2,456 research outputs found
New BeppoSAX-WFC results on superbursts
Presently seven superbursters have been identified representing 10% of the
total Galactic X-ray burster population. Four superbursters were discovered
with the Wide Field Cameras (WFCs) on BeppoSAX and three with the All-Sky
Monitor and Proportional Counter Array on RXTE. We discuss the properties of
superbursters as derived from WFC observations. There are two interesting
conclusions. First, the average recurrence time of superbursts among X-ray
bursters that are more luminous than 10% of the Eddington limit is 1.5 yr per
object. Second, superbursters systematically have higher alpha values and
shorter ordinary bursts than most bursters that have not exhibited superbursts,
indicating a higher level of stable thermonuclear helium burning. Theory
predicts hitherto undetected superbursts from the most luminous neutron stars.
We investigate the prospects for finding these in GX~17+2.Comment: Submitted in January 2004 for the Proceedings of the meeting 'X-Ray
Timing 2003: Rossi and Beyond', eds. P. Kaaret, F. K. Lamb, & J. H. Swank
(Melville, NY: American Institute of Physics
Bright X-ray bursts from 1E 1724-3045 in Terzan 2
During about 3 years wide field monitoring of the Galactic Center region by
the WFC telescopes on board the BeppoSAX satellite, a total of 14 type-I X-ray
bursts were detected from the burster 1E 1724-3045 located in the globular
cluster Terzan 2. All the observed events showed evidence for photospheric
radius expansion due to Eddington-limit burst luminosity, thus leading to an
estimate of the source distance (~7.2 kpc). Preliminary results of the analysis
of the bursts are presented.Comment: 5 pages, 2 figures, Proc. 5th Compton Symp., Portsmouth 199
Does Docket Size Matter? Revisiting Empirical Accounts of the Supreme Court\u27s Incredibly Shrinking Docket
Drawing on data from every Supreme Court Term between 1940 and 2017, this Article revisits, updates, and expands prior empirical work by Ryan Owens and David Simon (2012) finding that ideological, contextual, and institutional factors contributed to the Court’s declining docket. This Article advances Owens and Simon’s work in three ways: broadening the scope of the study by including nine additional Court Terms (through 2017), adding alternative ideological and nonideological variables into the model, and considering alternative model specifications. What emerges from this update and expansion, however, is less clarity and more granularity and complexity. While Owens and Simon emphasized the salience of ideological distance across Justices as well as ideological distance separating the Supreme Court from the lower federal appellate courts, results from our study, by contrast, suggest that when it comes to ideological differences, intra-Court rather than intercourt ideological distance emerged, on balance, as critical. Other variables also emerged as persistently important, notably Congress’s decision in 1988 to remove much of the Court’s mandatory appellate jurisdiction and variation in the total number of certiorari petitions filed. Finally, these core findings appear robust across alternative model specifications. While most commentators react to a diminishing Court docket by emphasizing possible adverse consequences, rather than commit to any normative position, our Article instead considers both the possible institutional costs and benefits incident to a declining Court docket, with an emphasis on structural horizontal separation of powers implications
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