning nuclear weapon tests in the atmosphere, in outer space and under water) by the Great Britain, USSR and USA. That time there was small number of installed microbarographs. First infrasound stations in the USSR appeared in 1954, and by the moment of the USSR collapse the network consisted of 25 infrasound stations, 3 of which were located on Kazakhstan territory - in Kurchatov (East Kazakhstan), in Borovoye Observatory (North Kazakhstan) and Talgar Observatory (Northern Tien Shan). The microbarograph of Talgar Observatory was installed in 1962 and recorded large number of air nuclear explosions conducted at Semipalatinsk Test Site and Novaya Zemlya Test Site. The epicentral distance to the STS was ~700 km, and to Novaya Zemlya Test Site ~3500 km. The historical analog records of the microbarograph were analyzed on the availability of the acoustic wave. The selected records were digitized, the database of acoustic signals from nuclear explosions was created. In addition, acoustic signals from atmospheric nuclear explosions conducted at the USSR Test Sites were recorded by analogue broadband seismic stations at wide range of epicentral distances, 300-3600 km. These signals coincide well by its form and spectral content with records of microbarographs and can be used for monitoring tasks and discrimination in places where infrasound observations are absent. Nuclear explosions which records contained acoustic wave were from 0.03 to 30 kt yield for the STS, and from 8.3 to 25 Mt yield for Novaya Zemlya Test Site region. The peculiarities of the wave pattern and spectral content of the acoustic wave records, and relation regularities of acoustic wave amplitude and periods with explosion yield and distance were investigated. The created database can be applied in different monitoring tasks, such as infrasound stations calibration, discrimination of nuclear explosions, precision of nuclear explosions parameters, determination of the explosion yield etc.

The Virtual Cosmos Project: Astronomical Data access for General Public via the National Virtual Observatory

NASA Astrophysics Data System (ADS)

Craig, N.; Mendez, B. J.; Hanisch, R. J.; Christian, C. A.; Summers, F.; Haisch, B.; Lindblom, J.

2005-05-01

We will describe the development of protocols to make Astronomy press-release quality images from HST and other sources publicly available through compatibility with the National Virtual Observatory (NVO). We will present the designs for a public portal to these resources, based on a robust evaluation of our intended audience. The availability of press-release quality materials via the NVO through a simplified interface will greatly enhance the utility of these materials for the public. Behind any portal to NVO data there is a standard registry and data structures that allow collections of data (such as the press release images) to be located and acquired. We will describe our design of the necessary protocols and metadata being used within the NVO framework for this project. We base our meta-tags on the considerable existing work done in the science community as well as the NASA education community. These refined metadata are applied to new HST press-release images as they are produced and registered with the NVO. We will describe methods for retrofitting pre-existing imagery with the metadata standards. The rich media, 3D navigation and visualization capabilities of the browser created by ManyOne Network Inc. are particularly well suited to the presentation of astronomical information and ever more detailed models of the local neighborhood, the Milky Way, etc. We will discuss the 3D navigation and visualization capabilities of the browser with particular focus on the Milky Way Galaxy. Development of an online encyclopedia to accompany the ManyOne portals as part of the Virtual Cosmos will also be described. Support from NASA's AISR Program is gratefully acknowledged.

Possible Space-Based Gravitational-Wave Observatory Mission Concept

NASA Technical Reports Server (NTRS)

Livas, Jeffrey C.

2015-01-01

The existence of gravitational waves was established by the discovery of the Binary Pulsar PSR 1913+16 by Hulse and Taylor in 1974, for which they were awarded the 1983 Nobel Prize. However, it is the exploitation of these gravitational waves for the extraction of the astrophysical parameters of the sources that will open the first new astronomical window since the development of gamma ray telescopes in the 1970's and enable a new era of discovery and understanding of the Universe. Direct detection is expected in at least two frequency bands from the ground before the end of the decade with Advanced LIGO and Pulsar Timing Arrays. However, many of the most exciting sources will be continuously observable in the band from 0.1-100 mHz, accessible only from space due to seismic noise and gravity gradients in that band that disturb groundbased observatories. This talk will discuss a possible mission concept developed from the original Laser Interferometer Space Antenna (LISA) reference mission but updated to reduce risk and cost.

The Laser Interferometer Space Antenna: A space-based Gravitational Wave Observatory

NASA Astrophysics Data System (ADS)

Thorpe, James Ira; McNamara, Paul

2018-01-01

After decades of persistence, scientists have recently developed facilities which can measure the vibrations of spacetime caused by astrophysical cataclysms such as the mergers of black holes and neutron stars. The first few detections have presented some interesting astrophysical questions and it is clear that with an increase in the number and capability of ground-based facilities, gravitational waves will become an important tool for astronomy. A space-based observatory will complement these efforts by providing access to the milliHertz gravitational wave band, which is expected to be rich in both number and variety of sources. The European Space Agency (ESA) has recently selected the Laser Interferometer Space Antenna (LISA) as a Large-Class mission in its Cosmic Visions Programme. The modern LISA retains the basic design features of previous incarnations and, like its predecessors is expected to be a collaboration between ESA, NASA, and a number of European States. In this poster, we present an overview of the current LISA design, its scientific capabilities, and the timeline to launch.

Quantum correlation measurements in interferometric gravitational-wave detectors

NASA Astrophysics Data System (ADS)

Martynov, D. V.; Frolov, V. V.; Kandhasamy, S.; Izumi, K.; Miao, H.; Mavalvala, N.; Hall, E. D.; Lanza, R.; Abbott, B. P.; Abbott, R.; Abbott, T. D.; Adams, C.; Adhikari, R. X.; Anderson, S. B.; Ananyeva, A.; Appert, S.; Arai, K.; Aston, S. M.; Ballmer, S. W.; Barker, D.; Barr, B.; Barsotti, L.; Bartlett, J.; Bartos, I.; Batch, J. C.; Bell, A. S.; Betzwieser, J.; Billingsley, G.; Birch, J.; Biscans, S.; Biwer, C.; Blair, C. D.; Bork, R.; Brooks, A. F.; Ciani, G.; Clara, F.; Countryman, S. T.; Cowart, M. J.; Coyne, D. C.; Cumming, A.; Cunningham, L.; Danzmann, K.; Da Silva Costa, C. F.; Daw, E. J.; DeBra, D.; DeRosa, R. T.; DeSalvo, R.; Dooley, K. L.; Doravari, S.; Driggers, J. C.; Dwyer, S. E.; Effler, A.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fair, H.; Fernández Galiana, A.; Fisher, R. P.; Fritschel, P.; Fulda, P.; Fyffe, M.; Giaime, J. A.; Giardina, K. D.; Goetz, E.; Goetz, R.; Gras, S.; Gray, C.; Grote, H.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hammond, G.; Hanks, J.; Hanson, J.; Hardwick, T.; Harry, G. M.; Heintze, M. C.; Heptonstall, A. W.; Hough, J.; Jones, R.; Karki, S.; Kasprzack, M.; Kaufer, S.; Kawabe, K.; Kijbunchoo, N.; King, E. J.; King, P. J.; Kissel, J. S.; Korth, W. Z.; Kuehn, G.; Landry, M.; Lantz, B.; Lockerbie, N. A.; Lormand, M.; Lundgren, A. P.; MacInnis, M.; Macleod, D. M.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martin, I. W.; Mason, K.; Massinger, T. J.; Matichard, F.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McIntyre, G.; McIver, J.; Mendell, G.; Merilh, E. L.; Meyers, P. M.; Miller, J.; Mittleman, R.; Moreno, G.; Mueller, G.; Mullavey, A.; Munch, J.; Nuttall, L. K.; Oberling, J.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ottaway, D. J.; Overmier, H.; Palamos, J. R.; Paris, H. R.; Parker, W.; Pele, A.; Penn, S.; Phelps, M.; Pierro, V.; Pinto, I.; Principe, M.; Prokhorov, L. G.; Puncken, O.; Quetschke, V.; Quintero, E. A.; Raab, F. J.; Radkins, H.; Raffai, P.; Reid, S.; Reitze, D. H.; Robertson, N. A.; Rollins, J. G.; Roma, V. J.; Romie, J. H.; Rowan, S.; Ryan, K.; Sadecki, T.; Sanchez, E. J.; Sandberg, V.; Savage, R. L.; Schofield, R. M. S.; Sellers, D.; Shaddock, D. A.; Shaffer, T. J.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sigg, D.; Slagmolen, B. J. J.; Smith, B.; Smith, J. R.; Sorazu, B.; Staley, A.; Strain, K. A.; Tanner, D. B.; Taylor, R.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Torrie, C. I.; Traylor, G.; Vajente, G.; Valdes, G.; van Veggel, A. A.; Vecchio, A.; Veitch, P. J.; Venkateswara, K.; Vo, T.; Vorvick, C.; Walker, M.; Ward, R. L.; Warner, J.; Weaver, B.; Weiss, R.; Weßels, P.; Willke, B.; Wipf, C. C.; Worden, J.; Wu, G.; Yamamoto, H.; Yancey, C. C.; Yu, Hang; Yu, Haocun; Zhang, L.; Zucker, M. E.; Zweizig, J.; LSC Instrument Authors

2017-04-01

Quantum fluctuations in the phase and amplitude quadratures of light set limitations on the sensitivity of modern optical instruments. The sensitivity of the interferometric gravitational-wave detectors, such as the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO), is limited by quantum shot noise, quantum radiation pressure noise, and a set of classical noises. We show how the quantum properties of light can be used to distinguish these noises using correlation techniques. Particularly, in the first part of the paper we show estimations of the coating thermal noise and gas phase noise, hidden below the quantum shot noise in the Advanced LIGO sensitivity curve. We also make projections on the observatory sensitivity during the next science runs. In the second part of the paper we discuss the correlation technique that reveals the quantum radiation pressure noise from the background of classical noises and shot noise. We apply this technique to the Advanced LIGO data, collected during the first science run, and experimentally estimate the quantum correlations and quantum radiation pressure noise in the interferometer.

Optical Follow-up of Gravitational-wave Events with Las Cumbres Observatory

NASA Astrophysics Data System (ADS)

Arcavi, Iair; McCully, Curtis; Hosseinzadeh, Griffin; Howell, D. Andrew; Vasylyev, Sergiy; Poznanski, Dovi; Zaltzman, Michael; Maoz, Dan; Singer, Leo; Valenti, Stefano; Kasen, Daniel; Barnes, Jennifer; Piran, Tsvi; Fong, Wen-fai

2017-10-01

We present an implementation of the Gehrels et al. galaxy-targeted strategy for gravitational-wave (GW) follow-up using the Las Cumbres Observatory global network of telescopes. We use the Galaxy List for the Advanced Detector Era (GLADE) galaxy catalog, which we show is complete (with respect to a Schechter function) out to ˜300 Mpc for galaxies brighter than the median Schechter function galaxy luminosity. We use a prioritization algorithm to select the galaxies with the highest chance of containing the counterpart given their luminosity, their position, and their distance relative to a GW localization, and in which we are most likely to detect a counterpart given its expected brightness compared to the limiting magnitude of our telescopes. This algorithm can be easily adapted to any expected transient parameters and telescopes. We implemented this strategy during the second Advanced Detector Observing Run (O2) and followed the black hole merger GW170814 and the neutron star merger GW170817. For the latter, we identified an optical kilonova/macronova counterpart thanks to our algorithm selecting the correct host galaxy fifth in its ranked list among the 182 galaxies we identified in the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo localization. This also allowed us to obtain some of the earliest observations of the first optical transient ever triggered by a GW detection (as presented in a companion paper).

Optical Follow-up of Gravitational-wave Events with Las Cumbres Observatory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arcavi, Iair; McCully, Curtis; Hosseinzadeh, Griffin

We present an implementation of the Gehrels et al. galaxy-targeted strategy for gravitational-wave (GW) follow-up using the Las Cumbres Observatory global network of telescopes. We use the Galaxy List for the Advanced Detector Era (GLADE) galaxy catalog, which we show is complete (with respect to a Schechter function) out to ∼300 Mpc for galaxies brighter than the median Schechter function galaxy luminosity. We use a prioritization algorithm to select the galaxies with the highest chance of containing the counterpart given their luminosity, their position, and their distance relative to a GW localization, and in which we are most likely tomore » detect a counterpart given its expected brightness compared to the limiting magnitude of our telescopes. This algorithm can be easily adapted to any expected transient parameters and telescopes. We implemented this strategy during the second Advanced Detector Observing Run (O2) and followed the black hole merger GW170814 and the neutron star merger GW170817. For the latter, we identified an optical kilonova/macronova counterpart thanks to our algorithm selecting the correct host galaxy fifth in its ranked list among the 182 galaxies we identified in the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo localization. This also allowed us to obtain some of the earliest observations of the first optical transient ever triggered by a GW detection (as presented in a companion paper).« less

Terrorism and right-wing extremism: the changing face of terrorism and political violence in the 21st century: the virtual community of hatred.

PubMed

Post, Jerrold M

2015-04-01

There are no psychological characteristics or psychopathology that separates terrorists from the general population. Rather it is group dynamics, with a particular emphasis on collective identity that helps explain terrorist psychology. Just as there is a diverse spectrum of terrorisms, so too is there a spectrum of terrorist psychologies. Four waves of terrorism can be distinguished: the Anarchist wave, associated with labor violence in the United States in the late 19th century; the Anti-Colonial wave (nationalist-separatist), with minority groups seeking to be liberated from their colonial masters or from the majority in their country; the New Left wave (social revolutionary); and now the Religious wave. With the communications revolution, a new phenomenon is emerging which may presage a fifth wave: lone wolf terrorists who through the Internet are radicalized and feel they belong to the virtual community of hatred. A typology of lone wolf terrorism is proposed.

Solar Demon: near real-time Flare, Dimming and EUV wave monitoring

NASA Astrophysics Data System (ADS)

Kraaikamp, Emil; Verbeeck, Cis

Dimmings and EUV waves have been observed routinely in EUV images since 1996. They are closely associated with coronal mass ejections (CMEs), and therefore provide useful information for early space weather alerts. On the one hand, automatic detection and characterization of dimmings and EUV waves can be used to gain better understanding of the underlying physical mechanisms. On the other hand, every dimming and EUV wave provides extra information on the associated front side CME, and can improve estimates of the geo-effectiveness and arrival time of the CME. Solar Demon has been designed to detect and characterize dimmings, EUV waves, as well as solar flares in near real-time on Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) data. The detection modules are running continuously at the Royal Observatory of Belgium on both quick-look data, as well as synoptic science data. The output of Solar Demon can be accessed in near real-time on the Solar Demon website, and includes images, movies, light curves, and the numerical evolution of several parameters. Solar Demon is the result of collaboration between the FP7 projects AFFECTS and COMESEP. Flare detections of Solar Demon are integrated into the COMESEP alert system. Here we present the Solar Demon detection algorithms and their output. We will show several interesting flare, dimming and EUV wave events, and present general statistics of the detections made so far during solar cycle 24.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Pankaj; Innes, D. E.; Inhester, B., E-mail: pankaj@kasi.re.kr

We report high resolution observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) of intensity oscillations in a hot, T ∼ 8-10 MK, loop. The AIA images show a large coronal loop that was rapidly heated following plasma ejection from one of the loop's footpoints. A wave-like intensity enhancement, seen very clearly in the 131 and 94 Å channel images, propagated ahead of the ejecta along the loop, and was reflected at the opposite footpoint. The wave reflected four times before fading. It was only seen in the hot, 131 and 94 Å channels. The characteristic period and the decaymore » time of the oscillation were ∼630 and ∼440 s, respectively. The phase speed was about 460-510 km s{sup –1} which roughly matches the sound speed of the loop (430-480 km s{sup –1}). The observed properties of the oscillation are consistent with the observations of Dopper-shift oscillations discovered by the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation and with their interpretation as slow magnetoacoustic waves. We suggest that the impulsive injection of plasma, following reconnection at one of the loop footpoints, led to rapid heating and the propagation of a longitudinal compressive wave along the loop. The wave bounces back and forth a couple of times before fading.« less

Observations of the Breakdown of Mountain Waves Over the Andes Lidar Observatory at Cerro Pachon on 8/9 July 2012

NASA Astrophysics Data System (ADS)

Hecht, J. H.; Fritts, D. C.; Wang, L.; Gelinas, L. J.; Rudy, R. J.; Walterscheid, R. L.; Taylor, M. J.; Pautet, P. D.; Smith, S.; Franke, S. J.

2018-01-01

Although mountain waves (MWs) are thought to be a ubiquitous feature of the wintertime southern Andes stratosphere, it was not known whether these waves propagated up to the mesopause region until Smith et al. (2009) confirmed their presence via airglow observations. The new Andes Lidar Observatory at Cerro Pachon in Chile provided the opportunity for a further study of these waves. Since MWs have near-zero phase speed, and zero wind lines often occur in the winter upper mesosphere (80 to 100 km altitude) region due to the reversal of the zonal mean and tidal wind, MW breakdown may routinely occur at these altitudes. Here we report on very high spatial/temporal resolution observations of the initiation of MW breakdown in the mesopause region. Because the waves are nearly stationary, the breakdown process was observed over several hours; a much longer interval than has previously been observed for any gravity wave breakdown. During the breakdown process observations were made of initial horseshoe-shaped vortices, leading to successive vortex rings, as is also commonly seen in Direct Numerical Simulations (DNS) of idealized and multiscale gravity wave breaking. Kelvin-Helmholtz instability (KHI) structures were also observed to form. Comparing the structure of observed KHI with the results of existing DNS allowed an estimate of the turbulent kinematic viscosity. This viscosity was found to be around 25 m2/s, a value larger than the nominal viscosity that is used in models.

The detection of upwardly propagating waves channeling energy from the chromosphere to the low corona

DOE Office of Scientific and Technical Information (OSTI.GOV)

Freij, N.; Nelson, C. J.; Mumford, S.

There have been ubiquitous observations of wave-like motions in the solar atmosphere for decades. Recent improvements to space- and ground-based observatories have allowed the focus to shift to smaller magnetic structures on the solar surface. In this paper, high-resolution ground-based data taken using the Swedish 1 m Solar Telescope is combined with co-spatial and co-temporal data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) satellite to analyze running penumbral waves (RPWs). RPWs have always been thought to be radial wave propagation that occurs within sunspots. Recent research has suggested that they are in fact upwardlymore » propagating field-aligned waves (UPWs). Here, RPWs within a solar pore are observed for the first time and are interpreted as UPWs due to the lack of a penumbra that is required to support RPWs. These UPWs are also observed co-spatially and co-temporally within several SDO/AIA elemental lines that sample the transition region and low corona. The observed UPWs are traveling at a horizontal velocity of around 17 ± 0.5 km s{sup –1} and a minimum vertical velocity of 42 ± 21 km s{sup –1}. The estimated energy of the waves is around 150 W m{sup –2}, which is on the lower bound required to heat the quiet-Sun corona. This is a new, yet unconsidered source of wave energy within the solar chromosphere and low corona.« less

Communicating Wave Energy: An Active Learning Experience for Students

ERIC Educational Resources Information Center

Huynh, Trongnghia; Hou, Gene; Wang, Jin

2016-01-01

We have conducted an education project to communicate the wave energy concept to high school students. A virtual reality system that combines both hardware and software is developed in this project to simulate the buoy-wave interaction. This first-of-its-kind wave energy unit is portable and physics-based, allowing students to conduct a number of…

Combining virtual observatory and equivalent source dipole approaches to describe the geomagnetic field with Swarm measurements

NASA Astrophysics Data System (ADS)

Saturnino, Diana; Langlais, Benoit; Amit, Hagay; Civet, François; Mandea, Mioara; Beucler, Éric

2018-03-01

A detailed description of the main geomagnetic field and of its temporal variations (i.e., the secular variation or SV) is crucial to understanding the geodynamo. Although the SV is known with high accuracy at ground magnetic observatory locations, the globally uneven distribution of the observatories hampers the determination of a detailed global pattern of the SV. Over the past two decades, satellites have provided global surveys of the geomagnetic field which have been used to derive global spherical harmonic (SH) models through some strict data selection schemes to minimise external field contributions. However, discrepancies remain between ground measurements and field predictions by these models; indeed the global models do not reproduce small spatial scales of the field temporal variations. To overcome this problem we propose to directly extract time series of the field and its temporal variation from satellite measurements as it is done at observatory locations. We follow a Virtual Observatory (VO) approach and define a global mesh of VOs at satellite altitude. For each VO and each given time interval we apply an Equivalent Source Dipole (ESD) technique to reduce all measurements to a unique location. Synthetic data are first used to validate the new VO-ESD approach. Then, we apply our scheme to data from the first two years of the Swarm mission. For the first time, a 2.5° resolution global mesh of VO time series is built. The VO-ESD derived time series are locally compared to ground observations as well as to satellite-based model predictions. Our approach is able to describe detailed temporal variations of the field at local scales. The VO-ESD time series are then used to derive global spherical harmonic models. For a simple SH parametrization the model describes well the secular trend of the magnetic field both at satellite altitude and at the surface. As more data will be made available, longer VO-ESD time series can be derived and consequently used to study sharp temporal variation features, such as geomagnetic jerks.

Investigating the Wave Nature of the Outer Envelope of Halo Coronal Mass Ejections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, Ryun-Young; Vourlidas, Angelos, E-mail: rkwon@gmu.edu

We investigate the nature of the outer envelope of halo coronal mass ejections (H-CMEs) using multi-viewpoint observations from the Solar Terrestrial Relations Observatory-A , -B , and SOlar and Heliospheric Observatory coronagraphs. The 3D structure and kinematics of the halo envelopes and the driving CMEs are derived separately using a forward modeling method. We analyze three H-CMEs with peak speeds from 1355 to 2157 km s{sup −1}; sufficiently fast to drive shocks in the corona. We find that the angular widths of the halos range from 192° to 252°, while those of the flux ropes range between only 58° andmore » 91°, indicating that the halos are waves propagating away from the CMEs. The halo widths are in agreement with widths of Extreme Ultraviolet (EUV) waves in the low corona further demonstrating the common origin of these structures. To further investigate the wave nature of the halos, we model their 3D kinematic properties with a linear fast magnetosonic wave model. The model is able to reproduce the position of the halo flanks with realistic coronal medium assumptions but fails closer to the CME nose. The CME halo envelope seems to arise from a driven wave (or shock) close to the CME nose, but it is gradually becoming a freely propagating fast magnetosonic wave at the flanks. This interpretation provides a simple unifying picture for CME halos, EUV waves, and the large longitudinal spread of solar energetic particles.« less

Observatories Combine to Crack Open the Crab Nebula

NASA Image and Video Library

2017-12-08

Astronomers have produced a highly detailed image of the Crab Nebula, by combining data from telescopes spanning nearly the entire breadth of the electromagnetic spectrum, from radio waves seen by the Karl G. Jansky Very Large Array (VLA) to the powerful X-ray glow as seen by the orbiting Chandra X-ray Observatory. And, in between that range of wavelengths, the Hubble Space Telescope's crisp visible-light view, and the infrared perspective of the Spitzer Space Telescope. This composite image of the Crab Nebula, a supernova remnant, was assembled by combining data from five telescopes spanning nearly the entire breadth of the electromagnetic spectrum: the Very Large Array, the Spitzer Space Telescope, the Hubble Space Telescope, the XMM-Newton Observatory, and the Chandra X-ray Observatory. Credits: NASA, ESA, NRAO/AUI/NSF and G. Dubner (University of Buenos Aires) #nasagoddard #space #science

Real and Virtual Heritage - The Plate Archive of Sonneberg Observatory - Digitisation, Preservation and Scientific Programme

NASA Astrophysics Data System (ADS)

Kroll, Peter

The real heritage of Sonneberg Observatory consists of several buildings with seven domes, a number of telescopes for photographic and photoelectric measurements, a plate archive - which is the second-largest in the world - and a scientific library. While the instruments are today mainly used for public observing tours and to a limited degree for continuing sky patrol, the plate archive is systematically scanned in order to make the whole information stored in the emulsion of the plates accessible to the astronomical community and to allow the scientific study of all stars ever recorded. First pilot studies give a taste of what output can be expected from the digitized plate archive.

Space-weather assets developed by the French space-physics community

NASA Astrophysics Data System (ADS)

Rouillard, A. P.; Pinto, R. F.; Brun, A. S.; Briand, C.; Bourdarie, S.; Dudok De Wit, T.; Amari, T.; Blelly, P.-L.; Buchlin, E.; Chambodut, A.; Claret, A.; Corbard, T.; Génot, V.; Guennou, C.; Klein, K. L.; Koechlin, L.; Lavarra, M.; Lavraud, B.; Leblanc, F.; Lemorton, J.; Lilensten, J.; Lopez-Ariste, A.; Marchaudon, A.; Masson, S.; Pariat, E.; Reville, V.; Turc, L.; Vilmer, N.; Zucarello, F. P.

2016-12-01

We present a short review of space-weather tools and services developed and maintained by the French space-physics community. They include unique data from ground-based observatories, advanced numerical models, automated identification and tracking tools, a range of space instrumentation and interconnected virtual observatories. The aim of the article is to highlight some advances achieved in this field of research at the national level over the last decade and how certain assets could be combined to produce better space-weather tools exploitable by space-weather centres and customers worldwide. This review illustrates the wide range of expertise developed nationally but is not a systematic review of all assets developed in France.

VizieR Online Data Catalog: H2CO and CO in 4 molecular clouds (Tang+, 2013)

NASA Astrophysics Data System (ADS)

Tang, X. D.; Esimbek, J.; Zhou, J. J.; Wu, G.; Ji, W. G.; Okoh, D.

2017-11-01

From September 2010 to August 2011, we observed the H2CO lin H110α line, and the 6cm continuum with the Nanshan 25m radio telescope of Xinjiang Astronomical Observatory. >From 15 to 26 May 2011, the 12CO and 13CO observations of the four regions were carried out with the 13.7m millimeter wave telescope of Purple Mountain Observatory in Delingha. (4 data files).

AstroCloud, a Cyber-Infrastructure for Astronomy Research: Data Access and Interoperability

NASA Astrophysics Data System (ADS)

Fan, D.; He, B.; Xiao, J.; Li, S.; Li, C.; Cui, C.; Yu, C.; Hong, Z.; Yin, S.; Wang, C.; Cao, Z.; Fan, Y.; Mi, L.; Wan, W.; Wang, J.

2015-09-01

Data access and interoperability module connects the observation proposals, data, virtual machines and software. According to the unique identifier of PI (principal investigator), an email address or an internal ID, data can be collected by PI's proposals, or by the search interfaces, e.g. conesearch. Files associated with the searched results could be easily transported to cloud storages, including the storage with virtual machines, or several commercial platforms like Dropbox. Benefitted from the standards of IVOA (International Observatories Alliance), VOTable formatted searching result could be sent to kinds of VO software. Latter endeavor will try to integrate more data and connect archives and some other astronomical resources.

Gravitational-wave stochastic background from cosmic strings.

PubMed

Siemens, Xavier; Mandic, Vuk; Creighton, Jolien

2007-03-16

We consider the stochastic background of gravitational waves produced by a network of cosmic strings and assess their accessibility to current and planned gravitational wave detectors, as well as to big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and pulsar timing constraints. We find that current data from interferometric gravitational wave detectors, such as Laser Interferometer Gravitational Wave Observatory (LIGO), are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds. Future more sensitive LIGO runs and interferometers such as Advanced LIGO and Laser Interferometer Space Antenna (LISA) will be able to explore substantial parts of the parameter space.

The methodology of the search for a correlated signal from a supernova explosion using the data of gravitational wave detectors and neutrino observatories

NASA Astrophysics Data System (ADS)

Gromov, M. B.

2017-11-01

The proposed methodology developed in cooperation of the LIGO, VIRGO, Borexino, LVD, and IceCube collaborations is based on a joint analysis of data from neutrino and gravitational wave detectors which record corresponding radiations, almost undistorted by the interstellar medium and propagating with similar speeds. This approach allows to increase the reliability of observations, detect the so-called Silent supernovae and explore the properties and generation mechanisms of gravitational waves.

Rapid Monte Carlo Simulation of Gravitational Wave Galaxies

NASA Astrophysics Data System (ADS)

Breivik, Katelyn; Larson, Shane L.

2015-01-01

With the detection of gravitational waves on the horizon, astrophysical catalogs produced by gravitational wave observatories can be used to characterize the populations of sources and validate different galactic population models. Efforts to simulate gravitational wave catalogs and source populations generally focus on population synthesis models that require extensive time and computational power to produce a single simulated galaxy. Monte Carlo simulations of gravitational wave source populations can also be used to generate observation catalogs from the gravitational wave source population. Monte Carlo simulations have the advantes of flexibility and speed, enabling rapid galactic realizations as a function of galactic binary parameters with less time and compuational resources required. We present a Monte Carlo method for rapid galactic simulations of gravitational wave binary populations.

Statistical comparisons of gravity wave features derived from OH airglow and SABER data

NASA Astrophysics Data System (ADS)

Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.

2017-12-01

The Aerospace Corporation's near-IR camera (ANI), deployed at Andes Lidar Observatory (ALO), Cerro Pachon Chile (30S,70W) since 2010, images the bright OH Meinel (4,2) airglow band. The imager provides detailed observations of gravity waves and instability dynamics, as described by Hecht et al. (2014). The camera employs a wide-angle lens that views a 73 by 73 degree region of the sky, approximately 120 km x 120 km at 85 km altitude. Image cadence of 30s allows for detailed spectral analysis of the horizontal components of wave features, including the evolution and decay of instability features. The SABER instrument on NASA's TIMED spacecraft provides remote soundings of kinetic temperature profiles from the lower stratosphere to the lower thermosphere. Horizontal and vertical filtering techniques allow SABER temperatures to be analyzed for gravity wave variances [Walterscheid and Christensen, 2016]. Here we compare the statistical characteristics of horizontal wave spectra, derived from airglow imagery, with vertical wave variances derived from SABER temperature profiles. The analysis is performed for a period of strong mountain wave activity over the Andes spanning the period between June and September 2012. Hecht, J. H., et al. (2014), The life cycle of instability features measured from the Andes Lidar Observatory over Cerro Pachon on March 24, 2012, J. Geophys. Res. Atmos., 119, 8872-8898, doi:10.1002/2014JD021726. Walterscheid, R. L., and A. B. Christensen (2016), Low-latitude gravity wave variances in the mesosphere and lower thermosphere derived from SABER temperature observation and compared with model simulation of waves generated by deep tropical convection, J. Geophys. Res. Atmos., 121, 11,900-11,912, doi:10.1002/2016JD024843.

MINERVA: A Dedicated Observatory for Detection of Nearby Low-Mass Exoplanets

NASA Astrophysics Data System (ADS)

McCrady, Nate; Johnson, John; Wright, Jason; Wittenmyer, Robert A.; Blake, Cullen; Swift, Jonathan; Eastman, Jason D.; Plavchan, Peter; Riddle, Reed L.; Muirhead, Philip Steven; Bottom, Michael; Zhao, Ming; Beatty, Thomas G.

2015-01-01

Detection of low-mass planets around GKM stars requires sub-meter-per-second radial velocity precision. Stellar noise sources (starspots, oscillations, and granulation) necessitate high cadence observations. MINERVA is a dedicated observatory for velocimetric detection of low mass exoplanets orbiting nearby stars. Our array of four robotic 0.7-meter PlaneWave telescopes feeds a purpose-built, temperature-stabilized, iodine cell spectrometer from Callaghan Innovation. We will monitor bright, sun-like stars within 100 pc every clear night from Whipple Observatory on Mt Hopkins, Arizona. Each telescope is also equipped with an Andor CCD for followup photometry and education use. Commissioning is underway on the site and science observations will begin in early 2015.

The Next Century Astrophysics Program

NASA Technical Reports Server (NTRS)

Swanson, Paul N.

1991-01-01

The Astrophysics Division within the NASA Office of Space Science and Applications (OSSA) has defined a set of major and moderate missions that are presently under study for flight sometime within the next 20 years. These programs include the: Advanced X Ray Astrophysics Facility; X Ray Schmidt Telescope; Nuclear Astrophysics Experiment; Hard X Ray Imaging Facility; Very High Throughput Facility; Gamma Ray Spectroscopy Observatory; Hubble Space Telescope; Lunar Transit Telescope; Astrometric Interferometer Mission; Next Generation Space Telescope; Imaging Optical Interferometer; Far Ultraviolet Spectroscopic Explorer; Gravity Probe B; Laser Gravity Wave Observatory in Space; Stratospheric Observatory for Infrared Astronomy; Space Infrared Telescope Facility; Submillimeter Intermediate Mission; Large Deployable Reflector; Submillimeter Interferometer; and Next Generation Orbiting Very Long Baseline Interferometer.

The lower ionosphere response to its disturbances by powerful radio waves

NASA Astrophysics Data System (ADS)

Bakhmetieva, N. V.; Frolov, V. L.; Vyakhirev, V. D.; Kalinina, E. E.; Akchurin, A. D.; Zykov, E. Yu.

2018-04-01

The paper presents data from some campaigns at Sura heating facility in 2011-1016. The experiments on probing of the artificial disturbed region of the lower ionosphere were carried out at two observation sites. One of them was located near Vasil'sursk 1 km from Sura facility (56.1°N; 46.1°E) and the other site was located at the Observatory (55.85°N; 48.8°E) of Kazan State University, 170 km to the East. Investigation of the features of the disturbed region of the lower ionosphere based on its diagnostics by the methods of the vertical sounding and oblique backscattering is the main goal of this paper. Ionosphere disturbance was fulfilled by the effect of the powerful radio wave of the ordinary or extraordinary polarization emitted by transmitters of the Sura facility with effective radiated power ERP = 50-120 MW at the frequency of 4.3, 4.7 and 5.6 MHz. Pumping waves were emitted with period from 30 s to 15 min. The disturbed region of the ionosphere in Vasil'sursk was probed by the vertical sounding technique using the partial reflexion radar at the frequency of 2.95 and 4.7 MHz. For the oblique sounding of the disturbed region the modified ionosonde Cyclon-M, operating at ten frequencies from 2.01 to 6.51 MHz was used at the Observatory site. On many heating sessions simultaneous variations of the probing partial reflection signals in Vasil'sursk and backscattered signals in Observatory were observed at the height at 40-100 km below the reflection height of the pumping wave. These observations were correlated with the pumping periods of the Sura facility. Possible mechanisms of the appearance of the disturbance in the lower ionosphere and its effect on the probing radio waves are discussed.

A Deep-Ocean Observatory with Near Real-time Telemetry

NASA Astrophysics Data System (ADS)

Berger, J.; Orcutt, J. A.; Laske, G.

2014-12-01

We describe an autonomously deployable, deep-ocean observatory designed to provide long term and near-real-time observations from sites far offshore. The key feature of this new system is its ability to telemeter sensor data from the seafloor to shore without a cable or moored surface buoy. In the future the observatory will be deployable without a ship. The first application of this system is seismology. While permanent ocean seismic stations on the seafloor have long been a goal of global seismology, today there are still no ocean bottom stations in the Global Seismographic Network, mostly for reasons of life-cycle costs. Yet real-time data from stations in oceanic areas are critical for both national and international agencies in monitoring and characterizing earthquakes, tsunamis, and nuclear explosions. The system comprises an ocean bottom instrumentation package and a free-floating surface communications gateway, which uses a Liquid Robotics wave glider. The glider consists of a surfboard-sized float propelled by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave gliders are equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Wave gliders have demonstrated trans-oceanic range combined with long-term station holding. The 'communications gateway,' which provides the means of communicating between the ocean bottom package and land comprises a wave glider and a towed acoustic communications 'tow body'. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land is provided by the Iridium satellite constellation. Tests of the surface gateway in 4350 m of water demonstrated the ability to send four channels of compressed 24-bit, 1 sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.2 W.

