D.A. Swartz

Publications (3)2.46 Total impact

• Article: The demographics of ultraluminous X‐ray sources

  D.A. Swartz
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  ABSTRACT: Results of recent statistical studies of the population of ultraluminous X-ray sources are presented. Special emphasis is placed on the outcome of a complete survey of 140 nearby galaxies hosting 114 ULXs. It is shown that ULXs are preferentially associated with young star-forming regions but not necessarily with massive young clusters, that ULXs occur at a higher rate (per unit mass) in dwarf galaxies compared to giant galaxies and that ULXs rarely occur in galactic halos. If an upper limit to the luminosity of ULXs exists, then it must be above several times 1040 erg s–1 in the X-ray band. The luminosity function is still too sparsely sampled above this luminosity for a more definitive statement to be made (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
  Astronomische Nachrichten 04/2011; 332(4):341 - 344. · 1.01 Impact Factor
• Article: Simulation study of COSMIC-a Compton telescope all-sky monitor concept for low-energy gamma-ray astronomy

  R.M. Kippen, W.S. Paciesas, G.N. Pendleton, D.A. Swartz
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  ABSTRACT: The highly transient nature of cosmic low-energy gamma-ray sources offers unique insight into the astrophysics of extreme processes. Sensitive, long-term, all-sky monitoring is required to make sense of the variable emission. Instrumentation for such observations must have the combination of large effective collection area, wide field-of-view and good angular resolution. Recent advances in position-sensitive detectors and associated electronics make it possible to consider a multi-scatter Compton telescope, combined with a coded mask, as an all-sky monitor in the energy range ~10 keV to a few MeV. We present simulations of various configurations of such an instrument and show that it can provide a substantial improvement over other sky monitor strategies in this energy regime
  IEEE Transactions on Nuclear Science 01/2001; · 1.45 Impact Factor
• Conference Proceeding: COSMIC: a Compton telescope all-sky monitor for low-energygamma-ray astronomy

  R. M. Kippen, W. S. Paciesas, G. N. Pendleton, D.A. Swartz
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  ABSTRACT: The highly transient nature of cosmic low-energy gamma-ray sources offers unique insight into the astrophysics of extreme processes. Sensitive, long-term, all-sky monitoring is required to make sense of the variable emission. Instrumentation for such observations must have the combination of large effective collection area, wide field-of-view and good angular resolution. Recent advances in position-sensitive detectors and associated electronics make it possible to consider a multi-scatter Compton telescope, combined with a coded mask, as an all-sky monitor in the energy range ~10 keV to a few MeV. We present simulations of various configurations of such an instrument and show that it can provide a substantial improvement over other sky monitor strategies in this energy regime
  Nuclear Science Symposium, 1998. Conference Record. 1998 IEEE; 02/1998