diff --git a/src/ctbkgcube/ctbkgcube.par b/src/ctbkgcube/ctbkgcube.par
index a4b496f..da61602 100644
--- a/src/ctbkgcube/ctbkgcube.par
+++ b/src/ctbkgcube/ctbkgcube.par
@@ -21,7 +21,7 @@ inobs,    f, a, "NONE",,, "Input event list or observation definition XML file"
 inmodel,  f, a, "NONE",,, "Input model XML file"
 incube,   f, a, "NONE",,, "Input counts cube file to extract background cube definition"
 caldb,    s, a, "prod2",,, "Calibration database"
-irf,      s, a, "South_50h",,, "Instrument response function"
+irf,      s, a, "South_0.5h",,, "Instrument response function"
 outcube,  f, a, "bkgcube.fits",,, "Output background cube file"
 outmodel, f, a, "NONE",,, "Output model XML file"
 
diff --git a/src/ctbutterfly/ctbutterfly.par b/src/ctbutterfly/ctbutterfly.par
index 971856d..3e20ea9 100644
--- a/src/ctbutterfly/ctbutterfly.par
+++ b/src/ctbutterfly/ctbutterfly.par
@@ -24,7 +24,7 @@ expcube,    f, a, "NONE",,, "Input exposure cube file (only needed for stacked a
 psfcube,    f, a, "NONE",,, "Input PSF cube file (only needed for stacked analysis)"
 bkgcube,    f, a, "NONE",,, "Input background cube file (only needed for stacked analysis)"
 caldb,      s, a, "prod2",,, "Calibration database"
-irf,        s, a, "South_50h",,, "Instrument response function"
+irf,        s, a, "South_0.5h",,, "Instrument response function"
 edisp,      b, h, no,,, "Apply energy dispersion?"
 outfile,    f, a, "butterfly.txt",,, "Output ASCII file"
 
diff --git a/src/cterror/cterror.par b/src/cterror/cterror.par
index 91a4a03..9e7f3c8 100644
--- a/src/cterror/cterror.par
+++ b/src/cterror/cterror.par
@@ -25,7 +25,7 @@ expcube,  f, a, "NONE",,, "Input exposure cube file (only needed for stacked ana
 psfcube,  f, a, "NONE",,, "Input PSF cube file (only needed for stacked analysis)"
 bkgcube,  f, a, "NONE",,, "Input background cube file (only needed for stacked analysis)"
 caldb,    s, a, "prod2",,, "Calibration database"
-irf,      s, a, "South_50h",,, "Instrument response function"
+irf,      s, a, "South_0.5h",,, "Instrument response function"
 edisp,    b, h, no,,, "Apply energy dispersion?"
 outmodel, f, a, "results.xml",,, "Output model XML file"
 
diff --git a/src/ctexpcube/ctexpcube.par b/src/ctexpcube/ctexpcube.par
index 008ddf6..f0ea8bf 100644
--- a/src/ctexpcube/ctexpcube.par
+++ b/src/ctexpcube/ctexpcube.par
@@ -20,7 +20,7 @@
 inobs,    f, a, "NONE",,, "Input event list or observation definition XML file"
 incube,   f, a, "NONE",,, "Input counts cube file to extract exposure cube definition"
 caldb,    s, a, "prod2",,, "Calibration database"
-irf,      s, a, "South_50h",,, "Instrument response function"
+irf,      s, a, "South_0.5h",,, "Instrument response function"
 edisp,    b, h, no,,, "Apply energy dispersion?"
 outcube,  f, a, "expcube.fits",,, "Output exposure cube file"
 
diff --git a/src/ctlike/ctlike.par b/src/ctlike/ctlike.par
index b9668e8..b352d9a 100644
--- a/src/ctlike/ctlike.par
+++ b/src/ctlike/ctlike.par
@@ -23,7 +23,7 @@ expcube,         f, a, "NONE",,, "Input exposure cube file (only needed for stac
 psfcube,         f, a, "NONE",,, "Input PSF cube file (only needed for stacked analysis)"
 bkgcube,         f, a, "NONE",,, "Input background cube file (only needed for stacked analysis)"
 caldb,           s, a, "prod2",,, "Calibration database"
-irf,             s, a, "South_50h",,, "Instrument response function"
+irf,             s, a, "South_0.5h",,, "Instrument response function"
 edisp,           b, h, no,,, "Apply energy dispersion?"
 outmodel,        f, a, "crab_results.xml",,, "Output model XML file"
 