Beyond concordance cosmology with magnification of gravitational-wave standard sirens.

PubMed

Camera, Stefano; Nishizawa, Atsushi

2013-04-12

We show how future gravitational-wave detectors would be able to discriminate between the concordance Λ cold dark matter cosmological model and up-to-date competing alternatives, e.g., dynamical dark energy (DE) models or modified gravity (MG) theories. Our method consists of using the weak-lensing magnification effect that affects a standard-siren signal because of its traveling through the Universe's large scale structure. As a demonstration, we present constraints on DE and MG from proposed gravitational-wave detectors, namely Einstein Telescope and DECI-Hertz Interferometer Gravitational-Wave Observatory and Big-Bang Observer.

The Classical and Quantum Aspects of the Detection of Gravitational Waves

NASA Astrophysics Data System (ADS)

Factourovich, Maxim

Detection of gravitational waves has been one of the major undertakings of science for the past several decades. The elusive phenomenon first emerged as a natural consequence of the A. Einstein's Theory of General Relativity, but for many years was beyond the reach of the existing technological capabilities. Today, a radical effort is underway to take the measurement technology to a new, unprecedented level of sensitivity, in order to give a definite answer to one of the most fundamental aspects of our understanding of the Universe. The currently accepted detection scheme utilizes interference of near-infrared light inside a high-finesse Fabry-Perot cavity, and has achieved resolution on a scale of 10-21 as compared to the cavity length. At this scale, the signal becomes very sensitive to all kinds of unwanted inputs which include, but not limited to, the seismic activity, acoustic vibrations, thermal effects and radiation pressure noise. Moreover, the sensitivity requirements place it near the fundamental limit of quantum uncertainty which poses the ultimate barrier for lowering the detection threshold. Additionally, at the large kilometer-scale size of the installations, the signal propagation delays become significant enough to call for precise synchronization between the remote sensors and electronics within the main data collector. The need for this becomes even more evident considering a possibility of triangulation the otherwise non-directional signal, by unifying the data collected from different observatories spread around the globe. In this work, we first address the aspect of precise timing synchronization implemented in the US-based Advanced Laser-Interferometer Gravitational-wave Observatories (LIGO) located at Hanford, WA and Livingston, LA. The developed Advanced LIGO Timing System allows for synchronization of virtually unlimited number of devices to an accuracy of better than 1 microsecond, regardless of the distances involved. The machinery uses Field Programmable Gate Array (FPGA) logic at its core processing units. The FPGA chips are driven by oscillators synchronized to both, a Master atomic clock and the Global Positioning System (GPS) satellites for a precise calibration with redundancy. The timings signals are encoded in a pulse-modulated signal and distributed over the network via optical fibers. Additionally, we present a prototype device that allows overcoming the quantum sensitivity barrier without violating the Uncertainty Principle, also known as the Squeezer. We demonstrate the laser shotnoise reduction of up to 9 dB in a test setup, that eventually translated to a 25% increase in the detector sensitivity, upon injection of the squeezed light into the operational LIGO interferometer.

Predicting Binary Black Hole Collisions Using Numerical Methods in Collaboration with LIGO

NASA Astrophysics Data System (ADS)

Afshari, Nousha; Lovelace, Geoffrey

2015-04-01

Detecting astronomical gravitational waves will soon open a new window on the universe. The effects of gravitational waves have already been seen indirectly, but a direct observation of these waves will test Einstein's theory of general relativity under the most extreme conditions. The Laser Interferometer Gravitational-Wave Observatory, or LIGO, will soon begin searching for gravitational waves, and the first direct detections are likely in the next few years. To help LIGO detect as many gravitational waves as possible, a major research effort is underway to accurately predict the expected waves. In this presentation, I will discuss new supercomputer simulations of merging black holes--some of the brightest sources of gravitational waves--that I have completed using the Spectral Einstein Code (http://www.black-holes.org/SpEC.html).

Black Hole Jets Make Shock Waves

NASA Image and Video Library

2014-07-02

A composite image of the spiral galaxy NGC 4258 showing X-ray emission observed with NASA Chandra X-ray Observatory blue and infrared emission observed with NASA Spitzer Space Telescope red and green.

Data Services Upgrade: Perfecting the ISIS-I Topside Digital Ionogram Database

NASA Technical Reports Server (NTRS)

Wang, Yongli; Benson, Robert F.; Bilitza, Dieter; Fung, Shing. F.; Chu, Philip; Huang, Xueqin; Truhlik, Vladimir

2015-01-01

The ionospheric topside sounders of the International Satellites for Ionospheric Studies (ISIS) program were designed as analog systems. More than 16,000 of the original telemetry tapes from three satellites were used to produce topside digital ionograms, via an analog-to-digital (A/D) conversion process, suitable for modern analysis techniques. Unfortunately, many of the resulting digital topside ionogram files could not be auto-processed to produce topside Ne(h) profiles because of problems encountered during the A/D process. Software has been written to resolve these problems and here we report on (1) the first application of this software to a significant portion of the ISIS-1 digital topside-ionogram database, (2) software improvements motivated by this activity, (3) N(sub e)(h) profiles automatically produced from these corrected ISIS-1 digital ionogram files, and (4) the availability via the Virtual Wave Observatory (VWO) of the corrected ISIS-1 digital topside ionogram files for research. We will also demonstrate the use of these N(sub e)(h) profiles for making refinements in the International Reference Ionosphere (IRI) and in the determination of transition heights from Oxygen ion to Hydrogen ion.

Radio Jove: Citizen Science for Jupiter Radio Astronomy

NASA Astrophysics Data System (ADS)

Higgins, C. A.; Thieman, J.; Reyes, F. J.; Typinski, D.; Flagg, R. F.; Greenman, W.; Brown, J.; Ashcraft, T.; Sky, J.; Cecconi, B.; Garcia, L. N.

2016-12-01

The Radio Jove Project (http://radiojove.gsfc.nasa.gov) has been operating as an educational activity for 18 years to introduce radio astronomy activities to students, teachers, and the general public. Participants may build a simple radio telescope kit, make scientific observations, and interact with radio observatories in real-time over the Internet. Recently some of our dedicated citizen science observers have upgraded their systems to better study radio emission from Jupiter and the Sun by adding dual-polarization spectrographs and wide-band antennas in the frequency range of 15-30 MHz. Some of these observations are being used in conjunction with professional telescopes such as the Long Wavelength Array (LWA), the Nancay Decametric Array, and the Ukrainian URAN2 Radio Telescope. In particular, there is an effort to support the Juno Mission radio waves instrument at Jupiter by using citizen science ground-based data for comparison and polarization verification. These data will be archived through a Virtual European Solar and Planetary Access (VESPA) archive (https://voparis-radiojove.obspm.fr/radiojove/welcome) for use by the amateur and professional radio science community. We overview the program and display recent observations that will be of interest to the science community.

Controlled-source seismic interferometry with one way wave fields

NASA Astrophysics Data System (ADS)

van der Neut, J.; Wapenaar, K.; Thorbecke, J. W.

2008-12-01

In Seismic Interferometry we generally cross-correlate registrations at two receiver locations and sum over an array of sources to retrieve a Green's function as if one of the receiver locations hosts a (virtual) source and the other receiver location hosts an actual receiver. One application of this concept is to redatum an area of surface sources to a downhole receiver location, without requiring information about the medium between the sources and receivers, thus providing an effective tool for imaging below complex overburden, which is also known as the Virtual Source method. We demonstrate how elastic wavefield decomposition can be effectively combined with controlled-source Seismic Interferometry to generate virtual sources in a downhole receiver array that radiate only down- or upgoing P- or S-waves with receivers sensing only down- or upgoing P- or S- waves. For this purpose we derive exact Green's matrix representations from a reciprocity theorem for decomposed wavefields. Required is the deployment of multi-component sources at the surface and multi- component receivers in a horizontal borehole. The theory is supported with a synthetic elastic model, where redatumed traces are compared with those of a directly modeled reflection response, generated by placing active sources at the virtual source locations and applying elastic wavefield decomposition on both source and receiver side.

The COROT Archive at LAEFF

NASA Astrophysics Data System (ADS)

Velasco, Almudena; Gutiérrez, Raúl; Solano, Enrique; García-Torres, Miguel; López, Mauro; Sarro, Luis Manuel

We describe here the main capabilities of the COROT archive. The archive (http://sdc.laeff.inta.es/corotfa/jsp/searchform.jsp), managed at LAEFF in the framework of the Spanish Virtual Observatory (http://svo.laeff.inta.es), has been developed following the standards and requirements defined by IVOA (http://www.ivoa.net). The COROT archive at LAEFF will be publicly available by the end of 2008.

Nebula observations. Catalogues and archive of photoplates

NASA Astrophysics Data System (ADS)

Shlyapnikov, A. A.; Smirnova, M. A.; Elizarova, N. V.

2017-12-01

A process of data systematization based on "Academician G.A. Shajn's Plan" for studying the Galaxy structure related to nebula observations is considered. The creation of digital versions of catalogues of observations and publications is described, as well as their presentation in HTML, VOTable and AJS formats and basic principles of work in the interactive application of International Virtual Observatory the Aladin Sky Atlas.

A Virtual Tour of the Radio Astronomy Process

NASA Astrophysics Data System (ADS)

Conrad, S. B.; Finley, D. G.; Claussen, M. J.; Ulvestad, J. S.

2000-12-01

In the summer of 2000, two teachers working on a Masters of Science Teaching Degree at New Mexico Tech and participating in the Research Experience for Teachers (RET) program sponsored by the National Science Foundation, spent eight weeks as interns researching and working on projects at the National Radio Astronomy Observatory (NRAO) which will directly benefit students in their classrooms and also impact other science educators. One of the products of the interships is a set of web pages for NRAO's web page educational section. The purpose of these web pages is to familiarize students, teachers, and other people with the process that a radio astronomer goes through to do radio astronomy science. A virtual web tour was created of this process. This required interviewing radio astronomers and other professionals involved with this process at the NRAO (e.g. engineers, data analysts, and operations people), and synthesizing the interviews into a descriptive, visual-based set of web pages. These pages do meet the National as well as New Mexico Standards and Benchmarks for Science Education. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. The NSF's RET program is gratefully acknowledged.

Neural networks in astronomy.

PubMed

Tagliaferri, Roberto; Longo, Giuseppe; Milano, Leopoldo; Acernese, Fausto; Barone, Fabrizio; Ciaramella, Angelo; De Rosa, Rosario; Donalek, Ciro; Eleuteri, Antonio; Raiconi, Giancarlo; Sessa, Salvatore; Staiano, Antonino; Volpicelli, Alfredo

2003-01-01

In the last decade, the use of neural networks (NN) and of other soft computing methods has begun to spread also in the astronomical community which, due to the required accuracy of the measurements, is usually reluctant to use automatic tools to perform even the most common tasks of data reduction and data mining. The federation of heterogeneous large astronomical databases which is foreseen in the framework of the astrophysical virtual observatory and national virtual observatory projects, is, however, posing unprecedented data mining and visualization problems which will find a rather natural and user friendly answer in artificial intelligence tools based on NNs, fuzzy sets or genetic algorithms. This review is aimed to both astronomers (who often have little knowledge of the methodological background) and computer scientists (who often know little about potentially interesting applications), and therefore will be structured as follows: after giving a short introduction to the subject, we shall summarize the methodological background and focus our attention on some of the most interesting fields of application, namely: object extraction and classification, time series analysis, noise identification, and data mining. Most of the original work described in the paper has been performed in the framework of the AstroNeural collaboration (Napoli-Salerno).

VirGO: A Visual Browser for the ESO Science Archive Facility

NASA Astrophysics Data System (ADS)

Chéreau, F.

2008-08-01

VirGO is the next generation Visual Browser for the ESO Science Archive Facility developed by the Virtual Observatory (VO) Systems Department. It is a plug-in for the popular open source software Stellarium adding capabilities for browsing professional astronomical data. VirGO gives astronomers the possibility to easily discover and select data from millions of observations in a new visual and intuitive way. Its main feature is to perform real-time access and graphical display of a large number of observations by showing instrumental footprints and image previews, and to allow their selection and filtering for subsequent download from the ESO SAF web interface. It also allows the loading of external FITS files or VOTables, the superimposition of Digitized Sky Survey (DSS) background images, and the visualization of the sky in a `real life' mode as seen from the main ESO sites. All data interfaces are based on Virtual Observatory standards which allow access to images and spectra from external data centers, and interaction with the ESO SAF web interface or any other VO applications supporting the PLASTIC messaging system. The main website for VirGO is at http://archive.eso.org/cms/virgo.

Multiband Study of Radio Sources of the Rcr Catalogue with Virtual Observatory Tools

NASA Astrophysics Data System (ADS)

Zhelenkova, O. P.; Soboleva, N. S.; Majorova, E. K.; Temirova, A. V.

We present early results of our multiband study of the RATAN Cold Revised (RCR) catalogue obtained from seven cycles of the ``Cold'' survey carried with the RATAN-600 radio telescope at 7.6 cm in 1980--1999, at the declination of the SS 433 source. We used the 2MASS and LAS UKIDSS infrared surveys, the DSS-II and SDSS DR7 optical surveys, as well as the USNO-B1 and GSC-II catalogues, the VLSS, TXS, NVSS, FIRST and GB6 radio surveys to accumulate information about the sources. For radio sources that have no detectable optical candidate in optical or infrared catalogues, we additionally looked through images in several bands from the SDSS, LAS UKIDSS, DPOSS, 2MASS surveys and also used co-added frames in different bands. We reliably identified 76% of radio sources of the RCR catalogue. We used the ALADIN and SAOImage DS9 scripting capabilities, interoperability services of ALADIN and TOPCAT, and also other Virtual Observatory (VO) tools and resources, such as CASJobs, NED, Vizier, and WSA, for effective data access, visualization and analysis. Without VO tools it would have been problematic to perform our study.

Things That Work: Roles and Services of SPDF

NASA Technical Reports Server (NTRS)

McGuire, R. E.; Bilitza, D.; Candey, R. M.; Chimiak, R. A.; Cooper, J. F.; Garcia, L. N.; Han, D. B.; Harris, B. T.; Johnson, R. C.; King, J. H.;

PVOL: The Planetary Virtual Observatory & Laboratory. An online database of the Outer Planets images.

NASA Astrophysics Data System (ADS)

Morgado, A.; Sánchez-Lavega, A.; Rojas, J. F.; Hueso, R.

2005-08-01

The collaboration between amateurs astronomers and the professional community has been fruitful on many areas of astronomy. The development of the Internet has allowed a better than ever capability of sharing information worldwide and access to other observers data. For many years now the International Jupiter Watch (IJW) Atmospheric discipline has coordinated observational efforts for long-term studies of the atmosphere of Jupiter. The International Outer Planets Watch (IOPW) has extended its labours to the four Outer Planets. Here we present the Planetary Virtual Observatory & Laboratory (PVOL), a website database where we integer IJW and IOPW images. At PVOL observers can submit their data and professionals can search for images under a wide variety of useful criteria such as date and time, filters used, observer, or central meridian longitude. PVOL is aimed to grow as an organized easy to use database of amateur images of the Outer Planets. The PVOL web address is located at http://www.pvol.ehu.es/ and coexists with the traditional IOPW site: http://www.ehu.es/iopw/ Acknowledgements: This work has been funded by Spanish MCYT PNAYA2003-03216, fondos FEDER and Grupos UPV 15946/2004. R. Hueso acknowledges a post-doc fellowship from Gobierno Vasco.

Space Experiments with Particle Accelerators (SEPAC)

NASA Technical Reports Server (NTRS)

Taylor, William W. L.

1994-01-01

The scientific emphasis of this contract has been on the physics of beam ionosphere interactions, in particular, what are the plasma wave levels stimulated by the Space Experiments with Particle Accelerators (SEPAC) electron beam as it is ejected from the Electron Beam Accelerator (EBA) and passes into and through the ionosphere. There were two different phenomena expected. The first was generation of plasma waves by the interaction of the DC component of the beam with the plasma of the ionosphere, by wave particle interactions. The second was the generation of waves at the pulsing frequency of the beam (AC component). This is referred to as using the beam as a virtual antenna, because the beam of electrons is a coherent electrical current confined to move along the earth's magnetic field. As in a physical antenna, a conductor at a radio or TV station, the beam virtual antenna radiates electromagnetic waves at the frequency of the current variations. These two phenomena were investigated during the period of this contract.

Seismic Wave Propagation in South America,

DTIC Science & Technology

1995-08-14

Baby, P., B. Guiller, J . Oller , G. Herail, G. Montemurro D. 371 Zubietta and M. Specht (1993). Structural synthesis of the Bolivian Subandean zone...Bueno, E., A. Chirinos, J . Pinto and J . Moreno (1993). Structural interpretation of Ceuta Field, Lake Maracaibo, Venezuela. In Andean Geodynamics...on a lithospheric model. J . Geophys. Res. 98, 9825-9844. Drake, L.A. (1989). Love and Rayleigh waves in irregular structures. In Observatory

77 FR 25207 - Sunshine Act Meetings; National Science Board

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-27

... Gravity Wave Observatory (LIGO) Thursday, May 3, 2012 Committee on Strategy and Budget (CSB) Open Session... Election for NSB Chairman and Vice Chairman NSF Personnel Strategic Alignment of Budget and Functions...

Modeling Gravitational Radiation Waveforms from Black Hole Mergers

NASA Technical Reports Server (NTRS)

Baker, J. G.; Centrelia, J. M.; Choi, D.; Koppitz, M.; VanMeter, J.

2006-01-01

Gravitational radiation from merging binary black hole systems is anticipated as a key source for gravitational wave observations. Ground-based instruments, such as the Laser Interferometer Gravitational-wave Observatory (LIGO) may observe mergers of stellar-scale black holes, while the space-based Laser Interferometer Space Antenna (LISA) observatory will be sensitive to mergers of massive galactic-center black holes over a broad range of mass scales. These cataclysmic events may emit an enormous amount of energy in a brief time. Gravitational waves from comparable mass mergers carry away a few percent of the system's mass-energy in just a few wave cycles, with peak gravitational wave luminosities on the order of 10^23 L_Sun. Optimal analysis and interpretation of merger observation data will depend on developing a detailed understanding, based on general relativistic modeling, of the radiation waveforms. We discuss recent progress in modeling radiation from equal mass mergers using numerical simulations of Einstein's gravitational field equations, known as numerical relativity. Our simulations utilize Adaptive Mesh Refinement (AMR) to allow high-resolution near the black holes while simultaneously keeping the outer boundary of the computational domain far from the black holes, and making it possible to read out gravitational radiation waveforms in the weak-field wave zone. We discuss the results from simulations beginning with the black holes orbiting near the system's innermost stable orbit, comparing the recent simulations with earlier "Lazarus" waveform estimates based on an approximate hybrid numerical/perturbative technique.

Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results.

PubMed

Armano, M; Audley, H; Auger, G; Baird, J T; Bassan, M; Binetruy, P; Born, M; Bortoluzzi, D; Brandt, N; Caleno, M; Carbone, L; Cavalleri, A; Cesarini, A; Ciani, G; Congedo, G; Cruise, A M; Danzmann, K; de Deus Silva, M; De Rosa, R; Diaz-Aguiló, M; Di Fiore, L; Diepholz, I; Dixon, G; Dolesi, R; Dunbar, N; Ferraioli, L; Ferroni, V; Fichter, W; Fitzsimons, E D; Flatscher, R; Freschi, M; García Marín, A F; García Marirrodriga, C; Gerndt, R; Gesa, L; Gibert, F; Giardini, D; Giusteri, R; Guzmán, F; Grado, A; Grimani, C; Grynagier, A; Grzymisch, J; Harrison, I; Heinzel, G; Hewitson, M; Hollington, D; Hoyland, D; Hueller, M; Inchauspé, H; Jennrich, O; Jetzer, P; Johann, U; Johlander, B; Karnesis, N; Kaune, B; Korsakova, N; Killow, C J; Lobo, J A; Lloro, I; Liu, L; López-Zaragoza, J P; Maarschalkerweerd, R; Mance, D; Martín, V; Martin-Polo, L; Martino, J; Martin-Porqueras, F; Madden, S; Mateos, I; McNamara, P W; Mendes, J; Mendes, L; Monsky, A; Nicolodi, D; Nofrarias, M; Paczkowski, S; Perreur-Lloyd, M; Petiteau, A; Pivato, P; Plagnol, E; Prat, P; Ragnit, U; Raïs, B; Ramos-Castro, J; Reiche, J; Robertson, D I; Rozemeijer, H; Rivas, F; Russano, G; Sanjuán, J; Sarra, P; Schleicher, A; Shaul, D; Slutsky, J; Sopuerta, C F; Stanga, R; Steier, F; Sumner, T; Texier, D; Thorpe, J I; Trenkel, C; Tröbs, M; Tu, H B; Vetrugno, D; Vitale, S; Wand, V; Wanner, G; Ward, H; Warren, C; Wass, P J; Wealthy, D; Weber, W J; Wissel, L; Wittchen, A; Zambotti, A; Zanoni, C; Ziegler, T; Zweifel, P

2016-06-10

We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2±0.1  fm s^{-2}/sqrt[Hz], or (0.54±0.01)×10^{-15}  g/sqrt[Hz], with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8±0.3)  fm/sqrt[Hz], about 2 orders of magnitude better than requirements. At f≤0.5  mHz we observe a low-frequency tail that stays below 12  fm s^{-2}/sqrt[Hz] down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results

NASA Technical Reports Server (NTRS)

Armano, M.; Audley, H.; Auger, G.; Baird, J. T.; Bassan, M.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Thorpe, J. I.

2016-01-01

We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2 +/- 0.1 fm s(exp -2)/square root of Hz, or (0.54 +/- 0.01) x 10(exp -15) g/square root of Hz, with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8 +/- 0.3) fm square root of Hz, about 2 orders of magnitude better than requirements. At f less than or equal to 0.5 mHz we observe a low-frequency tail that stays below 12 fm s(exp -2)/square root of Hz down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

High Energy Astronomy Observatory (HEAO)

NASA Image and Video Library

1980-01-01

This x-ray photograph of the Supernova remnant Cassiopeia A, taken with the High Energy Astronomy Observatory (HEAO) 2/Einstein Observatory, shows that the regions with fast moving knots of material in the expanding shell are bright and clear. A faint x-ray halo, just outside the bright shell, is interpreted as a shock wave moving ahead of the expanding debris. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Services, Perspective and Directions of the Space Physics Data Facility

NASA Technical Reports Server (NTRS)

McGuire, Robert E.; Bilitza, Dieter; Candey, Reine A.; Chimiak, Reine A.; Cooper, John F.; Fung, Shing F.; Harris, Bernard T.; Johnson, Rita C.; King, Joseph H.; Kovalick, Tamara;

Characteristic changes in the physiological components of cybersickness.

PubMed

Kim, Young Youn; Kim, Hyun Ju; Kim, Eun Nam; Ko, Hee Dong; Kim, Hyun Taek

2005-09-01

We investigated the characteristic changes in the physiology of cybersickness when subjects were exposed to virtual reality. Sixty-one participants experienced a virtual navigation for a total of 9.5 min, and were required to detect specific virtual objects. Three questionnaires for sickness susceptibility and immersive tendency were obtained before the navigation. Sixteen electrophysiological signals were recorded before, during, and after the navigation. The severity of cybersickness experienced by participants was reported from a simulator sickness questionnaire after the navigation. The total severity of cybersickness had a significant positive correlation with gastric tachyarrhythmia, eyeblink rate, heart period, and EEG delta wave and a negative correlation with EEG beta wave. These results suggest that cybersickness accompanies the pattern changes in the activities of the central and the autonomic nervous systems.

Experimental study of an adaptive CFRC reflector for high order wave-front error correction

NASA Astrophysics Data System (ADS)

Lan, Lan; Fang, Houfei; Wu, Ke; Jiang, Shuidong; Zhou, Yang

2018-03-01

The recent radio frequency communication system developments are generating the need for creating space antennas with lightweight and high precision. The carbon fiber reinforced composite (CFRC) materials have been used to manufacture the high precision reflector. The wave-front errors caused by fabrication and on-orbit distortion are inevitable. The adaptive CFRC reflector has received much attention to do the wave-front error correction. Due to uneven stress distribution that is introduced by actuation force and fabrication, the high order wave-front errors such as print-through error is found on the reflector surface. However, the adaptive CFRC reflector with PZT actuators basically has no control authority over the high order wave-front errors. A new design architecture assembled secondary ribs at the weak triangular surfaces is presented in this paper. The virtual experimental study of the new adaptive CFRC reflector has conducted. The controllability of the original adaptive CFRC reflector and the new adaptive CFRC reflector with secondary ribs are investigated. The virtual experimental investigation shows that the new adaptive CFRC reflector is feasible and efficient to diminish the high order wave-front error.

Exploring remote operation for ALMA Observatory

NASA Astrophysics Data System (ADS)

Shen, Tzu-Chiang; Soto, Ruben; Ovando, Nicolás.; Velez, Gaston; Fuica, Soledad; Schemrl, Anton; Robles, Andres; Ibsen, Jorge; Filippi, Giorgio; Pietriga, Emmanuel

2014-08-01

The Atacama Large Millimeter /submillimeter Array (ALMA) will be a unique research instrument composed of at least 66 reconfigurable high-precision antennas, located at the Chajnantor plain in the Chilean Andes at an elevation of 5000 m. The observatory has another office located in Santiago of Chile, 1600 km from the Chajnantor plain. In the Atacama desert, the wonderful observing conditions imply precarious living conditions and extremely high operation costs: i.e: flight tickets, hospitality, infrastructure, water, electricity, etc. It is clear that a purely remote operational model is impossible, but we believe that a mixture of remote and local operation scheme would be beneficial to the observatory, not only in reducing the cost but also in increasing the observatory overall efficiency. This paper describes the challenges and experience gained in such experimental proof of the concept. The experiment was performed over the existing 100 Mbps bandwidth, which connects both sites through a third party telecommunication infrastructure. During the experiment, all of the existent capacities of the observing software were validated successfully, although room for improvement was clearly detected. Network virtualization, MPLS configuration, L2TPv3 tunneling, NFS adjustment, operational workstations design are part of the experiment.

Recent Ultra High Energy neutrino bounds and multimessenger observations with the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Zas, Enrique

2018-01-01

The overall picture of the highest energy particles produced in the Universe is changing because of measurements made with the Pierre Auger Observatory. Composition studies of cosmic rays point towards an unexpected mixed composition of intermediate mass nuclei, more isotropic than anticipated, which is reshaping the future of the field and underlining the priority to understand composition at the highest energies. The Observatory is competitive in the search for neutrinos of all flavors above about 100 PeV by looking for very inclined showers produced deep in the atmosphere by neutrinos interacting either in the atmosphere or in the Earth's crust. It covers a large field of view between -85° and 60° declination in equatorial coordinates. Neutrinos are expected because of the existence of ultra high energy cosmic rays. They provide valuable complementary information, their fluxes being sensitive to the primary cosmic ray masses and their directions reflecting the source positions. We report the results of the neutrino search providing competitive bounds to neutrino production and strong constraints to a number of production models including cosmogenic neutrinos due to ultra high energy protons. We also report on two recent contributions of the Observatory to multimessenger studies by searching for correlations of neutrinos both with cosmic rays and with gravitational waves. The correlations of the directions of the highest energy astrophysical neutrinos discovered with IceCube with the highest energy cosmic rays detected with the Auger Observatory and the Telescope Array revealed an excess that is not statistically significant and is being monitored. The targeted search for neutrinos correlated with the discovery of the gravitational wave events GW150914 and GW151226 with advanced LIGO has led to the first bounds on the energy emitted by black hole mergers in Ultra-High Energy Neutrinos.

Overview of the Chandra X-Ray Observatory Facility

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; Six, N. Frank (Technical Monitor)

2002-01-01

The Chandra X-Ray Observatory (originally called the Advanced X-Ray Astrophysics Facility - AXAF) is the X-Ray component of NASA's "Great Observatory" Program. Chandra is a NASA facility that provides scientific data to the international astronomical community in response to scientific proposals for its use. The Observatory is the product of the efforts of many organizations in the United States and Europe. The Great Observatories also include the Hubble Space Telescope for space-based observations of astronomical objects primarily in the visible portion of the electromagnetic spectrum, the now defunct Compton Gamma- Ray Observatory that was designed to observe gamma-ray emission from astronomical objects, and the soon-to-be-launched Space Infrared Telescope Facility (SIRTF). The Chandra X-Ray Observatory (hereafter CXO) is sensitive to X-rays in the energy range from below 0.1 to above 10.0 keV corresponding to wavelengths from 12 to 0.12 nanometers. The relationship among the various parts of the electromagnetic spectrum, sorted by characteristic temperature and the corresponding wavelength, is illustrated. The German physicist Wilhelm Roentgen discovered what he thought was a new form of radiation in 1895. He called it X-radiation to summarize its properties. The radiation had the ability to pass through many materials that easily absorb visible light and to free electrons from atoms. We now know that X-rays are nothing more than light (electromagnetic radiation) but at high energies. Light has been given many names: radio waves, microwaves, infrared, visible, ultraviolet, X-ray and gamma radiation are all different forms. Radio waves are composed of low energy particles of light (photons). Optical photons - the only photons perceived by the human eye - are a million times more energetic than the typical radio photon, whereas the energies of X-ray photons range from hundreds to thousands of times higher than that of optical photons. Very low temperature systems (hundreds of degrees below zero Celsius) produce low energy radio and microwave photons, whereas cool bodies like our own (about 30 degrees Celsius) produce infrared radiation. Very high temperatures (millions of degrees Celsius) are one way of producing X-rays.

Footprint Database and web services for the Herschel space observatory

NASA Astrophysics Data System (ADS)

Verebélyi, Erika; Dobos, László; Kiss, Csaba

2015-08-01

Using all telemetry and observational meta-data, we created a searchable database of Herschel observation footprints. Data from the Herschel space observatory is freely available for everyone but no uniformly processed catalog of all observations has been published yet. As a first step, we unified the data model for all three Herschel instruments in all observation modes and compiled a database of sky coverage information. As opposed to methods using a pixellation of the sphere, in our database, sky coverage is stored in exact geometric form allowing for precise area calculations. Indexing of the footprints allows for very fast search among observations based on pointing, time, sky coverage overlap and meta-data. This enables us, for example, to find moving objects easily in Herschel fields. The database is accessible via a web site and also as a set of REST web service functions which makes it usable from program clients like Python or IDL scripts. Data is available in various formats including Virtual Observatory standards.

Added value of Virtual Touch IQ shear wave elastography in the ultrasound assessment of breast lesions.

PubMed

Ianculescu, Victor; Ciolovan, Laura Maria; Dunant, Ariane; Vielh, Philippe; Mazouni, Chafika; Delaloge, Suzette; Dromain, Clarisse; Blidaru, Alexandru; Balleyguier, Corinne

2014-05-01

To determine the diagnostic performance of Acoustic Radiation Force Impulse (ARFI) Virtual Touch IQ shear wave elastography in the discrimination of benign and malignant breast lesions. Conventional B-mode and elasticity imaging were used to evaluate 110 breast lesions. Elastographic assessment of breast tissue abnormalities was done using a shear wave based technique, Virtual Touch IQ (VTIQ), implemented on a Siemens Acuson S3000 ultrasound machine. Tissue mechanical properties were interpreted as two-dimensional qualitative and quantitative colour maps displaying relative shear wave velocity. Wave speed measurements in m/s were possible at operator defined regions of interest. The pathologic diagnosis was established on samples obtained by ultrasound guided core biopsy or fine needle aspiration. BIRADS based B-mode evaluation of the 48 benign and 62 malignant lesions achieved 92% sensitivity and 62.5% specificity. Subsequently performed VTIQ elastography relying on visual interpretation of the colour overlay displaying relative shear wave velocities managed similar standalone diagnostic performance with 92% sensitivity and 64.6% specificity. Lesion and surrounding tissue shear wave speed values were calculated and a significant difference was found between the benign and malignant populations (Mann-Whitney U test, p<0.0001). By selecting a lesion cut-off value of 3.31m/s we achieved 80.4% sensitivity and 73% specificity. Applying this threshold only to BIRADS 4a masses, we reached overall levels of 92% sensitivity and 72.9% specificity. VTIQ qualitative and quantitative elastography has the potential to further characterise B-mode detected breast lesions, increasing specificity and reducing the number of unnecessary biopsies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

High lateral resolution exploration using surface waves from noise records

NASA Astrophysics Data System (ADS)

Chávez-García, Francisco José Yokoi, Toshiaki

2016-04-01

Determination of the shear-wave velocity structure at shallow depths is a constant necessity in engineering or environmental projects. Given the sensitivity of Rayleigh waves to shear-wave velocity, subsoil structure exploration using surface waves is frequently used. Methods such as the spectral analysis of surface waves (SASW) or multi-channel analysis of surface waves (MASW) determine phase velocity dispersion from surface waves generated by an active source recorded on a line of geophones. Using MASW, it is important that the receiver array be as long as possible to increase the precision at low frequencies. However, this implies that possible lateral variations are discarded. Hayashi and Suzuki (2004) proposed a different way of stacking shot gathers to increase lateral resolution. They combined strategies used in MASW with the common mid-point (CMP) summation currently used in reflection seismology. In their common mid-point with cross-correlation method (CMPCC), they cross-correlate traces sharing CMP locations before determining phase velocity dispersion. Another recent approach to subsoil structure exploration is based on seismic interferometry. It has been shown that cross-correlation of a diffuse field, such as seismic noise, allows the estimation of the Green's Function between two receivers. Thus, a virtual-source seismic section may be constructed from the cross-correlation of seismic noise records obtained in a line of receivers. In this paper, we use the seismic interferometry method to process seismic noise records obtained in seismic refraction lines of 24 geophones, and analyse the results using CMPCC to increase the lateral resolution of the results. Cross-correlation of the noise records allows reconstructing seismic sections with virtual sources at each receiver location. The Rayleigh wave component of the Green's Functions is obtained with a high signal-to-noise ratio. Using CMPCC analysis of the virtual-source seismic lines, we are able to identify lateral variations of phase velocity inside the seismic line, and increase the lateral resolution compared with results of conventional analysis.

Detection regimes of the cosmological gravitational wave background from astrophysical sources

NASA Astrophysics Data System (ADS)

Coward, David; Regimbau, Tania

2006-09-01

Key targets for gravitational wave (GW) observatories, such as LIGO and the next generation interferometric detector, Advanced LIGO, include core-collapse of massive stars and the final stage of coalescence of compact stellar remnants. The combined GW signal from such events occurring throughout the Universe will produce an astrophysical GW background (AGB), one that is fundamentally different from the GW background by very early Universe processes. One can classify contributions to the AGB for different classes of sources based on the strength of the GW emissions from the individual sources, their peak emission frequency, emission duration and their event rate density distribution. This article provides an overview of the detectability regimes of the AGB in the context of current and planned gravitational wave observatories. We show that there are two important AGB signal detection regimes, which we define as 'continuous' and 'popcorn noise'. We describe how the 'popcorn noise' AGB regime evolves with observation time and we discuss how this feature distinguishes it from the GW background produced from very early Universe processes.

Alfvén Wave Heating Model of an Active Region and Comparisons with the EIS Observations

NASA Astrophysics Data System (ADS)

Lawless, A. P.; Asgari-Targhi, M.

