4,630 research outputs found

    Extended Emission from Cygnus X-3 Detected with Chandra

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    We have discovered extended X-ray emission from the microquasar Cyg X-3 in archival Chandra X-ray Observatory observations. A 5" wide structure lies approximately 16" to the NE from the core point source and may be extended in that direction. This angular scale corresponds to a physical extent of roughly 0.8 lyr, at a distance of 2.5 lyr from Cyg X-3 (assuming a 10 kpc distance). The flux varied by a factor of 2.5 during the four months separating two of the observations, indicating significant substructure. The peak 2-10 keV luminosity was about 5e34 ergs/s. There may also be weaker, extended emission of similar scale oppositely directed from the core, suggesting a bipolar outflow. This structure is not part of the dust scattering halo, nor is it caused by the Chandra point spread function. In this Letter we describe the observations and discuss possible origins of the extension.Comment: Submitted to ApJ Letters. 5 pages, 2 figures (1 color). Uses emulateap

    RXTE Observations of LMC X-1 and LMC X-3

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    Of all known persistent stellar-mass black hole candidates, only LMC X-1 and LMC X-3 consistently show spectra that are dominated by a soft, thermal component. We present results from long (170ksec) Rossi X-ray Timing Explorer (RXTE) observations of LMC X-1 and LMC X-3 made in 1996 December. The spectra can be described by a multicolor disk blackbody plus an additional high-energy power-law. Even though the spectra are very soft (Gamma is about 2.5), RXTE detected a significant signal from LMC X-3 up to energies of 50keV, the hardest energy at which the object was ever detected. Focusing on LMC X-3, we present results from the first year of an ongoing monitoring campaign with RXTE which started in 1997 January. We show that the appearance of the object changes considerably over its ~200d long cycle. This variability can either be explained by periodic changes in the mass transfer rate or by a precessing accretion disk analogous to Her X-1.Comment: 4 pages, 5 figures, also available at http://aitzu3.ait.physik.uni-tuebingen.de/publications/preprints1998.html to be published in "Highlights of X-Ray Astronomy, a symposium in honour of Joachim Truemper" (B. Aschenbach et al., eds.), MPE Repor

    Monitoring the Short-Term Variability of Cyg X-1: Spectra and Timing

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    We present first results from the spectral and temporal analysis of an RXTE monitoring campaign of the black hole candidate Cygnus X-1 in 1999. The timing properties of this hard state black hole show considerable variability, even though the state does not change. This has previously been noted for the power spectral density, but is probably even more pronounced for the time lags. From an analysis of four monitoring observations of Cyg X-1, separated by 2 weeks from each other, we find that a shortening of the time lags is associated with a hardening of the X-ray spectrum, as well as with a longer characteristic ``shot time scale''. We briefly discuss possible physical/geometrical reasons for this variability of the hard state properties.Comment: 5 pages, 2 figures, Proc. of the 5th Compton Symposium, AIP, in pres

    "Det var jag som var den dÀr vuxna och han var ett barn" : En kvalitativ studie om hur det Àr att vara ett vuxet barn till en alkoholist

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    Syftet med vĂ„rt lĂ€rdomsprov Ă€r att undersöka hur uppvĂ€xten i en alkoholistfamilj har pĂ„verkat det vuxna barnet. Vi undersöker Ă€ven vilka konsekvenser det vuxna barnet fĂ„tt av uppvĂ€xten, vilket förhĂ„llningssĂ€tt det vuxna barnet har till alkohol och hur relationen mellan det vuxna barnet och den missbrukande förĂ€ldern ser ut. I teoridelen definieras alkoholismen; vad Ă€r alkoholism, vem kan bli alkoholist och vad Ă€r skillnaden mellan en alkoholist och en storkonsument. Vidare faststĂ€lls missbrukets effekt pĂ„ familjen, samt barnens roller i en alkoholistfamilj. Även typiska karaktĂ€rsdrag och konsekvenser i vuxenlivet tas upp. I undersökningen har vi anvĂ€nt oss av kvalitativ undersökning. Vi har intervjuat fyra personer som har en pappa som Ă€r alkoholist. I resultatet framkommer bĂ„de likheter och olikheter mellan vuxna barn till alkoholister, men den gemensamma nĂ€mnaren Ă€r konsekvenser i vuxenlivet för alla barn som levt med en alkoholiserad förĂ€lder.The aim of our thesis is to investigate how growing up with an alcoholic parent has affected the adult child. We also examine the impact on the adult child as a result of growing up in a family where one parent is or was an alcoholic, what kind of attitude the adult child has to alcohol and how the relationship between the adult child and the alcoholic parent has been affected. In our theoretical part, we define alcoholism; what is alcoholism, who can become an alcoholic and what is the difference between an alcoholic and a big consumer. Further down we establish the impact on the family and the children's roles in the family. We also cover the typical characteristics and consequences in adult life. In the survey, we used a qualitative research. We have interviewed four people who have a father who is an alcoholic. The result shows both similarities and differences between adult children of alcoholics, but the common denominator is that all children of alcoholics are affected in adulthood