diff --git a/src/ctmodel/ctmodel.par b/src/ctmodel/ctmodel.par
index eb96c5b..8534e95 100644
--- a/src/ctmodel/ctmodel.par
+++ b/src/ctmodel/ctmodel.par
@@ -24,7 +24,7 @@ expcube,  f, a, "NONE",,, "Input exposure cube file (only needed for stacked ana
 psfcube,  f, a, "NONE",,, "Input PSF cube file (only needed for stacked analysis)"
 bkgcube,  f, a, "NONE",,, "Input background cube file (only needed for stacked analysis)"
 caldb,    s, a, "prod2",,, "Calibration database"
-irf,      s, a, "South_50h",,, "Instrument response function"
+irf,      s, a, "South_0.5h",,, "Instrument response function"
 edisp,    b, h, no,,, "Apply energy dispersion?"
 outcube,  f, a, "modcube.fits",,, "Output model cube file"
 
diff --git a/src/ctobssim/ctobssim.par b/src/ctobssim/ctobssim.par
index 135ad47..deee287 100644
--- a/src/ctobssim/ctobssim.par
+++ b/src/ctobssim/ctobssim.par
@@ -20,7 +20,7 @@
 inobs,     f, h, "NONE",,, "Input event list or observation definition XML file"
 inmodel,   f, a, "$CTOOLS/share/models/crab.xml",,, "Input model XML file"
 caldb,     s, a, "prod2",,, "Calibration database"
-irf,       s, a, "South_50h",,, "Instrument response function"
+irf,       s, a, "South_0.5h",,, "Instrument response function"
 edisp,     b, h, no,,, "Apply energy dispersion?"
 outevents, f, a, "events.fits",,, "Output event data file or observation definition XML file"
 prefix,    s, h, "sim_events_",,, "Prefix for event lists in observation definition XML file"
diff --git a/src/ctpsfcube/ctpsfcube.par b/src/ctpsfcube/ctpsfcube.par
index 8c3dc69..ab8961c 100644
--- a/src/ctpsfcube/ctpsfcube.par
+++ b/src/ctpsfcube/ctpsfcube.par
@@ -20,7 +20,7 @@
 inobs,    f, a, "NONE",,, "Input event list or observation definition XML file"
 incube,   f, a, "NONE",,, "Input counts cube file to extract PSF cube definition"
 caldb,    s, a, "prod2",,, "Calibration database"
-irf,      s, a, "South_50h",,, "Instrument response function"
+irf,      s, a, "South_0.5h",,, "Instrument response function"
 edisp,    b, h, no,,, "Apply energy dispersion?"
 outcube,  f, a, "psfcube.fits",,, "Output PSF cube file"
 
diff --git a/src/cttsmap/cttsmap.par b/src/cttsmap/cttsmap.par
index c3dfdbf..ba60b32 100644
--- a/src/cttsmap/cttsmap.par
+++ b/src/cttsmap/cttsmap.par
@@ -24,7 +24,7 @@ expcube, f, a, "NONE",,, "Input exposure cube file (only needed for stacked anal
 psfcube, f, a, "NONE",,, "Input PSF cube file (only needed for stacked analysis)"
 bkgcube, f, a, "NONE",,, "Input background cube file (only needed for stacked analysis)"
 caldb,   s, a, "prod2",,, "Calibration database"
-irf,     s, a, "South_50h",,, "Instrument response function"
+irf,     s, a, "South_0.5h",,, "Instrument response function"
 edisp,    b, h, no,,, "Apply energy dispersion?"
 outmap,  f, a, "tsmap.fits",,, "Output Test Statistic map file"
 
diff --git a/src/ctulimit/ctulimit.par b/src/ctulimit/ctulimit.par
index 3852984..3e4b3b6 100644
--- a/src/ctulimit/ctulimit.par
+++ b/src/ctulimit/ctulimit.par
@@ -24,7 +24,7 @@ expcube,  f, a, "NONE",,, "Input exposure cube file (only needed for stacked ana
 psfcube,  f, a, "NONE",,, "Input PSF cube file (only needed for stacked analysis)"
 bkgcube,  f, a, "NONE",,, "Input background cube file (only needed for stacked analysis)"
 caldb,    s, a, "prod2",,, "Calibration database"
-irf,      s, a, "South_50h",,, "Instrument response function"
+irf,      s, a, "South_0.5h",,, "Instrument response function"
 edisp,    b, h, no,,, "Apply energy dispersion?"
 
 #