2013-12-01

We study the generation and dissipation of Alfvén waves in open and closed field lines using the images from the Solar Dynamics Observatory's (SDO) Atmospheric Imaging Assembly (AIA) (van Ballegouijen et al. 2011; Asgari-Targhi & van Ballegouijen 2012; Asgari et al. 2013). The goal is to search for observational evidence of Alfvén waves in the solar corona and to understand their role in coronal heating. We focus on one particular active region on the 10th of December 2007. Using the MDI magnetogram and the potential field modeling of this region, we create three-dimensional MHD models for several open and closed field lines in different locations in the active region. For each model, we compute the temperature, pressure, magnetic field strength, average heating rate, and other parameters along the loop. We then compare these results with the EIS observations. This research is supported by the NSF grant for the Solar physics REU Program at the Smithsonian Astrophysical Observatory (AGS-1263241) and contract SP02H1701R from Lockheed-Martin to SAO.

A database of virtual healthy subjects to assess the accuracy of foot-to-foot pulse wave velocities for estimation of aortic stiffness.

PubMed

Willemet, Marie; Chowienczyk, Phil; Alastruey, Jordi

2015-08-15

While central (carotid-femoral) foot-to-foot pulse wave velocity (PWV) is considered to be the gold standard for the estimation of aortic arterial stiffness, peripheral foot-to-foot PWV (brachial-ankle, femoral-ankle, and carotid-radial) are being studied as substitutes of this central measurement. We present a novel methodology to assess theoretically these computed indexes and the hemodynamics mechanisms relating them. We created a database of 3,325 virtual healthy adult subjects using a validated one-dimensional model of the arterial hemodynamics, with cardiac and arterial parameters varied within physiological healthy ranges. For each virtual subject, foot-to-foot PWV was computed from numerical pressure waveforms at the same locations where clinical measurements are commonly taken. Our numerical results confirm clinical observations: 1) carotid-femoral PWV is a good indicator of aortic stiffness and correlates well with aortic PWV; 2) brachial-ankle PWV overestimates aortic PWV and is related to the stiffness and geometry of both elastic and muscular arteries; and 3) muscular PWV (carotid-radial, femoral-ankle) does not capture the stiffening of the aorta and should therefore not be used as a surrogate for aortic stiffness. In addition, our analysis highlights that the foot-to-foot PWV algorithm is sensitive to the presence of reflected waves in late diastole, which introduce errors in the PWV estimates. In this study, we have created a database of virtual healthy subjects, which can be used to assess theoretically the efficiency of physiological indexes based on pulse wave analysis. Copyright © 2015 the American Physiological Society.

A database of virtual healthy subjects to assess the accuracy of foot-to-foot pulse wave velocities for estimation of aortic stiffness

PubMed Central

Chowienczyk, Phil; Alastruey, Jordi

2015-01-01

While central (carotid-femoral) foot-to-foot pulse wave velocity (PWV) is considered to be the gold standard for the estimation of aortic arterial stiffness, peripheral foot-to-foot PWV (brachial-ankle, femoral-ankle, and carotid-radial) are being studied as substitutes of this central measurement. We present a novel methodology to assess theoretically these computed indexes and the hemodynamics mechanisms relating them. We created a database of 3,325 virtual healthy adult subjects using a validated one-dimensional model of the arterial hemodynamics, with cardiac and arterial parameters varied within physiological healthy ranges. For each virtual subject, foot-to-foot PWV was computed from numerical pressure waveforms at the same locations where clinical measurements are commonly taken. Our numerical results confirm clinical observations: 1) carotid-femoral PWV is a good indicator of aortic stiffness and correlates well with aortic PWV; 2) brachial-ankle PWV overestimates aortic PWV and is related to the stiffness and geometry of both elastic and muscular arteries; and 3) muscular PWV (carotid-radial, femoral-ankle) does not capture the stiffening of the aorta and should therefore not be used as a surrogate for aortic stiffness. In addition, our analysis highlights that the foot-to-foot PWV algorithm is sensitive to the presence of reflected waves in late diastole, which introduce errors in the PWV estimates. In this study, we have created a database of virtual healthy subjects, which can be used to assess theoretically the efficiency of physiological indexes based on pulse wave analysis. PMID:26055792

Modeling rapidly spinning, merging black holes with numerical relativity for the era of first gravitational-wave observations

NASA Astrophysics Data System (ADS)

Lovelace, Geoffrey; Simulating eXtreme Collaboration; LIGO Scientific Collaboration

2016-03-01

The Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) began searching for gravitational waves in September 2015, with three times the sensitivity of the initial LIGO experiment. Merging black holes are among the most promising sources of gravitational waves for Advanced LIGO, but near the time of merger, the emitted waves can only be computed using numerical relativity. In this talk, I will present new numerical-relativity simulations of merging black holes, made using the Spectral Einstein Code [black-holes.org/SpEC.html], including cases with black-hole spins that are nearly as fast as possible. I will discuss how such simulations will be able to rapidly follow up gravitational-wave observations, improving our understanding of the waves' sources.

Signatures of Nonlinear Waves in Coronal Plumes and Holes

NASA Technical Reports Server (NTRS)

Ofman, Leon

1999-01-01

In recent Ultraviolet Coronagraph Spectrometer/Solar and Heliospheric Observatory (UVCS/SOHO) White Light Channel (WLC) observations we found quasi-periodic variations in the polarized brightness (pB) in the polar coronal holes at heliocentric distances of 1.9-2.45 solar radii. The motivation for the observation is the 2.5D Magnetohydrodynamics (MHD) model of solar wind acceleration by nonlinear waves, that predicts compressive fluctuations in coronal holes. To help identify the waves observed with the UVCS/WLC we model the propagation and dissipation of slow magnetosonic waves in polar plumes using 1D MHD code in spherical geometry, We find that the slow waves nonlinearly steepen in the gravitationally stratified plumes. The nonlinear steepening of the waves leads to enhanced dissipation due to compressive viscosity at the wave-fronts.

The VTIE telescope resource management system

NASA Astrophysics Data System (ADS)

Busschots, B.; Keating, J. G.

2005-06-01

The VTIE Telescope Resource Management System (TRMS) provides a frame work for managing a distributed group of internet telescopes as a single "Virtual Observatory". The TRMS provides hooks which allow for it to be connected to any Java Based web portal and for a Java based scheduler to be added to it. The TRMS represents each telescope and observatory in the system with a software agent and then allows the scheduler and web portal to communicate with these distributed resources in a simple transparent way, hence allowing the scheduler and portal designers to concentrate only on what they wish to do with these resources rather than how to communicate with them. This paper outlines the structure and implementation of this frame work.

Autonomous Infrastructure for Observatory Operations

NASA Astrophysics Data System (ADS)

Seaman, R.

This is an era of rapid change from ancient human-mediated modes of astronomical practice to a vision of ever larger time domain surveys, ever bigger "big data", to increasing numbers of robotic telescopes and astronomical automation on every mountaintop. Over the past decades, facets of a new autonomous astronomical toolkit have been prototyped and deployed in support of numerous space missions. Remote and queue observing modes have gained significant market share on the ground. Archives and data-mining are becoming ubiquitous; astroinformatic techniques and virtual observatory standards and protocols are areas of active development. Astronomers and engineers, planetary and solar scientists, and researchers from communities as diverse as particle physics and exobiology are collaborating on a vast range of "multi-messenger" science. What then is missing?

ESONET , a milestone towards sustained multidisciplinary ocean observation.

NASA Astrophysics Data System (ADS)

Rolin, J.-F.

2012-04-01

At the end of a 4 year project dedicated to the constitution of a Network of Excellence (NoE) on subsea observatories in Europe, large expectations are still in the agenda. The economical crisis changes the infrastructure construction planning in many ways but the objectives are quite clear and may be reached at European scale. The overall objective of the ESONET NoE was to create an organisation able to implement, operate and maintain a sustainable underwater observation network, extending into deep water, capable of monitoring biological, geo-chemical, geological, geophysical and physical processes occurring throughout the water column, sea floor interface and solid earth below. This main objective of ESONET has been met by creating the network of 11 permanent underwater observation sites together with the "ESONET Vi" Virtual Institute organising the exchange of staff and joint experiments on EMSO large research infrastructure observatories. The development of recommendations on best practices, standardization and interoperability concepts concerning underwater observatory equipment, as synthetized by the so called ESONET Label document has been created. The ESONET Label is a set of criteria to be met by the deep-sea observatory equipment as well as recommended solutions and options to guarantee their optimal operation in the ocean over long time periods. ESONET contributes to the fixed point sustained observatory community which extends worldwide, is fully multidisciplinary and in its way may open a new page in ocean sciences history.

The Hunt for a Counterpart to GW150914

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-07-01

On 14 September 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) in a pre-operative testing state at the time detected its first sign of gravitational-waves. The LIGO team sprang into action, performing data-quality checks on this unexpected signal. Within two days, they had sent a notification to 63 observing teams at observatories representing the entire electromagnetic spectrum, from radio to gamma-ray wavelengths.Illustration of a binary neutron star merger. The neutron stars 1) inspiral, 2) can produce a short gamma-ray burst, 3) can fling out hot, radioactive material in the form of a kilonova, and 4) form a massive neutron star or black hole with a possible remnant debris disk around it. [NASA/ESA/A. Feild (STScI)]Thus began the very first hunt for an electromagnetic counterpart to a detected gravitational wave signal.What were they looking for?As two compact objects in a binary system merge, the system is expected to emit energy in the form of gravitational waves. If both of the compact objects are black holes, were unlikely to see any electromagnetic radiation in the process, unless the merger is occurring in an (improbable) environment filled with gas and dust.But if one or both of the two compact objects is a neutron star, then there are a number of electromagnetic signatures that could occur due to energetic outflows. If a relativistic jet forms, we could see a short gamma-ray burst and X-ray, optical, and radio afterglows. Sub-relativistic outflows could produce optical and near-infrared signals, or a radio blast wave.Timeline of observations of GW150914, separated by wavelength band, and relative to the time of the gravitational-wave trigger. The top row shows LIGO information releases. The bottom four rows show high-energy, optical, near-infrared, and radio observations, respectively. Click for a closer look! [Abbott et al. 2016]Surprise SignalSince LIGO and Virgo (LIGOs European counterpart), wereprimarily expecting to detect binaries involving neutron stars, they set up a notification system to be able to quickly alert electromagnetic observatories of a gravitational-wave detection. Those observatories would then be able to follow up on the gravitational-wave detectorsrough localization, with the goal of detecting the source by its electromagnetic signature.Given that LIGO had only just come online for testing when GW150914 was detected, its impressive that the pipeline was ready and there were observatories able to follow up so quickly! When the alert went out, 25 teams responded, mobilizing satellites and ground-based telescopes spanning 19 orders of magnitude in electromagnetic wavelength.The Search PartyThe only information the teams were initially given was the localization of the signal to roughly 600 square degrees on the sky. With this starting point, over the next three months, these 25 facilities carefully observed the entirety of the estimated localization area.Footprints of observations in comparison with the initial LIGO localization of GW150914 (black contours). Shown are radio fields (red), optical/infrared fields (green), and X-ray fields (blue circles); not shown are the all-sky Fermi GBM, LAT, INTEGRAL SPI-ACS, and MAXI observations. [Abbott et al. 2016]Some high-energy observatories, like Fermi and INTEGRAL, covered the whole sky. Many optical facilities used a tiling strategy, together covering about 900 square degrees. Still other observatories used a targeted approach, specifically looking at fields that contained a high density of nearby galaxies, in the hopes of detecting signs of a neutron-star merger or a core-collapse supernova.For the transient sources that were found, follow-up spectroscopy and further photometry was performed, to determine if the transient could have been the source of the detected gravitational waves.What Was the Outcome?No electromagnetic counterpart to GW150914 was found. It turns out this isnt surprising; GW150914 was later determined to have been the merger of two black holes, which should not generate an electromagnetic signature.So why report on this? In the publication prepared jointly by LIGO, Virgo, and these 25 teams (with one of the longer author lists youre likely to encounter!), the authors emphasize not the conclusion, but the process leading to it.In spite of the fact that LIGO had not yet even begun its first observing run, the alert system worked, and the community mobilized to cover the entire 600 square degrees of sky with observations and follow-up characterization of candidate sources. If all this can be accomplished for an unexpected signal, imagine how well the system will work for future detections during actual science runs! With any luck, well be identifying the electromagnetic counterparts to gravitational-wave sources soon.CitationB. P. Abbott et al 2016 ApJ 826 L13. doi:10.3847/2041-8205/826/1/L13

Surface ozone variability at Kislovodsk Observatory

NASA Technical Reports Server (NTRS)

Elansky, Nikolay F.; Makarov, Oleg V.; Senik, Irina A.

1994-01-01

The results of the surface ozone observations at the Observatory 'Kislovodsk', situated in the North Caucasus at the altitude 2070 m a.s.l., are given. The observatory is in the background conditions and the variations of the surface ozone are determined by the natural dynamic and photochemical processes. The mean value of the concentration and its seasonal variations are very near to those obtained at the high-mountain stations in Alps. The daily variations have the features, which remain stable during all warm period of the year (April-October). These features, including the minimum of the surface ozone at noon, are formed by the mountain-valley circulation. The significant variations of the surface ozone are connected with the unstationary lee waves.

CSU's MWV Observatory: A Facility for Research, Education and Outreach

NASA Astrophysics Data System (ADS)

Hood, John; Carpenter, N. D.; McCarty, C. B.; Samford, J. H.; Johnson, M.; Puckett, A. W.; Williams, R. N.; Cruzen, S. T.

2014-01-01

The Mead Westvaco Observatory (MWVO), located in Columbus State University's Coca-Cola Space Science Center, is dedicated to education and research in astronomy through hands-on engagement and public participation. The MWVO has recently received funding to upgrade from a 16-inch Meade LX-200 telescope to a PlaneWave CDK 24-inch Corrected Dall-Kirkham Astrograph telescope. This and other technological upgrades will allow this observatory to stream live webcasts for astronomical events, allowing a worldwide public audience to become a part of the growing astronomical community. This poster will explain the upgrades that are currently in progress as well as the results from the current calibrations. The goal of these upgrades is to provide facilities capable of both research-class projects and widespread use in education and public outreach. We will present our initial calibration and tests of the observatory equipment, as well as its use in webcasts of astronomical events, in solar observing through the use of specialized piggy-backed telescopes, and in research into such topics as asteroids, planetary and nebula imaging. We will describe a pilot research project on asteroid orbit refinement and light curves, to be carried out by Columbus State University students. We will also outline many of the K-12 educational and public outreach activities we have designed for these facilities. Support and funding for the acquisition and installation of the new PlaneWave CDK 24 has been provided by the International Museum and Library Services via the Museums for America Award.

The Etelman Observatory and the Virgin Islands Robotic Telescope: 2017 Milestone Achievements and Determined Resilience in the USVI

NASA Astrophysics Data System (ADS)

Morris, David C.; Gendre, Bruce; Orange, N. Brice; Cucchiara, Antonino; Giblin, Timothy W.; Klotz, Alain; Thierry, Pierre

2018-01-01

The Virgin Islands Robotic Telescope (VIRT) is an 0.5m robotic telescope located at the easternmost and southernmost optical observatory in the United States at a latitude of 18.5N and longitude of 65W. The observatory is located on the island of St Thomas in the United States Virgin Islands (USVI). Astronomers from the College of Charleston, the US Air Force Academy and the University of the Virgin Islands (UVI) collaborate to maintain and operate the facility. Science goals of the facility include optical follow-up of high-energy transients, extra-solar planet observations, and near-Earth asteroid searches. The facility also supports a wide-reaching education and outreach program dedicated to raising the level of STEM engagement and enrichment in the USVI and is a primary research facility for students in UVI's new Physics Degree with a Concentration in Astronomy. The VIRT has begun reacting autonomously to the gamma-ray coordinates network (GCN) alerts in 2017 and, despite the challenges presented to the Caribbean region by hurricanes Irma and Maria, was a participant in the follow-up campaign of GW170817, the first source simultaneously detected in gravitational waves and electromagnetic waves. We detail the robotization and automation of the VIRT, provide an update on its characteristics and capabilities and discuss recent science results from the observatory as well as ongoing progress in the recovery from damage caused by hurricanes Irma and Maria.

Discriminating different type waves from pressure and ground motion observation in the seafloor by DONET cabled observation network.

NASA Astrophysics Data System (ADS)

Araki, E.; Kawaguchi, K.; Kaneda, Y.

2011-12-01

We developed and deployed seafloor cabled observatory called "Dense Ocean-floor Network for Earthquake and Tsunamis (DONET)" in the Nankai Trough, south of Japan. The main purpose of the DONET network is to observe large earthquake such as Tonankai earthquake in the deployed seafloor and associate Tsunamis in real-time to help disaster mitigation, and as well to monitor inter-seismic crustal activities such as micro earthquakes, very low frequency earthquakes, and slower crustal deformation. In each DONET seafloor observatory, high-sensitive broadband set of instruments for seismic and seafloor pressure monitoring, consisted from Guralp CMG3T broadband seismometer, Metrozet TSA100S accelerometer, Paroscientific 8B7000-2 pressure gauge, a deep-sea differential pressure gauge, a hydrophone, and a seawater thermometer, are installed. The density of seafloor observatories are 20 observatories distributed in 15-30 km interval which is optimized for monitoring of events in the plate boundary beneath the network. DONET may be regarded as a large-scale, high sensitive high density seismic array for monitoring teleseismic events in the Philippine Sea and the Pacific Ocean. The DONET seafloor observatories are situated in wide range of seafloor depth between 1800m and 4500m, from the seafloor basin about 50 km off Japanese Island through the slope of accerecionary prism to the deep trench axis 150 km off the coast, that may also regarded as a vertical array in the 4.5km thick ocean. This variation of depths helps identify T-phases from the array record. In data analysis, it is necessary to identify propagation mode of each observed wave which may often be mixed together. In our design of DONET observation system, we took care to help identification of seismic phase by obtaining both ground motion and seafloor pressure in the same location. This is simply achieved by combining seafloor pressure gauges and seismometer in a single observatory package, but care was taken to observe both in the similar level of sensitivity and dynamic range in wide frequencies from near DC to over 100 Hz. In the case of DONET, the broadband seismometer and the differential pressure gauge have similar level of sensitivity in 0.005 - 10 Hz, and similarly the accelerometer and the hydrophone cover between 1-100Hz, in total covering most frequencies of our interest, 0.005 Hz to 100 Hz. With both ground motion and seafloor pressure measurement, we may distinguish types of waves relatively easily, and it is also possible to filter particular types of waves from the array dataset to help our data analysis. For example, it has been commonly practiced to distinguish up-going and down-going seismic phases from pressure and ground motion, but this is relatively difficult only with sparse seismometer array. This technique may also be applied to correct teleseismic record with sea surface reflection in receiver function analysis for exploring deep crustal structure.

History of Chandra X-Ray Observatory

NASA Image and Video Library

2000-11-01

This image is a color composite of the supernova remnant E0102-72: x-ray (blue), optical (green), and radio (red). E0102-72 is the remnant of a star that exploded in a nearby galaxy known as the Small Magellanic Cloud. The star exploded outward at speeds in excess of 20 million kilometers per hour (12 million mph) and collided with surrounding gas. This collision produced two shock waves, or cosmic sonic booms, one traveling outward, and the other rebounding back into the material ejected by the explosion. The radio image, shown in red, was made using the Australia Telescope Compact Array. The radio waves are due to extremely high-energy electrons spiraling around magnetic field lines in the gas and trace the outward moving shock wave. The Chandra X-ray Observatory image, shown in blue, shows gas that has been heated to millions of degrees by the rebounding, or reverse shock wave. The x-ray data show that this gas is rich in oxygen and neon. These elements were created by nuclear reactions inside the star and hurled into space by the supernova. The Hubble Space Telescope optical image, shown in green, shows dense clumps of oxygen gas that have "cooled" to about 30,000 degrees. Photo Credit: X-ray (NASA/CXC/SAO); optical (NASA/HST): radio: (ACTA)

Indexing data cubes for content-based searches in radio astronomy

NASA Astrophysics Data System (ADS)

Araya, M.; Candia, G.; Gregorio, R.; Mendoza, M.; Solar, M.

2016-01-01

Methods for observing space have changed profoundly in the past few decades. The methods needed to detect and record astronomical objects have shifted from conventional observations in the optical range to more sophisticated methods which permit the detection of not only the shape of an object but also the velocity and frequency of emissions in the millimeter-scale wavelength range and the chemical substances from which they originate. The consolidation of radio astronomy through a range of global-scale projects such as the Very Long Baseline Array (VLBA) and the Atacama Large Millimeter/submillimeter Array (ALMA) reinforces the need to develop better methods of data processing that can automatically detect regions of interest (ROIs) within data cubes (position-position-velocity), index them and facilitate subsequent searches via methods based on queries using spatial coordinates and/or velocity ranges. In this article, we present the development of an automatic system for indexing ROIs in data cubes that is capable of automatically detecting and recording ROIs while reducing the necessary storage space. The system is able to process data cubes containing megabytes of data in fractions of a second without human supervision, thus allowing it to be incorporated into a production line for displaying objects in a virtual observatory. We conducted a set of comprehensive experiments to illustrate how our system works. As a result, an index of 3% of the input size was stored in a spatial database, representing a compression ratio equal to 33:1 over an input of 20.875 GB, achieving an index of 773 MB approximately. On the other hand, a single query can be evaluated over our system in a fraction of second, showing that the indexing step works as a shock-absorber of the computational time involved in data cube processing. The system forms part of the Chilean Virtual Observatory (ChiVO), an initiative which belongs to the International Virtual Observatory Alliance (IVOA) that seeks to provide the capability of content-based searches on data cubes to the astronomical community.

The Virtual Observatory Service TheoSSA: Establishing a Database of Synthetic Stellar Flux Standards I. NLTE Spectral Analysis of the DA-Type White Dwarf G191-B2B *,**,***,****

NASA Technical Reports Server (NTRS)

Rauch, T.; Werner, K.; Bohlin, R.; Kruk, J. W.

2013-01-01

Hydrogen-rich, DA-type white dwarfs are particularly suited as primary standard stars for flux calibration. State-of-the-art NLTE models consider opacities of species up to trans-iron elements and provide reliable synthetic stellar-atmosphere spectra to compare with observations. Aims. We will establish a database of theoretical spectra of stellar flux standards that are easily accessible via a web interface. Methods. In the framework of the Virtual Observatory, the German Astrophysical Virtual Observatory developed the registered service TheoSSA. It provides easy access to stellar spectral energy distributions (SEDs) and is intended to ingest SEDs calculated by any model-atmosphere code. In case of the DA white dwarf G191-B2B, we demonstrate that the model reproduces not only its overall continuum shape but also the numerous metal lines exhibited in its ultraviolet spectrum. Results. TheoSSA is in operation and contains presently a variety of SEDs for DA-type white dwarfs. It will be extended in the near future and can host SEDs of all primary and secondary flux standards. The spectral analysis of G191-B2B has shown that our hydrostatic models reproduce the observations best at Teff =60 000 +/- 2000K and log g=7.60 +/- 0.05.We newly identified Fe vi, Ni vi, and Zn iv lines. For the first time, we determined the photospheric zinc abundance with a logarithmic mass fraction of -4.89 (7.5 × solar). The abundances of He (upper limit), C, N, O, Al, Si, O, P, S, Fe, Ni, Ge, and Sn were precisely determined. Upper abundance limits of about 10% solar were derived for Ti, Cr, Mn, and Co. Conclusions. The TheoSSA database of theoretical SEDs of stellar flux standards guarantees that the flux calibration of all astronomical data and cross-calibration between different instruments can be based on the same models and SEDs calculated with different model-atmosphere codes and are easy to compare.

The First Unambiguous Electromagnetic Counterpart to a Gravitational-Wave Signal: GRB 170817A and GW170817

NASA Astrophysics Data System (ADS)

Goldstein, Adam

2018-01-01

On 2017 August 17 at 12:41:06 UTC the Fermi Gamma-ray Burst Monitor (GBM) detected and triggered on the short gamma-ray burst (GRB) 170817A. Approximately 2 s prior to this GRB, the LIGO gravitational-wave observatory triggered on a binary compact merger candidate associated with the GRB. This is the first unambiguous coincident observation of gravitational waves and electromagnetic radiation from a single astrophysical source and marks the start of gravitational-wave multi-messenger astronomy. We report the GBM observations and analysis of this short GRB and the joint science that results from this discovery.

Detecting high-frequency gravitational waves with optically levitated sensors.

PubMed

Arvanitaki, Asimina; Geraci, Andrew A

2013-02-15

We propose a tunable resonant sensor to detect gravitational waves in the frequency range of 50-300 kHz using optically trapped and cooled dielectric microspheres or microdisks. The technique we describe can exceed the sensitivity of laser-based gravitational wave observatories in this frequency range, using an instrument of only a few percent of their size. Such a device extends the search volume for gravitational wave sources above 100 kHz by 1 to 3 orders of magnitude, and could detect monochromatic gravitational radiation from the annihilation of QCD axions in the cloud they form around stellar mass black holes within our galaxy due to the superradiance effect.

Mechanisms of myocardial capture and temporal excitable gap during spiral wave reentry in a bidomain model.

PubMed

Ashihara, Takashi; Namba, Tsunetoyo; Ikeda, Takanori; Ito, Makoto; Nakazawa, Kazuo; Trayanova, Natalia

2004-02-24

Recent studies have demonstrated that regional capture during cardiac fibrillation is associated with an elevated capture threshold. It is typically assumed that the temporal excitable gap (capture window) during fibrillation reflects the size of the spatial excitable gap (excitable tissue between fibrillation waves). Because capture threshold is high, virtual electrode polarization is expected to be involved in the process. However, little is known about the underlying mechanisms of myocardial capture during fibrillation. To clarify these issues, we conducted altogether 3168 simulations of single spiral wave capture in a bidomain sheet. Unipolar stimuli of strengths 4, 8, 16, and 24 mA and 2-ms duration were delivered at 99 locations in the sheet. We found that cathode-break rather than cathode-make excitation was the dominant mechanism of myocardial capture. When the stimulation site was located diagonally with respect to the core (upper left or lower right if the spiral wave rotates counterclockwise), the cathode-break excitation easily invaded the spatial excitable gap and resulted in a successful capture as a result of the formation of virtual anodes in the direction of the myocardial fibers. Thus, the spatial distribution of the temporal excitable gap did not reflect the spatial excitable gap. The areas exhibiting wide temporal excitable gaps were areas in which the cathode-break excitation wave fronts easily invaded the spatial excitable gap via the virtual anodes. This study provides mechanistic insight into myocardial capture.

Fano-Agarwal couplings and non-rotating wave approximation in single-photon timed Dicke subradiance

NASA Astrophysics Data System (ADS)

Mirza, Imran M.; Begzjav, Tuguldur

2016-04-01

Recently a new class of single-photon timed Dicke (TD) subradiant states has been introduced with possible applications in single-photon-based quantum information storage and on demand ultrafast retrieval (Scully M. O., Phys. Rev. Lett., 115 (2015) 243602). However, the influence of any kind of virtual processes on the decay of these new kind of subradiant states has been left as an open question. In the present paper, we focus on this problem in detail. In particular, we investigate how pure Fano-Agarwal couplings and other virtual processes arising from non-rotating wave approximation impact the decay of otherwise sub- and superradiant states. In addition to the overall virtual couplings among all TD states, we also focus on the dominant role played by the couplings between specific TD states.

The Uncertainty Principle, Virtual Particles and Real Forces

ERIC Educational Resources Information Center

Jones, Goronwy Tudor

2002-01-01

This article provides a simple practical introduction to wave-particle duality, including the energy-time version of the Heisenberg Uncertainty Principle. It has been successful in leading students to an intuitive appreciation of "virtual particles" and the role they play in describing the way ordinary particles, like electrons and protons, exert…

NASA Aquarius Maps Ocean Salinity Structure

NASA Image and Video Library

2012-06-12

NASA Aquarius instrument on the Aquarius/SAC-D observatory gives an unprecedented look at a key factor involved in the formation of an oceanic wave feature in the tropical Pacific and Atlantic Oceans that influences global climate patterns.

LISA Pathfinder: An important first step towards a space-based gravitational wave observatory

NASA Astrophysics Data System (ADS)

Thorpe, James

2017-08-01

ESA's LISA Pathfinder mission was launched on Dec 3rd, 2015 and completed earlier this Summer. During this relatively short mission, Pathfinder at its two science payloads, Europe's LISA Technology Package and NASA's Disturbance Reduction System, demonstrated several techniques and technologies that enable development of a future space-based gravitational wave observatory. Most notably, Pathfinder demonstrated that the technique of drag-free flight could be utilized to place a test mass in near-perfect free-fall, with residual accelerations at the femto-g level in the milliHertz band. Additionally, technologies such as precision bonded optical structures for metrology, micropropulsion systems, and non-contact charge control, were successfully tested, retiring risk for LISA. In this talk, I will present an overview of Pathfinder's results to date and some perspective on how this success will be leveraged into realizing LISA.

Gravitational Wave (GW) Classification, Space GW Detection Sensitivities and AMIGO (Astrodynamical Middle-frequency Interferometric GW Observatory)

NASA Astrophysics Data System (ADS)

Ni, Wei-Tou

2018-01-01

After first reviewing the gravitational wave (GW) spectral classification. we discuss the sensitivities of GW detection in space aimed at low frequency band (100 nHz-100 mHz) and middle frequency band (100 mHz-10 Hz). The science goals are to detect GWs from (i) Supermassive Black Holes; (ii) Extreme-Mass-Ratio Black Hole Inspirals; (iii) Intermediate-Mass Black Holes; (iv) Galactic Compact Binaries; (v) Stellar-Size Black Hole Binaries; and (vi) Relic GW Background. The detector proposals have arm length ranging from 100 km to 1.35×109 km (9 AU) including (a) Solar orbiting detectors and (b) Earth orbiting detectors. We discuss especially the sensitivities in the frequency band 0.1-10 μHz and the middle frequency band (0.1 Hz-10 Hz). We propose and discuss AMIGO as an Astrodynamical Middlefrequency Interferometric GW Observatory.

The Millimeter Wave Observatory antenna now at INAOE-Mexico

NASA Astrophysics Data System (ADS)

Luna, A.

2017-07-01

The antenna of 5 meters in diameter of the legendary "Millimeter Wave Observatory" is now installed in the INAOE-Mexico. This historic antenna was reinstalled and was equipped with a control system and basic primary focus receivers that enabled it in teaching activities. We work on the characterization of its surface and on the development of receivers and spectrometers to allow it to do research Solar and astronomical masers. The historical contributions of this antenna to science and technology in radio astronomy, serve as the guiding force and the inspiration of the students and technicians of our postgrade in Astrophysics. It is enough to remember that it was with this antenna, that the first molecular outflow was discovered, several lines of molecular emission were discovered and it was the first antenna whose surface was characterized by holography; among many other technological and scientific contributions.

Ionospheric wave signature of the American solar eclipse on 21 August 2017 in Europe

NASA Astrophysics Data System (ADS)

Verhulst, Tobias G. W.; Stankov, Stanimir M.

2018-05-01

A total solar eclipse occurred on 21 August 2017, with the path of totality starting over the North Pacific Ocean, crossing North-America and ending over the Mid-Atlantic Ocean slightly North of the equator. As a result, a partial solar eclipse was observed as far away as the Western Europe. The ionospheric observatory in Dourbes, Belgium, was right on the edge of the partial eclipse and was exposed for a very short period of only few minutes just before the local sunset. High-resolution ionospheric measurements were carried out at the observatory with collocated digital ionosonde and GNSS receivers. The data analysis revealed a clear wave-like pattern in the ionosphere that can be seen arriving before the local onset of the eclipse. The paper details the analysis and provides a possible explanation of the observed phenomenon.

CIAO: wavefront sensors for GRAVITY

NASA Astrophysics Data System (ADS)

Scheithauer, Silvia; Brandner, Wolfgang; Deen, Casey; Adler, Tobias; Bonnet, Henri; Bourget, Pierre; Chemla, Fanny; Clenet, Yann; Delplancke, Francoise; Ebert, Monica; Eisenhauer, Frank; Esselborn, Michael; Finger, Gert; Gendron, Eric; Glauser, Adrian; Gonte, Frederic; Henning, Thomas; Hippler, Stefan; Huber, Armin; Hubert, Zoltan; Jakob, Gerd; Jochum, Lieselotte; Jocou, Laurent; Kendrew, Sarah; Klein, Ralf; Kolb, Johann; Kulas, Martin; Laun, Werner; Lenzen, Rainer; Mellein, Marcus; Müller, Eric; Moreno-Ventas, Javier; Neumann, Udo; Oberti, Sylvain; Ott, Jürgen; Pallanca, Laurent; Panduro, Johana; Ramos, Jose; Riquelme, Miguel; Rohloff, Ralf-Rainer; Rousset, Gérard; Schuhler, Nicolas; Suarez, Marcos; Zins, Gerard

2016-07-01

GRAVITY is a second generation near-infrared VLTI instrument that will combine the light of the four unit or four auxiliary telescopes of the ESO Paranal observatory in Chile. The major science goals are the observation of objects in close orbit around, or spiraling into the black hole in the Galactic center with unrivaled sensitivity and angular resolution as well as studies of young stellar objects and evolved stars. In order to cancel out the effect of atmospheric turbulence and to be able to see beyond dusty layers, it needs infrared wave-front sensors when operating with the unit telescopes. Therefore GRAVITY consists of the Beam Combiner Instrument (BCI) located in the VLTI laboratory and a wave-front sensor in each unit telescope Coudé room, thus aptly named Coudé Infrared Adaptive Optics (CIAO). This paper describes the CIAO design, assembly, integration and verification at the Paranal observatory.

Preservation and maintenance of the astronomical sites in Armenia

NASA Astrophysics Data System (ADS)

Mickaelian, A. M.

2008-01-01

Astronomy in Armenia was popular since ancient times. There are signs of astronomical observations coming from a few thousands years ago. Two ancient observatories, Karahunge and Metzamor are especially well known. Karahunge is the Armenian twin of the Stonehenge and is even older. However, there is no proper attention from the state authorities and efforts are needed for preservation of such historical-astronomical monuments. The Byurakan Astrophysical Observatory (BAO) is the modern famous Armenian observatory founded in 1946 by the outstanding scientist Victor Ambartsumian. It was one of the world astronomical centres in 1950-s to 1970-s, and at present is the largest observatory in the Middle East area. As the ancient astronomical sites, Byurakan also needs a proper attitude from the state authorities and corresponding international organizations to preserve its values and importance for the present and future astronomical activities in the region, including its rich observational archive, telescopes, and human resources. Despite all the difficulties, the Armenian astronomers keep high international level of research and display various activities organizing international meetings and schools, preparing new young generation for the future research. The Armenian Astronomical Society (ArAS) is an affiliated member of EAS. Armenia has its Virtual Observatory project (ArVO) as well. The next Joint European and National Astronomy Meeting (JENAM-2007) will be held in Yerevan, Armenia, in August 2007. There are plans to organize astronomical tours to Armenia for making observations from various sites, including the ancient observatories. The future of astronomy in Armenia strongly depends on all of this activities and the proper attention both from state authorities and society.

Radial Instabilities of a Pulsating Air Bubble in Water

DTIC Science & Technology

1990-01-30

ERASEDISPLAY GOTO 100 ELSE C CALL ERASEDISPLAY CALL EXIr ENDIF END I 1 257 3 PRCA PM SHAPE VIRTUAL DRIVE(16384) WAVE1 (16384) , WAVE2 (16L8 4 ’ ,DC(16384)3...INTEGER DRIVE, WAVE1, WAVE2 , DC INTEGER ROW, COL, NCHAR, I, OSCADR, GENADR, INFO (50) , MAXVAL, MAXV INTEGER KOUNT REAL GEN, ATEMP, WTEMP, WATT, FREQ...IREC=1 26D CALL GETWAV (1, DC, OSCADR, I REC) CALL GETWAV (2, DRIVE, OSCADR, IREC) CALL GETWAV (3, WAVE1, OSCADR, IREC) CALL GETWAV (4, WAVE2 ,OSCADR

Japanese space gravitational wave antenna DECIGO and DPF

NASA Astrophysics Data System (ADS)

Musha, Mitsuru

2017-11-01

The gravitational wave detection will open a new gravitational wave astronomy, which gives a fruitful insight about early universe or birth and death of stars. In order to detect gravitational wave, we planed a space gravitational wave detector, DECIGO (DECi-heltz Interferometer Gravitational wave Observatory), which consists of three drag-free satellites forming triangle shaped Fabry-Perot laser interferometer with the arm length of 1000 km, and whose strain sensitivity is designed to be 2x10-24 /√Hz around 0.1 Hz. Before launching DECIGO around 2030, a milestone mission named DECIGO pathfinder (DPF) is planed to be launched whose main purpose is the feasibility test of the key technologies for DECIGO. In the present paper, the conceptual design and current status of DECIGO and DPF are reviewed.

