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Hubble Space Telescope
System Throughputs

This page presents throughput curves in graphic and tabular form. These data have been generated with Pysynphot and are the transmission at launch in March 2002. The total throughputs represent the fractional photon detection efficiency in terms of photons in vs. detected photo-electrons. The variation with time is documented by Bohlin, Mack, and Ubeda (2011, hereafter ISR-III). This time variability is incorporated in the Quantum Efficiency (QE) ACS instrument component file; and the amount of change with time is summarized by the changes in the flux calibration keyword PHOTFLAM in Table 7 of Bohlin (2012, hereafter ISR-IV). For example, the maximum change for WFC over its initial operational period from 2002.16 to 2007.1 at the loss rate of 0.26/year is 1.3% for six filters in Table 1 of ISR-III. After SM4 in 2009 May, the sensitivity drops by at most another 0.7% for a total loss of 2.0% in F550M. This change is reflected in the PHOTFLAM change from 3.906e-19 to 3.984e-19 in Table 7 of ISR-IV. Also, see the ACS Zeropoints web page.

If desired, more accurate throughput curves for a particular time may be acquired by using Pysynphot in the following way:

# The first line applies within STScI only.
# set this environment variable to the root directory where you have installed
# Pysynphot's reference files.

setenv PYSYN_CDBS /grp/hst/cdbs/
python
>>> import pysynphot as S

# Generate a bandpass for an observational setup and time (in MJD).

>>> bp = S.ObsBandpass ('acs,wfc1,f606w,mjd#52340')

# Now, bp.wave and bp.throughput are the wavelength and transmission
# arrays, respectively.

Please consult the Pysynphot Documentation for more details.

ACS Throughput Tables


The total throughput curve (HST+ACS) can be downloaded by clicking on a filter name.
WFCHRCSBC
F435WF220WF115LP
F475WF250WF125LP
F502NF330WF140LP
F550MF344NF150LP
F555WF435WF165LP
F606WF475WF122M
F625WF502NPR110L
F658NF550MPR130L
F660NF555W
F775WF606W
F814WF625W
F850LPF658N
F892NF660N
F775W
F814W
F850LP
F892N

Plots

REFERENCES

Last modified on May 15, 2012.