Gravitational Waves: A New Observational Window

Science.gov (United States)

Camp, Jordan B.

2010-01-01

The era of gravitational wave astronomy is rapidly approaching, with a likely start date around the middle of this decade ' Gravitational waves, emitted by accelerated motions of very massive objects, provide detailed information about strong-field gravity and its sources, including black holes and neutron stars, that electromagnetic probes cannot access. In this talk I will discuss the anticipated sources and the status of the extremely sensitive detectors (both ground and space based) that will make gravitational wave detections possible. As ground based detectors are now taking data, I will show some initial science results related to measured upper limits on gravitational wave signals. Finally Z will describe new directions including advanced detectors and joint efforts with other fields of astronomy.

Gravitational-Wave Astronomy

Science.gov (United States)

Kelly, Bernard J.

2010-01-01

Einstein's General Theory of Relativity is our best classical description of gravity, and informs modern astronomy and astrophysics at all scales: stellar, galactic, and cosmological. Among its surprising predictions is the existence of gravitational waves -- ripples in space-time that carry energy and momentum away from strongly interacting gravitating sources. In my talk, I will give an overview of the properties of this radiation, recent breakthroughs in computational physics allowing us to calculate the waveforms from galactic mergers, and the prospect of direct observation with interferometric detectors such as LIGO and LISA.

The ground based plan

International Nuclear Information System (INIS)

1989-01-01

The paper presents a report of ''The Ground Based Plan'' of the United Kingdom Science and Engineering Research Council. The ground based plan is a plan for research in astronomy and planetary science by ground based techniques. The contents of the report contains a description of:- the scientific objectives and technical requirements (the basis for the Plan), the present organisation and funding for the ground based programme, the Plan, the main scientific features and the further objectives of the Plan. (U.K.)

Gravitational Wave Astrophysics: Opening the New Frontier

Science.gov (United States)

Centrella, Joan

2012-01-01

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

Status of advanced ground-based laser interferometers for gravitational-wave detection

Science.gov (United States)

Dooley, K. L.; Akutsu, T.; Dwyer, S.; Puppo, P.

2015-05-01

Ground-based laser interferometers for gravitational-wave (GW) detection were first constructed starting 20 years ago and as of 2010 collection of several years’ worth of science data at initial design sensitivities was completed. Upgrades to the initial detectors together with construction of brand new detectors are ongoing and feature advanced technologies to improve the sensitivity to GWs. This conference proceeding provides an overview of the common design features of ground-based laser interferometric GW detectors and establishes the context for the status updates of each of the four gravitational-wave detectors around the world: Advanced LIGO, Advanced Virgo, GEO 600 and KAGRA.

Multi-Messenger Astronomy with Gravitational Waves

Indian Academy of Sciences (India)

Sound + images show Bailey was out in the India-Australia match on 12 Jan 2016. Image credit: Rediff / Fox news / Twitter. Page 10. Electromagnetic follow up: the Indian context. Page 11. Multi-Messenger Astronomy with Gravitational Waves | LIGO-G1601377-v2. Varun Bhalerao (IUCAA) | 1 July 2016. 11. 20 – 60 keV:.

Gravitational Waves and Multi-Messenger Astronomy

Science.gov (United States)

Centrella, Joan M.

2010-01-01

Gravitational waves are produced by a wide variety of sources throughout the cosmos, including the mergers of black hole and neutron star binaries/compact objects spiraling into central black holes in galactic nuclei, close compact binaries/and phase transitions and quantum fluctuations in the early universe. Observing these signals can bring new, and often very precise, information about their sources across vast stretches of cosmic time. In this talk we will focus on thee opening of this gravitational-wave window on the universe, highlighting new opportunities for discovery and multi-messenger astronomy.

Astronomy's New Messengers: A traveling exhibit on gravitational-wave physics

International Nuclear Information System (INIS)

Cavaglia, Marco; Hendry, Martin; Marka, Szabolcs; Reitze, David H; Riles, Keith

2010-01-01

The Laser Interferometer Gravitational-wave Observatory exhibit Astronomy's New Messengers: Listening to the Universe with Gravitational Waves is traveling to colleges, universities, museums and other public institutions throughout the United States. Astronomy's New Messengers primarily communicates with an adolescent and young adult audience, potentially inspiring them into the field of science. Acknowledging that this audience is traditionally a difficult one to attract, the exhibit publicly announces itself in a charismatic fashion to reach its principal goals of broadening the community of people interested in science and encouraging interest in science among young people.

Status of advanced ground-based laser interferometers for gravitational-wave detection

International Nuclear Information System (INIS)

Dooley, K L; Akutsu, T; Dwyer, S; Puppo, P

2015-01-01

Ground-based laser interferometers for gravitational-wave (GW) detection were first constructed starting 20 years ago and as of 2010 collection of several years’ worth of science data at initial design sensitivities was completed. Upgrades to the initial detectors together with construction of brand new detectors are ongoing and feature advanced technologies to improve the sensitivity to GWs. This conference proceeding provides an overview of the common design features of ground-based laser interferometric GW detectors and establishes the context for the status updates of each of the four gravitational-wave detectors around the world: Advanced LIGO, Advanced Virgo, GEO 600 and KAGRA. (paper)

White Paper on the Status and Future of Ground-based Gamma-Ray Astronomy - Extragalactic Science Working Group

Science.gov (United States)

Krawczynski, H.; Coppi, P.; Dermer, C.; Dwek, E.; Georganopoulos, M.; Horan, D.; Jones, T.; Krennrich, F.; Mukherjee, R.; Perlman, E.; Vassiliev, V.

2007-04-01

In fall 2006, the Division of Astrophysics of the American Physical Society requested a white paper about the status and future of ground based gamma-ray astronomy. The white paper will largely be written in the year 2007. Interested scientists are invited to join the science working groups. In this contribution, we will report on some preliminary results of the extragalactic science working group. We will discuss the potential of future ground based gamma-ray experiments to elucidate how supermassive black holes accrete matter, form jets, and accelerate particles, and to study in detail the acceleration and propagation of cosmic rays in extragalactic systems like infrared galaxies and galaxy clusters. Furthermore, we discuss avenues to constrain the spectrum of the extragalactic infrared to optical background radiation, and to measure the extragalactic magnetic fields based on gamma-ray observations. Eventually, we discuss the potential of ground based experiments for conducting gamma-ray source surveys. More information about the white paper can be found at: http://cherenkov.physics.iastate.edu/wp/

The Future of Space Astronomy.

Science.gov (United States)

Field, George B.

1984-01-01

Discusses various aspects of space astronomy, considering advantages, the space telescope and ground-based astronomy, an orbiting astrophysics facility, solar physics, and other areas. Indicates that earth-based astronomy will continue to be carried out there and space astronomy will be limited to observations that can be carried out only from…

Streamlining Collaboration for the Gravitational-wave Astronomy Community

Science.gov (United States)

Koranda, S.

2016-12-01

In the morning hours of September 14, 2015 the LaserInterferometer Gravitational-wave Observatory (LIGO) directlydetected gravitational waves from inspiraling and coalescingblack holes, confirming a major prediction of AlbertEinstein's general theory of relativity and beginning the eraof gravitational-wave astronomy. With the LIGO detectors in the United States, the Virgo andGEO detectors in Europe, and the KAGRA detector in Japan thegravitational-wave astrononmy community is opening a newwindow on our Universe. Realizing the full science potentialof LIGO and the other interferometers requires globalcollaboration not only within the gravitational-wave astronomycommunity but also with the astronomers and astrophysicists acrossmultipe disciplines working to realize and leverage the powerof multi-messenger astronomy. Enabling thousands of researchers from around the world andacross multiple projects to efficiently collaborate, share,and analyze data and provide streamlined access to services,computing, and tools requires new and scalable approaches toidentity and access management (IAM). We will discuss LIGO'sIAM journey that began in 2007 and how today LIGO leveragesinternal identity federations like InCommon and eduGAIN toprovide scalable and managed access for the gravitational-waveastronomy community. We will discuss the steps both largeand small research organizations and projects take as theirIAM infrastructure matures from ad-hoc silos of independent services to fully integrated and federated services thatstreamline collaboration so that scientists can focus onresearch and not managing passwords.

Transient multimessenger astronomy with gravitational waves

International Nuclear Information System (INIS)

Marka, S

2011-01-01

Comprehensive multimessenger astronomy with gravitational waves is a pioneering field bringing us interesting results and presenting us with exciting challenges for the future. During the era of the operation of advanced interferometric gravitational wave detectors, we will have the opportunity to investigate sources of gravitational waves that are also expected to be observable through other messengers, such as gamma rays, x-rays, optical, radio, and/or neutrino emission. Multimessenger searches for gravitational waves with the LIGO-GEO600-Virgo interferometer network have already produced insights on cosmic events and it is expected that the simultaneous observation of electromagnetic or neutrino emission could be a crucial aspect for the first direct detection of gravitational waves in the future. Trigger time, direction and expected frequency range enhances our ability to search for gravitational wave signatures with amplitudes closer to the noise floor of the detector. Furthermore, multimessenger observations will enable the extraction of otherwise unaccessible scientific insight. We summarize the status of transient multimessenger detection efforts as well as mention some of the open questions that might be resolved by advanced or third generation gravitational wave detector networks.

High energy astrophysics with ground-based gamma ray detectors

International Nuclear Information System (INIS)

Aharonian, F; Buckley, J; Kifune, T; Sinnis, G

2008-01-01

Recent advances in ground-based gamma ray astronomy have led to the discovery of more than 70 sources of very high energy (E γ ≥ 100 GeV) gamma rays, falling into a number of source populations including pulsar wind nebulae, shell type supernova remnants, Wolf-Rayet stars, giant molecular clouds, binary systems, the Galactic Center, active galactic nuclei and 'dark' (yet unidentified) galactic objects. We summarize the history of TeV gamma ray astronomy up to the current status of the field including a description of experimental techniques and highlight recent astrophysical results. We also discuss the potential of ground-based gamma ray astronomy for future discoveries and describe possible directions for future instrumental developments

Research on Ground Motion Metal Target Based on Rocket Projectile by Using Millimeter Wave Radiometer Technology

Directory of Open Access Journals (Sweden)

Zhang Dongyang

2014-06-01

Full Text Available How to detect the ground motion metal target effectively is an important guarantee for precision strike in the process of Rocket Projectile flight. Accordingly and in view of the millimeter- wave radiation characteristic of the ground motion metal target, a mathematical model was established based on Rocket Projectile about millimeter-wave detection to the ground motion metal target. Through changing various parameters in the process of Rocket Projectile flight, the detection model was studied by simulation. The parameters variation and effective range of millimeter wave radiometer were obtained in the process of rotation and horizontal flight. So a certain theoretical basis was formed for the precision strike to the ground motion metal target.

Division B Commission 40: Radio Astronomy

NARCIS (Netherlands)

Chapman, Jessica M.; Giovaninni, Gabriele; Taylor, Russell; Carilli, Christopher; Hills, Richard; Hirabayashi, Hisashi; Jonas, Justin L.; Lazio, Joseph; Morganti, Raffaella; Nan, Rendong; Rubio, Monica; Shastri, Prjaval; Kellermann, Ken; Ekers, Ronald; Ohishi, Masatoshi

2016-01-01

IAU Commission 40 for Radio Astronomy (hereafter C40) brought together scientists and engineers who carry out observational and theoretical research in radio astronomy and who develop and operate the ground and space-based radio astronomy facilities and instrumentation. As of June 2015, the

Extragalactic infrared astronomy

International Nuclear Information System (INIS)

Gondhalekar, P.M.

1985-05-01

The paper concerns the field of Extragalactic Infrared Astronomy, discussed at the Fourth RAL Workshop on Astronomy and Astrophysics. Fifteen papers were presented on infrared emission from extragalactic objects. Both ground-(and aircraft-) based and IRAS infrared data were reviewed. The topics covered star formation in galaxies, active galactic nuclei and cosmology. (U.K.)

Ground penetrating radar antenna measurements based on plane-wave expansions

DEFF Research Database (Denmark)

Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

2005-01-01

The plane-wave transmitting spectrum of the system consisting of the ground penetrating radar (GPR) antenna and the air-soil interface is measured using a loop buried in the soil. The plane-wave spectrum is used to determine various parameters characterizing the radiation of the GPR antenna...

Quantum metrology for gravitational wave astronomy.

Science.gov (United States)

Schnabel, Roman; Mavalvala, Nergis; McClelland, David E; Lam, Ping K

2010-11-16

Einstein's general theory of relativity predicts that accelerating mass distributions produce gravitational radiation, analogous to electromagnetic radiation from accelerating charges. These gravitational waves (GWs) have not been directly detected to date, but are expected to open a new window to the Universe once the detectors, kilometre-scale laser interferometers measuring the distance between quasi-free-falling mirrors, have achieved adequate sensitivity. Recent advances in quantum metrology may now contribute to provide the required sensitivity boost. The so-called squeezed light is able to quantum entangle the high-power laser fields in the interferometer arms, and could have a key role in the realization of GW astronomy.

Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

Science.gov (United States)

Ando, Shin'ichiro; Baret, Bruny; Bartos, Imre; Bouhou, Boutayeb; Chassande-Mottin, Eric; Corsi, Alessandra; Di Palma, Irene; Dietz, Alexander; Donzaud, Corinne; Eichler, David; Finley, Chad; Guetta, Dafne; Halzen, Francis; Jones, Gareth; Kandhasamy, Shivaraj; Kotake, Kei; Kouchner, Antoine; Mandic, Vuk; Márka, Szabolcs; Márka, Zsuzsa; Moscoso, Luciano; Papa, Maria Alessandra; Piran, Tsvi; Pradier, Thierry; Romero, Gustavo E.; Sutton, Patrick; Thrane, Eric; Van Elewyck, Véronique; Waxman, Eli

2013-10-01

Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic messengers that may escape much denser media than photons. They travel unaffected over cosmological distances, carrying information from the inner regions of the astrophysical engines from which they are emitted (and from which photons and charged cosmic rays cannot reach us). For the same reasons, such messengers could also reveal new, hidden sources that have not been observed by conventional photon-based astronomy. Coincident observation of GWs and HENs may thus play a critical role in multimessenger astronomy. This is particularly true at the present time owing to the advent of a new generation of dedicated detectors: the neutrino telescopes IceCube at the South Pole and ANTARES in the Mediterranean Sea, as well as the GW interferometers Virgo in Italy and LIGO in the United States. Starting from 2007, several periods of concomitant data taking involving these detectors have been conducted. More joint data sets are expected with the next generation of advanced detectors that are to be operational by 2015, with other detectors, such as KAGRA in Japan, joining in the future. Combining information from these independent detectors can provide original ways of constraining the physical processes driving the sources and also help confirm the astrophysical origin of a GW or HEN signal in case of coincident observation. Given the complexity of the instruments, a successful joint analysis of this combined GW and HEN observational data set will be possible only if the expertise and knowledge of the data is shared between the two communities. This Colloquium aims at providing an overview of both theoretical and experimental state of the art and perspectives for GW and HEN

Multimessenger astronomy with pulsar timing and X-ray observations of massive black hole binaries

Science.gov (United States)

Sesana, A.; Roedig, C.; Reynolds, M. T.; Dotti, M.

2012-02-01

In the decade of the dawn of gravitational wave astronomy, the concept of multimessenger astronomy, combining gravitational wave signals to conventional electromagnetic observation, has attracted the attention of the astrophysical community. So far, most of the effort has been focused on ground- and space-based laser interferometer sources, with little attention devoted to the ongoing and upcoming pulsar timing arrays (PTAs). We argue in this paper that PTA sources, being very massive (>108 M⊙) cosmologically nearby (z 10-13 erg s-1 cm-2 will be in the reach of upcoming X-ray observatories; in the most optimistic case, a few of them may be already being observed by the MAXI detector placed on the International Space Station. Double relativistic Kα lines may be observable in a handful of low-redshift (z figures depend on the details of the adopted MBHB population and on the properties of the circumbinary discs, but the existence of a sizeable population of sources suitable to multimessenger astronomy is a robust prediction of our investigation.

Astrophysical Model Selection in Gravitational Wave Astronomy

Science.gov (United States)

Adams, Matthew R.; Cornish, Neil J.; Littenberg, Tyson B.

2012-01-01

Theoretical studies in gravitational wave astronomy have mostly focused on the information that can be extracted from individual detections, such as the mass of a binary system and its location in space. Here we consider how the information from multiple detections can be used to constrain astrophysical population models. This seemingly simple problem is made challenging by the high dimensionality and high degree of correlation in the parameter spaces that describe the signals, and by the complexity of the astrophysical models, which can also depend on a large number of parameters, some of which might not be directly constrained by the observations. We present a method for constraining population models using a hierarchical Bayesian modeling approach which simultaneously infers the source parameters and population model and provides the joint probability distributions for both. We illustrate this approach by considering the constraints that can be placed on population models for galactic white dwarf binaries using a future space-based gravitational wave detector. We find that a mission that is able to resolve approximately 5000 of the shortest period binaries will be able to constrain the population model parameters, including the chirp mass distribution and a characteristic galaxy disk radius to within a few percent. This compares favorably to existing bounds, where electromagnetic observations of stars in the galaxy constrain disk radii to within 20%.

Shear wave velocity-based evaluation and design of stone column improved ground for liquefaction mitigation

Science.gov (United States)

Zhou, Yanguo; Sun, Zhengbo; Chen, Jie; Chen, Yunmin; Chen, Renpeng

2017-04-01

The evaluation and design of stone column improvement ground for liquefaction mitigation is a challenging issue for the state of practice. In this paper, a shear wave velocity-based approach is proposed based on the well-defined correlations of liquefaction resistance (CRR)-shear wave velocity ( V s)-void ratio ( e) of sandy soils, and the values of parameters in this approach are recommended for preliminary design purpose when site specific values are not available. The detailed procedures of pre- and post-improvement liquefaction evaluations and stone column design are given. According to this approach, the required level of ground improvement will be met once the target V s of soil is raised high enough (i.e., no less than the critical velocity) to resist the given earthquake loading according to the CRR- V s relationship, and then this requirement is transferred to the control of target void ratio (i.e., the critical e) according to the V s- e relationship. As this approach relies on the densification of the surrounding soil instead of the whole improved ground and is conservative by nature, specific considerations of the densification mechanism and effect are given, and the effects of drainage and reinforcement of stone columns are also discussed. A case study of a thermal power plant in Indonesia is introduced, where the effectiveness of stone column improved ground was evaluated by the proposed V s-based method and compared with the SPT-based evaluation. This improved ground performed well and experienced no liquefaction during subsequent strong earthquakes.

Astronomy and astrophysics in the new millennium: Panel reports

National Research Council Canada - National Science Library

Astronomy and Astrophysics Survey Committee, Board on Physics and Astronomy, Space Studies Board, National Research Council

2001-01-01

In preparing the report, Astronomy and Astrophysics in the New Millenium , the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysic...

Astronomy and astrophysics with gravitational waves in the advanced detector era

International Nuclear Information System (INIS)

Weinstein, Alan J

2012-01-01

With the advanced gravitational wave detectors coming on line in the next 5 years, we expect to make the first detections of gravitational waves from astrophysical sources, and study the properties of the waves themselves as tests of general relativity. In addition, these gravitational waves will be powerful tools for the study of their astrophysical sources and source populations. They carry information that is quite complementary to what can be learned from electromagnetic or neutrino observations, probing the central gravitational engines that power the electromagnetic emissions at the outer layers of the source. Preparations are being made to enable near-simultaneous observations of both gravitational wave and electromagnetic observations of transient sources, using low-latency search pipelines and rapid sky localization. We will review the many opportunities for multi-messenger astronomy and astrophysics with gravitational waves enabled by the advanced detectors, and the preparations that are being made to quickly and fully exploit them. (paper)

The decade of discovery in astronomy and astrophysics

International Nuclear Information System (INIS)

Anon.

1991-01-01

The conference presents papers on recommended ground- and space-based initiatives for the 1990s. The need to restore the research infrastructure at the university level is addressed as well as ways of achieving a balanced space program. Consideration is also given to science opportunities, astronomy and the computer revolution, lunar astronomy, policy opportunities, and astronomy as a national asset

Black Hole Mergers, Gravitational Waves, and Multi-Messenger Astronomy

Science.gov (United States)

Centrella, Joan M.

2010-01-01

The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as the space-based LISA. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. Although numerical codes designed to simulate black hole mergers were plagued for many years by a host of instabilities, recent breakthroughs have conquered these problems and opened up this field dramatically. This talk will focus on the resulting gold rush of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, astrophysics, and testing general relativity.

Ground-based gamma-ray astronomy with Cherenkov telescopes

International Nuclear Information System (INIS)

Hinton, Jim

2009-01-01

Very high-energy (>100 GeV) γ-ray astronomy is emerging as an important discipline in both high-energy astrophysics and astro-particle physics. This field is currently dominated by imaging atmospheric-Cherenkov telescopes (IACTs) and arrays of these telescopes. Such arrays have achieved the best angular resolution and energy flux sensitivity in the γ-ray domain and are still far from the fundamental limits of the technique. Here, I will summarize some key aspects of this technique and go on to review the current status of the major instruments and to highlight selected recent results.

Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays

Directory of Open Access Journals (Sweden)

Nicolás Yunes

2013-11-01

Full Text Available This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein’s theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime. Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays.

Science.gov (United States)

Yunes, Nicolás; Siemens, Xavier

2013-01-01

This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein's theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime . Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

Precision engineering for astronomy: historical origins and the future revolution in ground-based astronomy.

Science.gov (United States)

Cunningham, Colin; Russell, Adrian

2012-08-28

Since the dawn of civilization, the human race has pushed technology to the limit to study the heavens in ever-increasing detail. As astronomical instruments have evolved from those built by Tycho Brahe in the sixteenth century, through Galileo and Newton in the seventeenth, to the present day, astronomers have made ever more precise measurements. To do this, they have pushed the art and science of precision engineering to extremes. Some of the critical steps are described in the evolution of precision engineering from the first telescopes to the modern generation telescopes and ultra-sensitive instruments that need a combination of precision manufacturing, metrology and accurate positioning systems. In the future, precision-engineered technologies such as those emerging from the photonics industries may enable future progress in enhancing the capabilities of instruments, while potentially reducing the size and cost. In the modern era, there has been a revolution in astronomy leading to ever-increasing light-gathering capability. Today, the European Southern Observatory (ESO) is at the forefront of this revolution, building observatories on the ground that are set to transform our view of the universe. At an elevation of 5000 m in the Atacama Desert of northern Chile, the Atacama Large Millimetre/submillimetre Array (ALMA) is nearing completion. The ALMA is the most powerful radio observatory ever and is being built by a global partnership from Europe, North America and East Asia. In the optical/infrared part of the spectrum, the latest project for ESO is even more ambitious: the European Extremely Large Telescope, a giant 40 m class telescope that will also be located in Chile and which will give the most detailed view of the universe so far.

Small Explorer project: Submillimeter Wave Astronomy Satellite (SWAS). Mission operations and data analysis plan

Science.gov (United States)

Melnick, Gary J.

1990-01-01

The Mission Operations and Data Analysis Plan is presented for the Submillimeter Wave Astronomy Satellite (SWAS) Project. It defines organizational responsibilities, discusses target selection and navigation, specifies instrument command and data requirements, defines data reduction and analysis hardware and software requirements, and discusses mission operations center staffing requirements.

Ground and Satellite Observations of ULF Waves Artificially Produced by HAARP

Science.gov (United States)

Chang, C.; Labenski, J.; Shroff, H.; Doxas, I.; Papadopoulos, D.; Milikh, G.; Parrot, M.

2008-12-01

Modulated ionospheric heating at ULF frequencies using the HAARP heater was performed from April 28 to May 3, 2008 (http://www.haarp.alaska.edu). Simultaneous ground-based ULF measurements were made locally at Gakona, AK and at Lake Ozette, WA that is 2000 km away. The ground-based results showed that ULF amplitudes measured at Gakona are mostly proportional to the electrojet strength above HAARP, indicating electrojet modulation to be the source of the local ULF waves. However, the timing of ULF events recorded at Lake Ozette did not correlated with the electrojet strength at Gakona, indicating that modulation of F region pressure is the more likely source for distant ULF waves. These observations are consistent with the theoretical understanding that ULF waves generated by current modulation are shear Alfven waves propagating along the magnetic field line, thus at high latitude their observations are limited to the vicinity of the heated spot. On the other hand, propagation of ULF waves at significant lateral distances requires generation of magnetosonic waves since they are the only mode that propagates isotropically and can thus couple efficiently in the Alfvenic duct. In addition to ground-based observations, the DEMETER satellite also provided space measurements of the heating effects during its passes over HAARP. The DEMETER results showed direct detection of HAARP ULF waves at 0.1 Hz. Moreover, density dips were observed every time HAARP was operated at CW mode, which provides clear evidence of duct formation by direct HF heating at F peak. Details of these results will be presented at the meeting. We would like to acknowledge the support provided by the HAARP facility during our ULF experiments.

Very high energy gamma-ray astronomy

International Nuclear Information System (INIS)

Weekes, T.C.

1988-01-01

Current interest in gamma-ray astronomy at energies above 100 GeV comes from the identification of Cygnus X-3 and other X-ray binaries as sources. In addition there are reports of emission from radio pulsars and a variety of other objects. The statistical significance of many of the observations is not high and many reported effects await confirmation, but there are a sufficient number of independent reports that very high energy gamma-ray astronomy must now be considered to have an observational basis. The observations are summarized with particular emphasis on those reported since 1980. The techniques used - the detection of small air showers using the secondary photons and particles at ground level - are unusual and are described. Future prospects for the field are discussed in relation to new ground-based experiments, satellite gamma-ray studies and proposed neutrino astronomy experiments. (orig.) With 296 refs

Assessing ground compaction via time lapse surface wave analysis

Czech Academy of Sciences Publication Activity Database

Dal Moro, Giancarlo; Al-Arifi, N.; Moustafa, S.S.R.

2016-01-01

Roč. 13, č. 3 (2016), s. 249-256 ISSN 1214-9705 Institutional support: RVO:67985891 Keywords : Full velocity spectrum (FVS) analysis * ground compaction * ground compaction * phase velocities * Rayleigh waves * seismic data inversion * surface wave dispersion * surface waves Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.699, year: 2016

The astronomy spacelab payloads study: executive volume. Interim report

International Nuclear Information System (INIS)

1975-07-01

The progress of the Astronomy Spacelab Payloads Project at the Goddard Space Flight Center is reported. Astronomical research in space, using the Spacelab in conjunction with the Space Shuttle, is described. The various fields of solar astronomy or solar physics, ultraviolet and optical astronomy, and high energy astrophysics are among the topics discussed. These fields include scientific studies of the Sun and its dynamical processes, of the stars in wavelength regions not accessible to ground based observations, and the exciting new fields of X-ray, gamma ray, and particle astronomy

Multisatellite and ground-based observations of transient ULF waves

International Nuclear Information System (INIS)

Potemra, T.A.; Zanetti, L.J.; Takahashi, K.; Erlandson, R.E.; Luehr, H.; Marklund, G.T.; Block, L.P.; Blomberg, L.G.; Lepping, R.P.

1989-01-01

A unique alignment of the Active Magnetospheric Particle Tracer Explorers (AMPTE) CCE and Viking satellites with respect to the EISCAT Magnetometer Cross has provided an opportunity to study transient ULF pulsations associated with variations in solar wind plasma density observed by the IMP 8 satellite. These observations were acquired during a relatively quiet period on April 24, 1986, during the Polar Region and Outer Magnetosphere International Study (PROMIS) period. An isolated 4-mHz (4-min period) pulsation was detected on the ground which was associated with transverse magnetic field oscillations observed by Viking at a ∼ 2-R E altitude above the auroral zone and by CCE at ∼ 8-R E in the equatorial plane on nearly the same flux tube. CCE detected a compressional oscillation in the magnetic field with twice the period (∼ 10 min) of the transverse waves, and with a waveform nearly identical to an isolated oscillation in the solar wind plasma density measured by IMP 8. The authors conclude that the isolated 10-min oscillation in solar wind plasma density produced magnetic field compression oscillations inside the magnetosphere at the same frequency which also enhanced resonant oscillations at approximately twice the frequency that were already present. The ground magnetic field variations are due to ionospheric Hall currents driven by the electric field of the standing Alfven waves. The time delay between surface and satellite data acquired at different local times supports the conclusion that the periodic solar wind density variation excites a tailward traveling large-scale magnetosphere wave train which excites local field line resonant oscillations. They conclude that these transient magnetic field variations are not associated with magnetic field reconnection or flux transfer events

Composite mirror facets for ground based gamma ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Brun, P.; Carton, P.-H.; Durand, D.; Glicenstein, J.-F.; Jeanney, C. [CEA, Irfu, Centre de Saclay, F-91191 Gif sur Yvette (France); Medina, M.C., E-mail: clementina@iar.unlp.edu.ar [CEA, Irfu, Centre de Saclay, F-91191 Gif sur Yvette (France); Micolon, P.; Peyaud, B. [CEA, Irfu, Centre de Saclay, F-91191 Gif sur Yvette (France)

2013-06-21

Composite mirrors for gamma-ray astronomy have been developed to fulfill the specifications required for the next generation of Cherenkov telescopes represented by CTA (Cherenkov Telescope Array). In addition to the basic requirements on focus and reflection efficiency, the mirrors have to be stiff, lightweight, durable and cost efficient. In this paper, the technology developed to produce such mirrors is described, as well as some tests that have been performed to validate them. It is shown that these mirrors comply with the needs of CTA, making them good candidates for use on a significant part of the array.

Future of Space Astronomy: A Global Road Map for the Next Decades

Science.gov (United States)

Ubertini, Pietro; Gehrels, Neil; Corbett, Ian; DeBernardis, Paolo; Machado, Marcos; Griffin, Matt; Hauser, Michael; Manchanda, Ravinder K.; Kawai, Nobuyuki; Zhang, Shuang-Nan;

Ionospheric wave and irregularity measurements using passive radio astronomy techniques

International Nuclear Information System (INIS)

Erickson, W.C.; Mahoney, M.J.; Jacobson, A.R.; Knowles, S.H.

1988-01-01

The observation of midlatitude structures using passive radio astronomy techniques is discussed, with particular attention being given to the low-frequency radio telescope at the Clark Lake Radio Observatory. The present telescope operates in the 10-125-MHz frequency range. Observations of the ionosphere at separations of a few kilometers to a few hundreds of kilometers by the lines of sight to sources are possible, allowing the determination of the amplitude, wavelength, direction of propagation, and propagation speed of ionospheric waves. Data are considered on large-scale ionospheric gradients and the two-dimensional shapes and sizes of ionospheric irregularities. 10 references

Light and lightened mirrors for astronomy

Science.gov (United States)

Fappani, Denis

2008-07-01

For ground-based astronomy, more and more large telescopes are emerging all around the world. Similarly to space borne telescopes, for which the use of lightened optics has always been a baseline for purpose of mass reduction of payloads, same kinds of lightened/light mirrors are then now more and more intensively used also for ground-based instrumentation for astronomy, requiring larger and larger components. Through several examples of typical past realizations (class 0.5m-1m) for different astronomical projects requiring light or lightened mirrors for different reasons (optimisation of mass and stiffness, reduction of thermal inertia, increasing of dynamic performance for fast scanning purpose,....), the presentation will point out issues for lightening design, manufacturing and control of such parts, as well as brief overview of the corresponding existing "state of the art" for these technologies in SESO.

Advancements in Kinetic Inductance Detector, Spectrometer, and Amplifier Technologies for Millimeter-Wave Astronomy

Science.gov (United States)

Che, George

The inductance of a conductor expresses its tendency to oppose a change in current flowing through it. For superconductors, in addition to the familiar magnetic inductance due to energy stored in the magnetic field generated by this current, kinetic inductance due to inertia of charge carriers is a significant and often dominant contribution to total inductance. Devices based on modifying the kinetic inductance of thin film superconductors have widespread application to millimeter-wave astronomy. Lithographically patterning such a film into a high quality factor resonator produces a high sensitivity photodetector known as a kinetic inductance detector (KID), which is sensitive to frequencies above the superconducting energy gap of the chosen material. Inherently multiplexable in the frequency domain and relatively simple to fabricate, KIDs pave the way to the large format focal plane array instruments necessary to conduct the next generation of cosmic microwave background (CMB), star formation, and galaxy evolution studies. In addition, non-linear kinetic inductance can be exploited to develop traveling wave kinetic inductance parametric amplifiers (TKIPs) based on superconducting delay lines to read out these instruments. I present my contributions to both large and small scale collaborative efforts to develop KID arrays, spectrometers integrated with KIDs, and TKIPs. I optimize a dual polarization TiN KID absorber for the next generation Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry, which is designed to investigate the role magnetic fields play in star formation. As part of an effort to demonstrate aluminum KIDs on sky for CMB polarimetry, I fabricate devices for three design variants. SuperSpec and WSpec are respectively the on-chip and waveguide implementations of a filter bank spectrometer concept designed for survey spectroscopy of high redshift galaxies. I provide a robust tool for characterizing the performance of all Super

Mathematics and Astronomy: Inquire Based Scientific Education at School

Science.gov (United States)

de Castro, Ana I. Gómez

2010-10-01

Mathematics is the language of science however, in secondary and high school education students are not made aware of the strong implications behind this statement. This is partially caused because mathematical training and the modelling of nature are not taught together. Astronomy provides firm scientific grounds for this joint training; the mathematics needed is simple, the data can be acquired with simple instrumentation in any place on the planet and the physics is rich with a broad range of levels. In addition, astronomy and space exploration are extremely appealing to young (14-17 years old) students helping to motivate them to study science doing science, i.e. to introduce Inquiry Based Scientific Education (IBSE). Since 1997 a global consortium is being developed to introduce IBSE techniques in secondary/high school education on a global scale: the Global Hands-On Universe association (www.globalhou.org) making use of the astronomical universe as a training lab. This contribution is a brief update on the current activities of the HOU consortium. Relevant URLS: www.globalhou.org, www.euhou.net, www.houspain.com.

To See the Unseen: A History of Planetary Radar Astronomy

Science.gov (United States)

Butrica, Andrew J.

1996-01-01

This book relates the history of planetary radar astronomy from its origins in radar to the present day and secondarily to bring to light that history as a case of 'Big Equipment but not Big Science'. Chapter One sketches the emergence of radar astronomy as an ongoing scientific activity at Jodrell Bank, where radar research revealed that meteors were part of the solar system. The chief Big Science driving early radar astronomy experiments was ionospheric research. Chapter Two links the Cold War and the Space Race to the first radar experiments attempted on planetary targets, while recounting the initial achievements of planetary radar, namely, the refinement of the astronomical unit and the rotational rate and direction of Venus. Chapter Three discusses early attempts to organize radar astronomy and the efforts at MIT's Lincoln Laboratory, in conjunction with Harvard radio astronomers, to acquire antenna time unfettered by military priorities. Here, the chief Big Science influencing the development of planetary radar astronomy was radio astronomy. Chapter Four spotlights the evolution of planetary radar astronomy at the Jet Propulsion Laboratory, a NASA facility, at Cornell University's Arecibo Observatory, and at Jodrell Bank. A congeries of funding from the military, the National Science Foundation, and finally NASA marked that evolution, which culminated in planetary radar astronomy finding a single Big Science patron, NASA. Chapter Five analyzes planetary radar astronomy as a science using the theoretical framework provided by philosopher of science Thomas Kuhn. Chapter Six explores the shift in planetary radar astronomy beginning in the 1970s that resulted from its financial and institutional relationship with NASA Big Science. Chapter Seven addresses the Magellan mission and its relation to the evolution of planetary radar astronomy from a ground-based to a space-based activity. Chapters Eight and Nine discuss the research carried out at ground-based

School-Based Extracurricular Astronomy

Science.gov (United States)

Stanger, Jeffrey J.

2010-01-01

The International Year of Astronomy in 2009 focused considerable public attention on Astronomy and generated valuable resources for educators. These activities are an effective vehicle for promoting Science to students and to the wider school community. The most engaging practical astronomy activities are best delivered with sustained support from…

The Monitoring Case of Ground-Based Synthetic Aperture Radar with Frequency Modulated Continuous Wave System

Science.gov (United States)

Zhang, H. Y.; Zhai, Q. P.; Chen, L.; Liu, Y. J.; Zhou, K. Q.; Wang, Y. S.; Dou, Y. D.

2017-09-01

The features of the landslide geological disaster are wide distribution, variety, high frequency, high intensity, destructive and so on. It has become a natural disaster with harmful and wide range of influence. The technology of ground-based synthetic aperture radar is a novel deformation monitoring technology developed in recent years. The features of the technology are large monitoring area, high accuracy, long distance without contact and so on. In this paper, fast ground-based synthetic aperture radar (Fast-GBSAR) based on frequency modulated continuous wave (FMCW) system is used to collect the data of Ma Liuzui landslide in Chongqing. The device can reduce the atmospheric errors caused by rapidly changing environment. The landslide deformation can be monitored in severe weather conditions (for example, fog) by Fast-GBSAR with acquisition speed up to 5 seconds per time. The data of Ma Liuzui landslide in Chongqing are analyzed in this paper. The result verifies that the device can monitor landslide deformation under severe weather conditions.

A Bayesian approach to multi-messenger astronomy: identification of gravitational-wave host galaxies

International Nuclear Information System (INIS)

Fan, XiLong; Messenger, Christopher; Heng, Ik Siong

2014-01-01

We present a general framework for incorporating astrophysical information into Bayesian parameter estimation techniques used by gravitational wave data analysis to facilitate multi-messenger astronomy. Since the progenitors of transient gravitational wave events, such as compact binary coalescences, are likely to be associated with a host galaxy, improvements to the source sky location estimates through the use of host galaxy information are explored. To demonstrate how host galaxy properties can be included, we simulate a population of compact binary coalescences and show that for ∼8.5% of simulations within 200 Mpc, the top 10 most likely galaxies account for a ∼50% of the total probability of hosting a gravitational wave source. The true gravitational wave source host galaxy is in the top 10 galaxy candidates ∼10% of the time. Furthermore, we show that by including host galaxy information, a better estimate of the inclination angle of a compact binary gravitational wave source can be obtained. We also demonstrate the flexibility of our method by incorporating the use of either the B or K band into our analysis.

Analysis of seismic waves and strong ground motion

International Nuclear Information System (INIS)

Simpson, I.C.; Sutton, R.

1976-10-01

A number of Western USA earthquake acceleration-time histories concerning events of magnitude less than 6 are considered and their Fourier spectra calculated. An analysis of some of the simpler types of seismic wave is given in order to consider the generation of a spatially dependent acceleration-time history suitable for input into a soil-structure program of analysis. Such an acceleration-time history is required by a comprehensive analysis of soil-structure interaction since the conventionally assumed model of vertically propagating seismic waves, which give rise to three spatially independent ground motions, can lead to over-conservative estimates of the building response in the high frequency range. The possible application is discussed of a given component of a recorded acceleration-time history to the base of structure under the assumption of surface Rayleigh waves or obliquely incident P and SV bulk waves. (author)

High energy cosmic ray astronomy

International Nuclear Information System (INIS)

Fonseca, V.

1996-01-01

A brief introduction to High Energy Cosmic Ray Astronomy is presented. This field covers a 17 decade energy range (2.10 4 -10 20 ) eV. Recent discoveries done with gamma-ray detectors on-board satellites and ground-based Cherenkov devices are pushing for a fast development of new and innovative techniques, specially in the low energy region which includes the overlapping of satellite and ground-based measurements in the yet unexplored energy range 20 keV-250 GeV. Detection of unexpected extremely high energy events have triggered the interest of the international scientific community. (orig.)

Measurement of Plane-Wave Spectra of Ground Penetrating Radar Antennas

DEFF Research Database (Denmark)

Lenler-Eriksen, Hans-Rudolph; Meincke, Peter

2005-01-01

The plane-wave transmitting spectrum of a ground penetrating radar (GPR) loop antenna close to the air-soil interface is measured by means of a probe buried in soil. Probe correction is implemented based upon knowledge about the complex permittivity of the soil and the current distribution...

Testing General Relativity with Low-Frequency, Space-Based Gravitational-Wave Detectors.

Science.gov (United States)

Gair, Jonathan R; Vallisneri, Michele; Larson, Shane L; Baker, John G

2013-01-01

We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ∼ 10 -5 - 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of propagation of gravitational waves; the binding energy and gravitational-wave radiation of binaries, and therefore the time evolution of binary inspirals; the strength and shape of the waves emitted from binary mergers and ringdowns; the true nature of astrophysical black holes; and much more. The strength of this science alone calls for the swift implementation of a space-based detector; the remarkable richness of astrophysics, astronomy, and cosmology in the low-frequency gravitational-wave band make the case even stronger.

Low velocity target detection based on time-frequency image for high frequency ground wave radar

Institute of Scientific and Technical Information of China (English)

YAN Songhua; WU Shicai; WEN Biyang

2007-01-01

The Doppler spectral broadening resulted from non-stationary movement of target and radio-frequency interference will decrease the veracity of target detection by high frequency ground wave(HEGW)radar.By displaying the change of signal energy on two dimensional time-frequency images based on time-frequency analysis,a new mathematical morphology method to distinguish target from nonlinear time-frequency curves is presented.The analyzed results from the measured data verify that with this new method the target can be detected correctly from wide Doppler spectrum.

Observations of magnetohydrodynamic waves on the ground and on a satellite

International Nuclear Information System (INIS)

Lanzerotti, L.J.; Fukunishi, H.; Maclennan, C.G.; Cahill, L.J. Jr.

1976-01-01

A comparison is made of magnetohydrodynamic waves observed near the equator on Explorer 45 and at an array of ground stations in the northern hemisphere and at their conjugate station at Siple, Antartica. The data comparisons strongly support the notion that the observed waves can be considered odd mode standing waves in the magnetosphere. This conclusion has important implications for the interpretation of single-point satellite and/or ground measurements of ULF plasma wave phenomena in the magnetosphere. Further, the data comparisons strongly suggest that the overall ULF (approx.5-30 mHz) power levels are quite similar in the magnetosphere and on the ground, at least during the intervals studied

Innovative technology for optical and infrared astronomy

Science.gov (United States)

Cunningham, Colin R.; Evans, Christopher J.; Molster, Frank; Kendrew, Sarah; Kenworthy, Matthew A.; Snik, Frans

2012-09-01

Advances in astronomy are often enabled by adoption of new technology. In some instances this is where the technology has been invented specifically for astronomy, but more usually it is adopted from another scientific or industrial area of application. The adoption of new technology typically occurs via one of two processes. The more usual is incremental progress by a series of small improvements, but occasionally this process is disruptive, where a new technology completely replaces an older one. One of the activities of the OPTICON Key Technology Network over the past few years has been a technology forecasting exercise. Here we report on a recent event which focused on the more radical, potentially disruptive technologies for ground-based, optical and infrared astronomy.

Testing General Relativity with Low-Frequency, Space-Based Gravitational-Wave Detectors

Directory of Open Access Journals (Sweden)

John G. Baker

2013-09-01

Full Text Available We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ∼ 10^{-5} – 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of propagation of gravitational waves; the binding energy and gravitational-wave radiation of binaries, and therefore the time evolution of binary inspirals; the strength and shape of the waves emitted from binary mergers and ringdowns; the true nature of astrophysical black holes; and much more. The strength of this science alone calls for the swift implementation of a space-based detector; the remarkable richness of astrophysics, astronomy, and cosmology in the low-frequency gravitational-wave band make the case even stronger.

Galactic radio astronomy

CERN Document Server

Sofue, Yoshiaki

2017-01-01

This book is a concise primer on galactic radio astronomy for undergraduate and graduate students, and provides wide coverage of galactic astronomy and astrophysics such as the physics of interstellar matter and the dynamics and structure of the Milky Way Galaxy and galaxies. Radio astronomy and its technological development have led to significant progress in galactic astronomy and contributed to understanding interstellar matter and galactic structures. The book begins with the fundamental physics of radio-wave radiation, i.e., black body radiation, thermal emission, synchrotron radiation, and HI and molecular line emissions. The author then gives overviews of ingredients of galactic physics, including interstellar matter such as the neutral (HI), molecular hydrogen, and ionized gases, as well as magnetic fields in galaxies. In addition, more advanced topics relevant to the Galaxy and galaxies are also contained here: star formation, supernova remnants, the Galactic Center and black holes, galactic dynamics...

Numerical Relativity for Space-Based Gravitational Wave Astronomy

Science.gov (United States)

Baker, John G.

2011-01-01

In the next decade, gravitational wave instruments in space may provide high-precision measurements of gravitational-wave signals from strong sources, such as black holes. Currently variations on the original Laser Interferometer Space Antenna mission concepts are under study in the hope of reducing costs. Even the observations of a reduced instrument may place strong demands on numerical relativity capabilities. Possible advances in the coming years may fuel a new generation of codes ready to confront these challenges.

Electromagnetic wave scattering by aerial and ground radar objects

CERN Document Server

Sukharevsky, Oleg I

2014-01-01

Electromagnetic Wave Scattering by Aerial and Ground Radar Objects presents the theory, original calculation methods, and computational results of the scattering characteristics of different aerial and ground radar objects. This must-have book provides essential background for computing electromagnetic wave scattering in the presence of different kinds of irregularities, as well as Summarizes fundamental electromagnetic statements such as the Lorentz reciprocity theorem and the image principleContains integral field representations enabling the study of scattering from various layered structur

Europe Unveils 20-Year Plan for Brilliant Future in Astronomy

Science.gov (United States)

2008-11-01

for Earth Sciences and Astronomy (INSU) of the CNRS. To build consensus on priorities in a very diverse community, the Science Vision and Roadmap were developed in an open process involving intensive interaction with the community through large open meetings and feedback via e-mail and the web. The result is a plan now backed by astronomers in 28 Member and Associated States of the EU, with over 500 million inhabitants. Over 60 selected experts from across Europe contributed to the construction of the ASTRONET Roadmap, ensuring that European astronomy has the tools to compete successfully in answering the challenges of the Science Vision. They identified and prioritised a set of new facilities to observe the Universe from radio waves to gamma rays, to open up new ways of probing the cosmos, such as gravitational waves, and to advance in the exploration of our Solar System. In the process, they considered all the elements needed by a successful scientific enterprise, from global-scale cooperation on the largest mega-project to the need for training and recruiting skilled young scientists and engineers. One of two top-priority large ground-based projects is ESO's European Extremely Large Telescope. Its 42-metre diameter mirror will make the E-ELT the largest optical/near-infrared telescope in the world -- "the biggest eye on the sky". The science to be done with the E-ELT is extremely exciting and includes studies of exoplanets and discs, galaxy formation and dark energy. ESO Director General Tim de Zeeuw says: "The top ranking of the E-ELT in the Roadmap is a strong endorsement from the European astronomical community. This flagship project will indisputably raise the European scientific, technological and industrial profile". Among other recommendations, the Roadmap considers how to maximise the future scientific impact of existing facilities in a cost-effective manner. It also identifies a need for better access to state-of-the art computing and laboratory facilities

Effect of eccentricity on searches for gravitational waves from coalescing compact binaries in ground-based detectors

International Nuclear Information System (INIS)

Brown, Duncan A.; Zimmerman, Peter J.

2010-01-01

Inspiralling compact binaries are expected to circularize before their gravitational-wave signals reach the sensitive frequency band of ground-based detectors. Current searches for gravitational waves from compact binaries using the LIGO and Virgo detectors therefore use circular templates to construct matched filters. Binary formation models have been proposed which suggest that some systems detectable by the LIGO-Virgo network may have non-negligible eccentricity. We investigate the ability of the restricted 3.5 post-Newtonian order TaylorF2 template bank, used by LIGO and Virgo to search for gravitational waves from compact binaries with masses M≤35M · , to detect binaries with nonzero eccentricity. We model the gravitational waves from eccentric binaries using the x-model post-Newtonian formalism proposed by Hinder et al.[I. Hinder, F. Hermann, P. Laguna, and D. Shoemaker, arXiv:0806.1037v1]. We find that small residual eccentricities (e 0 · · . For eccentricities e 0 > or approx. 0.1, the loss in matched filter signal-to-noise ratio due to eccentricity can be significant and so templates which include eccentric effects will be required to perform optimal searches for such systems.

Evaluation of ground stiffness parameters using continuous surface wave geophysics

DEFF Research Database (Denmark)

Gordon, Anne; Foged, Niels

2000-01-01

Present day knowledge of the magnitude of the strain levels in the ground associated with geotechnical structures, together with an increasing number of projects requiring the best estimates of ground movements around excavations, has led to, inter alia, increased interest in measuring the very......-small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

The physics-astronomy frontier

International Nuclear Information System (INIS)

Hoyle, F.; Narlikar, K.

1980-01-01

Spacetime diagrams and the structure of matter are considered, and aspects of electrical interaction are investigated. Attention is given to radiation, quantum mechanics, spectrum lines, black bodies, stellar spectra, the H-R diagram, radio astronomy, millimeter-wave astronomy, interstellar grains and infrared astronomy, and X-ray astronomy. The strong and weak interactions are examined, taking into account atoms, nuclei, the evolution of stars, and the measurement of astronomical distances. A description of gravitational interaction is also presented. The laws of motion and gravitation are considered along with black holes, the significance of cosmology, Hubble's law, the expanding universe, the symmetries of the universe, Olbers' paradox, the big-bang universe, Mach's principle, the meaning of the expansion of the system of galaxies, the redshift-magnitude relation of Hubble and Humason, the early universe, and the geometry of special relativity

Surface Waves Propagating on Grounded Anisotropic Dielectric Slab

Directory of Open Access Journals (Sweden)

Zhuozhu Chen

2018-01-01

Full Text Available This paper investigates the characteristics of surface waves propagating on a grounded anisotropic dielectric slab. Distinct from the existing analyses that generally assume that the fields of surface wave uniformly distribute along the transverse direction of the infinitely large grounded slab, our method takes into account the field variations along the transverse direction of a finite-width slab. By solving Maxwell’s equations in closed-form, it is revealed that no pure transverse magnetic (TM or transverse electric (TE mode exists if the fields are non-uniformly distributed along the transverse direction of the grounded slab. Instead, two hybrid modes, namely quasi-TM and quasi-TE modes, are supported. In addition, the propagation characteristics of two hybrid modes supported by the grounded anisotropic slab are analyzed in terms of the slab thickness, slab width, as well as the relative permittivity tensor of the anisotropic slab. Furthermore, different methods are employed to compare the analyses, as well as to validate our derivations. The proposed method is very suitable for practical engineering applications.

Concluding Remarks: The Current Status and Future Prospects for GRB Astronomy

Science.gov (United States)

Gehrels, Neil

2009-01-01

We are in a remarkable period of discovery in GRB astronomy. The current satellites including Swift, Fermi. AGILE and INTEGRAL are detecting and observing bursts of all varieties. Increasing capabilities for follow-up observations on the ground and in space are leading to rapid and deep coverage across the electromagnetic spectrum, The future will see continued operation of the current experiments and with future missions like SVOM plus possible rni_Ssions like JANUS and EXIST. An exciting expansion of capabilities is occurring in areas of gravitational waves and neutrinos that could open new windows on the GRB phenomenon. Increased IR capabilities on the ground and with missions like JWST will enable further exploration of high redshift bursts. The future is bright.

A study of electron density profiles in relation to ionization sources and ground-based radio wave absorption measurements, part 1

Science.gov (United States)

Gnanalingam, S.; Kane, J. A.

1973-01-01

An extensive set of ground-based measurements of the diurnal variation of medium frequency radio wave adsorption and virtual height is analyzed in terms of current understanding of the D- and lower E-region ion production and loss process. When this is done a gross discrepancy arises, the source of which is not known.

Overview of diffraction gratings technologies for spaceflight satellites and ground-based telescopes

Science.gov (United States)

Cotel, A.; Liard, A.; Desserouer, F.; Pichon, P.