Coordinated Ground-Based and AIM Satellite Measurements of Mesospheric and Stratospheric Waves over South America

NASA Astrophysics Data System (ADS)

Taylor, M. J.; Zhao, Y.; Pautet, P. D.; Carstens, J. N.; Pugmire, J. R.; Smith, S. M.; Liu, A. Z.; Vargas, F.; Swenson, G. R.; Randall, C. E.; Bailey, S. M.; Russell, J. M., III

2016-12-01

To date, the primary research goals of the Aeronomy of Ice in the Mesosphere (AIM) satellite have focussed on investigating the occurrence, properties and dynamics of high-latitude Polar Mesospheric Clouds (PMC). With the evolution of the AIM orbit beta angle the opportunity now exists to make measurements outside the PMC region covering mid-low and equatorial latitudes. As part of the extended AIM mission science program, the AIM platform in conjunction with auxiliary ground-based measurements will be used to better understand upper atmospheric dynamics and vertical coupling due to gravity waves. Over the next 2 years AIM will take advantage of a new imaging capability of the on-board large-field CIPS UV imager to capture new data on the characteristics and spatial extents of stratospheric gravity waves near the 50 km level and their variation with latitude and season. In this study we report on initial coordinated ground-based measurements with the Andes Lidar Observatory (ALO) at Cerro Pachon, Chile ( 30°S) and nearby El Leoncito Observatory, Argentina, high in the Andes Mountains, where regular remote-sensing measurements are made using meteor radar, mesospheric airglow imagers, temperature mappers and an Na wind-temperature lidar (on a campaign basis). First coordinated measurements were made during the winter period in June 2016. AIM daytime overpasses have been analysed to search for and characterize extensive stratospheric wave events, as well as long-lived "Mountain Waves" over South America. Subsequent night-time ground-based measurements have been used to quantify wave characteristics in the mesopause region ( 80-100 km) to investigate vertical coupling. These measurements are continuing and it is planned to extend the new AIM stratospheric gravity wave data set for similar studies from a number of well-instrumented ground sites around the world.

Get the LED Out.

ERIC Educational Resources Information Center

Jewett, John W., Jr.

1991-01-01

Describes science demonstrations with light-emitting diodes that include electrical concepts of resistance, direct and alternating current, sine wave versus square wave, series and parallel circuits, and Faraday's Law; optics concepts of real and virtual images, photoresistance, and optical communication; and modern physics concepts of spectral…

Results from Binary Black Hole Simulations in Astrophysics Applications

NASA Technical Reports Server (NTRS)

Baker, John G.

2007-01-01

Present and planned gravitational wave observatories are opening a new astronomical window to the sky. A key source of gravitational waves is the merger of two black holes. The Laser Interferometer Space Antenna (LISA), in particular, is expected to observe these events with signal-to-noise ratio's in the thousands. To fully reap the scientific benefits of these observations requires a detailed understanding, based on numerical simulations, of the predictions of General Relativity for the waveform signals. New techniques for simulating binary black hole mergers, introduced two years ago, have led to dramatic advances in applied numerical simulation work. Over the last two years, numerical relativity researchers have made tremendous strides in understanding the late stages of binary black hole mergers. Simulations have been applied to test much of the basic physics of binary black hole interactions, showing robust results for merger waveform predictions, and illuminating such phenomena as spin-precession. Calculations have shown that merging systems can be kicked at up to 2500 km/s by the thrust from asymmetric emission. Recently, long lasting simulations of ten or more orbits allow tests of post-Newtonian (PN) approximation results for radiation from the last orbits of the binary's inspiral. Already, analytic waveform models based PN techniques with incorporated information from numerical simulations may be adequate for observations with current ground based observatories. As new advances in simulations continue to rapidly improve our theoretical understanding of the systems, it seems certain that high-precision predictions will be available in time for LISA and other advanced ground-based instruments. Future gravitational wave observatories are expected to make precision.

Optical Telescope System-Level Design Considerations for a Space-Based Gravitational Wave Mission

NASA Technical Reports Server (NTRS)

Livas, Jeffrey C.; Sankar, Shannon R.

2016-01-01

The study of the Universe through gravitational waves will yield a revolutionary new perspective on the Universe, which has been intensely studied using electromagnetic signals in many wavelength bands. A space-based gravitational wave observatory will enable access to a rich array of astrophysical sources in the measurement band from 0.1 to 100 mHz, and nicely complement observations from ground-based detectors as well as pulsar timing arrays by sampling a different range of compact object masses and astrophysical processes. The observatory measures gravitational radiation by precisely monitoring the tiny change in the proper distance between pairs of freely falling proof masses. These masses are separated by millions of kilometers and, using a laser heterodyne interferometric technique, the change in their proper separation is detected to approx. 10 pm over timescales of 1000 seconds, a fractional precision of better than one part in 10(exp 19). Optical telescopes are essential for the implementation of this precision displacement measurement. In this paper we describe some of the key system level design considerations for the telescope subsystem in a mission context. The reference mission for this purpose is taken to be the enhanced Laser Interferometry Space Antenna mission (eLISA), a strong candidate for the European Space Agency's Cosmic Visions L3 launch opportunity in 2034. We will review the flow-down of observatory level requirements to the telescope subsystem, particularly pertaining to the effects of telescope dimensional stability and scattered light suppression, two performance specifications which are somewhat different from the usual requirements for an image forming telescope.

Stress Wave Propagation in Larch Plantation Trees-Numerical Simulation

Treesearch

Fenglu Liu; Fang Jiang; Xiping Wang; Houjiang Zhang; Wenhua Yu

2015-01-01

In this paper, we attempted to simulate stress wave propagation in virtual tree trunks and construct two dimensional (2D) wave-front maps in the longitudinal-radial section of the trunk. A tree trunk was modeled as an orthotropic cylinder in which wood properties along the fiber and in each of the two perpendicular directions were different. We used the COMSOL...

LISA Pathfinder Spacecraft Artist Concept

NASA Image and Video Library

2015-12-03

This artist's concept shows ESA's LISA Pathfinder spacecraft, which launched on Dec. 3, 2015, from Kourou, French Guiana, will help pave the way for a mission to detect gravitational waves. LISA Pathfinder, led by the European Space Agency (ESA), is designed to test technologies that could one day detect gravitational waves. Gravitational waves, predicted by Einstein's theory of general relativity, are ripples in spacetime produced by any accelerating body. But the waves are so weak that Earth- or space-based observatories would likely only be able to directly detect such signals coming from massive astronomical systems, such as binary black holes or exploding stars. Detecting gravitational waves would be an important piece in the puzzle of how our universe began. http://photojournal.jpl.nasa.gov/catalog/PIA20196

Artificial plasma cusp generated by upper hybrid instabilities in HF heating experiments at HAARP

NASA Astrophysics Data System (ADS)

Kuo, Spencer; Snyder, Arnold

2013-05-01

High Frequency Active Auroral Research Program digisonde was operated in a fast mode to record ionospheric modifications by the HF heating wave. With the O mode heater of 3.2 MHz turned on for 2 min, significant virtual height spread was observed in the heater off ionograms, acquired beginning the moment the heater turned off. Moreover, there is a noticeable bump in the virtual height spread of the ionogram trace that appears next to the plasma frequency (~ 2.88 MHz) of the upper hybrid resonance layer of the HF heating wave. The enhanced spread and the bump disappear in the subsequent heater off ionograms recorded 1 min later. The height distribution of the ionosphere in the spread situation indicates that both electron density and temperature increases exceed 10% over a large altitude region (> 30 km) from below to above the upper hybrid resonance layer. This "mini cusp" (bump) is similar to the cusp occurring in daytime ionograms at the F1-F2 layer transition, indicating that there is a small ledge in the density profile reminiscent of F1-F2 layer transitions. Two parametric processes exciting upper hybrid waves as the sidebands by the HF heating waves are studied. Field-aligned purely growing mode and lower hybrid wave are the respective decay modes. The excited upper hybrid and lower hybrid waves introduce the anomalous electron heating which results in the ionization enhancement and localized density ledge. The large-scale density irregularities formed in the heat flow, together with the density irregularities formed through the parametric instability, give rise to the enhanced virtual height spread. The results of upper hybrid instability analysis are also applied to explain the descending feature in the development of the artificial ionization layers observed in electron cyclotron harmonic resonance heating experiments.

Armenia as a Regional Centre for Astronomy for Development activities

NASA Astrophysics Data System (ADS)

Mickaelian, A.

2015-03-01

The Byurakan Astrophysical Observatory (BAO, Armenia, http://www.bao.am) are among the candidate IAU Regional Nodes for Astronomy for Development activities. It is one of the main astronomical centers of the former Soviet Union and the Middle East region. At present there are 48 qualified researchers at BAO, including six Doctors of Science and 30 PhDs. Five important observational instruments are installed at BAO, the larger ones being 2.6m Cassegrain (ZTA-2.6) and 1m Schmidt (the one that provided the famous Markarian survey). BAO is regarded as a national scientific-educational center, where a number of activities are being organized, such as: international conferences (4 IAU symposia and 1 IAU colloquium, JENAM-2007, etc.), small workshops and discussions, international summer schools (1987, 2006, 2008 and 2010), and Olympiads. BAO collaborates with scientists from many countries. The Armenian Astronomical Society (ArAS, http://www.aras.am/) is an NGO founded in 2001; it has 93 members and it is rather active in the organization of educational, amateur, popular, promotional and other matters. The Armenian Virtual Observatory (ArVO, http://www.aras.am/Arvo/arvo.htm) is one of the 17 national VO projects forming the International Virtual Observatories Alliance (IVOA) and is the only VO project in the region serving also for educational purposes. A number of activities are planned, such as management, coordination and evaluation of the IAU programs in the area of development and education, establishment of the new IAU endowed lectureship program and organization of seminars and public lectures, coordination and initiation of fundraising activities for astronomy development, organization of regional scientific symposia, conferences and workshops, support to Galileo Teacher Training Program (GTTP), production/publication of educational and promotional materials, etc.

Flow around a corrugated wing over the range of dragonfly flight

NASA Astrophysics Data System (ADS)

Padinjattayil, Sooraj; Agrawal, Amit

2017-11-01

The dragonfly flight is very much affected by the corrugations on their wings. A PIV based study is conducted on a rigid corrugated wing for a range of Reynolds number 300-12000 and three different angles of attack (5°-15°) to understand the mechanism of dragonfly flight better. The study revealed that the shape of the corrugation plays a key role in generating vortices. The vortices trapped in the valleys of corrugation dictates the shape of a virtual airfoil around the corrugated wing. A fluid roller bearing effect is created over the virtual airfoil when the trapped vortices merge with each other. A travelling wave produced by the moving virtual boundary around the fluid roller bearings avoids the formation of boundary layer on the virtual surface, thereby leading to high aerodynamic performance. It is found that the lift coefficient increases as the number of vortices increases on the suction surface. Also, it is shown that the partially merged co- rotating vortices give higher lift as compared to fully merged vortices. Further, the virtual airfoil formed around the corrugated wing is compared with a superhydrophobic airfoil which exhibits slip on its surface; several similarities in their flow characteristics are observed. The corrugated airfoil performs superior to the superhydrophobic airfoil in the aerodynamic efficiency due to the virtual slip caused by the travelling wave.

Accessing eSDO Solar Image Processing and Visualization through AstroGrid

NASA Astrophysics Data System (ADS)

Auden, E.; Dalla, S.

2008-08-01

The eSDO project is funded by the UK's Science and Technology Facilities Council (STFC) to integrate Solar Dynamics Observatory (SDO) data, algorithms, and visualization tools with the UK's Virtual Observatory project, AstroGrid. In preparation for the SDO launch in January 2009, the eSDO team has developed nine algorithms covering coronal behaviour, feature recognition, and global / local helioseismology. Each of these algorithms has been deployed as an AstroGrid Common Execution Architecture (CEA) application so that they can be included in complex VO workflows. In addition, the PLASTIC-enabled eSDO "Streaming Tool" online movie application allows users to search multi-instrument solar archives through AstroGrid web services and visualise the image data through galleries, an interactive movie viewing applet, and QuickTime movies generated on-the-fly.

TREPS, a tool for coordinate and time transformations in space physics

NASA Astrophysics Data System (ADS)

Génot, V.; Renard, B.; Dufourg, N.; Bouchemit, M.; Lormant, N.; Beigbeder, L.; Popescu, D.; Toniutti, J.-P.; André, N.; Pitout, F.; Jacquey, C.; Cecconi, B.; Gangloff, M.

2018-01-01

We present TREPS (Transformation de REpères en Physique Spatiale) an online tool to perform coordinate transformations commonly used in planetology and heliophysics. It is based on SPICE kernels developed by NASA/NAIF. Its usage is straightforward, with a 4-step process, including various import/export options. Interoperability with external services is available through Virtual Observatory technology which is illustrated in a use case.

DaCHS: Data Center Helper Suite

NASA Astrophysics Data System (ADS)

Demleitner, Markus

2018-04-01

DaCHS, the Data Center Helper Suite, is an integrated package for publishing astronomical data sets to the Virtual Observatory. Network-facing, it speaks the major VO protocols (SCS, SIAP, SSAP, TAP, Datalink, etc). Operator-facing, many input formats, including FITS/WCS, ASCII files, and VOTable, can be processed to publication-ready data. DaCHS puts particular emphasis on integrated metadata handling, which facilitates a tight integration with the VO's Registry

Constraining the Physical Properties of Meteor Stream Particles by Light Curve Shapes Using the Virtual Meteor Observatory

NASA Technical Reports Server (NTRS)

Koschny, D.; Gritsevich, M.; Barentsen, G.

2011-01-01

Different authors have produced models for the physical properties of meteoroids based on the shape of a meteor's light curve, typically from short observing campaigns. We here analyze the height profiles and light curves of approx.200 double-station meteors from the Leonids and Perseids using data from the Virtual Meteor Observatory, to demonstrate that with this web-based meteor database it is possible to analyze very large datasets from different authors in a consistent way. We compute the average heights for begin point, maximum luminosity, and end heights for Perseids and Leonids. We also compute the skew of the light curve, usually called the F-parameter. The results compare well with other author's data. We display the average light curve in a novel way to assess the light curve shape in addition to using the F-parameter. While the Perseids show a peaked light curve, the average Leonid light curve has a more flat peak. This indicates that the particle distribution of Leonid meteors can be described by a Gaussian distribution; the Perseids can be described with a power law. The skew for Leonids is smaller than for Perseids, indicating that the Leonids are more fragile than the Perseids.

Radio data archiving system

NASA Astrophysics Data System (ADS)

Knapic, C.; Zanichelli, A.; Dovgan, E.; Nanni, M.; Stagni, M.; Righini, S.; Sponza, M.; Bedosti, F.; Orlati, A.; Smareglia, R.

2016-07-01

Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly.

A Large-scale Traveling Ionospheric Disturbance during 2015 St. Patrick's Day Geomagnetic Storm

NASA Astrophysics Data System (ADS)

Liu, J.; Zhang, D.

2016-12-01

A large scale travelling ionospheric disturbance (LSTID) observed during the geomagnetic storm on St Patrick's Day, 2015 is studied with TEC data derived from the dense GPS network in East-Asia sector and, the TEC map from the Madrigal database of MIT Haystack Observatory; with the virtual height of the ionosphere at different frequencies from the China ionosonde network; and with HF Doppler shift observations in the mid-latitude sector of China. Results show that a LSTID spanning the 80°E-140°E longitude sector occurred propagating from higher to lower latitudes during the period between 9:40 and 11:30 UT. From the continuous two-dimensional TEC perturbation maps, the propagation features of this LSTID are studied. In the west side of China between 80°E-105°E, the LSTID propagates south by west; between 105°E-115°E, the LSTID propagates almost due south, and between 115°E-135°E, the LSTID propagates south by east. This feature of the propagation orientation appears to be related to the regional geomagnetic declination. The estimated velocity is from 531 m/s to 779 m/s, with the velocity in the east side of China larger than that estimated in the west side. Moreover, the velocity estimated from the movement of the wave front of LSTID valley is smaller than that estimated from the movement of the followed wave front of crest. In addition, the calculated wavelength of the LSTID is different between longitude sectors with the wavelength estimated to be about 2000 km near 115°E versus 1700 km near 95°E. Finally, using the TEC map data from the Madrigal database of the MIT Haystack Observatory, the characteristics of the ionospheric disturbances in European sector and in North American sector are also studied. The behavior of the ionospheric disturbance is very different between the East-Asian, European, and North American sectors. A longer lasting and continuous LSTID exists in the European sector (Greenwich Meridian line). The velocity of the LSTID along Greenwich Meridian line between the 70°N-60°N is smaller than that between 60 °N-30°N. In North American sector (80°W, 115°W), the equatorward LSTID is not obvious during the prevailing LSTID period studied here (between 9:40 and 11:30 UT).

Image of the Supernova Remnant Cassiopeia A Taken by the High Energy Astronomy Observatory (HEAO)-2

NASA Technical Reports Server (NTRS)

1980-01-01

This x-ray photograph of the Supernova remnant Cassiopeia A, taken with the High Energy Astronomy Observatory (HEAO) 2/Einstein Observatory, shows that the regions with fast moving knots of material in the expanding shell are bright and clear. A faint x-ray halo, just outside the bright shell, is interpreted as a shock wave moving ahead of the expanding debris. The HEAO-2, the first imaging and largest x-ray telescope built to date, was capable of producing actual photographs of x-ray objects. Shortly after launch, the HEAO-2 was nicknamed the Einstein Observatory by its scientific experimenters in honor of the centernial of the birth of Albert Einstein, whose concepts of relativity and gravitation have influenced much of modern astrophysics, particularly x-ray astronomy. The HEAO-2, designed and developed by TRW, Inc. under the project management of the Marshall Space Flight Center, was launched aboard an Atlas/Centaur launch vehicle on November 13, 1978.

Towards the VWO Annotation Service: a Success Story of the IMAGE RPI Expert Rating System

NASA Astrophysics Data System (ADS)

Reinisch, B. W.; Galkin, I. A.; Fung, S. F.; Benson, R. F.; Kozlov, A. V.; Khmyrov, G. M.; Garcia, L. N.

2010-12-01

Interpretation of Heliophysics wave data requires specialized knowledge of wave phenomena. Users of the virtual wave observatory (VWO) will greatly benefit from a data annotation service that will allow querying of data by phenomenon type, thus helping accomplish the VWO goal to make Heliophysics wave data searchable, understandable, and usable by the scientific community. Individual annotations can be sorted by phenomenon type and reduced into event lists (catalogs). However, in contrast to the event lists, annotation records allow a greater flexibility of collaborative management by more easily admitting operations of addition, revision, or deletion. They can therefore become the building blocks for an interactive Annotation Service with a suitable graphic user interface to the VWO middleware. The VWO Annotation Service vision is an interactive, collaborative sharing of domain expert knowledge with fellow scientists and students alike. An effective prototype of the VWO Annotation Service has been in operation at the University of Massachusetts Lowell since 2001. An expert rating system (ERS) was developed for annotating the IMAGE radio plasma imager (RPI) active sounding data containing 1.2 million plasmagrams. The RPI data analysts can use ERS to submit expert ratings of plasmagram features, such as presence of echo traces resulted from reflected RPI signals from distant plasma structures. Since its inception in 2001, the RPI ERS has accumulated 7351 expert plasmagram ratings in 16 phenomenon categories, together with free-text descriptions and other metadata. In addition to human expert ratings, the system holds 225,125 ratings submitted by the CORPRAL data prospecting software that employs a model of the human pre-attentive vision to select images potentially containing interesting features. The annotation records proved to be instrumental in a number of investigations where manual data exploration would have been prohibitively tedious and expensive. Especially useful are queries of the annotation database for successive plasmagrams containing echo traces. Several success stories of the RPI ERS using this capability will be discussed, particularly in terms of how they may be extended to develop the VWO Annotation Service.

First Light Detected from Gravitational Wave Event on This Week @NASA – October 20, 2017

NASA Image and Video Library

2017-10-20

For the first time, NASA scientists have detected light tied to a gravitational-wave event. The gravitational wave – caused by an explosive merger of two neutron stars, about 130 million light-years from Earth – produced a gamma-ray burst and a rarely seen flare-up called a "kilonova". The phenomenon was captured by our Fermi, Swift, Hubble, Chandra and Spitzer missions, along with dozens of NASA-funded ground-based observatories. Also, Trio of Station Spacewalks Completed, Fresh Findings from Cassini, and Test of SLS RS-25 Flight Engine!

A preliminary summary of a seismic-refraction survey in the vicinity of the Tonto Forest Observatory, Arizona

USGS Publications Warehouse

Roller, J.C.; Jackson, W.H.; Warren, D.H.; Healy, J.H.

1964-01-01

The U.S. Geological Survey complete d a seismic-refraction survey in the vicinity of the Tonto Forest Seismological Observatory (T.F.S.O.) in April and May 1964. More than 1200 km of reversed profiles were surveyed to determine the crustal structure and crustal and upper mantle velocities in this area. The purpose of this work was to provide information on wave-propagation paths of seismic events recorded at T.F.S.O. and to improve the performance of the Observatory in locating and identifying these events. First arrivals indicate that the Mohorovicic discontinuity dips to the northeast by as much as 6 degrees under T.F.S.O., and may even be displaced vertically by as much as 5 km immediately north of the Observatory near the boundary of the Basin and Range a n d t he Colorado Plateau Provinces. A preliminary examination of the first arrivals indicates that the crust at T.F.S.O. is at least 30 km thick and is made up of at least two seismic layers. A thin veneer at the surface with a velocity of approximately 4 km/sec is underlain by a layer with a velocity of approximately 5.9 km/sec to 6.1 km/sec. An intermediate layer with velocity of 6.6 to 7.0 km/sec is probably present in the lower crust, but is not revealed by first arrivals. The velocity of seismic waves in the upper mantle is about 7.9 km/sec.

Observatories Combine to Crack Open the Crab Nebula

NASA Image and Video Library

2017-12-08

Astronomers have produced a highly detailed image of the Crab Nebula, by combining data from telescopes spanning nearly the entire breadth of the electromagnetic spectrum, from radio waves seen by the Karl G. Jansky Very Large Array (VLA) to the powerful X-ray glow as seen by the orbiting Chandra X-ray Observatory. And, in between that range of wavelengths, the Hubble Space Telescope's crisp visible-light view, and the infrared perspective of the Spitzer Space Telescope. This video starts with a composite image of the Crab Nebula, a supernova remnant that was assembled by combining data from five telescopes spanning nearly the entire breadth of the electromagnetic spectrum: the Very Large Array, the Spitzer Space Telescope, the Hubble Space Telescope, the XMM-Newton Observatory, and the Chandra X-ray Observatory. The video dissolves to the red-colored radio-light view that shows how a neutron star’s fierce “wind” of charged particles from the central neutron star energized the nebula, causing it to emit the radio waves. The yellow-colored infrared image includes the glow of dust particles absorbing ultraviolet and visible light. The green-colored Hubble visible-light image offers a very sharp view of hot filamentary structures that permeate this nebula. The blue-colored ultraviolet image and the purple-colored X-ray image shows the effect of an energetic cloud of electrons driven by a rapidly rotating neutron star at the center of the nebula. Read more: go.nasa.gov/2r0s8VC Credits: NASA, ESA, J. DePasquale (STScI)

Reengineering observatory operations for the time domain

NASA Astrophysics Data System (ADS)

Seaman, Robert L.; Vestrand, W. T.; Hessman, Frederic V.

2014-07-01

Observatories are complex scientific and technical institutions serving diverse users and purposes. Their telescopes, instruments, software, and human resources engage in interwoven workflows over a broad range of timescales. These workflows have been tuned to be responsive to concepts of observatory operations that were applicable when various assets were commissioned, years or decades in the past. The astronomical community is entering an era of rapid change increasingly characterized by large time domain surveys, robotic telescopes and automated infrastructures, and - most significantly - of operating modes and scientific consortia that span our individual facilities, joining them into complex network entities. Observatories must adapt and numerous initiatives are in progress that focus on redesigning individual components out of the astronomical toolkit. New instrumentation is both more capable and more complex than ever, and even simple instruments may have powerful observation scripting capabilities. Remote and queue observing modes are now widespread. Data archives are becoming ubiquitous. Virtual observatory standards and protocols and astroinformatics data-mining techniques layered on these are areas of active development. Indeed, new large-aperture ground-based telescopes may be as expensive as space missions and have similarly formal project management processes and large data management requirements. This piecewise approach is not enough. Whatever challenges of funding or politics facing the national and international astronomical communities it will be more efficient - scientifically as well as in the usual figures of merit of cost, schedule, performance, and risks - to explicitly address the systems engineering of the astronomical community as a whole.

High-Frequency Gravitational Wave research and application to exoplanet studies

NASA Astrophysics Data System (ADS)

Baker, R. M. L., Jr.

2017-10-01

A discussion of the history of High-Frequency Gravitational Wave (HFGW) research is first presented. Over the years until modern times, starting with the first mention of Gravitational Waves by Poincaré in 1905 and the definition of HFGWs in 1961 by Robert L. Forward, the discussion continues concerning the international research efforts to detect HFGWs. The article highlights the accomplishments of HFGW researchers in China, Russia, Ukraine, England, Australia, Japan, Germany, Spain, Italy, and the United States. Comparisons are made with Low-Frequency Gravitational Wave (LFGW) research, especially concerning the Laser Interferometer Gravitational Observatory or LIGO. In fine, there are presented several interesting perspectives concerning cosmology, the speed of time and, especially, exoplanet applications of HFGWs.

An IBEM solution to the scattering of plane SH-waves by a lined tunnel in elastic wedge space

NASA Astrophysics Data System (ADS)

Liu, Zhongxian; Liu, Lei

2015-02-01

The indirect boundary element method (IBEM) is developed to solve the scattering of plane SH-waves by a lined tunnel in elastic wedge space. According to the theory of single-layer potential, the scattered-wave field can be constructed by applying virtual uniform loads on the surface of lined tunnel and the nearby wedge surface. The densities of virtual loads can be solved by establishing equations through the continuity conditions on the interface and zero-traction conditions on free surfaces. The total wave field is obtained by the superposition of free field and scattered-wave field in elastic wedge space. Numerical results indicate that the IBEM can solve the diffraction of elastic wave in elastic wedge space accurately and efficiently. The wave motion feature strongly depends on the wedge angle, the angle of incidence, incident frequency, the location of lined tunnel, and material parameters. The waves interference and amplification effect around the tunnel in wedge space is more significant, causing the dynamic stress concentration factor on rigid tunnel and the displacement amplitude of flexible tunnel up to 50.0 and 17.0, respectively, more than double that of the case of half-space. Hence, considerable attention should be paid to seismic resistant or anti-explosion design of the tunnel built on a slope or hillside.

WC WAVE - Integrating Diverse Hydrological-Modeling Data and Services Into an Interoperable Geospatial Infrastructure

NASA Astrophysics Data System (ADS)

Hudspeth, W. B.; Baros, S.; Barrett, H.; Savickas, J.; Erickson, J.

2015-12-01

WC WAVE (Western Consortium for Watershed Analysis, Visualization and Exploration) is a collaborative research project between the states of Idaho, Nevada, and New Mexico that is funded under the National Science Foundation's Experimental Program to Stimulate Competitive Research (EPSCoR). The goal of the project is to understand and document the effects of climate change on interactions between precipitation, vegetation growth, soil moisture and other landscape properties. These interactions are modeled within a framework we refer to as a virtual watershed (VW), a computer infrastructure that simulates watershed dynamics by linking scientific modeling, visualization, and data management components into a coherent whole. Developed and hosted at the Earth Data Analysis Center, University of New Mexico, the virtual watershed has a number of core functions which include: a) streamlined access to data required for model initialization and boundary conditions; b) the development of analytic scenarios through interactive visualization of available data and the storage of model configuration options; c) coupling of hydrological models through the rapid assimilation of model outputs into the data management system for access and use by sequent models. The WC-WAVE virtual watershed accomplishes these functions by provision of large-scale vector and raster data discovery, subsetting, and delivery via Open Geospatial Consortium (OGC) and REST web service standards. Central to the virtual watershed is the design and use of an innovative array of metadata elements that permits the stepwise coupling of diverse hydrological models (e.g. ISNOBAL, PRMS, CASiMiR) and input data to rapidly assess variation in outcomes under different climatic conditions. We present details on the architecture and functionality of the virtual watershed, results from three western U.S. watersheds, and discuss the realized benefits to watershed science of employing this integrated solution.

LISA Pathfinder and eLISA news

NASA Technical Reports Server (NTRS)

Thorpe, James Ira; Mueller, Guido

2014-01-01

Two important gatherings of the space-based gravitational-wave detector community were held in Zurich, Switzerland this past March. The first was a meeting of the Science Working Team for LISA Pathfinder (LPF), a dedicated technology demonstrator mission for a future LISA-like gravitational wave observatory. LPF is entering an extremely exciting phase with launch less than 15 months away. All flight components for both the European science payload, known as the LISA Technology Package (LTP), and the NASA science payload, known as the Space Technology 7 Disturbance Reduction System (ST7-DRS), have been delivered and are undergoing integration. The final flight component for the spacecraft bus, a cold-gas thruster based on the successful GAIA design, will be delivered later this year. Current focus is on completing integration of the science payload (see Figures 1 and 2) and preparation for operations and data analysis. After a launch in Summer 2015, LPF will take approximately 90 days to reach its operational orbit around the Earth-Sun Lagrange point (L1), where it will begin science operations. After 90 days of LTP operations followed by 90 days of DRS operations, LPF will have completed its prime mission of paving the way for a space-based observatory of gravitational waves in the milliHertz band. Immediately following the meeting of the LPF team, the eLISA consortium held its third progress meeting. The consortium (www.elisascience.org) is the organizing body of the European space-based gravitational-wave community, and it was responsible for the "The Gravitational Universe" whitepaper that resulted in the November 2013 election of a gravitational-wave science theme for ESA's Cosmic Visions L3 opportunity. In preparation for an L3 mission concept call, which is expected later this decade, and for launch in the mid 2030s, the eLISA consortium members are coordinating technology development and mission study activities which will build on the LPF results. The final mission concept is expected to include some international (non-European) contributions, and NASA has expressed an interest in participating in this ground-breaking mission. The US research community supports such a collaboration, or any other mission scenario that achieves the high-priority science of a space-based gravitational-wave observatory at the earliest possible date.

Astronomy research at the Aerospace Corporation. [research projects - NASA programs

NASA Technical Reports Server (NTRS)

Paulikas, G. A.

1974-01-01

This report reviews the astronomy research carried out at The Aerospace Corporation during 1974. The report describes the activities of the San Fernando Observatory, the research in millimeter wave radio astronomy as well as the space astronomy research.

A selective array activation method for the generation of a focused source considering listening position.

PubMed

Song, Min-Ho; Choi, Jung-Woo; Kim, Yang-Hann

2012-02-01

A focused source can provide an auditory illusion of a virtual source placed between the loudspeaker array and the listener. When a focused source is generated by time-reversed acoustic focusing solution, its use as a virtual source is limited due to artifacts caused by convergent waves traveling towards the focusing point. This paper proposes an array activation method to reduce the artifacts for a selected listening point inside an array of arbitrary shape. Results show that energy of convergent waves can be reduced up to 60 dB for a large region including the selected listening point. © 2012 Acoustical Society of America

PECULIAR STATIONARY EUV WAVE FRONTS IN THE ERUPTION ON 2011 MAY 11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandra, R.; Fulara, A.; Chen, P. F.

We present and interpret the observations of extreme ultraviolet (EUV) waves associated with a filament eruption on 2011 May 11. The filament eruption also produces a small B-class two ribbon flare and a coronal mass ejection. The event is observed by the Solar Dynamic Observatory with high spatio-temporal resolution data recorded by the Atmospheric Imaging Assembly. As the filament erupts, we observe two types of EUV waves (slow and fast) propagating outwards. The faster EUV wave has a propagation velocity of ∼500 km s{sup −1} and the slower EUV wave has an initial velocity of ∼120 km s{sup −1}. Wemore » report, for the first time, that not only does the slower EUV wave stop at a magnetic separatrix to form bright stationary fronts, but also the faster EUV wave transits a magnetic separatrix, leaving another stationary EUV front behind.« less

International Virtual Observatory System for Water Resources Information

NASA Astrophysics Data System (ADS)

Leinenweber, Lewis; Bermudez, Luis

2013-04-01

Sharing, accessing, and integrating hydrologic and climatic data have been identified as a critical need for some time. The current state of data portals, standards, technologies, activities, and expertise can be leverage to develop an initial operational capability for a virtual observatory system. This system will allow to link observations data with stream networks and models, and to solve semantic inconsistencies among communities. Prototyping a virtual observatory system is an inter-disciplinary, inter-agency and international endeavor. The Open Geospatial Consortium (OGC) within the OGC Interoperability Program provides the process and expertise to run such collaborative effort. The OGC serves as a global forum for the collaboration of developers and users of spatial data products and services, and to advance the development of international standards for geospatial interoperability. The project coordinated by OGC that is advancing an international virtual observatory system for water resources information is called Climatology-Hydrology Information Sharing Pilot, Phase 1 (CHISP-1). It includes observations and forecasts in the U.S. and Canada levering current networks and capabilities. It is designed to support the following use cases: 1) Hydrologic modeling for historical and near-future stream flow and groundwater conditions. Requires the integration of trans-boundary stream flow and groundwater well data, as well as national river networks (US NHD and Canada NHN) from multiple agencies. Emphasis will be on time series data and real-time flood monitoring. 2) Modeling and assessment of nutrient load into the lakes. Requires accessing water-quality data from multiple agencies and integrating with stream flow information for calculating loads. Emphasis on discrete sampled water quality observations, linking those to specific NHD stream reaches and catchments, and additional metadata for sampled data. The key objectives of these use cases are: 1) To link observations data to the stream network, enabling queries of conditions upstream from a given location to return all relevant gages and well locations. This is currently not practical with the data sources available. 2) To bridge differences in semantics across information models and processes used by the various data producers, to improve the hydrologic and water quality modeling capabilities. Other expected benefits to be derived from this project include: - Leverage a large body of existing data holdings and related activities of multiple agencies in the US and Canada. - Influence data and metadata standards used internationally for web-based information sharing, through multiple agency cooperation and OGC standards setting process. - Reduction of procurement risk through partnership-based development of an initial operating capability verses the cost for building a fully operational system using a traditional "waterfall approach". - Identification and clarification of what is possible, and of the key technical and non-technical barriers to continued progress in sharing and integrating hydrologic and climatic information. - Promote understanding and strengthen ties within the hydro-climatic community. This is anticipated to be the first phase of a multi-phase project, with future work on forecasting the hydrologic consequences of extreme weather events, and enabling more sophisticated water quality modeling.

