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  1. No Access

    Article

    Submillisecond optical pulsar in supernova 1987A

    WE have detected an optical pulsar with frequency f = 1,968.629 Hz at the location of supernova 1987A in the Large Magellanic Cloud. The brightness of the pulsed light increased from magnitude 19 to 18 during a 7...

    J. Kristian, C. R. Pennypacker, J. Middledrtch, M. A. Hamuy, J. N. Imamura… in Nature (1989)

  2. No Access

    Chapter and Conference Paper

    BL Lacertae objects detected in the HEAO-1 all sky X-ray survey

    We discuss 20 X-ray sources in the NRL HEAO-1 catalog which we identify with bright, hard X-ray emitting BL Lac objects. We discuss the definition and process of identification of these objects. We deduce limi...

    D. A. Schwartz, R. J. V. Brissenden, I. R. Tuohy, E. D. Feigelson… in BL Lac Objects (1989)

  3. No Access

    Chapter

    Quasars Contributing to the Extragalactic X-Ray Flux: The Deep X-Ray Survey in Pavo

    The nature of discrete x-ray sources contributing to the all-sky x-ray background has been investigated. X-ray selected quasars account directly for ~ 30% of the all-sky x- ray background in the energy range o...

    R. E. Griffiths, I. R. Tuohy, R. J. V. Brissenden… in The Post-Recombination Universe (1988)

  4. No Access

    Article

    Zeeman features from accretion columns in AM Herculis-type systems

    Absorption features seen in the bright phase spectra of E1405-451 are identified with Zeeman features of Hα originating from cool (T∼104–105°K) material surrounding the accretion shock. The presence of apparently...

    D. T. Wickramasinghe, I. R. Tuohy, N. Visvanathan in Astrophysics and Space Science (1987)

  5. No Access

    Chapter and Conference Paper

    Zeeman Features from Accretion Columns in AM Herculis-Type Systems

    Absorption features seen in the bright phase spectra of E1405-451 are identified with Zeeman features of Hα originating from cool (T~104-105 °K) material surrounding the accretion shock. The presence of apparentl...

    D. T. Wickramasinghe, I. R. Tuohy… in Cataclysmic Variables. Recent Multi-Freque… (1987)

  6. No Access

    Article

    Photometry, polarimetry, and spectroscopy of AM Herculis variables

    We report AAT observations of two southern AM Herculis variables, H0139-68 and E1405-451. H0139-68 was found to be in an unusually faint state (V≳17), and this has permitted the first measurement of the magnetic ...

    I. R. Tuohy, N. Visvanathan, D. T. Wickramasinghe in Astrophysics and Space Science (1986)

  7. No Access

    Chapter

    Photometry, Polarimetry, and Spectroscopy of am Herculis Variables

    We report AAT observations of two southern AM Herculis variables, H0139-68 and E1405–451. H0139–68 was found to be in an unusually faint state (V≳17), and this has permitted the first measurement of the magnetic ...

    I. R. Tuohy, N. Visvanathan… in Third Asian-Pacific Regional Meeting of th… (1986)

  8. No Access

    Chapter

    The Peculiar X-Ray Morphology of the SNR G292.0+1.8 : Evidence for an Asymmetric Supernova Explosion

    A high resolution X-ray image from the Einstein Observatory of the young supernova remnant G292.0+1.8 (MSHll-54), previously noted as peculiar in terms of its spectral and morphological properties at optical and ...

    D. H. Clark, I. R. Tuohy in Supernova Remnants and their X-Ray Emission (1983)

  9. No Access

    Chapter

    A Search for Pulsars Associated with Supernova Remnants in the Galaxy and the Magellanic Clouds

    It is widely accepted and almost certainly true that both pulsars and supernova remnants (SNRs) are products of the collapse of a star at the end of its evolution. Given this, it is a considerable puzzle why, ...

    R. N. Manchester, I. R. Tuohy, N. D’Amico in Supernova Remnants and their X-Ray Emission (1983)

  10. No Access

    Chapter

    Optical Studies of Supernova Remnants in the Magellanic Clouds

    Optical identifications of 32 X-ray sources in the Magellanic Clouds confirm that they are SNRs. They are separated into four classes: the evolved, the oxygen-rich, the Balmer-dominated and the Crab-like. High...

    D. S. Mathewson, V. L. Ford, M. A. Dopita… in Supernova Remnants and their X-Ray Emission (1983)

  11. No Access

    Chapter

    Optical Observations of Four Balmer-Dominated Supernova Remnants in the Large Magellanic Cloud

    We report the optical identification of four Balmer-dominated supernova remnants (SNRs) in the Large Magellanic Cloud. Both the Balmer-dominated spectra and the presence of a broad Ha component in one remnant ...

    I. R. Tuohy, M. A. Dopita, D. S. Mathewson… in Supernova Remnants and their X-Ray Emission (1983)

  12. No Access

    Article

    Microwave emission from flare star AT Mic

    There have been several comprehensive optical and low-frequency radio surveys of flare stars1,2 but much less attention has been directed to the microwave emission from such stars. Slee and Page3 claimed to have ...

    O. B. Slee, I. R. Tuohy, G. J. Nelson, C. J. Rennie in Nature (1981)