2017-11-01

The diffraction gratings are widely used in Space-flight satellites for spectrograph instruments or in ground-based telescopes in astronomy. The diffraction gratings are one of the key optical components of such systems and have to exhibit very high optical performances. HORIBA Jobin Yvon S.A.S. (part of HORIBA Group) is in the forefront of such gratings development for more than 40 years. During the past decades, HORIBA Jobin Yvon (HJY) has developed a unique expertise in diffraction grating design and manufacturing processes for holographic, ruled or etched gratings. We will present in this paper an overview of diffraction grating technologies especially designed for space and astronomy applications. We will firstly review the heritage of the company in this field with the space qualification of different grating types. Then, we will describe several key grating technologies developed for specific space or astronomy projects: ruled blazed low groove density plane reflection grating, high-groove density holographic toroidal and spherical grating, and finally transmission Fused Silica Etched (FSE) grism-assembled grating. We will not present the Volume Phase Holographic (VPHG) grating type which is used in Astronomy.

Ab initio calculation atomics ground state wave function for interactions Ion- Atom

International Nuclear Information System (INIS)

Shojaee, F.; Bolori zadeh, M. A.

2007-01-01

Ab initio calculation atomics ground state wave function for interactions Ion- Atom Atomic wave function expressed in a Slater - type basis obtained within Roothaan- Hartree - Fock for the ground state of the atoms He through B. The total energy is given for each atom.

Near-Field Ground Motion Modal versus Wave Propagation Analysis

Directory of Open Access Journals (Sweden)

Artur Cichowicz

2010-01-01

Full Text Available The response spectrum generally provides a good estimate of the global displacement and acceleration demand of far-field ground motion on a structure. However, it does not provide accurate information on the local shape or internal deformation of the response of the structure. Near-field pulse-like ground motion will propagate through the structure as waves, causing large, localized deformation. Therefore, the response spectrum alone is not a sufficient representation of near-field ground motion features. Results show that the drift-response technique based on a continuous shear-beam model has to be employed here to estimate structure-demand parameters when structure is exposed to the pulse like ground motion. Conduced modeling shows limited applicability of the drift spectrum based on the SDOF approximation. The SDOF drift spectrum approximation can only be applied to structures with smaller natural periods than the dominant period of the ground motion. For periods larger than the dominant period of ground motion the SDOF drift spectra model significantly underestimates maximum deformation. Strong pulse-type motions are observed in the near-source region of large earthquakes; however, there is a lack of waveforms collected from small earthquakes at very close distances that were recorded underground in mines. The results presented in this paper are relevant for structures with a height of a few meters, placed in an underground excavation. The strong ground motion sensors recorded mine-induced earthquakes in a deep gold mine, South Africa. The strongest monitored horizontal ground motion was caused by an event of magnitude 2 at a distance of 90 m with PGA 123 m/s2, causing drifts of 0.25%–0.35%. The weak underground motion has spectral characteristics similar to the strong ground motion observed on the earth's surface; the drift spectrum has a maximum value less than 0.02%.

Overview of lunar-based astronomy.

Science.gov (United States)

Smith, H. J.

The Moon offers both significant advantages and drawbacks for astronomy. Recognition of these characteristics can clarify the objectives toward which developments should be directed and can help to inhibit premature or excessive selling of lunar developments on the basis of astronomy.

Tools of radio astronomy

CERN Document Server

Wilson, Thomas L; Hüttemeister, Susanne

2013-01-01

This 6th edition of “Tools of Radio Astronomy”, the most used introductory text in radio astronomy, has been revised to reflect the current state of this important branch of astronomy. This includes the use of satellites, low radio frequencies, the millimeter/sub-mm universe, the Cosmic Microwave Background and the increased importance of mm/sub-mm dust emission. Several derivations and presentations of technical aspects of radio astronomy and receivers, such as receiver noise, the Hertz dipole and  beam forming have been updated, expanded, re-worked or complemented by alternative derivations. These reflect advances in technology. The wider bandwidths of the Jansky-VLA and long wave arrays such as LOFAR and mm/sub-mm arrays such as ALMA required an expansion of the discussion of interferometers and aperture synthesis. Developments in data reduction algorithms have been included. As a result of the large amount of data collected in the past 20 years, the discussion of solar system radio astronomy, dust em...

Measuring test mass acceleration noise in space-based gravitational wave astronomy

Science.gov (United States)

Congedo, Giuseppe

2015-03-01

The basic constituent of interferometric gravitational wave detectors—the test-mass-to-test-mass interferometric link—behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as nongravitational spurious forces. This last contribution is going to be characterized by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

Numerical implementation of Voigt and Maxwell models for simulation of waves in the ground

Directory of Open Access Journals (Sweden)

Sheshenin Sergey Vladimirovich

2014-12-01

Full Text Available A lot of papers have been dedicated to simulation of dynamic processes in soil and underground structures. For example, some authors considered wave distribution in underground water pipes for creation of vibration monitoring system, others considered theoretical and algorithm aspects of efficient implementation of realistic seismic wave attenuation due to viscosity development with the help of Finite Difference Method, etc. The paper describes the numerical simulation, designed for simulation of the stress-strain state in the ground subjected to wave processes. We consider the ground with a concrete structure immersed in. The purpose of the work is the description of small vibrations in hard soil, which can nevertheless make undesirable impact on the objects in the ground or on the surface. Explicit Wilkins type scheme is used for time integration. It has proven to be successful, including the use in a well-known LS-DYNA code. As a result we created our own computer code based on the finite element method (FEM. An example of its practical usage is given.

ULF wave effects on high frequency signal propagation through the ionosphere

Directory of Open Access Journals (Sweden)

C. L. Waters

2009-07-01

Full Text Available Variations in the total electron content (TEC of the ionosphere alter the propagation characteristics of EM radiation for frequencies above a few megahertz (MHz. Spatial and temporal variations of the ionosphere TEC influence highly sensitive, ground based spatial measurements such as those used in radio astronomy and Global Positioning System (GPS applications. In this paper we estimate the magnitudes of the changes in TEC and the time delays of high frequency signals introduced by variations in the ionosphere electron density caused by the natural spectrum of ultra-low frequency (ULF wave activity that originates in near-Earth space. The time delays and associated phase shifts depend on the frequency, spatial structure and amplitude of the ULF waves.

The Virgo gravitational wave interferometer: status and perspectives

CERN Multimedia

CERN. Geneva

2018-01-01

The first recording of a signal from a binary neutron star system by the Advanced LIGO and Advanced Virgo interferometers, and the observation of its remnants by telescopes in all bands of the electromagnetic spectrum, marked the beginning of multimessenger astronomy with gravitational waves. This followed the detection of gravitational wave signals by the LIGO interferometers in 2015, which started the detailed study of highly curved space time. These achievements come after decades of work spent understanding how to measure the tiny space time strain (h ~ 10-21) carried by gravitational waves. In the future, detectors will able to extract much more precise information from these events, or record signals from fainter sources, providing a new view of the Universe. After a presentation of the Virgo interferometer, the main results obtained from binary black hole and neutron star detection are reviewed. The focus will then shift on the perspective offered by a further reduction of noise in ground based interf...

Lunar based gamma ray astronomy

International Nuclear Information System (INIS)

Haymes, R.C.

1985-01-01

Gamma ray astronomy represents the study of the universe on the basis of the electromagnetic radiation with the highest energy. Gamma ray astronomy provides a crucial tool for the understanding of astronomical phenomena, taking into account nucleosynthesis in supernovae, black holes, active galaxies, quasars, the sources of cosmic rays, neutron stars, and matter-antimatter annihilation. Difficulties concerning the conduction of studies by gamma ray astronomy are related to the necessity to perform such studies far from earth because the atmosphere is a source of gamma rays. Studies involving the use of gamma ray instruments in earth orbit have been conducted, and more gamma ray astronomy observations are planned for the future. Imperfections of studies conducted in low earth orbit could be overcome by estalishing an observatory on the moon which represents a satellite orbiting at 60 earth radii. Details concerning such an observatory are discussed. 5 references

TeV gamma-ray astronomy

International Nuclear Information System (INIS)

Cui Wei

2009-01-01

The field of ground-based gamma-ray astronomy has enjoyed rapid growth in recent years. As an increasing number of sources are detected at TeV energies, the field has matured and become a viable branch of modern astronomy. Lying at the uppermost end of the electromagnetic rainbow, TeV photons are always preciously few in number but carry essential information about the particle acceleration and radiative processes involved in extreme astronomical settings. Together with observations at longer wavelengths, TeV gamma-ray observations have drastically improved our view of the universe. In this review, we briefly describe recent progress in the field. We will conclude by providing a personal perspective on the future of the field, in particular, on the significant roles that China could play in advancing this young but exciting field. (invited reviews)

Three-Stage InP Submillimeter-Wave MMIC Amplifier

Science.gov (United States)

Pukala, David; Samoska, Lorene; Man, King; Gaier, Todd; Deal, William; Lai, Richard; Mei, Gerry; Makishi, Stella

2008-01-01

A submillimeter-wave monolithic integrated- circuit (S-MMIC) amplifier has been designed and fabricated using an indium phosphide (InP) 35-nm gate-length high electron mobility transistor (HEMT) device, developed at Northrop Grumman Corporation. The HEMT device employs two fingers each 15 micrometers wide. The HEMT wafers are grown by molecular beam epitaxy (MBE) and make use of a pseudomorphic In0.75Ga0.25As channel, a silicon delta-doping layer as the electron supply, an In0.52Al0.48As buffer layer, and an InP substrate. The three-stage design uses coplanar waveguide topology with a very narrow ground-to-ground spacing of 14 micrometers. Quarter-wave matching transmission lines, on-chip metal-insulator-metal shunt capacitors, series thin-film resistors, and matching stubs were used in the design. Series resistors in the shunt branch arm provide the basic circuit stabilization. The S-MMIC amplifier was measured for S-parameters and found to be centered at 320 GHz with 13-15-dB gain from 300-345 GHz. This chip was developed as part of the DARPA Submillimeter Wave Imaging Focal Plane Technology (SWIFT) program (see figure). Submillimeter-wave amplifiers could enable more sensitive receivers for earth science, planetary remote sensing, and astrophysics telescopes, particularly in radio astronomy, both from the ground and in space. A small atmospheric window at 340 GHz exists and could enable ground-based observations. However, the submillimeter-wave regime (above 300 GHz) is best used for space telescopes as Earth s atmosphere attenuates most of the signal through water and oxygen absorption. Future radio telescopes could make use of S-MMIC amplifiers for wideband, low noise, instantaneous frequency coverage, particularly in the case of heterodyne array receivers.

Exploring the Birth and Evolution of the Universe: How Detectors Have Revolutionized Space Astronomy

Science.gov (United States)

Moseley, Samuel H.

2012-01-01

The past century has seen tremendous advances in the capability of instruments used for astronomical imaging and spectroscopy. Capabilities of instruments have expanded in many dimensions; the scale of telescopes has grown tremendously, the wavelengths used for astronomy have grown from visible light to the full electromagnetic spectrum, extending from gamma rays to low frequency radio waves. Additional advances have been enabled by the availability of space facilities, which eliminate the effects of the earths atmosphere and magnetosphere, and allow cooling of instruments to avoid instrumental thermal radiation. Even with all these advances, the increase in capability of detection systems has produced truly revolutionary improvements in capability. Today, I will describe the advances in astronomical detection from the photographic plates of the early 20th century to the giant high efficiency focal planes being developed for modern space and ground based astronomical instrument. I will review the demanding performance requirements set by space astronomy, and show how the detector community has risen to the challenge in producing high performance detectors for the Hubble Space Telescope, the Spitzer Space Telescope, and the James Webb Space Telescope, now under development.

Gamma ray astronomy

International Nuclear Information System (INIS)

Fichtel, C.E.

1975-01-01

The first certain detection of celestial high energy gamma rays came from a satellite experiment flown on the third Orbiting Solar Observatory (OSO-111). A Gamma ray spark chamber telescope with substantively greater sensitivity and angular resolution (a few degrees) flown on the second Small Astronomy Satellite (SAS-II) has now provided a better picture of the gamma ray sky, and particularly the galactic plane and pulsars. This paper will summarize the present picture of gamma ray astronomy as it has developed at this conference from measurements made with experiments carried out on balloons, those remaining on the ground, and ones flown on satellites. (orig.) [de

S-Cam 3: Optical astronomy with a STJ-based imaging spectrophotometer

International Nuclear Information System (INIS)

Verhoeve, P.; Martin, D.D.E.; Hijmering, R.A.; Verveer, J.; Dordrecht, A. van; Sirbi, G.; Oosterbroek, T.; Peacock, A.

2006-01-01

S-Cam 3 is the third generation of a cryogenic camera, based on superconducting tunnel junctions (STJs), for ground-based optical astronomy, deployed at the 4.2 m William Herschel Telescope (WHT) at La Palma (Spain). It exploits a 10x12 pixel array of Ta/Al STJs, covering a field of view of ∼9''x11'' on the sky. The wavelength band extends from 330-750 nm, with a wavelength resolving power of ∼10 at 500 nm. The detectors are operated at ∼285 mK, achieved with a double stage 4 He- 3 He sorption cooler. Each pixel has its own electronic readout chain at room temperature, with a JFET-based charge sensitive preamplifier. The instrument has undergone extensive testing and calibration, followed by the first observation campaign at La Palma in July 2004. This campaign has focused on point sources with time variability, exploiting the instrument's unique combination of spectrophotometry with high time resolution

OBSERVATIONAL SELECTION EFFECTS WITH GROUND-BASED GRAVITATIONAL WAVE DETECTORS

International Nuclear Information System (INIS)

Chen, Hsin-Yu; Holz, Daniel E.; Essick, Reed; Vitale, Salvatore; Katsavounidis, Erik

2017-01-01

Ground-based interferometers are not perfect all-sky instruments, and it is important to account for their behavior when considering the distribution of detected events. In particular, the LIGO detectors are most sensitive to sources above North America and the Indian Ocean, and as the Earth rotates, the sensitive regions are swept across the sky. However, because the detectors do not acquire data uniformly over time, there is a net bias on detectable sources’ right ascensions. Both LIGO detectors preferentially collect data during their local night; it is more than twice as likely to be local midnight than noon when both detectors are operating. We discuss these selection effects and how they impact LIGO’s observations and electromagnetic (EM) follow-up. Beyond galactic foregrounds associated with seasonal variations, we find that equatorial observatories can access over 80% of the localization probability, while mid-latitudes will access closer to 70%. Facilities located near the two LIGO sites can observe sources closer to their zenith than their analogs in the south, but the average observation will still be no closer than 44° from zenith. We also find that observatories in Africa or the South Atlantic will wait systematically longer before they can begin observing compared to the rest of the world; though, there is a preference for longitudes near the LIGOs. These effects, along with knowledge of the LIGO antenna pattern, can inform EM follow-up activities and optimization, including the possibility of directing observations even before gravitational-wave events occur.

OBSERVATIONAL SELECTION EFFECTS WITH GROUND-BASED GRAVITATIONAL WAVE DETECTORS

Energy Technology Data Exchange (ETDEWEB)

Chen, Hsin-Yu; Holz, Daniel E. [University of Chicago, Chicago, Illinois 60637 (United States); Essick, Reed; Vitale, Salvatore; Katsavounidis, Erik [LIGO, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2017-01-20

Ground-based interferometers are not perfect all-sky instruments, and it is important to account for their behavior when considering the distribution of detected events. In particular, the LIGO detectors are most sensitive to sources above North America and the Indian Ocean, and as the Earth rotates, the sensitive regions are swept across the sky. However, because the detectors do not acquire data uniformly over time, there is a net bias on detectable sources’ right ascensions. Both LIGO detectors preferentially collect data during their local night; it is more than twice as likely to be local midnight than noon when both detectors are operating. We discuss these selection effects and how they impact LIGO’s observations and electromagnetic (EM) follow-up. Beyond galactic foregrounds associated with seasonal variations, we find that equatorial observatories can access over 80% of the localization probability, while mid-latitudes will access closer to 70%. Facilities located near the two LIGO sites can observe sources closer to their zenith than their analogs in the south, but the average observation will still be no closer than 44° from zenith. We also find that observatories in Africa or the South Atlantic will wait systematically longer before they can begin observing compared to the rest of the world; though, there is a preference for longitudes near the LIGOs. These effects, along with knowledge of the LIGO antenna pattern, can inform EM follow-up activities and optimization, including the possibility of directing observations even before gravitational-wave events occur.

Under the Radar: The First Woman in Radio Astronomy, Ruby Payne-Scott

Science.gov (United States)

Miller Goss, W.

2012-05-01

Under the Radar, the First Woman in Radio Astronomy, Ruby Payne-Scott W. Miller Goss, NRAO Socorro NM Ruby Payne-Scott (1912-1981) was an eminent Australian scientist who made major contributions to the WWII radar effort (CSIR) from 1941 to 1945. In late 1945, she pioneered radio astronomy efforts at Dover Heights in Sydney, Australia at a beautiful cliff top overlooking the Tasman Sea. Again at Dover Heights, Payne-Scott carried out the first interferometry in radio astronomy using an Australian Army radar antenna as a radio telescope at sun-rise, 26 January 1946. She continued these ground breaking activities until 1951. Ruby Payne-Scott played a major role in discovering and elucidating the properties of Type III bursts from the sun, the most common of the five classes of transient phenomena from the solar corona. These bursts are one of the most intensively studied forms of radio emission in all of astronomy. She is also one of the inventors of aperture synthesis in radio astronomy. I examine her career at the University of Sydney and her conflicts with the CSIR hierarchy concerning the rights of women in the work place, specifically equal wages and the lack of permanent status for married women. I also explore her membership in the Communist Party of Australia as well as her partially released Australian Scientific Intelligence Organization file. Payne-Scott’s role as a major participant in the flourishing radio astronomy research of the post war era remains a remarkable story. She had a number of strong collaborations with the pioneers of early radio astronomy in Australia: Pawsey, Mills, Christiansen, Bolton and Little. I am currently working on a popular version of the Payne-Scott story; “Making Waves, The Story of Ruby Payne-Scott: Australian Pioneer Radio Astronomer” will be published in 2013 by Springer in the Astronomers’ Universe Series.

Intelligent Cognitive Radio Models for Enhancing Future Radio Astronomy Observations

Directory of Open Access Journals (Sweden)

Ayodele Abiola Periola

2016-01-01

Full Text Available Radio astronomy organisations desire to optimise the terrestrial radio astronomy observations by mitigating against interference and enhancing angular resolution. Ground telescopes (GTs experience interference from intersatellite links (ISLs. Astronomy source radio signals received by GTs are analysed at the high performance computing (HPC infrastructure. Furthermore, observation limitation conditions prevent GTs from conducting radio astronomy observations all the time, thereby causing low HPC utilisation. This paper proposes mechanisms that protect GTs from ISL interference without permanent prevention of ISL data transmission and enhance angular resolution. The ISL transmits data by taking advantage of similarities in the sequence of observed astronomy sources to increase ISL connection duration. In addition, the paper proposes a mechanism that enhances angular resolution by using reconfigurable earth stations. Furthermore, the paper presents the opportunistic computing scheme (OCS to enhance HPC utilisation. OCS enables the underutilised HPC to be used to train learning algorithms of a cognitive base station. The performances of the three mechanisms are evaluated. Simulations show that the proposed mechanisms protect GTs from ISL interference, enhance angular resolution, and improve HPC utilisation.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy. NAGENDRA KUMAR. Articles written in Journal of Astrophysics and Astronomy. Volume 29 Issue 1-2 March-June 2008 pp 243-248. Damping of Slow Magnetoacoustic Waves in an Inhomogeneous Coronal Plasma · Nagendra Kumar Pradeep ...

Ion cyclotron waves: Direct compariosn between ground-based measurements and observations in the source region

International Nuclear Information System (INIS)

Perraut, S.; Gendrin, R.; Roux, A.; de Villedary, C.

1984-01-01

Simultaneous measurements of ion cyclotron waves (ICW's) were performed on GEOS spacecraft and in the vicinity of their magnetic footprints with the French Mobile station. The detailed comparison between the two sets of data shown that while ICW's having F + gyrofrequency at the equator, generally propagate to the ground, only 50% of those generated above F/sub He/ can reach the ground station. It is shown that these results are in good agreement with the conclusions that Rauch and Roux [1982] drew on the basis of measurements reported by Young et al 1981]. In an He + -rich plasma, ICW's with F>F/sub He/ suffer a reflection where the frequency locally matches the local bi-ion hybrid frequency. We extend the calculations of Rauch and Roux and calculate, as a function of the He + concentration, the tunneling of ICW's through the stopband induced by the presence of minor He + ions. It is shown that the transmission coefficient strongly depends upon the wave frequency for a given He + abundance ratio. The results obtained are shown to be supported by existing observations

Advances in astronomy and astrophysics

CERN Document Server

Kopal, Zdenek

1962-01-01

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

Introduction. Progress in astronomy: from gravitational waves to space weather.

Science.gov (United States)

Thompson, J Michael T

2008-12-13

This brief paper introduces and reviews the 'visions of the future' articles prepared by leading young scientists throughout the world for the first of two Christmas 2008 Triennial issues of Phil. Trans. R. Soc. A, devoted, respectively, to astronomy and Earth science. Contributions in astronomy include the very topical gamma-ray bursts, new ideas on stellar collapse and the unusual atmospheres of synchronized planets orbiting nearby stars.

Gravitational waves and antennas

CERN Multimedia

CERN. Geneva

2003-01-01

Gravitational waves and their detection represent today a hot topic, which promises to play a central role in astrophysics, cosmology and theoretical physics. Technological developments have enabled the construction of such sensitive detectors that the detection of gravitational radiation and the start of a new astronomy could become a reality during the next few years. This is expected to bring a revolution in our knowledge of the universe by allowing the observation of hiterto unseen phenomena such as coalescence of compact objects (neutron stars and black holes) fall of stars into supermassive black holes, stellar core collapses, big bang relics and the new and unexpected. In these lectures I give a brief overview of this challenging field of modern physics. Topics : Basic properties of gravitational radiation. Astrophysical sources. Principle of operation of detectors. Interferometers (both ground based and space-based), bars and spheres. Present status of the experiments, their recent results and their f...

Event-sequence time series analysis in ground-based gamma-ray astronomy

International Nuclear Information System (INIS)

Barres de Almeida, U.; Chadwick, P.; Daniel, M.; Nolan, S.; McComb, L.

2008-01-01

The recent, extreme episodes of variability detected from Blazars by the leading atmospheric Cerenkov experiments motivate the development and application of specialized statistical techniques that enable the study of this rich data set to its furthest extent. The identification of the shortest variability timescales supported by the data and the actual variability structure observed in the light curves of these sources are some of the fundamental aspects being studied, that answers can bring new developments on the understanding of the physics of these objects and on the mechanisms of production of VHE gamma-rays in the Universe. Some of our efforts in studying the time variability of VHE sources involve the application of dynamic programming algorithms to the problem of detecting change-points in a Poisson sequence. In this particular paper we concentrate on the more primary issue of the applicability of counting statistics to the analysis of time-series on VHE gamma-ray astronomy.

Infrared Astronomy Satellite

Science.gov (United States)

Ferrera, G. A.

1981-09-01

In 1982, the Infrared Astronomy Satellite (IRAS) will be launched into a 900-km sun-synchronous (twilight) orbit to perform an unbiased, all-sky survey of the far-infrared spectrum from 8 to 120 microns. Observations telemetered to ground stations will be compiled into an IR astronomy catalog. Attention is given the cryogenically cooled, 60-cm Ritchey-Chretien telescope carried by the satellite, whose primary and secondary mirrors are fabricated from beryllium by means of 'Cryo-Null Figuring'. This technique anticipates the mirror distortions that will result from cryogenic cooling of the telescope and introduces dimensional compensations for them during machining and polishing. Consideration is also given to the interferometric characterization of telescope performance and Cryo/Thermal/Vacuum simulated space environment testing.

Energy, The Environment And Astronomy: Education And Action

Science.gov (United States)

Rodgers, Bernadette; Doppmann, G.; Kalas, P.; Lacy, J.; Beck, T.; Marshall, P. J.

2010-01-01

The specter of global climate change is arguably the most pressing scientific, social and ethical issue of our time. Although the relatively small field of astronomy represents only a fraction of the total human carbon emissions, astronomers have a great potential, and therefore perhaps a great responsibility, to educate themselves and the public on this issue. In addition, the average per capita carbon emissions of professional astronomers are not small, and our profession can do much to reduce its energy consumption and maximize the cost-benefit ratio of our work. At the January AAS meeting, we are organizing a half-day splinter meeting titled "Energy, the Environment and Astronomy: Education and Action". The focus will be on energy conservation and education as it relates to professional astronomy. Education focuses on informing ourselves, our students and the general public with which we interact, about the real issues, the necessary actions, and the likely consequences of various energy consumption and carbon emission scenarios. Action focuses on effective energy conservation and renewable energy initiatives within professional astronomy. Air travel, solar energy at ground-based observatories, and Gemini's "Green Initiative” are among the topics that will be discussed. The splinter meeting will be open to all and will include expert speakers from outside astronomy, contributed talks by astronomers, and a discussion session.

EGC: a time-frequency augmented template-based method for gravitational wave burst search in ground-based interferometers

International Nuclear Information System (INIS)

Clapson, Andre-Claude; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Leroy, Nicolas; Varvella, Monica

2008-01-01

The detection of burst-type events in the output of ground gravitational wave detectors is particularly challenging. The potential variety of astrophysical waveforms, as proposed by simulations and analytic studies in general relativity and the discrimination of actual signals from instrumental noise both are critical issues. Robust methods that achieve reasonable detection performances over a wide range of signals are required. We present here a hybrid burst-detection pipeline related to time-frequency transforms while based on matched filtering to provide robustness against noise characteristics. Studies on simulated noise show that the algorithm has a detection efficiency similar to other methods over very different waveforms and particularly good timing even for low amplitude signals: no bias for most tested waveforms and an average accuracy of 1.1 ms (down to 0.1 ms in the best case). Time-frequency-type parameters, useful for event classification, are also derived for noise spectral densities unfavourable to standard time-frequency algorithms

EGC: a time-frequency augmented template-based method for gravitational wave burst search in ground-based interferometers

Energy Technology Data Exchange (ETDEWEB)

Clapson, Andre-Claude; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Leroy, Nicolas; Varvella, Monica [LAL, Universite Paris-Sud 11, BP 34, 91898 Orsay (France)

2008-02-07

The detection of burst-type events in the output of ground gravitational wave detectors is particularly challenging. The potential variety of astrophysical waveforms, as proposed by simulations and analytic studies in general relativity and the discrimination of actual signals from instrumental noise both are critical issues. Robust methods that achieve reasonable detection performances over a wide range of signals are required. We present here a hybrid burst-detection pipeline related to time-frequency transforms while based on matched filtering to provide robustness against noise characteristics. Studies on simulated noise show that the algorithm has a detection efficiency similar to other methods over very different waveforms and particularly good timing even for low amplitude signals: no bias for most tested waveforms and an average accuracy of 1.1 ms (down to 0.1 ms in the best case). Time-frequency-type parameters, useful for event classification, are also derived for noise spectral densities unfavourable to standard time-frequency algorithms.

Hartree-Fock implementation using a Laguerre-based wave function for the ground state and correlation energies of two-electron atoms.

Science.gov (United States)

King, Andrew W; Baskerville, Adam L; Cox, Hazel

2018-03-13

An implementation of the Hartree-Fock (HF) method using a Laguerre-based wave function is described and used to accurately study the ground state of two-electron atoms in the fixed nucleus approximation, and by comparison with fully correlated (FC) energies, used to determine accurate electron correlation energies. A variational parameter A is included in the wave function and is shown to rapidly increase the convergence of the energy. The one-electron integrals are solved by series solution and an analytical form is found for the two-electron integrals. This methodology is used to produce accurate wave functions, energies and expectation values for the helium isoelectronic sequence, including at low nuclear charge just prior to electron detachment. Additionally, the critical nuclear charge for binding two electrons within the HF approach is calculated and determined to be Z HF C =1.031 177 528.This article is part of the theme issue 'Modern theoretical chemistry'. © 2018 The Author(s).

Classics in radio astronomy

CERN Document Server

Sullivan, Woodruff Turner

1982-01-01

Radio techniques were the nrst to lead astronomy away from the quiescent and limited Universe revealed by traditional observations at optical wave­ lengths. In the earliest days of radio astronomy, a handful of radio physicists and engineers made one startling discovery after another as they opened up the radio sky. With this collection of classic papers and the extensive intro­ ductory material, the reader can experience these exciting discoveries, as well as understand the developing techniques and follow the motivations which prompted the various lines of inquiry. For instance he or she will follow in detail the several attempts to detect radio waves from the sun at the turn of the century; the unravelling by Jansky of a "steady hiss type static"; the incredible story of Reber who built a 9 meter dish in his backyard in 1937 and then mapped the Milky Way; the vital discoveries by Hey and colleagues of radio bursts from the Sun and of a discrete source in the constellation of Cygnus; the development of re...

GPM GROUND VALIDATION CONICAL SCANNING MILLIMETER-WAVE IMAGING RADIOMETER (COSMIR) GCPEX V1

Data.gov (United States)

National Aeronautics and Space Administration — The GPM Ground Validation Conical Scanning Millimeter-wave Imaging Radiometer (COSMIR) GCPEx dataset used the Conical Scanning Millimeter-wave Imaging Radiometer...

A Novel High-Frequency Voltage Standing-Wave Ratio-Based Grounding Electrode Line Fault Supervision in Ultra-High Voltage DC Transmission Systems

Directory of Open Access Journals (Sweden)

Yufei Teng

2017-03-01

Full Text Available In order to improve the fault monitoring performance of grounding electrode lines in ultra-high voltage DC (UHVDC transmission systems, a novel fault monitoring approach based on the high-frequency voltage standing-wave ratio (VSWR is proposed in this paper. The VSWR is defined considering a lossless transmission line, and the characteristics of the VSWR under different conditions are analyzed. It is shown that the VSWR equals 1 when the terminal resistance completely matches the characteristic impedance of the line, and when a short circuit fault occurs on the grounding electrode line, the VSWR will be greater than 1. The VSWR will approach positive infinity under metallic earth fault conditions, whereas the VSWR in non-metallic earth faults will be smaller. Based on these analytical results, a fault supervision criterion is formulated. The effectiveness of the proposed VSWR-based fault supervision technique is verified with a typical UHVDC project established in Power Systems Computer Aided Design/Electromagnetic Transients including DC(PSCAD/EMTDC. Simulation results indicate that the proposed strategy can reliably identify the grounding electrode line fault and has strong anti-fault resistance capability.

Gravitational-Wave Astronomy

Indian Academy of Sciences (India)

Keywords. General relativity; gravitational waves; astrophysics; interferometry. Author Affiliations. P Ajith1 K G Arun2. LIGO Laboratory and Theoretical Astrophysics California Institute of Technology MS 18-34, Pasadena CA 91125, USA. Chennai Mathematical Institute Plot H1, SIPCOT IT Park Siruseri, Padur Post Chennai ...

Characteristics of the magnetohydrodynamic waves observed in the earth's magnetosphere and on the ground

International Nuclear Information System (INIS)

Kuwashima, M.; Fujita, S.

1989-01-01

Current research topics on MHD waves in the earth's magnetosphere and on the ground are summarized. Upstream waves in the earth's foreshock region and their transmission into and propagation through the magnetosphere are discussed in the context of relationships of Pc3 magnetic pulsations on the ground. The characteristics of ssc-associated magnetic pulsations are considered, and instabilities with the hot plasma in the ring current in the magnetosphere are addressed in the context of the relationships of compressional Pc 4-5 waves. The characteristics of Pi2 magnetic pulsations are examined, and the role of the ionosphere on the modifications of MHD waves is addressed

ESASky: a new Astronomy Multi-Mission Interface

Science.gov (United States)

Baines, D.; Merin, B.; Salgado, J.; Giordano, F.; Sarmiento, M.; Lopez Marti, B.; Racero, E.; Gutierrez, R.; De Teodoro, P.; Nieto, S.

2016-06-01

ESA is working on a science-driven discovery portal for all its astronomy missions at ESAC called ESASky. The first public release of this service will be shown, featuring interfaces for sky exploration and for single and multiple targets. It requires no operational knowledge of any of the missions involved. A first public beta release took place in October 2015 and gives users world-wide simplified access to high-level science-ready data products from ESA Astronomy missions plus a number of ESA-produced source catalogues. XMM-Newton data, metadata and products were some of the first to be accessible through ESASky. In the next decade, ESASky aims to include not only ESA missions but also access to data from other space and ground-based astronomy missions and observatories. From a technical point of view, ESASky is a web application that offers all-sky projections of full mission datasets using a new-generation HEALPix projection called HiPS; detailed geometrical footprints to connect all-sky mosaics to individual observations; direct access to the underlying mission-specific science archives and catalogues. The poster will be accompanied by a demo booth at the conference.

Misconceptions in Astronomy: Before and After a Constructivist Learning Environment

Science.gov (United States)

Ruzhitskaya, Lanika; Speck, A.

2009-01-01

We present results of a pilot study on college students’ misconceptions in astronomy. The study was conducted on the campus of a Midwestern university among 43 non-science major students enrolled in an introductory astronomy laboratory course. The laboratory course was based on a constructivist learning environment where students learned astronomy by doing astronomy. During the course, students worked with educational simulations created by Project CLEA team and RedShift College Education Astronomy Workbook by Bill Walker as well as were involved in think-pair-share discussions based on Lecture-Tutorials (Prather et al 2008). Several laboratories were prompted by an instructor's brief presentations. On the first and last days of the course students were surveyed on what their beliefs were about causes of the seasons, the moon's apparent size in the sky and its phases, planetary orbits, structure of the solar system, the sun, distant stars, and the nature of light. The majority of the surveys’ questions were based on Neil Comins’ 50 most commonly cited misconceptions. The outcome of the study showed that while students constructed correct understanding of a number of phenomena, they also created a set of new misconceptions. For example, if on the first day of the course, nine out of 43 students knew what caused the seasons on Earth; on the last day of the course, 20 students gained the similar understanding. However, by the end of the course more students believed that smaller planets must rotate faster based on the conservation of angular momentum and Kepler's laws. Our findings suggest that misconceptions pointed out by Neil Comins over a decade ago are still relevant today; and that learning based exclusively on simulations and collaborative group discussions does not necessarily produce the best results, but may set a ground for creating new misconceptions.

Back Radiation Suppression through a Semitransparent Ground Plane for a mm-Wave Patch Antenna

KAUST Repository

Klionovski, Kirill

2017-06-21

Omnidirectional radiation pattern with minimum backward radiation is highly desirable for base station antennas to minimize the multipath effects. Semitransparent ground planes have been used to reduce the backward radiation, but mostly with complicated non-uniform impedance distribution. In this work, we propose, for the first time, a round semitransparent ground plane of radius 0.8 λ with uniform impedance distribution that can improve the front-to-back ratio of a wideband patch antenna by 11.6 dB as compared to a similar sized metallic ground plane. The value of uniform impedance is obtained through analytical optimization by using asymptotic expressions in the Kirchhoff approximation of the radiation pattern of a toroidal wave scattered by a round semitransparent ground plane. The semitransparent ground plane has been realized using a low-cost carbon paste on a Kapton film. Experimental results match closely with those of simulations and validate the overall concept.

Gravitational wave tests of general relativity with the parameterized post-Einsteinian framework

International Nuclear Information System (INIS)

Cornish, Neil; Sampson, Laura; Yunes, Nicolas; Pretorius, Frans

2011-01-01

Gravitational wave astronomy has tremendous potential for studying extreme astrophysical phenomena and exploring fundamental physics. The waves produced by binary black hole mergers will provide a pristine environment in which to study strong-field dynamical gravity. Extracting detailed information about these systems requires accurate theoretical models of the gravitational wave signals. If gravity is not described by general relativity, analyses that are based on waveforms derived from Einstein's field equations could result in parameter biases and a loss of detection efficiency. A new class of ''parameterized post-Einsteinian'' waveforms has been proposed to cover this eventuality. Here, we apply the parameterized post-Einsteinian approach to simulated data from a network of advanced ground-based interferometers and from a future space-based interferometer. Bayesian inference and model selection are used to investigate parameter biases, and to determine the level at which departures from general relativity can be detected. We find that in some cases the parameter biases from assuming the wrong theory can be severe. We also find that gravitational wave observations will beat the existing bounds on deviations from general relativity derived from the orbital decay of binary pulsars by a large margin across a wide swath of parameter space.

Morphology of low-frequency waves in the solar wind and their relation to ground pulsations

International Nuclear Information System (INIS)

Odera, T.J.; Stuart, W.F.

1986-01-01

Three classes of low frequency waves (period range 20 to 80 s) were identified using data from the UCLA fluxgate magnetometer experiment on board the ISEE 2 spacecraft. These are continuous pulsations similar in type to Pc 3, band-limited oscillations distinguished by mixed period fluctuations, and relatively isolated wave bundles. The waves were preferentially observed when the interplanetary magnetic field (IMF) direction was sunward and were most common when the cone angle, i.e. the angle between IMF and the Sun-Earth line (thetasub(xB)) was often between 15 deg and 45 deg. Their frequency is proportional to the IMF magnitude. Comparison between the waves observed on board the ISEE 2 spacecraft and the Pc 3-4 recorded simultaneously at a mid-latitude ground station, Oulu (L = 4.5), showed that similarity of spectra of the waves in the spacecraft and on the ground was very rare and that correspondence between the events in space and on the ground was extremely low. (author)

Summer planetary-scale oscillations: aura MLS temperature compared with ground-based radar wind

Directory of Open Access Journals (Sweden)

C. E. Meek

2009-04-01

Full Text Available The advent of satellite based sampling brings with it the opportunity to examine virtually any part of the globe. Aura MLS mesospheric temperature data are analysed in a wavelet format for easy identification of possible planetary waves (PW and aliases masquerading as PW. A calendar year, 2005, of eastward, stationary, and westward waves at a selected latitude is shown in separate panels for wave number range −3 to +3 for period range 8 h to 30 days (d. Such a wavelet analysis is made possible by Aura's continuous sampling at all latitudes 82° S–82° N. The data presentation is suitable for examination of years of data. However this paper focuses on the striking feature of a "dish-shaped" upper limit to periods near 2 d in mid-summer, with longer periods appearing towards spring and fall, a feature also commonly seen in radar winds. The most probable cause is suggested to be filtering by the summer jet at 70–80 km, the latter being available from ground based medium frequency radar (MFR. Classically, the phase velocity of a wave must be greater than that of the jet in order to propagate through it. As an attempt to directly relate satellite and ground based sampling, a PW event of period 8d and wave number 2, which appears to be the original rather than an alias, is compared with ground based radar wind data. An appendix discusses characteristics of satellite data aliases with regard to their periods and amplitudes.

The Mercedes-Benz approach to γ-ray astronomy

International Nuclear Information System (INIS)

Akerlof, C.W.

1988-01-01

The sensitivity requirements for ground-based γ-ray astronomy are reviewed in the light of the most reliable estimates of stellar fluxes above 100 GeV. Current data strongly favor the construction of detectors with the lowest energy thresholds. Since improvements in angular resolution are limited by shower fluctuations, better methods of rejecting hadronic showers must be found to reliably observe the known astrophysical sources. Several possible methods for reducing this hadronic background are discussed. (orig.)

TeachAstronomy.com - Digitizing Astronomy Resources

Science.gov (United States)

Hardegree-Ullman, Kevin; Impey, C. D.; Austin, C.; Patikkal, A.; Paul, M.; Ganesan, N.

2013-06-01

Teach Astronomy—a new, free online resource—can be used as a teaching tool in non-science major introductory college level astronomy courses, and as a reference guide for casual learners and hobbyists. Digital content available on Teach Astronomy includes: a comprehensive introductory astronomy textbook by Chris Impey, Wikipedia astronomy articles, images from Astronomy Picture of the Day archives and (new) AstroPix database, two to three minute topical video clips by Chris Impey, podcasts from 365 Days of Astronomy archives, and an RSS feed of astronomy news from Science Daily. Teach Astronomy features an original technology called the Wikimap to cluster, display, and navigate site search results. Development of Teach Astronomy was motivated by steep increases in textbook prices, the rapid adoption of digital resources by students and the public, and the modern capabilities of digital technology. This past spring semester Teach Astronomy was used as content supplement to lectures in a massive, open, online course (MOOC) taught by Chris Impey. Usage of Teach Astronomy has been steadily growing since its initial release in August of 2012. The site has users in all corners of the country and is being used as a primary teaching tool in at least four states.

“Big Data” Teen Astronomy Cafes at NOAO

Science.gov (United States)

Pompea, Stephen; Walker, Constance E.

2018-01-01

The National Optical Astronomy Observatory has designed and implemented a prototype educational program designed to test and understand best practices with high school students to promote an understanding of modern astronomy research with its emphasis on large data sets, data tools, and visualization tools. This program, designed to cultivate the interest of talented youth in astronomy, is based on a teen science café model developed at Los Alamos as the Café Scientifique New Mexico. In our program, we provide a free, fun way for teens to explore current research topics in astronomy on Saturday mornings at the NOAO headquarters. The program encourages stimulating conversations with astronomers in an informal and relaxed setting, with free food of course. The café is organized through a leadership team of local high school students and recruits students from all parts of the greater Tucson area. The high school students who attend have the opportunity to interact with expert astronomers working with large astronomical data sets on topics such as killer asteroids, the birth and death of stars, colliding galaxies, the structure of the universe, gravitational waves, gravitational lensing, dark energy, and dark matter. The students also have the opportunity to explore astronomical data sets and data tools using computers provided by the program. The program may serve as a model for educational outreach for the 40+ institutions involved in the LSST.

Solving ground eigenvalue and eigenfunction of spheroidal wave equation at low frequency by supersymmetric quantum mechanics method

Institute of Scientific and Technical Information of China (English)

Tang Wen-Lin; Tian Gui-Hua

2011-01-01

The spheroidal wave functions are found to have extensive applications in many branches of physics and mathematics. We use the perturbation method in supersymmetric quantum mechanics to obtain the analytic ground eigenvalue and the ground eigenfunction of the angular spheroidal wave equation at low frequency in a series form. Using this approach, the numerical determinations of the ground eigenvalue and the ground eigenfunction for small complex frequencies are also obtained.

Inspiring the Next Generation: Astronomy Catalyzes K12 STEM Education

Science.gov (United States)

Borders, Kareen; Thaller, Michelle; Winglee, Robert; Borders, Kyla

2017-06-01

K-12 educators need effective and relevant astronomy professional development. NASA's Mission Science provides innovative and accessible opportunities for K-12 teachers. Science questions involve scale and distance, including Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers can gain an understanding of basic telescopes, the history of telescopes, ground and satellite based telescopes, and models of JWST Telescope. An in-depth explanation of JWST and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. During teacher training, we taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of lenticulars and diagramming of infrared data, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars.We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development.Funding was provided by Washington STEM, NASA, and the Washington Space Grant Consortium.

Gravitational Waves

Energy Technology Data Exchange (ETDEWEB)

Miller, Jonah Maxwell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-10-18

This report has slides on Gravitational Waves; Pound and Rebka: A Shocking Fact; Light is a Ruler; Gravity is the Curvature of Spacetime; Gravitational Waves Made Simple; How a Gravitational Wave Affects Stuff Here; LIGO; This Detection: Neutron Stars; What the Gravitational Wave Looks Like; The Sound of Merging Neutron Stars; Neutron Star Mergers: More than GWs; The Radioactive Cloud; The Kilonova; and finally Summary, Multimessenger Astronomy.

Web-based visualization of very large scientific astronomy imagery

Science.gov (United States)

Bertin, E.; Pillay, R.; Marmo, C.

2015-04-01

Visualizing and navigating through large astronomy images from a remote location with current astronomy display tools can be a frustrating experience in terms of speed and ergonomics, especially on mobile devices. In this paper, we present a high performance, versatile and robust client-server system for remote visualization and analysis of extremely large scientific images. Applications of this work include survey image quality control, interactive data query and exploration, citizen science, as well as public outreach. The proposed software is entirely open source and is designed to be generic and applicable to a variety of datasets. It provides access to floating point data at terabyte scales, with the ability to precisely adjust image settings in real-time. The proposed clients are light-weight, platform-independent web applications built on standard HTML5 web technologies and compatible with both touch and mouse-based devices. We put the system to the test and assess the performance of the system and show that a single server can comfortably handle more than a hundred simultaneous users accessing full precision 32 bit astronomy data.

A Grand Vision for European Astronomy

Science.gov (United States)

2007-09-01

, community-based Infrastructure Roadmap, crucial to keep Europe at the forefront of astronomical research," says de Zeeuw. ESO PR Photo 44a/07 European astronomy today is fully competitive on the global scene and is at the forefront in many domains with such breakthroughs as the first detection of a planet around a sun-like star, the successful landing on Titan, the proof that a massive black hole exists in the centre of our own Galaxy, the discovery of gravitational arcs around galaxy clusters, and the proof that most Gamma Ray Bursts are caused by huge exploding stars. The rise of European astronomy to this top position by the end of last century has been achieved through extensive cooperation and coordination of efforts, in particular through ESO for optical astronomy and ESA for space astronomy. To strengthen this position and to extend it to all branches of astronomy and all nations of the new Europe, a group of European funding agencies set up the ASTRONET programme with the goal to establish a comprehensive long-term development plan of European astronomy. ASTRONET therefore covers all astrophysical domains from cosmology to the Solar system, and every observing window, from space and from the ground, and from electromagnetic radiation to particles and gravitational waves. It addresses the whole astronomical 'food chain' from infrastructure and technology development to observation, data access, modelling and theory, and the human resources needed to make it all work. This effort is quite similar in scope to the 'decadal surveys' conducted in the USA over the last half-century, but unlike its American counterpart, ASTRONET was set up directly by the national funding agencies, with strong support from the European Commission. "A shared long-term Science Vision for European astronomy is the fundamental first step in the process, soon to be followed by a detailed infrastructure and technology development roadmap," says Johannes Andersen (NOTSA, Denmark), the ASTRONET

Green function iterative solution of ground state wave function for Yukawa potential

International Nuclear Information System (INIS)

Zhang Zhao

2003-01-01

The newly developed single trajectory quadrature method is applied to solve central potentials. First, based on the series expansion method an exact analytic solution of the ground state for Hulthen potential and an approximate solution for Yukawa potential are obtained respectively. Second, the newly developed iterative method based on Green function defined by quadratures along the single trajectory is applied to solve Yukawa potential using the Coulomb solution and Hulthen solution as the trial functions respectively. The results show that a more proper choice of the trial function will give a better convergence. To further improve the convergence the iterative method is combined with the variational method to solve the ground state wave function for Yukawa potential, using variational solutions of the Coulomb and Hulthen potentials as the trial functions. The results give much better convergence. Finally, the obtained critical screen coefficient is applied to discuss the dissociate temperature of J/ψ in high temperature QGP

Introduction to methods of approximation in physics and astronomy

CERN Document Server

van Putten, Maurice H P M

2017-01-01

This textbook provides students with a solid introduction to the techniques of approximation commonly used in data analysis across physics and astronomy. The choice of methods included is based on their usefulness and educational value, their applicability to a broad range of problems and their utility in highlighting key mathematical concepts. Modern astronomy reveals an evolving universe rife with transient sources, mostly discovered - few predicted - in multi-wavelength observations. Our window of observations now includes electromagnetic radiation, gravitational waves and neutrinos. For the practicing astronomer, these are highly interdisciplinary developments that pose a novel challenge to be well-versed in astroparticle physics and data-analysis. The book is organized to be largely self-contained, starting from basic concepts and techniques in the formulation of problems and methods of approximation commonly used in computation and numerical analysis. This includes root finding, integration, signal dete...

The Space Vehicle--Teaching Physics through Astronomy.

Science.gov (United States)

Kibble, Bob

1991-01-01

Discussed are some areas of overlap between physics and astronomy. Topics include solar power, fusion reactions, atmospheric refraction, solar spectrum, Doppler effects, Hubble constant, quasars, redshift and the expanding universe, sunspots, sundial construction, solar spectroscopes, the moon, optics, wave theory, the history of science,…

Engineering uses of physics-based ground motion simulations

Science.gov (United States)

Baker, Jack W.; Luco, Nicolas; Abrahamson, Norman A.; Graves, Robert W.; Maechling, Phillip J.; Olsen, Kim B.

2014-01-01

This paper summarizes validation methodologies focused on enabling ground motion simulations to be used with confidence in engineering applications such as seismic hazard analysis and dynmaic analysis of structural and geotechnical systems. Numberical simullation of ground motion from large erthquakes, utilizing physics-based models of earthquake rupture and wave propagation, is an area of active research in the earth science community. Refinement and validatoin of these models require collaboration between earthquake scientists and engineering users, and testing/rating methodolgies for simulated ground motions to be used with confidence in engineering applications. This paper provides an introduction to this field and an overview of current research activities being coordinated by the Souther California Earthquake Center (SCEC). These activities are related both to advancing the science and computational infrastructure needed to produce ground motion simulations, as well as to engineering validation procedures. Current research areas and anticipated future achievements are also discussed.

Established Designs For Advanced Ground Based Astronomical Telescopes In The 1-meter To 4-meter Domain

Science.gov (United States)

Hull, Anthony B.; Barentine, J.; Legters, S.

2012-01-01

The same technology and analytic approaches that led to cost-effective unmitigated successes for the spaceborne Kepler and WISE telescopes are now being applied to meter-class to 4-meter-class ground telescopes, providing affordable solutions to ground astronomy, with advanced features as needed for the application. The range of optical and mechanical performance standards and features that can be supplied for ground astronomy shall be described. Both classical RC designs, as well as unobscured designs are well represented in the IOS design library, allowing heritage designs for both night time and day time operations, the latter even in the proximity of the sun. In addition to discussing this library of mature features, we will also describe a process for working with astronomers early in the definition process to provide the best-value solution. Solutions can include remote operation and astronomical data acquisition and transmission.

Astronomy Education in Morocco - New Project for Implementing Astronomy in High Schools

Science.gov (United States)

Darhmaoui, H.; Loudiyi, K.

2006-08-01

Astronomy education in Morocco, like in many developing countries, is not well developed and lacks the very basics in terms of resources, facilities and research. In 2004, the International Astronomical Union (IAU) signed an agreement of collaboration with Al Akhawayn University in Ifrane to support the continued, long-term development of astronomy and astrophysics in Morocco. This is within the IAU program "Teaching for Astronomy Development" (TAD). The initial focus of the program concentrated exclusively on the University's Bachelor of Science degree program. Within this program, and during two years, we were successful in providing adequate astronomy training to our physics faculty and few of our engineering students. We also offered our students and community general astronomy background through courses, invited talks and extra curricular activities. The project is now evolving towards a wider scope and seeks promoting astronomy education at the high school level. It is based on modules from the Hands on Universe (HOU) interactive astronomy program. Moroccan students will engage in doing observational astronomy from their PCs. They will have access to a world wide network of telescopes and will interact with their peers abroad. Through implementing astronomy education at this lower age, we foresee an increasing interest among our youth not only in astronomy but also in physics, mathematics, and technology. The limited astronomy resources, the lack of teachers experience in the field and the language barrier are amongst the difficulties that we'll be facing in achieving the objectives of this new program.

Designed microtremor array based actual measurement and analysis of strong ground motion at Palu city, Indonesia

Energy Technology Data Exchange (ETDEWEB)

Thein, Pyi Soe, E-mail: pyisoethein@yahoo.com [Geology Department, Yangon University (Myanmar); Pramumijoyo, Subagyo; Wilopo, Wahyu; Setianto, Agung [Geological Engineering Department, Gadjah Mada University (Indonesia); Brotopuspito, Kirbani Sri [Physics Department, Gadjah Mada University (Indonesia); Kiyono, Junji; Putra, Rusnardi Rahmat [Graduate School of Global Environmental Studies, Kyoto University (Japan)

2015-04-24

In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ≤ 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green’s function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake.