Gravitational waves — A review on the theoretical foundations of gravitational radiation

NASA Astrophysics Data System (ADS)

Dirkes, Alain

2018-05-01

In this paper, we review the theoretical foundations of gravitational waves in the framework of Albert Einstein’s theory of general relativity. Following Einstein’s early efforts, we first derive the linearized Einstein field equations and work out the corresponding gravitational wave equation. Moreover, we present the gravitational potentials in the far away wave zone field point approximation obtained from the relaxed Einstein field equations. We close this review by taking a closer look on the radiative losses of gravitating n-body systems and present some aspects of the current interferometric gravitational waves detectors. Each section has a separate appendix contribution where further computational details are displayed. To conclude, we summarize the main results and present a brief outlook in terms of current ongoing efforts to build a spaced-based gravitational wave observatory.

Virtual Worlds for Virtual Organizing

NASA Astrophysics Data System (ADS)

Rhoten, Diana; Lutters, Wayne

The members and resources of a virtual organization are dispersed across time and space, yet they function as a coherent entity through the use of technologies, networks, and alliances. As virtual organizations proliferate and become increasingly important in society, many may exploit the technical architecture s of virtual worlds, which are the confluence of computer-mediated communication, telepresence, and virtual reality originally created for gaming. A brief socio-technical history describes their early origins and the waves of progress followed by stasis that brought us to the current period of renewed enthusiasm. Examination of contemporary examples demonstrates how three genres of virtual worlds have enabled new arenas for virtual organizing: developer-defined closed worlds, user-modifiable quasi-open worlds, and user-generated open worlds. Among expected future trends are an increase in collaboration born virtually rather than imported from existing organizations, a tension between high-fidelity recreations of the physical world and hyper-stylized imaginations of fantasy worlds, and the growth of specialized worlds optimized for particular sectors, companies, or cultures.

Brown Dwarfs: A New Class of Stellar Lighthouse

NASA Astrophysics Data System (ADS)

2007-04-01

Brown dwarfs, thought just a few years ago to be incapable of emitting any significant amounts of radio waves, have been discovered putting out extremely bright "lighthouse beams" of radio waves, much like pulsars. A team of astronomers made the discovery using the National Science Foundation's Very Large Array (VLA) radio telescope. Artist's Conception of Brown Dwarf Artist's conception of "mini-aurorae" at poles of brown dwarf, producing beams of strong radio emission. CREDIT: Hallinan et al., NRAO/AUI/NSF Click on image for page of graphics and full information "These beams rotate with the brown dwarf, and we see them when the beam passes over the Earth. This is the same way we see pulses from pulsars," said Gregg Hallinan of the National University of Ireland Galway. "We now think brown dwarfs may be a missing link between pulsars and planets in our own Solar System, which also emit, but more weakly," he added. Brown dwarfs are enigmatic objects that are too small to be stars but too large to be planets. They are sometimes called "failed stars" because they have too little mass to trigger hydrogen fusion reactions at their cores, the source of the energy output in larger stars. With roughly 15 to 80 times the mass of Jupiter, the largest planet in our Solar System, brown dwarfs were long thought to exist. However, it was not until 1995 that astronomers were able to actually find one. A few dozen now are known. In 2001, a group of summer students at the National Radio Astronomy Observatory used the VLA to observe a brown dwarf, even though they had been told by seasoned astronomers that brown dwarfs are not observable at radio wavelengths. Their discovery of a strong flare of radio emission from the object surprised astronomers and the students' scientific paper on the discovery was published in the prestigous scientific journal Nature. Hallinan and his team observed a set of brown dwarfs with the VLA last year, and found that three of the objects emit extremely strong, repeating pulses of radio waves. They concluded that the pulses come from beams emitted from the magnetic poles of the brown dwarfs. This is similar to the beamed emission from pulsars, which are superdense neutron stars, and much more massive than brown dwarfs. The characteristics of the beamed radio emission from the brown dwarfs suggest to the scientists that it is produced by a mechanism also seen at work in planets, including Jupiter and Earth. This process involves electrons interacting with the planet's magnetic field to produce radio waves that then are amplified, or strengthened, by natural masers that amplify radio waves the same way a laser amplifies light waves. "The brown dwarfs we observed are between planets and pulsars in the strength of their radio emissions," said Aaron Golden, also of the National University of Ireland Galway. "While we don't think the mechanism that's producing the radio waves in brown dwarfs is exactly the same as that producing pulsar radio emissions, we think there may be enough similarities that further study of brown dwarfs may help unlock some of the mysteries about how pulsars work," he said. While pulsars were discovered 40 years ago, scientists still do not understand the details of how their strong radio emissions are produced. The brown dwarfs rotate at a much more leisurely pace than pulsars. While pulsars rotate -- and produce observed pulses -- typically several times a second to hundreds of times a second, the brown dwarfs observed with the VLA are showing pulses roughly once every two to three hours. Hallinan and Golden worked with Stephen Bourke and Caoilfhionn Lane, also of the National University of Ireland Galway; Tony Antonova and Gerry Doyle of Armagh Observatory in Northern Ireland; Robert Zavala and Fred Vrba of the U.S.Naval Observatory in Flagstaff, Arizona; Walter Brisken of the National Radio Astronomy Observatory in Socorro, New Mexico; and Richard Boyle of the Vatican Observatory Research Group at Steward Observatory in Arizona. The scientists presented their results to the Royal Astronomical Society's National Astronomy Meeting at the University of Central Lancashire in the United Kingdom. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. This work was supported by Science Foundation Ireland under its Research Frontiers Programme, the Higher Education Authority's Programme for Research in Third Level Institutions, and the Irish Research Council for Science, Engineering and Technology.

Exploring the Unknown: Cabled Ocean Observatory Data and Discovery in University Education

NASA Astrophysics Data System (ADS)

Pelz, M.; Scherwath, M.; Riddell, D. J.; Hoeberechts, M.; Bourdeault-Fournier, A.; Schine, J.; Sammarco, P. M. P.

2016-12-01

Cabled ocean observatories, which supply continuous power and Internet connectivity to subsea instruments from the coast to the deep sea, enable us to extend our reach into unexplored regions of the ocean. Sensors become our eyes and ears in this mysterious world, allowing instructors and students to have a virtual presence in an environment that is otherwise inaccessible for human study. Networks of always-on sensors in habitats as diverse as submarine canyons, hypoxic marine basins, and active hydrothermal vent systems provide unprecedented opportunities for students to ask real scientific questions and to answer those questions with real data. Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates coastal and deep ocean cabled observatories, including VENUS and NEPTUNE off the west coast of British Columbia, Canada. ONC supports instructors in the creation of lab and course materials using observatory data. Data from the observatories are freely accessible through a web-based interface, which allows students to continue their investigations beyond the in-class activities. Here, we present three examples of the application of data from Ocean Networks Canada's cabled observatories in post-secondary education: an undergraduate lab in marine ecology in which students investigate the factors affecting spatial variation in benthic animal diversity using ocean sensor data and video footage from cameras on the seafloor; an undergraduate field course in acoustic ethnography in which students incorporate recordings from ONC's hydrophone arrays; and a graduate student "research derby" in which students propose hypotheses that can be investigated using ONC data in whole or in part, with rewards for those successful in publishing the results of their study in a peer-reviewed journal within two years.

Visualizing astronomy data using VRML

NASA Astrophysics Data System (ADS)

Beeson, Brett; Lancaster, Michael; Barnes, David G.; Bourke, Paul D.; Rixon, Guy T.

2004-09-01

Visualisation is a powerful tool for understanding the large data sets typical of astronomical surveys and can reveal unsuspected relationships and anomalous regions of parameter space which may be difficult to find programatically. Visualisation is a classic information technology for optimising scientific return. We are developing a number of generic on-line visualisation tools as a component of the Australian Virtual Observatory project. The tools will be deployed within the framework of the International Virtual Observatory Alliance (IVOA), and follow agreed-upon standards to make them accessible by other programs and people. We and our IVOA partners plan to utilise new information technologies (such as grid computing and web services) to advance the scientific return of existing and future instrumentation. Here we present a new tool - VOlume - which visualises point data. Visualisation of astronomical data normally requires the local installation of complex software, the downloading of potentially large datasets, and very often time-consuming and tedious data format conversions. VOlume enables the astronomer to visualise data using just a web browser and plug-in. This is achieved using IVOA standards which allow us to pass data between Web Services, Java Servlet Technology and Common Gateway Interface programs. Data from a catalogue server can be streamed in eXtensible Mark-up Language format to a servlet which produces Virtual Reality Modeling Language output. The user selects elements of the catalogue to map to geometry and then visualises the result in a browser plug-in such as Cortona or FreeWRL. Other than requiring an input VOTable format file, VOlume is very general. While its major use will likely be to display and explore astronomical source catalogues, it can easily render other important parameter fields such as the sky and redshift coverage of proposed surveys or the sampling of the visibility plane by a rotation-synthesis interferometer.

The Canadian Astronomy Data Centre

NASA Astrophysics Data System (ADS)

Ball, Nicholas M.; Schade, D.; Astronomy Data Centre, Canadian

2011-01-01

The Canadian Astronomy Data Centre (CADC) is the world's largest astronomical data center, holding over 0.5 Petabytes of information, and serving nearly 3000 astronomers worldwide. Its current data collections include BLAST, CFHT, CGPS, FUSE, Gemini, HST, JCMT, MACHO, MOST, and numerous other archives and services. It provides extensive data archiving, curation, and processing expertise, via projects such as MegaPipe, and enables substantial day-to-day collaboration between resident astronomers and computer specialists. It is a stable, powerful, persistent, and properly supported environment for the storage and processing of large volumes of data, a condition that is now absolutely vital for their science potential to be exploited by the community. Through initiatives such as the Common Archive Observation Model (CAOM), the Canadian Virtual Observatory (CVO), and the Canadian Advanced Network for Astronomical Research (CANFAR), the CADC is at the global forefront of advancing astronomical research through improved data services. The CAOM aims to provide homogeneous data access, and hence viable interoperability between a potentially unlimited number of different data collections, at many wavelengths. It is active in the definition of numerous emerging standards within the International Virtual Observatory, and several datasets are already available. The CANFAR project is an initiative to make cloud computing for storage and data-intensive processing available to the community. It does this via a Virtual Machine environment that is equivalent to managing a local desktop. Several groups are already processing science data. CADC is also at the forefront of advanced astronomical data analysis, driven by the science requirements of astronomers both locally and further afield. The emergence of 'Astroinformatics' promises to provide not only utility items like object classifications, but to directly enable new science by accessing previously undiscovered or intractable information. We are currently in the early stages of implementing Astroinformatics tools, such as machine learning, on CANFAR.

Space-Based Gravitational-Wave Observations as Tools for Testing General Relativity

NASA Technical Reports Server (NTRS)

Will, Clifford M.

2004-01-01

We continued a project, to analyse the ways in which detection and study of gravitational waves could provide quantitative tests of general relativity, with particular emphasis on waves that would be detectable by space-based observatories, such as LISA. This work had three foci: 1) Tests of scalar-tensor theories of gravity that, could be done by analyzing gravitational waves from neutron stars inspiralling into massive black holes, as detectable by LISA; 2) Study of alternative theories of gravity in which the graviton could be massive, and of how gravitational-wave observations by space-based detectors, solar-system tests, and cosmological observations could constrain such theories; and 3) Study of gravitational-radiation back reaction of particles orbiting black holes in general relativity, with emphasis on the effects of spin.

Limiting the Effects of Earthquake Shaking on Gravitational-Wave Interferometers

NASA Astrophysics Data System (ADS)

Perry, M. R.; Earle, P. S.; Guy, M. R.; Harms, J.; Coughlin, M.; Biscans, S.; Buchanan, C.; Coughlin, E.; Fee, J.; Mukund, N.

2016-12-01

Second-generation ground-based gravitational wave interferometers such as the Laser Interferometer Gravitational-wave Observatory (LIGO) are susceptible to high-amplitude waves from teleseismic events, which can cause astronomical detectors to fall out of mechanical lock (lockloss). This causes the data to be useless for gravitational wave detection around the time of the seismic arrivals and for several hours thereafter while the detector stabilizes enough to return to the locked state. The down time can be reduced if advance warning of impending shaking is received and the impact is suppressed in the isolation system with the goal of maintaining lock even at the expense of increased instrumental noise. Here we describe an early warning system for modern gravitational-wave observatories. The system relies on near real-time earthquake alerts provided by the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA). Hypocenter and magnitude information is typically available within 5 to 20 minutes of the origin time of significant earthquakes, generally before the arrival of high-amplitude waves from these teleseisms at LIGO. These alerts are used to estimate arrival times and ground velocities at the gravitational wave detectors. In general, 94% of the predictions for ground-motion amplitude are within a factor of 5 of measured values. The error in both arrival time and ground-motion prediction introduced by using preliminary, rather than final, hypocenter and magnitude information is minimal with about 90% of the events falling within a factor of 2 of the final predicted value. By using a Machine Learning Algorithm, we develop a lockloss prediction model that calculates the probability that a given earthquake will prevent a detector from taking data. Our initial results indicate that by using detector control configuration changes, we could save lockloss from 40-100 earthquake events in a 6-month time-period.

Directed searches for continuous gravitational waves from spinning neutron stars in binary systems

NASA Astrophysics Data System (ADS)

Meadors, Grant David

2014-09-01

Gravitational wave detectors such as the Laser Interferometer Gravitational-wave Observatory (LIGO) seek to observe ripples in space predicted by General Relativity. Black holes, neutron stars, supernovae, the Big Bang and other sources can radiate gravitational waves. Original contributions to the LIGO effort are presented in this thesis: feedforward filtering, directed binary neutron star searches for continuous waves, and scientific outreach and education, as well as advances in quantum optical squeezing. Feedforward filtering removes extraneous noise from servo-controlled instruments. Filtering of the last science run, S6, improves LIGO's astrophysical range (+4.14% H1, +3.60% L1: +12% volume) after subtracting noise from auxiliary length control channels. This thesis shows how filtering enhances the scientific sensitivity of LIGO's data set during and after S6. Techniques for non-stationarity and verifying calibration and integrity may apply to Advanced LIGO. Squeezing is planned for future interferometers to exceed the standard quantum limit on noise from electromagnetic vacuum fluctuations; this thesis discusses the integration of a prototype squeezer at LIGO Hanford Observatory and impact on astrophysical sensitivity. Continuous gravitational waves may be emitted by neutron stars in low-mass X-ray binary systems such as Scorpius X-1. The TwoSpect directed binary search is designed to detect these waves. TwoSpect is the most sensitive of 4 methods in simulated data, projecting an upper limit of 4.23e-25 in strain, given a year-long data set at an Advanced LIGO design sensitivity of 4e-24 Hz. (-1/2). TwoSpect is also used on real S6 data to set 95% confidence upper limits (40 Hz to 2040 Hz) on strain from Scorpius X-1. A millisecond pulsar, X-ray transient J1751-305, is similarly considered. Search enhancements for Advanced LIGO are proposed. Advanced LIGO and fellow interferometers should detect gravitational waves in the coming decade. Methods in these thesis will benefit both the instrumental and analytical sides of observation.

Gamma-ray-burst beaming and gravitational-wave observations.

PubMed

Chen, Hsin-Yu; Holz, Daniel E

2013-11-01

Using the observed rate of short-duration gamma-ray bursts (GRBs) it is possible to make predictions for the detectable rate of compact binary coalescences in gravitational-wave detectors. We show that the nondetection of mergers in the existing LIGO/Virgo data constrains the beaming angles and progenitor masses of gamma-ray bursts, although these limits are fully consistent with existing expectations. We make predictions for the rate of events in future networks of gravitational-wave observatories, finding that the first detection of a neutron-star-neutron-star binary coalescence associated with the progenitors of short GRBs is likely to happen within the first 16 months of observation, even in the case of only two observatories (e.g., LIGO-Hanford and LIGO-Livingston) operating at intermediate sensitivities (e.g., advanced LIGO design sensitivity, but without signal recycling mirrors), and assuming a conservative distribution of beaming angles (e.g., all GRBs beamed within θ(j) = 30°). Less conservative assumptions reduce the waiting time until first detection to a period of weeks to months, with an event detection rate of >/~10/yr. Alternatively, the compact binary coalescence model of short GRBs can be ruled out if a binary is not seen within the first two years of operation of a LIGO-Hanford, LIGO-Livingston, and Virgo network at advanced design sensitivity. We also demonstrate that the gravitational wave detection rate of GRB triggered sources (i.e., those seen first in gamma rays) is lower than the rate of untriggered events (i.e., those seen only in gravitational waves) if θ(j)≲30°, independent of the noise curve, network configuration, and observed GRB rate. The first detection in gravitational waves of a binary GRB progenitor is therefore unlikely to be associated with the observation of a GRB.

Coronal Seismology: The Search for Propagating Waves in Coronal Loops

NASA Astrophysics Data System (ADS)

Schad, Thomas A.; Seeley, D.; Keil, S. L.; Tomczyk, S.

2007-05-01

We report on Doppler observations of the solar corona obtained in the Fe XeXIII 1074.7nm coronal emission line with the HAO Coronal Multi-Channel Polarimeter (CoMP) mounted on the NSO Coronal One Shot coronagraph located in the Hilltop Facility of NSO/Sacramento Peak. The COMP is a tunable filtergraph instrument that records the entire corona from the edge of the occulting disk at approximately 1.03 Rsun out to 1.4 Rsun with a spatial resolution of about 4” x 4”. COMP can be rapidly scanned through the spectral line while recording orthogonal states of linear and circular polarization. The two dimensional spatial resolution allows us to correlate temporal fluctuations observed in one part of the corona with those seen at other locations, in particular along coronal loops. Using cross spectral analysis we find that the observations reveal upward propagating waves that are characterized by Doppler shifts with rms velocities of 0.3 km/s, peak wave power in the 3-5 mHz frequency range, and phase speeds 1-3 Mm/s. The wave trajectories are consistent with the direction of the magnetic field inferred from the linear polarization measurements. We discuss the phase and coherence of these waves as a function of height in the corona and relate our findings to previous observations. The observed waves appear to be Alfvenic in character. "Thomas Schad was supported through the National Solar Observatory Research Experiences for Undergraduate (REU) site program, which is co-funded by the Department of Defense in partnership with the National Science Foundation REU Program." Daniel Seeley was supported through the National Solar Observatory Research Experience for Teachers (RET) site program, which is funded by the National Science Foundation RET program.

The NANOGrav Observing Program: High-precision Millisecond Pulsar Timing and the Search for Nanohertz Gravitational Waves

NASA Astrophysics Data System (ADS)

Nice, David; NANOGrav

2018-01-01

The North American Observatory for Nanohertz Gravitational Waves (NANOGrav) collaboration is thirteen years into a program of long-term, high-precision millisecond pulsar timing, undertaken with the goal of detecting and characterization nanohertz gravitational waves (i.e., gravitational waves with periods of many years) by measuring their effect on observed pulse arrival times. Our primary instruments are the Arecibo Observatory, used to observe 37 pulsars with declinations between 0 and 39 degrees; and the Green Bank Telescope, used for 24 pulsars, of which 22 are outside the Arecibo range, and 2 are overlaps with the Arecibo source list. Additional observations are made with the VLA and (soon) CHIME.Most pulsars in our program are observed at intervals of three to four weeks, and seven are observed weekly. Observations of each pulsar are made over a wide range of radio frequencies at each epoch in order to measure and mitigate effects of the ionized interstellar medium on the pulse arrival times. Our targets are pulsars for which we can achieve timing precision of 1 microsecond or better in at each epoch; we achieve precision better than 100 nanoseconds in the best cases. Observing a large number of pulsars will allow for robust measurements of gravitational waves by analyzing correlations in the timing of pairs of pulsars depending on their separation on the sky. Our data are pooled with data from telescopes worldwide via the International Pulsar Timing Array (IPTA) collaboration, further increasing our sensitivity to gravitational waves.We release data at regular intervals. We will describe the NANOGrav 5-, 9- and 11-year data sets and give a status report on the NANOGrav 12.5-year data set.

GRAAL on the mountaintop

NASA Astrophysics Data System (ADS)

Paufique, Jérôme; Madec, Pierre-Yves; Kolb, Johann; Kuntschner, Harald; Argomedo, Javier; Kiekebusch, Mario J.; Donaldson, Robert H.; Arsenault, Robin; Siebenmorgen, Ralf; Soenke, Christian; Tordo, Sebastien; Conzelmann, Ralf D.; Jost, Andreas; Reyes-Moreno, Javier; Downing, Mark; Hibon, Pascale; Valenzuela, Jose Javier; Haguenauer, Pierre

2016-07-01

GRAAL is the adaptive optics module feeding the wide-field IR imager HAWK-I at the VLT observatory. As part of the adaptive optics facility, GRAAL is equipped with 4 Laser-guide star wave-front sensors and provides a large field-of-view, ground layer correction system to HAWK-I. After a successful testing in Europe, the module has been re-assembled in Chile and installed at the Nasmyth-A platform of Yepun, the fourth Unit telescope of the observatory. We report on the installation of GRAAL on the mountain and on its first testing in stand-alone and on-sky.

METEOSPACE, solar monitoring and space weather at Calern observatory

NASA Astrophysics Data System (ADS)

Corbard, T.; Malherbe, J.-M.; Crussaire, D.; Morand, F.; Ruty, F.; Biree, L.; Aboudarham, J.; Fuller, N.; Renaud, C.; Meftah, M.

2016-12-01

METEOSPACE is a new partnership project between the Paris Observatory (OP), the Observatoire de la Côte d'Azur (OCA), the French Air Force and a service company (LUNA technology) for the development and operation of a set of small telescopes Hα / Ca II K / Ca II H / G band to be installed at on the Calern plateau (OCA). The objective is to monitor solar activity for both research and its applications in space weather through continuous optical observations of the dynamic phenomena that are visible in the chromosphere: eruptions, destabilization of the filaments triggering coronal mass ejections and associated Moreton waves.

Astronomy and astrophysics for the 1980's, volume 1

NASA Technical Reports Server (NTRS)

1982-01-01

The programs recommended address the most significant questions that confront contemporary astronomy and fall into three general categories: prerequisites for research initiatives, including instrumentation and detectors, theory and data analysis, computational facilities, laboratory astrophysics, and technical support at ground-based observatories; programs including an Advanced X-ray Astrophysics Facility, a Very-Long Baseline Array, a Technology Telescope and a Large Deployable Reflector; and programs for study and development, including X-ray observatories in space, instruments for the detection of gravitational waves from astronomical objects, and long duration spaceflights of infrared telescopes. Estimated costs of these programs are provided.

Astronomy and astrophysics for the 1980's, volume 1

NASA Astrophysics Data System (ADS)

The programs recommended address the most significant questions that confront contemporary astronomy and fall into three general categories: prerequisites for research initiatives, including instrumentation and detectors, theory and data analysis, computational facilities, laboratory astrophysics, and technical support at ground-based observatories; programs including an Advanced X-ray Astrophysics Facility, a Very-Long Baseline Array, a Technology Telescope and a Large Deployable Reflector; and programs for study and development, including X-ray observatories in space, instruments for the detection of gravitational waves from astronomical objects, and long duration spaceflights of infrared telescopes. Estimated costs of these programs are provided.

White Dwarf Model Atmospheres: Synthetic Spectra for Supersoft Sources

NASA Astrophysics Data System (ADS)

Rauch, Thomas

2013-01-01

The Tübingen NLTE Model-Atmosphere Package (TMAP) calculates fully metal-line blanketed white dwarf model atmospheres and spectral energy distributions (SEDs) at a high level of sophistication. Such SEDs are easily accessible via the German Astrophysical Virtual Observatory (GAVO) service TheoSSA. We discuss applications of TMAP models to (pre) white dwarfs during the hottest stages of their stellar evolution, e.g. in the parameter range of novae and supersoft sources.

Planetary Sciences Interoperability at VO Paris Data Centre

NASA Astrophysics Data System (ADS)

Le Sidaner, P.; Aboudarham, J.; Birlan, M.; Briot, D.; Bonnin, X.; Cecconi, B.; Chauvin, C.; Erard, S.; Henry, F.; Lamy, L.; Mancini, M.; Normand, J.; Popescu, F.; Roques, F.; Savalle, R.; Schneider, J.; Shih, A.; Thuillot, W.; Vinatier, S.

2015-10-01

The Astronomy community has been developing interoperability since more than 10 years, by standardizing data access, data formats, and metadata. This international action is led by the International Virtual Observatory Alliance (IVOA). Observatoire de Paris is an active participant in this project. All actions on interoperability, data and service provision are centralized in and managed by VOParis Data Centre (VOPDC). VOPDC is a coordinated project from all scientific departments of Observatoire de Paris..

Virtual gap dielectric wall accelerator

DOEpatents

Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

2013-11-05

A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

The changing face of terrorism in the 21st century: the communications revolution and the virtual community of hatred.

PubMed

Post, Jerrold M; McGinnis, Cody; Moody, Kristen

2014-01-01

There are no psychological characteristics or psychopathology separating terrorists from the general population. Rather, it is group dynamics, with a particular emphasis on collective identity, that helps to explain terrorist psychology. Just as there is a diverse spectrum of kinds of terrorism, so too is there a spectrum of terrorist psychologies. Some terrorists, those in nationalist-separatist groups, such as Fatah and the IRA, are continuing with the mission of their parents who are dissident to the regime. The opposite generational provenance is seen among social-revolutionary terrorists, such as the Weather Underground and the Red Army Faction in Germany, who are rebelling against their parents' generation, which is loyal to the regime. Four waves of terrorism can be distinguished: the "anarchist wave"; the "anti-colonial wave" (nationalist-separatist), with minority groups seeking to be liberated from their colonial masters or from the majority in their country; the "new left" wave (social-revolutionary); and now the "religious" wave. With the communications revolution, a new phenomenon is emerging which may presage a fifth wave: lone wolf terrorists who through the Internet are radicalized and feel they belong to the virtual community of hatred. A typology of lone wolf terrorism is proposed. Copyright © 2014 John Wiley & Sons, Ltd.

Connecting geoscience systems and data using Linked Open Data in the Web of Data

NASA Astrophysics Data System (ADS)

Ritschel, Bernd; Neher, Günther; Iyemori, Toshihiko; Koyama, Yukinobu; Yatagai, Akiyo; Murayama, Yasuhiro; Galkin, Ivan; King, Todd; Fung, Shing F.; Hughes, Steve; Habermann, Ted; Hapgood, Mike; Belehaki, Anna

2014-05-01

Linked Data or Linked Open Data (LOD) in the realm of free and publically accessible data is one of the most promising and most used semantic Web frameworks connecting various types of data and vocabularies including geoscience and related domains. The semantic Web extension to the commonly existing and used World Wide Web is based on the meaning of entities and relationships or in different words classes and properties used for data in a global data and information space, the Web of Data. LOD data is referenced and mash-uped by URIs and is retrievable using simple parameter controlled HTTP-requests leading to a result which is human-understandable or machine-readable. Furthermore the publishing and mash-up of data in the semantic Web realm is realized by specific Web standards, such as RDF, RDFS, OWL and SPARQL defined for the Web of Data. Semantic Web based mash-up is the Web method to aggregate and reuse various contents from different sources, such as e.g. using FOAF as a model and vocabulary for the description of persons and organizations -in our case- related to geoscience projects, instruments, observations, data and so on. On the example of three different geoscience data and information management systems, such as ESPAS, IUGONET and GFZ ISDC and the associated science data and related metadata or better called context data, the concept of the mash-up of systems and data using the semantic Web approach and the Linked Open Data framework is described in this publication. Because the three systems are based on different data models, data storage structures and technical implementations an extra semantic Web layer upon the existing interfaces is used for mash-up solutions. In order to satisfy the semantic Web standards, data transition processes, such as the transfer of content stored in relational databases or mapped in XML documents into SPARQL capable databases or endpoints using D2R or XSLT is necessary. In addition, the use of mapped and/or merged domain specific and cross-domain vocabularies in the sense of terminological ontologies are the foundation for a virtually unified data retrieval and access in IUGONET, ESPAS and GFZ ISDC data management systems. SPARQL endpoints realized either by originally RDF databases, e.g. Virtuoso or by virtual SPARQL endpoints, e.g. D2R services enable an only upon Web standard-based mash-up of domain-specific systems and data, such as in this case the space weather and geomagnetic domain but also cross-domain connection to data and vocabularies, e.g. related to NASA's VxOs, particularly VWO or NASA's PDS data system within LOD. LOD - Linked Open Data RDF - Resource Description Framework RDFS - RDF Schema OWL - Ontology Web Language SPARQL - SPARQL Protocol and RDF Query Language FOAF - Friends of a Friend ontology ESPAS - Near Earth Space Data Infrastructure for e-Science (Project) IUGONET - Inter-university Upper Atmosphere Global Observation Network (Project) GFZ ISDC - German Research Centre for Geosciences Information System and Data Center XML - Extensible Mark-up Language D2R - (Relational) Database to RDF (Transformation) XSLT - Extensible Stylesheet Language Transformation Virtuoso - OpenLink Virtuoso Universal Server (including RDF data management) NASA - National Aeronautics and Space Administration VOx - Virtual Observatories VWO - Virtual Wave Observatory PDS - Planetary Data System

Retrieval of Body-Wave Reflections Using Ambient Noise Interferometry Using a Small-Scale Experiment

NASA Astrophysics Data System (ADS)

Dantas, Odmaksuel Anísio Bezerra; do Nascimento, Aderson Farias; Schimmel, Martin

2018-02-01

We report the retrieval of body-wave reflections from noise records using a small-scale experiment over a mature oil field. The reflections are obtained by cross-correlation and stacking of the data. We used the stacked correlograms to create virtual source-to-receiver common shot gathers and are able to obtain body-wave reflections. Surface waves that obliterate the body-waves in our noise correlations were attenuated following a standard procedure from active source seismics. Further different strategies were employed to cross-correlate and stack the data: classical geometrical normalized cross-correlation (CCGN), phase cross-correlation (PCC), linear stacking**** and phase weighted stacking (PWS). PCC and PWS are based on the instantaneous phase coherence of analytic signals. The four approaches are independent and reveal the reflections; nevertheless, the combination of PWS and CCGN provided the best results. Our analysis is based on 2145 cross-correlations of 600 s data segments. We also compare the resulted virtual shot gathers with an active 2D seismic line near the passive experiment. It is shown that our ambient noise analysis reproduces reflections which are present in the active seismic data.

Propagating Waves Transverse to the Magnetic Field in a Solar Prominence

NASA Astrophysics Data System (ADS)

Kucera, Therese A.; Knizhnik, K.; Lopez Ariste, A.; Luna Bennasar, M.; Schmieder, B.; Toot, D.

2013-07-01

We have observed a quiescent prominence with the Hinode Solar Optical Telescope (SOT, in Ca II and H-alpha lines), Sacramento Peak Observatory (in H-alpha, H-beta and Sodium-D lines), and THEMIS/MTR (Télescope Héliographique pour l'Étude du Magnétisme et des Instabilités Solaires/MulTi Raies, providing vector magnetograms), and SDO/AIA (Solar Dynamics Observatory Atmospheric Imaging Assembly, in EUV) over a 4 hour period on 2012 October 10. The small fields of view of SOT, Sac Peak and THEMIS are centered on a large pillar-like prominence footpoint extending towards the surface. This feature appears in the larger field of view of the 304 Å band, as a large, quasi-vertical column with material flowing horizontally on each side. The THEMIS/MTR data indicate that the magnetic field in the pillar is essentially horizontal and the observations in the optical wavelengths show a large number of horizontally aligned features on a much smaller scale than the pillar as a whole. The data are consistent with a model of cool prominence plasma trapped in the dips of horizontal field lines. The SOT and Sac Peak data show what appear to be moving wave pulses. These pulses, which include a Doppler signature, move vertically, perpendicular to the field direction, along quasi-vertical columns. The pulses have a velocity of propagation of about 10 km/s, a period about 260 sec, and a wavelength around 2000 km. We interpret these waves in terms of fast magneto-sonic waves and discuss possible wave drivers.

A Roadmap to Fundamental Physics from LISA EMRI Observations

NASA Astrophysics Data System (ADS)

Sopuerta, Carlos F.

2010-09-01

The Laser Interferometer Space Antenna is a future space-based gravitational-wave observatory (a joint mission between the European Space Agency and the US National Aeronautics and Space Administration) that is expected to be launched during the next decade. It will operate in the low-frequency gravitational-wave band, probably the richest part of the gravitational-wave spectrum in terms of science potential, where we find: massive black hole mergers as the outcome of galaxy collisions; many galactic compact binaries; the capture and subsequent inspiral of a stellar compact object into a massive black hole; and gravitational-wave signatures from early universe physical processes connected to high-energy physics and physics not yet fully understood. In this article we focus on the third type of source, the so-called extreme-mass-ratio inspirals, a high precision tool for gravitational wave astronomy that can be used, among other things, to advance in our understanding of fundamental physics questions like the nature and structure of black holes and the details of the gravitational interaction in regimes not yet proven by other experiments/observatories. Here, we give an account of some of the progress made in the development of tools to exploit the future LISA EMRI observations, we discuss what scientific questions we can try to answer from this information and, finally, we discuss the main theoretical challenges that we face in order to develop all the necessary tools to maximize the scientific outcome and some avenues that can be followed to make progress in the near future.

Automated telescope scheduling

NASA Technical Reports Server (NTRS)

Johnston, Mark D.

1988-01-01

With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

Seismic Interferometry of Cultural Noise: Body Waves Extracted from Auto and Train Traffic

NASA Astrophysics Data System (ADS)

Quiros, D. A.; Brown, L. D.; Kim, D.

2014-12-01

Here we report results of two experiments designed to evaluate the utility of anthropogenic noise as a source for generating body waves via interferometry. In particular we address the suggestion that traffic noise might prove effective at producing P and S waves at frequencies and amplitudes appropriate for crustal scale refraction and reflection imaging. The first experiment recorded routine traffic for about 10 days along a straight stretch of a rural highway between the towns of Elmira and Ithaca in upstate New York. The array was deployed along the highway using two different spacings: an inner segment with Δx ~ 25 m, bracketed between flanking segments with Δx ~ 100 m. In addition to strong surface waves, direct and reflected P waves were clearly apparent on most of the virtual shot gathers. These P-waves match the velocities of P-waves recorded from a conventional, small scale refraction survey carried out at the same site with a shotgun source and an engineering seismograph. The second experiment was located in the Rio Grande rift near Belen New Mexico, where relatively isolated train traffic was recorded for about 6 days parallel to a busy section of the BNRF railway that bisects New Mexico. Interferometric processing of the data produced virtual shot gathers with strong surface waves, as expected, but also linear arrivals that exhibit apparent velocities similar to those reported for the shallow Tertiary-Quaternary alluvium based on the original COCORP vibroseis surveys nearby. However the virtual shot gathers derived from the train sources are more complex that those obtained from the auto noise, which we suspect is due to the extended length of the train source relative to the spread length. Both experiments confirm that cultural noise can be used for subsurface imaging, though the cost effectiveness of this approach depends, among other factors, upon the total length of recording time needed to probe to depths of interest. They are both sources that clearly lend themselves to exploitation by the new generation of large N array technologies.

