Tuesday, April 15, 2014

Swift Supernova photometry version B14.1.dat format

I've made a new version of my UVOT supernova photometry code, I think fixing the upper limit issues with version 13.2 and fixing some overestimated errors when doing aperture corrections.  Before going through all the supernovae (yet again!) I would like to finalize the final output format that will be used by others.  Fits tables can be shared which provide all the nitty gritty details of source counts, coincidence loss correction factors, and such, but I would like these data text files to contain 90% of what anyone else would want.  Below is a sample for SN2005cf.  Suggests are welcome, especially if other columns would be useful outputs.

################
# SN2005cf magnitudes from Swift UVOT                                                       
# generated Mon Mar 31 22:35:16 CDT 2014 using version 2014.1                                        
# of Peter Brown's photometry pipeline                                                     
# and version Swift_Rel4.2(Bld31)_25Nov2013 of HEASOFT                                                     
#                                                                                        
# Data comes from the Swift Data Center                                                  
# A 5 arcsec aperture is used to measure the counts for the coincidence loss correction, 
# a 3 or 5 arcsec source aperture (based on the error) was used for the aperture photometry
# subtracting off the galaxy count rate in a template image  (if available),             
# and applying an aperture correction as appropriate (based on average psf in Swift CALDB)
# and zeropoints from Breeveld et al. (2011) which update Poole et al. (2008)            
# including a time-dependent sensitivity loss                                            
# to put the magnitudes on the UVOT photometric system described in that paper.          
#
#  Brown, P. J., Holland, S. T., Immler, S., et al. 2009, ApJ, 137, 4517
#  Brown, P. J., et al. 2014, Ap\&SS
#  Breeveld, A. A., Landsman, W., Holland, S. T., et al. 2011, in AIP Conf. Proc. 1358,  
#     Gamma-Ray Bursts 2010, ed. J. E. McEnergy, J. L. Racusin, & N. Gehrels                
#     (Melville, NY: AIP), 373; arXiv:1102.4717                                             
#  Poole, T. S., Breeveld, A. A., Page, M. J., et al. 2008, MNRAS, 383, 627
#                                                                                        
#                                                                                          
# Original reference for Swift observations:                                       
# Wang, X., et al. 2009, ApJ, 697, 380                                                                                   
# The data have been reanalyzed with the revised zeropoints            
# and sensitivity corrections of Breeveld et al. 2011. 
# Use of this final version should also reference Brown et al. 2014, Ap\%SS, submitted                             
#                                                                                          
# The underlying galaxy had the following count rates                                      
# in a 5 arcsec aperture at the source position 
# (missing filters list 0 but used a background region similar to the SN ):                
# Galaxy count rates in 5" aperture
# V          0.202       0.127865
# B          0.101       0.194355
# U          0.205      0.0936644
# UVW1       0.052      0.0255154
# UVM2       0.029     0.00996702
# UVW2       0.005      0.0109126
#                                                                                          
# There are no known issues with this photometry.                                          
# b and v data consistent with BV data from
# Pastorello et al. 2007, MNRAS, 376, 1301 S corrected mags
# S corrected mags from Wang et al. 2009, ApJ, 697, 380
                                              
# MJD Mag MagErr 3SigMagLimit 0.98SatLimit Rate RateErr ApSize Exposure DateObs Tstart Tstop                                   
#                                                                                          
# uvw2                                                                                     
53525.0428  17.794   0.114  20.315  11.085   0.683   0.072   3.000        283.226   2005-06-04T00:59:12     139539551.990120        139539839.754778

#                                                                                          
# uvm2                                                                                     
53525.0466    NULL    NULL  19.679  10.555   0.044   0.021   3.000        212.361   2005-06-04T01:05:21     139539920.975120        139540136.738778


################



The final format is now:

# Filter MJD[days] Mag MagErr 3SigMagLim 0.98SatLim[mag] Rate[c/s] RateErr[c/s] Ap[arcsec] Frametime[s] Exp[s] Telapse[s]
#                                                                                          
UVW2     53525.0428  17.794   0.114  20.315  11.085   0.683  0.1   3.000      0.0110322     283.23     287.76

2 comments:

  1. Date-Obs and Tstart are redundant. Maybe drop Tstart (in the archaic units of mission-elapsed seconds) and replace Tstop with a human readable Date-End ?

    ReplyDelete
  2. put the exposure time for the template observations in the header?

    ReplyDelete