An Empirical Method for Improving the Quality of RXTE PCA Spectra

Abstract

We fitted all of the several hundred {\it RXTE} PCA spectra of the Crab individually to a simple power-law model; the total number of counts in the composite spectrum is $>10^9$. We then used the spectrum of residuals to derive a calibration tool, called {\tt 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 $\gtrsim 10^7$ counts. The Crab residual spectrum is somewhat different for each of the five PCA detectors, but it was relatively stable over the course of the mission. We recommend that {\tt pcacorr} be routinely applied to spectra with $\gtrsim 10^6$ 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.

11 pages, 16 figures. Accepted in ApJ

References in corpus (2)

• X-ray Properties of Black-Hole Binaries
• When A Standard Candle Flickers

Cited by in corpus (16)

• A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass
• Re-estimating the Spin Parameter of the Black Hole in Cygnus X-1
• Reflection Modeling of the Black Hole Binary 4U~1630$-$47: the Disk Density and Returning Radiation
• Stronger Reflection from Black Hole Accretion Disks in Soft X-ray States
• Long term variability of Cygnus X-1. VIII. A spectral-timing look at low energies with NICER
• Combining timing characteristics with physical broadband spectral modelling of black hole X-ray binary GX~339$-$4
• The impact of neutron star spin on X-ray spectra
• The giant outburst of 4U 0115+634 in 2011 with Suzaku and RXTE
• Measuring Black Hole Spins through X-ray Reflection Spectroscopy and the Relativistic Precession Model: the case of XTE J1859+226
• Pulsating iron spectral features in the emission of X-ray pulsar V0332+53
• The long-stable hard state of XTE J1752-223 and the disk truncation dilemma
• Proof of principle X-ray reflection mass measurement of the black hole in H1743-322
• Accretion Disc Evolution in GRO J1655-40 and LMC X-3 with Relativistic and Non-Relativistic Disc Models
• Estimating the spin of the black hole candidate MAXI J1659-152 with the X-ray continuum-fitting method
• Phase Evolution of the Crab Pulsar between Radio and X-ray
• Testing Relativistic Accretion Disk Models with GRO J1655-40