COMMITTEES: Proceedings of the 13th Gravitational Waves Data Analysis Workshop (GWDAW13), San Juan, Puerto Rico, 19-22 January 2009 Proceedings of the 13th Gravitational Waves Data Analysis Workshop (GWDAW13), San Juan, Puerto Rico, 19-22 January 2009

NASA Astrophysics Data System (ADS)

2009-10-01

Science Organising Committee (SOC) Bruce Allen, AEI, Germany Patrick Brady, University of Wisconsin Milwaukee, USA Deepto Chakrabarty, MIT, USA Eugenio Coccia, INFN, Gran Sasso, Italy James Cordes, Cornell University, USA Mario Díaz (Chair), University of Texas Brownsville, USA Sam Finn, Penn State, USA Neil Gehrels, NASA GSFC, USA Fredrick A Jenet, University of Texas Brownsville, USA Nobuyuki Kanda, Osaka City University, Japan Erik Katsavounides, MIT, USA Dick Manchester, ATNF, Australia Soumya Mohanty, University of Texas Brownsville, USA Benoit Mours, LAPP-Annecy, France Maria Alessandra Papa, AEI, Germany Kate Scholberg, Duke University, USA Susan Scott, The Australian National University Alberto Vecchio, University of Birmingham, UK Andrea Vicere, INFN - Sezione di Firenze, Italy Stan Whitcomb, LIGO CALTECH, USA Local Organising Committee (LOC) Paulo Freire (Arecibo Observatory, Puerto Rico) Murray Lewis (Arecibo Observatory, Puerto Rico) Wanda Wiley (University of Texas Brownsville, USA)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giudice, Gian F.; McCullough, Matthew; Urbano, Alfredo

The LIGO observation of gravitational waves from a binary black hole merger has begun a new era in fundamental physics. If new dark sector particles, be they bosons or fermions, can coalesce into exotic compact objects (ECOs) of astronomical size, then the first evidence for such objects, and their underlying microphysical description, may arise in gravitational wave observations. In this work we study how the macroscopic properties of ECOs are related to their microscopic properties, such as dark particle mass and couplings. We then demonstrate the smoking gun exotic signatures that would provide observational evidence for ECOs, and hence newmore » particles, in terrestrial gravitational wave observatories. Finally, we discuss how gravitational waves can test a core concept in general relativity: Hawking’s area theorem.« less

Gravitational Waves from Gravitational Collapse.

PubMed

Fryer, Chris L; New, Kimberly C B

2011-01-01

Gravitational-wave emission from stellar collapse has been studied for nearly four decades. Current state-of-the-art numerical investigations of collapse include those that use progenitors with more realistic angular momentum profiles, properly treat microphysics issues, account for general relativity, and examine non-axisymmetric effects in three dimensions. Such simulations predict that gravitational waves from various phenomena associated with gravitational collapse could be detectable with ground-based and space-based interferometric observatories. This review covers the entire range of stellar collapse sources of gravitational waves: from the accretion-induced collapse of a white dwarf through the collapse down to neutron stars or black holes of massive stars to the collapse of supermassive stars. Supplementary material is available for this article at 10.12942/lrr-2011-1.

Virtual detector theory for strong-field atomic ionization

NASA Astrophysics Data System (ADS)

Wang, Xu; Tian, Justin; Eberly, J. H.

2018-04-01

A virtual detector (VD) is an imaginary device located at a fixed position in space that extracts information from the wave packet passing through it. By recording the particle momentum and the corresponding probability current at each time, the VDs can accumulate and build the differential momentum distribution of the particle, in a way that resembles real experiments. A mathematical proof is given for the equivalence of the differential momentum distribution obtained by the VD method and by Fourier transforming the wave function. In addition to being a tool for reducing the computational load, VDs have also been found useful in interpreting the ultrafast strong-field ionization process, especially the controversial quantum tunneling process.

Alfvén Waves in the Solar Corona

NASA Astrophysics Data System (ADS)

Tomczyk, S.; McIntosh, S. W.; Keil, S. L.; Judge, P. G.; Schad, T.; Seeley, D. H.; Edmondson, J.

2007-08-01

Alfvén waves, transverse incompressible magnetic oscillations, have been proposed as a possible mechanism to heat the Sun’s corona to millions of degrees by transporting convective energy from the photosphere into the diffuse corona. We report the detection of Alfvén waves in intensity, line-of-sight velocity, and linear polarization images of the solar corona taken using the FeXIII 1074.7-nanometer coronal emission line with the Coronal Multi-Channel Polarimeter (CoMP) instrument at the National Solar Observatory, New Mexico. Ubiquitous upward propagating waves were seen, with phase speeds of 1 to 4 megameters per second and trajectories consistent with the direction of the magnetic field inferred from the linear polarization measurements. An estimate of the energy carried by the waves that we spatially resolved indicates that they are too weak to heat the solar corona; however, unresolved Alfvén waves may carry sufficient energy.

Search for Transient Gravitational Waves in Coincidence with Short-Duration Radio Transients During 2007-2013

NASA Technical Reports Server (NTRS)

Abbott, B. P.; Hughey, Brennan; Zanolin, Michele; Szczepanczyk, Marek; Gill, Kiranjyot; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.;

Searching for photon-sector Lorentz violation using gravitational-wave detectors

NASA Astrophysics Data System (ADS)

Kostelecký, V. Alan; Melissinos, Adrian C.; Mewes, Matthew

2016-10-01

We study the prospects for using interferometers in gravitational-wave detectors as tools to search for photon-sector violations of Lorentz symmetry. Existing interferometers are shown to be exquisitely sensitive to tiny changes in the effective refractive index of light occurring at frequencies around and below the microhertz range, including at the harmonics of the frequencies of the Earth's sidereal rotation and annual revolution relevant for tests of Lorentz symmetry. We use preliminary data obtained by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2006-2007 to place constraints on coefficients for Lorentz violation in the photon sector exceeding current limits by about four orders of magnitude.

Space-Based Gravitational-wave Mission Concept Studies

NASA Technical Reports Server (NTRS)

Livas, Jeffrey C.

2012-01-01

The LISA Mission Concept has been under study for over two decades as a spacebased gravitational-wave detector capable of observing astrophysical sources in the 0.0001 to 1 Hz band. The concept has consistently received strong recommendations from various review panels based on the expected science, most recently from the US Astr02010 Decadal Review. Budget constraints have led both the US and European Space agencies to search for lower cost options. We report results from the US effort to explore the tradeoffs between mission cost and science return, and in particular a family of mission concepts referred to as SGO (Space-based Gravitational-wave Observatory).

Classical black holes: the nonlinear dynamics of curved spacetime.

PubMed

Thorne, Kip S

2012-08-03

Numerical simulations have revealed two types of physical structures, made from curved spacetime, that are attached to black holes: tendexes, which stretch or squeeze anything they encounter, and vortexes, which twist adjacent inertial frames relative to each other. When black holes collide, their tendexes and vortexes interact and oscillate (a form of nonlinear dynamics of curved spacetime). These oscillations generate gravitational waves, which can give kicks up to 4000 kilometers per second to the merged black hole. The gravitational waves encode details of the spacetime dynamics and will soon be observed and studied by the Laser Interferometer Gravitational Wave Observatory and its international partners.

Classical Black Holes: The Nonlinear Dynamics of Curved Spacetime

NASA Astrophysics Data System (ADS)

Thorne, Kip S.

2012-08-01

Numerical simulations have revealed two types of physical structures, made from curved spacetime, that are attached to black holes: tendexes, which stretch or squeeze anything they encounter, and vortexes, which twist adjacent inertial frames relative to each other. When black holes collide, their tendexes and vortexes interact and oscillate (a form of nonlinear dynamics of curved spacetime). These oscillations generate gravitational waves, which can give kicks up to 4000 kilometers per second to the merged black hole. The gravitational waves encode details of the spacetime dynamics and will soon be observed and studied by the Laser Interferometer Gravitational Wave Observatory and its international partners.

Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms

NASA Astrophysics Data System (ADS)

2004-06-01

Astronomers studying gas clouds in the famous Whirlpool Galaxy have found important clues supporting a theory that seeks to explain how the spectacular spiral arms of galaxies can persist for billions of years. The astronomers applied techniques used to study similar gas clouds in our own Milky Way to those in the spiral arms of a neighbor galaxy for the first time, and their results bolster a theory first proposed in 1964. M51 The spiral galaxy M51: Left, as seen with the Hubble Space Telescope; Right, radio image showing location of Carbon Monoxide gas. CREDIT: STScI, OVRO, IRAM (Click on image for larger version) Image Files Optical and Radio (CO) Views (above image) HST Optical Image with CO Contours Overlaid Radio/Optical Composite Image of M51 VLA/Effelsberg Radio Image of M51, With Panel Showing Magnetic Field Lines The Whirlpool Galaxy, about 31 million light-years distant, is a beautiful spiral in the constellation Canes Venatici. Also known as M51, it is seen nearly face-on from Earth and is familiar to amateur astronomers and has been featured in countless posters, books and magazine articles. "This galaxy made a great target for our study of spiral arms and how star formation works along them," said Eva Schinnerer, of the National Radio Astronomy Observatory in Socorro, NM. "It was ideal for us because it's one of the closest face-on spirals in the sky," she added. Schinnerer worked with Axel Weiss of the Institute for Millimeter Radio Astronomy (IRAM) in Spain, Susanne Aalto of the Onsala Space Observatory in Sweden, and Nick Scoville of Caltech. The astronomers presented their findings to the American Astronomical Society's meeting in Denver, Colorado. The scientists analyzed radio emission from Carbon Monoxide (CO) molecules in giant gas clouds along M51's spiral arms. Using telescopes at Caltech's Owens Valley Radio Observatory and the 30-meter radio telescope of IRAM, they were able to determine the temperatures and amounts of turbulence within the clouds. Their results provide strong support for a theory that "density waves" explain how spiral arms can persist in a galaxy without winding themselves so tightly that, in effect, they disappear. The density-wave theory, proposed by Frank Shu and C.C. Lin in 1964, says that a galaxy's spiral pattern is a wave of higher density, or compression, that revolves around the galaxy at a speed different from that of the galaxy's gas and stars. Schinnerer and her colleagues studied a region in one of M51's spiral arms that presumably has just overtaken and passed through the density wave. Their data indicate that gas on the trailing edge of the spiral arm, which has most recently passed through the density wave, is both warmer and more turbulent than gas in the forward edge of the arm, which would have passed through the density wave longer ago. "This is what we would expect from the density-wave theory," Schinnerer said. "The gas that passed through the density wave earlier has had time to cool and lose the turbulence caused by the passage," she added. "Our results show, for the first time, how the density wave operates on a cloud-cloud scale, and how it promotes and prevents star formation in spiral arms," Aalto said. The next step, the scientists say, is to look at other spiral galaxies to see if a similar pattern is present. That will have to wait, Schinnerer said, because the radio emission from CO molecules that provides the information on temperature and turbulence is very faint. "When the Atacama Large Millimeter Array (ALMA) comes on line, it will have the ability to extend this type of study to other galaxies. We look forward to using ALMA to test the density-wave model more thoroughly," Schinnerer said. ALMA is a millimeter-wave observatory that will use 64, 12-meter-diameter dish antennas on the Atacama Desert of northern Chile. Now under construction, ALMA will provide astronomers with an unprecedented capability to study the Universe at millimeter wavelengths. The Whirlpool Galaxy was discovered by the French comet-hunter Charles Messier on October 13, 1773. He included it as object number 51 in his now-famous catalog of astronomical objects that, in a small telescope, might be mistaken for a comet. In 1845, the British astronomer Lord Rosse discovered the spiral structure in the galaxy. For amateur astronomers using telescopes in dark-sky locations, M51 is a showpiece object. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

AstroCloud, a Cyber-Infrastructure for Astronomy Research: Cloud Computing Environments

NASA Astrophysics Data System (ADS)

Li, C.; Wang, J.; Cui, C.; He, B.; Fan, D.; Yang, Y.; Chen, J.; Zhang, H.; Yu, C.; Xiao, J.; Wang, C.; Cao, Z.; Fan, Y.; Hong, Z.; Li, S.; Mi, L.; Wan, W.; Wang, J.; Yin, S.

2015-09-01

AstroCloud is a cyber-Infrastructure for Astronomy Research initiated by Chinese Virtual Observatory (China-VO) under funding support from NDRC (National Development and Reform commission) and CAS (Chinese Academy of Sciences). Based on CloudStack, an open source software, we set up the cloud computing environment for AstroCloud Project. It consists of five distributed nodes across the mainland of China. Users can use and analysis data in this cloud computing environment. Based on GlusterFS, we built a scalable cloud storage system. Each user has a private space, which can be shared among different virtual machines and desktop systems. With this environments, astronomer can access to astronomical data collected by different telescopes and data centers easily, and data producers can archive their datasets safely.

Tools for Virtual Collaboration Designed for High Resolution Hydrologic Research with Continental-Scale Data Support

NASA Astrophysics Data System (ADS)

Duffy, Christopher; Leonard, Lorne; Shi, Yuning; Bhatt, Gopal; Hanson, Paul; Gil, Yolanda; Yu, Xuan

2015-04-01

Using a series of recent examples and papers we explore some progress and potential for virtual (cyber-) collaboration inspired by access to high resolution, harmonized public-sector data at continental scales [1]. The first example describes 7 meso-scale catchments in Pennsylvania, USA where the watershed is forced by climate reanalysis and IPCC future climate scenarios (Intergovernmental Panel on Climate Change). We show how existing public-sector data and community models are currently able to resolve fine-scale eco-hydrologic processes regarding wetland response to climate change [2]. The results reveal that regional climate change is only part of the story, with large variations in flood and drought response associated with differences in terrain, physiography, landuse and/or hydrogeology. The importance of community-driven virtual testbeds are demonstrated in the context of Critical Zone Observatories, where earth scientists from around the world are organizing hydro-geophysical data and model results to explore new processes that couple hydrologic models with land-atmosphere interaction, biogeochemical weathering, carbon-nitrogen cycle, landscape evolution and ecosystem services [3][4]. Critical Zone cyber-research demonstrates how data-driven model development requires a flexible computational structure where process modules are relatively easy to incorporate and where new data structures can be implemented [5]. From the perspective of "Big-Data" the paper points out that extrapolating results from virtual observatories to catchments at continental scales, will require centralized or cloud-based cyberinfrastructure as a necessary condition for effectively sharing petabytes of data and model results [6]. Finally we outline how innovative cyber-science is supporting earth-science learning, sharing and exploration through the use of on-line tools where hydrologists and limnologists are sharing data and models for simulating the coupled impacts of catchment hydrology on lake eco-hydrology (NSF-INSPIRE, IIS1344272). The research attempts to use a virtual environment (www.organicdatascience.org) to break down disciplinary barriers and support emergent communities of science. [1] Source: Leonard and Duffy, 2013, Environmental Modelling & Software; [2] Source: Yu et al, 2014, Computers in Geoscience; [3] Source: Duffy et al, 2014, Procedia Earth and Planetary Science; [4] Source: Shi et al, Journal of Hydrometeorology, 2014; [5] Source: Bhatt et al, 2014, Environmental Modelling & Software ; [6] Leonard and Duffy, 2014, Environmental Modelling and Software.

Space Science

NASA Image and Video Library

2004-10-07

Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, best known as the discoverer of the laws of planetary motion, were startled by the sudden appearance of a new star in the western sky, rivaling the brilliance of the nearby planets. Modern astronomers, using NASA's three orbiting Great Observatories, are unraveling the mysteries of the expanding remains of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy. When a new star appeared Oct. 9, 1604, observers could use only their eyes to study it. The telescope would not be invented for another four years. A team of modern astronomers has the combined abilities of NASA's Great Observatories, the Spritzer Space Telescope (SST), Hubble Space Telescope (HST), and Chandra X-Ray Observatory (CXO), to analyze the remains in infrared radiation, visible light, and X-rays. Visible-light images from Hubble's Advanced Camera for Surveys reveal where the supernova shock wave is slamming into the densest regions of surrounding gas. The astronomers used the SST to probe for material that radiates in infrared light, which shows heated microscopic dust particles that have been swept up by the supernova shock wave. The CXO data show regions of very hot gas. The combined image unveils a bubble-shaped shroud of gas and dust, 14 light-years wide and expanding at 4 million mph. There have been six known supernovas in our Milky Way over the past 1,000 years. Kepler's is the only one in which astronomers do not know what type of star exploded. By combining information from all three Great Observatories, astronomers may find the clues they need. Project management for both the HST and CXO programs is the responsibility of NASA’s Marshall Space Flight Center in Huntsville, Alabama.

Natural and anthropogenic ocean noise recorded at long-term and temporary observatories

NASA Astrophysics Data System (ADS)

Grevemeyer, Ingo; Metz, Dirk; Watts, Anthony B.; Geissler, Wolfram

2017-04-01

Most people worldwide would assume that the oceans are silent. However, a number of natural phenomenon's like ocean waves, wind, lightening, ice noise, earthquakes, and submarine volcanic activity contributes to the ambient ocean noise. During their evolution, marine animals like fish and mammals have adopted in many ways to the acoustic properties of the sea. Yet in recent decades, anthropogenic and hence manmade ocean noise level has risen profoundly. Due to extreme reliance of fish and mammals on underwater sounds for basic life functions, including searching for food or mate and the absence of any mechanism to safeguard them against it, underwater noise pollution may disrupt marine life. The primary sources of low-frequency anthropogenic noise include sounds associated with shipping, military operations, oil and gas exploration and production, and even research activities. Some scientists suggest that today virtually no marine environment is without any noise pollution. Thus, all marine life forms that rely heavily on the integrity of their acoustic habitat may have to adapt to new conditions. Of greatest concern for whales are low-frequency sounds that travel long distances in the ocean. Ship propellers and motors, for instance, produce sound at low frequencies, as do natural and manmade seismic activity. These profound, loud noises reverberate in the deep ocean and can effectively mask or block vital whale communication. However, in general very little is known about the world-wide distribution of ambient ocean noise. Thus, on a global scale and considering the vast areas of the world's oceans, we know virtually nothing about noise levels in different parts of the oceans and how anthropogenic noise contributes to ambient noise. Here, we use hydrophone recordings from the UN's Comprehensive Nuclear-Test-Ban Treaty organization (CTBTO) and ocean-bottom seismometers to provide an assessment of noise in all major basins, including the Pacific, Atlantic and Indian Ocean at low frequencies of <50 Hz. Hydrophones recorded explosive volcanic eruptions, calls of Fin whales, distant seismic surveys and ship's traffic. Silent setting are characterized at 10 to 50 Hz by a noise level of 50 to 70 dB while areas affected by heavy shipping show noise levels of >100 dB. At frequencies below 1 Hz the ambient noise field is dominated by microseisms, forces by ocean gravity waves and surf.

Digital ionosonde studies of F-region waves. [measuring ionospheric disturbances

NASA Technical Reports Server (NTRS)

Harper, R. M.; Bowhill, S. A.

1974-01-01

Accurate fixed-frequency virtual height data collected on a digital ionosonde are analyzed to measure speed and direction of traveling ionospheric disturbances by matching the experimental data with virtual height and echo amplitude obtained from a simple model of the disturbed ionosphere. Several data records analyzed in this manner indicate speeds of 400 to 680 m/sec and a direction of propagation from north to south. The digital ionosonde collects virtual height data with a time resolution of 10 sec and a height resolution of less than 300 m.

Comparing numerical and analytic approximate gravitational waveforms

NASA Astrophysics Data System (ADS)

Afshari, Nousha; Lovelace, Geoffrey; SXS Collaboration

2016-03-01

A direct observation of gravitational waves will test Einstein's theory of general relativity under the most extreme conditions. The Laser Interferometer Gravitational-Wave Observatory, or LIGO, began searching for gravitational waves in September 2015 with three times the sensitivity of initial LIGO. To help Advanced LIGO detect as many gravitational waves as possible, a major research effort is underway to accurately predict the expected waves. In this poster, I will explore how the gravitational waveform produced by a long binary-black-hole inspiral, merger, and ringdown is affected by how fast the larger black hole spins. In particular, I will present results from simulations of merging black holes, completed using the Spectral Einstein Code (black-holes.org/SpEC.html), including some new, long simulations designed to mimic black hole-neutron star mergers. I will present comparisons of the numerical waveforms with analytic approximations.

High Energy Follow-up Study of Gravitational Wave Transients

NASA Astrophysics Data System (ADS)

Barker, Brandon L.; Patricelli, Barbara

2018-01-01

As second-generation gravitational wave interferometers, such as Advanced Virgo and Advanced LIGO, reach their design sensitivities, a new lens into our universe will become available. Many of the most violent and energetic events in the cosmos, in particular the merger of compact objects and core collapse supernovae, are sources of gravitational waves and are also believed to be connected with Gamma Ray Bursts. Joint observations of electromagnetic and gravitational wave signals will provide an ideal opportunity to study the physics of these transient events and their progenitors. In particular, gamma ray observatories such as Fermi, coupled with precise sky lo- calization, will be crucial to observe the high energy electromagnetic counterparts to gravitational wave signals. We constructed joint binary neutron star and gamma ray burst detection rate estimates using an analysis pipeline and report on the results of this analysis.

Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube

NASA Astrophysics Data System (ADS)

Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bourret, S.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coelho, J. A. B.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; de Bonis, G.; Distefano, C.; di Palma, I.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Giordano, V.; Glotin, H.; Grégoire, T.; Gracia Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Lotze, M.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Mele, R.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Nezri, E.; Pǎvǎlaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Quinn, L.; Racca, C.; Riccobene, G.; Sánchez-Losa, A.; Saldaña, M.; Salvadori, I.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schüssler, F.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Taiuti, M.; Tayalati, Y.; Trovato, A.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; van Elewyck, V.; Versari, F.; Vivolo, D.; Vizzoca, A.; Wilms, J.; Zornoza, J. D.; Zúñiga, J.; Aartsen, M. G.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Ahrens, M.; Al Samarai, I.; Altmann, D.; Andeen, K.; Anderson, T.; Ansseau, I.; Anton, G.; Archinger, M.; Argüelles, C.; Auffenberg, J.; Axani, S.; Bagherpour, H.; Bai, X.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; Benzvi, S.; Berley, D.; Bernardini, E.; Besson, D. Z.; Binder, G.; Bindig, D.; Blaufuss, E.; Blot, S.; Bohm, C.; Börner, M.; Bos, F.; Bose, D.; Böser, S.; Botner, O.; Bradascio, F.; Braun, J.; Brayeur, L.; Bretz, H.-P.; Bron, S.; Burgman, A.; Carver, T.; Casier, M.; Cheung, E.; Chirkin, D.; Christov, A.; Clark, K.; Classen, L.; Coenders, S.; Collin, G. H.; Conrad, J. M.; Cowen, D. F.; Cross, R.; Day, M.; de André, J. P. A. M.; de Clercq, C.; Del Pino Rosendo, E.; Dembinski, H.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de Wasseige, G.; de With, M.; Deyoung, T.; Díaz-Vélez, J. C.; di Lorenzo, V.; Dujmovic, H.; Dumm, J. P.; Dunkman, M.; Eberhardt, B.; Ehrhardt, T.; Eichmann, B.; Eller, P.; Euler, S.; Evenson, P. A.; Fahey, S.; Fazely, A. R.; Feintzeig, J.; Felde, J.; Filimonov, K.; Finley, C.; Flis, S.; Fösig, C.-C.; Franckowiak, A.; Friedman, E.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Ghorbani, K.; Giang, W.; Gladstone, L.; Glauch, T.; Glüsenkamp, T.; Goldschmidt, A.; Gonzalez, J. G.; Grant, D.; Griffith, Z.; Haack, C.; Hallgren, A.; Halzen, F.; Hansen, E.; Hansmann, T.; Hanson, K.; Hebecker, D.; Heereman, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hignight, J.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Hoshina, K.; Huang, F.; Huber, M.; Hultqvist, K.; in, S.; Ishihara, A.; Jacobi, E.; Japaridze, G. S.; Jeong, M.; Jero, K.; Jones, B. J. P.; Kang, W.; Kappes, A.; Karg, T.; Karle, A.; Katz, U.; Kauer, M.; Keivani, A.; Kelley, J. L.; Kheirandish, A.; Kim, J.; Kim, M.; Kintscher, T.; Kiryluk, J.; Kittler, T.; Klein, S. R.; Kohnen, G.; Koirala, R.; Kolanoski, H.; Konietz, R.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. 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V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. 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S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Rhoades, E.; Ricci, F.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sandberg, V.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheuer, J.; Schmidt, E.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Setyawati, Y.; Shaddock, D. A.; Shaffer, T. J.; Shahriar, M. S.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, J. R.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stevenson, S. P.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Taracchini, A.; Taylor, R.; Theeg, T.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tippens, T.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tomlinson, C.; Tonelli, M.; Tornasi, Z.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tse, M.; Tso, R.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; van den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Varma, V.; Vass, S.; Vasúth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Viceré, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Whittle, C.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Worden, J.; Wright, J. L.; Wu, D. S.; Wu, G.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, Hang; Yu, Haocun; Yvert, M.; Zadrożny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S. J.; Zhu, X. J.; Zucker, M. E.; Zweizig, J.; ANTARES Collaboration

2017-07-01

The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find two and four neutrino candidates detected by IceCube, and one and zero detected by Antares, within ±500 s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use nondetection to constrain isotropic-equivalent high-energy neutrino emission from GW151226, adopting the GW event's 3D localization, to less than 2 ×1 051- 2 ×1 054 erg .

Observatories on the moon

NASA Astrophysics Data System (ADS)

Burns, J. O.; Duric, N.; Taylor, G. J.; Johnson, S. W.

1990-03-01

It is suggested that the moon could be a haven for astronomy with observatories on its surface yielding extraordinarily detailed views of the heavens and open new windows to study the universe. The near absence of an atmosphere, the seismic stability of its surface, the low levels of interference from light and radio waves and the abundance of raw materials make the moon an ideal site for constructing advanced astronomical observatories. Due to increased interest in the U.S. in the moon as a scientific platform, planning has begun for a permanent lunar base and for astronomical observatories that might be built on the moon in the 21st century. Three specific projects are discussed: (1) the Very Low Frequency Array (VLFA), which would consist of about 200 dipole antennas, each resembling a TV reception antenna about one meter in length; (2) the Lunar Optical-UV-IR Synthesis Array (LOUISA), which will improve on the resolution of the largest ground-based telescope by a factor of 100,000; and (3) a moon-earth radio interferometer, which would have a resolution of about one-hundredth-thousandth of an arc second at a frequency of 10 GHz.

Achievements of the Armenian Astronomy and the Present Activities of the Armenian Astronomical Society

NASA Astrophysics Data System (ADS)

Mickaelian, A. M.

2014-10-01

A report is given on the achievements of the Armenian astronomy during the last years and on the present activities of the Armenian Astronomical Society (ArAS). ArAS membership, ArAS electronic newsletters (ArASNews), ArAS webpage, international collaboration, Armenian Virtual Observatory (ArVO), membership in international organizations, grants, prizes, meetings, summer schools, astronomical Olympiads, other matters related to astronomical education, archaeoastronomy, astronomy outreach and ArAS further projects are discussed.

Bode's Astronomisches Jahrbuch as an international archive journal. (German Title: Bodes Astronomisches Jahrbuch als internationales Archivjournal)

NASA Astrophysics Data System (ADS)

Kokott, Wolfgang

The Astronomisches Jahrbuch, published from 1776 onwards by the Royal Academy of Sciences at Berlin, was to include ``a collection of the most recent observations, news, remarks and contributions''. Established by J.H. Lambert and edited for five decades by J.E. Bode, this almanac became from the start a high ranking international publication, with Bode's modest Berlin Observatory serving as a clearinghouse of information originating from virtually all European countries.

New NED XML/VOtable Services and Client Interface Applications

NASA Astrophysics Data System (ADS)

Pevunova, O.; Good, J.; Mazzarella, J.; Berriman, G. B.; Madore, B.

2005-12-01

The NASA/IPAC Extragalactic Database (NED) provides data and cross-identifications for over 7 million extragalactic objects fused from thousands of survey catalogs and journal articles. The data cover all frequencies from radio through gamma rays and include positions, redshifts, photometry and spectral energy distributions (SEDs), sizes, and images. NED services have traditionally supplied data in HTML format for connections from Web browsers, and a custom ASCII data structure for connections by remote computer programs written in the C programming language. We describe new services that provide responses from NED queries in XML documents compliant with the international virtual observatory VOtable protocol. The XML/VOtable services support cone searches, all-sky searches based on object attributes (survey names, cross-IDs, redshifts, flux densities), and requests for detailed object data. Initial services have been inserted into the NVO registry, and others will follow soon. The first client application is a Style Sheet specification for rendering NED VOtable query results in Web browsers that support XML. The second prototype application is a Java applet that allows users to compare multiple SEDs. The new XML/VOtable output mode will also simplify the integration of data from NED into visualization and analysis packages, software agents, and other virtual observatory applications. We show an example SED from NED plotted using VOPlot. The NED website is: http://nedwww.ipac.caltech.edu.

Virtual Global Magnetic Observatory - Concept and Implementation

NASA Astrophysics Data System (ADS)

Papitashvili, V.; Clauer, R.; Petrov, V.; Saxena, A.

2002-12-01

The existing World Data Centers (WDC) continue to serve excellently the worldwide scientific community in providing free access to a huge number of global geophysical databases. Various institutions at different geographic locations house these Centers, mainly organized by a scientific discipline. However, population of the Centers requires mandatory or voluntary submission of locally collected data. Recently many digital geomagnetic datasets have been placed on the World Wide Web and some of these sets have not been even submitted to any data center. This has created an urgent need for more sophisticated search engines capable of identifying geomagnetic data on the Web and then retrieving a certain amount of data for the scientific analysis. In this study, we formulate a concept of the virtual global magnetic observatory (VGMO) that currently uses a pre-set list of the Web-based geomagnetic data holders (including WDC) as retrieving a requested case-study interval. Saving the retrieved data locally over the multiple requests, a VGMO user begins to build his/her own data sub-center, which does not need to search the Web if the newly requested interval will be within a span of the earlier retrieved data. At the same time, this self-populated sub-center becomes available to other VGMO users down on the requests chain. Some aspects of the Web``crawling'' helping to identify the newly ``webbed'' digital geomagnetic data are also considered.

Virtual Observatory Interfaces to the Chandra Data Archive

NASA Astrophysics Data System (ADS)

Tibbetts, M.; Harbo, P.; Van Stone, D.; Zografou, P.

2014-05-01

The Chandra Data Archive (CDA) plays a central role in the operation of the Chandra X-ray Center (CXC) by providing access to Chandra data. Proprietary interfaces have been the backbone of the CDA throughout the Chandra mission. While these interfaces continue to provide the depth and breadth of mission specific access Chandra users expect, the CXC has been adding Virtual Observatory (VO) interfaces to the Chandra proposal catalog and observation catalog. VO interfaces provide standards-based access to Chandra data through simple positional queries or more complex queries using the Astronomical Data Query Language. Recent development at the CDA has generalized our existing VO services to create a suite of services that can be configured to provide VO interfaces to any dataset. This approach uses a thin web service layer for the individual VO interfaces, a middle-tier query component which is shared among the VO interfaces for parsing, scheduling, and executing queries, and existing web services for file and data access. The CXC VO services provide Simple Cone Search (SCS), Simple Image Access (SIA), and Table Access Protocol (TAP) implementations for both the Chandra proposal and observation catalogs within the existing archive architecture. Our work with the Chandra proposal and observation catalogs, as well as additional datasets beyond the CDA, illustrates how we can provide configurable VO services to extend core archive functionality.

Prediction of transits of Solar system objects in Kepler/K2 images: an extension of the Virtual Observatory service SkyBoT

NASA Astrophysics Data System (ADS)

Berthier, J.; Carry, B.; Vachier, F.; Eggl, S.; Santerne, A.

2016-05-01

All the fields of the extended space mission Kepler/K2 are located within the ecliptic. Many Solar system objects thus cross the K2 stellar masks on a regular basis. We aim at providing to the entire community a simple tool to search and identify Solar system objects serendipitously observed by Kepler. The sky body tracker (SkyBoT) service hosted at Institut de mécanique céleste et de calcul des éphémérides provides a Virtual Observatory compliant cone search that lists all Solar system objects present within a field of view at a given epoch. To generate such a list in a timely manner, ephemerides are pre-computed, updated weekly, and stored in a relational data base to ensure a fast access. The SkyBoT web service can now be used with Kepler. Solar system objects within a small (few arcminutes) field of view are identified and listed in less than 10 s. Generating object data for the entire K2 field of view (14°) takes about a minute. This extension of the SkyBoT service opens new possibilities with respect to mining K2 data for Solar system science, as well as removing Solar system objects from stellar photometric time series.

VOClient: Application Integration in the Virtual Observatory

NASA Astrophysics Data System (ADS)

Fitzpatrick, Michael J.; Tody, D.

2007-12-01

We present VOClient, a new software package that provides a high-level, easy-to-use, programmable interface between desktop applications and the distributed VO framework, providing access to remote VO data and services, reference implementations for VO data-providers and end-user applications. Applications have traditionally been written to deal directly with local images, catalogs or spectra; VOClient allows these applications to use remote VO data and services without requiring a developer to know the details of the underlying and evolving VO technologies. The programmable interface provides equivalent functionality for a wide variety of both legacy and modern development languages and environments and can be easily extended to add new functionality. The server component of the project provides a reference implementation and toolkit which can be used to build VO data services, and the commandline tools provide ready-to-use applications to access VO data and services from the desktop or scripting environment. The use of VOClient to integrate VO technologies with legacy systems such as IRAF is examined as a case-study, and the use of these techniques in other environments, especially their applicability to legacy code and systems, is also discussed. VOClient is meant both for the astronomer wishing to revive an old and trusted task with new VO capabiities, as well as the institutional project providing data or services to the Virtual Observatory.

Ultrahigh energy neutrino afterglows of nearby long duration gamma-ray bursts

NASA Astrophysics Data System (ADS)

Thomas, Jessymol K.; Moharana, Reetanjali; Razzaque, Soebur

2017-11-01

Detection of ultrahigh energy (UHE, ≳1 PeV ) neutrinos from astrophysical sources will be a major advancement in identifying and understanding the sources of UHE cosmic rays (CRs) in nature. Long duration gamma-ray burst (GRB) blast waves have been considered as potential acceleration sites of UHECRs. These CRs are expected to interact with GRB afterglow photons, which are synchrotron radiation from relativistic electrons coaccelerated with CRs in the blast wave, and naturally produce UHE neutrinos. Fluxes of these neutrinos are uncertain, however, and crucially depend on the observed afterglow modeling. We have selected a sample of 23 long duration GRBs within redshift 0.5 for which adequate electromagnetic afterglow data are available and which could produce high flux of UHE afterglow neutrinos, being nearby. We fit optical, x-ray, and γ -ray afterglow data with an adiabatic blast wave model in a constant density interstellar medium and in a wind environment where the density of the wind decreases as the inverse square of the radius from the center of the GRB. The blast wave model parameters extracted from these fits are then used for calculating UHECR acceleration and p γ interactions to produce UHE neutrino fluxes from these GRBs. We have also explored the detectability of these neutrinos by currently running and upcoming large area neutrino detectors, such as the Pierre Auger Observatory, IceCube Gen-2, and KM3NeT observatories. We find that our realistic flux models from nearby GRBs will be unconstrained in the foreseeable future.

