NAME

ratefit -- Fits PSPC observation light curves in seven broad pulse-height bands.


USAGE

ratefit bndcntrl i0val i0flag ... i4val i4flag is0val isoflag is1val is1flag


DESCRIPTION

Ratefit fits the PSPC observation light curves produced by rate in seven broad pulse-height bands. The light curves are assumed to consist of a flat cosmic component, the calibrated particle background component, a linear scaling of the scattered solar X-ray component computed by the program AO, and a polynomial (up to fourth-order) describing the long-term enhancement background component. The constant cosmic background component is fit as part of the polynomial. The linear scale factor for the scattered solar X-rays (first-order polynomial coefficients) and the fourth-order polynomial coefficients of the long-term enhancement plus cosmic background components are fit by the program.



The RATEFIT package uses the following input files.

1) Observation data fits files : none

2) Other fixed input : valid_times_all.dat from the program VALID_TIMES, RATE1.DAT and RATE2.DAT from the program RATE, AO_SSX_SC.OUT from the program AO.

Interactive Input: 1) Band control: input 1-7 for pulse-height bands R1-R7. For this program, selecting 1 will serve for either band R1 or band R1L, as selected by the gain control of the program RATE (i.e., for the gain parameter 1 band R1 is produced, for the gain parameter 2 or 3, band R1L is produced). 2) Guess for the constant coefficient of the fourth-order polynomial - if the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero. 3-6) Guesses for the remaining coefficients of the polynomial - see 2) above. 7) Guess for the constant coefficient of the first-order polynomial for the scattered solar X-ray background - see 2) above. 8) Guess for the linear coefficient of the first-order polynomial for the scattered solar X-ray background - see 2) above.

Screen Output: The program lists time offset (T0) and the values for the fitted parameters (I0 - I4 for the fourth-order polynomial and IS0 and IS1 for the linear scale factor) along with the formal uncertainties and chi square statistics. Note that a statistically-significant chi-square is not necessary. The goal is to get a reasonable fit to the general variation of the light curve, not to model the detailed variations (e.g., see the description for RATE). The values I0 - I4 will be used in the program LTE while the values IS0 and IS1 will be used in the program TILT. T0 will be used in both.

Ascii Output: 1) A QDP plot file is written with the name plot_n.qdp where n refers to the band which was fit. This plot should be examined to verify the quality of the fit and to identify possible short-term background enhancements that should be excluded. The specific times of background enhancements can be identified by using the RATE1.DAT and RATE2.DAT, which have the S/C time and count rates in the individual bands.

PARAMETERS

(bndcntrl = "") [integer]
Band Control Parameter; input 1-7 for pulse-height bands R1-R7.

(i0val = "1.0") [real]
Guess for the constant coefficient of the fourth-order polynomial.

(i0flag = "0") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.

(i1val = "1.0") [real]
Guess for the first-order coefficient of the fourth-order polynomial.

(i1flag = "0") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.

(i2val = "0.1") [real]
Guess for the second-order coefficient of the fourth-order polynomial.

(i2flag = "0") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.

(i3val = "0.0") [real]
Guess for the third-order coefficient of the fourth-order polynomial.

(i3flag = "1") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.

(i4val = "0.0") [real]
Guess for the fourth-order coefficient of the fourth-order polynomial.

(i4flag = "1") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.

(is0val = "1.0") [real]
The value for SSX scale IS0. Guess for the constant coefficient of the first-order polynomial for the scattered solar X-ray background.

(is0flag = "0") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.

(is1val = "0.0") [real]
The value for SSX scale IS1. Guess for the linear coefficient of the first-order polynomial for the scattered solar X-ray background.

(is1flag = "1") [integer]
If the guess is non-zero, the program will query whether the coefficient should be fixed (enter 1) or not (enter 0). If the guess is zero, the program fixes the parameter at zero.


EXAMPLES

1. For RL1 band assuming default values;


ft> ratefit 1 1.0 0 1.0 0 0.1 0 0.0 1 0.0 1 1.0 0 0.0 1


BUGS


CATEGORY

Dec96 ftools.rosat