Note: Gr#13 has been repaired, Grisms #9, #12, and #15
have been replaced
by Gr#18, Gr#16, and Gr#17 respectively. Gr#10 suffered a
major damage and is no longer offered. (14/06/2007)
In case of
questions, please contact
lsefosc@eso.org.
Grisms are mounted on the grism wheel in the parallel beam of EFOSC2 and so they do not introduce any wavelength dependent optical aberrations in the spectra.
Grisms  Range  Grating  Blaze angle  Dispersion ^{1}  Resolution ^{2}  Plots (PS Gzipped^{6}  Tables^{6}  Comments  

Name  [Å]  gr/mm  wavelengh [Å]  [Å/pixel]  FWHM [Å] *  Efficiency 

Throughput [Å]  








^{3} >9280Å  







ps  ^{3} >9850Å  






































^{3} >6280Å 








html  ^{4} 


















replaced by Gr#18  









Gr#10 decommisioned 


















replaced by Gr#16  


















^{4}  







replaced by Gr#17  








^{3} >7170Å  







^{3} >7000Å  

















^{5}  


1070 





^{3} >6900Å ^{5} 
^{1}The pixel mentioned in the dispersion
column is the 0.12
arcsec unbinned pixel of CCD #40.
^{2}The resolution depends on the slit used. Those
quoted here
are for a 1.0" slit.
^{3}2nd order contamination has been found for
these grims
at wavelengths longer than the indicated one.
^{4}Grisms 7 and 14 are almost identical;
see the manual (section 2.4.5) for a comparison.
^{5}Grism
Dispersion and Resolution measured using a 0.5" slit and 1x1 binning.
In an independent test Vik Dhillon found Grism dispersions of 0.
287 Å/pixel and 0.480 Å/pixel for Gr#19 and
Gr#20, respectively. The corresponding resolutions are: 1.08 Å
(Gr#19) and 1.77 Å (Gr#20). This test was performed
using a 0.5" slit.
All the efficiency and response funcion reported below are still for EFOSC2 @ 3P6
Efficiency
curves for
all grisms, 2004 (JPG 55 kb).
Response
curves for
all grisms, 2003 (PDF 36 kb).
Response
curves for
all grisms, 1999 (PS 162 kb).