HZ 21 Effective Area Calculation
Derived from PAT_A and PAT_B observations
- SIMBAD entry
- Coords: 183.48445834,32.94205556
- U MAG(Vega): 13.1
- NUV MAG(AB): 13.125
- FUV MAG(AB): 12.545
Processed with new spectral flats (newcfg cmdev) on 14-Jan-2008
For the latest Effective Area Curve calculation and for more details click here.
Data Set: Each of the PAT_A and PAT_B tiles had three
visits divided into six subvisits using the particular pattern for a total
of 36 individual observations that are analyzed for this EA curve:
2 x 6 x 3 = 36. The relevant data are all copied to a
directory called hz21/ea_cal/.
Procedure: The *-ng-xsp.fits and *-fg-xsp.fits files
are read in and the counts and errors are dispersion corrected to 1 Ang/px
with the IDL routine gx_dc_cnts.pro, which uses the standard
wavelength polynomials. These observations are compared individually with
STIS calibration spectra with the same wavelength scale to derive an
effective area curve. At each wavelength an error-weighted mean effective
area is calculated. This was then smoothed with a boxcar size of 25
Angstroms (pixels). The calling routine that does the averaging is
gx_ea_cal.pro. Click on the <EA> below to retrieve the
resulting EA table.
Plots: The top plot shows the average EA curve as the thin lines and the smoothed curves as the thick lines. The standard deviation is indicated by the red lines and the error in the mean is shown by the green lines. The bottom plot shows the ratio of each individual curve to the average curve. Click on image to retrieve postscript of plot.
| <EA> |  |
| EA/<EA> |  |