Laser Interferometry for Gravitational Wave Observation: LISA and LISA Pathfinder

NASA Technical Reports Server (NTRS)

Guzman, Felipe

2010-01-01

The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1mHz-100mHz. This observation band is inaccessible to ground-based detectors due to the large ground motions of the Earth. Gravitational wave sources for LISA include galactic binaries, mergers of supermasive black-hole binaries, extreme-mass-ratio inspirals, and possibly from as yet unimagined sources. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset oF 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such us spacecraft control with micro-newton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. An introduction to laser interferometric gravitational wave detection, ground-based observatories, and a detailed description of the two missions together with an overview of current investigations conducted by the community will bc discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented

History of Chandra X-Ray Observatory

NASA Image and Video Library

1999-08-01

This x-ray image of the Cassiopeia A (CAS A) supernova remnant is the official first light image of the Chandra X-Ray Observatory (CXO). The 5,000-second image was made with the Advanced Charged Coupled Device (CCD) Image Spectrometer (ACIS). Two shock waves are visible: A fast outer shock and a slower irner shock. The inner shock wave is believed to be due to the collision of ejecta from the supernova explosion with a circumstellar shell of material, heating it to a temperature of 10 million-degrees Celsius. The outer shock wave is analogous to an awesome sonic boom resulting from this collision The x-rays reveal a bright object near the center, which may be the long-sought neutron star or black hole remnant of the explosion that produced Cassiopeia A. Cassiopeia A is the 320-year-old remnant of a massive star that exploded. Located in the constellation Cassiopeia, it is 10 light-years across and 10,000 light-years from Earth. A supernova occurs when a massive star has used up its nuclear fuel and the pressure drops in the central core of the star. The matter in the core is crushed by gravity to higher and higher densities, and temperatures reach billions of degrees. Under these extreme conditions, nuclear reactions occur violently and catastrophically, reversing the collapse. A thermonuclear shock wave races through the now expanding stellar debris, fusing lighter elements into heavier ones and producing a brilliant visual outburst.

ngVLA Key Science Goal 5: Understanding the Formation and Evolution of Stellar and Supermassive Black Holes in the Era of Multi-Messenger Astronomy

NASA Astrophysics Data System (ADS)

Lazio, T. Joseph W.; Maccarone, Thomas J.; Chomiuk, Laura; ngVLA Science Working Group 2, ngVLA Science Working Group 4

2018-01-01

The ngVLA will be a powerful telescope for finding and studying black holes, surveying everything from the remnants of massive stars to the supermassive black holes that lurk in the centers of galaxies. High-resolution imaging abilities will allow the separation of low-luminosity black holes in the local Universe from background sources, thereby providing critical constraints on the formation and growth of black holes of all sizes. Its combination of sensitivity and angular resolution will provide new constraints on the physics of black hole accretion and jet formation. Combined with facilities across the spectrum and gravitational wave observatories, the ngVLA will provide crucial constraints on the interaction of supermassive black holes with their environments, with implications for the evolution of galaxies and the emission of gravitational waves from in-spiraling supermassive black holes. The ngVLA will identify the radio counterparts to transient sources discovered by gravitational wave, neutrino, and optical observatories, and its high-resolution, fast-mapping capabilities will make it the preferred instrument to pinpoint electromagnetic counterparts to events such as supermassive black hole mergers.Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

An Astrometric Observation of Binary Star System WDS 15559-0210 at the Great Basin Observatory

NASA Astrophysics Data System (ADS)

Musegades, Lila; Niebuhr, Cole; Graham, Mackenzie; Poore, Andrew; Freed, Rachel; Kenney, John; Genet, Russell

2018-04-01

Researchers at Concordia University Irvine measured the position angle and separation of the double star system WDS 15559-0210 using a SBIG STX-16803 CCD camera on the PlaneWave 0.7-m CDK 700 telescope at the Great Basin Observatory. Images of the binary star system were measured using AstroImageJ software. Twenty observations of WDS 15559-0210 were measured and analyzed. The calculated mean resulted in a position angle of 345.95° and a separation of 5.94". These measurements were consistent with the previous values for this binary system listed in the Washington Double Star Catalog.

Detecting Extrasolar Planets With Millimeter-Wave Observatories

NASA Astrophysics Data System (ADS)

1996-01-01

Do nearby stars have planetary systems like our own? How do such systems evolve? How common are such systems? Proposed radio observatories operating at millimeter wavelengths could start answering these questions within the next 6-10 years, according to scientists at the National Radio Astronomy Observatory (NRAO). Bryan Butler, Robert Brown, Richard Simon, Al Wootten and Darrel Emerson, all of NRAO, presented their findings today to the American Astronomical Society meeting in San Antonio, TX. Detecting planets circling other stars is a particularly difficult task, and only a few such planets have been discovered so far. In order to answer fundamental questions about planetary systems and their origin, scientists need to find and study many more extrasolar planets. According to the NRAO scientists, millimeter-wavelength observatories could provide valuable information about extrasolar planetary systems at all stages of their evolution. "With instruments planned by 2005, we could detect planets the size of Jupiter around a solar-type star out to a distance of 100 light-years," said Robert Brown, Associate Director of NRAO. "That means," he added, "that we could survey approximately 2,000 stars of different types to learn if they have planets this size." Millimeter waves occupy the portion of the electromagnetic spectrum between radio microwaves and infrared waves. Telescopes for observing at millimeter wavelengths utilize advanced electronic equipment similar to that used in radio telescopes observing at longer wavelengths. Millimeter-wave observatories offer a number of advantages in the search for extrasolar planets. Planned multi-antenna millimeter-wave telescopes can provide much higher resolving power, or ability to see fine detail, than current optical or infrared telescopes. Millimeter-wave observations would not be degraded by interference from the "zodiacal light" reflected by interplanetary dust, either in the extrasolar system or our own solar system. Another important advantage is that, at millimeter wavelengths, the star's brightness poses less of a problem for observers because, while it is still brighter than a planet, the difference in brightness between the two is far less. Because of the physical nature of the objects themselves, protoplanets in different stages of formation could readily be detected by advanced millimeter-wave observatories. The observatories that could provide these advantages are the Millimeter Array (MMA), a proposed 40-antenna millimeter-wave telescope that could be operational by 2005, and an upgraded version of the existing Very Large Array (VLA), a 27-antenna radio telescope in New Mexico. The MMA is a radio telescope designed to operate at wavelengths from 11.5 millimeters down to 0.5 millimeters, or frequencies from 26 to 650 GHz. It will use 40 precision antennas, each 8 meters in diameter, all operating in concert to produce extremely high- resolution images. As is done with the existing VLA and VLBA radio telescopes, the signals from all the MMA antennas will be processed in a special-purpose computer called a correlator. The processing of the signals corrects for atmospheric propagation effects and for the fact that the "synthesized telescope" is in fact made up of individual antennas. Planning for the MMA began as early as 1983, and a number of scientific workshops have allowed U.S. researchers to make known their needs for a millimeter-wave observatory to serve a wide variety of specialties. The National Science Foundation (NSF) provided initial design funding to NRAO in 1995 for MMA studies. Currently, MMA efforts are centered on selecting an appropriate site, which must be very high, dry and flat. A site at 16,500 feet elevation in northern Chile is now being tested. Hawaii's Mauna Kea is also under consideration. If funding is approved for the MMA, the instrument could be in operation by the year 2005. The MMA is expected to be an international instrument, with funding from both U.S. and foreign sources. The MMA will be capable of imaging planetary systems in the earliest stages of their formation. The MMA will be able to detect many more young, low-mass stellar systems and to examine them to determine if they have the disks from which planetary systems are formed. In addition, the MMA could be used to examine the properties of these disks in detail. The properties that could be examined include size, temperature, dust density and chemistry. A number of enhancements have been proposed to the MMA, including longer baselines for greater resolution, the ability to observe at higher frequencies, and greater signal bandwidth. This enhanced MMA would have the sensitivity to directly detect very young giant planets in the nearest star-forming regions, the resolving power to distinguish them from their central stars, and the ability to detect giant planets by measuring their gravitational effect upon their parent stars and thus determine their masses. The VLA, dedicated in 1980, also could contribute to the search for extrasolar planets if proposed upgrades are implemented. Though originally designed to operate at a highest frequency of 24 GHz, the VLA recently has been equipped with receivers for 40-50 GHz. Funding for receivers in this range, at a wavelength of 7 millimeters, was provided in 1993 by the government of Mexico. The VLA now has 13 of its 27 antennas equipped with these 40-50 GHz receivers. Plans for upgrading the VLA include equipping all remaining antennas with such receivers, improving its electronics, and improving its resolution by adding antennas at extended distances. The upgraded VLA will be able to study the inner parts of the dust disks surrounding young stars -- disks that are believed to be the precursors to planetary systems. The inner parts of such disks are obscured at shorter wavelengths. The enhanced VLA will be able to reveal processes occurring in these disks at scales comparable to the size of our own Solar System. "The reason we hope to search for extrasolar planets with millimeter-wave telescopes is that we can build on the experience U.S. astronomers have gained with both millimeter observing and aperture-synthesis telescopes such as the VLA over the past two or three decades," said Brown. He added, "We look forward to applying this expertise to the challenge of answering one of mankind's oldest questions."

Multi-Wave Station of Solar Monitoring

NASA Astrophysics Data System (ADS)

Korokhin, V.; Akimov, L.; Beletsky, S.; Belkina, I.; Velikodsky, Y.; Marchenko, G.; Shaparenko, E.

A technical description of the contemporary solar telescope of the Kharkov Astronomical Observatory (http://khassm.virtualave.net) is given, and the plan to future development is sketched. A wide range monitoring of solar activity including observations near UV range in Balmer continuum and the IR line of He 1083 nm is presented.

Generation of Shear Alfvén Waves by Repetitive High Power Microwave Pulses Near the Electron Plasma Frequency - A laboratory study of a ``Virtual Antenna''

NASA Astrophysics Data System (ADS)

Wang, Yuhou; Gekelman, Walter; Pribyl, Patrick; van Compernolle, Bart; Papadopoulos, Konstantinos

2015-11-01

ELF / ULF waves are important in terrestrial radio communications but difficult to launch using ground-based structures due to their enormous wavelengths. In spite of this generation of such waves by field-aligned ionospheric heating modulation was first demonstrated using the HAARP facility. In the future heaters near the equator will be constructed and laboratory experiments on cross-field wave propagation could be key to the program's success. Here we report a detailed laboratory study conducted on the Large Plasma Device (LaPD) at UCLA. In this experiment, ten rapid pulses of high power microwaves (250 kW X-band) near the plasma frequency were launched transverse to the background field, and were modulated at a variable fraction (0.1-1.0) of fci. Along with bulk electron heating and density modification, the microwave pulses generated a population of fast electrons. The field-aligned current carried by the fast electrons acted as an antenna that radiated shear Alfvén waves. It was demonstrated that a controllable arbitrary frequency (f

Formation of virtual isthmus: A new scenario of spiral wave death after a decrease in excitability

NASA Astrophysics Data System (ADS)

Erofeev, I. S.; Agladze, K. I.

2015-11-01

Termination of rotating (spiral) waves or reentry is crucial when fighting with the most dangerous cardiac tachyarrhythmia. To increase the efficiency of the antiarrhythmic drugs as well as finding new prospective ones it is decisive to know the mechanisms how they act and influence the reentry dynamics. The most popular view on the mode of action of the contemporary antiarrhythmic drugs is that they increase the core of the rotating wave (reentry) to that extent that it is not enough space in the real heart for the reentry to exist. Since the excitation in cardiac cells is essentially change of the membrane potential, it relies on the functioning of the membrane ion channels. Thus, membrane ion channels serve as primary targets for the substances, which may serve as antiarrhythmics. At least, the entire group of antiarrhythmics class I (modulating activity of sodium channels) and partially class IV (modulating activity of calcium channels) are believed to destabilize and terminate reentry by decreasing the excitability of cardiac tissue. We developed an experimental model employing cardiac tissue culture and photosensitizer (AzoTAB) to study the process of the rotating wave termination while decreasing the excitability of the tissue. A new scenario of spiral wave cessation was observed: an asymmetric growth of the rotating wave core and subsequent formation of a virtual isthmus, which eventually caused a conduction block and the termination of the reentry.

Gravitational wave astronomy - astronomy of the 21st century

NASA Astrophysics Data System (ADS)

Dhurandhar, S. V.

2011-03-01

An enigmatic prediction of Einstein's general theory of relativity is gravitational waves. With the observed decay in the orbit of the Hulse-Taylor binary pulsar agreeing within a fraction of a percent with the theoretically computed decay from Einstein's theory, the existence of gravitational waves was firmly established. Currently there is a worldwide effort to detect gravitational waves with inteferometric gravitational wave observatories or detectors and several such detectors have been built or being built. The initial detectors have reached their design sensitivities and now the effort is on to construct advanced detectors which are expected to detect gravitational waves from astrophysical sources. The era of gravitational wave astronomy has arrived. This article describes the worldwide effort which includes the effort on the Indian front - the IndIGO project -, the principle underlying interferometric detectors both on ground and in space, the principal noise sources that plague such detectors, the astrophysical sources of gravitational waves that one expects to detect by these detectors and some glimpse of the data analysis methods involved in extracting the very weak gravitational wave signals from detector noise.

Gravitational wave astronomy— astronomy of the 21st century

NASA Astrophysics Data System (ADS)

Dhurandhar, S. V.

2011-12-01

An enigmatic prediction of Einstein's general theory of relativity is gravitational waves. With the observed decay in the orbit of the Hulse-Taylor binary pulsar agreeing within a fraction of a percent with the theoretically computed decay from Einstein's theory, the existence of gravitational waves was firmly established. Currently there is a worldwide effort to detect gravitational waves with inteferometric gravitational wave observatories or detectors and several such detectors have been built or are being built. The initial detectors have reached their design sensitivities and now the effort is on to construct advanced detectors which are expected to detect gravitational waves from astrophysical sources. The era of gravitational wave astronomy has arrived. This article describes the worldwide effort which includes the effort on the Indian front— the IndIGO project —, the principle underlying interferometric detectors both on ground and in space, the principal noise sources that plague such detectors, the astrophysical sources of gravitational waves that one expects to detect by these detectors and some glimpse of the data analysis methods involved in extracting the very weak gravitational wave signals from detector noise.

Astronomy in Iraq

NASA Astrophysics Data System (ADS)

Alsabti, A. W.

2006-08-01

The history of modern Iraqi astronomy is reviewed. During the early 1970's Iraqi astronomy witnessed significant growth through the introduction of the subject at university level and extensively within the school curriculum. In addition, astronomy was popularised in the media, a large planetarium was built in Baghdad, plus a smaller one in Basra. Late 1970 witnessed the construction of the Iraqi National Observatory at Mount Korek in Iraqi Kurdistan. The core facilities of the Observatory included 3.5-meter and 1.25-meter optical telescopes, and a 30-meter radio telescope for millimetre wavelength astronomy. The Iraqi Astronomical Society was founded and Iraq joined the IAU in 1976. During the regime of Saddam Hussain in the 1980's, the Observatory was attacked by Iranian artillery during the Iraq-Iran war, and then again during the second Gulf war by the US air force. Years of sanctions during the 1990's left Iraq cut off from the rest of the international scientific community. Subscriptions to astronomical journals were halted and travel to conferences abroad was virtually non-existent. Most senior astronomers left the country for one reason or another. Support from expatriate Iraqi astronomers existed (and still exists) however, this is not sufficient. Recent changes in Iraq, and the fall of Saddam's regime, has meant that scientific communication with the outside world has resumed to a limited degree. The Ministry of Higher Education in Baghdad, Baghdad University and the Iraqi National Academy of Science, have all played active roles in re-establishing Iraqi astronomy and re-building the damaged Observatory at Mount Korek. More importantly the University of Sallahudin in Erbil, capital of Iraqi Kurdistan, has taken particular interest in astronomy and the Observatory. Organized visits to the universities, and also to the Observatory, have given us a first-hand assessment of the scale of the damage to the Observatory, as well as the needs of astronomy teaching and research. Joint supervision for postgraduate level research was organized between local and Iraqi expatriate astronomers. The IAU was among the first international organizations to offer assistance. Many observatories worldwide have also given support. Plans will be proposed for re-building the Observatory, supporting teaching and research, and establishing an institute for astronomy in Erbil, together with further suggestions on how the international astronomical community can assist Iraqi astronomers.

Assessing the Impact of Lesson Study on the Teaching Practice of Middle School Science Teachers

ERIC Educational Resources Information Center

Grove, Michael C.

2011-01-01

Despite wave after wave of educational reform in the United States our students continue to lag behind their peers in other industrialized countries on virtually all measures of academic achievement. Effective professional development (PD) is seen as a key to improving instructional practice and therefore student learning, but traditional forms of…

IAU South West Asian ROAD

NASA Astrophysics Data System (ADS)

Mickaelian, Areg; Azatyan, Naira; Farmanyan, Sona; Mikayelyan, Gor

2016-10-01

Armenia is hosting the IAU South West Asian (SWA) Regional Office of Astronomy for Development (ROAD). It is a county of ancient astronomy and is also rich in modern astronomical facilities and infrastructures, hence may successfully serve as a regional center for various activities. Byurakan Astrophysical Observatory (BAO) has 2.6m and 1m Schmidt, as well as a number of smaller telescopes that are an observational basis for joint projects and collaborations. Armenian Virtual Observatory (ArVO) is hosting astronomical databases, such as the Digitized First Byurakan Survey (DFBS) and may also serve as a basis for development of VO structures in this region. Recently we have conducted a number of new activities; a meeting on ``Relation of Astronomy to other Sciences, Culture and Society" (RASCS) was organized by BAO and Armenian Astronomical Society (ArAS) in Oct 2014 in Byurakan. Activities related to Archaeoastronomy and Astronomy in Culture (AAC) were initiated as well. Discussions on future Armenian-Iranian collaboration in astronomy were carried out, including an Armenian-Iranian Astronomical Workshop held in Oct 2015 in Byurakan. Similar workshops have been carried out between BAO and Abastumani Astronomical Observatory (AbAO, Georgia) since 1974.

The igmspec database of public spectra probing the intergalactic medium

NASA Astrophysics Data System (ADS)

Prochaska, J. X.

2017-04-01

We describe v02 of igmspec, a database of publicly available ultraviolet, optical, and near-infrared spectra that probe the intergalactic medium (IGM). This database, a child of the specdb repository in the specdb github organization, comprises 403 277 unique sources and 434 686 spectra obtained with the world's greatest observatories. All of these data are distributed in a single ≈ 25GB HDF5 file maintained at the University of California Observatories and the University of California, Santa Cruz. The specdb software package includes Python scripts and modules for searching the source catalog and spectral datasets, and software links to the linetools package for spectral analysis. The repository also includes software to generate private spectral datasets that are compliant with International Virtual Observatory Alliance (IVOA) protocols and a Python-based interface for IVOA Simple Spectral Access queries. Future versions of igmspec will ingest other sources (e.g. gamma-ray burst afterglows) and other surveys as they become publicly available. The overall goal is to include every spectrum that effectively probes the IGM. Future databases of specdb may include publicly available galaxy spectra (exgalspec) and published supernovae spectra (snspec). The community is encouraged to join the effort on github: https://github.com/specdb.

Strong ground motion prediction using virtual earthquakes.

PubMed

Denolle, M A; Dunham, E M; Prieto, G A; Beroza, G C

2014-01-24

Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.

RTS2: a powerful robotic observatory manager

NASA Astrophysics Data System (ADS)

Kubánek, Petr; Jelínek, Martin; Vítek, Stanislav; de Ugarte Postigo, Antonio; Nekola, Martin; French, John

2006-06-01

RTS2, or Remote Telescope System, 2nd Version, is an integrated package for remote telescope control under the Linux operating system. It is designed to run in fully autonomous mode, picking targets from a database table, storing image meta data to the database, processing images and storing their WCS coordinates in the database and offering Virtual-Observatory enabled access to them. It is currently running on various telescope setups world-wide. For control of devices from various manufacturers we developed an abstract device layer, enabling control of all possible combinations of mounts, CCDs, photometers, roof and cupola controllers. We describe the evolution of RTS2 from Python-based RTS to C and later C++ based RTS2, focusing on the problems we faced during development. The internal structure of RTS2, focusing on object layering, which is used to uniformly control various devices and provides uniform reporting layer, is also discussed.

Wave phenomena in sunspots

NASA Astrophysics Data System (ADS)

Löhner-Böttcher, Johannes

2016-03-01

Context: The dynamic atmosphere of the Sun exhibits a wealth of magnetohydrodynamic (MHD) waves. In the presence of strong magnetic fields, most spectacular and powerful waves evolve in the sunspot atmosphere. Allover the sunspot area, continuously propagating waves generate strong oscillations in spectral intensity and velocity. The most prominent and fascinating phenomena are the 'umbral flashes' and 'running penumbral waves' as seen in the sunspot chromosphere. Their nature and relation have been under intense discussion in the last decades. Aims: Waves are suggested to propagate upward along the magnetic field lines of sunspots. An observational study is performed to prove or disprove the field-guided nature and coupling of the prevalent umbral and penumbral waves. Comprehensive spectroscopic observations at high resolution shall provide new insights into the wave characteristics and distribution across the sunspot atmosphere. Methods: Two prime sunspot observations were carried out with the Dunn Solar Telescope at the National Solar Observatory in New Mexico and with the Vacuum Tower Telescope at the Teide Observatory on Tenerife. The two-dimensional spectroscopic observations were performed with the interferometric spectrometers IBIS and TESOS. Multiple spectral lines are scanned co-temporally to sample the dynamics at the photospheric and chromospheric layers. The time series (1 - 2.5 h) taken at high spatial and temporal resolution are analyzed according to their evolution in spectral intensities and Doppler velocities. A wavelet analysis was used to obtain the wave power and dominating wave periods. A reconstruction of the magnetic field inclination based on sunspot oscillations was developed. Results and conclusions: Sunspot oscillations occur continuously in spectral intensity and velocity. The obtained wave characteristics of umbral flashes and running penumbral waves strongly support the scenario of slow-mode magnetoacoustic wave propagation along the magnetic field lines. Signatures of umbral flashes and running penumbral waves are found already in the middle to upper photosphere. The signal and velocity increases toward the chromosphere. The shock wave behavior of the umbral flashes is confirmed by the evolving saw-tooth pattern in velocity and the strong downward motion of the plasma right after the passage of the shock front. The power spectra and peak periods of sunspot waves vary significantly with atmospheric altitude and position within the sunspot. In the vertical field of the umbra, the mixture of wave periods in the lower photosphere transforms into a domination of the 2.5min range in the upper photosphere and chromosphere. In the differentially inclined penumbra, the dominating wave periods increase with radial distance. The acoustic cut-off frequency which blocks the propagation of long-period waves is considered to increase with the field inclination and the ambient sound speed. The reconstruction of the sunspot's magnetic field inclination based on the peak period distribution yields consistent results with the inferred photospheric and extrapolated coronal magnetic field.

iRODS: A Distributed Data Management Cyberinfrastructure for Observatories

NASA Astrophysics Data System (ADS)

Rajasekar, A.; Moore, R.; Vernon, F.

2007-12-01

Large-scale and long-term preservation of both observational and synthesized data requires a system that virtualizes data management concepts. A methodology is needed that can work across long distances in space (distribution) and long-periods in time (preservation). The system needs to manage data stored on multiple types of storage systems including new systems that become available in the future. This concept is called infrastructure independence, and is typically implemented through virtualization mechanisms. Data grids are built upon concepts of data and trust virtualization. These concepts enable the management of collections of data that are distributed across multiple institutions, stored on multiple types of storage systems, and accessed by multiple types of clients. Data virtualization ensures that the name spaces used to identify files, users, and storage systems are persistent, even when files are migrated onto future technology. This is required to preserve authenticity, the link between the record and descriptive and provenance metadata. Trust virtualization ensures that access controls remain invariant as files are moved within the data grid. This is required to track the chain of custody of records over time. The Storage Resource Broker (http://www.sdsc.edu/srb) is one such data grid used in a wide variety of applications in earth and space sciences such as ROADNet (roadnet.ucsd.edu), SEEK (seek.ecoinformatics.org), GEON (www.geongrid.org) and NOAO (www.noao.edu). Recent extensions to data grids provide one more level of virtualization - policy or management virtualization. Management virtualization ensures that execution of management policies can be automated, and that rules can be created that verify assertions about the shared collections of data. When dealing with distributed large-scale data over long periods of time, the policies used to manage the data and provide assurances about the authenticity of the data become paramount. The integrated Rule-Oriented Data System (iRODS) (http://irods.sdsc.edu) provides the mechanisms needed to describe not only management policies, but also to track how the policies are applied and their execution results. The iRODS data grid maps management policies to rules that control the execution of the remote micro-services. As an example, a rule can be created that automatically creates a replica whenever a file is added to a specific collection, or extracts its metadata automatically and registers it in a searchable catalog. For the replication operation, the persistent state information consists of the replica location, the creation date, the owner, the replica size, etc. The mechanism used by iRODS for providing policy virtualization is based on well-defined functions, called micro-services, which are chained into alternative workflows using rules. A rule engine, based on the event-condition-action paradigm executes the rule-based workflows after an event. Rules can be deferred to a pre-determined time or executed on a periodic basis. As the data management policies evolve, the iRODS system can implement new rules, new micro-services, and new state information (metadata content) needed to manage the new policies. Each sub- collection can be managed using a different set of policies. The discussion of the concepts in rule-based policy virtualization and its application to long-term and large-scale data management for observatories such as ORION and NEON will be the basis of the paper.

MAGNETIC UNTWISTING IN SOLAR JETS THAT GO INTO THE OUTER CORONA IN POLAR CORONAL HOLES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A., E-mail: ron.moore@nasa.gov

We study 14 large solar jets observed in polar coronal holes. In EUV movies from the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), each jet appears similar to most X-ray jets and EUV jets that erupt in coronal holes; but each is exceptional in that it goes higher than most, so high that it is observed in the outer corona beyond 2.2 R{sub Sun} in images from the Solar and Heliospheric Observatory/Large Angle Spectroscopic Coronagraph (LASCO)/C2 coronagraph. From AIA He ii 304 Å movies and LASCO/C2 running-difference images of these high-reaching jets, we find: (1) the front of the jet transitsmore » the corona below 2.2 R{sub Sun} at a speed typically several times the sound speed; (2) each jet displays an exceptionally large amount of spin as it erupts; (3) in the outer corona, most of the jets display measureable swaying and bending of a few degrees in amplitude; in three jets the swaying is discernibly oscillatory with a period of order 1 hr. These characteristics suggest that the driver in these jets is a magnetic-untwisting wave that is basically a large-amplitude (i.e., nonlinear) torsional Alfvén wave that is put into the reconnected open field in the jet by interchange reconnection as the jet erupts. From the measured spinning and swaying, we estimate that the magnetic-untwisting wave loses most of its energy in the inner corona below 2.2 R{sub Sun}. We point out that the torsional waves observed in Type-II spicules might dissipate in the corona in the same way as the magnetic-untwisting waves in our big jets, and thereby power much of the coronal heating in coronal holes.« less

Limiting the effects of earthquakes on gravitational-wave interferometers

NASA Astrophysics Data System (ADS)

Coughlin, Michael; Earle, Paul; Harms, Jan; Biscans, Sebastien; Buchanan, Christopher; Coughlin, Eric; Donovan, Fred; Fee, Jeremy; Gabbard, Hunter; Guy, Michelle; Mukund, Nikhil; Perry, Matthew

2017-02-01

Ground-based gravitational wave interferometers such as the Laser Interferometer Gravitational-wave Observatory (LIGO) are susceptible to ground shaking from high-magnitude teleseismic events, which can interrupt their operation in science mode and significantly reduce their duty cycle. It can take several hours for a detector to stabilize enough to return to its nominal state for scientific observations. The down time can be reduced if advance warning of impending shaking is received and the impact is suppressed in the isolation system with the goal of maintaining stable operation even at the expense of increased instrumental noise. Here, we describe an early warning system for modern gravitational-wave observatories. The system relies on near real-time earthquake alerts provided by the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA). Preliminary low latency hypocenter and magnitude information is generally available in 5 to 20 min of a significant earthquake depending on its magnitude and location. The alerts are used to estimate arrival times and ground velocities at the gravitational-wave detectors. In general, 90% of the predictions for ground-motion amplitude are within a factor of 5 of measured values. The error in both arrival time and ground-motion prediction introduced by using preliminary, rather than final, hypocenter and magnitude information is minimal. By using a machine learning algorithm, we develop a prediction model that calculates the probability that a given earthquake will prevent a detector from taking data. Our initial results indicate that by using detector control configuration changes, we could prevent interruption of operation from 40 to 100 earthquake events in a 6-month time-period.

The Coronal Analysis of SHocks and Waves (CASHeW) framework

NASA Astrophysics Data System (ADS)

Kozarev, Kamen A.; Davey, Alisdair; Kendrick, Alexander; Hammer, Michael; Keith, Celeste

2017-11-01

Coronal bright fronts (CBF) are large-scale wavelike disturbances in the solar corona, related to solar eruptions. They are observed (mostly in extreme ultraviolet (EUV) light) as transient bright fronts of finite width, propagating away from the eruption source location. Recent studies of individual solar eruptive events have used EUV observations of CBFs and metric radio type II burst observations to show the intimate connection between waves in the low corona and coronal mass ejection (CME)-driven shocks. EUV imaging with the atmospheric imaging assembly instrument on the solar dynamics observatory has proven particularly useful for detecting large-scale short-lived CBFs, which, combined with radio and in situ observations, holds great promise for early CME-driven shock characterization capability. This characterization can further be automated, and related to models of particle acceleration to produce estimates of particle fluxes in the corona and in the near Earth environment early in events. We present a framework for the coronal analysis of shocks and waves (CASHeW). It combines analysis of NASA Heliophysics System Observatory data products and relevant data-driven models, into an automated system for the characterization of off-limb coronal waves and shocks and the evaluation of their capability to accelerate solar energetic particles (SEPs). The system utilizes EUV observations and models written in the interactive data language. In addition, it leverages analysis tools from the SolarSoft package of libraries, as well as third party libraries. We have tested the CASHeW framework on a representative list of coronal bright front events. Here we present its features, as well as initial results. With this framework, we hope to contribute to the overall understanding of coronal shock waves, their importance for energetic particle acceleration, as well as to the better ability to forecast SEP events fluxes.

Limiting the effects of earthquakes on gravitational-wave interferometers

USGS Publications Warehouse

Coughlin, Michael; Earle, Paul; Harms, Jan; Biscans, Sebastien; Buchanan, Christopher; Coughlin, Eric; Donovan, Fred; Fee, Jeremy; Gabbard, Hunter; Guy, Michelle; Mukund, Nikhil; Perry, Matthew

2017-01-01

Ground-based gravitational wave interferometers such as the Laser Interferometer Gravitational-wave Observatory (LIGO) are susceptible to ground shaking from high-magnitude teleseismic events, which can interrupt their operation in science mode and significantly reduce their duty cycle. It can take several hours for a detector to stabilize enough to return to its nominal state for scientific observations. The down time can be reduced if advance warning of impending shaking is received and the impact is suppressed in the isolation system with the goal of maintaining stable operation even at the expense of increased instrumental noise. Here, we describe an early warning system for modern gravitational-wave observatories. The system relies on near real-time earthquake alerts provided by the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA). Preliminary low latency hypocenter and magnitude information is generally available in 5 to 20 min of a significant earthquake depending on its magnitude and location. The alerts are used to estimate arrival times and ground velocities at the gravitational-wave detectors. In general, 90% of the predictions for ground-motion amplitude are within a factor of 5 of measured values. The error in both arrival time and ground-motion prediction introduced by using preliminary, rather than final, hypocenter and magnitude information is minimal. By using a machine learning algorithm, we develop a prediction model that calculates the probability that a given earthquake will prevent a detector from taking data. Our initial results indicate that by using detector control configuration changes, we could prevent interruption of operation from 40 to 100 earthquake events in a 6-month time-period.

ADDOSS: Autonomously Deployed Deep-ocean Seismic System - Communications Gateway for Ocean Observatories

NASA Astrophysics Data System (ADS)

Laske, Gabi; Berger, Jon; Orcutt, John; Babcock, Jeff

2014-05-01

We describe an autonomously deployable, communications gateway designed to provide long-term and near real-time data from ocean observatories. The key features of this new system are its abilities to telemeter sensor data from the seafloor to shore without cables or moorings, and to be deployed without a ship, thereby greatly reducing life-cycle costs. The free-floating surface communications gateway utilizes a Liquid Robotics wave glider comprising a surfboard-sized float towed by a tethered, submerged glider, which converts wave motion into thrust. For navigation, the wave glider is equipped with a small computer, a GPS receiver, a rudder, solar panels and batteries, and an Iridium satellite modem. Acoustic communications connect the subsea instruments and the surface gateway while communications between the gateway and land are provided by the Iridium satellite constellation. Wave gliders have demonstrated trans-oceanic range and long-term station keeping capabilities. The acoustics communications package is mounted in a shallow tow body which utilizes a WHOI micro modem and a Benthos low frequency, directional transducer. A matching modem and transducer is mounted on the ocean bottom package. Tests of the surface gateway in 4350 m of water demonstrated an acoustic efficiency of approximately 396 bits/J. For example, it has the ability to send 4 channels of compressed, 1 sample per second data from the ocean bottom to the gateway with an average power draw of approximately 0.15 W and a latency of less than 3 minutes. This gateway is used to send near real-time data from a broadband ocean bottom seismic observatory, first during short week-to-months long test deployments but will ultimately be designed for a two-year operational life. Such data from presently unobserved oceanic areas are critical for both national and international agencies in monitoring and characterizing earthquakes, tsunamis, and nuclear explosions. We present initial results from a two short-term OBS test deployments off-shore La Jolla, at water depths of 1000 m and of nearly 4000 m.

Spatiotemporal Visualization of Tsunami Waves Using Kml on Google Earth

NASA Astrophysics Data System (ADS)

Mohammadi, H.; Delavar, M. R.; Sharifi, M. A.; Pirooz, M. D.

2017-09-01

Disaster risk is a function of hazard and vulnerability. Risk is defined as the expected losses, including lives, personal injuries, property damages, and economic disruptions, due to a particular hazard for a given area and time period. Risk assessment is one of the key elements of a natural disaster management strategy as it allows for better disaster mitigation and preparation. It provides input for informed decision making, and increases risk awareness among decision makers and other stakeholders. Virtual globes such as Google Earth can be used as a visualization tool. Proper spatiotemporal graphical representations of the concerned risk significantly reduces the amount of effort to visualize the impact of the risk and improves the efficiency of the decision-making process to mitigate the impact of the risk. The spatiotemporal visualization of tsunami waves for disaster management process is an attractive topic in geosciences to assist investigation of areas at tsunami risk. In this paper, a method for coupling virtual globes with tsunami wave arrival time models is presented. In this process we have shown 2D+Time of tsunami waves for propagation and inundation of tsunami waves, both coastal line deformation, and the flooded areas. In addition, the worst case scenario of tsunami on Chabahar port derived from tsunami modelling is also presented using KML on google earth.

HAARP-based Investigations of Lightning-induced Nonlinearities within the D-Region Ionosphere

NASA Astrophysics Data System (ADS)

Moore, R. C.

2015-12-01

It is well-documented that energetic lightning can produce fantastical events with the lower ionosphere. Although the High-frequency Active Auroral Research Program (HAARP) transmitter is not as powerful as lightning, it can be used to investigate the nonlinear interactions that occur within the lower ionosphere, many of which also occur during lightning-induced ionospheric events. This paper presents the best experimental results obtained during D-region modification experiments performed by the University of Florida at the HAARP observatory between 2007 and 2014, including ELF/VLF wave generation experiments, wave-wave mixing experiments, and cross-modulation experiments. We emphasize the physical processes important for lightning-ionosphere interactions that can be directly investigated using HAARP.

High Power Radio Wave Interactions within the D-Region Ionosphere

NASA Astrophysics Data System (ADS)

Moore, R. C.

2014-12-01

This paper highlights the best results obtained during D-region modification experiments performed by the University of Florida at the High-frequency Active Auroral Research Program (HAARP) observatory between 2007 and 2014. Over this period, we have seen a tremendous improvement in ELF/VLF wave generation efficiency. We have identified methods to characterize ambient and modified ionospheric properties and to discern and quantify specific types of interactions. We have demonstrated several important implications of HF cross-modulation effects, including "Doppler Spoofing" on HF radio waves. Throughout this talk, observations are compared with the predictions of an ionospheric HF heating model to provide context and guidance for future D-region modification experiments.

An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi -GBM Detection of GRB 170817A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldstein, A.; Roberts, O. J.; Connaughton, V.