The Cambridge encyclopaedia of astronomy

CERN Document Server

1977-01-01

Astronomy has been transformed in the last two decades by a series of dramatic discoveries that have left most reference books completely out of date. The Cambridge Encyclopaedia of Astronomy presents a broadly based survey of the whole of astronomy which places emphasis on these critical new findings.

GPM GROUND VALIDATION CONICAL SCANNING MILLIMETER-WAVE IMAGING RADIOMETER (COSMIR) MC3E V1

Data.gov (United States)

National Aeronautics and Space Administration — The GPM Ground Validation Conical Scanning Millimeter-wave Imaging Radiometer (COSMIR) MC3E dataset used the Conical Scanning Millimeter-wave Imaging Radiometer...

Quickly Creating Interactive Astronomy Illustrations

Science.gov (United States)

Slater, Timothy F.

2015-01-01

An innate advantage for astronomy teachers is having numerous breathtaking images of the cosmos available to capture students' curiosity, imagination, and wonder. Internet-based astronomy image libraries are numerous and easy to navigate. The Astronomy Picture of the Day, the Hubble Space Telescope image archive, and the NASA Planetary…

Explorers of the Southern Sky: A History of Australian Astronomy

Science.gov (United States)

Haynes, Raymond; Haynes, Roslynn D.; Malin, David; McGee, Richard

1996-06-01

This well-illustrated volume is the most comprehensive account of Australian astronomy to date. It is both an indispensable reference book on the history of astronomy in Australia, and a highly readable study of a scientific discipline in the context of emerging nationhood. It covers not only the science, but the individuals involved and the social and economic climate in which they worked. Starting from the ancient Aboriginal beliefs about the Sky World - the earliest known astronomy, anywhere in the world - we are led through to the most exciting high-tech current and projected research being carried out at Australia's world-class national astronomy facilities, and by groups in Australian universities. All branches of astronomy are covered - optical, infrared, X-ray, gamma-ray, microwave, gravitational wave and theoretical - including the contribution of amateur astronomers. The non-technical language, many illustrations, and explanatory figures, ensure that this guide will appeal to a wide range of readers - including professional astronomers, historians of science, students, amateur astronomers and general readers.

Instrumentation for Kinetic-Inductance-Detector-Based Submillimeter Radio Astronomy

Science.gov (United States)

Duan, Ran

A substantial amount of important scientific information is contained within astronomical data at the submillimeter and far-infrared (FIR) wavelengths, including information regarding dusty galaxies, galaxy clusters, and star-forming regions; however, these wavelengths are among the least-explored fields in astronomy because of the technological difficulties involved in such research. Over the past 20 years, considerable efforts have been devoted to developing submillimeter- and millimeter-wavelength astronomical instruments and telescopes. The number of detectors is an important property of such instruments and is the subject of the current study. Future telescopes will require as many as hundreds of thousands of detectors to meet the necessary requirements in terms of the field of view, scan speed, and resolution. A large pixel count is one benefit of the development of multiplexable detectors that use kinetic inductance detector (KID) technology. This dissertation presents the development of a KID-based instrument including a portion of the millimeter-wave bandpass filters and all aspects of the readout electronics, which together enabled one of the largest detector counts achieved to date in submillimeter-/millimeter-wavelength imaging arrays: a total of 2304 detectors. The work presented in this dissertation has been implemented in the MUltiwavelength Submillimeter Inductance Camera (MUSIC), a new instrument for the Caltech Submillimeter Observatory (CSO).

Astronomy in the City for Astronomy Education

Science.gov (United States)

Ros, Rosa M.; Garc, Beatriz

2016-10-01

Astronomy is part of our culture. Astronomy cannot be isolated in a classroom, it has to be integrated in the normal life of teachers and students. ``Astronomy in the city'' is an important part of NASE (Network for Astronomy School Education) (Ros & Hemenway 2012). In each NASE course we introduce a ``working group session'' chaired by a local expert in cultural astronomy. The chair introduces several examples of astronomy in their city and after that, the participants have the opportunity to discuss and mention several similar examples. After this session all participants visit one or two sites proposed and introduced by the chair. After more than 5 years using this method we visited and discovered several examples of astronomy in the city: •Astronomy in ancient typical clothes. •Archaeological temples oriented according to the sunrise or set. •Petroglyphs with astronomical meaning. •Astronomy in monuments. •Sundials. •Oriented Colonial churches. •Astronomy in Souvenirs. In any case, teachers and students discover that Astronomy is part of their everyday life. They can take into account the Sun's path when they park their car or when they take a bus ``what is the best part in order to be seat in the shadow during the journey?'' The result is motivation to go with ``open eyes'' when they are in the street and they try to get more and more information about their surroundings. In summary, one of the main activities is to introduce local cultural aspects in NASE astronomy courses. The participants can discover a new approach to local culture from an astronomical point of view.

Comprehensive study of ULF upstream waves observed in the topside ionosphere by CHAMP and on the ground

Directory of Open Access Journals (Sweden)

B. Heilig

2007-03-01

Full Text Available Based on magnetic field measurements from the satellite CHAMP, a detailed picture could be obtained of the upstream wave (UW distribution in the topside ionosphere. The low, near-polar orbit of CHAMP, covering all local times, allows the global distribution of this type of pulsation to be revealed. The observations from space are compared to recordings of the ground-based MM100 meridional array covering the latitude range 66° to 42° in magnetic coordinates. UWs show up very clearly in the compressional component of the satellite magnetic field data, whereas on the ground, their signature is found in the H component, but it is mixed with oscillations from field line resonant pulsations. Here we first introduce a procedure for an automated detection of UW signatures, both in ground and space data. Then a statistical analysis is presented of UW pulsations recorded during a 132-day period, centred on the autumn 2001 equinox. Observations in the top-side ionosphere reveal a clear latitudinal distribution of the amplitudes. Largest signals are observed at the equator. Minima show up at about 40° latitude. The coherence between ground and satellite wave signatures is high over wide latitude and longitude ranges. We make suggestions about the entry mechanism of UWs from the foreshock region into the magnetosphere. The clear UW signature in satellite recordings between −60° and 60° latitude allows for detailed investigations of the dependence on solar wind conditions. We test the control of solar wind speed, interplanetary magnetic field strength and cone angle on UWs. For the first time, it is possible to derive details of the Doppler-shift effect by modifying the UW frequency from direct observations. The results reconcile foreshock wave generation predictions with near-Earth observations.

Review of decametric radio astronomy - instruments and science

International Nuclear Information System (INIS)

Erickson, W.C.; Cane, H.V.

1987-01-01

The techniques and instruments used in Galactic and extragalactic radio astronomy at dkm wavelengths are surveyed, and typical results are summarized. Consideration is given to the large specialized phased arrays used for early surveys, the use of wideband elements to increase frequency agility, experimental VLBI observations, and limitations on ground-based observations below about 10 MHz (where the proposed LF Space Array, with resolution 0.5-5 arcmin, could make a major contribution). Observations discussed cover the Galactic center, the Galactic background radiation, SNRs, compact Galactic sources, the ISM, and large extragalactic sources. 38 references

Satellite and Ground Signatures of Kinetic and Inertial Scale ULF Alfven Waves Propagating in Warm Plasma in Earth's Magnetosphere

Science.gov (United States)

Rankin, R.; Sydorenko, D.

2015-12-01

Results from a 3D global numerical model of Alfven wave propagation in a warm multi-species plasma in Earth's magnetosphere are presented. The model uses spherical coordinates, accounts for a non-dipole magnetic field, vertical structure of the ionosphere, and an air gap below the ionosphere. A realistic density model is used. Below the exobase altitude (2000 km) the densities and the temperatures of electrons, ions, and neutrals are obtained from the IRI and MSIS models. Above the exobase, ballistic (originating from the ionosphere and returning to ionosphere) and trapped (bouncing between two reflection points above the ionosphere) electron populations are considered similar to [Pierrard and Stegen (2008), JGR, v.113, A10209]. Plasma parameters at the exobase provided by the IRI are the boundary conditions for the ballistic electrons while the [Carpenter and Anderson (1992), JGR, v.97, p.1097] model of equatorial electron density defines parameters of the trapped electron population. In the simulations that are presented, Alfven waves with frequencies from 1 Hz to 0.01 Hz and finite azimuthal wavenumbers are excited in the magnetosphere and compared with Van Allen Probes data and ground-based observations from the CARISMA array of ground magnetometers. When short perpendicular scale waves reflect form the ionosphere, compressional Alfven waves are observed to propagate across the geomagnetic field in the ionospheric waveguide [e.g., Lysak (1999), JGR, v.104, p.10017]. Signals produced by the waves on the ground are discussed. The wave model is also applied to interpret recent Van Allen Probes observations of kinetic scale ULF waves that are associated with radiation belt electron dynamics and energetic particle injections.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Author Affiliations. Akshaya Rane1 2 Duncan Lorimer1 2. Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506, USA. Center for Gravitational Waves and Cosmology, Chestnut Ridge Research Building, Morgantown, WV 26505, USA.

Coincident Detection Significance in Multimessenger Astronomy

Science.gov (United States)

Ashton, G.; Burns, E.; Dal Canton, T.; Dent, T.; Eggenstein, H.-B.; Nielsen, A. B.; Prix, R.; Was, M.; Zhu, S. J.

2018-06-01

We derive a Bayesian criterion for assessing whether signals observed in two separate data sets originate from a common source. The Bayes factor for a common versus unrelated origin of signals includes an overlap integral of the posterior distributions over the common-source parameters. Focusing on multimessenger gravitational-wave astronomy, we apply the method to the spatial and temporal association of independent gravitational-wave and electromagnetic (or neutrino) observations. As an example, we consider the coincidence between the recently discovered gravitational-wave signal GW170817 from a binary neutron star merger and the gamma-ray burst GRB 170817A: we find that the common-source model is enormously favored over a model describing them as unrelated signals.

The Effect of Solar Radiation on Radio Signal for Radio Astronomy Purposes

International Nuclear Information System (INIS)

Nor Hazmin Sabri; Atiq Wahidah Azlan; Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Zainol Abidin Ibrahim; Wan Zul Adli Wan Mokhtar

2015-01-01

Radio astronomy is a subfields of astronomy which is discovers the celestial objects at radio frequencies. Observation in radio astronomy is conducted using single antenna or array of antennas, known as radio telescope. Other than that, radio astronomy also holds an advantage over other alternatives to optical astronomy due to its capability of observing from the ground level. In this study, the effect of solar radiation that contributes the Radio Frequency Interferences (RFI) is reviewed. The low RFI level is required to set up the radio telescope for radio astronomy observation. The effect of solar radiation on radio signal was investigated by determining the RFI pattern using spectrum analyzer. The solar radiation data was obtained from weather station located at KUSZA Observatory, East Coast Environmental Research Institute (ESERI), UniSZA. We can conclude that the solar radiation factor give the minimum significant effect to radio signal. (author)

Overview of diffraction gratings technologies for space-flight satellites and astronomy

Science.gov (United States)

Cotel, Arnaud; Liard, Audrey; Desserouer, Frédéric; Bonnemason, Francis; Pichon, Pierre

2014-09-01

The diffraction gratings are widely used in Space-flight satellites for spectrograph instruments or in ground-based telescopes in astronomy. The diffraction gratings are one of the key optical components of such systems and have to exhibit very high optical performances. HORIBA Jobin Yvon S.A.S. (part of HORIBA Group) is in the forefront of such gratings development for more than 40 years. During the past decades, HORIBA Jobin Yvon (HJY) has developed a unique expertise in diffraction grating design and manufacturing processes for holographic, ruled or etched gratings. We will present in this paper an overview of diffraction grating technologies especially designed for space and astronomy applications. We will firstly review the heritage of the company in this field with the space qualification of different grating types. Then, we will describe several key grating technologies developed for specific space or astronomy projects: ruled blazed low groove density plane reflection grating, holographic blazed replica plane grating, high-groove density holographic toroidal and spherical grating and transmission Fused Silica Etched (FSE) grismassembled grating.

Cosmic Noise: The Pioneers of Early Radio Astronomy and Their Discoveries

Science.gov (United States)

Sullivan, Woodruff T., III

2012-01-01

Extraterrestrial radio waves (the galactic background), often referred to as "cosmic noise", were first detected accidentally by Karl Jansky at a frequency of 20 MHz in 1932, with significant followup by Grote Reber. Yet after World War II it was England and Australia that dominated the field. An entirely different sky from that of visual astronomy was revealed by the discoveries of solar noise, "radio stars” (discrete sources such as Cas A, Tau A, Cyg A, Cen A and Vir A), galactic noise, lunar and meteor radar experiments, the detection of the 21 cm hydrogen line, and eventually optical identifications such as the Crab Nebula and M87. Key players included wartime radar experts such as Stanley Hey (the British Army's Operational Research Group), Martin Ryle (Cambridge University), Bernard Lovell (Jodrell Bank) and Joe Pawsey (Radiophysics Lab, Sydney). Younger leaders also emerged such as Graham Smith, Tony Hewish, John Davies, "Chris" Christiansen, Bernie Mills, Paul Wild, and John Bolton. Some optical astronomers (Jan Oort, Henk van de Hulst, Jesse Greenstein, Rudolph Minkowski, and Walter Baade) were also extremely supportive. By the end of the postwar decade, radio astronomy was firmly established within the gamut of astronomy, although very few of its practitioners had been trained as astronomers. I will also trace the technical and social aspects of this wholly new type of astronomy, with special attention on military and national influences. I argue that radio astronomy represents one of the key developments in twentieth century astronomy not only because of its own discoveries, but also its pathfinding for the further opening the electromagnetic spectrum. This study is based on exhaustive archival research and over one hundred interviews with pioneering radio astronomers. Full details are available in the book "Cosmic Noise: A History of Early Radio Astronomy" (Cambridge Univ. Pr.).

Development of HgCdTe large format MBE arrays and noise-free high speed MOVPE EAPD arrays for ground based NIR astronomy

Science.gov (United States)

Finger, G.; Baker, I.; Downing, M.; Alvarez, D.; Ives, D.; Mehrgan, L.; Meyer, M.; Stegmeier, J.; Weller, H. J.

2017-11-01

Large format near infrared HgCdTe 2Kx2K and 4Kx4K MBE arrays have reached a level of maturity which meets most of the specifications required for near infrared (NIR) astronomy. The only remaining problem is the persistence effect which is device specific and not yet fully under control. For ground based multi-object spectroscopy on 40 meter class telescopes larger pixels would be advantageous. For high speed near infrared fringe tracking and wavefront sensing the only way to overcome the CMOS noise barrier is the amplification of the photoelectron signal inside the infrared pixel by means of the avalanche gain. A readout chip for a 320x256 pixel HgCdTe eAPD array will be presented which has 32 parallel video outputs being arranged in such a way that the full multiplex advantage is also available for small sub-windows. In combination with the high APD gain this allows reducing the readout noise to the subelectron level by applying nondestructive readout schemes with subpixel sampling. Arrays grown by MOVPE achieve subelectron readout noise and operate with superb cosmetic quality at high APD gain. Efforts are made to reduce the dark current of those arrays to make this technology also available for large format focal planes of NIR instruments offering noise free detectors for deep exposures. The dark current of the latest MOVPE eAPD arrays is already at a level adequate for noiseless broad and narrow band imaging in scientific instruments.

Sketches of a hammer-impact, spiked-base, shear-wave source

Science.gov (United States)

Hasbrouck, W.P.

1983-01-01

Generation of shear waves in shallow seismic investigations (those to depths usually less than 100 m) can be accomplished by horizontally striking with a hammer either the end of a wood plank or metal structure embedded at the ground surface. The dimensioned sketches of this report are of a steel, hammer-impact, spiked-base, shear-wave source. It has been used on outcrops and in a desert environment and for conducting experiments on the effect of rotating source direction.

Back radiation suppression through a semi-transparent round ground plane for a mm-Wave monopole antenna

KAUST Repository

Klionovski, Kirill; Farooqui, Muhammad Fahad; Shamim, Atif

2017-01-01

Omnidirectional radiation pattern with minimum backward radiation is highly desirable for millimeter-wave telecommunication antennas. In this work, we propose a round, semitransparent ground plane of radius 0.8λ with uniform impedance distribution that can reduce the back radiation of a monopole antenna by 8.8 dB as compared with a similar sized metallic ground plane. The value of uniform impedance is obtained through analytical optimization by using asymptotic expressions in the Kirchhoff approximation of the radiation pattern of a toroidal wave scattered by a round semitransparent ground plane. The semitransparent ground plane has been realized using a low-cost carbon paste on a Kapton film. Experimental results match closely with those of simulations and validate the overall concept.

Back radiation suppression through a semi-transparent round ground plane for a mm-Wave monopole antenna

KAUST Repository

Klionovski, Kirill

2017-10-25

Omnidirectional radiation pattern with minimum backward radiation is highly desirable for millimeter-wave telecommunication antennas. In this work, we propose a round, semitransparent ground plane of radius 0.8λ with uniform impedance distribution that can reduce the back radiation of a monopole antenna by 8.8 dB as compared with a similar sized metallic ground plane. The value of uniform impedance is obtained through analytical optimization by using asymptotic expressions in the Kirchhoff approximation of the radiation pattern of a toroidal wave scattered by a round semitransparent ground plane. The semitransparent ground plane has been realized using a low-cost carbon paste on a Kapton film. Experimental results match closely with those of simulations and validate the overall concept.

Flapping current sheet with superposed waves seen in space and on the ground

Science.gov (United States)

Wang, Guoqiang; Volwerk, Martin; Nakamura, Rumi; Boakes, Peter; Zhang, Tielong; Ge, Yasong; Yoshikawa, Akimasa; Baishev, Dmitry

2015-04-01

A wavy current sheet event observed on 15th of October 2004 between 1235 and 1300 UT has been studied by using Cluster and ground-based magnetometer data. Waves propagating from the tail centre to the duskside flank with a period ~30 s and wavelength ~1 RE, are superimposed on a flapping current sheet, accompanied with a bursty bulk flow (BBF). Three Pi2 pulsations, with onset at ~1236, ~1251 and ~1255 UT, respectively, are observed at the Tixie (TIK) station located near the foot-points of Cluster. The mechanism creating the Pi2 (period ~40 s) onset at ~1236 UT is unclear. The second Pi2 (period ~90 s, onset at ~1251 UT) is associated with a strong field-aligned current, which has a strong transverse component of the magnetic field, observed by Cluster with a time delay ~60 s. We suggest that it is caused by bouncing Alfvén waves between the northern and southern ionosphere which transport the field-aligned current. For the third Pi2 (period ~60 s) there is almost no damping at the first three periods. They occur in conjunction with periodic field-aligned currents one-on-one with 72s delay. We suggest that it is generated by these periodic field-aligned currents. We conclude that the strong field-aligned currents generated in the plasma sheet during flapping with superimposed higher frequency waves can drive Pi2 pulsations on the ground, and periodic field-aligned currents can even control the period of the Pi2s.

Handling Qualities Flight Testing of the Stratospheric Observatory for Infrared Astronomy (SOFIA)

Science.gov (United States)

Glaser, Scott T.; Strovers, Brian K.

2011-01-01

Airborne infrared astronomy has a long successful history, albeit relatively unknown outside of the astronomy community. A major problem with ground based infrared astronomy is the absorption and scatter of infrared energy by water in the atmosphere. Observing the universe from above 40,000 ft puts the observation platform above 99% of the water vapor in the atmosphere, thereby addressing this problem at a fraction of the cost of space based systems. The Stratospheric Observatory For Infrared Astronomy (SOFIA) aircraft is the most ambitious foray into the field of airborne infrared astronomy in history. Using a 747SP (The Boeing Company, Chicago, Illinois) aircraft modified with a 2.5m telescope located in the aft section of the fuselage, the SOFIA endeavors to provide views of the universe never before possible and at a fraction of the cost of space based systems. The modification to the airplane includes moveable doors and aperture that expose the telescope assembly. The telescope assembly is aimed and stabilized using a multitude of on board systems. This modification has the potential to cause aerodynamic anomalies that could induce undesired forces either at the cavity itself or indirectly due to interference with the empennage, both of which could cause handling qualities issues. As a result, an extensive analysis and flight test program was conducted from December 2009 through March 2011. Several methods, including a Lower Order Equivalent Systems analysis and pilot assessment, were used to ascertain the effects of the modification. The SOFIA modification was found to cause no adverse handling qualities effects and the aircraft was cleared for operational use. This paper discusses the history and modification to the aircraft, development of test procedures and analysis, results of testing and analysis, lessons learned for future projects and justification for operational certification.

Evolution of double white dwarf binaries undergoing direct-impact accretion: Implications for gravitational wave astronomy

Science.gov (United States)

Kremer, Kyle; Breivik, Katelyn; Larson, Shane L.; Kalogera, Vassiliki

2017-01-01

For close double white dwarf binaries, the mass-transfer phenomenon known as direct-impact accretion (when the mass transfer stream impacts the accretor directly rather than forming a disc) may play a pivotal role in the long-term evolution of the systems. In this analysis, we explore the long-term evolution of white dwarf binaries accreting through direct-impact and explore implications of such systems to gravitational wave astronomy. We cover a broad range of parameter space which includes initial component masses and the strength of tidal coupling, and show that these systems, which lie firmly within the LISA frequency range, show strong negative chirps which can last as long as several million years. Detections of double white dwarf systems in the direct-impact phase by detectors such as LISA would provide astronomers with unique ways of probing the physics governing close compact object binaries.

The Evolution of Spacelab Ultraviolet Astronomy Missions from OSS-3 through -7 to Astro-1

Science.gov (United States)

Gull, Theodore

2018-01-01

In the 1960s and 1970s, NASA was building towards a robust program in space astronomy. An evolutionary step from ground-based astronomy to space astronomy was human operation of space telescopes as astronomy in general evolved from astronomers directly at the telescope to application of computers and long distance communications to control to operate remote telescopes. Today ground-based telescopes and space observatories from cubesats to the Hubble Space Telescope and soon the James Webb Space Telescope are routinely operated remotely.In response to the Spacelab Announcement of Opportunity in the early 1980s, three ultraviolet experiments – the Hopkins Ultraviolet Telescope, the Ultraviolet Imaging Telescope and the Wisconsin Ultraviolet PhotoPolarimetry Experiment -- all instruments derived from multiple sounding rocket flights--were selected to fly as an integrated payload attached to a space shuttle. The justification for professional astronomers, both as Mission Specialists from the astronaut cadre and Payload Specialists from the instrument teams, was built to ensure key technical skills both of the science and the instruments. Bundled together as OSS-3 through -7 flights focused on Comet Halley, the experiments went through many changes and delays as a pathfinder for an anticipated series of attached astronomy payloads.By 1986, the five-flight mission had evolved into two missions, Astro-1 dedicated primarily to observe Halley’s Comet in early March 1986 and Astro-2 to fly about one year later. Due to the Challenger disaster 35 days before scheduled launch of Astro-1, the mission went through an initial cancellation and then re-scheduling once the instrument complement of Astro-1 was expanded to include Broad Band X-ray Telescope with emphasis on studying SN1987A. Ultimately Astro-1 flew in December 1990 partnered with an X-ray experiment focused on SN1987A.The nine-day mission was mostly successful despite multiple technical issues overcome by the NASA

Astronomy Landscape in Africa

Science.gov (United States)

Nemaungani, Takalani

2015-01-01

The vision for astronomy in Africa is embedded in the African Space Policy of the African Union in early 2014. The vision is about positioning Africa as an emerging hub for astronomy sciences and facilities. Africa recognized the need to take advantage of its natural resource, the geographical advantage of the clear southern skies and pristine sites for astronomy. The Pan African University (PAU) initiative also presents an opportunity as a post-graduate training and research network of university nodes in five regions of Africa and supported by the African Union. The Southern African node based in South Africa concentrates on space sciences which also includes astronomy. The PAU aims to provide the opportunity for advanced graduate training and postgraduate research to high-performing African students. Objectives also include promoting mobility of students and teachers and harmonizing programs and degrees.A number of astronomy initiatives have burgeoned in the Southern African region and these include the Southern Africa Largest Optical Telescope (SALT), HESS (High Energy Stereoscopic System), the SKA (Square Kilometre Array) and the AVN (African Very Long Baseline Interferometer Network). There is a growing appetite for astronomy sciences in Africa. In East Africa, the astronomy community is well organized and is growing - the East African Astronomical society (EAAS) held its successful fourth annual conference since 2010 on 30 June to 04 July 2014 at the University of Rwanda. Centred around the 'Role of Astronomy in Socio-Economic Transformation,' this conference aimed at strengthening capacity building in Astronomy, Astrophysics and Space Science in general, while providing a forum for astronomers from the region to train young and upcoming scientists.

The dawn of gravitational wave astronomy

CERN Multimedia

CERN. Geneva

2016-01-01

On Sep 14 2015, gravitational waves were for the first time detected directly. This observation by the LIGO interferometric detectors marks the dawn of a new era in our observational study of the cosmos as a qualitatively new window to its exploration has been opened. This talk reviews some of the fundamental concepts of gravitational waves and the methodology employed for their observation. The first event, dubbed GW150914, and the properties of its source, as inferred from the observation, will be discussed. The talk concludes with a selected set of the most important topics where we expect gravitational-wave observations to deepen and either challenge or confirm our present understanding of the laws and the history of our universe.

Coincident searches between high energy neutrinos and gravitational waves with ANTARES, VIRGO and LIGO detectors

International Nuclear Information System (INIS)

Bouhou, B.

2012-01-01

The aim of this work is the joint detection of gravitational waves and high energy neutrinos in a multi-messengers context. The neutrino and gravitational waves astronomies are still in the phase of development, but they are expected to play a fundamental role in the future. In fact, these messengers can travel big distances because of their weak interaction with matter (contrary to photons that at high energy are rapidly absorbed) without being affected by magnetic fields (contrary to charged cosmic rays). They can also escape dense media and provide information on the processes taking place in the heart of astrophysics sources. Particularly, GW+HEN multi-messenger astronomy may open a new observational window on the Universe. ANTARES collaboration has built a telescope of area 0.1 km 2 in the Mediterranean Sea for the detection of high energy neutrinos. This is the most sensitive telescope for the observed part of the sky. LIGO and VIRGO interferometers are ground-based detector for direct observation of gravitational waves, installed in Europe and the USA respectively. Instruments ANTARES, VIRGO and LIGO offer unrivaled sensitivity in the area of joint observation. The first chapter of this thesis introduces the theoretical motivations for GW+HEN search by developing different emission scenarios. The second and third chapters we give an overview of the experiments and review the data analysis tools. The fourth and fifth chapters of this work present the results of the analysis of the combined data from ANTARES, VIRGO and LIGO taken separately in 2007 and 2009-2010. (author)

Astronomy, Astrology, and Medicine

Science.gov (United States)

Greenbaum, Dorian Gieseler

Astronomy and astrology were combined with medicine for thousands of years. Beginning in Mesopotamia in the second millennium BCE and continuing into the eighteenth century, medical practitioners used astronomy/astrology as an important part of diagnosis and prescription. Throughout this time frame, scientists cited the similarities between medicine and astrology, in addition to combining the two in practice. Hippocrates and Galen based medical theories on the relationship between heavenly bodies and human bodies. In an enduring cultural phenomenon, parts of the body as well as diseases were linked to zodiac signs and planets. In Renaissance universities, astronomy and astrology were studied by students of medicine. History records a long tradition of astrologer-physicians. This chapter covers the topic of astronomy, astrology, and medicine from the Old Babylonian period to the Enlightenment.

Environmental Effects for Gravitational-wave Astrophysics

International Nuclear Information System (INIS)

Barausse, Enrico; Cardoso, Vitor; Pani, Paolo

2015-01-01

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

Ground waves caused by gas cloud explosions and their effects on nuclear power plant structures

International Nuclear Information System (INIS)

Werkle, H.; Waas, G.

1983-01-01

The response of embedded structures to ground waves caused by the explosion of a gas cloud is studied. In the first step, the free field ground motion is analyzed; then the response of a PWR-building is computed. The analysis of the free-field motion is performed using a two-dimensional plane strain model, whereas the interaction problem of the structure excited by the free-field motion is investigated using an axisymmetric three-dimensional model. The soil is assumed to be viscoelastic and horizontally layered. The equations of motion for the viscoelastic continuum are solved in the frequency domain by a semianalytic method. The travelling surface loads from air pressure waves are represented by superposition of line loads. The superposition takes advantage of the mathematical properties of the Fourier transforms. Explicit ring load solutions are used to solve the three-dimensional interaction problem of a rigid embedded circular foundation excited by a two-dimensional wave field of Rayleigh wave type. (orig./WL)

Ground-based acoustic parametric generator impact on the atmosphere and ionosphere in an active experiment

Directory of Open Access Journals (Sweden)

Y. G. Rapoport

2017-01-01

Full Text Available We develop theoretical basics of active experiments with two beams of acoustic waves, radiated by a ground-based sound generator. These beams are transformed into atmospheric acoustic gravity waves (AGWs, which have parameters that enable them to penetrate to the altitudes of the ionospheric E and F regions where they influence the electron concentration of the ionosphere. Acoustic waves are generated by the ground-based parametric sound generator (PSG at the two close frequencies. The main idea of the experiment is to design the output parameters of the PSG to build a cascade scheme of nonlinear wave frequency downshift transformations to provide the necessary conditions for their vertical propagation and to enable penetration to ionospheric altitudes. The PSG generates sound waves (SWs with frequencies f1 = 600 and f2 = 625 Hz and large amplitudes (100–420 m s−1. Each of these waves is modulated with the frequency of 0.016 Hz. The novelty of the proposed analytical–numerical model is due to simultaneous accounting for nonlinearity, diffraction, losses, and dispersion and inclusion of the two-stage transformation (1 of the initial acoustic waves to the acoustic wave with the difference frequency Δf = f2 − f1 in the altitude ranges 0–0.1 km, in the strongly nonlinear regime, and (2 of the acoustic wave with the difference frequency to atmospheric acoustic gravity waves with the modulational frequency in the altitude ranges 0.1–20 km, which then reach the altitudes of the ionospheric E and F regions, in a practically linear regime. AGWs, nonlinearly transformed from the sound waves, launched by the two-frequency ground-based sound generator can increase the transparency of the ionosphere for the electromagnetic waves in HF (MHz and VLF (kHz ranges. The developed theoretical model can be used for interpreting an active experiment that includes the PSG impact on the atmosphere–ionosphere system

Infrared Astronomy Professional Development for K-12 Educators: WISE Telescope

Science.gov (United States)

Borders, Kareen; Mendez, B. M.

2010-01-01

K-12 educators need effective and relevant astronomy professional development. WISE Telescope (Wide-Field Infrared Survey Explorer) and Spitzer Space Telescope Education programs provided an immersive teacher professional development workshop at Arecibo Observatory in Puerto Rico during the summer of 2009. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of WISE lenticulars and diagramming of infrared data, listening to light by using speakers hooked up to photoreceptor cells, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars. We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development. Funding was provided by WISE Telescope, Spitzer Space Telescope, Starbucks, Arecibo Observatory, the American Institute of Aeronautics and Astronautics, and the Washington Space Grant Consortium.

Blazing the Trail for Astronomy Education Research

Science.gov (United States)

Bailey, Janelle M.; Lombardi, Doug

2015-01-01

Education research has long considered student learning of topics in astronomy and the space sciences, but astronomy education research as a sub-field of discipline-based education research is relatively new. Driven by a growing interest among higher education astronomy educators in improving the general education, introductory science survey…

Ground cross-modal impedance as a tool for analyzing ground/plate interaction and ground wave propagation.

Science.gov (United States)

Grau, L; Laulagnet, B

2015-05-01

An analytical approach is investigated to model ground-plate interaction based on modal decomposition and the two-dimensional Fourier transform. A finite rectangular plate subjected to flexural vibration is coupled with the ground and modeled with the Kirchhoff hypothesis. A Navier equation represents the stratified ground, assumed infinite in the x- and y-directions and free at the top surface. To obtain an analytical solution, modal decomposition is applied to the structure and a Fourier Transform is applied to the ground. The result is a new tool for analyzing ground-plate interaction to resolve this problem: ground cross-modal impedance. It allows quantifying the added-stiffness, added-mass, and added-damping from the ground to the structure. Similarity with the parallel acoustic problem is highlighted. A comparison between the theory and the experiment shows good matching. Finally, specific cases are investigated, notably the influence of layer depth on plate vibration.

Ground eigenvalue and eigenfunction of a spin-weighted spheroidal wave equation in low frequencies

Institute of Scientific and Technical Information of China (English)

Tang Wen-Lin; Tian Gui-Hua

2011-01-01

Spin-weighted spheroidal wave functions play an important role in the study of the linear stability of rotating Kerr black holes and are studied by the perturbation method in supersymmetric quantum mechanics. Their analytic ground eigenvalues and eigenfunctions are obtained by means of a series in low frequency. The ground eigenvalue and eigenfunction for small complex frequencies are numerically determined.

Possible Space-Based Gravitational-Wave Observatory Mission Concept

Science.gov (United States)

Livas, Jeffrey C.

2015-08-01

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 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.

Managing Astronomy Research Data: Data Practices in the Sloan Digital Sky Survey and Large Synoptic Survey Telescope Projects

Science.gov (United States)

Sands, Ashley Elizabeth

2017-01-01

Ground-based astronomy sky surveys are massive, decades-long investments in scientific data collection. Stakeholders expect these datasets to retain scientific value well beyond the lifetime of the sky survey. However, the necessary investments in knowledge infrastructures for managing sky survey data are not yet in place to ensure the long-term…

New developments of radio-astronomy in the sub-mmwave region

International Nuclear Information System (INIS)

Matthews, H.E.

1989-01-01

Astronomy at submillimeter wavelengths is a technically demanding discipline which is coming of age through the recent construction of several large ground-based facilities and continuing advances in receiver technology. The current status of the field is reviewed with attention being paid particularly to the potential contributions to astrophysics and to the major difficulties facing the observer at these wavelengths. The results of surveys for molecular transitions and examples of the uses of such lines in determining excitation and other parameters of circum- and interstellar material is discussed. Observations of continuum radiation, principally of cold dust, is also touched upon. Both line and continuum studies have great potential at these wavelengths in the study of protostellar objects, as well as in the late stages of stellar evolution. Prospects for the future development of sub-mm astronomy are bright; plans to overcome the limitations imposed by the atmosphere using satellite technology, and to increase angular resolution by the use of interferometry are reviewed

Exploration of deep S-wave velocity structure using microtremor array technique to estimate long-period ground motion

International Nuclear Information System (INIS)

Sato, Hiroaki; Higashi, Sadanori; Sato, Kiyotaka

2007-01-01

In this study, microtremor array measurements were conducted at 9 sites in the Niigata plain to explore deep S-wave velocity structures for estimation of long-period earthquake ground motion. The 1D S-wave velocity profiles in the Niigata plain are characterized by 5 layers with S-wave velocities of 0.4, 0.8, 1.5, 2.1 and 3.0 km/s, respectively. The depth to the basement layer is deeper in the Niigata port area located at the Japan sea side of the Niigata plain. In this area, the basement depth is about 4.8 km around the Seirou town and about 4.1 km around the Niigata city, respectively. These features about the basement depth in the Niigata plain are consistent with the previous surveys. In order to verify the profiles derived from microtremor array exploration, we estimate the group velocities of Love wave for four propagation paths of long-period earthquake ground motion during Niigata-ken tyuetsu earthquake by multiple filter technique, which were compared with the theoretical ones calculated from the derived profiles. As a result, it was confirmed that the group velocities from the derived profiles were in good agreement with the ones from long-period earthquake ground motion records during Niigata-ken tyuetsu earthquake. Furthermore, we applied the estimation method of design basis earthquake input for seismically isolated nuclear power facilities by using normal mode solution to estimate long-period earthquake ground motion during Niigata-ken tyuetsu earthquake. As a result, it was demonstrated that the applicability of the above method for the estimation of long-period earthquake ground motion were improved by using the derived 1D S-wave velocity profile. (author)

NRAO Response to NSF Senior Review of Astronomy Facilities

Science.gov (United States)

2006-11-01

The National Science Foundation's (NSF) Astronomy Senior Review Committee report (pdf file), released today, made major recommendations for restructuring the NSF's ground-based astronomy efforts, including significant changes for the National Radio Astronomy Observatory (NRAO). The committee's report urged that leadership in radio astronomy, including millimeter- and submillimeter-wave observatories, "remain centered at NRAO as it is, by far, the largest radio astronomy organization in the world." The report praised the record of management of NRAO and the scientific capabilities of the Atacama Large Millimeter/submillimeter Array (ALMA), the Expanded Very Large Array (EVLA), the Robert C. Byrd Green Bank Telescope (GBT), and the Very Long Baseline Array (VLBA). However, the report also recommended that some reductions and changes occur at the NRAO by 2011. Specifically, the report recommended that: (a) VLBA operations make a transition to a significant reliance on international funding or risk closure; (b) GBT operations costs be reduced; and (c) NRAO scientific staff costs be reduced. "The Senior Review Committee had the very difficult task of reconciling the needs of current facilities and funding new facilities for the future of astronomy. We appreciate their efforts and look forward to working with the NSF to ensure that the valuable and unique research capabilities of our NRAO telescopes continue to serve the astronomical community," said Dr. Fred K.Y. Lo, NRAO Director. The VLBA provides the greatest angular resolution, or ability to see fine detail, of any telescope in the world, greatly exceeding the capabilities of the Hubble Space Telescope and the future Square Kilometre Array. The committee recognized that, "if the VLBA is closed, a unique capability would likely be lost for decades." "The VLBA is used by scientists from around the world because of its unique capabilities. It has produced landmark research milestones and the committee recognized in its

Managing a big ground-based astronomy project: the Thirty Meter Telescope (TMT) project

Science.gov (United States)

Sanders, Gary H.

2008-07-01

TMT is a big science project and its scale is greater than previous ground-based optical/infrared telescope projects. This paper will describe the ideal "linear" project and how the TMT project departs from that ideal. The paper will describe the needed adaptations to successfully manage real world complexities. The progression from science requirements to a reference design, the development of a product-oriented Work Breakdown Structure (WBS) and an organization that parallels the WBS, the implementation of system engineering, requirements definition and the progression through Conceptual Design to Preliminary Design will be summarized. The development of a detailed cost estimate structured by the WBS, and the methodology of risk analysis to estimate contingency fund requirements will be summarized. Designing the project schedule defines the construction plan and, together with the cost model, provides the basis for executing the project guided by an earned value performance measurement system.

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

NARCIS (Netherlands)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Phythian-Adams, A.T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.T.; Aguiar, O. D.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Amariutei, D. V.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, R.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.; Belczynski, C.; 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, M.J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, C. D.; Blair, R. M.; Bloernen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, J.G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, T.C; Bondu, F.; Bonnand, R.; Bork, R.; Boschi, V.; Bose, S.; 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, A.D.; Brown, 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.; Calderon Bustillo, J.; Callister, T. A.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. Cerboni; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, D. 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, Qian; Chua, S. E.; Chung, E.S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P. -F.; Coila, A.; Collette, C. G.; Constancio, M., Jr.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, A.C.; 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, A.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.; Deleglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dereli, H.; Dergachev, V.A.; DeRosa, R. T.; Rosa, R.; DeSalvo, R.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Giovanni, M.G.; Di Lieto, A.; 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. M.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etze, T.; Evans, T. M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.M.; 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.; Fisher, R. P.; Flaminio, R.; Fletcher, M; Fournier, J. -D.; Franco, S; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Garnrnaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gatto, A.; Gaur, G.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, A.; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.P.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; Gonzalez, Idelmis G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Lee-Gosselin, M.; Gouaty, R.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.M.; 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.; Buffoni-Hall, R.; Hall, E. D.; Hammond, G.L.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, P.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, D.H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jimenez-Forteza, F.; Johnson, W.; Jones, I.D.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, K.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.H.; Kanner, J. B.; Karki, S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kefelian, F.; Kehl, M. S.; Keite, D.; Kelley, D. B.; Kells, W.; Kennedy, R.E.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khan., S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, C.; Kirmo, J.; Kina, K.; Kim, Namjun; 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.; Krolak, 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, K.H.; Lee, M.H.; 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.; Logue, J.; Lombardi, A. L.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lueck, H.; Lundgren, A. P.; Luo, J.; Lynch, R.; Ma, Y.; MacDonald, T.T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magana-Sandoval, F.; Magee, R. M.; Mageswaran, M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandel, I.; Mandic, V.; MaIlga, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, 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.; 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.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, 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, J.C.; Moraru, D.; Gutierrez Moreno, M.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, S.D.; Mukherjee, S.; 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.; Gutierrez-Neri, M.; Neunzert, A.; Newton-Howes, 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'De, J.; Oelker, E.; Ogin, G. H.; Oh, J.; Oh, S. H.; Ohme, F.; Oliver, M. B.; 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.S; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Pereira, R.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.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Punturo, M.; Puppo, P.; Puerrer, 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.; Rosinska, D.; Rowan, S.; Ruediger, A.; Ruggi, P.; Ryan, K.A.; Sachdev, P.S.; Sadecki, T.; Sadeghian, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J; Schmidt, P.; Schnabel, R.B.; Schofield, R. M. S.; Schoenbeck, A.; Schreiber, K.E.C.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, M.S.; Sellers, D.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Setyawati, Y.; Sevigny, A.; Shaddock, D. A.; Shah, S.; Shahriar, M. S.; Shaltev, M.; Shao, Z.M.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sigg, D.; Silva, António Dias da; Simakov, D.; Singer, A; Singer, L. P.; Sillgh, A.; Singh, R.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, R. J. E.; 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, J.R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sutton, P. J.; Swinkels, B. L.; Szczepanczyk, M. J.; Tacca, M.D.; Talukder, D.; Tanner, D. B.; Tapai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, W.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.; Toeyrae, D.; Travasso, F.; Traylor, G.; Trifiro, 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 Bake, N.; Van Beuzekom, Martin; van den Brand, J. F. J.; Van Den Broeck, C.F.F.; Vander-Hyde, D. C.; van der Schaaf, L.; van der Sluys, M. V.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasuth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P.J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Vicere, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, MT; 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.M.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; White, D. J.; Whiting, B. F.; Williams, D.R.; 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.; Zadrozny, 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.; Zweizigl, J.

2016-01-01

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the

Research on teaching astronomy in the planetarium

CERN Document Server

Slater, Timothy F

2017-01-01

From a noted specialist in astronomy education and outreach, this Brief provides an overview of the most influential discipline-based science education research literature now guiding contemporary astronomy teaching. In recent years, systematic studies of effective and efficient teaching strategies have provided a solid foundation for enhancing college-level students’ learning in astronomy. Teaching astronomy and planetary science at the college-level was once best characterized as professor-centered, information-download lectures. Today, astronomy faculty are striving to drastically improve the learning environment by using innovative teaching approaches.  Uniquely, the authors have organized this book around strands of commonly employed astronomy teaching strategies to help readers, professors, and scholars quickly access the most relevant work while, simultaneously, avoiding the highly specialized, technical vocabulary of constructivist educational pedagogies unfamiliar to most astronomy professors. F...

Teaching and Learning Astronomy

Science.gov (United States)

Pasachoff, Jay; Percy, John

2009-07-01

Preface; Part I. Astronomy in the Curriculum Around the World: Preface; 1. Why astronomy is useful and should be included in the school curriculum John R. Percy; 2. Astronomy and mathematics education Rosa M. Ros; 3. Astronomy in the curriculum around the world; 4. Engaging gifted science students through astronomy Robert Hollow; 5. Poster highlights: astronomy in the curriculum around the world; Part II. Astronomy Education Research: Preface; 6. Astronomy education research down under John M. Broadfoot and Ian S. Ginns; 7. A contemporary review of K-16 astronomy education research Janelle M. Bailey and Timothy F. Slater; 8. Implementing astronomy education research Leonarda Fucili; 9. The Astronomy Education Review: report on a new journal Sidney C. Wolff and Andrew Fraknoi; 10. Poster highlights: astronomy education research; Part III. Educating Students: Preface; 11. Textbooks for K-12 astronomy Jay M. Pasachoff; 12. Distance/internet astronomy education David H. McKinnon; 13. Educating students with robotic telescopes - open discussion; 14. Poster highlights - educating students; Part IV. Educating teachers: Preface; 15. Pre-service astronomy education of teachers Mary Kay Hemenway; 16. In-service education of teachers Michèle Gerbaldi; 17. Poster highlights: educating teachers; Part V. Astronomy and Pseudoscience: Preface; 18. Astronomy, pseudoscience and rational thinking Jayant V. Narlikar; 19. Astronomical pseudosciences in North America John R. Percy and Jay M. Pasachoff; Part VI. Astronomy and Culture: Preface; 20. Teaching astronomy in other cultures: archeoastronomy Julieta Fierro; 21. Poster highlights: astronomy and culture; Part VII. Astronomy in Developing Countries: Preface; 22. Astronomy Curriculum for developing countries Case Rijsdijk; 23. Science education resources for the developing countries James C. White II; Part VIII. Public Outreach in Astronomy: Preface; 24. What makes informal education programs successful? Nahide Craig and Isabel

Mitigation of Traffic-Induced Ground Vibration by Inclined Wave Barriers

DEFF Research Database (Denmark)

Andersen, Lars; Augustesen, Anders Hust

2009-01-01

Double sheet pile walls can be used as wave barriers in order to mitigate ground vibrations from railways. The present analysis concerns the efficiency of such barriers, especially with regard to the influence of the barrier inclination and the backfill between the walls. Thus, the screening capa...... of reference following the load. This allows a computation of the steady state response to a harmonically varying point source moving at different speeds typical for a train....

Astronomy's New Messengers: A traveling exhibit to out to a young adult audience

International Nuclear Information System (INIS)

Cavaglia, Marco; Hendry, Martin; Marka, Szabolcs; Reitze, David H; Riles, Keith

2010-01-01

The Laser Interferometer Gravitational-wave Observatory exhibit Astronomy's New Messengers: Listening to the Universe with Gravitational Waves is traveling to colleges, universities, museums and other public institutions throughout the United States. In 2010, an extended version of this exhibit will appear in a New York City venue that is accessible to a large and diverse cross section of the general public. Astronomy's New Messengers primarily communicates with an adolescent and young adult audience, potentially inspiring them into the field of science. Acknowledging that this audience is traditionally a difficult one to attract, the exhibit publicly announces itself in a charismatic fashion to reach its principal goals of broadening the community of people interested in science and encouraging interest in science among young people.

The OPTICON technology roadmap for optical and infrared astronomy

Science.gov (United States)

Cunningham, Colin; Melotte, David; Molster, Frank

2010-07-01

The Key Technology Network (KTN) within the OPTICON programme has been developing a roadmap for the technology needed to meet the challenges of optical and infrared astronomy over the next few years, with particular emphasis on the requirements of Extremely Large Telescopes. The process and methodology so far will be described, along with the most recent roadmap. The roadmap shows the expected progression of ground-based astronomy facilities and the technological developments which will be required to realise these new facilities. The roadmap highlights the key stages in the development of these technologies. In some areas, such as conventional optics, gradual developments in areas such as light-weighting of optics will slowly be adopted into future instruments. In other areas, such as large area IR detectors, more rapid progress can be expected as new processing techniques allow larger and faster arrays. Finally, other areas such as integrated photonics have the potential to revolutionise astronomical instrumentation. Future plans are outlined, in particular our intention to look at longer term development and disruptive technologies.

Accessible Astronomy.

Science.gov (United States)

Glickstein, Neil

1994-01-01

Describes the development of a theme-based, multidisciplinary course. The article partitions into the following sections: (1) Constructing the Course; (2) Putting the Ideas to Work; (3) Connecting Science and Society; and (4) The Arts and Astronomy. (ZWH)

Accretion-induced spin-wandering effects on the neutron star in Scorpius X-1: Implications for continuous gravitational wave searches

Science.gov (United States)

Mukherjee, Arunava; Messenger, Chris; Riles, Keith

2018-02-01

The LIGO's discovery of binary black hole mergers has opened up a new era of transient gravitational wave astronomy. The potential detection of gravitational radiation from another class of astronomical objects, rapidly spinning nonaxisymmetric neutron stars, would constitute a new area of gravitational wave astronomy. Scorpius X-1 (Sco X-1) is one of the most promising sources of continuous gravitational radiation to be detected with present-generation ground-based gravitational wave detectors, such as Advanced LIGO and Advanced Virgo. As the sensitivity of these detectors improve in the coming years, so will power of the search algorithms being used to find gravitational wave signals. Those searches will still require integration over nearly year long observational spans to detect the incredibly weak signals from rotating neutron stars. For low mass X-ray binaries such as Sco X-1 this difficult task is compounded by neutron star "spin wandering" caused by stochastic accretion fluctuations. In this paper, we analyze X-ray data from the R X T E satellite to infer the fluctuating torque on the neutron star in Sco X-1. We then perform a large-scale simulation to quantify the statistical properties of spin-wandering effects on the gravitational wave signal frequency and phase evolution. We find that there are a broad range of expected maximum levels of frequency wandering corresponding to maximum drifts of between 0.3 - 50 μ Hz /sec over a year at 99% confidence. These results can be cast in terms of the maximum allowed length of a coherent signal model neglecting spin-wandering effects as ranging between 5-80 days. This study is designed to guide the development and evaluation of Sco X-1 search algorithms.

Reviews in Modern Astronomy: Vol. 15: JENAM 2001: Astronomy with Large Telescopes from Ground and Space

Science.gov (United States)

Schielicke, Reinhard E.

2002-11-01

This 15th volume in the annual series on recent developments and scientific progress in astronomy and astrophysics contains fourteen invited reviews presented during the Joint European and National Astronomical Meeting JENAM 2001, held in Munich, Germany. Readers also learn about the lecture on macro- and microscopic views of nearby galaxies given by Keiichi Kodaira, Japan, who was awarded the Karl Schwarzschild medal 2001. Further contributions on the topic provide the latest results on the search for extra-solar planets, formation of stars and galaxies, physics of active galactic nuclei, as well as new telescopes and sensor technologies for various wavelengths.

Ground receiving station (GRS) of UMS - receiving and processing the electromagnetic wave data from satellite

International Nuclear Information System (INIS)

Mohammad Syahmi Nordin; Fauziah Abdul Aziz

2007-01-01

The low resolution Automatic Picture Transmission (APT) data from the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites Advanced Very High Resolution Radiometer (AVHRR) is being received and recorded in real-time mode at ground receiving station in School of Science and Technology, Universiti Malaysia Sabah. The system is suitable for the developing and undeveloped countries in south and Southeast Asia and is said to be acceptable for engineering, agricultural, climatological and environmental applications. The system comprises a personal computer attached with a small APT receiver. The data transmission between the ground receiving station and NOAA satellites is using the electromagnetic wave. The relation for receiving and processing the electromagnetic wave in the transmission will be discussed. (Author)

Innovation in Astronomy Education

Science.gov (United States)

Pasachoff, Jay M.; Ros, Rosa M.; Pasachoff, Naomi

2013-01-01

Preface; Part I. General Strategies for Effective Teaching: Introduction; 1. Main objectives of SpS2; 2. Learning astronomy by doing astronomy; 3. Hands-on Universe-Europe; 4. Life on Earth in the atmosphere of the Sun; 5. A model of teaching astronomy to pre-service teachers; 6. How to teach, learn about, and enjoy astronomy; 7. Clickers: a new teaching tool of exceptional promise; 8. Educational opportunities in pro-am collaboration; 9. Teaching history of astronomy to second-year engineering students; 10. Teaching the evolution of stellar and Milky Way concepts through the ages; 11. Educational efforts of the International Astronomical Union; 12. Astronomy in culture; 13. Light pollution: a tool for astronomy education; 14. Astronomy by distance learning; 15. Edible astronomy demonstrations; 16. Amateur astronomers as public outreach partners; 17. Does the Sun rotate around Earth or Earth rotate around the Sun?; 18. Using sounds and sonifications for astronomy outreach; 19. Teaching astronomy and the crisis in science education; 20. Astronomy for all as part of a general education; Poster abstracts; Part II. Connecting Astronomy with the Public: Introduction; 21. A status report from the Division XII working group; 22. Outreach using media; 23. Astronomy podcasting; 24. IAU's communication strategy, hands-on science communication, and the communication of the planet definition discussion; 25. Getting a word in edgeways: the survival of discourse in audiovisual astronomy; 26. Critical evaluation of the new Hall of Astronomy; 27. Revitalizing astronomy teaching through research on student understanding; Poster abstracts; Part III. Effective Use of Instruction and Information Technology: Introduction; 28. ESO's astronomy education program; 29. U.S. student astronomy research and remote observing projects; 30. Global network of autonomous observatories dedicated to student research; 31. Remote telescopes in education: report of an Australian study; 32. Visualizing

New frontiers in ground-based optical astronomy

Science.gov (United States)

Strom, Steve

1991-07-01

Technological advances made in telescope designs during 1980's are outlined, including a segmented primary mirror for a 10-m telescope, new mirror-figuring techniques, and control systems based on computers and electronics. A new detector technology employing CCD's and advances in high-resolution telescopes are considered, along with such areas of research ready for major advances given new observing tools as the origin of large-scale structures in the universe, the creation and evolution of galaxies, and the formation of stars and planetary systems. Attention is focused on circumstellar disks, dust veils, jets, and brown dwarfs.

