19 research outputs found

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

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    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

    Systematics of the Pacific monkey-faced bats (Chiroptera : Pteropodidae), with a new species of Pteraloplex and a new Fijian genus

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    Copyright © 2005 The Natural History MuseumThe fruit-bat genus Pteralopex comprises the monkey-faced bats, a group of six endangered species found only in old-growth forests on certain islands in the south-west Pacific (the Solomon Islands and Fiji). The taxonomy of the genus is reviewed in detail and updated accordingly. Two ‘cryptic’ biological species are shown to occur in sympatry on both Bougainville and Choiseul in the northern Solomon Islands (corresponding to Pteralopex anceps Andersen, 1909 and a previously undescribed species) and each is accordingly described and reviewed. A new genus (Mirimiri) is erected for the Fijian monkey-faced bat (formerly Pteralopex acrodonta), which differs greatly both morphologically and genetically from species of Pteralopex in the Solomon Islands. Ecomorphological differences between sympatric Pteralopex species are briefly reviewed, including potential differences in functional morphology and feeding ecology. Geographic patterns of occurrence and future survey priorities for monkey-faced bats are also discussed.Kristofer M. Helge
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