On 2017 August 17 at 12:41:06 UTC the Fermi Gamma-ray Burst Monitor (GBM) detected and triggered on the short gamma-ray burst (GRB) 170817A. Approximately 1.7 s prior to this GRB, the Laser Interferometer Gravitational-wave Observatory triggered on a binary compact merger candidate associated with the GRB. This is the first unambiguous coincident observation of gravitational waves and electromagnetic radiation from a single astrophysical source and marks the start of gravitational-wave multi-messenger astronomy. We report the GBM observations and analysis of this ordinary short GRB, which extraordinarily confirms that at least some short GRBs are produced by binary compact mergers.

An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A

NASA Astrophysics Data System (ADS)

Goldstein, A.; Veres, P.; Burns, E.; Briggs, M. S.; Hamburg, R.; Kocevski, D.; Wilson-Hodge, C. A.; Preece, R. D.; Poolakkil, S.; Roberts, O. J.; Hui, C. M.; Connaughton, V.; Racusin, J.; von Kienlin, A.; Dal Canton, T.; Christensen, N.; Littenberg, T.; Siellez, K.; Blackburn, L.; Broida, J.; Bissaldi, E.; Cleveland, W. H.; Gibby, M. H.; Giles, M. M.; Kippen, R. M.; McBreen, S.; McEnery, J.; Meegan, C. A.; Paciesas, W. S.; Stanbro, M.

2017-10-01

On 2017 August 17 at 12:41:06 UTC the Fermi Gamma-ray Burst Monitor (GBM) detected and triggered on the short gamma-ray burst (GRB) 170817A. Approximately 1.7 s prior to this GRB, the Laser Interferometer Gravitational-wave Observatory triggered on a binary compact merger candidate associated with the GRB. This is the first unambiguous coincident observation of gravitational waves and electromagnetic radiation from a single astrophysical source and marks the start of gravitational-wave multi-messenger astronomy. We report the GBM observations and analysis of this ordinary short GRB, which extraordinarily confirms that at least some short GRBs are produced by binary compact mergers.

A modified Friedmann equation for a system with varying gravitational mass

NASA Astrophysics Data System (ADS)

Gorkavyi, Nick; Vasilkov, Alexander

2018-05-01

The Laser Interferometer Gravitational-Wave Observatory (LIGO) detection of gravitational waves that take away 5 per cent of the total mass of two merging black holes points out on the importance of considering varying gravitational mass of a system. Using an assumption that the energy-momentum pseudo-tensor of gravitational waves is not considered as a source of gravitational field, we analyse a perturbation of the Friedmann-Robertson-Walker metric caused by the varying gravitational mass of a system. This perturbation leads to a modified Friedmann equation that contains a term similar to the `cosmological constant'. Theoretical estimates of the effective cosmological constant quantitatively corresponds to observed cosmological acceleration.

Searching for photon-sector Lorentz violation using gravitational-wave detectors

DOE PAGES

Kostelecký, V. Alan; Melissinos, Adrian C.; Mewes, Matthew

2016-08-04

Here, we study the prospects for using interferometers in gravitational-wave detectors as tools to search for photon-sector violations of Lorentz symmetry. Existing interferometers are shown to be exquisitely sensitive to tiny changes in the effective refractive index of light occurring at frequencies around and below the microhertz range, including at the harmonics of the frequencies of the Earth's sidereal rotation and annual revolution relevant for tests of Lorentz symmetry. We use preliminary data obtained by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2006-2007 to place constraints on coefficients for Lorentz violation in the photon sector exceeding current limits by aboutmore » four orders of magnitude.« less

Error analysis of numerical gravitational waveforms from coalescing binary black holes

NASA Astrophysics Data System (ADS)

Fong, Heather; Chu, Tony; Kumar, Prayush; Pfeiffer, Harald; Boyle, Michael; Hemberger, Daniel; Kidder, Lawrence; Scheel, Mark; Szilagyi, Bela; SXS Collaboration

2016-03-01

The Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO) has finished a successful first observation run and will commence its second run this summer. Detection of compact object binaries utilizes matched-filtering, which requires a vast collection of highly accurate gravitational waveforms. This talk will present a set of about 100 new aligned-spin binary black hole simulations. I will discuss their properties, including a detailed error analysis, which demonstrates that the numerical waveforms are sufficiently accurate for gravitational wave detection purposes, as well as for parameter estimation purposes.

Solar terrestrial observatory

NASA Technical Reports Server (NTRS)

1981-01-01

Eight basic solar-terrestrial scientific objectives that benefit from the Shuttle/Platform approach and a program of measurements for each are discussed. The objectives are to understand: (1) solar variability, (2) wave-particle processes, (3) magnetosphere-ionosphere mass transport, (4) the global electric circuit, (5) upper atmospheric dynamics, (6) middle atmospheric chemistry and energetics, (7) lower atmospheric turbidity, and (8) planetary atmospheric waves. A two stage approach to a multidisciplinary payload is developed: an initial STO, that uses a single platform in a low-Earth orbit, and an advanced STO that uses two platforms in differing orbits.

Space-Based Gravitational-Wave Observatory (SGO) Mission Concept Study

NASA Technical Reports Server (NTRS)

Livas, Jeffrey; McNamara, Paul; Jennrich, Oliver

2012-01-01

The LISA Mission Concept has been under study for over two decades as a space-based gravitational-wave detector capable of observing astrophysical sources in the 0.0001 to 1 Hz band. The concept has consistently received strong recommendations from various review panels based on the expected science, most recently from the US Astr02010 Decadal Review. Budget constraints have led both the US and European Space agencies to search for lower cost options. We report results from the US effort to explore the tradeoffs between mission cost and science return.

Site Effects on Regional Seismograms Recorded in the Vicinity of Weston Observatory

DTIC Science & Technology

1993-09-30

flanks of the active volcanoes of Mauna Loa and Kilauea . The distances between the sites ranged from a few km to over 100 km. Although there is little...on the island of Hawaii using S-wave coda spectral ratios for frequencies between 1.5 and 15-Hz. They used 40 vertical I-Hz seismometers, and recorded...for the island of Hawaii , Bull. Seis Soc. Am-, 12 No- 3 1151-1185. Mayeda, K., S. Koyanagi, and K. Aki (1991). Site amplification from S-wave coda in

Analysis and Modeling of the Shear Waves Generated by Explosions at the San Andreas Fault Observatory at Depth

DTIC Science & Technology

2012-09-01

09NA29328 Proposal No. BAA09-69 ABSTRACT Using a deep deployment of an 80-element, 3-component borehole seismic array stretching from 1.5 to 2.3...Administration (NNSA). 14. ABSTRACT Using a deep deployment of an 80-element, 3-component borehole seismic array stretching from 1.5 to 2.3 kilometer (km) depth...in the lower half of the borehole array . The strong velocity discontinuity at 2.0 km depth gives rise to another converted S wave, best seen in

Astronomy Map of the World

NASA Astrophysics Data System (ADS)

Veras, D.

2017-09-01

I have created an online clickable and zoom-enabled world map - now viewed over 5,400 times - that contains weblinks to institutions where astronomy is either researched professionally and / or and taught in classrooms at the university level. Not included are stand-alone museums, planetariums, amateur astronomical societies, virtual institutes, nor observatories which do not fulfill this criteria. One can click on a marker to access the relevant institute. The map currently contains 697 institutes, and has multiple potential uses for undergraduate students, graduate students, postdocs, faculty and journal editors.

Illusion media: Generating virtual objects using realizable metamaterials

NASA Astrophysics Data System (ADS)

Jiang, Wei Xiang; Ma, Hui Feng; Cheng, Qiang; Cui, Tie Jun

2010-03-01

We propose a class of optical transformation media, illusion media, which render the enclosed object invisible and generate one or more virtual objects as desired. We apply the proposed media to design a microwave device, which transforms an actual object into two virtual objects. Such an illusion device exhibits unusual electromagnetic behavior as verified by full-wave simulations. Different from the published illusion devices which are composed of left-handed materials with simultaneously negative permittivity and permeability, the proposed illusion media have finite and positive permittivity and permeability. Hence the designed device could be realizable using artificial metamaterials.

Assessment of virtual towers performed with scanning wind lidars and Ka-band radars during the XPIA experiment

DOE PAGES

Debnath, Mithu; Iungo, Giacomo Valerio; Brewer, W. Alan; ...

2017-03-29

During the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign, which was carried out at the Boulder Atmospheric Observatory (BAO) in spring 2015, multiple-Doppler scanning strategies were carried out with scanning wind lidars and Ka-band radars. Specifically, step–stare measurements were collected simultaneously with three scanning Doppler lidars, while two scanning Ka-band radars carried out simultaneous range height indicator (RHI) scans. The XPIA experiment provided the unique opportunity to compare directly virtual-tower measurements performed simultaneously with Ka-band radars and Doppler wind lidars. Furthermore, multiple-Doppler measurements were assessed against sonic anemometer data acquired from the meteorological tower (met-tower) present at the BAOmore » site and a lidar wind profiler. As a result, this survey shows that – despite the different technologies, measurement volumes and sampling periods used for the lidar and radar measurements – a very good accuracy is achieved for both remote-sensing techniques for probing horizontal wind speed and wind direction with the virtual-tower scanning technique.« less

Ground Motion Prediction for M7+ scenarios on the San Andreas Fault using the Virtual Earthquake Approach

NASA Astrophysics Data System (ADS)

Denolle, M.; Dunham, E. M.; Prieto, G.; Beroza, G. C.

2013-05-01

There is no clearer example of the increase in hazard due to prolonged and amplified shaking in sedimentary, than the case of Mexico City in the 1985 Michoacan earthquake. It is critically important to identify what other cities might be susceptible to similar basin amplification effects. Physics-based simulations in 3D crustal structure can be used to model and anticipate those effects, but they rely on our knowledge of the complexity of the medium. We propose a parallel approach to validate ground motion simulations using the ambient seismic field. We compute the Earth's impulse response combining the ambient seismic field and coda-wave enforcing causality and symmetry constraints. We correct the surface impulse responses to account for the source depth, mechanism and duration using a 1D approximation of the local surface-wave excitation. We call the new responses virtual earthquakes. We validate the ground motion predicted from the virtual earthquakes against moderate earthquakes in southern California. We then combine temporary seismic stations on the southern San Andreas Fault and extend the point source approximation of the Virtual Earthquake Approach to model finite kinematic ruptures. We confirm the coupling between source directivity and amplification in downtown Los Angeles seen in simulations.

Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations

DOE PAGES

Li, Zan; Millan, Robyn M.; Hudson, Mary K.; ...

2014-12-23

Electromagnetic ion cyclotron (EMIC) waves were observed at multiple observatory locations for several hours on 17 January 2013. During the wave activity period, a duskside relativistic electron precipitation (REP) event was observed by one of the Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) balloons and was magnetically mapped close to Geostationary Operational Environmental Satellite (GOES) 13. We simulate the relativistic electron pitch angle diffusion caused by gyroresonant interactions with EMIC waves using wave and particle data measured by multiple instruments on board GOES 13 and the Van Allen Probes. We show that the count rate, the energy distribution,more » and the time variation of the simulated precipitation all agree very well with the balloon observations, suggesting that EMIC wave scattering was likely the cause for the precipitation event. The event reported here is the first balloon REP event with closely conjugate EMIC wave observations, and our study employs the most detailed quantitative analysis on the link of EMIC waves with observed REP to date.« less

Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zan; Millan, Robyn M.; Hudson, Mary K.

Electromagnetic ion cyclotron (EMIC) waves were observed at multiple observatory locations for several hours on 17 January 2013. During the wave activity period, a duskside relativistic electron precipitation (REP) event was observed by one of the Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) balloons and was magnetically mapped close to Geostationary Operational Environmental Satellite (GOES) 13. We simulate the relativistic electron pitch angle diffusion caused by gyroresonant interactions with EMIC waves using wave and particle data measured by multiple instruments on board GOES 13 and the Van Allen Probes. We show that the count rate, the energy distribution,more » and the time variation of the simulated precipitation all agree very well with the balloon observations, suggesting that EMIC wave scattering was likely the cause for the precipitation event. The event reported here is the first balloon REP event with closely conjugate EMIC wave observations, and our study employs the most detailed quantitative analysis on the link of EMIC waves with observed REP to date.« less

Significant Variation of Post-critical SsPmp Amplitude as a Result of Variation in Near-surface Velocity: Observations from the Yellowknife Array

NASA Astrophysics Data System (ADS)

Ferragut, G.; Liu, T.; Klemperer, S. L.

2017-12-01

In recent years Virtual Deep Seismic Sounding (VDSS) emerged as a novel method to image the Moho, which uses the post-critical reflection P waves at the Moho generated by teleseismic S waves at the free surface near the receivers (SsPmp). However, observed SsPmp sometimes have significantly lower amplitude than predicted, raising doubts among the seismic community on the theoretical basis of the method. With over two decades of continuous digital broadband records and major subduction zones in the range of 30-50 degrees, the Yellowknife Array in northern Canada provides a rich opportunity for observation of post-critical SsPmp. We analyze S wave coda of events with epicenter distances of 30-50°, and pay special attention to earthquakes in a narrow azimuth range that ­­­encompasses the Kamchatka Peninsula. Among 21 events with strong direct S energy on the radial components, we observe significant variation of SsPmp energy. After associating the SsPmp energy with the virtual source location of each event, we observe a general trend of decreasing SsPmp energy from NE to SW. As the trend coincides with the transition from exposed basement of the Slave Craton to Paleozoic platform covered by Phanerozoic sediment, we interpret the decreasing SsPmp energy as a result of lower S velocity at the virtual sources, which reduces S-to-P reflection coefficients. We plan to include more events from the Aleutian Islands, the virtual sources of which are primarily located in the Paleozoic platform. This will allow us to further investigate the relationship between SsPmp amplitude and near-surface velocity.

First Light for ASTROVIRTEL Project

NASA Astrophysics Data System (ADS)

2000-04-01

Astronomical data archives increasingly resemble virtual gold mines of information. A new project, known as ASTROVIRTEL aims to exploit these astronomical treasure troves by allowing scientists to use the archives as virtual telescopes. The competition for observing time on large space- and ground-based observatories such as the ESA/NASA Hubble Space Telescope and the ESO Very Large Telescope (VLT) is intense. On average, less than a quarter of applications for observing time are successful. The fortunate scientist who obtains observing time usually has one year of so-called proprietary time to work with the data before they are made publicly accessible and can be used by other astronomers. Precious data from these large research facilities retain their value far beyond their first birthday and may still be useful decades after they were first collected. The enormous quantity of valuable astronomical data now stored in the archives of the European Southern Observatory (ESO) and the Space Telescope-European Coordinating Facility (ST-ECF) is increasingly attracting the attention of astronomers. Scientists are aware that one set of observations can serve many different scientific purposes, including some that were not considered at all when the observations were first made. Data archives as "gold mines" for research [ASTROVIRTEL Logo; JPEG - 184 k] Astronomical data archives increasingly resemble virtual gold mines of information. A new project, known as ASTROVIRTEL or "Accessing Astronomical Archives as Virtual Telescopes" aims to exploit these astronomical treasure troves. It is supported by the European Commission (EC) within the "Access to Research Infrastructures" action under the "Improving Human Potential & the Socio-economic Knowledge Base" of the EC (under EU Fifth Framework Programme). ASTROVIRTEL has been established on behalf of the European Space Agency (ESA) and the European Southern Observatory (ESO) in response to rapid developments currently taking place in the fields of telescope and detector construction, computer hardware, data processing, archiving, and telescope operation. Nowadays astronomical telescopes can image increasingly large areas of the sky. They use more and more different instruments and are equipped with ever-larger detectors. The quantity of astronomical data collected is rising dramatically, generating a corresponding increase in potentially interesting research projects. These large collections of valuable data have led to the useful concept of "data mining", whereby large astronomical databases are exploited to support original research. However, it has become obvious that scientists need additional support to cope efficiently with the massive amounts of data available and so to exploit the true potential of the databases. The strengths of ASTROVIRTEL ASTROVIRTEL is the first virtual astronomical telescope dedicated to data mining. It is currently being established at the joint ESO/Space Telescope-European Coordinating Facility Archive in Garching (Germany). Scientists from EC member countries and associated states will be able to apply for support for a scientific project based on access to and analysis of data from the Hubble Space Telescope (HST), Very Large Telescope (VLT), New Technology Telescope (NTT), and Wide Field Imager (WFI) archives, as well as a number of other related archives, including the Infrared Space Observatory (ISO) archive. Scientists will be able to visit the archive site and collaborate with the archive specialists there. Special software tools that incorporate advanced methods for exploring the enormous quantities of information available will be developed. Statements The project co-ordinator, Piero Benvenuti , Head of ST-ECF, elaborates on the advantages of ASTROVIRTEL: "The observations by the ESA/NASA Hubble Space Telescope and, more recently, by the ESO Very Large Telescope, have already been made available on-line to the astronomical community, once the proprietary period of one year has elapsed. ASTROVIRTEL is different, in that astronomers are now invited to regard the archive as an "observatory" in its own right: a facility that, when properly used, may provide an answer to their specific scientific questions. The architecture of the archives as well as their suite of software tools may have to evolve to respond to the new demand. ASTROVIRTEL will try to drive this evolution on the basis of the scientific needs of its users." Peter Quinn , the Head of ESO's Data Management and Operations Division, is of the same opinion: "The ESO/HST Archive Facility at ESO Headquarters in Garching is currently the most rapidly growing astronomical archive resource in the world. This archive is projected to contain more than 100 Terabytes (100,000,000,000,000 bytes) of data within the next four years. The software and hardware technologies for the archive will be jointly developed and operated by ESA and ESO staff and will be common to both HST and ESO data archives. The ASTROVIRTEL project will provide us with real examples of scientific research programs that will push the capabilities of the archive and allow us to identify and develop new software tools for data mining. The growing archive facility will provide the European astronomical community with new digital windows on the Universe." Note [1] This is a joint Press Release by the European Southern Observatory (ESO) and the Space Telescope European Coordinating Facility (ST-ECF). Additional information More information about ASTROVIRTEL can be found at the dedicated website at: http://www.stecf.org/astrovirtel The European Southern Observatory (ESO) is an intergovernmental organisation, supported by eight European countries: Belgium, Denmark, France, Germany, Italy, The Netherlands, Sweden and Switzerland. The European Space Agency is an intergovernmental organisation supported by 15 European countries: Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. The Space Telescope European Coordinating Facility (ST-ECF) is a co-operation between the European Space Agency and the European Southern Observatory. The Hubble Space Telescope (HST) is a project of international co-operation between NASA and ESA.

Magnetic Black Hole Waves

NASA Image and Video Library

2015-07-09

This cartoon shows how magnetic waves, called Alfvén S-waves, propagate outward from the base of black hole jets. The jet is a flow of charged particles, called a plasma, which is launched by a black hole. The jet has a helical magnetic field (yellow coil) permeating the plasma. The waves then travel along the jet, in the direction of the plasma flow, but at a velocity determined by both the jet's magnetic properties and the plasma flow speed. The BL Lac jet examined in a new study is several light-years long, and the wave speed is about 98 percent the speed of light. Fast-moving magnetic waves emanating from a distant supermassive black hole undulate like a whip whose handle is being shaken by a giant hand, according to a study using data from the National Radio Astronomy Observatory's Very Long Baseline Array. Scientists used this instrument to explore the galaxy/black hole system known as BL Lacertae (BL Lac) in high resolution. http://photojournal.jpl.nasa.gov/catalog/PIA19822

New Constraints on Upper Mantle Structure Underlying the Diamondiferous Central Slave Craton, Canada, from Teleseismic Body Wave Tomography

NASA Astrophysics Data System (ADS)

Esteve, C.; Schaeffer, A. J.; Audet, P.

2017-12-01

Over the past number of decades, the Slave Craton (Canada) has been extensively studied for its diamondiferous kimberlites. Not only are diamonds a valuable resource, but their kimberlitic host rocks provide an otherwise unique direct source of information on the deep upper mantle (and potentially transition zone). Many of the Canadian Diamond mines are located within the Slave Craton. As a result of the propensity for diamondiferous kimberlites, it is imperative to probe the deep mantle structure beneath the Slave Craton. This work is further motivated by the increase in high-quality broadband seismic data across the Northern Canadian Cordillera over the past decade. To this end we have generated a P and S body wave tomography model of the Slave Craton and its surroundings. Furthermore, tomographic inversion techniques are growing ever more capable of producing high resolution Earth models which capture detailed structure and dynamics across a range of scale lengths. Here, we present preliminary results on the structure of the upper mantle underlying the Slave Craton. These results are generated using data from eight different seismic networks such as the Canadian National Seismic Network (CNSN), Yukon Northwest Seismic Network (YNSN), older Portable Observatories for Lithospheric Analysis and Reseach Investigating Seismicity (POLARIS), Regional Alberta Observatory for Earthquake Studies Network (RV), USArray Transportable Array (TA), older Canadian Northwest Experiment (CANOE), Batholith Broadband (XY) and the Yukon Observatory (YO). This regional model brings new insights about the upper mantle structure beneath the Slave Craton, Canada.

Formation of artificial plasma disturbances in the lower ionosphere

NASA Astrophysics Data System (ADS)

Bakhmet'eva, N. V.; Frolov, V. L.; Vyakhirev, V. D.; Kalinina, E. E.; Bolotin, I. A.; Akchurin, A. D.; Zykov, E. Yu.

2012-06-01

We present the results of experiments on sounding the disturbed ionospheric region produced by the high-power RF radiation of the "Sura" heating facility, which were performed simultaneously at two observation points. One point is located on the territory of the heating facility the other, and the other, at the observatory of Kazan State University (the "Observatory" point) in 170 km to the East from the facility. The experiments were aimed at studying the mechanism of formation of artificial disturbances in the lower ionosphere in the case of reflection of a high-power wave in the F region and determining the parameters of the signals of backscattering from artificial electron density irregularities which are formed as a result of ionospheric perturbations. The ionosphere was modified by a high-power RF O-mode wave, which was emitted by the transmitters of the "Sura" facility, in sessions several seconds or minutes long. The disturbed region was sounded using the vertical-sounding technique at the "Vasil'sursk" laboratory by the partial-reflection facility at a frequency of 2.95 MHz, and by the modified ionospheric station "Tsiklon" at ten frequencies ranged from 2 to 6.5 MHz at the "Observatory" point. At the same time, vertical-sounding ionograms were recorded in the usual regime. At the reception points, simultaneous changes in the amplitudes of the vertical-sounding signals and the aspect backscattering signals were recorded. These records correlate with the periods of operation of the heating facility. The characteristics and dynamics of the signals are discussed.

Progressive Research and Outreach at the WestRock Observatory

NASA Astrophysics Data System (ADS)

Brown, Johnny Eugene; Lantz Caughey, Austin; O'Keeffe, Brendon; Johnson, Michael; Murphy Williams, Rosa Nina

2016-01-01

The WestRock Observatory (WRO), located in Columbus State University's Coca-Cola Space Science Center (CCSSC), is dedicated to education and research in astronomy through hands-on engagement and public participation. The WRO has recently received funding to upgrade the PlaneWave CDK 24-inch Corrected Dall-Kirkham Astrograph telescope. Recent additions to the telescope include an all-new Apogee Alta F16 CCD camera complete with a filter wheel (with narrowband and broadband filters) and a Minor Planet Center Observatory Code (W22). These new upgrades have allowed Astrophysics students to conduct unique research ranging from high precision minor planet astrometry, to broad- and narrow-band imaging of nebulae, to light curve analysis for variable star photometry. These new endeavours, in conjunction with an existing suite of Solar telescopes, gives the WRO the ability to live-stream solar and night-time observing. These streams are available both online and through interactive displays at the CCSSC making the WRO an educational outreach program for a worldwide public audience and a growing astronomical community.Current funding is allowing students to get even more research experience than previously attainable further enabling the expansion of our publicly available gallery of nebula and galaxy images. Support and funding for the acquirement,installation, and upgrading of the new PlaneWave CDK24 has been provided by the International Museum and Library Services via the Museums for America Award Additionally, individual NASA Space Grant Scholarships have helped to secure a number of student interns partially responsible for recent improvements.

(abstract) Dynamics of Meteor Trails Deposited in the Equatorial Electrojet

NASA Technical Reports Server (NTRS)

Chapin, Elaine; Kudeki, Erhan

1996-01-01

Previously we reported that the meteor echoes detected at the Jicamarca Radio Observatory exhibit some unusual properties. In summary, the echo durations are very long ..., radio wave scattering is non-specular ..., and the doppler spectra of the scattered signals contain components that are red-shifted ... immediately after the onset of the echoes.

Analysis of the Pendular and Pitch Motions of a Driven Three-Dimensional Pendulum

ERIC Educational Resources Information Center

Findley, T.; Yoshida, S.; Norwood, D. P.

2007-01-01

A three-dimensional pendulum, modelled after the Laser Interferometer Gravitational-Wave Observatory's suspended optics, was constructed to investigate the pendulum's dynamics due to suspension point motion. In particular, we were interested in studying the pendular-pitch energy coupling. Determination of the pendular's Q value (the quality factor…

Solar Dynamics Observatory Lessons Learned

NASA Technical Reports Server (NTRS)

Rivera, Rachel; Uhl, Andrew; Secunda, Mark

2010-01-01

Mission is to study how solar activity is created and how space weather results from that activity. Atmospheric Imaging Assembly (AIA): High Resolution Images of 10 wavelengths every 10 seconds. Extreme Ultraviolet Variability Experiment (EVE): Measure Sun's brightness in EUV. Helioseismic and Magnetic Imager (HMI): Measures Doppler shift to study waves of the Sun. Launched February 11, 2010.

Analysis of Gravitational Signals from Core-Collapse Supernovae (CCSNe) using MatLab

NASA Astrophysics Data System (ADS)

Frere, Noah; Mezzacappa, Anthony; Yakunin, Konstantin

2017-01-01

When a massive star runs out of fuel, it collapses under its own weight and rebounds in a powerful supernova explosion, sending, among other things, ripples through space-time, known as gravitational waves (GWs). GWs can be detected by earth-based observatories, such as the Laser Interferometer Gravitational-Wave Observatory (LIGO). Observers must compare the data from GW detectors with theoretical waveforms in order to confirm that the detection of a GW signal from a particular source has occurred. GW predictions for core collapse supernovae (CCSNe) rely on computer simulations. The UTK/ORNL astrophysics group has performed such simulations. Here, I analyze the resulting waveforms, using Matlab, to generate their Fourier transforms, short-time Fourier transforms, energy spectra, evolution of frequencies, and frequency maxima. One product will be a Matlab interface for analyzing and comparing GW predictions based on data from future simulations. This interface will make it easier to analyze waveforms and to share the results with the GW astrophysics community. Funding provided by Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200, USA.

Enhancing AstroInformatics and Science Discovery from Data in Journal Articles

NASA Astrophysics Data System (ADS)

Mazzarella, Joseph

2011-05-01

Traditional methods of publishing scientific data and metadata in journal articles are in need of major upgrades to reach the full potential of astronomical databases and astroinformatics techniques to facilitate semi-automated, and eventually autonomous, methods of science discovery. I will review a growing collaboration involving the NASA/IPAC Extragalactic Database (NED), the Astrophysics Data System (ADS), the Virtual Astronomical Observatory (VAO), the AAS Journals and IOP, and the Data Conservancy that is aimed toward transforming the methodology used to publish, capture and link data associated with astrophysics journal articles. We are planning a web-based workflow to assist astronomers during the publication of journal articles. The primary goals are to facilitate the application of structure and standards to (meta)data, reduce errors, remove ambiguities in the identification of astrophysical objects and regions of sky, capture and preserve the images and spectral data files used to make plots, and accelerate the ingestion of the data into relevant repositories, search engines and integration services. The outcome of this community wide effort will address a recent public policy mandate to publish scientific data in open formats to allow reproducibility of results and to facilitate new discoveries. Equally important, this work has the potential to usher in a new wave of science discovery based on seamless connectivity between data relationships that are continuously growing in size and complexity, and increasingly sophisticated data visualization and analysis applications.

Study of the characteristics of seismic signals generated by natural and cultural phenomena. [such as earthquakes, sonic booms, and nuclear explosions

NASA Technical Reports Server (NTRS)

Goforth, T. T.; Rasmussen, R. K.

1974-01-01

Seismic data recorded at the Tonto Forest Seismological Observatory in Arizona and the Uinta Basin Seismological Observatory in Utah were used to compare the frequency of occurrence, severity, and spectral content of ground motions resulting from earthquakes, and other natural and man-made sources with the motions generated by sonic booms. A search of data recorded at the two observatories yielded a classification of over 180,000 earthquake phase arrivals on the basis of frequency of occurrence versus maximum ground velocity. The majority of the large ground velocities were produced by seismic surface waves from moderate to large earthquakes in the western United States, and particularly along the Pacific Coast of the United States and northern Mexico. A visual analysis of raw film seismogram data over a 3-year period indicates that local and regional seismic events, including quarry blasts, are frequent in occurrence, but do not produce ground motions at the observatories comparable to either the large western United States earthquakes or to sonic booms. Seismic data from the Nevada Test Site nuclear blasts were used to derive magnitude-distance-sonic boom overpressure relations.

Cryogenically cooled low-noise amplifier for radio-astronomical observations and centimeter-wave deep-space communications systems

NASA Astrophysics Data System (ADS)

Vdovin, V. F.; Grachev, V. G.; Dryagin, S. Yu.; Eliseev, A. I.; Kamaletdinov, R. K.; Korotaev, D. V.; Lesnov, I. V.; Mansfeld, M. A.; Pevzner, E. L.; Perminov, V. G.; Pilipenko, A. M.; Sapozhnikov, B. D.; Saurin, V. P.

2016-01-01

We report a design solution for a highly reliable, low-noise and extremely efficient cryogenically cooled transmit/receive unit for a large antenna system meant for radio-astronomical observations and deep-space communications in the X band. We describe our design solution and the results of a series of laboratory and antenna tests carried out in order to investigate the properties of the cryogenically cooled low-noise amplifier developed. The transmit/receive unit designed for deep-space communications (Mars missions, radio observatories located at Lagrangian point L2, etc.) was used in practice for communication with live satellites including "Radioastron" observatory, which moves in a highly elliptical orbit.

Characteristics of an Imaging Polarimeter for the Powell Observatory

NASA Astrophysics Data System (ADS)

Hall, Shannon W.; Henson, Gary D.

2010-07-01

A dual-beam imaging polarimeter has been built for use on the 14-inch Schmidt-Cassegrain telescope at the ETSU Harry D. Powell Observatory. The polarimeter includes a rotating half-wave plate and a Wollaston prism to separate light into two orthogonal linearly polarized rays. A thermoelectrically cooled CCD camera is used to detect the modulated polarized light. We present here measurements of the polarization of polarimetric standard stars. By measuring unpolarized and polarized standard stars we are able to establish the instrumental polarization and the efficiency of the instrument. The polarimeter will initially be used as a dedicated instrument in an ongoing project to monitor the eclipsing binary star, Epsilon Aurigae.

LISA Pathfinder: A Mission Status

NASA Astrophysics Data System (ADS)

Hewitson, Martin; LISA Pathfinder Team Team

2016-03-01

On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

Performance of the Keck Observatory adaptive-optics system.

PubMed

van Dam, Marcos A; Le Mignant, David; Macintosh, Bruce A

2004-10-10

The adaptive-optics (AO) system at the W. M. Keck Observatory is characterized. We calculate the error budget of the Keck AO system operating in natural guide star mode with a near-infrared imaging camera. The measurement noise and bandwidth errors are obtained by modeling the control loops and recording residual centroids. Results of sky performance tests are presented: The AO system is shown to deliver images with average Strehl ratios of as much as 0.37 at 1.58 microm when a bright guide star is used and of 0.19 for a magnitude 12 star. The images are consistent with the predicted wave-front error based on our error budget estimates.

Information Content in Radio Waves: Student Investigations in Radio Science

NASA Astrophysics Data System (ADS)

Jacobs, K.; Scaduto, T.

2013-12-01

We describe an inquiry-based instructional unit on information content in radio waves, created in the summer of 2013 as part of a MIT Haystack Observatory (Westford, MA) NSF Research Experiences for Teachers (RET) program. This topic is current and highly relevant, addressing science and technical aspects from radio astronomy, geodesy, and atmospheric research areas as well as Next Generation Science Standards (NGSS). Projects and activities range from simple classroom demonstrations and group investigations, to long term research projects incorporating data acquisition from both student-built instrumentation as well as online databases. Each of the core lessons is applied to one of the primary research centers at Haystack through an inquiry project that builds on previously developed units through the MIT Haystack RET program. In radio astronomy, students investigate the application of a simple and inexpensive software defined radio chip (RTL-SDR) for use in systems implementing a small and very small radio telescope (SRT and VSRT). Both of these systems allow students to explore fundamental principles of radio waves and interferometry as applied to radio astronomy. In ionospheric research, students track solar storms from the initial coronal mass ejection (using Solar Dynamics Observatory images) to the resulting variability in total electron density concentrations using data from the community standard Madrigal distributed database system maintained by MIT Haystack. Finally, students get to explore very long-baseline interferometry as it is used in geodetic studies by measuring crustal plate displacements over time. Alignment to NextGen standards is provided for each lesson and activity with emphasis on HS-PS4 'Waves and Their Applications in Technologies for Information Transfer'.

The new geophysical observatory in Northern Caucasus (Elbrus volcanic area) and results of studies of ULF magnetic variations preceding strong geodynamic events

NASA Astrophysics Data System (ADS)

Sobissevitch, Leonid E.; Sobissevitch, Alex L.; Kanonidi, Konstantin Kh.; Filippov, Ivan N.

2010-05-01

The new geophysical observatory for fundamental scientific studies of geophysical processes in the Elbrus volcanic area (Northern Caucasus) has been organized recently as a result of merging of five geophysical laboratories positioned round the Elbrus volcano and equipped with modern geophysical instruments including broadband tri-axial seismometers, quartz tilt-meters, magnetic variometers, geo-acoustic sensors, hi-precision distributed thermal sensors, gravimeters, and network-enabled data acquisition systems with precise GPS-timing and integrated monitoring of auxiliary parameters (variations on ambient humidity, atmospheric pressure etc). Two laboratories are located in the horizontal 4.3 km deep tunnel drilled under the mount Andyrchi, about 20 km from the Elbrus volcano. Analysis of multi-parameter streams of experimental data allows one to study the structure of geophysical wave fields induced by earthquakes and regional catastrophic events (including snow avalanches). On the basis of continuous observations carried out since 2007 there have been determined anomalous wave forms in ULF geomagnetic variations preceding strong seismic events with magnitude 7 or more. Mentioned wave forms may be natively related to processes of evolution of dilatational structures in a domain of forthcoming seismic event. Specific patterns in anomalous ULF wave forms are distinguished for undersea earthquakes and for earthquakes responsible for triggering tsunami events. Thus, it is possible to consider development of a future technology to suggest the possible area and the time frame of such class of catastrophic events with additional reference to forecast information (including acoustic, hydro-acoustic and geo-acoustic) being concurrently analyzed.

Wave Field Synthesis of moving sources with arbitrary trajectory and velocity profile.

PubMed

Firtha, Gergely; Fiala, Péter

2017-08-01

The sound field synthesis of moving sound sources is of great importance when dynamic virtual sound scenes are to be reconstructed. Previous solutions considered only virtual sources moving uniformly along a straight trajectory, synthesized employing a linear loudspeaker array. This article presents the synthesis of point sources following an arbitrary trajectory. Under high-frequency assumptions 2.5D Wave Field Synthesis driving functions are derived for arbitrary shaped secondary source contours by adapting the stationary phase approximation to the dynamic description of sources in motion. It is explained how a referencing function should be chosen in order to optimize the amplitude of synthesis on an arbitrary receiver curve. Finally, a finite difference implementation scheme is considered, making the presented approach suitable for real-time applications.