New frontiers in ground-based optical astronomy

International Nuclear Information System (INIS)

Strom, S.

1991-01-01

Technological advances made in telescope designs during 1980's are outlined, including a segmented primary mirror for a 10-m telescope, new mirror-figuring techniques, and control systems based on computers and electronics. A new detector technology employing CCD's and advances in high-resolution telescopes are considered, along with such areas of research ready for major advances given new observing tools as the origin of large-scale structures in the universe, the creation and evolution of galaxies, and the formation of stars and planetary systems. Attention is focused on circumstellar disks, dust veils, jets, and brown dwarfs

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Home; Journals; Journal of Astrophysics and Astronomy; Volume 28; Issue 1. Issue front cover thumbnail. Volume 28, Issue 1. March 2007, pages 1-66. pp 1-7. Oblique Propagation and Dissipation of Alfv´en Waves in Coronal Holes · A. K. Srivastava B. N. Dwivedi · More Details Abstract Fulltext PDF.

Dark Skies Awareness Programs for the U.S. International Year of Astronomy

Science.gov (United States)

Walker, Constance E.; U. S. IYA Dark Skies Working Group

2009-01-01

The loss of a dark night sky as a natural resource is a growing concern. It impacts not only astronomical research, but also our ecology, health, safety, economics and energy conservation. For this reason, "Dark Skies are a Universal Resource” is one of seven primary themes of the U.S. International Year of Astronomy program in 2009. Its goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved in a variety of dark skies-related programs. To reach this goal, activities have been developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking, Second Life) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Discovery Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize an event in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs, as well as RFI monitoring (e.g., GLOBE at Night and Quiet Skies) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., the Dark Skies Toolkit, Good Neighbor Lighting, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial). To deliver these programs, strategic networks have been established with astronomy clubs (ASP's Night Sky Network's astronomy clubs and the Astronomical League), science and nature centers (Astronomy from the Ground Up and the Association of Science and Technology), educational programs (Project ASTRO and GLOBE) and the International Dark-sky Association. The poster will describe the "know-how” and the means for people to become community advocates in promoting Dark Skies programs as public events at their home institutions. For more information, visit http://astronomy2009

Model track studies on fouled ballast using ground penetrating radar and multichannel analysis of surface wave

Science.gov (United States)

Anbazhagan, P.; Lijun, Su; Buddhima, Indraratna; Cholachat, Rujikiatkamjorn

2011-08-01

Ballast fouling is created by the breakdown of aggregates or outside contamination by coal dust from coal trains, or from soil intrusion beneath rail track. Due to ballast fouling, the conditions of rail track can be deteriorated considerably depending on the type of fouling material and the degree of fouling. So far there is no comprehensive guideline available to identify the critical degree of fouling for different types of fouling materials. This paper presents the identification of degree of fouling and types of fouling using non-destructive testing, namely seismic surface-wave and ground penetrating radar (GPR) survey. To understand this, a model rail track with different degree of fouling has been constructed in Civil engineering laboratory, University of Wollongong, Australia. Shear wave velocity obtained from seismic survey has been employed to identify the degree of fouling and types of fouling material. It is found that shear wave velocity of fouled ballast increases initially, reaches optimum fouling point (OFP), and decreases when the fouling increases. The degree of fouling corresponding after which the shear wave velocity of fouled ballast will be smaller than that of clean ballast is called the critical fouling point (CFP). Ground penetrating radar with four different ground coupled antennas (500 MHz, 800 MHz, 1.6 GHz and 2.3 GHz) was also used to identify the ballast fouling condition. It is found that the 800 MHz ground coupled antenna gives a better signal in assessing the ballast fouling condition. Seismic survey is relatively slow when compared to GPR survey however it gives quantifiable results. In contrast, GPR survey is faster and better in estimating the depth of fouling.

Using the Teach Astronomy Website to Enrich Introductory Astronomy Classes

Science.gov (United States)

Hardegree-Ullman, K. K.; Impey, C. D.; Patikkal, A.; Austin, C. L.

2013-04-01

This year we implemented Teach Astronomy as a free online resource to be used as a teaching tool for non-science major astronomy courses and for a general audience interested in the subject. The comprehensive astronomy content of the website includes: an introductory text book, encyclopedia articles, images, two to three minute topical video clips, podcasts, and news articles. Teach Astronomy utilizes a novel technology to cluster, display, and navigate search results, called a Wikimap. We will present an overview of how Teach Astronomy works and how instructors can use it as an effective teaching tool in the classroom. Additionally, we will gather feedback from science instructors on how to improve the features and functionality of the website, as well as develop new assignment ideas using Teach Astronomy.

Acoustic waves in the atmosphere and ground generated by volcanic activity

International Nuclear Information System (INIS)

Ichihara, Mie; Lyons, John; Oikawa, Jun; Takeo, Minoru

2012-01-01

This paper reports an interesting sequence of harmonic tremor observed in the 2011 eruption of Shinmoe-dake volcano, southern Japan. The main eruptive activity started with ashcloud forming explosive eruptions, followed by lava effusion. Harmonic tremor was transmitted into the ground and observed as seismic waves at the last stage of the effusive eruption. The tremor observed at this stage had unclear and fluctuating harmonic modes. In the atmosphere, on the other hand, many impulsive acoustic waves indicating small surface explosions were observed. When the effusion stopped and the erupted lava began explosive degassing, harmonic tremor started to be transmitted also to the atmosphere and observed as acoustic waves. Then the harmonic modes became clearer and more stable. This sequence of harmonic tremor is interpreted as a process in which volcanic degassing generates an open connection between the volcanic conduit and the atmosphere. In order to test this hypothesis, a laboratory experiment was performed and the essential features were successfully reproduced.

Acoustic waves in the atmosphere and ground generated by volcanic activity

Energy Technology Data Exchange (ETDEWEB)

Ichihara, Mie; Lyons, John; Oikawa, Jun; Takeo, Minoru [Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Instituto Geofisico, Escuela Politecnica Nacional, Ladron de Guevara E11-253, Aptdo 2759, Quito (Ecuador); Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

2012-09-04

This paper reports an interesting sequence of harmonic tremor observed in the 2011 eruption of Shinmoe-dake volcano, southern Japan. The main eruptive activity started with ashcloud forming explosive eruptions, followed by lava effusion. Harmonic tremor was transmitted into the ground and observed as seismic waves at the last stage of the effusive eruption. The tremor observed at this stage had unclear and fluctuating harmonic modes. In the atmosphere, on the other hand, many impulsive acoustic waves indicating small surface explosions were observed. When the effusion stopped and the erupted lava began explosive degassing, harmonic tremor started to be transmitted also to the atmosphere and observed as acoustic waves. Then the harmonic modes became clearer and more stable. This sequence of harmonic tremor is interpreted as a process in which volcanic degassing generates an open connection between the volcanic conduit and the atmosphere. In order to test this hypothesis, a laboratory experiment was performed and the essential features were successfully reproduced.

How Create an Astronomy Outreach Program to Bring Astronomy to Thousands of People at Outdoor Concerts Astronomy Festivals, or Tourist Sites

Science.gov (United States)

Lubowich, Donald

2015-08-01

I describe how to create an astronomy program for thousands of people at outdoor concerts based on my $308,000 NASA-funded Music and Astronomy Under the Stars (MAUS) program (60 events 2009 - 2013), and the Astronomy Festival on the National Mall (AFNM, 10,000 people/yr).MAUS reached 50,000 music lovers at local parks and at the Central Park Jazz, Newport Folk, Ravinia, or Tanglewood Music Festivals with classical, folk, pop/rock, opera, Caribbean, or county-western concerts assisted by astronomy clubs. Yo-Yo-Ma, the Chicago and Boston Symphony Orchestras, Ravi Coltrane, Esperanza Spalding, Phish, Blood Sweat and Tears, Deep Purple, Tony Orlando, and Wilco performed at these events. AFNM was started in 2010 with co-sponsorship by the White House Office of Science and Technology Policy. MAUS and AFMN combine solar, optical, and radio telescope observations; large posters/banners; hands-on activities, imaging with a cell phone mount; citizen science activities; hand-outs; and teacher info packet. Representatives from scientific institutions participated. Tyco Brahe, Johannes Kepler, and Caroline Herschel made guest appearances.MAUS reached underserved groups and attracted large crowds. Young kids participated in this family learning experience-often the first time they looked through a telescope. While < 50% of the participants took part in a science activity in the past year, they found MAUS enjoyable and understandable; learned about astronomy; wanted to learn more; and increased their interest in science (ave. rating 3.6/4). MAUS is effective in promoting science education!Lessons learned: plan early; create partnerships with parks, concert organizers, and astronomy clubs; test equipment; have backup equipment; create professional displays; select the best location to obtain a largest number of participants; use social media/www sites to promote the events; use many telescopes for multiple targets; project a live image or video; select equipment that is easy to

First simultaneous measurements of waves generated at the bow shock in the solar wind, the magnetosphere and on the ground

Science.gov (United States)

Clausen, L. B. N.; Yeoman, T. K.; Fear, R. C.; Behlke, R.; Lucek, E. A.; Engebretson, M. J.

2009-01-01

On 5 September 2002 the Geotail satellite observed the cone angle of the Interplanetary Magnetic Field (IMF) change to values below 30° during a 56 min interval between 18:14 and 19:10 UT. This triggered the generation of upstream waves at the bow shock, 13 RE downstream of the position of Geotail. Upstream generated waves were subsequently observed by Geotail between 18:30 and 18:48 UT, during times the IMF cone angle dropped below values of 10°. At 18:24 UT all four Cluster satellites simultaneously observed a sudden increase in wave power in all three magnetic field components, independent of their position in the dayside magnetosphere. We show that the 10 min delay between the change in IMF direction as observed by Geotail and the increase in wave power observed by Cluster is consistent with the propagation of the IMF change from the Geotail position to the bow shock and the propagation of the generated waves through the bow shock, magnetosheath and magnetosphere towards the position of the Cluster satellites. We go on to show that the wave power recorded by the Cluster satellites in the component containing the poloidal and compressional pulsations was broadband and unstructured; the power in the component containing toroidal oscillations was structured and shows the existence of multi-harmonic Alfvénic continuum waves on field lines. Model predictions of these frequencies fit well with the observations. An increase in wave power associated with the change in IMF direction was also registered by ground based magnetometers which were magnetically conjunct with the Cluster satellites during the event. To the best of our knowledge we present the first simultaneous observations of waves created by backstreaming ions at the bow shock in the solar wind, the dayside magnetosphere and on the ground.

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

Multi-Frequency VLBA Studies of the Parsec-Scale Jets in 3C 66A and 3C 66B ... Multi-Wave Luminosity of High-Synchrotron-Peaked TeV BL Lacs Detected by Fermi LAT ..... This kind of profile has been detected in the polarimetric VLBI observation of many blazar objects, ..... Training in Astronomy for Physics Students.

Evolution of ground-state wave function in CeCoIn5 upon Cd or Sn doping

Science.gov (United States)

Chen, K.; Strigari, F.; Sundermann, M.; Hu, Z.; Fisk, Z.; Bauer, E. D.; Rosa, P. F. S.; Sarrao, J. L.; Thompson, J. D.; Herrero-Martin, J.; Pellegrin, E.; Betto, D.; Kummer, K.; Tanaka, A.; Wirth, S.; Severing, A.

2018-01-01

We present linear polarization-dependent soft-x-ray absorption spectroscopy data at the Ce M4 ,5 edges of Cd- and Sn-doped CeCoIn5. The 4 f ground-state wave functions have been determined for their superconducting, antiferromagnetic, and paramagnetic ground states. The absence of changes in the wave functions in CeCo (In1-xCdx) 5 suggests that the 4 f -conduction-electron (c f ) hybridization is not affected by global Cd doping, thus supporting the interpretation of magnetic droplets nucleating long-range magnetic order. This is contrasted by changes in the wave function due to Sn substitution. Increasing Sn in CeCo (In1-ySny) 5 compresses the 4 f orbitals into the tetragonal plane of these materials, suggesting enhanced c f hybridization with the in-plane In(1) atoms and a homogeneous altering of the electronic structure. As these experiments show, the 4 f wave functions are a very sensitive probe of small changes in the hybridization of 4 f and conduction electrons, even conveying information about direction dependencies.

Astronomy Communication

Science.gov (United States)

Heck, A.; Madsen, C.

2003-07-01

Astronomers communicate all the time, with colleagues of course, but also with managers and administrators, with decision makers and takers, with social representatives, with the news media, and with the society at large. Education is naturally part of the process. Astronomy communication must take into account several specificities: the astronomy community is rather compact and well organized world-wide; astronomy has penetrated the general public remarkably well with an extensive network of associations and organizations of aficionados all over the world. Also, as a result of the huge amount of data accumulated and by necessity for their extensive international collaborations, astronomers have pioneered the development of distributed resources, electronic communications and networks coupled to advanced methodologies and technologies, often much before they become of common world-wide usage. This book is filling up a gap in the astronomy-related literature by providing a set of chapters not only of direct interest to astronomy communication, but also well beyond it. The experts contributing to this book have done their best to write in a way understandable to readers not necessarily hyperspecialized in astronomy nor in communication techniques while providing specific detailed information, as well as plenty of pointers and bibliographic elements. This book will be very useful for researchers, teachers, editors, publishers, librarians, computer scientists, sociologists of science, research planners and strategists, project managers, public-relations officers, plus those in charge of astronomy-related organizations, as well as for students aiming at a career in astronomy or related space science. Link: http://www.wkap.nl/prod/b/1-4020-1345-0

African Cultural Astronomy

CERN Document Server

Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa

2008-01-01

Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...

Développement et exploitation d'un simulateur électro-optique pour le futur détecteur spatial à ondes gravitationnelles eLISA

OpenAIRE

Gruning , Pierre

2015-01-01

Gravitational waves will offer a new window to the universe. Their detection by ground based detectors should arrive soon and the future space based interferometer eLISA will allow to do gravitational wave astronomy in order to get unique informations on their sources wether black holes, neutron stars, the Big Bang etc. The effect of a gravitational wave is an extremely weak variation of distance, it will require a very performant detector. That’s why eLISA should reach picometer precision wi...

Astronomy and Politics

Science.gov (United States)

Steele, John M.

The relationship between astronomy and politics is a complex but important part of understanding the practice of astronomy throughout history. This chapter explores some of the ways that astronomy, astrology, and politics have interacted, placing particular focus on the way that astronomy and astrology have been used for political purposes by both people in power and people who wish to influence a ruler's policy. Also discussed are the effects that politics has had on the development of astronomy and, in particular, upon the recording and preservation of astronomical knowledge.

ASTRONET: Strategic Planning for European Astronomy 2005-2025

Science.gov (United States)

Andersen, Johannes; Mourard, Denis

2015-08-01

European astronomy, with ESO and ESA, is supported by a wide variety of independent national agencies or similar bodies, which jointly provide ~98% of the total funding (with ~2% EU grants). In 2005 these agencies concluded that common strategic planning would be a more cost-effective approach, so they founded a consortium, ASTRONET (http://www.astronet-eu.org/), to prototype such an effort for all of Europe, with EU support. A bottom-up process resulted in a Science Vision (2007) and Infrastructure Roadmap (2008) for European astronomy, with recent updates (2014).These ASTRONET reports cover all branches of astronomy; infrastructures at all electromagnetic wavelengths as well as particles etc., on the ground and in space; laboratory work, software and archiving; and training, recruitment and public outreach. In short, they are agreed blueprints for what Europe plans to accomplish in the next 1-2 decades.Subsequently, a systematic and sustained pragmatic effort has been made to implement the strategy laid out in the Roadmap, including a common European participation in projects and facilities of global dimensions. Decisions on the organisation and construction of several major research facilities have been taken as foreseen (E-ELT, SKA, CTA,…), and they are on track for completion around 2025. The task for global astronomy is now to optimise the overall scientific returns and cost-effectiveness of these investments across wavelength domains, scientific disciplines, and political and financial borders. Accordingly, ASTRONET is currently transforming itself into a permanent, self-sustaining activity reaching out to the world.The ideal of a fully integrated global astronomy may not be reached until ~2050, but no science is better suited than astronomy to set such an example: One Universe surrounds us all, and one Earth is our platform. The IAU General Assembly is a springboard towards this goal.

Useful variational principle for the scattering length for the target ground-state wave function imprecisely known

International Nuclear Information System (INIS)

Blau, R.; Rosenberg, L.; Spruch, L.

1977-01-01

A minimum principle for the calculation of the scattering length, applicable when the ground-state wave function of the target system is known precisely, has been available for some time. When, as is almost always the case, the target wave function is imprecisely known, a minimum principle is available but the simple minimum principle noted above is not applicable. Further, as recent calculations show, numerical instabilities usually arise which severely limit the utility of even an ordinary variational approach. The difficulty, which can be traced to the appearance of singularities in the variational construction, is here removed through the introduction of a minimum principle, not for the true scattering length, but for one associated with a closely connected problem. This guarantees that no instability difficulties can arise as the trial scattering wave function and the trial target wave function are improved. The calculations are little different from those required when the target ground-state wave function is known, and, in fact, the original version of the minimum principle is recovered as the trial target wave function becomes exact. A careful discussion is given of the types of problems to which the method can be applied. In particular, the effects of the Pauli principle, and the existence of a finite number of composite bound states, can be accounted for

The RFI situation for a space-based low-frequency radio astronomy instrument

NARCIS (Netherlands)

Bentum, Marinus Jan; Boonstra, A.J.

2016-01-01

Space based ultra-long wavelength radio astronomy has recently gained a lot of interest. Techniques to open the virtually unexplored frequency band below 30 MHz are becoming within reach at this moment. Due to the ionosphere and the radio interference (RFI) on Earth exploring this frequency band

How, precisely, can astronomy be of benefit to anyone?

NARCIS (Netherlands)

Jones, Bernard J. T.; VallsGabaud, D; Boksenberg, A

Astronomy as an observational science is technology driven both from the point of view of data, acquisition and of data processing and visualisation. Astronomy exploits a very wide base of technologies which are developed, enhanced and extended by users. Consequently, astronomy can return new and

Localization of binary neutron star mergers with second and third generation gravitational-wave detectors

Science.gov (United States)

Mills, Cameron; Tiwari, Vaibhav; Fairhurst, Stephen

2018-05-01

The observation of gravitational wave signals from binary black hole and binary neutron star mergers has established the field of gravitational wave astronomy. It is expected that future networks of gravitational wave detectors will possess great potential in probing various aspects of astronomy. An important consideration for successive improvement of current detectors or establishment on new sites is knowledge of the minimum number of detectors required to perform precision astronomy. We attempt to answer this question by assessing the ability of future detector networks to detect and localize binary neutron stars mergers on the sky. Good localization ability is crucial for many of the scientific goals of gravitational wave astronomy, such as electromagnetic follow-up, measuring the properties of compact binaries throughout cosmic history, and cosmology. We find that although two detectors at improved sensitivity are sufficient to get a substantial increase in the number of observed signals, at least three detectors of comparable sensitivity are required to localize majority of the signals, typically to within around 10 deg2 —adequate for follow-up with most wide field of view optical telescopes.

Astronomy across cultures the history of non-Western astronomy

CERN Document Server

Xiaochun, Sun

2000-01-01

Astronomy Across Cultures: A History of Non-Western Astronomy consists of essays dealing with the astronomical knowledge and beliefs of cultures outside the United States and Europe. In addition to articles surveying Islamic, Chinese, Native American, Aboriginal Australian, Polynesian, Egyptian and Tibetan astronomy, among others, the book includes essays on Sky Tales and Why We Tell Them and Astronomy and Prehistory, and Astronomy and Astrology. The essays address the connections between science and culture and relate astronomical practices to the cultures which produced them. Each essay is well illustrated and contains an extensive bibliography. Because the geographic range is global, the book fills a gap in both the history of science and in cultural studies. It should find a place on the bookshelves of advanced undergraduate students, graduate students, and scholars, as well as in libraries serving those groups.

Teach Astronomy: An Online Resource for Introductory Astronomy Courses and Informal Learners

Science.gov (United States)

Austin, Carmen; Impey, C. D.; Hardegree-Ullman, K.; Patikkal, A.; Ganesan, N.

2013-01-01

Teach Astronomy (www.teachastronomy.com) is a new, free online resource—a teaching tool for non-science major astronomy courses and a reference guide for lifelong learners interested in the subject. Digital content available includes: a comprehensive introductory astronomy textbook by Chris Impey, Wikipedia astronomy articles, images from Astronomy Picture of the Day archives and AstroPix database, two to three minute topical video clips by Chris Impey, podcasts from 365 Days of Astronomy archives, and an RSS feed of astronomy news from Science Daily. Teach Astronomy features an original technology called the Wikimap to cluster, display, and navigate site search results. Motivation behind the development of Teach Astronomy includes steep increases in textbook prices, the rapid adoption by students and the public of digital resources, and the modern capabilities of digital technology. Recent additions to Teach Astronomy include: AstroPix images—from some of the most advanced observatories and complete with metadata, mobile device functionality, links to WikiSky where users can see the location of astronomical objects in the sky, and end of chapter textbook review questions. Next in line for development are assignments for classroom use. We present suggestions for utilizing the rich content and features of the web site.

Philippine Astronomy Convention 2009 Abstract: Program Offerings in Astronomy in the Philippines

Science.gov (United States)

Torres, J. R. F.

2009-03-01

The formal academic programs in Astronomy of the Rizal Technological University are the first such programs in the Philippines. The Master of Science in Astronomy program is envisioned to provide the student with a wide range of knowledge in many areas of Astronomy, leaning towards the descriptive aspects of knowledge. The student will choose the field or research most suitable to his or her interests. Three of these researches done while enrolled in the program, and even researches completed before the student actually enrolled in the program, may be considered as his or her thesis. The program suits professionals in all persuasions who wish to study Astronomy either for professional advancement or plainly for the love of the science or for intellectual satisfaction. Non-science majors can enroll. In 2008, the RTU Graduate School decided to ladderize the MS program and the Graduate Diploma in Astronomy was designed. This program is suited for science educators, astronomy lecturers and entrepreneurs, members of astronomical societies, and plain astronomy enthusiasts who like to gain in-depth knowledge in the most important aspects of astronomy. A bachelor's degree in any field is required. The program can be finished in two semesters and one summer. If the student opts to continue in the MS in Astronomy program, all the courses he or she has earned in the Diploma will be credited. The Bachelor of Science in Astronomy Technology is an intensive baccalaureate degree program designed to prepare students to become future research scientists and technologists in the field of Astronomy. The BS in Astronomy Technology is a cross-fertilized program, integrating interrelated sciences, such as engineering, geology, remote sensing, physics, atmospheric and environmental science, biology and biochemistry, and even philosophy and entrepreneurship into the study. Thus, the B.S. in Astronomy Technology program gives the student excellent job opportunities in many fields.

Superconducting Kinetic Inductance Detectors for astronomy and particle physics

International Nuclear Information System (INIS)

Calvo, M.; Goupy, J.; D'Addabbo, A.; Benoit, A.; Bourrion, O.; Catalano, A.; Monfardini, A.

2016-01-01

Kinetic Inductance Detectors (KID) represent a novel detector technology based on superconducting resonators. Since their first demonstration in 2003, they have been rapidly developed and are today a strong candidate for present and future experiments in the different bands of the electromagnetic spectrum. This has been possible thanks to the unique features of such devices: in particular, they couple a very high sensitivity to their intrinsic suitability for frequency domain multiplexed readout, making the fabrication of large arrays of ultrasensitive detectors possible. There are many fields of application that can profit of such detectors. Here, we will briefly review the principle of operation of a KID, and give two sample applications, to mm-wave astronomy and to particle physics.

Superconducting Kinetic Inductance Detectors for astronomy and particle physics

Energy Technology Data Exchange (ETDEWEB)

Calvo, M., E-mail: martino.calvo@neel.cnrs.fr [Institute Néel, CNRS, Grenoble (France); Goupy, J.; D' Addabbo, A.; Benoit, A. [Institute Néel, CNRS, Grenoble (France); Bourrion, O. [Laboratoire de Physique Subatomique et Cosmologie, CNRS, Grenoble (France); Catalano, A. [Institute Néel, CNRS, Grenoble (France); Laboratoire de Physique Subatomique et Cosmologie, CNRS, Grenoble (France); Monfardini, A. [Institute Néel, CNRS, Grenoble (France)

2016-07-11

Kinetic Inductance Detectors (KID) represent a novel detector technology based on superconducting resonators. Since their first demonstration in 2003, they have been rapidly developed and are today a strong candidate for present and future experiments in the different bands of the electromagnetic spectrum. This has been possible thanks to the unique features of such devices: in particular, they couple a very high sensitivity to their intrinsic suitability for frequency domain multiplexed readout, making the fabrication of large arrays of ultrasensitive detectors possible. There are many fields of application that can profit of such detectors. Here, we will briefly review the principle of operation of a KID, and give two sample applications, to mm-wave astronomy and to particle physics.

Distribution of base rock depth estimated from Rayleigh wave measurement by forced vibration tests

International Nuclear Information System (INIS)

Hiroshi Hibino; Toshiro Maeda; Chiaki Yoshimura; Yasuo Uchiyama

2005-01-01

This paper shows an application of Rayleigh wave methods to a real site, which was performed to determine spatial distribution of base rock depth from the ground surface. At a certain site in Sagami Plain in Japan, the base rock depth from surface is assumed to be distributed up to 10 m according to boring investigation. Possible accuracy of the base rock depth distribution has been needed for the pile design and construction. In order to measure Rayleigh wave phase velocity, forced vibration tests were conducted with a 500 N vertical shaker and linear arrays of three vertical sensors situated at several points in two zones around the edges of the site. Then, inversion analysis was carried out for soil profile by genetic algorithm, simulating measured Rayleigh wave phase velocity with the computed counterpart. Distribution of the base rock depth inverted from the analysis was consistent with the roughly estimated inclination of the base rock obtained from the boring tests, that is, the base rock is shallow around edge of the site and gradually inclines towards the center of the site. By the inversion analysis, the depth of base rock was determined as from 5 m to 6 m in the edge of the site, 10 m in the center of the site. The determined distribution of the base rock depth by this method showed good agreement on most of the points where boring investigation were performed. As a result, it was confirmed that the forced vibration tests on the ground by Rayleigh wave methods can be useful as the practical technique for estimating surface soil profiles to a depth of up to 10 m. (authors)

Future Professional Communication in Astronomy II

Science.gov (United States)

Accomazzi, Alberto

The present volume gathers together the talks presented at the second colloquium on the Future Professional Communication in Astronomy (FPCAII), held at the Harvard-Smithsonian Center for Astrophysics (Cambridge, MA) on 13-14 April 2010. This meeting provided a forum for editors, publishers, scientists, librarians and officers of learned societies to discuss the future of the field. The program included talks from leading researchers and practitioners and drew a crowd of approximately 50 attendees from 10 countries. These proceedings contain contributions from invited and contributed talks from leaders in the field, touching on a number of topics. Among them: The role of disciplinary repositories such as ADS and arXiv in astronomy and the physical sciences; Current status and future of Open Access Publishing models and their impact on astronomy and astrophysics publishing; Emerging trends in scientific article publishing: semantic annotations, multimedia content, links to data products hosted by astrophysics archives; Novel approaches to the evaluation of facilities and projects based on bibliometric indicators; Impact of Government mandates, Privacy laws, and Intellectual Property Rights on the evolving digital publishing environment in astronomy; Communicating astronomy to the public: the experience of the International Year of Astronomy 2009.

Introducing Astronomy Related Research into Non-Astronomy Courses

Science.gov (United States)

Walker, Douglas

The concern over the insufficient number of students choosing to enter the science and engineering fields has been discussed and documented for years. While historically addressed at the national level, many states are now recognizing that the lack of a highly-skilled technical workforce within their states' borders has a significant effect on their economic health. Astronomy, as a science field, is no exception. Articles appear periodically in the most popular astronomy magazines asking the question, "Where are the young astronomers?" Astronomy courses at the community college level are normally restricted to introductory astronomy I and II level classes that introduce the student to the basics of the night sky and astronomy. The vast majority of these courses is geared toward the non-science major and is considered by many students to be easy and watered down courses in comparison to typical physics and related science courses. A majority of students who enroll in these classes are not considering majors in science or astronomy since they believe that science is "boring and won't produce any type of career for them." Is there any way to attract students? This paper discusses an approach being undertaken at the Estrella Mountain Community College to introduce students in selected mathematics courses to aspects of astronomy related research to demonstrate that science is anything but boring. Basic statistical techniques and understanding of geometry are applied to a large virgin data set containing the magnitudes and phase characteristics of sets of variable stars. The students' work consisted of developing and presenting a project that explored analyzing selected aspects of the variable star data set. The description of the data set, the approach the students took for research projects, and results from a survey conducted at semester's end to determine if student's interest and appreciation of astronomy was affected are presented. Using the data set provided, the

Earthquake early warning using P-waves that appear after initial S-waves

Science.gov (United States)

Kodera, Y.

2017-12-01

As measures for underprediction for large earthquakes with finite faults and overprediction for multiple simultaneous earthquakes, Hoshiba (2013), Hoshiba and Aoki (2015), and Kodera et al. (2016) proposed earthquake early warning (EEW) methods that directly predict ground motion by computing the wave propagation of observed ground motion. These methods are expected to predict ground motion with a high accuracy even for complicated scenarios because these methods do not need source parameter estimation. On the other hand, there is room for improvement in their rapidity because they predict strong motion prediction mainly based on the observation of S-waves and do not explicitly use P-wave information available before the S-waves. In this research, we propose a real-time P-wave detector to incorporate P-wave information into these wavefield-estimation approaches. P-waves within a few seconds from the P-onsets are commonly used in many existing EEW methods. In addition, we focus on P-waves that may appear in the later part of seismic waves. Kurahashi and Irikura (2013) mentioned that P-waves radiated from strong motion generation areas (SMGAs) were recognizable after S-waves of the initial rupture point in the 2011 off the Pacific coast of Tohoku earthquake (Mw 9.0) (the Tohoku-oki earthquake). Detecting these P-waves would enhance the rapidity of prediction for the peak ground motion generated by SMGAs. We constructed a real-time P-wave detector that uses a polarity analysis. Using acceleration records in boreholes of KiK-net (band-pass filtered around 0.5-10 Hz with site amplification correction), the P-wave detector performed the principal component analysis with a sliding window of 4 s and calculated P-filter values (e.g. Ross and Ben-Zion, 2014). The application to the Tohoku-oki earthquake (Mw 9.0) showed that (1) peaks of P-filter that corresponded to SMGAs appeared in several stations located near SMGAs and (2) real-time seismic intensities (Kunugi et al

Astronomy in Mozambique

Science.gov (United States)

Ribeiro, Valério A. R. M.; Paulo, Cláudio M.

2015-03-01

We present the state of Astronomy in Mozambique and how it has evolved since 2009 following the International Year of Astronomy. Activities have been lead by staff at University Eduardo Mondlane and several outreach activities have also flourished. In 2010 the University introduced its first astronomy module, Introduction to Astronomy and Astrophysics, for the second year students in the Department of Physics. The course has now produced the first students who will be graduating in late 2012 with some astronomy content. Some of these students will now be looking for further studies and those who have been keen in astronomy have been recommended to pursue this as a career. At the university level we have also discussed on the possibility to introduce a whole astronomy course by 2016 which falls well within the HCD that the university is now investing in. With the announcement that the SKA will be split between South Africa with its partner countries (including Mozambique), and Australia we have been working closely with the Ministry of Science and Technology to make astronomy a priority on its agenda. In this respect, an old telecommunications antenna is being converted by the South Africa SKA Project Office, and donated to Mozambique for educational purposes. It will be situated in Maluana, Mozambique.

Gravitational Waves and Neutrinos

OpenAIRE

Sturani, Riccardo

2018-01-01

We give an overview about the recent detection of gravitational waves by the Advanced LIGO first and second observing runs and by Advanced Virgo, with emphasis on the prospects for multi-messenger astronomy involving neutrinos detections.

Music and Astronomy Under the Stars

Science.gov (United States)

Lubowich, D.

2008-11-01

Bring telescope to where the people are! Music and Astronomy Under the Stars is a public astronomy outreach program at community parks during and after free summer music concerts and outdoor movie nights. This project also includes daytime activities because there are some afternoon concerts and daylight children's concerts, and observations using remotely operated telescopes in cloudy weather. While there have been many astronomy outreach activities and telescope observations at city sidewalks and parks, this program targets a completely different audience---music lovers who are attending free summer concerts held in community parks. The music lovers who may never have visited a science museum, planetarium, or star party will be exposed to telescope observations and astronomy information with no additional travel costs. This program will permit the entire community to participate in telescope observations and view astronomical video information to enhance the public appreciation of astronomy. This program will also reach underrepresented and underserved groups (women, minorities, older adults). The population base for the initial target audience (Nassau and Suffolk Counties, New York) is 2,500,000. My partners are the Amateur Observers' Society of New York (AOS) and the Towns of Oyster Bay, Hempstead, North Hempstead, and Huntington. Music and Astronomy Under the Stars is program that should continue beyond the International Year of Astronomy 2009 (IYA2009) and can be expanded into a national program.

RECENT DEVELOPMENTS IN ULTRA-HIGH ENERGY NEUTRINO ASTRONOMY

Directory of Open Access Journals (Sweden)

Peter K. F. Grieder

2013-12-01

Full Text Available We outline the current situation in ultrahigh energy (UHE cosmic ray physics, pointing out the remaining problems, in particular the puzzle concerning the origin of the primary radiation and the role of neutrino astronomy for locating the sources. Various methods for the detection of UHE neutrinos are briefly described and their merits compared. We give an account of the achievements of the existing optical Cherenkov neutrino telescopes, outline the possibility of using air fluorescence and particle properties of air showers to identify neutrino induced events, and discuss various pioneering experiments employing radio and acoustic detection of extremely energetic neutrinos. The next generation of space, ground and sea based neutrino telescopes now under construction or in the planning phase are listed.

Five-day planetary waves in the middle atmosphere from Odin satellite data and ground-based instruments in Northern Hemisphere summer 2003, 2004, 2005 and 2007

Directory of Open Access Journals (Sweden)

A. Belova

2008-11-01

Full Text Available A number of studies have shown that 5-day planetary waves modulate noctilucent clouds and the closely related Polar Mesosphere Summer Echoes (PMSE at the summer mesopause. Summer stratospheric winds should inhibit wave propagation through the stratosphere and, although some numerical models (Geisler and Dickinson, 1976 do show a possibility for upward wave propagation, it has also been suggested that the upward propagation may in practice be confined to the winter hemisphere with horizontal propagation of the wave from the winter to the summer hemisphere at mesosphere heights causing the effects observed at the summer mesopause. It has further been proposed (Garcia et al., 2005 that 5-day planetary waves observed in the summer mesosphere could be excited in-situ by baroclinic instability in the upper mesosphere. In this study, we first extract and analyze 5-day planetary wave characteristics on a global scale in the middle atmosphere (up to 54 km in temperature, and up to 68 km in ozone concentration using measurements by the Odin satellite for selected days during northern hemisphere summer from 2003, 2004, 2005 and 2007. Second, we show that 5-day temperature fluctuations consistent with westward-traveling 5-day waves are present at the summer mesopause, using local ground-based meteor-radar observations. Finally we examine whether any of three possible sources of the detected temperature fluctuations at the summer mesopause can be excluded: upward propagation from the stratosphere in the summer-hemisphere, horizontal propagation from the winter-hemisphere or in-situ excitation as a result of the baroclinic instability. We find that in one case, far from solstice, the baroclinic instability is unlikely to be involved. In one further case, close to solstice, upward propagation in the same hemisphere seems to be ruled out. In all other cases, all or any of the three proposed mechanisms are consistent with the observations.

Observing Tsunamis in the Ionosphere Using Ground Based GPS Measurements

Science.gov (United States)

Galvan, D. A.; Komjathy, A.; Song, Y. Tony; Stephens, P.; Hickey, M. P.; Foster, J.

2011-01-01

Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following recent seismic events, including the Tohoku tsunami of March 11, 2011. We observe fluctuations correlated in time, space, and wave properties with this tsunami in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the Tohoku tsunami near the epicenter, at Hawaii, and near the west coast of North America. Disturbance magnitudes are 1-10% of the background TEC value. Observations near the epicenter are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement. The potential exists to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for future early warning systems.

Teach Astronomy: An Online Textbook for Introductory Astronomy Courses and Resources for Informal Learners

Science.gov (United States)

Hardegree-Ullman, Kevin; Impey, C. D.; Patikkal, A.

2012-05-01

This year we implemented Teach Astronomy (www.teachastronomy.com) as a free online resource to be used as a teaching tool for non-science major astronomy courses and for a general audience interested in the subject. The comprehensive content includes: an introductory astronomy text book by Chris Impey, astronomy articles on Wikipedia, images from the Astronomy Picture of the Day, two to three minute topical video clips by Chris Impey, podcasts from 365 Days of Astronomy, and astronomy news from Science Daily. Teach Astronomy utilizes a novel technology to cluster, display, and navigate search results, called a Wikimap. Steep increases in textbook prices and the unique capabilities of emerging web technology motivated the development of this free online resource. Recent additions to Teach Astronomy include: images and diagrams for the textbook articles, mobile device implementation, and suggested homework assignments for instructors that utilize recent discoveries in astronomy. We present an overview of how Teach Astronomy has been implemented for use in the classroom and informal settings, and suggestions for utilizing the rich content and features of the web site.

Monitoring geospace disturbances through coordinated space-borne and ground-based magnetometer observations

Science.gov (United States)

Balasis, Georgios

2014-05-01

Recently automated methods of deriving the characteristics of ultra low frequency (ULF) waves in the magnetosphere have been developed (Balasis et al., 2012, 2013), which can be effectively applied to the huge datasets from the new ESA Swarm mission, in order to retrieve, on an operational basis, new information about the near-Earth electromagnetic environment. Processing Swarm measurements with these methods will help to elucidate the processes influencing the generation and propagation of ULF waves, which in turn play a crucial role in magnetospheric dynamics. Moreover, a useful platform based on a combination of wavelet transforms and artificial neural networks has been developed to monitor the wave evolution from the outer boundaries of Earth's magnetosphere through the topside ionosphere down to the surface. Data from a Low Earth Orbit (LEO) satellite (CHAMP) and two magnetospheric missions (Cluster and Geotail) along with three ground-based magnetic networks (CARISMA, GIMA and IMAGE), during the Halloween 2003 magnetic superstorm when the Cluster and CHAMP spacecraft were in good local time (LT) conjunction, are used to demonstrate the potential of the analysis technique in studying wave evolution in detail.

2011 Astronomy Day at McDonald Observatory

Science.gov (United States)

Preston, Sandra; Hemeway, M.; Wetzel, M.

2012-01-01

Our philosophy is that everyday is Astronomy Day because the McDonald Observatory's Frank N. Bash Visitors Center is open 362 days a year. So, how did we create a special celebration for the "Astronomy Day” declared by the Astronomical League? During September 26-29 we conducted 20 videoconferences and served 12,559 students with "Astronomy Day” programming. Connect2Texas provides bridging for a network of Texas-based museums and cultural, historical, and scientific organizations that offer educational content to schools throughout the state via videoconferencing. Connect2Texas connected McDonald Observatory to 334 schools; most of these schools were in Texas, but schools in a dozen other states also participated. While most schools had a "view-only" connection, at least 20 of the schools had interactive connections, whereby the students could ask questions of the presenter. Connect2Texas also collects evaluation information from the participating schools that we will use to produce a report for our funders and make modifications to future programs as need be. The videoconferences were offered free of charge. The theme for the 2011 Astronomy Day program was the Year of the Solar System, which aligns with NASA's theme for 2011 and 2012. By aligning with this NASA theme, we could leverage NASA artwork and materials to both advertise and enrich the learning experience. Videoconference materials also included pre- and post-videoconference assessment sheets, an inquiry based activity, and pre- and post-videoconference activities, all of which were made available online. One of the lessons learned from past Astronomy Day videoconferences is that the days the Astronomical League declares as "Astronomy Day” are not always good days for Texas schools to participate. So, we choose an Astronomy Day that meets the needs of Texas schools and our schedule - so any day can be Astronomy Day. 2011 Astronomy Day was made possible by The Meyer-Levy Charitable Trust.

Armenian Cultural Astronomy

Science.gov (United States)

Farmanyan, S. V.; Mickaelian, A. M.

2015-07-01

Cultural Astronomy is the reflection of sky events in various fields of nations' culture. In foreign literature this field is also called "Astronomy in Culture" or "Astronomy and Culture". Cultural astronomy is the set of interdisciplinary fields studying the astronomical systems of current or ancient societies and cultures. It is manifested in Religion, Mythology, Folklore, Poetry, Art, Linguistics and other fields. In recent years, considerable attention has been paid to this sphere, particularly international organizations were established, conferences are held and journals are published. Armenia is also rich in cultural astronomy. The present paper focuses on Armenian archaeoastronomy and cultural astronomy, including many creations related to astronomical knowledge; calendars, rock art, mythology, etc. On the other hand, this subject is rather poorly developed in Armenia; there are only individual studies on various related issues (especially many studies related to Anania Shirakatsi) but not coordinated actions to manage this important field of investigation.

Estimation of High-Frequency Earth-Space Radio Wave Signals via Ground-Based Polarimetric Radar Observations

Science.gov (United States)

Bolen, Steve; Chandrasekar, V.

2002-01-01

Expanding human presence in space, and enabling the commercialization of this frontier, is part of the strategic goals for NASA's Human Exploration and Development of Space (HEDS) enterprise. Future near-Earth and planetary missions will support the use of high-frequency Earth-space communication systems. Additionally, increased commercial demand on low-frequency Earth-space links in the S- and C-band spectra have led to increased interest in the use of higher frequencies in regions like Ku and Ka-band. Attenuation of high-frequency signals, due to a precipitating medium, can be quite severe and can cause considerable disruptions in a communications link that traverses such a medium. Previously, ground radar measurements were made along the Earth-space path and compared to satellite beacon data that was transmitted to a ground station. In this paper, quantitative estimation of the attenuation along the propagation path is made via inter-comparisons of radar data taken from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and ground-based polarimetric radar observations. Theoretical relationships between the expected specific attenuation (k) of spaceborne measurements with ground-based measurements of reflectivity (Zh) and differential propagation phase shift (Kdp) are developed for various hydrometeors that could be present along the propagation path, which are used to estimate the two-way path-integrated attenuation (PIA) on the PR return echo. Resolution volume matching and alignment of the radar systems is performed, and a direct comparison of PR return echo with ground radar attenuation estimates is made directly on a beam-by-beam basis. The technique is validated using data collected from the TExas and Florida UNderflights (TEFLUN-B) experiment and the TRMM large Biosphere-Atmosphere experiment in Amazonia (LBA) campaign. Attenuation estimation derived from this method can be used for strategiC planning of communication systems for

Towards gravitational-wave astronomy of core-collapse supernova explosion

International Nuclear Information System (INIS)

Kotake, Kei

2010-01-01

We study properties of gravitational waves based on the three-dimensional (3D) simulations, which demonstrate the neutrino-driven explosions aided by the standing accretion shock instability (SASI). Pushed by evidence supporting slow rotation prior to core-collapse, we focus on the asphericities in neutrino emissions and matter motions outside the protoneutron star. By performing a ray-tracing calculation in 3D, we estimate accurately the gravitational waveforms from anisotropic neutrino emissions. In contrast to the previous work assuming axisymmetry, we find that the gravitational waveforms vary much more stochastically because the explosion anisotropies depend sensitively on the growth of the SASI which develops chaotically in all directions. Our results show that the gravitational-wave spectrum has its peak near ∼ 100 Hz, reflecting the SASI-induced matter overturns of ∼ O(10) ms. We point out that the detection of such signals, possibly visible to the LIGO-class detectors for a Galactic supernova, could be an important probe into the long-veiled explosion mechanism.

Making Space for Specialized Astronomy Resources

Science.gov (United States)

MacMillan, D.

2007-10-01

With the growth of both free and subscription-based resources, articles on astronomy have never been easier to find. Locating the best and most current materials for any given search, however, now requires multiple tools and strategies dependent on the query. An analysis of the tools currently available shows that while astronomy is well-served by Google Scholar, Scopus and Inspec, its literature is best accessed through specialized resources such as ADS (Astrophysics Data System). While no surprise to astronomers, this has major implications for those of us who teach information literacy skills to astronomy students and work in academic settings where astronomy is just one of many subjects for which our non-specialist colleagues at the reference desk provide assistance. This paper will examine some of the implications of this analysis for library instruction, reference assistance and training, and library webpage development.

The Astronomy Workshop

Science.gov (United States)

Hamilton, D. P.; Asbury, M. L.; Proctor, A.

2001-12-01

The Astronomy Workshop (http://janus.astro.umd.edu) is an interactive online astronomy resource developed, and maintained at the University of Maryland, for use by students, educators and the general public. The Astronomy Workshop has been extensively tested and used successfully at many different levels, including High School and Junior High School science classes, University introductory astronomy courses, and University intermediate and advanced astronomy courses. Some topics currently covered in the Astronomy Workshop are: Animated Orbits of Planets and Moons: The orbits of the nine planets and 91 known planetary satellites are shown in animated, to-scale drawings. The orbiting bodies move at their correct relative speeds about their parent, which is rendered as an attractive, to-scale gif image. Solar System Collisions: This most popular of our applications shows what happens when an asteroid or comet with user-defined size and speed impacts a given planet. The program calculates many effects, including the country impacted (if Earth is the target), energy of the explosion, crater size, magnitude of the planetquake generated. It also displays a relevant image (e.g. terrestrial crater, lunar crater, etc.). Planetary and Satellite Data Calculators: These tools allow the user to easily calculate physical data for all of the planets or satellites simultaneously, making comparison very easy. Orbital Simulations: These tools allow the student to investigate different aspects of the three-body problem of celestial mechanics. Astronomy Workshop Bulletin Board: Get innovative teaching ideas and read about in-class experiences with the Astronomy Workshop. Share your ideas with other educators by posting on the Bulletin Board. Funding for the Astronomy Workshop is provided by the National Science Foundation.

Gravitational-wave research: Current status and future prospects

International Nuclear Information System (INIS)

Thorne, K.S.

1980-01-01

There is a reasonably good change that in the 1980s cosmic gravitational waves will be discovered and will become a powerful tool for astronomy. This prospect has stimulated a three-pronged research effort. First, relativity theorists are developing new mathematical tools for the analysis of gravitational radiation: including (i) methods of analyzing the generation of gravity waves by sources with strong self-gravity and large internal velocities (e.g., collisions of black holes), (ii) methods of computing radiation reaction in sources, and (iii) methods of analyzing how gravitational waves propagate through our lumpy curved-space Universe. Second, astrophysicists are attempting to identify the most promissing sources of gravitational waves, and are using the relativity theorists' mathematical tools to estimate the characteristics of the waves they emit. Third, with the estimated wave characteristics in mind, experimenters are designing and constructing a second generation of gravitational-wave detectors: detectors of three types: Doppler tracking of interplanetary spacecraft, Earth-based laser interferometers, and Earth-based Weber-type resonant bars. This article reviews, in brief, all three prongs of the research effort and gives references to more detailed articles about specialized aspects of gravitational-wave physics

Research-Based Astronomy Workshops for Secondary School Students in Thailand

Science.gov (United States)

Rujopakarn, Wiphu; Kirdkao, Thagoon

We present the results of the Learning Center for Earth Sciences and Astronomy (LESA). Thai-land organizes a series of research-based astronomical workshops for secondary school students in the country during 2006 present. The goal of LESA is to apply the research-based learn-ing approach to complement astronomy education, which has been included in the national curriculum since 2002, and to let students gain first-hand experience in astronomical research. Realization of research-based astronomical education in Thailand has long been held back by the limited availability of astronomical facilities in the country. We therefore developed work-shop modules for students using professional astronomical data generously made available to us through various collaborations and on-line archives. Two major difficulties we have overcame in developing these modules are, first, to seek research topics that are meaningful, inspiring, and can demonstrate the process of astronomical research with minimal background in astrophysics, and second, to find the software capable of processing large amounts of astronomical data, yet easily accessible for students. Our workshop modules centered on the basic research methods in observational astronomy, including astrometry, photometry, and spectroscopy. Data for these analysis modules were obtained through collaboration with various research groups, such as re-mote robotic telescopes access from the Robotic Optical Transient Search Experiment and the Las Cumbres Observatory Global Telescope Network, archival images from the Catalina Sky Survey, archival spectra from the Observatoire de Haute-Provence, and imaging and spectral data from the Sloan Digital Sky Survey. We adapt the raw data such that they can be accessed and analyzed with freely-available astronomical software such as the Iris or SAOImage ds9 and VSpec for imaging and spectral data, respectively. In each of the past five years, we have organized year-round workshops for students

Spectroscopic characterization of extrasolar planets from ground-, space- and airborne-based observatories

Science.gov (United States)

Angerhausen, Daniel

2010-11-01

This thesis deals with techniques and results of observations of exoplanets from several platforms. In this work I present and then attempt solutions to particular issues and problems connected to ground- and space-based approaches to spectroscopic characterization of extrasolar planets. Furthermore, I present the future prospects of the airborne observatory, SOFIA, in this field of astronomy. The first part of this thesis covers results of an exploratory study to use near-infrared integral-field-spectroscopy to observe transiting extrasolar planets. I demonstrate how adaptive-optics assisted integral field spectroscopy compares with other spectroscopic techniques currently applied, foremost being slit spectroscopy. An advanced reduction method using elements of a spectral-differential decorrelation and optimized observation strategies is discussed. This concept was tested with K-Band time series observations of secondary eclipses of HD 209458b and HD 189733b obtained with the SINFONI at the Very Large Telescope (VLT), at spectral resolution of R~3000. In ground-based near infrared (NIR) observations, there is considerable likelihood of confusion between telluric absorption features and spectral features in the targeted object. I describe a detailed method that can cope with such confusion by a forward modelling approach employing Earth transmission models. In space-based transit spectroscopy with Hubble's NICMOS instrument, the main source of systematic noise is the perturbation in the instrument's configuration due to the near Earth orbital motion of the spacecraft. I present an extension to a pre-existing data analysis sequence that has allowed me to extract a NIR transmission spectrum of the hot-Neptune class planet GJ 436b from a data set that was highly corrupted by the above mentioned effects. Satisfyingly, I was able to obtain statistical consistency in spectra (acquired over a broad wavelength grid) over two distinct observing visits by HST. Earlier

On the verge of an astronomy CubeSat revolution

Science.gov (United States)

Shkolnik, Evgenya L.

