An empirical method for improving the quality of RXTE PCA spectra
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- MIT Kavli Institute for Astrophysics and Space Research, MIT, 70 Vassar Street, Cambridge, MA 02139 (United States)
We fitted all of the several hundred RXTE PCA spectra of the Crab individually to a simple power-law model; the total number of counts in the composite spectrum is >10{sup 9}. We then used the spectrum of residuals to derive a calibration tool, called pcacorr, that we apply to large samples of spectra for GX 339-4, H1743-322, and XTE J1550-564. Application of the tool improved the quality of all the fits, and the improvement is dramatic for spectra with ≳ 10{sup 7} counts. The Crab residual spectrum is somewhat different for each of the five Proportional Counter Array (PCA) detectors, but it was relatively stable over the course of the mission. We recommend that pcacorr be routinely applied to spectra with ≳ 10{sup 6} counts and that one include a systematic error of 0.1%, rather than the 0.5-1% value that has customarily been used. We expect that application of the tool will result in an increase in sensitivity of the PCA to faint spectral features by up to an order of magnitude.
- OSTI ID:
- 22370471
- Journal Information:
- Astrophysical Journal, Vol. 794, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
MEASURING BLACK HOLE SPIN VIA THE X-RAY CONTINUUM-FITTING METHOD: BEYOND THE THERMAL DOMINANT STATE
TEMPORAL VARIABILITY FROM THE TWO-COMPONENT ADVECTIVE FLOW SOLUTION AND ITS OBSERVATIONAL EVIDENCE