5,056 research outputs found

    On the Optical Search for Centaurus X-3

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    The optical eclipsing binary LR Cen has been eliminated as a candidate for Cen X-3 on the basis of a real discrepancy of orbital periods. We believe that the position coincidence of Wray 795 with Cen X-3 is not statistically significant

    The 8-14-μ Appearance of Venus Before the 1964 Conjunction

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    In an earlier paper (Murray, Wildey, and Westphal 1963) we have described the detailed mapping of the 8-14-μ radiation from Venus using the 200-inch Hale telescope. This paper extends that work over a period of about 7 months from December 15, 1963, to June 6, 1964. Detailed maps for 6 days are presented that show the morphology of the upper-atmosphere brightness temperature and illustrate a number of anomalous features near the cusps. The problem of atmospheric extinction and the derived brightness temperature is discussed

    A Phase Transition between Small and Large Field Models of Inflation

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    We show that models of inflection point inflation exhibit a phase transition from a region in parameter space where they are of large field type to a region where they are of small field type. The phase transition is between a universal behavior, with respect to the initial condition, at the large field region and non-universal behavior at the small field region. The order parameter is the number of e-foldings. We find integer critical exponents at the transition between the two phases.Comment: 21 pages, 8 figure

    New Candidate Interstellar Particle in Stardust IS Aerogel Collector: Analysis by STXM and Ptychography

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    The Stardust Interstellar Preliminary Examination (ISPE) reported in 2014 the discovery of 7 probable contemporary interstellar (IS) particles captured in Stardust IS Collector aerogel and foils. The ISPE reports represented work done over 6 years by more than 60 scientists and >30,000 volunteers, which emphasizes the challenge identifying and analyzing Stardust IS samples was far beyond the primary Stardust cometary collection. We present a new potentially interstellar particle resulting from a continuation of analyses of the IS aerogel collection

    Sco X-1: The Evolution and Nature of the Twin Compact Radio Lobes

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    The radio components associated with the LMXB Sco X-1 have been monitored with extensive VLBI imaging at 1.7 and 5.0 GHz over four years, including a 56-hour continuous VLBI observation in 1999 June. We often detected one strong and one weak compact radio component, moving in opposite directions from the radio core. We suggest that the moving components are radio lobes generated by the disruption of energy flow in a twin-beam from the binary system. The average lifetime of a lobe-pair, the space motion of the lobes and the measured energy flow in the beam are discussed in arXiv:astro-ph/0104325. The lobe has a flux density that is variable over a time-scale of one hour, a measured minimum size of 1 mas (2.8 au), and is extended perpendicular to its motion. This short electron radiative lifetime may be caused by synchrotron losses if the lobe magnetic field is 300 G, or by adiabatic expansion of the electrons as soon as they are produced at the working surface. The lobes also show periods of slow expansion and a steepening radio spectrum, perhaps related to the characteristics of the beam energy flow. The radio morphology for Sco X-1 is more simple than for most other Galactic jet sources. The lobes of Sco X-1 are similar to hot-spots found in many extragalactic double sources. Scaling the phenomena observed in Sco X-1 to extragalactic sources implies hot-spot variability time-scales of 10^4 yr and hot-spot lifetimes of 10^5 yr. The recurrent formation of lobes in Sco X-1 probably does not occur for extragalactic radio sources.Comment: 22 pages of text + 16 figures. ApJ, in pres
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