2018-05-01

CubeSats are small satellites built in standard sizes and form factors, which have been growing in popularity but have thus far been largely ignored within the field of astronomy. When deployed as space-based telescopes, they enable science experiments not possible with existing or planned large space missions, filling several key gaps in astronomical research. Unlike expensive and highly sought after space telescopes such as the Hubble Space Telescope, whose time must be shared among many instruments and science programs, CubeSats can monitor sources for weeks or months at time, and at wavelengths not accessible from the ground such as the ultraviolet, far-infrared and low-frequency radio. Science cases for CubeSats being developed now include a wide variety of astrophysical experiments, including exoplanets, stars, black holes and radio transients. Achieving high-impact astronomical research with CubeSats is becoming increasingly feasible with advances in technologies such as precision pointing, compact sensitive detectors and the miniaturization of propulsion systems. CubeSats may also pair with the large space- and ground-based telescopes to provide complementary data to better explain the physical processes observed.

Astronomers Without Borders: A Global Astronomy Community

Science.gov (United States)

Simmons, M.

2011-10-01

Astronomers Without Borders (AWB) brings together astronomy enthusiasts of all types - amateur astronomers, educators, professionals and "armchair" astronomers for a variety of online and physicalworld programs. The AWB web site provides social networking and a base for online programs that engage people worldwide in astronomy activities that transcend geopolitical and cultural borders. There is universal interest in astronomy, which has been present in all cultures throughout recorded history. Astronomy is also among the most accessible of sciences with the natural laboratory of the sky being available to people worldwide. There are few other interests for which people widely separated geographically can engage in activities involving the same objects. AWB builds on those advantages to bring people together. AWB also provides a platform where projects can reach a global audience. AWB also provides unique opportunities for multidisciplinary collaboration in EPO programs. Several programs including The World at Night, Global Astronomy Month and others will be described along with lessons learned.

Fundamental Astronomy

CERN Document Server

Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan

2007-01-01

Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

Greek astronomy

CERN Document Server

Heath, Sir Thomas L

2011-01-01

Astronomy as a science began with the Ionian philosophers, with whom Greek philosophy and mathematics also began. While the Egyptians and Babylonians had accomplished much of astronomical worth, it remained for the unrivalled speculative genius of the Greeks, in particular, their mathematical genius, to lay the foundations of the true science of astronomy. In this classic study, a noted scholar discusses in lucid detail the specific advances made by the Greeks, many of whose ideas anticipated the discoveries of modern astronomy.Pythagoras, born at Samos about 572 B.C., was probably the first

Ground-based photo monitoring

Science.gov (United States)

Frederick C. Hall

2000-01-01

Ground-based photo monitoring is repeat photography using ground-based cameras to document change in vegetation or soil. Assume those installing the photo location will not be the ones re-photographing it. This requires a protocol that includes: (1) a map to locate the monitoring area, (2) another map diagramming the photographic layout, (3) type and make of film such...

Space and astronomy

CERN Document Server

Kirkland, Kyle

2010-01-01

Some daring explorers like to study distant frontiers by venturing out into them, but others prefer to study them by bringing them, or representative samples, a little closer to the lab. Both options are pursued in the fields of space and astronomy. Space exploration and astronomy are intricately linked and are examined in-depth in this guide. Dedicated to the scientists who explore the frontiers of space and astronomy-and the results of their unfamiliar findings-each chapter in Space and Astronomy explores one of the frontiers of this science. The development of technology, such as rocket pro

Journal of Astrophysics and Astronomy | Indian Academy of Sciences

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... However, the application of ground-based magnetometer arrays has proven to be one of the most successful methods of studying the spatial structure of hydromagnetic waves in the earth's magnetosphere. The solar wind provides the energy for the earth's magnetospheric processes. Pc3-5 geomagnetic ...

A Numerical Study on the Screening of Blast-Induced Waves for Reducing Ground Vibration

Science.gov (United States)

Park, Dohyun; Jeon, Byungkyu; Jeon, Seokwon

2009-06-01

Blasting is often a necessary part of mining and construction operations, and is the most cost-effective way to break rock, but blasting generates both noise and ground vibration. In urban areas, noise and vibration have an environmental impact, and cause structural damage to nearby structures. Various wave-screening methods have been used for many years to reduce blast-induced ground vibration. However, these methods have not been quantitatively studied for their reduction effect of ground vibration. The present study focused on the quantitative assessment of the effectiveness in vibration reduction of line-drilling as a screening method using a numerical method. Two numerical methods were used to analyze the reduction effect toward ground vibration, namely, the “distinct element method” and the “non-linear hydrocode.” The distinct element method, by particle flow code in two dimensions (PFC 2D), was used for two-dimensional parametric analyses, and some cases of two-dimensional analyses were analyzed three-dimensionally using AUTODYN 3D, the program of the non-linear hydrocode. To analyze the screening effectiveness of line-drilling, parametric analyses were carried out under various conditions, with the spacing, diameter of drill holes, distance between the blasthole and line-drilling, and the number of rows of drill holes, including their arrangement, used as parameters. The screening effectiveness was assessed via a comparison of the vibration amplitude between cases both with and without screening. Also, the frequency distribution of ground motion of the two cases was investigated through fast Fourier transform (FFT), with the differences also examined. From our study, it was concluded that line-drilling as a screening method of blast-induced waves was considerably effective under certain design conditions. The design details for field application have also been proposed.

The Parametric Instability of Alfven Waves: Effects of Temperature Anisotropy

Czech Academy of Sciences Publication Activity Database

Tenerani, A.; Velli, M.; Hellinger, Petr

2017-01-01

Roč. 851, č. 2 (2017), 99/1-99/9 ISSN 0004-637X R&D Projects: GA ČR GA15-10057S Institutional support: RVO:67985815 Keywords : instabilities * plasmas * waves Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.533, year: 2016

The Japanese space gravitational wave antenna; DECIGO

OpenAIRE

Kawamura, Seiji; Ando, Masaki; Nakamura, Takashi; Tsubono, Kimio; Tanaka, Takahiro; Funaki, Ikkoh; Seto, Naoki; Numata, Kenji; Sato, Shuichi; Ioka, Kunihito; Kanda, Nobuyuki; Takashima, Takeshi; Agatsuma, Kazuhiro; Akutsu, Tomotada; Akutsu, Tomomi

2008-01-01

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. The goal of DECIGO is to detect gravitational waves from various kinds of sources mainly between 0.1 Hz and 10 Hz and thus to open a new window of observation for gravitational wave astronomy. DECIGO will consist of three drag-free spacecraft, 1000 km apart from each other, whose relative displacements are measured by a Fabry—Perot Michelson interferometer. We plan to lau...

The Japanese space gravitational wave antenna - DECIGO

OpenAIRE

Kawamura, Seiji; Ando, Masaki; Nakamura, Takashi; Tsubono, Kimio; Tanaka, Takahiro; Funaki, Iklkoh; Seto, Naoki; Numata, Kenji; Sato, Shuichi; Ioka, Kunihito; Kanda, Nobuyuki; Takashima, Takeshi; Agatsuma, Kazuhiro; Akutsu, Tomotada; Akutsu, Tomomi

2008-01-01

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. The goal of DECIGO is to detect gravitational waves from various kinds of sources mainly between 0.1 Hz and 10 Hz and thus to open a new window of observation for gravitational wave astronomy. DECIGO will consist of three drag-free spacecraft, 1000 km apart from each other, whose relative displacements are measured by a Fabry—Perot Michelson interferometer. We plan to lau...

Short-Period Surface Wave Based Seismic Event Relocation

Science.gov (United States)

White-Gaynor, A.; Cleveland, M.; Nyblade, A.; Kintner, J. A.; Homman, K.; Ammon, C. J.

2017-12-01

Accurate and precise seismic event locations are essential for a broad range of geophysical investigations. Superior location accuracy generally requires calibration with ground truth information, but superb relative location precision is often achievable independently. In explosion seismology, low-yield explosion monitoring relies on near-source observations, which results in a limited number of observations that challenges our ability to estimate any locations. Incorporating more distant observations means relying on data with lower signal-to-noise ratios. For small, shallow events, the short-period (roughly 1/2 to 8 s period) fundamental-mode and higher-mode Rayleigh waves (including Rg) are often the most stable and visible portion of the waveform at local distances. Cleveland and Ammon [2013] have shown that teleseismic surface waves are valuable observations for constructing precise, relative event relocations. We extend the teleseismic surface wave relocation method, and apply them to near-source distances using Rg observations from the Bighorn Arche Seismic Experiment (BASE) and the Earth Scope USArray Transportable Array (TA) seismic stations. Specifically, we present relocation results using short-period fundamental- and higher-mode Rayleigh waves (Rg) in a double-difference relative event relocation for 45 delay-fired mine blasts and 21 borehole chemical explosions. Our preliminary efforts are to explore the sensitivity of the short-period surface waves to local geologic structure, source depth, explosion magnitude (yield), and explosion characteristics (single-shot vs. distributed source, etc.). Our results show that Rg and the first few higher-mode Rayleigh wave observations can be used to constrain the relative locations of shallow low-yield events.

Opportunities and challenges for time domain astronomy with LSST

Science.gov (United States)

Ivezic, Zeljko

2014-01-01

The Large Synoptic Survey Telescope (LSST) will enable faint optical time-domain astronomy by carrying out an imaging survey covering the sky that is visible from Cerro Pachon in Northern Chile. Of the order thousand 9.6 sq. deg. images (3.2 Gigapix) will be obtained per night using pairs of 15-second back-to-back exposures, with typical 5-sigma depth for point sources of 24.5 (AB). With close to 1000 observations of a 18,000 sq. deg. region in ugrizy bands over a 10-year period, these data will enable a deep stack across half the sky reaching five magnitudes deeper than the SDSS survey ( 27.5, 5 sigma, point source), and with twice as good seeing (0.7 arcsec median seeing in the r band). The measured and archived properties of newly discovered and known astrometric and photometric transients will be publicly reported within 60 sec after closing the shutter. Automated classification of the expected several million alerts per night, and selection of transient events requiring immediate follow-up, is an outstanding problem for the community. These data will represent a treasure trove for follow-up programs using other ground and space-based telescopes, such as fast-response fast-cadence photometric observations and spectroscopy, as well as for facilities operating at non-optical wavelengths and for gravitational wave programs. I will describe the relevant data products to be delivered by LSST and will summarize challenges that will need to be addressed by the community at large.

Strong Sporadic E Occurrence Detected by Ground-Based GNSS

Science.gov (United States)

Sun, Wenjie; Ning, Baiqi; Yue, Xinan; Li, Guozhu; Hu, Lianhuan; Chang, Shoumin; Lan, Jiaping; Zhu, Zhengping; Zhao, Biqiang; Lin, Jian

2018-04-01

The ionospheric sporadic E (Es) layer has significant impact on radio wave propagation. The traditional techniques employed for Es layer observation, for example, ionosondes, are not dense enough to resolve the morphology and dynamics of Es layer in spatial distribution. The ground-based Global Navigation Satellite Systems (GNSS) technique is expected to shed light on the understanding of regional strong Es occurrence, owing to the facts that the critical frequency (foEs) of strong Es structure is usually high enough to cause pulse-like disturbances in GNSS total electron content (TEC), and a large number of GNSS receivers have been deployed all over the world. Based on the Chinese ground-based GNSS networks, including the Crustal Movement Observation Network of China and the Beidou Ionospheric Observation Network, a large-scale strong Es event was observed in the middle latitude of China. The strong Es shown as a band-like structure in the southwest-northeast direction extended more than 1,000 km. By making a comparative analysis of Es occurrences identified from the simultaneous observations by ionosondes and GNSS TEC receivers over China middle latitude statistically, we found that GNSS TEC can be well employed to observe strong Es occurrence with a threshold value of foEs, 14 MHz.

On the Development and Evolution of Astronomy in ancient Egypt

Science.gov (United States)

Maravelias, S. E.

In the present paper the development and evolution of astronomy in = Ancient Egypt are briefly examined. Emphasis is given to the = applications of astronomy on: (i) the orientation of temples and = pyramids, and the subsequent determination of the year; (ii) the = reorientation of temples --after the lapse of several centuries-- (due = to the fact that the priesthood was empirically aware of the precession = of equinoxes, and the subsequent use of this very fact in order to = estimate the archaeological age of temples, tombs and pyramids; (iii) = the heliacal rising of Sirius, which was used by ancient = priests-astronomers in order to fix the New Year's Day and determine the = seasons of the civil year, although the discre pancy of the Sothic cycle = in their calendrical system was not seriously taken into account. = Finally the conclusion put forward is that astronomy in Ancient Egypt = never reached the grounds of pure science (as in Ancient Greece), at = least before the Ptolemaic era, but always remained under the influence = of traditionalism and mythology pertaining more to the sphere of = religion and dogma.

Open high-level data formats and software for gamma-ray astronomy

Science.gov (United States)

Deil, Christoph; Boisson, Catherine; Kosack, Karl; Perkins, Jeremy; King, Johannes; Eger, Peter; Mayer, Michael; Wood, Matthew; Zabalza, Victor; Knödlseder, Jürgen; Hassan, Tarek; Mohrmann, Lars; Ziegler, Alexander; Khelifi, Bruno; Dorner, Daniela; Maier, Gernot; Pedaletti, Giovanna; Rosado, Jaime; Contreras, José Luis; Lefaucheur, Julien; Brügge, Kai; Servillat, Mathieu; Terrier, Régis; Walter, Roland; Lombardi, Saverio

2017-01-01

In gamma-ray astronomy, a variety of data formats and proprietary software have been traditionally used, often developed for one specific mission or experiment. Especially for ground-based imaging atmospheric Cherenkov telescopes (IACTs), data and software are mostly private to the collaborations operating the telescopes. However, there is a general movement in science towards the use of open data and software. In addition, the next-generation IACT instrument, the Cherenkov Telescope Array (CTA), will be operated as an open observatory. We have created a Github organisation at https://github.com/open-gamma-ray-astro where we are developing high-level data format specifications. A public mailing list was set up at https://lists.nasa.gov/mailman/listinfo/open-gamma-ray-astro and a first face-to-face meeting on the IACT high-level data model and formats took place in April 2016 in Meudon (France). This open multi-mission effort will help to accelerate the development of open data formats and open-source software for gamma-ray astronomy, leading to synergies in the development of analysis codes and eventually better scientific results (reproducible, multi-mission). This write-up presents this effort for the first time, explaining the motivation and context, the available resources and process we use, as well as the status and planned next steps for the data format specifications. We hope that it will stimulate feedback and future contributions from the gamma-ray astronomy community.

Imaging X-ray astronomy

International Nuclear Information System (INIS)

Elvis, M.

1990-01-01

The launch of the High Energy Astrophysical Observatory, more appealingly called the Einstein Observatory, marked one of the most revolutionary steps taken in astrophysics this century. Its greater sensitivity compared with earlier satellites and its ability to make high spacial and spectral resolution observations transformed X-ray astronomy. This book is based on a Symposium held in Cambridge, Massachusetts, to celebrate a decade of Einstein Observatory's achievements. It discusses the contributions that this satellite has made to each area of modern astrophysics and the diversity of the ongoing work based on Einstein data. There is a guide to each of the main data bases now coming on-line to increase the availability and to preserve this valuable archive for the future. A review of NASA's next big X-ray mission, AXAF, and a visionary program for novel X-ray astronomy satellites by Riccardo Giacconi conclude this wide-ranging volume. (author)

Grist: Grid-based Data Mining for Astronomy

Science.gov (United States)

Jacob, J. C.; Katz, D. S.; Miller, C. D.; Walia, H.; Williams, R. D.; Djorgovski, S. G.; Graham, M. J.; Mahabal, A. A.; Babu, G. J.; vanden Berk, D. E.; Nichol, R.

2005-12-01

The Grist project is developing a grid-technology based system as a research environment for astronomy with massive and complex datasets. This knowledge extraction system will consist of a library of distributed grid services controlled by a workflow system, compliant with standards emerging from the grid computing, web services, and virtual observatory communities. This new technology is being used to find high redshift quasars, study peculiar variable objects, search for transients in real time, and fit SDSS QSO spectra to measure black hole masses. Grist services are also a component of the ``hyperatlas'' project to serve high-resolution multi-wavelength imagery over the Internet. In support of these science and outreach objectives, the Grist framework will provide the enabling fabric to tie together distributed grid services in the areas of data access, federation, mining, subsetting, source extraction, image mosaicking, statistics, and visualization.

Grist : grid-based data mining for astronomy

Science.gov (United States)

Jacob, Joseph C.; Katz, Daniel S.; Miller, Craig D.; Walia, Harshpreet; Williams, Roy; Djorgovski, S. George; Graham, Matthew J.; Mahabal, Ashish; Babu, Jogesh; Berk, Daniel E. Vanden;

Gravitational Waves: An Entirely New Window onto the Cosmos

CERN Multimedia

CERN. Geneva

2017-01-01

On September 14, 2015, scientists from the LIGO Scientific Collaboration and the Virgo Collaboration using the LIGO detectors observed the collision and fusion of two black holes by directly measuring the gravitational waves emitted during their collision.  This detection came almost exactly 100 years after Einstein developed his revolutionary general theory of relativity that predicted their existence, and 50 years after scientists began searching for them in earnest.  Since then, two more gravitational-wave events have been confidently detected. These discoveries have truly profound implications for physics and astronomy.   Gravitational waves provide unique information on the most energetic astrophysical events, revealing unique insights into the nature of gravity, matter, space, and time. LIGO has opened a new window onto the cosmos.  I will talk about how we made the detection and discuss how gravitational wave astronomy promises to change our understanding o...

Ground States of Random Spanning Trees on a D-Wave 2X

Science.gov (United States)

Hall, J. S.; Hobl, L.; Novotny, M. A.; Michielsen, Kristel

The performances of two D-Wave 2 machines (476 and 496 qubits) and of a 1097-qubit D-Wave 2X were investigated. Each chip has a Chimera interaction graph calG . Problem input consists of values for the fields hj and for the two-qubit interactions Ji , j of an Ising spin-glass problem formulated on calG . Output is returned in terms of a spin configuration {sj } , with sj = +/- 1 . We generated random spanning trees (RSTs) uniformly distributed over all spanning trees of calG . On the 476-qubit D-Wave 2, RSTs were generated on the full chip with Ji , j = - 1 and hj = 0 and solved one thousand times. The distribution of solution energies and the average magnetization of each qubit were determined. On both the 476- and 1097-qubit machines, four identical spanning trees were generated on each quadrant of the chip. The statistical independence of these regions was investigated. In another study, on the D-Wave 2X, one hundred RSTs with random Ji , j ∈ { - 1 , 1 } and hj = 0 were generated on the full chip. Each RST problem was solved one hundred times and the number of times the ground state energy was found was recorded. This procedure was repeated for square subgraphs, with dimensions ranging from 7 ×7 to 11 ×11. Supported in part by NSF Grants DGE-0947419 and DMR-1206233. D-Wave time provided by D-Wave Systems and by the USRA Quantum Artificial Intelligence Laboratory Research Opportunity.

Seismic Response of Power Transmission Tower-Line System Subjected to Spatially Varying Ground Motions

Directory of Open Access Journals (Sweden)

Li Tian

2010-01-01

Full Text Available The behavior of power transmission tower-line system subjected to spatially varying base excitations is studied in this paper. The transmission towers are modeled by beam elements while the transmission lines are modeled by cable elements that account for the nonlinear geometry of the cables. The real multistation data from SMART-1 are used to analyze the system response subjected to spatially varying ground motions. The seismic input waves for vertical and horizontal ground motions are also generated based on the Code for Design of Seismic of Electrical Installations. Both the incoherency of seismic waves and wave travel effects are accounted for. The nonlinear time history analytical method is used in the analysis. The effects of boundary conditions, ground motion spatial variations, the incident angle of the seismic wave, coherency loss, and wave travel on the system are investigated. The results show that the uniform ground motion at all supports of system does not provide the most critical case for the response calculations.

Ground state of charged Base and Fermi fluids in strong coupling

International Nuclear Information System (INIS)

Mazighi, R.

1982-03-01

The ground state and excited states of the charged Bose gas were studied (wave function, equation of state, thermodynamics, application of Feynman theory). The ground state of the charged Fermi gas was also investigated together with the miscibility of charged Bose and Fermi gases at 0 deg K (bosons-bosons, fermions-bosons and fermions-fermions) [fr

Perturbations of ionosphere-magnetosphere coupling by powerful VLF emissions from ground-based transmitters

International Nuclear Information System (INIS)

Belov, A. S.; Markov, G. A.; Ryabov, A. O.; Parrot, M.

2012-01-01

The characteristics of the plasma-wave disturbances stimulated in the near-Earth plasma by powerful VLF radiation from ground-based transmitters are investigated. Radio communication VLF transmitters of about 1 MW in power are shown to produce artificial plasma-wave channels (density ducts) in the near-Earth space that originate in the lower ionosphere above the disturbing emission source and extend through the entire ionosphere and magnetosphere of the Earth along the magnetic field lines. Measurements with the onboard equipment of the DEMETER satellite have revealed that under the action of emission from the NWC transmitter, which is one of the most powerful VLF radio transmitters, the generation of quasi-electrostatic (plasma) waves is observed on most of the satellite trajectory along the disturbed magnetic flux tube. This may probably be indicative of stimulated emission of a magnetospheric maser.

iSTAR: The International STudy on Astronomy Reasoning

Science.gov (United States)

Tatge, Coty B.; Slater, Timothy F.; Slater, Stephanie J.

2015-08-01

This paper reports the first steps taken in the International STudy on Astronomy Reasoning (iSTAR). The iSTAR Project is an attempt to look beyond traditional wisdom and practices in astronomy education, to discover the ways in which cognitive abilities and human culture interact to impact individuals’ understanding of and relationship to astronomy content knowledge. In contrast to many international studies that seek to rank nations by student performance on standardized tests, the iSTAR Project seeks to find ways that culture may unexpectedly enhance performance in astronomy. Using the Test of Astronomy Standards (TOAST) as a reasonable, initial proxy for the content knowledge a well educated person might know in astronomy, the iSTAR team then defined culture as a construct with five components: practices, traditional knowledge, historical and genealogical relationships, place-based knowledge, and language. Given the complexity of this construct, Stage 1 of the project focuses on the cultural component of language, and assumed that prior to the collection of data from students, the process of translating the TOAST could provide valuable expert-based information on the impact of language on astronomy knowledge. As such, the work began with a study of the translation process. For each of the languages used in the testing phase of the iSTAR protocol, a succession of translators and analysts were engaged, including two educated, non-astronomer native speakers, a native speaking astronomer, and a native speaking linguistics expert. Multiple translations were analyzed in order to make relevant meaning of differences in the translations, and provide commentary on the ways in which metaphor, idiom, cultural history are embedded in the language, providing potential advantages in the learning of astronomy. The first test languages were German, Hawaiian, and American Sign Language, and initial findings suggest that each of these languages provide specific advantages

Application of Coupled-Wave Wentzel-Kramers-Brillouin Approximation to Ground Penetrating Radar

OpenAIRE

Igor Prokopovich; Alexei Popov; Lara Pajewski; Marian Marciniak

2017-01-01

This paper deals with bistatic subsurface probing of a horizontally layered dielectric half-space by means of ultra-wideband electromagnetic waves. In particular, the main objective of this work is to present a new method for the solution of the two-dimensional back-scattering problem arising when a pulsed electromagnetic signal impinges on a non-uniform dielectric half-space; this scenario is of interest for ground penetrating radar (GPR) applications. For the analytical description of the s...

Event Rates of Gravitational Waves from merging Intermediate mass Black Holes: based on a Runaway Path to a SMBH

Science.gov (United States)

Shinkai, Hisaaki

2018-01-01

Based on a dynamical formation model of a supermassive black hole (SMBH), we estimate the expected observational profile of gravitational wave at ground-based detectors, such as KAGRA or advanced LIGO/VIRGO. Noting that the second generation of detectors have enough sensitivity from 10 Hz and up, we are able to detect the ring-down gravitational wave of a BH with the mass M 1 per year for ρ = 10. Thus, if we observe a BH with more than 100M⊙ in future gravitational-wave observations, our model naturally explains its source.

The Networks Of The Astronomical Society Of The Pacific And The International Year Of Astronomy

Science.gov (United States)

Fraknoi, Andrew; Manning, J.; Gurton, S.; Gibbs, M.; Hurst, A.; White, V.; Berendsen, M.

2007-12-01

Serious planning has begun for the International Year of Astronomy (IYA) in 2009, which will also be the 120th anniversary of the Astronomical Society of the Pacific (ASP). A key element required for IYA's success in reaching the maximum number of people in the U.S. will be to find effective ways of disseminating the programs and materials that are being developed. The ASP's national networks of educational intermediaries can play a major role in training, dissemination, and organization for IYA. These networks include: the Project ASTRO National Site Network (13 regional sites training professional and amateur astronomers to work with local teachers and families), the Night Sky Network (over 200 amateur astronomy clubs engaged in active outreach), the Astronomy from the Ground Up Network (smaller science and nature centers increasing their offerings in astronomy), and the Cosmos in the Classroom Network (hundreds of instructors of introductory astronomy in community, state, and liberal arts colleges). The ASP also offers "The Universe in the Classroom", a quarterly newsletter for those teaching astronomy in grades 3-12, an extensive web site of educational resources, podcasts, workshops, national conferences, and awards to help improve the public understanding of astronomy. At the Summer 2008 AAS meeting, the ASP will sponsor a major symposium and workshops on preparing for IYA (and working with a range of different audiences.)

Model-based internal wave processing

Energy Technology Data Exchange (ETDEWEB)

Candy, J.V.; Chambers, D.H.

1995-06-09

A model-based approach is proposed to solve the oceanic internal wave signal processing problem that is based on state-space representations of the normal-mode vertical velocity and plane wave horizontal velocity propagation models. It is shown that these representations can be utilized to spatially propagate the modal (dept) vertical velocity functions given the basic parameters (wave numbers, Brunt-Vaisala frequency profile etc.) developed from the solution of the associated boundary value problem as well as the horizontal velocity components. Based on this framework, investigations are made of model-based solutions to the signal enhancement problem for internal waves.

Astronomy 3.0 Style

Science.gov (United States)

Accomazzi, A.

2010-10-01

Over the next decade, we will witness the development of a new infrastructure in support of data-intensive scientific research, which includes Astronomy. This new networked environment will offer both challenges and opportunities to our community and has the potential to transform the way data are described, curated and preserved. Based on the lessons learned during the development and management of the ADS, a case is made for adopting the emerging technologies and practices of the Semantic Web to support the way Astronomy research will be conducted. Examples of how small, incremental steps can, in the aggregate, make a significant difference in the provision and repurposing of astronomical data are provided.

The Collection of Data for the Research Component of the Internet-Based, ``Doctor of Astronomy'' Professional Degree Program at James Cook University

Science.gov (United States)

Millar, W.; White, G. L.; Filipović, M. D.; Hons, A.

2008-06-01

We discuss the means by which students collect, analyze and use original data to fulfill the research component of the Internet-based, professional ``Doctor of Astronomy'' degree, at the James Cook University Centre for Astronomy. We give an example of such data obtained with the 1.9 meter telescope at the South African Astronomical Observatory. We also discuss the use of such data in an introductory level astronomy class at a community college.

Advances in astronomy and astrophysics

CERN Document Server

Kopal, Zdenek

1966-01-01

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

Spacelab Level 4 Programmatic Implementation Assessment Study. Volume 2: Ground Processing requirements

Science.gov (United States)

1978-01-01

Alternate ground processing options are summarized, including installation and test requirements for payloads, space processing, combined astronomy, and life sciences. The level 4 integration resource requirements are also reviewed for: personnel, temporary relocation, transportation, ground support equipment, and Spacelab flight hardware.

Dark Skies are a Universal Resource: Programs Planned for the International Year of Astronomy

Science.gov (United States)

Walker, Constance E.; US IYA Dark Skies Working Group

2008-05-01

The dark night sky is a natural resource that is being lost by much of the world's population. This loss is a growing, serious issue that impacts not only astronomical research, but also human health, ecology, safety, economics and energy conservation. One of the themes of the US Node targeted for the International Year of Astronomy (IYA) is "Dark Skies are a Universal Resource". The goal is to raise public awareness of the impact of artificial lighting on local environments by getting people involved locally in a variety of dark skies-related events. To reach this goal, activities are being developed that: 1) Teach about dark skies using new technology (e.g., an activity-based planetarium show on DVD, podcasting, social networking) 2) Provide thematic events on light pollution at star parties and observatory open houses (Dark Skies Teaching Sites, Astronomy Nights in the (National) Parks, Sidewalk Astronomy Nights) 3) Organize events in the arts (e.g., a photography contest) 4) Involve citizen-scientists in unaided-eye and digital-meter star counting programs (e.g., GLOBE at Night, "How Many Stars?” and the Great World Wide Star Count) and 5) Raise awareness about the link between light pollution and public health, economic issues, ecological consequences, energy conservation, safety and security (e.g., The Great Switch Out, Earth Hour, National Dark Skies Week, traveling exhibits and a 6-minute video tutorial on lighting issues). To deliver these programs, strategic networks have been established with the ASP's Night Sky Network's astronomy clubs, Astronomy from the Ground Up's science and nature centers and the Project and Family ASTRO programs, as well as the International Dark-Sky Association, GLOBE and the Astronomical League, among others. The poster presentation will outline the activities being developed, the plans for funding, implementation, marketing and the connections to the global cornerstone IYA project, "Dark Skies Awareness".

Site Classification using Multichannel Channel Analysis of Surface Wave (MASW) method on Soft and Hard Ground

Science.gov (United States)

Ashraf, M. A. M.; Kumar, N. S.; Yusoh, R.; Hazreek, Z. A. M.; Aziman, M.

2018-04-01

Site classification utilizing average shear wave velocity (Vs(30) up to 30 meters depth is a typical parameter. Numerous geophysical methods have been proposed for estimation of shear wave velocity by utilizing assortment of testing configuration, processing method, and inversion algorithm. Multichannel Analysis of Surface Wave (MASW) method is been rehearsed by numerous specialist and professional to geotechnical engineering for local site characterization and classification. This study aims to determine the site classification on soft and hard ground using MASW method. The subsurface classification was made utilizing National Earthquake Hazards Reduction Program (NERHP) and international Building Code (IBC) classification. Two sites are chosen to acquire the shear wave velocity which is in the state of Pulau Pinang for soft soil and Perlis for hard rock. Results recommend that MASW technique can be utilized to spatially calculate the distribution of shear wave velocity (Vs(30)) in soil and rock to characterize areas.

Infrared Astronomy and Education: Linking Infrared Whole Sky Mapping with Teacher and Student Research

Science.gov (United States)

Borders, Kareen; Mendez, Bryan; Thaller, Michelle; Gorjian, Varoujan; Borders, Kyla; Pitman, Peter; Pereira, Vincent; Sepulveda, Babs; Stark, Ron; Knisely, Cindy; Dandrea, Amy; Winglee, Robert; Plecki, Marge; Goebel, Jeri; Condit, Matt; Kelly, Susan

The Spitzer Space Telescope and the recently launched WISE (Wide Field Infrared Survey Explorer) observe the sky in infrared light. Among the objects WISE will study are asteroids, the coolest and dimmest stars, and the most luminous galaxies. Secondary students can do authentic research using infrared data. For example, students will use WISE data to mea-sure physical properties of asteroids. In order to prepare students and teachers at this level with a high level of rigor and scientific understanding, the WISE and the Spitzer Space Tele-scope Education programs provided an immersive teacher professional development workshop in infrared astronomy.The lessons learned from the Spitzer and WISE teacher and student pro-grams can be applied to other programs engaging them in authentic research experiences using data from space-borne observatories such as Herschel and Planck. Recently, WISE Educator Ambassadors and NASA Explorer School teachers developed and led an infrared astronomy workshop at Arecibo Observatory in PuertoRico. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance and age of objects in the Universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and the Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. We will outline specific steps for sec-ondary astronomy professional development, detail student involvement in infrared telescope data analysis, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional secondary professional development and student involvement in infrared astronomy. Funding was

Astronomy Enrollments and Degrees: Results from the 2012 Survey of Astronomy Enrollments and Degrees. Focus On

Science.gov (United States)

Mulvey, Patrick; Nicholson, Starr

2014-01-01

Interest in astronomy degrees in the U.S. remains strong, with astronomy enrollments at or near all-time highs for the 2012-13 academic year. The total number of students taking an introductory astronomy course at a degree-granting physics or astronomy department is approaching 200,000. Enrollments in introductory astronomy courses have been…

Astronomy at the frontiers of science

CERN Document Server

2011-01-01

Astronomy is by nature an interdisciplinary activity: it involves mathematics, physics, chemistry and biology. Astronomers use (and often develop) the latest technology, the fastest computers and the most refined software.  In this book twenty-two leading scientists from nine countries talk about how astronomy interacts with these other sciences. They describe modern instruments used in astronomy and the relations between astronomy and technology, industry, politics and philosophy. They also discuss what it means to be an astronomer, the history of astronomy, and the place of astronomy in society today.   The book contains twenty chapters grouped in four parts: ASTRONOMY AND PHYSICS discusses the place of astronomy among various branches of (mostly high-energy) physics. ASTRONOMY IN SOCIETY describes not only the historical context of astronomy, but issues facing astronomers today, including funding, planning, worldwide collaboration and links with industry. THE TOOLS OF OBSERVATION AND THE PROFESSION OF AS...

Dorrit Hoffleit: A Century of being a Woman in Astronomy

Science.gov (United States)

Hoffleit, Dorrit; Gay, P. L.

2006-12-01

From working as one of Harlan J. Smith's female calculators in 1928 to running Maria Mitchell Observatory in 1957 to being an emeritus research scientist at Yale University today, Dr. Dorrit Hoffleit has been a professional woman in astronomy for 78 years and an astronomy lover for a century. She has faced both accolades, starting with the Carolyn Wilby Prize in 1938 for her dissertation work, as well as discrimination, most notably being hired at the Aberdeen Proving Ground at a sub-professional rating during WWII. Through both good and bad, she kept her eye on the stars, and her focus on doing the best work she could. In this presentation, Dr. Hoffleit reflects on her experiences and her inspirations in an video-interview. Additionally, archival film provided by the AAVSO will be shown.

First detections of gravitational waves from binary black holes

International Nuclear Information System (INIS)

Bejger, Michał

2017-01-01

Recent direct detections of gravitational waves from coalescing binary black holes systems herald a new era in the observational astronomy, as well as in experimental verifications of the theories of gravity. I will present the principles of detection of gravitational waves, current state-of-art laser interferometric detectors (Advanced LIGO and Advanced Virgo), and the most promising astrophysical sources of gravitational waves. (paper)

Evolving Perspectives on Astronomy Education and Public Outreach in Hawai'i

Science.gov (United States)

Kimura, Ka'iu; Slater, T.; Hamilton, J.; Takata, V.

2012-01-01

For the last several decades, well meaning astronomers and educators have worked diligently to provide astronomy education experiences to Native Hawaiians and visitors across all the islands. Much of the early education and public outreach (EPO) work was based on a philosophical perspective based on the notion of, "if we just make them aware of how wonderful astronomy is, then everyone will naturally support the development of astronomy in the islands.” In support of this goal, numerous teacher workshops were delivered and the first generation of the Maunakea Observatories Visitors’ Center was developed and funded. These projects were most frequently developed using Mainland thinking, in a Mainland style, with a Mainland agenda. Consequently, these efforts often failed to create even moderate impacts, whether in educational settings, or in terms of public outreach. In recent years, our understanding of effective EPO has evolved. This evolution has led to a shift in the locus of control, from the Mainland to the Islands; and in content, from "astronomy only” to "astronomy as part of the whole.” We have come to understand that successfully transformative EPO requires intertwining astronomy with teaching about culture, language and context. In response, the `Imiloa Astronomy Center was expanded to convolve historical and modern astronomy with Hawaiian culture and language. Moreover, the most successful astronomy EPO programs in the islands have been redesigned to reflect meaningful collaborations of schools, businesses, and the larger community that situate astronomy as part of a larger educational work of honoring the traditions of the past while simultaneously transforming the future. This evolution in thinking may serve as a model for the astronomy community's interaction with other regional communities.

VLF wave injections from the ground

Science.gov (United States)

Helliwell, R. A.

1983-01-01

Experiments on wave-particle interactions using VLF whistler-mode waves injected into the magnetosphere from Antartica are described. The injected signals are single-frequency coherent waves whose amplitudes and frequencies may be changed slowly with time, or else two or more coherent wave trains transmitted simultaneously to determine the nature of the response to multifrequency excitation. The waves may be amplified 30 dB or more and may trigger intense emissions having bandwidths that vary from a few to several hundred Hertz. In most cases significant growth and triggering occur only when the driving signal is essentially monochromatic (bandwidth 10 Hz). If two frequencies are transmitted simultaneously the signal at the lower frequency tends to be suppressed by 20 dB or more. These results are interpreted in terms of a feedback interaction between the waves and counter-streaming cyclotron resonant electrons in a region several hundred wavelengths long, centered on the magnetic equator.

Highschool astronomy research workshop in Thailand and how it transforms Thai astronomy education

Science.gov (United States)

Tangmatitham, Matipon

2017-01-01

The National Astronomical Research Institute of Thailand (NARIT) have launched the program "Advance Teacher Training Workshop" that aims to introduce both the students and astronomy teacher alike to the nature of critical thinking in science via hands on experience in astronomy projects. Students and accompanying teachers are participated in 5 days workshop in which each of them must select an individual astronomy research project. The project is then carried out on their own for the next 6 months, after which their works are presented in a conference. Progress is monitored and extra aid is delivered as needed via the use of social media. Over a hundred projects have been completed under this program. Follow up study have suggests that this workshop has shown to be quite successful at improving critical thinking skills in participants. As the program became more popular, other schools began to follow. To support the growing interest, we have also launched the "Thai Astronomical Society: student session", a highschool astronomy conference for anyone who participated or interested in astronomy related projects. Via these stages we are able to secure a permanent foothold in Thai astronomy education and inspire new generations to participate in astronomy projects.

Bolometers for far-infrared and submillimetre astronomy

International Nuclear Information System (INIS)

Griffin, M.J.

2000-01-01

Important scientific goals of far-infrared and submillimetre astronomy include measurements of anisotropies in the cosmic background radiation, deep imaging surveys for detection of high-red-shift galaxies, and imaging and spectroscopy of star formation regions and the interstellar medium in the milky way and nearby galaxies. Use of sensitive bolometer arrays leads to very large improvements in observing speed. Recent progress in the development of bolometric detector systems for ground-based and space-borne far-infrared and submillimetre astronomical observations is reviewed, including spider-web NTD bolometers, transition-edge superconducting sensors, and micromachined planar arrays of ion-implanted silicon bolometers. Future arrays may be based on planar absorbers without feedhorns, which offer potential advantages including more efficient use of space in the focal plane and improved instantaneous sampling of the telescope point spread function, but present challenges in suppression of stray light and RF interference. FIRST and Planck Surveyor are planned satellite missions involving passively cooled (∼70 K) telescopes, and bolometer array developments for these missions are described

Observational astrophysics.

Science.gov (United States)

Léna, P.; Lebrun, F.; Mignard, F.

This book is the 2nd edition of an English translation published in 1988 (45.003.105) of the French original "Astrophysique: Méthodes physiques de l'observation" published in 1986 (42.003.048). Written specifically for physicists and graduate students in astronomy, this textbook focuses on astronomical observation and on the basic physical principles that astronomers use to conceive, build and exploit their instruments at their ultimate limits in sensitivity or resolution. This second edition has been entirely restructured and almost doubled in size, in order to improve its clarity and to account for the great progress achieved in the last 15 years. It deals with ground-based and space-based astronomy and their respective fields. It presents the new generation of giant ground-based telescopes, with the new methods of optical interferometry and adaptive optics, and also the ambitious concepts behind planned space missions for the next decades. Avoiding particulars, it covers the whole of the electromagnetic spectrum and touches upon the "new astronomies" becoming possible with gravitational waves and neutrinos.

Section on prospects for dark matter detection of the white paper on the status and future of ground-based TeV gamma-ray astronomy.

Energy Technology Data Exchange (ETDEWEB)

Byrum, K.; Horan, D.; Tait, T.; Wanger, R.; Zaharijas, G.; Buckley , J.; Baltz, E. A.; Bertone, G.; Dingus, B.; Fegan, S.; Ferrer, F.; Gondolo, P.; Hall, J.; Hooper, D.; Horan, D.; Koushiappas, S.; Krawczynksi, H.; LeBohec, S.; Pohl, M.; Profumo, S.; Silk , J; Vassilev, V.; Wood , M.; Wakely, S.; High Energy Physics; FNAL; Univ. of St. Louis; Stanford Univ.; Insti. d' Astrophysique; LANL; Univ. of California; Washington Univ.; Univ. of Utah; Brown Univ.; Oxford Univ.; Iowa State Univ.; Univ. of Chicago

2009-05-13

This is a report on the findings of the dark matter science working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper was commissioned by the American Physical Society, and the full white paper can be found on astro-ph (arXiv:0810.0444). This detailed section discusses the prospects for dark matter detection with future gamma-ray experiments, and the complementarity of gamma-ray measurements with other indirect, direct or accelerator-based searches. We conclude that any comprehensive search for dark matter should include gamma-ray observations, both to identify the dark matter particle (through the characteristics of the gamma-ray spectrum) and to measure the distribution of dark matter in galactic halos.

Generalized unscented Kalman filtering based radial basis function neural network for the prediction of ground radioactivity time series with missing data

International Nuclear Information System (INIS)

Wu Xue-Dong; Liu Wei-Ting; Zhu Zhi-Yu; Wang Yao-Nan

2011-01-01

On the assumption that random interruptions in the observation process are modeled by a sequence of independent Bernoulli random variables, we firstly generalize two kinds of nonlinear filtering methods with random interruption failures in the observation based on the extended Kalman filtering (EKF) and the unscented Kalman filtering (UKF), which were shortened as GEKF and GUKF in this paper, respectively. Then the nonlinear filtering model is established by using the radial basis function neural network (RBFNN) prototypes and the network weights as state equation and the output of RBFNN to present the observation equation. Finally, we take the filtering problem under missing observed data as a special case of nonlinear filtering with random intermittent failures by setting each missing data to be zero without needing to pre-estimate the missing data, and use the GEKF-based RBFNN and the GUKF-based RBFNN to predict the ground radioactivity time series with missing data. Experimental results demonstrate that the prediction results of GUKF-based RBFNN accord well with the real ground radioactivity time series while the prediction results of GEKF-based RBFNN are divergent. (geophysics, astronomy, and astrophysics)

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

Science.gov (United States)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.;

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

Science.gov (United States)

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.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Amariutei, D. V.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; 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.; Belczynski, C.; 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.; 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.; Bork, R.; Boschi, V.; Bose, S.; 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.; 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.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; 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.; Dereli, H.; Dergachev, V.; DeRosa, R.; De Rosa, R.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Lieto, A.; 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. M.; 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.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Franco, S.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; 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.; Gatto, A.; Gaur, G.; Gehrels, N.; Gemme, G.; Gendre, B.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, A.; 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.; 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.; K, Haris; Kalaghatgi, C. V.; Kalogera, V.; 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, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, C.; Kim, J.; Kim, K.; Kim, N.; Kim, N.; 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.; 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.; 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.; Magana-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.; 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.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, 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.; 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.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Pereira, R.; Perreca, A.; Phelps, M.; Piccinni, O.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poggiani, R.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L.; 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.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; 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.; Shah, S.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; 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.; Szczepanczyk, 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 der Sluys, M. V.; 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.; 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.; 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

2016-02-01

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg2 to 20 deg2 will require at least three detectors of sensitivity within a factor of ˜ 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Teach Astronomy: An Online Resource for General Education and Informal Learning

Science.gov (United States)

Hardegree-Ullman, Kevin; Impey, C.; Patikkal, A.; Srinathan, A.; Collaboration of Astronomy Teaching Scholars CATS

2012-01-01

Teach Astronomy is a website developed for students and informal learners who would like to learn more general astronomy knowledge. This learning tool aggregates content from a myriad of sources, including: an introductory astronomy text book by C. D. Impey and W. K. Hartmann, astronomy related articles on Wikipedia, images from the Astronomy Picture of the Day, two to three minute video clips by C. D. Impey, podcasts from 365 Days of Astronomy, and news from Science Daily. In addition, Teach Astronomy utilizes a novel technology to cluster and display search results called a Wikimap. We present an overview of the website's features and suggestions for making the best use of Teach Astronomy in the classroom or at home. This material is based in part upon work supported by the National Science Foundation under Grant No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

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

Science.gov (United States)

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

Multi-Band (K- Q- and E-Band) Multi-Tone Millimeter-Wave Frequency Synthesizer for Radio Wave Propagation Studies

Science.gov (United States)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

This paper presents the design and test results of a multi-band multi-tone millimeter-wave frequency synthesizer, based on a solid-state frequency comb generator. The intended application of the synthesizer is in a space-borne transmitter for radio wave atmospheric studies at K-band (18 to 26.5 GHz), Q-band (37 to 42 GHz), and E-band (71 to 76 GHz). These studies would enable the design of robust multi-Gbps data rate space-to-ground satellite communication links. Lastly, the architecture for a compact multi-tone beacon transmitter, which includes a high frequency synthesizer, a polarizer, and a conical horn antenna, has been investigated for a notional CubeSat based space-to-ground radio wave propagation experiment.

The Virtual Wave Observatory (VWO): A Portal to Heliophysics Wave Data

Science.gov (United States)

Fung, Shing F.

2010-01-01

The Virtual Wave Observatory (VWO) is one of the discipline-oriented virtual observatories that help form the nascent NASA Heliophysics Data environment to support heliophysics research. It focuses on supporting the searching and accessing of distributed heliophysics wave data and information that are available online. Since the occurrence of a natural wave phenomenon often depends on the underlying geophysical -- i.e., context -- conditions under which the waves are generated and propagate, and the observed wave characteristics can also depend on the location of observation, VWO will implement wave-data search-by-context conditions and location, in addition to searching by time and observing platforms (both space-based and ground-based). This paper describes the VWO goals, the basic design objectives, and the key VWO functionality to be expected. Members of the heliophysics community are invited to participate in VWO development in order to ensure its usefulness and success.

Dealing with the forecast of the optical turbulence as a tool to support astronomy assisted by AO facilities

Science.gov (United States)

Masciadri, Elena; Lascaux, Franck; Fini, Luca

2015-04-01

In the context of the research activities related to the forecast of the optical turbulence and the atmospherical parameters being relevant for ground-based astronomy we focus here our attention on two specific topics: 1. pros and cons of different solutions to supply wind speed and direction stratification on the whole atmosphere all along a night to support AO facilities; 2. the necessity of instrumentation for optical turbulence monitoring (vertical profiles on the whole atmosphere) to be used operationally. In the last two decades the development and the use of different vertical profilers covering the whole atmosphere or part of it in application to the astronomy took place. Several instruments based on different principles (with associated pros and cons) have been applied in different contexts in astronomy with a main use in the site characterization and site selection. Time changed and the necessity of the astronomy supported by AO facilities is much more demanding with a diversification of applications. Recently, motivated by a precise necessity related to the identification of an absolute reference to carry out studies on optical turbulence forecasts (MOSE project), we carried out a verification of the reliability of a few instruments that lead us to put in evidence some limitations for a few of them. At the same time such a detailed analysis permitted us to clarify the nature of some astroclimatic parameters. The main conclusion at which we arrived is two-fold. From one side we could trace a list of warnings related to different uses of such instruments. On the other side we could identify open problems that indicate that there is still space for research in the field of turbulence monitoring in application to the astronomy. Some suggestions are proposed.

Information Content in Radio Waves: Student Investigations in Radio Science

Science.gov (United States)

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'.

Teaching Astronomy with Technology

Science.gov (United States)

Austin, Carmen; Impey, Chris David; Wenger, Matthew

2015-01-01

Students today are expected to have access to computers and the Internet. Students young and old, in school and out of school, are interested in learning about astronomy, and have computers to use for this. Teach Astronomy is a website with a comprehensive digital astronomy textbook freely available to students and educators. In addition to the textbook, there are astronomy Wikipedia articles, image archives from Astronomy Picture of the Day and AstroPix, and video lectures covering all topics of astronomy. Teach Astronomy has a unique search tool called the wikimap that can be used to search through all of the resources on the site. Astronomy: State of the Art (ASOTA) is a massive, open, online course (MOOC). Over 18,000 students have enrolled over the past year and half. This MOOC has been presented in various forms. First, only to students on the web, with content released weekly on host site Udemy. Then to university students who met formally in the classroom for educational activities, but were also expected to watch lectures online on their own time. Presently, it is available online for students to go at their own pace. In the future it will be available in an extended format on a new host site, Coursera. ASOTA instructors use social media to interact with students. Students ask questions via the course host site, Udemy. Live question and answer sessions are conducted using Google Hangouts on Air, and interesting and relevant astronomy news, or supplementary educational content is shared via the ASOTA Facebook page. Teaching on the Internet may seem impersonal and impractical, but by learning to use all of these tools, instructors have the ability to interact with students, and keep them engaged.

The Japanese space gravitational wave antenna - DECIGO

International Nuclear Information System (INIS)

Kawamura, S; Seto, N; Sato, S; Arai, K; Ando, M; Tsubono, K; Agatsuma, K; Akutsu, T; Akutsu, T; Arase, Y; Nakamura, T; Tanaka, T; Funaki, I; Takashima, T; Numata, K; Ioka, K; Kanda, N; Aoyanagi, Koh-Suke; Araya, A; Asada, H

2008-01-01

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. The goal of DECIGO is to detect gravitational waves from various kinds of sources mainly between 0.1 Hz and 10 Hz and thus to open a new window of observation for gravitational wave astronomy. DECIGO will consist of three drag-free spacecraft, 1000 km apart from each other, whose relative displacements are measured by a Fabry-Perot Michelson interferometer. We plan to launch DECIGO pathfinder first to demonstrate the technologies required to realize DECIGO and, if possible, to detect gravitational waves from our galaxy or nearby galaxies

Forward modeling of space-borne gravitational wave detectors

International Nuclear Information System (INIS)

Rubbo, Louis J.; Cornish, Neil J.; Poujade, Olivier

2004-01-01

Planning is underway for several space-borne gravitational wave observatories to be built in the next 10 to 20 years. Realistic and efficient forward modeling will play a key role in the design and operation of these observatories. Space-borne interferometric gravitational wave detectors operate very differently from their ground-based counterparts. Complex orbital motion, virtual interferometry, and finite size effects complicate the description of space-based systems, while nonlinear control systems complicate the description of ground-based systems. Here we explore the forward modeling of space-based gravitational wave detectors and introduce an adiabatic approximation to the detector response that significantly extends the range of the standard low frequency approximation. The adiabatic approximation will aid in the development of data analysis techniques, and improve the modeling of astrophysical parameter extraction

Basin-edge generated Rayleigh waves in the Almaty basin and corresponding consequences for ground motion amplification

Science.gov (United States)

Pilz, Marco; Parolai, Stefano; Petrovic, Bojana; Silacheva, Natalya; Abakanov, Tanatkan; Orunbaev, Sagynbek; Moldobekov, Bolot

2018-04-01

During the past two centuries, several large earthquakes have caused extensive damages in the city of Almaty in Kazakhstan. Increasing the preparedness for future events, the definition of the optimal engineering designs for civil structures and the corresponding mitigation of earthquake risks involves the accomplishment of site response studies. To this regard, a temporary seismological network of 15 stations was installed in the city aiming at the accurate identification of local variations of site response at different locations. As the city is settled on a deep sediment-filled plain with laterally strongly varying thicknesses, bound to the south by the Tien-Shan mountain range, the city might face important site effects: large amplification and significant increase of shaking duration. In addition, surface waves in the low-frequency range around and slightly higher than the fundamental resonance frequency, which could be generated at the boundaries of the basin, can carry a large amount of energy. In turn, this will influence both the spatial distribution of the level of amplification and the temporal lengthening of ground motion significantly. For quantifying these effects, we apply complex trace analysis, which uses the instantaneous polarization characteristics of the seismic signal for separating waves arriving at a single site from different directions. In this way, secondary surface waves originating at various sites along the edge of the Almaty basin can be identified as well as their generation regions. After having assessed 1-D amplification effects with well-established techniques like the standard spectral ratio and the horizontal-to-vertical spectral ratio techniques, the results further indicate that thick layers of soft clay deposits and the 3-D structure of the basin give rise to lengthening of ground motion and high amplification values at low frequencies around 0.2 Hz. The steep structure of the sediment-bedrock interface at the southern edge

Hydromagnetic Waves in the Magnetosphere and the Ionosphere

CERN Document Server

Alperovich, Leonid S

2007-01-01

The book deals with Ultra-Low-Frequency (ULF)-electromagnetic waves observed on Earth and in Space. These are so-called geomagnetic variations or pulsations. Alfvén's discovery related to the influence of the strong magnetic field on the conducting fluids (magnetohydrodynamics) led to development of the concept that the ULF-waves are magnetospheric magnetohydrodynamic (MHD)-waves. MHD-waves at their propagation gather information about the magnetosphere, ionosphere, and the ground. There are two applied aspects based on using the ULF electromagnetic oscillations. The first one is the ground-based diagnostics of the magnetosphere. This is an attempt to monitor in the real time the magnetosphere size, distance to the last closed field-lines, distribution of the cold plasma, etc. The second one is the deep electromagnetic sounding of the Earth. The basis for these studies is the capability of any electromagnetic wave to penetrate a conductor to a finite depth. The ULF-waves can reach the depth of a few hundred ...

Astronomy and culture

CERN Document Server

Hetherington, Edith

2009-01-01

While astronomy is a burgeoning science, with tremendous increases in knowledge every year, it also has a tremendous past, one that has altered humanity's understanding of our place in the universe. The impact of astronomy on culture - whether through myths and stories, or through challenges to the intellectual status quo - is incalculable. This volume in the Greenwood Guides to the Universe series examines how human cultures, in all regions and time periods, have tried to make sense of the wonders of the universe. Astronomy and Culture shows students how people throughout time have struggled

Electronic ground support equipment for the Cluster Electric Field and Wave Experiment

International Nuclear Information System (INIS)

Sten, T.A.

1992-10-01

In a collaboration between ESA and NASA, ionosphere plasma structures will be studied by four indentical space probes to be launched in 1995 from French Guiana. The Electric Field and Wave (EFW) experiment will be designed to measure electric field and density fluctations by means of four sensors, each deployed on a 50 meter wire boom. In order to perform comprehensive tests and calibrations of the EFW experiment, computer controlled electronic ground support equipment has been developed. This report describes the hardware of the equipment, produced and assembled at the University of Oslo. 15 figs

Radio astronomy

International Nuclear Information System (INIS)

Parijskij, Y.N.; Gossachinskij, I.V.; Zuckerman, B.; Khersonsky, V.K.; Pustilnik, S.; Robinson, B.J.

1976-01-01

A critical review of major developments and discoveries in the field of radioastronomy during the period 1973-1975 is presented. The report is presented under the following headings:(1) Continuum radiation from the Galaxy; (2) Neutral hydrogen, 21 cm (galactic and extragalactic) and recombination lines; (3) Radioastronomy investigations of interstellar molecules; (4) Extragalactic radio astronomy and (6) Development in radio astronomy instruments. (B.R.H.)

Searching for gravitational-wave signals emitted by eccentric compact binaries using a non-eccentric template bank: implications for ground-based detectors

Energy Technology Data Exchange (ETDEWEB)

Cokelaer, T; Pathak, D, E-mail: Thomas.Cokelaer@astro.cf.ac.u, E-mail: Devanka.Pathak@astro.cf.ac.u [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)

2009-02-21

Most of the inspiralling compact binaries are expected to be circularized by the time their gravitational-wave signals enter the frequency band of ground-based detectors such as LIGO or VIRGO. However, it is not excluded that some of these binaries might still possess a significant eccentricity at a few tens of hertz. Despite this possibility, current search pipelines-based on matched filtering techniques-consider only non-eccentric templates. The effect of such an approximation on the loss of signal-to-noise ratio (SNR) has been investigated by Martel and Poisson (1999 Phys. Rev. D 60 124008) in the context of initial LIGO detector. They ascertained that non-eccentric templates will be successful at detecting eccentric signals. We revisit their work by incorporating current and future ground-based detectors and precisely quantify the exact loss of SNR. In order to be more faithful to an actual search, we maximized the SNR over a template bank, whose minimal match is set to 95%. For initial LIGO detector, we claim that the initial eccentricity does not need to be taken into account in our searches for any system with total mass M element of [2-45]M{sub o-dot} if e{sub 0} approx< 0.05 because the loss of SNR (about 5%) is consistent with the discreteness of the template bank. Similarly, this statement is also true for systems with M element of [6-35]M{sub o-dot} and e{sub 0} approx< 0.10. However, by neglecting the eccentricity in our searches, significant loss of detection (larger than 10%) may arise as soon as e{sub 0} >= 0.05 for neutron-star binaries. We also provide exhaustive results for VIRGO, Advanced LIGO and Einstein Telescope detectors. It is worth noting that for Einstein Telescope, neutron star binaries with e{sub 0} >= 0.02 lead to a 10% loss of detection.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA.

Science.gov (United States)

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; Akutsu, T; Allen, B; Allocca, A; Altin, P A; Ananyeva, A; Anderson, S B; Anderson, W G; Ando, M; Appert, S; Arai, K; Araya, A; Araya, M C; Areeda, J S; Arnaud, N; Arun, K G; Asada, H; Ascenzi, S; Ashton, G; Aso, Y; Ast, M; Aston, S M; Astone, P; Atsuta, S; Aufmuth, P; Aulbert, C; Avila-Alvarez, A; Awai, K; Babak, S; Bacon, P; Bader, M K M; Baiotti, L; 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; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Baune, C; Bavigadda, V; Bazzan, M; Bécsy, B; Beer, C; Bejger, M; Belahcene, I; Belgin, M; Bell, A S; Berger, B K; Bergmann, G; Berry, C P L; Bersanetti, D; Bertolini, A; Betzwieser, J; Bhagwat, S; Bhandare, R; Bilenko, I A; Billingsley, G; Billman, C R; Birch, J; Birney, R; Birnholtz, O; Biscans, S; Bisht, A; Bitossi, M; Biwer, C; Bizouard, M A; Blackburn, J K; Blackman, J; Blair, C D; Blair, D G; Blair, R M; Bloemen, S; Bock, O; Boer, M; Bogaert, G; Bohe, A; 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; Broida, J E; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Brunett, S; Buchanan, C C; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cabero, M; Cadonati, L; Cagnoli, G; Cahillane, C; Calderón Bustillo, J; Callister, T A; Calloni, E; Camp, J B; Cannon, K C; Cao, H; 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; Chamberlin, S J; Chan, M; Chao, S; Charlton, P; Chassande-Mottin, E; Cheeseboro, B D; Chen, H Y; Chen, Y; Cheng, H-P; Chincarini, A; Chiummo, A; Chmiel, T; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, A J K; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Cocchieri, C; Coccia, E; Cohadon, P-F; Colla, A; Collette, C G; Cominsky, L; Constancio, M; Conti, L; Cooper, S J; Corbitt, T R; Cornish, N; Corsi, A; Cortese, S; Costa, C A; Coughlin, M W; Coughlin, S B; Coulon, J-P; Countryman, S T; Couvares, P; Covas, P B; Cowan, E E; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Creighton, J D E; Creighton, T D; Cripe, J; Crowder, S G; Cullen, T J; Cumming, A; Cunningham, L; Cuoco, E; Canton, T Dal; Danilishin, S L; D'Antonio, S; Danzmann, K; Dasgupta, A; Da Silva Costa, C F; Dattilo, V; Dave, I; Davier, M; Davies, G S; Davis, D; Daw, E J; Day, B; Day, R; De, S; 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; Devine, R C; Dhurandhar, S; Díaz, M C; Fiore, L Di; Giovanni, M Di; Girolamo, T Di; Lieto, A Di; Pace, S Di; Palma, I Di; Virgilio, A Di; Doctor, Z; Doi, K; Dolique, V; Donovan, F; Dooley, K L; Doravari, S; Dorrington, I; Douglas, R; Dovale Álvarez, M; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S E; Eda, K; Edo, T B; Edwards, M C; Effler, A; Eggenstein, H-B; Ehrens, P; Eichholz, J; Eikenberry, S S; Eisenstein, R A; Essick, R C; Etienne, Z; Etzel, T; Evans, M; Evans, T M; Everett, R; Factourovich, M; Fafone, V; Fair, H; Fairhurst, S; Fan, X; Farinon, S; Farr, B; Farr, W M; Fauchon-Jones, E J; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Fernández Galiana, A; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fiorucci, D; Fisher, R P; Flaminio, R; Fletcher, M; Fong, H; Forsyth, S S; Fournier, J-D; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Frey, V; Fries, E M; Fritschel, P; Frolov, V V; Fujii, Y; Fujimoto, M-K; 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; Hagiwara, A; 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; Hayama, K; Healy, J; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; 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Kirchhoff, R; Kissel, J S; Klein, B; Kleybolte, L; Klimenko, S; Koch, P; Koehlenbeck, S M; Kojima, Y; Kokeyama, K; Koley, S; Komori, K; Kondrashov, V; Kontos, A; Korobko, M; Korth, W Z; Kotake, K; Kowalska, I; Kozak, D B; Krämer, C; Kringel, V; Krishnan, B; Królak, A; Kuehn, G; Kumar, P; Kumar, Rahul; Kumar, Rakesh; Kuo, L; Kuroda, K; Kutynia, A; Kuwahara, Y; Lackey, B D; Landry, M; Lang, R N; Lange, J; Lantz, B; Lanza, R K; Lartaux-Vollard, A; Lasky, P D; Laxen, M; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, H W; Lee, K; Lehmann, J; Lenon, A; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Li, T G F; Libson, A; Littenberg, T B; Liu, J; Lockerbie, N A; Lombardi, A L; London, L T; Lord, J E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J D; Lousto, C O; Lovelace, G; Lück, H; Lundgren, A P; Lynch, R; Ma, Y; Macfoy, S; Machenschalk, B; MacInnis, M; Macleod, D M; Magaña-Sandoval, F; Majorana, E; Maksimovic, I; Malvezzi, V; 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2018-01-01

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

Science.gov (United States)

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S.; Klein, B.; Kleybolte, L.; Klimenko, S.; Koch, P.; Koehlenbeck, S. M.; Kojima, Y.; Kokeyama, K.; Koley, S.; Komori, K.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kotake, K.; Kowalska, I.; Kozak, D. B.; Krämer, C.; Kringel, V.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, P.; Kumar, Rahul; Kumar, Rakesh; Kuo, L.; Kuroda, K.; Kutynia, A.; Kuwahara, Y.; Lackey, B. D.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, H. W.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Liu, J.; Lockerbie, N. A.; Lombardi, A. L.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lück, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Mano, S.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marchio, M.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Matsumoto, N.; Matsushima, F.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGrath, C.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; 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.; Michimura, Y.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Miyakawa, O.; Miyamoto, A.; Miyamoto, T.; Miyoki, S.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morii, W.; Morisaki, S.; Moriwaki, Y.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muniz, E. A. M.; Murray, P. G.; Mytidis, A.; Nagano, S.; Nakamura, K.; Nakamura, T.; Nakano, H.; Nakano, Masaya; Nakano, Masayuki; Nakao, K.; Napier, K.; Nardecchia, I.; Narikawa, T.; Naticchioni, L.; Nelemans, G.; Nelson, T. J. N.; Neri, M.; Nery, M.; Neunzert, A.; Newport, J. M.; Newton, G.; Nguyen, T. T.; Ni, W.-T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohashi, M.; Ohishi, N.; Ohkawa, M.; Ohme, F.; Okutomi, K.; Oliver, M.; Ono, K.; Ono, Y.; Oohara, K.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, 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.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Peña Arellano, F. E.; Penn, S.; Perez, C. J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. 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.; Sago, N.; Saijo, M.; Saito, Y.; Sakai, K.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sandberg, V.; Sanders, J. R.; Sasaki, Y.; Sassolas, B.; Sathyaprakash, B. S.; Sato, S.; Sato, T.; 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.; Sekiguchi, T.; Sekiguchi, Y.; 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.; Shibata, M.; Shikano, Y.; Shimoda, T.; Shoda, 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.; Somiya, K.; 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.; Sugimoto, Y.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Suzuki, T.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Tagoshi, H.; Takada, S.; Takahashi, H.; Takahashi, R.; Takamori, A.; Talukder, D.; Tanaka, H.; Tanaka, K.; Tanaka, T.; Tanner, D. B.; Tápai, M.; Taracchini, A.; Tatsumi, D.; Taylor, R.; Telada, S.; 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.; Tomaru, T.; 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.; Tsubono, K.; Tsuzuki, T.; Turconi, M.; Tuyenbayev, D.; Uchiyama, T.; Uehara, T.; Ueki, S.; Ueno, K.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Ushiba, T.; 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 Putten, M. H. P. M.; 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.; Wakamatsu, T.; 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.; Yamamoto, K.; Yamamoto, T.; Yancey, C. C.; Yano, K.; Yap, M. J.; Yokoyama, J.; Yokozawa, T.; Yoon, T. H.; Yu, Hang; Yu, Haocun; Yuzurihara, H.; Yvert, M.; Zadrożny, A.; Zangrando, L.; Zanolin, M.; Zeidler, S.; 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.

2018-04-01

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-20 deg^2 requires at least three detectors of sensitivity within a factor of ˜ 2 of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

A waveguide finite element aided analysis of the wave field on a stationary tyre, not in contact with the ground

Science.gov (United States)

Sabiniarz, Patrick; Kropp, Wolfgang

2010-07-01

Although tyre/road noise has been a research subject for more than three decades, there is still no consensus in the literature as to which waves on a tyre are mainly responsible for the radiation of sound during rolling. Even the free vibrational behaviour of a stationary (non-rotating) tyre, not in contact with the ground, is still not well understood in the mid- and high-frequency ranges. Thus, gaining an improved understanding of this behaviour is a natural first step towards illuminating the question of which waves on a rolling tyre contribute to sound radiation. This is the topic of the present paper, in which a model based on the waveguide finite element method (WFEM) is used to study free wave propagation, on a stationary tyre, in the range 0-1500 Hz. In the low-frequency region (0-300 Hz), wave propagation is found to be rather straightforward, with two main wave-types present. Both have cross-section modes involving a nearly rigid motion of the belt. For higher frequencies (300-1500 Hz) the behaviour is more complex, including phenomena such as 'curve veering' and waves for which the phase speed and group speed have opposite signs. Wave-types identified in this region include (i) waves involving mainly sidewall deformation, (ii) belt bending waves, (iii) a wave with significant extensional deformation of the central belt region and (iv) a wave with a 'breathing' cross-section mode. The phase speed corresponding to found waves is computed and their radiation efficiency is discussed, assuming free-field conditions. In a future publication, the tyre model will be used in conjunction with a contact model and a radiation model to investigate the contribution of these waves to radiated sound during rolling.

Motivational Differences between MOOC and Undergraduate Astronomy Students

Science.gov (United States)

Formanek, Martin; Wenger, Matthew; Buxner, Sanlyn; Impey, Chris David

2018-01-01

It is vital for the instructors and designers of the Massive Open Online Courses (MOOCs) to understand the motivation of its users for enrolling in the class and their reasons to engage with the material. This is particularly important for MOOCs focusing on scientific topics such as our MOOC on Astronomy (Astronomy: Exploring time and space) whose audience is less motivated by a desire to advance their careers compared to other MOOCs. In order to learn more about the motivation of our learners we deployed in our Astronomy MOOC a survey based on the Science Motivation Questionnaire II developed by Glynn et. al (2011). We specifically asked for reasons to sign up for the course and the overall motivation and attitude towards astronomy and science courses. We compare results of 3360 participants of this survey with a similar instrument administered to 638 students in undergraduate Astronomy classes for non Astronomy majors at the University of Arizona. Our comparison not only looks at the demographic differences, but also at reasons for signing up for the course and scores in motivational categories such as self-determination, self-efficacy, grade motivation, career motivation, hobby motivation, social motivation, and intrinsic motivation showing, that these populations of learners are fundamentally different.

The Center for Astronomy Education (CAE) and Our NSF Funded CCLI Phase III Collaboration of Astronomy Teaching Scholars (CATS) Program: Updates to Our New Community-Based Model for Astronomy Education Research

Science.gov (United States)

Brissenden, Gina; Impey, C.; Prather, E. E.; Lee, K. M.; CATS

2010-01-01

The Center for Astronomy Education (CAE) has been devoted to improving teaching & learning in Astro 101 by creating research-validated curriculum & assessment instruments for use in Astro 101 & by providing Astro 101 instructors professional development opportunities to increase their pedagogical content knowledge & instructional skills at implementing these curricula & assessment materials. To create sustainability and further expand this work, CAE, in collaboration with other national leaders in astronomy education & research, developed the Collaboration of Astronomy Teaching Scholars (CATS) Program. The primary goals of CATS are to: 1) increase the number of Astro 101 instructors conducting fundamental research in astronomy education 2) increase the amount of research-validated curriculum & assessment instruments available for use in Astro 101 3) increase the number of people prepared to develop & conduct their own CAE Teaching Excellence Workshops In our second year we have concluded a national study assessing the contribution students’ personal characteristics make to student learning gains and the effectiveness of interactive learning strategies. We have results from our classroom research validation study on the use of the "ClassAction” electronic learning system. We have begun creation of an assessment instrument designed specifically for Astro 101 to evaluate the effectiveness of our instruction in improving students’ attitudes & beliefs about science, and which is being informed by several of our studies and community input. We have also begun field-testing of our Solar System Concept Inventory. Additionally research into students’ beliefs and reasoning difficulties on topics in Cosmology is underway. We acknowledge the NSF for funding under Award No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program.

Geospace Science from Ground-based Magnetometer Arrays: Advances in Sensors, Data Collection, and Data Integration

Science.gov (United States)

Mann, Ian; Chi, Peter

2016-07-01

Networks of ground-based magnetometers now provide the basis for the diagnosis of magnetic disturbances associated with solar wind-magnetosphere-ionosphere coupling on a truly global scale. Advances in sensor and digitisation technologies offer increases in sensitivity in fluxgate, induction coil, and new micro-sensor technologies - including the promise of hybrid sensors. Similarly, advances in remote connectivity provide the capacity for truly real-time monitoring of global dynamics at cadences sufficient for monitoring and in many cases resolving system level spatio-temporal ambiguities especially in combination with conjugate satellite measurements. A wide variety of the plasmaphysical processes active in driving geospace dynamics can be monitored based on the response of the electrical current system, including those associated with changes in global convection, magnetospheric substorms and nightside tail flows, as well as due to solar wind changes in both dynamic pressure and in response to rotations of the direction of the IMF. Significantly, any changes to the dynamical system must be communicated by the propagation of long-period Alfven and/or compressional waves. These wave populations hence provide diagnostics for not only the energy transport by the wave fields themselves, but also provide a mechanism for diagnosing the structure of the background plasma medium through which the waves propagate. Ultra-low frequency (ULF) waves are especially significant in offering a monitor for mass density profiles, often invisible to particle detectors because of their very low energy, through the application of a variety of magneto-seismology and cross-phase techniques. Renewed scientific interest in the plasma waves associated with near-Earth substorm dynamics, including magnetosphere-ionosphere coupling at substorm onset and their relation to magnetotail flows, as well the importance of global scale ultra-low frequency waves for the energisation, transport

On mean wind and turbulence profile measurements from ground-based wind lidars

DEFF Research Database (Denmark)

Mikkelsen, Torben

2009-01-01

Two types of wind lidar?s have become available for ground-based vertical mean wind and turbulence profiling. A continuous wave (CW) wind lidar, and a pulsed wind lidar. Although they both are build upon the same recent 1.55 μ telecom fibre technology, they possess fundamental differences between...... their temporal and spatial resolution capabilities. A literature review of the two lidar systems spatial and temporal resolution characteristics will be presented, and the implication for the two lidar types vertical profile measurements of mean wind and turbulence in the lower atmospheric boundary layer...

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar; Thingbaijam, Kiran Kumar; Adhikari, M. D.; Nayak, Avinash; Devaraj, N.; Ghosh, Soumalya K.; Mahajan, Arun K.

2013-01-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Topographic gradient based site characterization in India complemented by strong ground-motion spectral attributes

KAUST Repository

Nath, Sankar Kumar

2013-12-01

We appraise topographic-gradient approach for site classification that employs correlations between 30. m column averaged shear-wave velocity and topographic gradients. Assessments based on site classifications reported from cities across India indicate that the approach is reasonably viable at regional level. Additionally, we experiment three techniques for site classification based on strong ground-motion recordings, namely Horizontal-to-Vertical Spectral Ratio (HVSR), Response Spectra Shape (RSS), and Horizontal-to-Vertical Response Spectral Ratio (HVRSR) at the strong motion stations located across the Himalayas and northeast India. Statistical tests on the results indicate that these three techniques broadly differentiate soil and rock sites while RSS and HVRSR yield better signatures. The results also support the implemented site classification in the light of strong ground-motion spectral attributes observed in different parts of the globe. © 2013 Elsevier Ltd.

Infrasonic induced ground motions

Science.gov (United States)

Lin, Ting-Li

On January 28, 2004, the CERI seismic network recorded seismic signals generated by an unknown source. Our conclusion is that the acoustic waves were initiated by an explosive source near the ground surface. The meteorological temperature and effective sound speed profiles suggested existence of an efficient near-surface waveguide that allowed the acoustic disturbance to propagate to large distances. An explosion occurring in an area of forest and farms would have limited the number of eyewitnesses. Resolution of the source might be possible by experiment or by detailed analysis of the ground motion data. A seismo-acoustic array was built to investigate thunder-induced ground motions. Two thunder events with similar N-wave waveforms but different horizontal slownesses are chosen to evaluate the credibility of using thunder as a seismic source. These impulsive acoustic waves excited P and S reverberations in the near surface that depend on both the incident wave horizontal slowness and the velocity structure in the upper 30 meters. Nineteen thunder events were chosen to further investigate the seismo-acoustic coupling. The consistent incident slowness differences between acoustic pressure and ground motions suggest that ground reverberations were first initiated somewhat away from the array. Acoustic and seismic signals were used to generate the time-domain transfer function through the deconvolution technique. Possible non-linear interaction for acoustic propagation into the soil at the surface was observed. The reverse radial initial motions suggest a low Poisson's ratio for the near-surface layer. The acoustic-to-seismic transfer functions show a consistent reverberation series of the Rayleigh wave type, which has a systematic dispersion relation to incident slownesses inferred from the seismic ground velocity. Air-coupled Rayleigh wave dispersion was used to quantitatively constrain the near-surface site structure with constraints afforded by near-surface body

WAVE: Interactive Wave-based Sound Propagation for Virtual Environments.

Science.gov (United States)

Mehra, Ravish; Rungta, Atul; Golas, Abhinav; Ming Lin; Manocha, Dinesh

2015-04-01

We present an interactive wave-based sound propagation system that generates accurate, realistic sound in virtual environments for dynamic (moving) sources and listeners. We propose a novel algorithm to accurately solve the wave equation for dynamic sources and listeners using a combination of precomputation techniques and GPU-based runtime evaluation. Our system can handle large environments typically used in VR applications, compute spatial sound corresponding to listener's motion (including head tracking) and handle both omnidirectional and directional sources, all at interactive rates. As compared to prior wave-based techniques applied to large scenes with moving sources, we observe significant improvement in runtime memory. The overall sound-propagation and rendering system has been integrated with the Half-Life 2 game engine, Oculus-Rift head-mounted display, and the Xbox game controller to enable users to experience high-quality acoustic effects (e.g., amplification, diffraction low-passing, high-order scattering) and spatial audio, based on their interactions in the VR application. We provide the results of preliminary user evaluations, conducted to study the impact of wave-based acoustic effects and spatial audio on users' navigation performance in virtual environments.

Women in Astronomy Workshop Report

OpenAIRE

Brough, Sarah; Bauer, Amanda E.; Brooks, Kate; Hopkins, Andrew; Maddison, Sarah

2011-01-01

Here we report on the Women in Astronomy Workshop (http://asawomeninastronomy.org/meetings/wia2011/), which was held on 13 May 2011 in Sydney, Australia. The workshop was organised by the Astronomical Society of Australia's Chapter on Women in Astronomy, to discuss some of the issues that face women in astronomy and make recommendations to help support the success of women in Australian astronomy but came to broader conclusions that have value for the whole astronomical community. The worksho...

The purpose of astronomy

OpenAIRE

Davoust, Emmanuel

1995-01-01

This is a presentation of the purpose of astronomy in the context of modern society. After exposing two misconceptions about astronomy, I detail its role in five domains, certified knowledge, incorporated abilities, innovations, collective goods, and popular science; with each domain is associated an institution, an incentive, and a method of evaluation. Finally, I point out the role of astronomy as a source of inspiration in other fields than science.

History of Astronomy in Portugal: Theories, Institutions and Practices

Science.gov (United States)

Saraiva, Luis

2014-01-01

In Portugal, throughout its history, astronomy was developed in the context of the mathematical sciences. During the times of Portugal's Maritime Discoveries, astronomical navigation was based on spherical trigonometry, and therefore it was the mathematicians who taught astronomy to the pilots. During the 17th century, basic notions of astronomy were taught in mathematical courses in the University and in the main Jesuit colleges. This tradition continued in the 18th century, so it is no wonder that one of the most influent Portuguese astronomers during this period was the mathematician José Monteiro da Rocha. During the 19th century the new centres of science teaching, as the Polytechnic School in Lisbon, or the Polytechnic Academy in Oporto, developed astronomy teaching and research in the context of the mathematics subjects. The inheritors of these 19th century institutions, respectively the Faculties of Sciences of Lisbon and Oporto, upheld this tradition until the final decades of 20th century and continued to consider astronomy as a subject to be taught in their mathematics departments. This Meeting aims at outlining several perspectives on the history of astronomy in Portugal, particularly analysing its ties with mathematical sciences and astronomy applications. The Meeting is organised by the Museum of Science of the University of Lisbon (MCUL) with CMAF, CMUC, CMUP and the CIUHCT, and is included in CIM events. It is integrated in the commemorations of the International Year of Astronomy (IYA2009).

Inuit Astronomy

Science.gov (United States)

MacDonald, John

Inuit live mainly in the treeless Arctic regions of North America, Greenland, and parts of northeastern Siberia. Their cosmology, based on shamanistic belief, constructed a view of the sky and its contents distinctively suited to their spiritual and pragmatic needs. Their astronomy, particularly for those groups living far above the Arctic Circle, reflects the unique appearance of the celestial sphere at high northerly latitudes, demonstrated most noticeably in the annual disappearance of the sun during midwinter months.

Stamping through astronomy

CERN Document Server

Dicati, Renato

2013-01-01

Stamps and other postal documents are an attractive vehicle for presenting astronomy and its development. Written with expertise and great enthusiasm, this unique book offers a historical and philatelic survey of astronomy and some related topics on space exploration. It contains more than 1300 color reproductions of stamps relating to the history of astronomy, ranging from the earliest observations of the sky to modern research conducted with satellites and space probes. Featured are the astronomers and astrophysicists who contributed to this marvelous story – not only Ptolemy, Copernicus, Kepler, Newton, Herschel, and Einstein but also hundreds of other minor protagonists who played an important role in the development of this, the most ancient yet the most modern of all the sciences. The book also examines in depth the diverse areas which have contributed to the history of astronomy, including the instrumentation, the theories, and the observations. Many stamps illustrate the beauty and the mystery of ce...

Improving Astronomy Achievement and Attitude through Astronomy Summer Project: A Design, Implementation and Assessment

Science.gov (United States)

Türk, Cumhur; Kalkan, Hüseyin; Iskeleli', Nazan Ocak; Kiroglu, Kasim

2016-01-01

The purpose of this study is to examine the effects of an astronomy summer project implemented in different learning activities on elementary school students, pre-service elementary teachers and in-service teachers' astronomy achievement and their attitudes to astronomy field. This study is the result of a five-day, three-stage, science school,…

The Japanese space gravitational wave antenna-DECIGO

International Nuclear Information System (INIS)

Kawamura, Seiji; Nakamura, Takashi; Ando, Masaki

2006-01-01

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. It aims at detecting various kinds of gravitational waves between 1 mHz and 100 Hz frequently enough to open a new window of observation for gravitational wave astronomy. The pre-conceptual design of DECIGO consists of three drag-free satellites, 1000 km apart from each other, whose relative displacements are measured by a Fabry-Perot Michelson interferometer. We plan to launch DECIGO in 2024 after a long and intense development phase, including two pathfinder missions for verification of required technologies

The Center for Astronomy Education (CAE) Ushers in a New Community-Based Model for Astronomy Education Research with the NSF Funded CCLI Phase III Collaboration of Astronomy Teaching Scholars (CATS) Program

Science.gov (United States)

Brissenden, Gina; Impey, C.; Prather, E.; Lee, K.; Duncan, D.

2009-01-01

The Center for Astronomy Education (CAE) has been devoted to improving teaching & learning in Astro 101 by creating research-validated curriculum & assessment instruments for use in Astro 101 & by providing Astro 101 instructors professional development opportunities to increase their pedagogical content knowledge & instructional skills at implementing these curricula & assessment materials. To create sustainability and further expand this work, CAE, in collaboration with other national leaders in astronomy education & research, developed the Collaboration of Astronomy Teaching Scholars (CATS) Program. The primary goals of CATS are to: 1) increase the number of Astro 101 instructors conducting fundamental research in astronomy education 2) increase the amount of research-validated curriculum & assessment instruments available for use in Astro 101 3) increase the number of people prepared to develop & conduct their own CAE Teaching Excellence Workshops In our first year we have concluded a national study assessing the teaching & learning of Astro 101 & the effect of interactive instruction. We have begun the initial analysis of the demographics data of this study. We have begun a classroom research validation study on the use of the "ClassAction” electronic learning system. We have begun to analyze data from two different studies on students’ attitudes & understanding of science to inform the creation of an assessment instrument designed specifically for Astro 101 to evaluate the effectiveness of our instruction in improving students’ attitudes & beliefs about science. We have also begun the development of a Solar System Concept Inventory. Additionally the development of the Solar System Concept Inventory and research into students’ beliefs and reasoning difficulties on topics in Cosmology are well underway. We acknowledge the NSF for funding under Award No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program.

Synthesis of High-Frequency Ground Motion Using Information Extracted from Low-Frequency Ground Motion

Science.gov (United States)

Iwaki, A.; Fujiwara, H.

2012-12-01

Broadband ground motion computations of scenario earthquakes are often based on hybrid methods that are the combinations of deterministic approach in lower frequency band and stochastic approach in higher frequency band. Typical computation methods for low-frequency and high-frequency (LF and HF, respectively) ground motions are the numerical simulations, such as finite-difference and finite-element methods based on three-dimensional velocity structure model, and the stochastic Green's function method, respectively. In such hybrid methods, LF and HF wave fields are generated through two different methods that are completely independent of each other, and are combined at the matching frequency. However, LF and HF wave fields are essentially not independent as long as they are from the same event. In this study, we focus on the relation among acceleration envelopes at different frequency bands, and attempt to synthesize HF ground motion using the information extracted from LF ground motion, aiming to propose a new method for broad-band strong motion prediction. Our study area is Kanto area, Japan. We use the K-NET and KiK-net surface acceleration data and compute RMS envelope at four frequency bands: 0.5-1.0 Hz, 1.0-2.0 Hz, 2.0-4.0 Hz, .0-8.0 Hz, and 8.0-16.0 Hz. Taking the ratio of the envelopes of adjacent bands, we find that the envelope ratios have stable shapes at each site. The empirical envelope-ratio characteristics are combined with low-frequency envelope of the target earthquake to synthesize HF ground motion. We have applied the method to M5-class earthquakes and a M7 target earthquake that occurred in the vicinity of Kanto area, and successfully reproduced the observed HF ground motion of the target earthquake. The method can be applied to a broad band ground motion simulation for a scenario earthquake by combining numerically-computed low-frequency (~1 Hz) ground motion with the empirical envelope ratio characteristics to generate broadband ground motion

Localization and Broadband Follow-up of the Gravitational-wave Transient GW150914

Science.gov (United States)

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.; Barthelmy, S.; 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. 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C.; Casentini, C.; Caudill, S.; Cavagliá, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. C.; 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., Jr.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; 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.; Dereli, H.; Dergachev, V.; DeRosa, R. T.; De Rosa, R.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; 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. 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D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Haris, K.; 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.; Kalaghatgi, C. V.; Kalogera, V.; 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, C.; Kim, J.; Kim, K.; Kim, N.; Kim, N.; 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.; 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.; 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.; 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.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, 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, A.; Mukherjee, D.; Mukherjee, S.; Mukund, 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, R. J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Ottens, R. 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B.; Frieman, J.; Fryer, C. L.; Gaztanaga, E.; Gerdes, D. W.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Herner, K.; Honscheid, K.; James, D. J.; Johnson, M. D.; Johnson, M. W. G.; Karliner, I.; Kasen, D.; Kent, S.; Kessler, R.; Kim, A. G.; Kind, M. C.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Li, T. S.; Lima, M.; Lin, H.; Maia, M. A. G.; Margutti, R.; Marriner, J.; Martini, P.; Matheson, T.; Melchior, P.; Metzger, B. D.; Miller, C. J.; Miquel, R.; Neilsen, E.; Nichol, R. C.; Nord, B.; Nugent, P.; Ogando, R.; Petravick, D.; Plazas, A. A.; Quataert, E.; Roe, N.; Romer, A. K.; Roodman, A.; Rosell, A. C.; Rykoff, E. S.; Sako, M.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Scolnic, D.; Sevilla-Noarbe, I.; Sheldon, E.; Smith, N.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Stebbins, A.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Thomas, D.; Thomas, R. C.; Tucker, D. L.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Wester, W.; Yanny, B.; Zhang, Y.; Zuntz, J.; Dark Energy Survey Collaboration; Dark Energy Camera GW-EM Collaboration; Connaughton, V.; Burns, E.; Goldstein, A.; Briggs, M. S.; Zhang, B.-B.; Hui, C. M.; Jenke, P.; Wilson-Hodge, C. A.; Bhat, P. N.; Bissaldi, E.; Cleveland, W.; Fitzpatrick, G.; Giles, M. M.; Gibby, M. H.; Greiner, J.; von Kienlin, A.; Kippen, R. M.; McBreen, S.; Mailyan, B.; Meegan, C. A.; Paciesas, W. S.; Preece, R. D.; Roberts, O.; Sparke, L.; Stanbro, M.; Toelge, K.; Veres, P.; Yu, H.-F.; Blackburn, L.; Fermi GBM Collaboration; Ackermann, M.; Ajello, M.; Albert, A.; Anderson, B.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bonino, R.; Bottacini, E.; Brandt, T. J.; Bruel, P.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caragiulo, M.; Caraveo, P. A.; Cavazzuti, E.; Charles, E.; Chekhtman, A.; Chiang, J.; Chiaro, G.; Ciprini, S.; Cohen-Tanugi, J.; Cominsky, L. R.; Costanza, F.; Cuoco, A.; D'Ammando, F.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Lalla, N.; Di Mauro, M.; Di Venere, L.; Domínguez, A.; Drell, P. S.; Dubois, R.; Favuzzi, C.; Ferrara, E. C.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Green, D.; Grenier, I. A.; Grove, J. E.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Jogler, T.; Jóhannesson, G.; Johnson, A. S.; Kensei, S.; Kocevski, D.; Kuss, M.; La Mura, G.; Larsson, S.; Latronico, L.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Magill, J.; Maldera, S.; Manfreda, A.; Marelli, M.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Meyer, M.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Moretti, E.; Morselli, A.; Moskalenko, I. V.; Negro, M.; Nuss, E.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzaque, S.; Reimer, A.; Reimer, O.; Salvetti, D.; Saz Parkinson, P. M.; Sgrò, C.; Simone, D.; Siskind, E. J.; Spada, F.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Troja, E.; Uchiyama, Y.; Venters, T. M.; Vianello, G.; Wood, K. S.; Wood, M.; Zhu, S.; Zimmer, S.; Fermi LAT Collaboration; Brocato, E.; Cappellaro, E.; Covino, S.; Grado, A.; Nicastro, L.; Palazzi, E.; Pian, E.; Amati, L.; Antonelli, L. A.; Capaccioli, M.; D'Avanzo, P.; D'Elia, V.; Getman, F.; Giuffrida, G.; Iannicola, G.; Limatola, L.; Lisi, M.; Marinoni, S.; Marrese, P.; Melandri, A.; Piranomonte, S.; Possenti, A.; Pulone, L.; Rossi, A.; Stamerra, A.; Stella, L.; Testa, V.; Tomasella, L.; Yang, S.; GRAvitational Wave Inaf TeAm (GRAWITA); Bazzano, A.; Bozzo, E.; Brandt, S.; Courvoisier, T. J.-L.; Ferrigno, C.; Hanlon, L.; Kuulkers, E.; Laurent, P.; Mereghetti, S.; Roques, J. P.; Savchenko, V.; Ubertini, P.; INTEGRAL Collaboration; Kasliwal, M. M.; Singer, L. P.; Cao, Y.; Duggan, G.; Kulkarni, S. R.; Bhalerao, V.; Miller, A. A.; Barlow, T.; Bellm, E.; Manulis, I.; Rana, J.; Laher, R.; Masci, F.; Surace, J.; Rebbapragada, U.; Cook, D.; Van Sistine, A.; Sesar, B.; Perley, D.; Ferreti, R.; Prince, T.; Kendrick, R.; Horesh, A.; Intermediate Palomar Transient Factory (iPTF Collaboration); Hurley, K.; Golenetskii, S. V.; Aptekar, R. L.; Frederiks, D. D.; Svinkin, D. S.; Rau, A.; von Kienlin, A.; Zhang, X.; Smith, D. M.; Cline, T.; Krimm, H.; InterPlanetary Network; Abe, F.; Doi, M.; Fujisawa, K.; Kawabata, K. S.; Morokuma, T.; Motohara, K.; Tanaka, M.; Ohta, K.; Yanagisawa, K.; Yoshida, M.; J-GEM Collaboration; Baltay, C.; Rabinowitz, D.; Ellman, N.; Rostami, S.; La Silla-QUEST Survey; Bersier, D. F.; Bode, M. F.; Collins, C. A.; Copperwheat, C. M.; Darnley, M. J.; Galloway, D. K.; Gomboc, A.; Kobayashi, S.; Mazzali, P.; Mundell, C. G.; Piascik, A. S.; Pollacco, Don; Steele, I. A.; Ulaczyk, K.; Liverpool Telescope Collaboration; Broderick, J. W.; Fender, R. P.; Jonker, P. G.; Rowlinson, A.; Stappers, B. W.; Wijers, R. A. M. J.; Low Frequency Array (LOFAR Collaboration); Lipunov, V.; Gorbovskoy, E.; Tyurina, N.; Kornilov, V.; Balanutsa, P.; Kuznetsov, A.; Buckley, D.; Rebolo, R.; Serra-Ricart, M.; Israelian, G.; Budnev, N. M.; Gress, O.; Ivanov, K.; Poleshuk, V.; Tlatov, A.; Yurkov, V.; MASTER Collaboration; Kawai, N.; Serino, M.; Negoro, H.; Nakahira, S.; Mihara, T.; Tomida, H.; Ueno, S.; Tsunemi, H.; Matsuoka, M.; MAXI Collaboration; Croft, S.; Feng, L.; Franzen, T. M. O.; Gaensler, B. M.; Johnston-Hollitt, M.; Kaplan, D. L.; Morales, M. F.; Tingay, S. J.; Wayth, R. B.; Williams, A.; Murchison Wide-field Array (MWA Collaboration); Smartt, S. J.; Chambers, K. C.; Smith, K. W.; Huber, M. E.; Young, D. R.; Wright, D. E.; Schultz, A.; Denneau, L.; Flewelling, H.; Magnier, E. A.; Primak, N.; Rest, A.; Sherstyuk, A.; Stalder, B.; Stubbs, C. W.; Tonry, J.; Waters, C.; Willman, M.; Pan-STARRS Collaboration; Olivares E., F.; Campbell, H.; Kotak, R.; Sollerman, J.; Smith, M.; Dennefeld, M.; Anderson, J. P.; Botticella, M. T.; Chen, T.-W.; Della Valle, M.; Elias-Rosa, N.; Fraser, M.; Inserra, C.; Kankare, E.; Kupfer, T.; Harmanen, J.; Galbany, L.; Le Guillou, L.; Lyman, J. D.; Maguire, K.; Mitra, A.; Nicholl, M.; Razza, A.; Terreran, G.; Valenti, S.; Gal-Yam, A.; PESSTO Collaboration; Ćwiek, A.; Ćwiok, M.; Mankiewicz, L.; Opiela, R.; Zaremba, M.; Żarnecki, A. F.; Pi of Sky Collaboration; Onken, C. A.; Scalzo, R. A.; Schmidt, B. P.; Wolf, C.; Yuan, F.; SkyMapper Collaboration; Evans, P. A.; Kennea, J. A.; Burrows, D. N.; Campana, S.; Cenko, S. B.; Giommi, P.; Marshall, F. E.; Nousek, J.; O'Brien, P.; Osborne, J. P.; Palmer, D.; Perri, M.; Siegel, M.; Tagliaferri, G.; Swift Collaboration; Klotz, A.; Turpin, D.; Laugier, R.; TAROT Collaboration; Zadko Collaboration; Algerian National Observatory Collaboration; C2PU Collaboration; Beroiz, M.; Peñuela, T.; Macri, L. M.; Oelkers, R. J.; Lambas, D. G.; Vrech, R.; Cabral, J.; Colazo, C.; Dominguez, M.; Sanchez, B.; Gurovich, S.; Lares, M.; Marshall, J. L.; DePoy, D. L.; Padilla, N.; Pereyra, N. A.; Benacquista, M.; TOROS Collaboration; Tanvir, N. R.; Wiersema, K.; Levan, A. J.; Steeghs, D.; Hjorth, J.; Fynbo, J. P. U.; Malesani, D.; Milvang-Jensen, B.; Watson, D.; Irwin, M.; Fernandez, C. G.; McMahon, R. G.; Banerji, M.; Gonzalez-Solares, E.; Schulze, S.; de Ugarte Postigo, A.; Thoene, C. C.; Cano, Z.; Rosswog, S.; VISTA Collaboration

2016-07-01

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams.

LOCALIZATION AND BROADBAND FOLLOW-UP OF THE GRAVITATIONAL-WAVE TRANSIENT GW150914

Energy Technology Data Exchange (ETDEWEB)

Abbott, B. P.; Abbott, R.; Abernathy, M. R.; Adhikari, R. X. [LIGO, California Institute of Technology, Pasadena, CA 91125 (United States); Abbott, T. D. [Louisiana State University, Baton Rouge, LA 70803 (United States); Acernese, F.; Addesso, P. [Università di Salerno, Fisciano, I-84084 Salerno (Italy); Ackley, K. [University of Florida, Gainesville, FL 32611 (United States); Adams, C. [LIGO Livingston Observatory, Livingston, LA 70754 (United States); Adams, T. [Laboratoire d’Annecy-le-Vieux de Physique des Particules (LAPP), Université Savoie Mont Blanc, CNRS/IN2P3, F-74941 Annecy-le-Vieux (France); Adya, V. B.; Affeldt, C.; Allen, B. [Albert-Einstein-Institut, Max-Planck-Institut für Gravitationsphysik, D-30167 Hannover (Germany); Agathos, M.; Agatsuma, K. [Nikhef, Science Park, 1098 XG Amsterdam (Netherlands); Aggarwal, N. [LIGO, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Aguiar, O. D. [Instituto Nacional de Pesquisas Espaciais, 12227-010 São José dos Campos, SP (Brazil); Aiello, L. [INFN, Gran Sasso Science Institute, I-67100 L’Aquila (Italy); Ain, A. [Inter-University Centre for Astronomy and Astrophysics, Pune 411007 (India); Ajith, P., E-mail: lsc-spokesperson@ligo.org, E-mail: virgo-spokesperson@ego-gw.eu, E-mail: Julie.E.McEnery@nasa.gov [International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bangalore 560012 (India); Collaboration: LIGO Scientific Collaboration and the Virgo Collaboration; Australian Square Kilometer Array Pathfinder (ASKAP) Collaboration; BOOTES Collaboration; Dark Energy Survey and the Dark Energy Camera GW-EM Collaborations; Fermi GBM Collaboration; Fermi LAT Collaboration; GRAvitational Wave Inaf TeAm (GRAWITA); INTEGRAL Collaboration; Intermediate Palomar Transient Factory (iPTF) Collaboration; InterPlanetary Network; J-GEM Collaboration; La Silla–QUEST Survey; Liverpool Telescope Collaboration; Low Frequency Array (LOFAR) Collaboration; MASTER Collaboration; MAXI Collaboration; Murchison Wide-field Array (MWA) Collaboration; Pan-STARRS Collaboration; PESSTO Collaboration; Pi of the Sky Collaboration; SkyMapper Collaboration; Swift Collaboration; TAROT, Zadko, Algerian National Observatory, and C2PU Collaboration; TOROS Collaboration; VISTA Collaboration; and others

2016-07-20

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams.

LOCALIZATION AND BROADBAND FOLLOW-UP OF THE GRAVITATIONAL-WAVE TRANSIENT GW150914

International Nuclear Information System (INIS)

Abbott, B. P.; Abbott, R.; Abernathy, M. R.; Adhikari, R. X.; Abbott, T. D.; Acernese, F.; Addesso, P.; Ackley, K.; Adams, C.; Adams, T.; Adya, V. B.; Affeldt, C.; Allen, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.

2016-01-01

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams.

Preparing GEO 600 for gravitational wave astronomy-a status report

International Nuclear Information System (INIS)

Hewitson, M

2005-01-01

A number of gravitational wave detectors throughout the world are currently moving from the final stages of commissioning to a more continuous observational mode. Together, these detectors form a global network which will search for gravitational waves from various astrophysical sources, such as continuous wave signals from rotating neutron stars, transient signals from, for example, inspiralling compact objects and supernovae explosions, and stochastic gravitational wave signals from the early universe. GEO 600 is a long baseline laser-interferometric gravitational wave detector which employs advanced optical and suspension techniques to reach its design sensitivity. Almost all of the major installation work at GEO 600 is already completed and the detector is currently being commissioned to prepare it for extended observation periods. The commissioning process involves many activities in the areas of noise reduction, calibration, operational stability and characterization. This report highlights some of the major commissioning steps that have contributed to the increase in sensitivity of the instrument over the period from December 2003 to December 2004. In addition, recent extensions to the on-line calibration scheme used in GEO 600 are briefly discussed

Space-Based Astronomy: An Educator Guide with Activities for Science, Mathematics, and Technology Education

Science.gov (United States)

Vogt, Gregory L.

2001-01-01

If you go to the country, far from city lights, you can see about 3,000 stars on a clear night. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30 times, the number of stars you can see increases to the tens of thousands. With a medium-sized telescope with a light-collecting mirror 30 centimeters in diameter, you can see hundreds of thousands of stars. With a large observatory telescope, millions of stars become visible. This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy--astronomical observations made from outer space. It is not intended to serve as a curriculum. Instead, teachers should select activities from this guide that support and extend existing study. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. It tells, rather, the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. Teachers are encouraged to adapt these activities for the particular needs of their students. When selected activities from this guide are used in conjunction with traditional astronomy curricula, students benefit from a more complete experience.

Astronomy in Iraq

Science.gov (United States)

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

Ground-Wave Propagation Effects on Transmission Lines through Error Images

Directory of Open Access Journals (Sweden)

Uribe-Campos Felipe Alejandro

2014-07-01

Full Text Available Electromagnetic transient calculation of overhead transmission lines is strongly influenced by the natural resistivity of the ground. This varies from 1-10K (Ω·m depending on several media factors and on the physical composition of the ground. The accuracy on the calculation of a system transient response depends in part in the ground return model, which should consider the line geometry, the electrical resistivity and the frequency dependence of the power source. Up to date, there are only a few reports on the specialized literature about analyzing the effects produced by the presence of an imperfectly conducting ground of transmission lines in a transient state. A broad range analysis of three of the most often used ground-return models for calculating electromagnetic transients of overhead transmission lines is performed in this paper. The behavior of modal propagation in ground is analyzed here into effects of first and second order. Finally, a numerical tool based on relative error images is proposed in this paper as an aid for the analyst engineer to estimate the incurred error by using approximate ground-return models when calculating transients of overhead transmission lines.

Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

International Nuclear Information System (INIS)

Chiara, P.; Morelli, A.

2010-01-01

The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements.Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken.This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

Science.gov (United States)

Chiara, P.; Morelli, A.

2010-05-01

The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements. Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken. This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

Astronomy in Everyday Life

Science.gov (United States)

Rosenberg, M.; Bladon, G.; Russo, P.; Christensen, L. L.

2014-01-01

For a long time astronomers and other scientists believed that the importance of their work was evident to society. But in these difficult days of financial austerity, even the most obvious benefits of science have to undergo careful scrutiny. So, now more than ever is the time to highlight the importance of astronomy as a field in terms of its contributions to our technology, our mind sets and our lives. Here we will outline both the tangible and intangible reasons why astronomy is an important part of society. Whilst considerable attention will be given to technology and knowledge transfer from astronomy, perhaps the most important contribution outlined is the awareness that astronomy gives us of the vastness of the Universe and our place within it.

Multi-Messenger Astronomy and Dark Matter

Science.gov (United States)

Bergström, Lars

This chapter presents the elaborated lecture notes on Multi-Messenger Astronomy and Dark Matter given by Lars Bergström at the 40th Saas-Fee Advanced Course on "Astrophysics at Very High Energies". One of the main problems of astrophysics and astro-particle physics is that the nature of dark matter remains unsolved. There are basically three complementary approaches to try to solve this problem. One is the detection of new particles with accelerators, the second is the observation of various types of messengers from radio waves to gamma-ray photons and neutrinos, and the third is the use of ingenious experiments for direct detection of dark matter particles. After giving an introduction to the particle universe, the author discusses the relic density of particles, basic cross sections for neutrinos and gamma-rays, supersymmetric dark matter, detection methods for neutralino dark matter, particular dark matter candidates, the status of dark matter detection, a detailled calculation on an hypothetical "Saas-Fee Wimp", primordial black holes, and gravitational waves.

Music Inspired by Astronomy: A Selected Listing for the International Year of Astronomy

Science.gov (United States)

Fraknoi, A.

2008-11-01

Part of the aim of the International Year of Astronomy is to show the connections between astronomy and other areas of human culture. Such connections are easily found in music, where astronomical ideas have found a wide range of expression. This is not a comprehensive listing, but a sampling of some of the pieces that are available on CD's, and that may be of particular interest to educators and astronomy enthusiasts. To qualify for the list, a piece (or the composer's vision for it) has to include some real science and not just an astronomical term in the title or in a few lyrics. For example, we do not list The Planets, by Gustav Holst, since it treats the astrological view of the planets. And we regret that Philip Glass' opera Galileo is not available on CD and therefore cannot be listed. Nor do we include the thousands of popular songs that use the moon or the stars for an easy rhyme or a quick romantic image. And, while many jazz pieces have astronomy in the title, it is often hard to know just how the piece and the astronomy go together; so we've sadly omitted jazz too. For those with old-fashioned ears, like the author, we note that no warranty is made that all these pieces are easy to listen to, but each takes some key idea from astronomy and makes music out of it. A more comprehensive discussion can be found in my article in Astronomy Education Review: http://aer.noao.edu/cgi-bin/article.pl?id=193

MULTI-MESSENGER ASTRONOMY OF GRAVITATIONAL-WAVE SOURCES WITH FLEXIBLE WIDE-AREA RADIO TRANSIENT SURVEYS

Energy Technology Data Exchange (ETDEWEB)

Yancey, Cregg C.; Shawhan, Peter [Department of Physics, University of Maryland, College Park, MD 20742 (United States); Bear, Brandon E.; Akukwe, Bernadine; Simonetti, John H.; Tsai, Jr-Wei [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Chen, Kevin [Department of Physics, The College of New Jersey, Ewing, NJ 08628 (United States); Dowell, Jayce; Obenberger, Kenneth; Taylor, Gregory B. [Department of Physics and Astronomy, University of New Mexico, Albuquerque NM, 87131 (United States); Gough, Jonathan D. [Department of Chemistry, Lehman College, Bronx, NY 10468 (United States); Kanner, Jonah [LIGO-California Institute of Technology, Pasadena, California CA 91125 (United States); Kavic, Michael [Department of Physics, Long Island University, Brooklyn, NY 11201 (United States)

2015-10-20

We explore opportunities for multi-messenger astronomy using gravitational waves (GWs) and prompt, transient low-frequency radio emission to study highly energetic astrophysical events. We review the literature on possible sources of correlated emission of GWs and radio transients, highlighting proposed mechanisms that lead to a short-duration, high-flux radio pulse originating from the merger of two neutron stars or from a superconducting cosmic string cusp. We discuss the detection prospects for each of these mechanisms by low-frequency dipole array instruments such as LWA1, the Low Frequency Array and the Murchison Widefield Array. We find that a broad range of models may be tested by searching for radio pulses that, when de-dispersed, are temporally and spatially coincident with a LIGO/Virgo GW trigger within a ∼30 s time window and ∼200–500 deg{sup 2} sky region. We consider various possible observing strategies and discuss their advantages and disadvantages. Uniquely, for low-frequency radio arrays, dispersion can delay the radio pulse until after low-latency GW data analysis has identified and reported an event candidate, enabling a prompt radio signal to be captured by a deliberately targeted beam. If neutron star mergers do have detectable prompt radio emissions, a coincident search with the GW detector network and low-frequency radio arrays could increase the LIGO/Virgo effective search volume by up to a factor of ∼2. For some models, we also map the parameter space that may be constrained by non-detections.

Astronomy Explained

Science.gov (United States)

North, Gerald

Every year large numbers of people take up the study of astronomy, mostly at amateur level. There are plenty of elementary books on the market, full of colourful photographs, but lacking in proper explanations of how and why things are as they are. Many people eventually wish to go beyond the 'coffee-table book' stage and study this fascinating subject in greater depth. This book is written for them. In addition, many people sit for public examinations in this subject each year and this book is also intended to be of use to them. All the topics from the GCSE syllabus are covered here, with sample questions at the end of each chapter. Astronomy Explained provides a comprehensive treatment of the subject in more depth than is usually found in elementary works, and will be of interest to both amateur astronomers and students of astronomy.

Astronomy on a Landfill

Science.gov (United States)

Venner, Laura

2008-09-01

Engaging "K-to-Gray” audiences (children, families, and older adults) in astronomical activities is one of the main goals of the NJMC Center for Environmental and Scientific Education and the William D. McDowell Observatory located in Lyndhurst, NJ. Perched atop a closed and reclaimed municipal solid waste landfill, our new LEED - certified building (certification pending) and William D. McDowell observatory will assist in bringing the goals of IYA 2009 to the approximately 25,000 students and 15,000 adults that visit our site from the NY/NJ region each year. Diversifying our traditional environmental science offerings, we have incorporated astronomy into our repertoire with "The Sun Through Time” module, which includes storytelling, cultural astronomy, telescope anatomy, and other activities that are based on the electromagnetic spectrum and our current knowledge of the sun. These lessons have also been modified to bring astronomy to underserved communities, specifically those individuals that have dexterity or cognitive ability differences. The program is conducted in a classroom setting and is designed to meet New Jersey Core Curriculum Content Standards. With the installation of our new 20” telescope, students and amateur astronomers will be given the opportunity to perform rudimentary research. In addition, a program is in development that will allow individuals to measure local sky brightness and understand the effects of light pollution on astronomical viewing. Teaching astronomy in an urban setting presents many challenges. All individuals, regardless of ability level or location, should be given the opportunity to be exposed to the wonders of the universe and the MEC/CESE has been successful in providing those opportunities.

Teaching Astronomy in UK Schools

Science.gov (United States)

Roche, Paul; Roberts, Sarah; Newsam, Andy; Barclay, Charles

2012-01-01

This article attempts to summarise the good, bad and (occasionally) ugly aspects of teaching astronomy in UK schools. It covers the most common problems reported by teachers when asked about covering the astronomy/space topics in school. Particular focus is given to the GCSE Astronomy qualification offered by Edexcel (which is currently the…

Ground-based observations of exoplanet atmospheres

NARCIS (Netherlands)

Mooij, Ernst Johan Walter de

2011-01-01

This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

Wave impedance selection for passivity-based bilateral teleoperation

Science.gov (United States)

D'Amore, Nicholas John

When a task must be executed in a remote or dangerous environment, teleoperation systems may be employed to extend the influence of the human operator. In the case of manipulation tasks, haptic feedback of the forces experienced by the remote (slave) system is often highly useful in improving an operator's ability to perform effectively. In many of these cases (especially teleoperation over the internet and ground-to-space teleoperation), substantial communication latency exists in the control loop and has the strong tendency to cause instability of the system. The first viable solution to this problem in the literature was based on a scattering/wave transformation from transmission line theory. This wave transformation requires the designer to select a wave impedance parameter appropriate to the teleoperation system. It is widely recognized that a small value of wave impedance is well suited to free motion and a large value is preferable for contact tasks. Beyond this basic observation, however, very little guidance exists in the literature regarding the selection of an appropriate value. Moreover, prior research on impedance selection generally fails to account for the fact that in any realistic contact task there will simultaneously exist contact considerations (perpendicular to the surface of contact) and quasi-free-motion considerations (parallel to the surface of contact). The primary contribution of the present work is to introduce an approximate linearized optimum for the choice of wave impedance and to apply this quasi-optimal choice to the Cartesian reality of such a contact task, in which it cannot be expected that a given joint will be either perfectly normal to or perfectly parallel to the motion constraint. The proposed scheme selects a wave impedance matrix that is appropriate to the conditions encountered by the manipulator. This choice may be implemented as a static wave impedance value or as a time-varying choice updated according to the

TANGOO: A ground-based tilting-filter spectrometer for deriving the temperature in the mesopause region

Science.gov (United States)

Wildner, S.; Bittner, M.

2009-04-01

TANGOO (Tilting-filter spectrometer for Atmospheric Nocturnal Ground-based Oxygen & hydrOxyl emission measurements) is a passive, ground-based optical instrument for the purpose of a simultanously automatic long-term monitoring of OH(6-2) and O2 atm. Band (0-1) emissions (called "airglow"), yielding rotational temperatures in about 87 and 95 km, respectively. TANGOO, being a transportable and comparatively easy-to-use instrument, is the enhancement of the Argentine Airglow Spectrometer (Scheer, 1987) and shows significant improvements in the temporal resolution and throughput. It will be located on the German Enviromental Research Station "Schneefernerhaus", Zugspitze (47°,4 N, 11° E) and will start measurements in 2009. Objectives of TANGOO cover the analysis of dynamical processes such as gravity waves as well as the identification of climate signals. The observation method will be presented.

Astronomy all the time for everybody

Science.gov (United States)

Grigore, Valentin

2015-08-01

General contextCommunicating astronomy with the public must be done all year and with all community members using all the available methods to promote the all aspects of astronomy: education, science, research, new technologies, dark-sky protection, astrophotography, mythology, astropoetry, astro arts and music.An annual calendarTwo aspect must be taken in consideration when create a calendar of activity:- astronomical events (eclipses, meteor showers, comets, etc.)- international and local astronomical events: Global Astronomy Months, Astronomy Day, Globe at Night, ISAN, public activitiesCommunicating astronomy with the whole communityA description of the experience of the author organizing over 500 events in 30 years of activity including all the community members: general public, students, teachers, artists, authorities, people with disabilities, minor and adult prisoners, etc.An experience of seven years as TV producer of the astronomy TV show “Ùs and the Sky” is presented.Promotion of the activityThe relation with the mass-media is an important aspect communicating astronomy with the public.Mass-media between rating and correct information of the public.The role of the cooperation with the community in astronomy projectsA successful model: EURONEAR project

Colloquium: Multimessenger astronomy with gravitational waves and high-energy neutrinos

NARCIS (Netherlands)

Ando, S.; Baret, B.; Bartos, I.; Bouhou, B.; Chassande-Mottin, E.; Corsi, A.; Di Palma, I.; Dietz, A.; Donzaud, C.; Eichler, D.; Finley, C.; Guetta, D.; Halzen, F.; Jones, G.; Kandhasamy, S.; Kotake, K.; Kouchner, A.; Mandic, V.; Márka, S.; Márka, Z.; Moscoso, L.; Papa, M.A.; Piran, T.; Pradier, T.; Romero, G.E.; Sutton, P.; Thrane, E.; van Elewyck, V.; Waxman, E.

2013-01-01

Many of the astrophysical sources and violent phenomena observed in our Universe are potential emitters of gravitational waves and high-energy cosmic radiation, including photons, hadrons, and presumably also neutrinos. Both gravitational waves (GW) and high-energy neutrinos (HEN) are cosmic

Armenian Archaeoastronomy and Astronomy in Culture

Science.gov (United States)

Mickaelian, Areg M.; Farmanyan, Sona V.

2016-12-01

A review is given on archaeoastronomy in Armenia and astronomical knowledge reflected in the Armenian culture. Astronomy in Armenia was popular since ancient times and Armenia is rich in its astronomical heritage, such as the names of the constellations, ancient observatories, Armenian rock art (numerous petroglyphs of astronomical content), ancient and medieval Armenian calendars, astronomical terms and names used in Armenian language since II-I millennia B.C., records of astronomical events by ancient Armenians (e.g. Halley's comet in 87 B.C., supernovae explosion in 1054), the astronomical heritage of the Armenian medieval great thinker Anania Shirakatsi's (612-685), medieval sky maps and astronomical devices by Ghukas (Luca) Vanandetsi (XVII-XVIII centuries) and Mkhitar Sebastatsi (1676-1749), etc. For systemization and further regular studies, we have created a webpage devoted to Armenian archaeoastronomical matters at Armenian Astronomical Society (ArAS) website. Issues on astronomy in culture include astronomy in ancient Armenian cultures, ethnoastronomy, astronomy in Armenian religion and mythology, astronomy and astrology, astronomy in folklore and poetry, astronomy in arts, astrolinguistics and astroheraldry. A similar webpage for Astronomy in Armenian Culture is being created at ArAS website and a permanent section "Archaeoastronomy and Astronomy in Culture" has been created in ArAS Electronic Newsletter. Several meetings on this topic have been organized in Armenia during 2007-2014, including the archaeoastronomical meetings in 2012 and 2014, and a number of books have been published. Several institutions are related to these studies coordinated by Byurakan Astrophysical Observatory (BAO) and researchers from the fields of astronomy, history, archaeology, literature, linguistics, etc. are involved.

Forward modeling of seepage of reservoir dam based on ground penetrating radar

Directory of Open Access Journals (Sweden)

Xueli WU

2017-08-01

Full Text Available The risk of the reservoir dam seepage will bring the waste of water resources and the loss of life and property. The ground penetrating radar (GPR is designed as a daily inspection system of dams to improve the existing technology which can't determine the actual situation of the dam seepage tunnel coordinates. The finite difference time domain (FDTD is used to solve the Yee's grids discreatization in two-dimensional space, and its electromagnetic distribution equation is obtained as well. Based on the actual structure of reservoir dam foundation, the ideal model of air layer, concrete layer, clay layer and two water seepage holes is described in detail, and the concrete layer interference model with limestone interference point is established. The system architecture is implemented by using MATLAB, and the forward modeling is performed. The results indicate that ground penetrating radar can be used for deep target detection. Through comparing the detection spectrum of three kinds of frequency electromagnetic wave by changing the center frequency of the GPR electromagnetic wave of 50 MHz, 100 MHz and 200 MHz, it is concluded that the scanning result is more accurate at 100 MHz. At the same time, the simulation results of the interference model show that this method can be used for the detection of complex terrain.

Remote sensing the plasmasphere, plasmapause, plumes and other features using ground-based magnetometers

Directory of Open Access Journals (Sweden)

Menk Frederick

2014-01-01

Full Text Available The plasmapause is a highly dynamic boundary between different magnetospheric particle populations and convection regimes. Some of the most important space weather processes involve wave-particle interactions in this region, but wave properties may also be used to remote sense the plasmasphere and plasmapause, contributing to plasmasphere models. This paper discusses the use of existing ground magnetometer arrays for such remote sensing. Using case studies we illustrate measurement of plasmapause location, shape and movement during storms; refilling of flux tubes within and outside the plasmasphere; storm-time increase in heavy ion concentration near the plasmapause; and detection and mapping of density irregularities near the plasmapause, including drainage plumes, biteouts and bulges. We also use a 2D MHD model of wave propagation through the magnetosphere, incorporating a realistic ionosphere boundary and Alfvén speed profile, to simulate ground array observations of power and cross-phase spectra, hence confirming the signatures of plumes and other density structures.

GRACILE: a comprehensive climatology of atmospheric gravity wave parameters based on satellite limb soundings

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M. Ern

2018-04-01

Full Text Available Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processes involve even smaller scales. Therefore, general circulation models (GCMs and chemistry climate models (CCMs usually parametrize the effect of gravity waves on the global circulation. These parametrizations are very simplified. For this reason, comparisons with global observations of gravity waves are needed for an improvement of parametrizations and an alleviation of model biases. We present a gravity wave climatology based on atmospheric infrared limb emissions observed by satellite (GRACILE. GRACILE is a global data set of gravity wave distributions observed in the stratosphere and the mesosphere by the infrared limb sounding satellite instruments High Resolution Dynamics Limb Sounder (HIRDLS and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER. Typical distributions (zonal averages and global maps of gravity wave vertical wavelengths and along-track horizontal wavenumbers are provided, as well as gravity wave temperature variances, potential energies and absolute momentum fluxes. This global data set captures the typical seasonal variations of these parameters, as well as their spatial variations. The GRACILE data set is suitable for scientific studies, and it can serve for comparison with other instruments (ground-based, airborne, or other satellite instruments and for comparison with gravity wave distributions, both resolved and parametrized, in GCMs and CCMs. The GRACILE data set is available as supplementary data at https://doi.org/10.1594/PANGAEA.879658.

Astronomy, Indigenous Knowledge and Interpretation: Advancing studies of Cultural Astronomy in South Africa

OpenAIRE

Holbrook, Jarita

2016-01-01

The International Society for Archaeoastronomy and Astronomy in Culture (ISAAC) Oxford X conference came to Africa for the first time in 2014. Oxford X exposed South African students and researchers to cultural astronomy data collection and analysis methods, as well as to potential mentors to further the goal of advancing the field. Cultural Astronomy studies in South Africa, however, remain in a nascent stage, which in some ways can be said for the entire field, but especially when it comes ...

Topological Invariants and Ground-State Wave functions of Topological Insulators on a Torus

Directory of Open Access Journals (Sweden)

Zhong Wang

2014-01-01

Full Text Available We define topological invariants in terms of the ground-state wave functions on a torus. This approach leads to precisely defined formulas for the Hall conductance in four dimensions and the topological magnetoelectric θ term in three dimensions, and their generalizations in higher dimensions. They are valid in the presence of arbitrary many-body interactions and disorder. These topological invariants systematically generalize the two-dimensional Niu-Thouless-Wu formula and will be useful in numerical calculations of disordered topological insulators and strongly correlated topological insulators, especially fractional topological insulators.

Fundamental astronomy

CERN Document Server

Kröger, Pekka; Oja, Heikki; Poutanen, Markku; Donner, Karl

2017-01-01

Now in its sixth edition this successful undergraduate textbook gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The chapters on galactic and extragalactic astronomy as well as cosmology were extensively modernized in the previous edition. In this new edition they have been further revised to include more recent results. The long chapter on the solar system has been split into two parts: the first one deals with the general properties, and the other one describes individual objects. A new chapter on exoplanets has been added to the end of the book next to the chapter on astrobiology. In response to the fact that astronomy has evolved enormously over the last few years, only a few chapters of this book have been left unmodified. Long considered a standard text for physical science maj...

Skynet Junior Scholars: Bringing Astronomy to Deaf and Hard of Hearing Youth

Science.gov (United States)

Meredith, Kate; Williamson, Kathryn; Gartner, Constance; Hoette, Vivian L.; Heatherly, Sue Ann

2016-01-01

Skynet Junior Scholars (SJS), funded by the National Science Foundation, aims to engage middle school youth from diverse audiences in investigating the universe with research quality robotic telescopes. SJS project development goals include: 1) Online access to optical and radio telescopes, data analysis tools, and professional astronomers, 2) An age-appropriate web-based interface for controlling remote telescopes, 3) Inquiry-based standards-aligned instructional modules. From an accessibility perspective, the goal of the Skynet Junior Scholars project is to facilitate independent access to the project by all youth including those with blindness or low vision and those who are Deaf or Hard of Hearing.Deaf and Hard of Hearing (DHH) students have long been an underserved population within STEM fields, including astronomy. Two main barriers include: (1) insufficient corpus of American Sign Language (ASL) for astronomy terminology, and (2) DHH education professionals who lack astronomy background. A suite of vocabulary, accessible hands-on activities, and interaction with trained professionals, are critical for enhancing the background experiences of DHH youth, as they may come to an astronomy lesson lacking the basic "incidental learning" that is often taken for granted with hearing peers (for example, from astronomy in the media).A collaboration between the Skynet Junior Scholars (SJS) project and the Wisconsin School for the Deaf is bringing astronomy to the DHH community in an accessible way for the first time. We follow a group of seven DHH youth over one semester as they interact with the SJS tools and curriculum to understand how they assimilate astronomy experiences and benefit from access to telescopes both directly (on school campus and at Yerkes Observatory) and through Skynet's robotic telescope network (optical and radio telescopes, inquiry-based modules, data analysis tools, and professional astronomers). We report on our first findings of resources and

Survey of Object-Based Data Reduction Techniques in Observational Astronomy

Directory of Open Access Journals (Sweden)

Łukasik Szymon

2016-01-01

Full Text Available Dealing with astronomical observations represents one of the most challenging areas of big data analytics. Besides huge variety of data types, dynamics related to continuous data flow from multiple sources, handling enormous volumes of data is essential. This paper provides an overview of methods aimed at reducing both the number of features/attributes as well as data instances. It concentrates on data mining approaches not related to instruments and observation tools instead working on processed object-based data. The main goal of this article is to describe existing datasets on which algorithms are frequently tested, to characterize and classify available data reduction algorithms and identify promising solutions capable of addressing present and future challenges in astronomy.

A Partnership in Observational and Computational Astronomy (POCA)

Science.gov (United States)

Walter, Donald K.; Brittain, S. D.; Cash, J. L.; Hartmann, D. H.; Howell, S. B.; King, J. R.; Leising, M. D.; Mayo, E. A.; Mighell, K. J.; Smith, D. M., Jr.

2009-01-01

A partnership has been established between South Carolina State University (SCSU, a Historically Black College/University), the National Optical Astronomy Observatory (NOAO) and Clemson University (CU) under an award from NSF's "Partnerships in Astronomy and Astrophysics Research and Education (PAARE)" program. The mission of POCA is to develop an effective, long-term partnership that combines the strengths of the three institutions to increase the scientific and educational output of all the partners with special emphasis on enhancing diversity in the field of astronomy. Components of the program include enhancing faculty and student research in astronomy at SCSU, recruiting and retaining underrepresented minority students into the field, outreach through planetarium programs and museum exhibits and developing web based resources in astronomy education. Activities in the first year of the program are discussed. We have begun developing and testing several new astronomy laboratory exercises. Our first summer internship program has concluded successfully. With PAARE scholarship money, we are now supporting four physics majors at SCSU who have chosen the astronomy option (concentration) for their degree. SCSU undergraduates have acquired observing experience on the KPNO Mayall 4-meter telescope under the guidance of faculty and graduate students from CU. NOAO astronomers have collaborated with SCSU faculty to begin a research program that studies RV Tauri stars. Funds from PAARE are supporting follow-up research to a just-completed doctoral dissertation by E. A. Mayo described elsewhere in these proceedings. Future plans for graduate fellowships and related activities are discussed in addition to summer internships for POCA undergraduates at CU and NOAO. Support for this work was provided by the NSF PAARE program to South Carolina State University under award AST-0750814.

Bad Astronomy Goes Hollywood

Science.gov (United States)

Plait, P.

2003-05-01

It can be argued that astronomy is the oldest of all the sciences, so you'd think that after all this time people would have a pretty good understanding of it. In reality, however, misconceptions about astronomy abound, and even basic concepts are misunderstood. There are many sources of these cosmic misconceptions, including incorrect textbooks, parents and/or teachers who don't understand astronomy and therefore spread misinformation, urban legends, and so on. Perhaps the most pervasive source of bad astronomy is Hollywood. Science fiction movies are enormously popular, but are commonly written and directed by people who don't have even a passing familiarity with astronomy. The smash hit "Armageddon" (the number one box office movie of 1998), for example, used vast quantities of incorrect astronomy in the plot. It reinforced such popular misconceptions as huge asteroids impacting the Earth with little warning, small meteorites being hot when they impact, air existing in space, and that a simple bomb can blow up an asteroid the size of a small moon (even when the bomb is buried only 800 feet deep!). However, movie scenes can be used as a hook that engages the student, helping them learn and remember the correct science. In this talk, I will light-heartedly discuss specific examples of common misinformation, using movie clips, diagrams, and a splash of common sense to show just where Hollywood gets it wrong, and what you can do to help students and the public get it right.

Traveling-Wave Tube Amplifier Second Harmonic as Millimeter-Wave Beacon Source for Atmospheric Propagation Studies

Science.gov (United States)

Simons, Rainee N.; Wintucky, Edwin G.

2014-01-01

This paper presents the design and test results of a CW millimeter-wave satellite beacon source, based on the second harmonic from a traveling-wave tube amplifier and utilizes a novel waveguide multimode directional coupler. A potential application of the beacon source is for investigating the atmospheric effects on Q-band (37-42 GHz) and V/W-band (71- 76 GHz) satellite-to-ground signals.

The Relationship between Preservice Science Teachers' Attitude toward Astronomy and Their Understanding of Basic Astronomy Concepts

Science.gov (United States)

Bektasli, Behzat

2016-01-01

Turkish preservice science teachers have been taking a two-credit astronomy class during the last semester of their undergraduate program since 2010. The current study aims to investigate the relationship between preservice science teachers' astronomy misconceptions and their attitudes toward astronomy. Preservice science teachers were given an…

The effect of regional variation of seismic wave attenuation on the strong ground motion from earthquakes

Energy Technology Data Exchange (ETDEWEB)

Chung, D H; Bernreuter, D L

1981-10-01

Attenuation is caused by geometric spreading and absorption. Geometric spreading is almost independent of crustal geology and physiographic region, but absorption depends strongly on crustal geology and the state of the earth's upper mantle. Except for very high frequency waves, absorption does not affect ground motion at distances less than about 25 to 50 km. Thus, in the near-field zone, the attenuation in the eastern United States is similar to that in the western United States. Beyond the near field, differences in ground motion can best be accounted for by differences in attenuation caused by differences in absorption. The stress drop of eastern earthquakes may be higher than for western earthquakes of the same seismic moment, which would affect the high-frequency spectral content. But we believe this factor is of much less significance than differences in absorption in explaining the differences in ground motion between the East and the West. The characteristics of strong ground motion in the conterminous United States are discussed in light of these considerations, and estimates are made of the epicentral ground motions in the central and eastern United States. (author)

From Conceptual Frameworks to Mental Models for Astronomy: Students' Perceptions

Science.gov (United States)

Pundak, David; Liberman, Ido; Shacham, Miri

2017-01-01

Considerable debate exists among discipline-based astronomy education researchers about how students change their perceptions in science and astronomy. The study questioned the development of astronomical models among students in institutions of higher education by examining how college students change their initial conceptual frameworks and…

White supremacism and Islamic astronomy in history of astronomy texts from the eighteenth century to the present day

Science.gov (United States)

Lockard, Joe

2018-04-01

This paper reviews manifestations of racism in European and American histories of Arab and Persian astronomy from the eighteenth century to the present day. Its first section discusses representation of Islamic astronomy from Adam Smith to late Victorian writers, particularly tracing ideas of Arab unoriginality and scientific incapacity. The second section first relates the appearance of scientific racism in the early twentieth-century historiography of astronomy, then how the rise of scientifically and linguistically competent scholarship in the latter twentieth century provided much-improved information on Islamic achievements in astronomy. The paper’s conclusion underlines the importance of avoiding ethnic supremacism and integrating research on Islamic astronomy into teaching and publishing on the history of astronomy.

Preservice elementary teachers learning of astronomy

Science.gov (United States)

Fidler, Chuck Gary

The dissertation presents a new approach for the study of preservice elementary teacher astronomy education. The approach suggests that learning astronomical concepts are facilitated by greater sophistication in scale perception and spatial-aptitude. This dissertation is underscored by the national call for elementary science education reform efforts and suggests certain strategies shown more effective for the development of accurate astronomical comprehension. The present research study describes how preservice elementary teachers conceptualize and communicate ideas about Space. Instead of assuming a universal mental conception of cosmic orientations and relationships, the dissertation claims that the perception of Space related dimensions vary among preservice elementary teachers. Furthermore, the dissertation suggests individual perceptions of the scale sizes and orientations of celestial systems have direct influences on mental models used to organize and communicate astronomical information. The development of inaccurate mental models of the scaled dimensions of Space may perpetuate the teacher-student cycle of misconception and naive-theory generation among children in elementary education settings. The ability to conceptualize the vast cosmos is facilitated by the minds ability to think about vast scales and orientations of celestial objects. The Earth-based perspective of astronomy education compels the learner to think about astronomical principles within imaginary frames of reference and across unfamiliar scaled dimensions. Therefore, mental astronomical model building is underscored by the perception of scale and cosmic spatiality. This study suggests these cognitive skill sets are interconnected and facilitate the learning of accurate astronomy principles; as well as play an important role when designing an astronomy education program for preservice elementary teachers. This research study is comprised of three separate standalone articles designed and

Astronomy essentials

CERN Document Server

Brass, Charles O

2012-01-01

REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Astronomy includes the historical perspective of astronomy, sky basics and the celestial coordinate systems, a model and the origin of the solar system, the sun, the planets, Kepler'

Millimeter-wave antennas configurations and applications

CERN Document Server

du Preez, Jaco

2016-01-01

This book comprehensively reviews the state of the art in millimeter-wave antennas, traces important recent developments and provides information on a wide range of antenna configurations and applications. While fundamental theoretical aspects are discussed whenever necessary, the book primarily focuses on design principles and concepts, manufacture, measurement techniques, and practical results. Each of the various antenna types scalable to millimeter-wave dimensions is considered individually, with coverage of leaky-wave and surface-wave antennas, printed antennas, integrated antennas, and reflector and lens systems. The final two chapters address the subject from a systems perspective, providing an overview of supporting circuitry and examining in detail diverse millimeter-wave applications, including high-speed wireless communications, radio astronomy, and radar. The vast amount of information now available on millimeter-wave systems can be daunting for researchers and designers entering the field. This b...

Sounding rocket/ground-based observation campaign to study Medium-Scale Traveling Ionospheric Disturbances (MSTID)

Science.gov (United States)

Yamamoto, M.; Yokoyama, T.; Saito, A.; Otsuka, Y.; Yamamoto, M.; Abe, T.; Watanabe, S.; Ishisaka, K.; Saito, S.; Larsen, M.; Pfaff, R. F.; Bernhardt, P. A.

2012-12-01

An observation campaign is under preparation. It is to launch sounding rockets S-520-27 and S-310-42 from Uchinoura Space Center of JAXA while ground-based instruments measure waves in the ionosphere. It is scheduled in July/August 2013. The main purpose of the experiment is to reveal generation mechanism of Medium-Scale Traveling Ionospheric Disturbance (MSTID). The MSTID is the ionospheric wave with 1-2 hour periodicity, 100-200 km horizontal wavelength, and southwestward propagation. It is enhanced in the summer nighttime of the mid-latitude ionosphere. The MSTID is not only a simple atmospheric-wave modulation of the ionosphere, but shows similarity to characteristics of the Perkins instability. A problem is that growth rate of the Perkins instability is too small to explain the phenomena. We now hypothesize a generation mechanism that electromagnetic coupling of the F- and E-regions help rapid growth of the MSTID especially at its initial stage. In the observation campaign, we will use the sounding rocket S-520-27 for in-situ measurement of ionospheric parameters, i.e., electron density and electric fields. Wind velocity measurements in both F- and E-regions are very important as well. For the F-region winds, we will conduct Lithium-release experiment under the full-moon condition. This is a big technical challenge. Another rocket S-310-42 will be used for the E-region wind measurement with the TMA release. On the ground, we will use GEONET (Japanese vast GPS receiver network) to monitor horizontal distribution of GPS-TEC on the realtime bases. In the presentation we will show MSTID characteristics and the proposed generation mechanism, and discuss plan and current status of the project.

Learning Application of Astronomy Based Augmented Reality using Android Platform

Science.gov (United States)

Maleke, B.; Paseru, D.; Padang, R.

2018-02-01

Astronomy is a branch of science involving observations of celestial bodies such as stars, planets, nebular comets, star clusters, and galaxies as well as natural phenomena occurring outside the Earth’s atmosphere. The way of learning of Astronomy is quite varied, such as by using a book or observe directly with a telescope. But both ways of learning have shortcomings, for example learning through books is only presented in the form of interesting 2D drawings. While learning with a telescope requires a fairly expensive cost to buy the equipment. This study will present a more interesting way of learning from the previous one, namely through Augmented Reality (AR) application using Android platform. Augmented Reality is a combination of virtual world (virtual) and real world (real) made by computer. Virtual objects can be text, animation, 3D models or videos that are combined with the actual environment so that the user feels the virtual object is in his environment. With the use of the Android platform, this application makes the learning method more interesting because it can be used on various Android smartphones so that learning can be done anytime and anywhere. The methodology used in making applications is Multimedia Lifecycle, along with C # language for AR programming and flowchart as a modelling tool. The results of research on some users stated that this application can run well and can be used as an alternative way of learning Astronomy with more interesting.

Online Scholarly Conversations in General Education Astronomy Courses

Science.gov (United States)

Cai, Qijie; Wong, Ka-Wah

2018-01-01

In general education astronomy courses, many students are struggling with understanding the foundational concepts and theories in astronomy. One of the possible reasons is that, due the large class size, many of the courses are taught using a lecture mode, where human interactions and active learning are limited (Freeman et al., 2014). To address this challenge, we have applied the knowledge building framework (Scardamalia & Bereiter, 2006) to design an online collaborative learning component, called Scholarly Conversations, to be integrated into a general education astronomy course at a public, comprehensive university.During Scholarly Conversations, students are treated as scholars to advance knowledge frontiers (Scardamalia & Bereiter, 2006). The whole process involves the creation of new ideas and requires discourse and collective work for the advancement and creation of artifacts, such as theories and models (van Aalst, 2009). Based on the knowledge building principles (Scardamalia, 2002; Zhang, Scardamalia, Reeve, & Messina, 2009), several features have been built into Scholarly Conversations so that students are guided to deepen understanding of the astronomy concepts through three phases: knowledge sharing, knowledge construction and knowledge building, and reflections on learning growth (van Aalst, 2009; Cai, 2017). The online Scholarly Conversation is an extension of the lecture component of the general education astronomy course. It promotes student interactions and collaborative learning, and provides scaffolds for students to construct meanings of the essential concepts in astronomy through social learning and online technology. In this presentation, we will explain the specific design principles of the online Scholarly Conversation, and share the artifacts created to facilitate the online conversations in an general education astronomy course.Note: This project has been supported by the College of Education Research Grant Program at Minnesota State

The Correlation between Pre-Service Science Teachers' Astronomy Achievement, Attitudes towards Astronomy and Spatial Thinking Skills

Science.gov (United States)

Türk, Cumhur

2016-01-01

The purpose of this study was to examine the changes in pre-service Science teachers' astronomy achievement, attitudes towards astronomy and skills for spatial thinking in terms of their years of study. Another purpose of the study was to find out whether there was correlation between pre-service teachers' astronomy achievement, attitudes towards…

Astronomy Education Programs at the Smithsonian National Air and Space Museum

Science.gov (United States)

Nagy, Katie; de Messieres, G.; Edson, S.

2014-01-01

Astronomy educators present the range of astronomy education programming available at the National Air and Space Museum, including the following. In the Phoebe Waterman Haas Public Observatory, visitors use telescopes and other scientific equipment to observe and discuss the Sun, Venus, and other celestial sights in an unstructured, inquiry-based environment. At Discovery Stations throughout the Museum, staff and volunteers engage visitors in hands-on exploration of a wide range of artifacts and teaching materials. Astronomy-related Discovery Stations include Cosmic Survey, an exploration of gravitational lensing using a rubber sheet, spectroscopy using discharge tubes, and several others. Astronomy lectures in the planetarium or IMAX theater, featuring researchers as the speakers, include a full evening of activities: a custom pre-lecture Discovery Station, a handout to help visitors explore the topic in more depth, and evening stargazing at the Public Observatory. Astronomy educators present planetarium shows, including star tours and explorations of recent science news. During Astronomy Chat, an astronomy researcher engages visitors in an informal conversation about science. The goal is to make the public feel welcome in the environment of professional research and to give busy scientists a convenient outreach opportunity. Astronomy educators also recruit, train, and coordinate a corps of volunteers who contribute their efforts to the programming above. The volunteer program has grown significantly since the Public Observatory was built in 2009.

Matching Matched Filtering with Deep Networks for Gravitational-Wave Astronomy

Science.gov (United States)

Gabbard, Hunter; Williams, Michael; Hayes, Fergus; Messenger, Chris

2018-04-01

We report on the construction of a deep convolutional neural network that can reproduce the sensitivity of a matched-filtering search for binary black hole gravitational-wave signals. The standard method for the detection of well-modeled transient gravitational-wave signals is matched filtering. We use only whitened time series of measured gravitational-wave strain as an input, and we train and test on simulated binary black hole signals in synthetic Gaussian noise representative of Advanced LIGO sensitivity. We show that our network can classify signal from noise with a performance that emulates that of match filtering applied to the same data sets when considering the sensitivity defined by receiver-operator characteristics.

Matching Matched Filtering with Deep Networks for Gravitational-Wave Astronomy.

Science.gov (United States)

Gabbard, Hunter; Williams, Michael; Hayes, Fergus; Messenger, Chris

2018-04-06

We report on the construction of a deep convolutional neural network that can reproduce the sensitivity of a matched-filtering search for binary black hole gravitational-wave signals. The standard method for the detection of well-modeled transient gravitational-wave signals is matched filtering. We use only whitened time series of measured gravitational-wave strain as an input, and we train and test on simulated binary black hole signals in synthetic Gaussian noise representative of Advanced LIGO sensitivity. We show that our network can classify signal from noise with a performance that emulates that of match filtering applied to the same data sets when considering the sensitivity defined by receiver-operator characteristics.

An Analysis of Conjugate Ground-based and Space-based Measurements of Energetic Electrons during Substorms

Science.gov (United States)

Sivadas, N.; Semeter, J. L.

2015-12-01

Substorms within the Earth's magnetosphere release energy in the form of energetic charged particles and several kinds of waves within the plasma. Depending on their strength, satellite-based navigation and communication systems are adversely affected by the energetic charged particles. Like many other natural phenomena, substorms can have a severe economic impact on a technology-driven society such as ours. Though energization of charged particles is known to occur in the magnetosphere during substorms, the source of this population and its relation to traditional acceleration region dynamics, are not completely understood. Combining measurements of energetic charged particles within the plasmasheet and that of charged particles precipitated in to the ionosphere will provide a better understanding of the role of processes that accelerate these charged particles. In the current work, we present energetic electron flux measured indirectly using data from ground-based Incoherent Scatter Radar and that measured directly at the plasmasheet by the THEMIS spacecraft. Instances of low-altitude-precipitation observed from ground suggest electrons of energy greater than 300 keV, possibly arising from particle injection events during substorms at the magnetically conjugate locations in the plasmasheet. The differences and similarities in the measurements at the plasmasheet and the ionosphere indicate the role different processes play in influencing the journey of these energetic particles form the magnetosphere to the ionosphere. Our observations suggest that there is a lot more to be understood of the link between magnetotail dynamics and energetic electron precipitation during substorms. Understanding this may open up novel and potentially invaluable ways of diagnosing the magnetosphere from the ground.

Astronomy in Australia

Science.gov (United States)

Watson, F.; Couch, W.

2017-12-01

Australians have watched the sky for tens of thousands of years. The nineteenth century saw the foundation of government observatories in capital cities such as Sydney and Melbourne. While early twentieth-century astronomy focused largely on solar physics, the advent of radio astronomy at the end of the Second World War enabled Australia to take a leading role in the new science, with particular emphasis on low-frequency studies. Today, the radio quietness of its outback interior provides an excellent location for the Australian core of the Square Kilometre Array. Australian optical astronomy has flourished since the 1960s, with the 3.9-metre Anglo-Australian Telescope becoming the principal national facility in 1974. Access to ESO’s facilities at the La Silla Paranal Observatory is warmly welcomed by all Australian astronomers.

GRACILE: a comprehensive climatology of atmospheric gravity wave parameters based on satellite limb soundings

Science.gov (United States)

Ern, Manfred; Trinh, Quang Thai; Preusse, Peter; Gille, John C.; Mlynczak, Martin G.; Russell, James M., III; Riese, Martin

2018-04-01

Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processes involve even smaller scales. Therefore, general circulation models (GCMs) and chemistry climate models (CCMs) usually parametrize the effect of gravity waves on the global circulation. These parametrizations are very simplified. For this reason, comparisons with global observations of gravity waves are needed for an improvement of parametrizations and an alleviation of model biases. We present a gravity wave climatology based on atmospheric infrared limb emissions observed by satellite (GRACILE). GRACILE is a global data set of gravity wave distributions observed in the stratosphere and the mesosphere by the infrared limb sounding satellite instruments High Resolution Dynamics Limb Sounder (HIRDLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). Typical distributions (zonal averages and global maps) of gravity wave vertical wavelengths and along-track horizontal wavenumbers are provided, as well as gravity wave temperature variances, potential energies and absolute momentum fluxes. This global data set captures the typical seasonal variations of these parameters, as well as their spatial variations. The GRACILE data set is suitable for scientific studies, and it can serve for comparison with other instruments (ground-based, airborne, or other satellite instruments) and for comparison with gravity wave distributions, both resolved and parametrized, in GCMs and CCMs. The GRACILE data set is available as supplementary data at https://doi.org/10.1594/PANGAEA.879658" target="_blank">https://doi.org/10.1594/PANGAEA.879658.

Spin-wave logic devices based on isotropic forward volume magnetostatic waves

International Nuclear Information System (INIS)

Klingler, S.; Pirro, P.; Brächer, T.; Leven, B.; Hillebrands, B.; Chumak, A. V.

2015-01-01

We propose the utilization of isotropic forward volume magnetostatic spin waves in modern wave-based logic devices and suggest a concrete design for a spin-wave majority gate operating with these waves. We demonstrate by numerical simulations that the proposed out-of-plane magnetized majority gate overcomes the limitations of anisotropic in-plane magnetized majority gates due to the high spin-wave transmission through the gate, which enables a reduced energy consumption of these devices. Moreover, the functionality of the out-of-plane majority gate is increased due to the lack of parasitic generation of short-wavelength exchange spin waves

Spin-wave logic devices based on isotropic forward volume magnetostatic waves

Energy Technology Data Exchange (ETDEWEB)

Klingler, S., E-mail: stefan.klingler@wmi.badw-muenchen.de; Pirro, P.; Brächer, T.; Leven, B.; Hillebrands, B.; Chumak, A. V. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany)

2015-05-25

We propose the utilization of isotropic forward volume magnetostatic spin waves in modern wave-based logic devices and suggest a concrete design for a spin-wave majority gate operating with these waves. We demonstrate by numerical simulations that the proposed out-of-plane magnetized majority gate overcomes the limitations of anisotropic in-plane magnetized majority gates due to the high spin-wave transmission through the gate, which enables a reduced energy consumption of these devices. Moreover, the functionality of the out-of-plane majority gate is increased due to the lack of parasitic generation of short-wavelength exchange spin waves.

Transient Analysis of Dispersive Power-Ground Plate Pairs With Arbitrarily Shaped Antipads by the DGTD Method With Wave Port Excitation

KAUST Repository

Li, Ping; Jiang, Li Jun; Bagci, Hakan

2016-01-01

A discontinuous Galerkin time-domain (DGTD) method analyzing signal/power integrity on multilayered power-ground parallel plate pairs is proposed. The excitation is realized by introducing wave ports on the antipads where electric/magnetic current

Astronomy adventures and vacations how to get the most out of astronomy in your leisure time

CERN Document Server

Treadwell, Timothy

2017-01-01

This astronomy travel guide examines the many wonderful opportunities for experiencing the observing hobby. Amateur astronomy is often consigned to observing from home or from a local park, yet it can be much more. Tim Treadwell explores all the possibilities of astronomical and space-related activities that are available on day trips and longer vacations. These activities range from observatory visits and other simple ways to build an astronomy event into a holiday, to full blown specialized astronomy travel. Many trips give the opportunity to visit some of the world’s famous attractions. On most vacations it can be a matter of just taking a day (or night) out of your schedule to fit in an astronomy event, but larger, dedicated pilgrimages are also possible. How to make the most of astronomy potential on a holiday, whether observing on the beach in Hawaii with the Telescope Guy or visiting Star City in Russia, is covered in detail. Go to a star party, explore the national parks or see the northern lights! ...

Ocean waves monitor system by inland microseisms

Science.gov (United States)

Lin, L. C.; Bouchette, F.; Chang, E. T. Y.

2016-12-01

Microseisms are continuous ground oscillations which have been wildly introduced for decades. It is well known that the microseismicity in the frequency band from 0.05 to about 1 Hz partly results from ocean waves, which has been first explained by Longuet-Higgins [1950]. The generation mechanism for such a microseismicity is based on nonlinear wave-wave interactions which drive pressure pulses within the seafloor. The resulting ground pressure fluctuations yield ground oscillations at a double frequency (DF) with respect to that of current ocean waves. In order to understand the characteristics of DF microseisms associated with different wave sources, we aim to analyze and interpret the spectra of DF microseisms by using the simple spectrum method [Rabinovich, 1997] at various inland seismometer along the Taiwan coast. This is the first monitoring system of ocean waves observed by inland seismometers in Taiwan. The method is applied to identify wave sources by estimating the spectral ratios of wave induced microseisms associated with local winds and typhoons to background spectra. Microseism amplitudes above 0.2 Hz show a good correlation with wind-driven waves near the coast. Comparison of microseism band between 0.1 and 0.2 Hz with buoys in the deep sea shows a strong correlation of seismic amplitude with storm generated waves, implying that such energy portion originates in remote regions. Results indicate that microseisms observed at inland sites can be a potential tool for the tracking of typhoon displacements and the monitoring of extreme ocean waves in real time. Real- time Microseism-Ocean Waves Monitoring Website (http://mwave.droppages.com/) Reference Rabinovich, A. B. (1997) "Spectral analysis of tsunami waves: Separation of source and topography effects," J. Geophys. Res., Vol. 102, p. 12,663-12,676. Longuet-Higgins, M.S. (1950) "A theory of origin of microseisms," Philos. Trans. R. Soc., A. 243, pp. 1-35.

Ground-based solar radio observations of the August 1972 events

International Nuclear Information System (INIS)

Bhonsle, R.V.; Degaonkar, S.S.; Alurkar, S.K.

1976-01-01

Ground-based observations of the variable solar radio emission ranging from few millimetres to decametres have been used here as a diagnostic tool to gain coherent phenomenological understanding of the great 2, 4 and 7 August, 1972 solar events in terms of dominant physical processes like generation and propagation of shock waves in the solar atmosphere, particle acceleration and trapping. Four major flares are selected for detailed analysis on the basis of their ability to produce energetic protons, shock waves, polar cap absorptions (PCA) and sudden commencement (SC) geomagnetic storms. A comparative study of their radio characteristics is made. Evidence is seen for the pulsations during microwave bursts by the mechanism similar to that proposed by McLean et al. (1971), to explain the pulsations in the metre wavelength continuum radiation. It is suggested that the multiple peaks observed in some microwave bursts may be attributable to individual flares occurring sequentially due to a single initiating flare. Attempts have been made to establish identification of Type II bursts with the interplanetary shock waves and SC geomagnetic storms. Furthermore, it is suggested that it is the mass behind the shock front which is the deciding factor for the detection of shock waves in the interplantary space. It appears that more work is necessary in order to identify which of the three moving Type IV bursts (Wild and Smerd, 1972), namely, advancing shock front, expanding magnetic arch and ejected plasma blob serves as the piston-driver behind the interplanetary shocks. The existing criteria for proton flare prediction have been summarized and two new criteria have been proposed. (Auth.)

Testing strong gravity with gravitational waves and Love numbers

International Nuclear Information System (INIS)

Franzin, E; Cardoso, V; Raposo, G; Pani, P

2017-01-01

The LIGO observation of GW150914 has inaugurated the gravitational-wave astronomy era and the possibility of testing gravity in extreme regimes. While distorted black holes are the most convincing sources of gravitational waves, similar signals might be produced also by other compact objects. In particular, we discuss what the gravitational-wave ringdown could tell us about the nature of the emitting object, and how measurements of the tidal Love numbers could help us in understanding the internal structure of compact dark objects. (paper)

Using periodicity to mitigate ground vibration

DEFF Research Database (Denmark)

Andersen, Lars Vabbersgaard

2015-01-01

Introduction of trenches, barriers and wave impeding blocks on the transmission path between a source and receiver can be used for mitigation of ground vibration. However, to be effective a barrier must have a depth of about one wavelength of the waves to be mitigated. Hence, while great reductions......: A soil with periodic stiffening (ground improvement) and a ground with periodic changes in the surface elevation obtained by artificial landscaping. By means of a two-dimensional finite-element model, the stiffness and mass matrices are determined for a single cell of the ground with horizonal...

The two-hole ground state of the Hubbard-Anderson model, approximated by a variational RVB-type wave function

NARCIS (Netherlands)

Traa, M.R.M.J.; Traa, M.R.M.J.; Caspers, W.J.; Caspers, W.J.; Banning, E.J.; Banning, E.J.

1994-01-01

In this paper the Hubbard-Anderson model on a square lattice with two holes is studied. The ground state (GS) is approximated by a variational RVB-type wave function. The holes interact by exchange of a localized spin excitation (SE), which is created or absorbed if a hole moves to a

Education in astronomy and solar-terrestrial relations in science research environment

Science.gov (United States)

Stoeva, Penka; Stoev, Alexey

2009 -more than 5000 people were happy to observe the Sun, Moon, Venus and other celestial objects; "The Galileoscope"; "Galilean Nights" -encourages everybody to go out to the streets and observe the cosmos; "Dark Skies Awareness" -Measuring of the light pollution level above the region of Stara Zagora; "Astronomy and World Heritage" -archaeoastronomical research of megalithic mon-uments and sanctuaries -examples of ancient observatories for observations of solar extreme rises, sets and meridional culminations; history of the first modern astronomical observatory in Bulgaria; "Galileo Teacher Training Program" -Teaching the teachers. At the beginning of every school year teacher-training course is conducted on astronomy and astrophysics. This year they will actively use telescopes to observe the sky with students; "Universe Awareness" -a lot of games and observations, modeling, exhibitions and parties are organized. "From Earth to the Universe" Exhibitions of astronomical photographs from space and ground based telescopes. Astronomy Olympiads -scientific teaching is improved when the students engaged in doing real science on real data. Fifteen years we participate in the International Astronomy Olympiad and our students win medals. Observarion of solar eclipses is an example of educa-tion in science research environment. We were happy to observe the longest for the last 2000 years total solar eclipse on July 22, 2009, in TianHuangPing, China, at 900m above the sea level. Immediately after the end of this unique phenomenon, images of the eclipsed Sun were sent in Bulgaria. Cooperations -we have good international and national cooperations with a lot of Institutes, Universities, organizations and mass media -radio, TV, magazines, news-papers Information and press conferences about the events have been regularly made available for journalists. With the experience we gained from the IHY and IYA initiatives, being a host of a SID Monitor, we focus on the new International

Gravitational Waves from Gravitational Collapse

Directory of Open Access Journals (Sweden)

Chris L. Fryer

2011-01-01

Full Text Available 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.

Gravitational waves from gravitational collapse

Energy Technology Data Exchange (ETDEWEB)

Fryer, Christopher L [Los Alamos National Laboratory; New, Kimberly C [Los Alamos National Laboratory

2008-01-01

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.

Localization and Broadband Follow-up of the Gravitational-wave Transient GW150914" (2016, ApJL, 826, L13)

Czech Academy of Sciences Publication Activity Database

Abbott, P.B.; Abbott, R.; Abbott, T.D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Jelínek, Martin; Kubánek, Petr; Hudec, René; Caballero-García, María Dolores

2016-01-01

Roč. 826, č. 1 (2016), L13/1-L13/8 ISSN 2041-8205 Institutional support: RVO:67985815 ; RVO:68378271 Keywords : gravitational waves * observational methods * electromagnetic counterparts Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BN - Astronomy, Celestial Mechanics, Astrophysics (FZU-D) Impact factor: 5.522, year: 2016

Mathematical Astronomy in India

Science.gov (United States)

Plofker, Kim

Astronomy in South Asia's Sanskrit tradition, apparently originating in simple calendric computations regulating the timing of ancient ritual practices, expanded over the course of two or three millennia to include detailed spherical models, an endless variety of astrological systems, and academic mathematics in general. Assimilating various technical models, methods, and genres from the astronomy of neighboring cultures, Indian astronomers created new forms that were in turn borrowed by their foreign counterparts. Always recognizably related to the main themes of Eurasian geocentric mathematical astronomy, Indian astral science nonetheless maintained its culturally distinct character until Keplerian heliocentrism and Newtonian mechanics replaced it in colonial South Asia's academic mainstream.

Discovering Astronomy Through Poetry

Science.gov (United States)

Mannone, John C.

2011-05-01

The literature is replete with astronomical references. And much of that literature is poetry. Using this fact, not only can the teacher infuse a new appreciation of astronomy, but also, the student has the opportunity to rediscover history through astronomy. Poetry can be an effective icebreaker in the introduction of new topics in physics and astronomy, as well as a point of conclusion to a lecture. This presentation will give examples of these things from the ancient literature (sacred Hebraic texts), classical literature (Homer's Iliad and Odyssey), traditional poetry (Longfellow, Tennyson and Poe) and modern literature (Frost, Kooser, and others, including the contemporary work of this author).

Waves and particles two essays on fundamental physics

CERN Document Server

Newton, Roger G

2014-01-01

The book consists of two separate parts, the first part is on waves and the second part on particles. In part 1, after describing the awesome power of tsunami and the history of their occurrences, the book turns to the history of explaining phenomena by means of mathematical equations. Then it describes other wave phenomena and the laws governing them: the vibration of strings and drums in musical instruments, the sound waves making them audible, ultrasound and its uses, sonar, and shock waves; electromagnetic waves: light waves, refraction, diffraction, why the sky is blue, the rainbow, and the glory; microwaves and radio waves: radar, radio astronomy, the discovery of the cosmic microwave background radiation, microwave ovens and how a radio works, lasers and masers; waves in modern physics: the Schrödinger wave function and gravitational waves in general relativity; water waves in the ocean, tides and tidal waves, and the quite different solitary waves, solitons discovered in canals. Finally we return to ...

Transmission of Babylonian Astronomy to Other Cultures

Science.gov (United States)

Jones, Alexander

Babylonian astronomy and astrology were extensively transmitted to other civilizations in the second and first millennia BC. Greek astronomy in particular was largely shaped by knowledge of Babylonian observations and mathematical astronomy.

Nebulous networks: Virginia Woolf and popular astronomy

Science.gov (United States)

Henry, Holly Grace

This study investigates Virginia Woolf's fascination with advances in astronomy and telescopic technologies of the 1920s and 30s. Grounded in the cultural studies of science, and the work of theorists such as Donna Haraway and Bruno Latour, the dissertation reconstructs the complex interconnections between Woolf's fiction and prose writing and an explosive popular interest in astronomy and cosmology. Woolf's aesthetic and political practices were shaped by emerging visualization technologies ranging from astronomical telescopes to the hand-held camera. While her writing provides a focus for this investigation, the dissertation offers close readings of fiction and essays by multiple British authors and science writers in the context of these converging phenomena. As a result of glimpsing tiny worlds through her own telescope, Virginia Woolf formulated a global aesthetic and a global politics. Gazing at the moon and stars reminded her that earth is a planet in space, and that earth's inhabitants must rely on this small, fragile globe for their future survival. The opening chapter establishes the cultural context for the study. In 1923, the American astronomer Edwin Hubble determined that the Andromeda galaxy was located far beyond the limits of the Milky Way, then believed to comprise the entire universe. Hubble's radical reconfiguration of the universe contributed to a pervasive sense, in the modern period, of a decentering and re-scaling of humans in the universe. In the chapters that follow, the dissertation offers readings of Woolf's novels and short fiction in relation to her fascination with astronomy and explores how the wildly popular British cosmologist and science writer, Sir James jeans, had a shaping effect on popular culture and on Woolf's narrative practices and pacifist politics. Despite his oblique connections to what became Bloomsbury, jeans and his popular science texts were to play a considerable role in Woolf's formulation of a global aesthetic.

Supplement: "Localization and Broadband Follow-up of the Gravitational-wave Transient GW150914" (2016, ApJL, 826, L13)

Czech Academy of Sciences Publication Activity Database

Abbott, P.B.; Abbott, R.; Abbott, T.D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Jelínek, Martin; Kubánek, Petr; Hudec, René; Caballero-García, María Dolores

2016-01-01

Roč. 225, č. 1 (2016), 8/1-8/15 ISSN 0067-0049 Institutional support: RVO:67985815 ; RVO:68378271 Keywords : gravitational waves * observational methods * electromagnetic counterparts Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics; BN - Astronomy, Celestial Mechanics, Astrophysics (FZU-D) Impact factor: 8.955, year: 2016

Third-World Astronomy Network

Science.gov (United States)

Narlikar, Jayant V.

Several developing countries of the Third World have been actively interested in astronomy, as is evidenced by the membership of the IAU. The enthusiasm of individual astronomers from these countries is, however, not matched by the resources available to them to pursue their interest in astronomy, in teaching as well as research, at an above-threshold level. Major problems requiring solutions are (I) isolation from the mainstream work, which leads to research work which is not quite relevant or realistic, and to teaching based on outdated knowledge; (II) lack of financial resources, leading to shortage of books and journals in the library, insufficient computing power, out-of-date instruments, as well as inability to participate in essential activities like schools, workshops, and major international conferences and symposia; and (III) lack of handson experience with state-of-the-art instrumentation that often leads to good scientists being turned away from astronomical observations towards abstract theories. Experience of the International Centre for Theoretical Physics at Trieste, Italy and of the inter-university centres in India, like the IUCAA at Pune, has shown that limited resources can be made to go a long way by sharing, networking and intelligent use of communications technology. Based on the above experience, this proposal envisages setting up a Third World Astronomy Network (TWAN) under the auspices of the IAU, within the wider ICSU-umbrella with support from the UNESCO as well as participating nations. The TWAN will operate with a few key institutions as local nodal points of a wide network. The objectives of the proposed TWAN and the role of the Nodal Institutions (NIs) are spelled out in this proposal, along with the budgetary support required.

EVALUATION OF CONCEPTUAL FRAMEWORKS IN ASTRONOMY

Directory of Open Access Journals (Sweden)

David Pundak

2016-02-01

Full Text Available Even though astronomy is the oldest science, it is still an open question how to evaluate students’ understanding in astronomy. In spite of the fact that some methods and evaluation tools have been developed for that purpose, the sources of students' difficulties in astronomy are still unclear. This paper presents an investigation of the changes in conceptual frameworks in astronomy among 50 engineering students as a result of learning a general course in astronomy. A special tool called Conceptual Frameworks in Astronomy (CFA, which was initially used in 1989, was adopted to gather data for the present research. In its new version, the tool includes 23 questions and five to six optional answers to each question. Each of the answers characterizes one of the four conceptual frameworks: pre-scientific, geocentric, heliocentric and sidereal. These four conceptual frameworks act as a taxonomical system that enables us to evaluate astronomical understanding. The paper describes the background of the CFA, its development, and discusses its validity and reliability. Using the CFA we were able to: (1 identify the students’ conceptual frameworks at the beginning of the course and at its end, (2 to evaluate the students’ paradigmatic change following the course. It was found that the measure of the students’ improvement (gain index was g = 0.37. Approximately 45% of the students in the course improved their conceptual frameworks in astronomy and 26% deepened their understanding of the heliocentric or sidereal conceptual frameworks. The CFA can also be applied as an evaluation tool in all schools and institutions that teach astronomy.

Europe's Astronomy Teachers Meet at ESO

Science.gov (United States)

1994-12-01

European Association for Astronomy Education Formed A joint EU/ESO Workshop (1) on the Teaching of Astronomy in Europe was held at the ESO Headquarters from November 25-30, 1994, under the auspices of the 1994 European Week for Scientific Culture. More than 100 teachers from secondary schools in 17 European countries participated together with representatives of national ministries and local authorities, as well as professional astronomers. This meeting was the first of its kind ever held and was very successful. As a most visible and immediate outcome, the participants agreed to form the "European Association for Astronomy Education (EAAE)", uniting astronomy educators all over Europe into one network. A provisional Executive Committee of the EAAE was elected which will work towards the organisation of a constitutional conference within the next year. The participants unanimously adopted a "Declaration on the Teaching of Astronomy in Europe", specifying the overall aims and initial actions needed to achieve them. Astronomy: Science, Technology and Culture At the beginning of the Workshop the participants listened to lectures by several specialists about some of the most active fields of astronomy. The scientific sessions included topics as diverse as minor bodies in the solar system, nucleosynthesis, interstellar chemistry and cosmology. Then followed overviews of various recent advances in astronomical technology, some of which are already having direct impact on highly specialized sectors of European industry. They included the advanced use of computers in astronomy, for instance within image processing and data archiving, as well as a demonstration of remote observing. Discussing the cultural aspects, Nigel Calder (UK) and Hubert Reeves (France) emphasized the important role of astronomy in modern society, in particular its continuing influence on our perceptions of mankind's unique location in time and space. Teaching of Astronomy in European Countries

Demographics in Astronomy and Astrophysics

Science.gov (United States)

Ulvestad, James S.

2011-05-01

Astronomy has been undergoing a significant demographic shift over the last several decades, as shown by data presented in the 2000 National Research Council (NRC) report "Federal Funding of Astronomical Research," and the 2010 NRC report, "New Worlds, New Horizons in Astronomy and Astrophysics." For example, the number of advertised postdoctoral positions in astronomy has increased much more rapldly than the number of faculty positions, contributing to a holding pattern of early-career astronomers in multiple postdoctoral positions. This talk will summarize some of the current demographic trends in astronomy, including information about gender and ethnic diversity, and describe some of the possible implications for the future. I thank the members of the Astro2010 Demographics Study Group, as well as numerous white-paper contributors to Astro2010, for providing data and analyses.

Ancient Indian Astronomy in Introductory Texts

Science.gov (United States)

Narahari Achar, B. N.

1997-10-01

It is customary in introductory survey courses in astronomy to devote some time to the history of astronomy. In the available text books only the Greek contribution receives any attention. Apart from Stonehenge and Chichenitza pictures, contributions from Babylon and China are some times mentioned. Hardly any account is given of ancient Indian astronomy. Even when something is mentioned it is incomplete or incorrect or both. Examples are given from several text books currently available. An attempt is made to correct this situation by sketching the contributions from the earliest astronomy of India, namely Vedaanga Jyotisha.

Satellite Based Downward Long Wave Radiation by Various Models in Northeast Asia

Directory of Open Access Journals (Sweden)

Chanyang Sur

2014-01-01

Full Text Available Satellite-based downward long wave radiation measurement under clear sky conditions in Northeast Asia was conducted using five well-known physical models (Brunt 1932, Idso and Jackson 1969, Brutsaert 1975, Satterlund 1979, Prata 1996 with a newly proposed global Rld model (Abramowitz et al. 2012. Data from two flux towers in South Korea were used to validate downward long wave radiation. Moderate resolution imaging spectroradiometer (MODIS atmospheric profile products were used to develop the Rld models. The overall root mean square error (RMSE of MODIS Rld with respect to two ecosystem-type flux towers was determined to be ≈ 20 W m-2. Based on the statistical analyses, MODIS Rld estimates with Brutsaert (1975 and Abramowitz et al. (2012 models were the most applicable for evaluating Rld for clear sky conditions in Northeast Asia. The Abramowitz Rld maps with MODIS Ta and ea showed reasonable seasonal patterns, which were well-aligned with other biophysical variables reported by previous studies. The MODIS Rld map developed in this study will be very useful for identifying spatial patterns that are not detectable from ground-based Rld measurement sites.

Social Representations of the Integrated High School Students about Astronomy

Science.gov (United States)

Barbosa, Jose Isnaldo de Lima; Voelzke, Marcos Rincon

2017-07-01

Astronomy issues are not always adequately handled in the formal education system, as well as, their dissemination in the media is often loaded with sensationalism. However, in this context the students are forming their explanations about it. Therefore, this work has the objective of identifying the possible social representations of students from the Integrated High School on the inductor term Astronomy. It is basically a descriptive research, therefore, a quali-qualitative approach was adopted. The procedures for obtaining the data occurred in the form of a survey, and they involved 653 subjects students from the Integrated High School. The results indicate that the surveyed students have social representations of the object Astronomy, which are based on elements from the formal education space, and also disclosed in the media. In addition, they demonstrate that the students have information about Astronomy, and a value judgment in relation to this science.

The Cost of Astronomy

DEFF Research Database (Denmark)

Dorch, Bertil F.

Using Scopus and national sources, I have investigated the evolution of the cost of publishing in Danish astronomy on a fine scale over a number of years. I find that the number of publications per year from Danish astronomers increased by a factor of four during 15 years: naturally, the correspo......Using Scopus and national sources, I have investigated the evolution of the cost of publishing in Danish astronomy on a fine scale over a number of years. I find that the number of publications per year from Danish astronomers increased by a factor of four during 15 years: naturally......, the corresponding potential cost of publishing must have increased similarly. The actual realized cost of publishing in core journals are investigated for a high profile Danish astronomy research institutions. I argue that the situation is highly unstable if the current cost scenario continues, and I speculate...... that Danish astronomy is risking a scholarly communication collapse due to the combination of increasing subscription cost, increased research output, and increased direct publishing costs related to Open access and other page charges....

New Worlds, New Horizons in Astronomy and Astrophysics

National Research Council Canada - National Science Library

2010-01-01

.... Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysic...

Gravitational wave searches using the DSN (Deep Space Network)

International Nuclear Information System (INIS)

Nelson, S.J.; Armstrong, J.W.

1988-01-01

The Deep Space Network Doppler spacecraft link is currently the only method available for broadband gravitational wave searches in the 0.01 to 0.001 Hz frequency range. The DSN's role in the worldwide search for gravitational waves is described by first summarizing from the literature current theoretical estimates of gravitational wave strengths and time scales from various astrophysical sources. Current and future detection schemes for ground based and space based detectors are then discussed. Past, present, and future planned or proposed gravitational wave experiments using DSN Doppler tracking are described. Lastly, some major technical challenges to improve gravitational wave sensitivities using the DSN are discussed

A DUAL-BAND MILLIMETER-WAVE KINETIC INDUCTANCE CAMERA FOR THE IRAM 30 m TELESCOPE

International Nuclear Information System (INIS)

Monfardini, A.; Benoit, A.; Bideaud, A.; Swenson, L.; Cruciani, A.; Camus, P.; Hoffmann, C.; Desert, F. X.; Doyle, S.; Ade, P.; Mauskopf, P.; Tucker, C.; Roesch, M.; Leclercq, S.; Schuster, K. F.; Endo, A.; Baryshev, A.; Baselmans, J. J. A.; Ferrari, L.; Yates, S. J. C

2011-01-01

The Neel IRAM KIDs Array (NIKA) is a fully integrated measurement system based on kinetic inductance detectors (KIDs) currently being developed for millimeter wave astronomy. The instrument includes dual-band optics allowing simultaneous imaging at 150 GHz and 220 GHz. The imaging sensors consist of two spatially separated arrays of KIDs. The first array, mounted on the 150 GHz branch, is composed of 144 lumped-element KIDs. The second array (220 GHz) consists of 256 antenna-coupled KIDs. Each of the arrays is sensitive to a single polarization; the band splitting is achieved by using a grid polarizer. The optics and sensors are mounted in a custom dilution cryostat, with an operating temperature of ∼70 mK. Electronic readout is realized using frequency multiplexing and a transmission line geometry consisting of a coaxial cable connected in series with the sensor array and a low-noise 4 K amplifier. The dual-band NIKA was successfully tested in 2010 October at the Institute for Millimetric Radio Astronomy (IRAM) 30 m telescope at Pico Veleta, Spain, performing in-line with laboratory predictions. An optical NEP was then calculated to be around 2 x 10 -16 W Hz -1/2 (at 1 Hz) while under a background loading of approximately 4 pW pixel -1 . This improvement in comparison with a preliminary run (2009) verifies that NIKA is approaching the target sensitivity for photon-noise limited ground-based detectors. Taking advantage of the larger arrays and increased sensitivity, a number of scientifically relevant faint and extended objects were then imaged including the Galactic Center SgrB2 (FIR1), the radio galaxy Cygnus A, and the NGC1068 Seyfert galaxy. These targets were all observed simultaneously in the 150 GHz and 220 GHz atmospheric windows.

Design of the iSTAR International STudy on Astronomy Reasoning

Science.gov (United States)

Tatge, Coty B.; Slater, Stephanie J.

2015-01-01

Beginning in 2013, a small international collaborative of discipline-based astronomy education researchers began to build the foundation to start the International STudy on Astronomy Reasoning Project, known simply as iSTAR. The project was a direct result of the inability of existing large international investigations into the learning of science, such as the TIMSS and PISA studies, to provide actionable intelligence on either strengths or weaknesses of astronomy teaching across the world. This is not because those studies were flawed; rather, they focused on the general characteristics of teaching and learning across all sciences. Prior to the iSTAR effort, there has been no systematic effort to measure individual's conceptual astronomy understanding across the globe. The goal of studying a widely dispersed international sample is to identify cultural subpopulations that do not conform to our existing knowledge of student misconceptions, highlighting unexpected cultural or educational practices that hint at alternative, and perhaps more effective, means of instruction. As a first step, we are carefully translating the Test Of Astronomy STandards - TOAST multiple-choice assessment instrument and carefully attending to nuances that occur during the translation process as cultural clues to differences in the teaching and learning of astronomy. We are actively welcoming and seeking international partners in this work through the CAPERteam.com website and at https://www.surveymonkey.com/s/iSTAR-Registration . This project is sponsored and managed by the CAPER Center for Astronomy & Physics Education Research in collaboration with members of the International Astronomical Union-Commission 46.

Rescuing Middle School Astronomy

Science.gov (United States)

Mayo, L. A.; Janney, D.

2010-12-01

There is a crisis in education at the middle school level (Spellings, 2006). Recent studies point to large disparities in middle school performance in schools with high minority populations. The largest disparities exist in areas of math and science. Astronomy has a universal appeal for K-12 students but is rarely taught at the middle school level. When it is taught at all it is usually taught in isolation with few references in other classes such as other sciences (e.g. physics, biology, and chemistry), math, history, geography, music, art, or English. The problem is greatest in our most challenged school districts. With scores in reading and math below national averages in these schools and with most state achievement tests ignoring subjects like astronomy, there is little room in the school day to teach about the world outside our atmosphere. Add to this the exceedingly minimal training and education in astronomy that most middle school teachers have and it is a rare school that includes any astronomy teaching at all. In this presentation, we show how to develop and offer an astronomy education training program for middle school teachers encompassing a wide range of educational disciplines that are frequently taught at the middle school level. The prototype for this program was developed and launched in two of the most challenged and diverse school systems in the country; D.C. Public Schools, and Montgomery County (MD) Public Schools.

Use of ground-based wind profiles in mesoscale forecasting

Science.gov (United States)

Schlatter, Thomas W.

1985-01-01

A brief review is presented of recent uses of ground-based wind profile data in mesoscale forecasting. Some of the applications are in real time, and some are after the fact. Not all of the work mentioned here has been published yet, but references are given wherever possible. As Gage and Balsley (1978) point out, sensitive Doppler radars have been used to examine tropospheric wind profiles since the 1970's. It was not until the early 1980's, however, that the potential contribution of these instruments to operational forecasting and numerical weather prediction became apparent. Profiler winds and radiosonde winds compare favorably, usually within a few m/s in speed and 10 degrees in direction (see Hogg et al., 1983), but the obvious advantage of the profiler is its frequent (hourly or more often) sampling of the same volume. The rawinsonde balloon is launched only twice a day and drifts with the wind. In this paper, I will: (1) mention two operational uses of data from a wind profiling system developed jointly by the Wave Propagation and Aeronomy Laboratories of NOAA; (2) describe a number of displays of these same data on a workstation for mesoscale forecasting developed by the Program for Regional Observing and Forecasting Services (PROFS); and (3) explain some interesting diagnostic calculations performed by meteorologists of the Wave Propagation Laboratory.

Modern Publishing Approach of Journal of Astronomy & Earth Sciences Education

Science.gov (United States)

Slater, Timothy F.

2015-01-01

Filling a needed scholarly publishing avenue for astronomy education researchers and earth science education researchers, the Journal of Astronomy & Earth Sciences Education - JAESE published its first volume and issue in 2014. The Journal of Astronomy & Earth Sciences Education - JAESE is a scholarly, peer-reviewed scientific journal publishing original discipline-based education research and evaluation, with an emphasis of significant scientific results derived from ethical observations and systematic experimentation in science education and evaluation. International in scope, JAESE aims to publish the highest quality and timely articles from discipline-based education research that advance understanding of astronomy and earth sciences education and are likely to have a significant impact on the discipline or on policy. Articles are solicited describing both (i) systematic science education research and (ii) evaluated teaching innovations across the broadly defined Earth & space sciences education, including the disciplines of astronomy, climate education, energy resource science, environmental science, geology, geography, agriculture, meteorology, planetary sciences, and oceanography education. The publishing model adopted for this new journal is open-access and articles appear online in GoogleScholar, ERIC, and are searchable in catalogs of 440,000 libraries that index online journals of its type. Rather than paid for by library subscriptions or by society membership dues, the annual budget is covered by page-charges paid by individual authors, their institutions, grants or donors: This approach is common in scientific journals, but is relatively uncommon in education journals. Authors retain their own copyright. The journal is owned by the Clute Institute of Denver, which owns and operates 17 scholarly journals and currently edited by former American Astronomical Society Education Officer Tim Slater, who is an endowed professor at the University of Wyoming and

Grote Reber, Radio Astronomy Pioneer, Dies

Science.gov (United States)

2002-12-01

something of a minor tourist attraction, he later recalled. Using electronics he designed and built that pushed the technical capabilities of the era, Reber succeeded in detecting "cosmic static" in 1939. In 1941, Reber produced the first radio map of the sky, based on a series of systematic observations. His radio-astronomy work continued over the next several years. Though not a professional scientist, his research results were published in a number of prestigious technical journals, including Nature, the Astrophysical Journal, the Proceedings of the Institute of Radio Engineers and the Journal of Geophysical Research. Reber also received a number of honors normally reserved for scientists professionally trained in astronomy, including the American Astronomical Society's Henry Norris Russell Lectureship and the Astronomical Society of the Pacific's Bruce Medal in 1962, the National Radio Astronomy Observatory's Jansky Lectureship in 1975, and the Royal Astronomical Society's Jackson-Gwilt Medal in 1983. Reber's original dish antenna now is on display at the National Radio Astronomy Observatory's site in Green Bank, West Virginia, where Reber worked in the late 1950s. All of his scientific papers and records as well as his personal and scientific correspondence are held by the NRAO, and will be exhibited in the observatory's planned new library in Charlottesville, Virginia. Reber's amateur-radio callsign, W9GFZ, is held by the NRAO Amateur Radio Club. This callsign was used on the air for the first time since the 1930s on August 25, 2000, to mark the dedication of the Robert C. Byrd Green Bank Telescope. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Gravitational Waves from Gravitational Collapse.

Science.gov (United States)

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.

Music and Astronomy Under the Stars 2009

Science.gov (United States)

Lubowich, D.

2010-08-01

Bring telescopes to where the people are! Music and Astronomy Under the Stars is a three-year NASA-funded astronomy outreach program at community parks during and after music concerts and outdoor family events—such as a Halloween Stars-Spooky Garden Walk. While there have been many astronomy outreach activities and telescope observations at city sidewalks and parks, this program targets a completely different audience: music lovers who are attending summer concerts held in community parks. These music lovers who may never have visited a science museum, planetarium, or star party are exposed to telescope observations and astronomy information with no additional travel costs. Music and Astronomy Under the Stars increased awareness, engagement, and interest in astronomy at classical, pop, rock, and ethnic music concerts. This program includes solar observing before the concerts, telescope observations including a live image projection system, an astronomical video presentation, and astronomy banners/posters. Approximately 500-16,000 people attended each event and 25% to 50% of the people at each event participated in the astronomy program. This program also reached underrepresented and underserved groups (women, minorities, older adults). The target audience (Nassau and Suffolk Counties, New York) is 2,900,000 people, which is larger than combined population of Atlanta, Boston, Denver, Minneapolis, and San Francisco. Although eleven events were planned in 2009, two were canceled due to rain and our largest event, the NY Philharmonic in the Park (attended by 67,000 people in 2008), was cancelled for financial reasons. Our largest event in 2009 was the Tanglewood Music Festival, Lenox MA, attended by 16,000 people where over 5000 people participated in astronomy activities. The Amateur Observers' Society of New York assisted with the NY concerts and the Springfield STARS astronomy club assisted at Tanglewood. In 2009 over 15,000 people participated in astronomy

Chaco astronomies

Science.gov (United States)

Martín López, Alejandro

2015-08-01

This presentation discusses the result of 18 years of ethnographic and ethnohistorical studies on Chaco astronomies. The main features of the systems of astronomical knowledge of the Chaco Aboriginal groups will be discussed. In particular we will discuss the relevance of the Milky Way, the role of the visibility of the Pleiades, the ways in which the celestial space is represented, the constitution of astronomical orientations in geographic space, etc. We also address a key feature of their vision of the cosmos: the universe is seen by these groups as a socio-cosmos, where humans and non-humans are related. These are therefore actually socio-cosmologies. We will link this to the theories of Chaco Aboriginal groups about power and political relations.We will discuss how the study of Aboriginal astronomies must be performed along with the studies about astronomies of Creole people and European migrants, as well as anthropological studies about the science teaching in the formal education system and by the mass media. In this form we will discuss the relevance of a very complex system of interethnic relations for the conformation of these astronomical representations and practices.We will also discuss the general methodological implications of this case for the ethnoastronomy studies. In particular we will talk about the advantages of a study of regional scope and about the key importance of put in contact the ethnoastronomy with contemporary issues in social sciences.We also analyze the importance of ethnoastronomy studies in relation to studies of sociology of science, especially astronomy. We also study the potential impact on improving formal and informal science curricula and in shaping effective policies to protect the tangible and intangible astronomical heritage in a context of respect for the rights of Aboriginal groups.

Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

International Nuclear Information System (INIS)

Wetovsky, Marvin A.; Patterson, Eileen F.; Sandoval, Marisa N.

2011-01-01

These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Energy Technology Data Exchange (ETDEWEB)

Wetovsky, Marvin A. [Editor; Patterson, Eileen F. [Editor; Sandoval, Marisa N. [Editor

2011-09-13

These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring

Energy Technology Data Exchange (ETDEWEB)

Wetovsky, Marv A [Los Alamos National Laboratory; Aguilar-chang, Julio [Los Alamos National Laboratory; Arrowsmith, Marie [Los Alamos National Laboratory; Arrowsmith, Stephen [Los Alamos National Laboratory; Baker, Diane [Los Alamos National Laboratory; Begnaud, Michael [Los Alamos National Laboratory; Harste, Hans [Los Alamos National Laboratory; Maceira, Monica [Los Alamos National Laboratory; Patton, Howard [Los Alamos National Laboratory; Phillips, Scott [Los Alamos National Laboratory; Randall, George [Los Alamos National Laboratory; Revelle, Douglas [Los Alamos National Laboratory; Rowe, Charlotte [Los Alamos National Laboratory; Stead, Richard [Los Alamos National Laboratory; Steck, Lee [Los Alamos National Laboratory; Whitaker, Rod [Los Alamos National Laboratory; Yang, Xiaoning [Los Alamos National Laboratory

2008-09-23

These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Energy Technology Data Exchange (ETDEWEB)

Wetovsky, Marvin A [Editor; Patterson, Eileen F [Editor

2010-09-21

These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Proceedings of the 2009 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

Energy Technology Data Exchange (ETDEWEB)

Wetovsky, Marv A [Los Alamos National Laboratory; Aguilar - Chang, Julio [Los Alamos National Laboratory; Anderson, Dale [Los Alamos National Laboratory; Arrowsmith, Marie [Los Alamos National Laboratory; Arrowsmith, Stephen [Los Alamos National Laboratory; Baker, Diane [Los Alamos National Laboratory; Begnaud, Michael [Los Alamos National Laboratory; Harste, Hans [Los Alamos National Laboratory; Maceira, Monica [Los Alamos National Laboratory; Patton, Howard [Los Alamos National Laboratory; Phillips, Scott [Los Alamos National Laboratory; Randall, George [Los Alamos National Laboratory; Rowe, Charlotte [Los Alamos National Laboratory; Stead, Richard [Los Alamos National Laboratory; Steck, Lee [Los Alamos National Laboratory; Whitaker, Rod [Los Alamos National Laboratory; Yang, Xiaoning ( David ) [Los Alamos National Laboratory

2009-09-21

These proceedings contain papers prepared for the Monitoring Research Review 2009: Ground -Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2009 in Tucson, Arizona,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Test Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

International Nuclear Information System (INIS)

Wetovsky, Marvin A.; Patterson, Eileen F.

2010-01-01

These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

Earthquake ground-motion in presence of source and medium heterogeneities

KAUST Repository

Vyas, Jagdish Chandra

2017-01-01

This dissertation work investigates the effects of earthquake rupture complexity and heterogeneities in Earth structure on near-field ground-motions. More specifically, we address two key issues in seismology: (1) near-field ground-shaking variability as function of distance and azimuth for unilateral directive ruptures, and (2) impact of rupture complexity and seismic scattering on Mach wave coherence associated with supershear rupture propagation. We examine earthquake ground-motion variability associated with unilateral ruptures based on ground-motion simulations of the MW 7.3 1992 Landers earthquake, eight simplified source models, and a MW 7.8 rupture simulation (ShakeOut) for the San Andreas fault. Our numerical modeling reveals that the ground-shaking variability in near-fault distances (< 20 km) is larger than that given by empirical ground motion prediction equations. In addition, the variability decreases with increasing distance from the source, exhibiting a power-law decay. The high near-field variability can be explained by strong directivity effects whose influence weaken as we move away from the fault. At the same time, the slope of the power-law decay is found to be dominantly controlled by slip heterogeneity. Furthermore, the ground-shaking variability is high in the rupture propagation direction whereas low in the directions perpendicular to it. However, the variability expressed as a function of azimuth is not only sensitive to slip heterogeneity, but also to rupture velocity. To study Mach wave coherence for supershear ruptures, we consider heterogeneities in rupture parameters (variations in slip, rise time and rupture speed) and 3D scattering media having small-scale random heterogeneities. The Mach wave coherence is reduced at near-fault distances (< 10 km) by the source heterogeneities. At the larger distances from the source, medium scattering plays the dominant role in reducing the Mach wave coherence. Combined effect of the source and

Multi-Institutional Collaborative Astronomy Education Research

Science.gov (United States)

Slater, T. F.; Slater, S. J.

2011-09-01

ASP, AAS, APS, and AAPT advocate that scientists should be engaged and acknowledged for successfully engaging in astronomy and physics education research and the scholarship of teaching because these efforts serve to improve pedagogical techniques and the evaluation of teaching. However, scientists have had the opportunity to pursue formal training in how to meaningfully engage in astronomy education research as an important scholarly endeavor. This special interest session for college and university physics and astronomy faculty, post-docs, and graduate students provided a forum to discuss the motivations, strategies, methodology, and publication routes for improving astronomy education through conducting rigorous science education research. Topics for discussion targeted the value of various education research questions, strengths and weaknesses of several different research design methodologies, strategies to successfully obtain Institutional Review Board approval to conduct education research on human subjects, and become more aware of how education research articles are created for publication in journals such as the Astronomy Education Review.

Highlighting the History of Astronomy in the Asia-Pacific Region

CERN Document Server

Nakamura, Tsuko; Strom, Richard G; ICOA-6 Conference

2011-01-01

This book provides readers with the results of recent research from some of the world's leading historians of astronomy on aspects of Arabic, Australian, Chinese, Japanese, and North and South American astronomy and astrophysics. It contains peer-reviewed papers gathered from the International Conferences on Oriental Astronomy 6 (ICO-6) with the chosen theme of "Highlighting the History of Astronomy in the Asia-Pacific Region." Of particular note are the sections on Arabic astronomy, Asian applied astronomy and the history of Australian radio astronomy, and the chapter on Peruvian astronomy. This title is a valuable complement for those with research interests in applied historical astronomy; archaeoastronomy; calendars, manuscripts, and star charts; historical instruments and observatories, and the history of radio astronomy.

Astronomy Week in Madeira, Portugal

Science.gov (United States)

Augusto, P.; Sobrinho, J. L.

2012-05-01

The outreach programme Semanas da Astronomia (Astronomy Weeks) is held in late spring or summer on the island of Madeira, Portugal. This programme has been attracting enough interest to be mentioned in the regional press/TV/radio every year and is now, without doubt, the astronomical highlight of the year on Madeira. We believe that this programme is a good case study for showing how to attract the general public to astronomy in a small (population 250 000, area 900 km2) and fairly isolated place such as Madeira. Our Astronomy Weeks have been different each year and have so far included exhibitions, courses, talks, a forum, documentaries, observing sessions (some with blackouts), music and an astro party. These efforts may contribute towards putting Madeira on the map with respect to observational astronomy, and have also contributed to the planned installation of two observatories in the island.

Analysis of Different Methods for Wave Generation and Absorption in a CFD-Based Numerical Wave Tank

Directory of Open Access Journals (Sweden)

Adria Moreno Miquel

2018-06-01

Full Text Available In this paper, the performance of different wave generation and absorption methods in computational fluid dynamics (CFD-based numerical wave tanks (NWTs is analyzed. The open-source CFD code REEF3D is used, which solves the Reynolds-averaged Navier–Stokes (RANS equations to simulate two-phase flow problems. The water surface is computed with the level set method (LSM, and turbulence is modeled with the k-ω model. The NWT includes different methods to generate and absorb waves: the relaxation method, the Dirichlet-type method and active wave absorption. A sensitivity analysis has been conducted in order to quantify and compare the differences in terms of absorption quality between these methods. A reflection analysis based on an arbitrary number of wave gauges has been adopted to conduct the study. Tests include reflection analysis of linear, second- and fifth-order Stokes waves, solitary waves, cnoidal waves and irregular waves generated in an NWT. Wave breaking over a sloping bed and wave forces on a vertical cylinder are calculated, and the influence of the reflections on the wave breaking location and the wave forces on the cylinder is investigated. In addition, a comparison with another open-source CFD code, OpenFOAM, has been carried out based on published results. Some differences in the calculated quantities depending on the wave generation and absorption method have been observed. The active wave absorption method is seen to be more efficient for long waves, whereas the relaxation method performs better for shorter waves. The relaxation method-based numerical beach generally results in lower reflected waves in the wave tank for most of the cases simulated in this study. The comparably better performance of the relaxation method comes at the cost of larger computational requirements due to the relaxation zones that have to be included in the domain. The reflections in the NWT in REEF3D are generally lower than the published results for

Gravitational waves from instabilities in relativistic stars

International Nuclear Information System (INIS)

Andersson, Nils

2003-01-01

This paper provides an overview of stellar instabilities as sources of gravitational waves. The aim is to put recent work on secular and dynamical instabilities in compact stars in context, and to summarize the current thinking about the detectability of gravitational waves from various scenarios. As a new generation of kilometre length interferometric detectors is now coming online this is a highly topical theme. The review is motivated by two key questions for future gravitational-wave astronomy: are the gravitational waves from various instabilities detectable? If so, what can these gravitational-wave signals teach us about neutron star physics? Even though we may not have clear answers to these questions, recent studies of the dynamical bar-mode instability and the secular r-mode instability have provided new insights into many of the difficult issues involved in modelling unstable stars as gravitational-wave sources. (topical review)

Illumination compensation in ground based hyperspectral imaging

Science.gov (United States)

Wendel, Alexander; Underwood, James

2017-07-01

Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

Water vapor estimation using digital terrestrial broadcasting waves

Science.gov (United States)

Kawamura, S.; Ohta, H.; Hanado, H.; Yamamoto, M. K.; Shiga, N.; Kido, K.; Yasuda, S.; Goto, T.; Ichikawa, R.; Amagai, J.; Imamura, K.; Fujieda, M.; Iwai, H.; Sugitani, S.; Iguchi, T.

2017-03-01

A method of estimating water vapor (propagation delay due to water vapor) using digital terrestrial broadcasting waves is proposed. Our target is to improve the accuracy of numerical weather forecast for severe weather phenomena such as localized heavy rainstorms in urban areas through data assimilation. In this method, we estimate water vapor near a ground surface from the propagation delay of digital terrestrial broadcasting waves. A real-time delay measurement system with a software-defined radio technique is developed and tested. The data obtained using digital terrestrial broadcasting waves show good agreement with those obtained by ground-based meteorological observation. The main features of this observation are, no need for transmitters (receiving only), applicable wherever digital terrestrial broadcasting is available and its high time resolution. This study shows a possibility to estimate water vapor using digital terrestrial broadcasting waves. In the future, we will investigate the impact of these data toward numerical weather forecast through data assimilation. Developing a system that monitors water vapor near the ground surface with time and space resolutions of 30 s and several kilometers would improve the accuracy of the numerical weather forecast of localized severe weather phenomena.

A Community - Centered Astronomy Research Program

Science.gov (United States)

Boyce, Pat; Boyce, Grady

2017-06-01

The Boyce Research Initiatives and Education Foundation (BRIEF) is providing semester-long, hands-on, astronomy research experiences for students of all ages that results in their publishing peer-reviewed papers. The course in astronomy and double star research has evolved from a face-to-face learning experience with two instructors to an online - hybrid course that simultaneously supports classroom instruction at a variety of schools in the San Diego area. Currently, there are over 65 students enrolled in three community colleges, seven high schools, and one university as well as individual adult learners. Instructional experience, courseware, and supporting systems were developed and refined through experience gained in classroom settings from 2014 through 2016. Topics of instruction include Kepler's Laws, basic astrometry, properties of light, CCD imaging, use of filters for varying stellar spectral types, and how to perform research, scientific writing, and proposal preparation. Volunteer instructors were trained by taking the course and producing their own research papers. An expanded program was launched in the fall semester of 2016. Twelve papers from seven schools were produced; eight have been accepted for publication by the Journal of Double Observations (JDSO) and the remainder are in peer review. Three additional papers have been accepted by the JDSO and two more are in process papers. Three college professors and five advanced amateur astronomers are now qualified volunteer instructors. Supporting tools are provided by a BRIEF server and other online services. The server-based tools range from Microsoft Office and planetarium software to top-notch imaging programs and computational software for data reduction for each student team. Observations are performed by robotic telescopes worldwide supported by BRIEF. With this success, student demand has increased significantly. Many of the graduates of the first semester course wanted to expand their

Indian Astronomy: History of

Science.gov (United States)

Mercier, R.; Murdin, P.

2002-01-01

From the time of A macronryabhat under dota (ca AD 500) there appeared in India a series of Sanskrit treatises on astronomy. Written always in verse, and normally accompanied by prose commentaries, these served to create an Indian tradition of mathematical astronomy which continued into the 18th century. There are as well texts from earlier centuries, grouped under the name Jyotishaveda macronn d...

Astronomy for teachers: A South African Perspective

Science.gov (United States)

de Witt, Aletha; West, Marion; Leeuw, Lerothodi; Gouws, Eldrie

2015-08-01

South Africa has nominated Astronomy as a “flagship science” and aims to be an international Astronomy hub through projects such as the Square Kilometre Array (SKA) and the South African Large Telescope (SALT). These projects open up career opportunities in maths, science and engineering and therefore offers a very real door for learners to enter into careers in science and technology through Astronomy. However, the Trends in International Mathematics and Science Survey (TIMSS), the Global Competitiveness Report (GCR) and Annual National Assessment (ANA) have highlighted that South Africa’s Science and Mathematics education is in a critical condition and that South African learners score amongst the worst in the world in both these subjects. In South Africa Astronomy is generally regarded as the worst taught and most avoided Natural Science knowledge strand, and most teachers that specialised in Natural Sciences, never covered Astronomy in their training.In order to address these issues a collaborative project between the University of South Africa (UNISA) and the Hartebeesthoek Radio Astronomy Observatory (HartRAO) was initiated, which aims to assist teachers to gain more knowledge and skills so that they can teach Astronomy with confidence. By collaborating we aim to ensure that the level of astronomy development will be raised in both South Africa and the rest of Africa.With the focus on Teaching and Learning, the research was conducted within a quantitative paradigm and 600 structured questionnaires were administered to Natural Science teachers in Public primary schools in Gauteng, South Africa. This paper reports the findings of this research and makes recommendations on how to assist teachers to teach Astronomy with confidence.

Near-fault earthquake ground motion prediction by a high-performance spectral element numerical code

International Nuclear Information System (INIS)

Paolucci, Roberto; Stupazzini, Marco

2008-01-01

Near-fault effects have been widely recognised to produce specific features of earthquake ground motion, that cannot be reliably predicted by 1D seismic wave propagation modelling, used as a standard in engineering applications. These features may have a relevant impact on the structural response, especially in the nonlinear range, that is hard to predict and to be put in a design format, due to the scarcity of significant earthquake records and of reliable numerical simulations. In this contribution a pilot study is presented for the evaluation of seismic ground-motions in the near-fault region, based on a high-performance numerical code for 3D seismic wave propagation analyses, including the seismic fault, the wave propagation path and the near-surface geological or topographical irregularity. For this purpose, the software package GeoELSE is adopted, based on the spectral element method. The set-up of the numerical benchmark of 3D ground motion simulation in the valley of Grenoble (French Alps) is chosen to study the effect of the complex interaction between basin geometry and radiation mechanism on the variability of earthquake ground motion

Bringing Live Astronomy into the Classroom and to the Public

Science.gov (United States)

Cox, Paul

2017-01-01

Slooh makes astronomy incredibly easy, engaging and affordable for anyone with a desire to explore and study the cosmos for themselves. Since 2003 Slooh has connected telescopes to the Internet for access by the public, schools and colleges. Slooh’s fully robotic observatories process FITS data in real-time for broadcast to the Internet. Slooh’s technology is protected by Patent No.: US 7,194,146 B2 which was awarded in 2006.Slooh members have taken over 6-million images of over 50,000 celestial objects, participated in research with leading astronomical institutions, and made over 6,000 Near-Earth Object submissions to the Minor Planet Center. They were also the major contributor of ground based observations of comet 67P/Churyumov-Gerasimenko to the ESA Pro-Am campaign during the Rosetta mission.Slooh’s flagship observatories are located at the Observatorio del Teide, in partnership with the Institute of Astrophysics of the Canary Islands (IAC), and in Chile, in partnership with the Pontificia Universidad Católica de Chile.Slooh’s free live broadcasts of celestial events and phenomena, including eclipses, solar activity, NEAs, comets, lunar cycles, etc. feature narration by astronomy experts Paul Cox and Bob Berman, and are syndicated to media outlets worldwide.Currently in beta, the new "Slooh Classroom" program is due to launch in Q1 2017. This pairs participating schools in the USA to schools in Africa to collaborate on lesson plans that incorporate the use of Slooh's telescopes live in-class.

Indian Mathematics and Astronomy: Some Land- marks

Indian Academy of Sciences (India)

mathematics and astronomy from the ... tion of the Indian contribution to math- .... only 16 years to go before Whish's re- ... which is based on the recent paper of ... The last chapter of this book is dedi- ... interesting, though elementary, exam-.

The Inwood Astronomy Project: Ready for IYA 2009

Science.gov (United States)

Shilling Kendall, Jason

2009-01-01

The Inwood Astronomy Project begins its mission of "100 Nights of Astronomy", an outreach program for the IYA 2009 in New York City. While the city lights may at first glance be a major deterrent to amateur and educational night-sky viewing, the author describes numerous community-based initiatives designed to fit into a racially and ethnically diverse neighborhood of Northern Manhattan and the Bronx, which all give a deeper understanding and appreciation of and for the night sky. The author presents ways for professional astronomers to use their light-polluted cities and towns for the same purpose.

Black-Hole Binaries, Gravitational Waves, and Numerical Relativity

Science.gov (United States)

Kelly, Bernard J.; Centrella, Joan; Baker, John G.; Kelly, Bernard J.; vanMeter, James R.

2010-01-01

Understanding the predictions of general relativity for the dynamical interactions of two black holes has been a long-standing unsolved problem in theoretical physics. Black-hole mergers are monumental astrophysical events ' releasing tremendous amounts of energy in the form of gravitational radiation ' and are key sources for both ground- and spacebased gravitational wave detectors. The black-hole merger dynamics and the resulting gravitational waveforms can only he calculated through numerical simulations of Einstein's equations of general relativity. For many years, numerical relativists attempting to model these mergers encountered a host of problems, causing their codes to crash after just a fraction of a binary orbit cnuld be simulated. Recently ' however, a series of dramatic advances in numerical relativity has ' for the first time, allowed stable / robust black hole merger simulations. We chronicle this remarkable progress in the rapidly maturing field of numerical relativity, and the new understanding of black-hole binary dynamics that is emerging. We also discuss important applications of these fundamental physics results to astrophysics, to gravitationalwave astronomy, and in other areas.

Artillery localization using networked wireless ground sensors

Science.gov (United States)

Swanson, David C.

2002-08-01

This paper presents the results of an installation of four acoustic/seismic ground sensors built using COTS computers and networking gear and operating on a continuous basis at Yuma Proving Grounds, Arizona. A description of the design can be found as well, which is essentially a Windows 2000 PC with 24-bit data acquisition, GPS timing, and environmental sensors for wind and temperature. A 4-element square acoustic array 1.8m on a side can be used to detect the time and angle of arrival of the muzzle blast and the impact explosion. A 3-component geophone allows the seismic wave direction to be estimated. The 8th channel of the 24-bit data acquisition system has a 1-pulse-per-second time signal from the GPS. This allows acoustic/seismic 'snapshots' to be coherently related from multiple disconnected ground sensor nodes. COTS 2.4 GHz frequency hopping radios (802.11 standard) are used with either omni or yagi antennas depending on the location on the range. Localization of the artillery or impact can be done by using the time and angle of arrival of the waves at 2 or more ground sensor locations. However, this straightforward analysis can be significantly complicated by weather and wind noise and is also the subject of another research contract. This work will present a general description of the COTS ground sensor installation, show example data autonomously collected including agent-based atmospheric data, and share some of the lessons learned from operating a Windows 2000 based system continuously outdoors.

Cultural Astronomy in the Armenian Highland

Science.gov (United States)

Farmanyan, S. V.; Suvaryan, Yu. M.; Mickaelian, A. M. (Eds.)

2016-12-01

The book contains 29 articles of the Proceedings of the Young Scientists Conference "Cultural Astronomy in the Armenian Highland" held at the Armenian National Academy of Sciences on 20-23 June 2016. It consists of 4 main sections: "Introductory", "Cultural Astronomy", "Archaeoastronomy", "Scientific Tourism and Journalism, Astronomical Education and Amateur Astronomy". The book may be interesting to astronomers, culturologists, philologists, linguists, historians, archaeologists, art historians, ethnographers and to other specialists, as well as to students.

Modeling of Ground Deformation and Shallow Surface Waves Generated by Martian Dust Devils and Perspectives for Near-Surface Structure Inversion

Science.gov (United States)

Kenda, Balthasar; Lognonné, Philippe; Spiga, Aymeric; Kawamura, Taichi; Kedar, Sharon; Banerdt, William Bruce; Lorenz, Ralph; Banfield, Don; Golombek, Matthew

2017-10-01

We investigated the possible seismic signatures of dust devils on Mars, both at long and short period, based on the analysis of Earth data and on forward modeling for Mars. Seismic and meteorological data collected in the Mojave Desert, California, recorded the signals generated by dust devils. In the 10-100 s band, the quasi-static surface deformation triggered by pressure fluctuations resulted in detectable ground-tilt effects: these are in good agreement with our modeling based on Sorrells' theory. In addition, high-frequency records also exhibit a significant excitation in correspondence to dust devil episodes. Besides wind noise, this signal includes shallow surface waves due to the atmosphere-surface coupling and is used for a preliminary inversion of the near-surface S-wave profile down to 50 m depth. In the case of Mars, we modeled the long-period signals generated by the pressure field resulting from turbulence-resolving Large-Eddy Simulations. For typical dust-devil-like vortices with pressure drops of a couple Pascals, the corresponding horizontal acceleration is of a few nm/s2 for rocky subsurface models and reaches 10-20 nm/s2 for weak regolith models. In both cases, this signal can be detected by the Very-Broad Band seismometers of the InSight/SEIS experiment up to a distance of a few hundred meters from the vortex, the amplitude of the signal decreasing as the inverse of the distance. Atmospheric vortices are thus expected to be detected at the InSight landing site; the analysis of their seismic and atmospheric signals could lead to additional constraints on the near-surface structure, more precisely on the ground compliance and possibly on the seismic velocities.

Focusing Leaky Waves: A Class of Electromagnetic Localized Waves with Complex Spectra

Science.gov (United States)

Fuscaldo, Walter; Comite, Davide; Boesso, Alessandro; Baccarelli, Paolo; Burghignoli, Paolo; Galli, Alessandro

2018-05-01

Localized waves, i.e., the wide class of limited-diffraction, limited-dispersion solutions to the wave equation are generally characterized by real wave numbers. We consider the role played by localized waves with generally complex "leaky" wave numbers. First, the impact of the imaginary part of the wave number (i.e., the leakage constant) on the diffractive (spatial broadening) features of monochromatic localized solutions (i.e., beams) is rigorously evaluated. Then general conditions are derived to show that only a restricted class of spectra (either real or complex) allows for generating a causal localized wave. It turns out that backward leaky waves fall into this category. On this ground, several criteria for the systematic design of wideband radiators, namely, periodic radial waveguides based on backward leaky waves, are established in the framework of leaky-wave theory. An effective design method is proposed to minimize the frequency dispersion of the proposed class of devices and the impact of the "leakage" on the dispersive (temporal broadening) features of polychromatic localized solutions (i.e., pulses) is accounted for. Numerical results corroborate the concept, clearly highlighting the advantages and limitations of the leaky-wave approach for the generation of localized pulses at millimeter-wave frequencies, where energy focusing is in high demand in modern applications.

Image-based deep learning for classification of noise transients in gravitational wave detectors

Science.gov (United States)

Razzano, Massimiliano; Cuoco, Elena

2018-05-01

The detection of gravitational waves has inaugurated the era of gravitational astronomy and opened new avenues for the multimessenger study of cosmic sources. Thanks to their sensitivity, the Advanced LIGO and Advanced Virgo interferometers will probe a much larger volume of space and expand the capability of discovering new gravitational wave emitters. The characterization of these detectors is a primary task in order to recognize the main sources of noise and optimize the sensitivity of interferometers. Glitches are transient noise events that can impact the data quality of the interferometers and their classification is an important task for detector characterization. Deep learning techniques are a promising tool for the recognition and classification of glitches. We present a classification pipeline that exploits convolutional neural networks to classify glitches starting from their time-frequency evolution represented as images. We evaluated the classification accuracy on simulated glitches, showing that the proposed algorithm can automatically classify glitches on very fast timescales and with high accuracy, thus providing a promising tool for online detector characterization.

Investigation on the real-time prediction of ground motions using seismic records observed in deep boreholes

Science.gov (United States)

Miyakoshi, H.; Tsuno, S.

2013-12-01

The present method of the EEW system installed in the railway field of Japan predicts seismic ground motions based on the estimated earthquake information about epicentral distances and magnitudes using initial P-waves observed on the surface. In the case of local earthquakes beneath the Tokyo Metropolitan Area, however, a method to directly predict seismic ground motions using P-waves observed in deep boreholes could issue EEWs more simply and surely. Besides, a method to predict seismic ground motions, using S-waves observed in deep boreholes and S-wave velocity structures beneath seismic stations, could show planar distributions of ground motions for train operation control areas in the aftermath of earthquakes. This information is available to decide areas in which the emergency inspection of railway structures should be performed. To develop those two methods, we investigated relationships between peak amplitudes on the surface and those in deep boreholes, using seismic records of KiK-net stations in the Kanto Basin. In this study, we used earthquake accelerograms observed in boreholes whose depths are deeper than the top face of Pre-Neogene basement and those on the surface at 12 seismic stations of KiK-net. We selected 243 local earthquakes whose epicenters are located around the Kanto Region. Those JMA magnitudes are in the range from 4.5 to 7.0. We picked the on-set of P-waves and S-waves using a vertical component and two horizontal components, respectively. Peak amplitudes of P-waves and S-waves were obtained using vertical components and vector sums of two horizontal components, respectively. We estimated parameters which represent site amplification factors beneath seismic stations, using peak amplitudes of S-waves observed in the deep borehole and those on the surface, to minimize the residuals between calculations by the theoretical equation and observations. Correlation coefficients between calculations and observations are high values in the range

Japanese space gravitational wave antenna DECIGO and DPF

Science.gov (United States)

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.

Book Review: Astronomy: A Self-Teaching Guide, 6th Edition

Science.gov (United States)

Marigza, R. N., Jr.

2009-03-01

The sixth edition of Moche's book is up-to-date with the latest in astronomy. It contains accurate astronomical data on stars and constellations. The topics are incorporated with web site addresses for the reader to expand his/her knowledge and see high-resolution images of the celestial targets. This edition incorporates new discoveries and suggestions made prior to the first editions. Among the new developments is the twenty-first-century research into black holes, active galaxies and quasars, searches for life in space, origin and structure of our universe, and the latest in ground and space telescopes.