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Wisconsin Ultraviolet Photo Polarimeter Experiment (WUPPE)
Astro2 WUPPE Halfwave Level 1 Data
Reduced Data: Flux & Polarimetry (Stokes Q & U, & Error) vs Wavelength

05 January 1999
by Marilyn Meade

o Description of the Instrument

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) was one of three ultraviolet (UV) telescopes on the Astro-1 payload which flew aboard the space shuttle Columbia during a nine day mission in December 1990. It was reflown for 16 days in March 1995 on board Endeavour during the Astro-2 mission. WUPPE is a 0.5m f/10 Cassegrain telescope and spectropolarimeter. It obtained simultaneous spectra and polarization measurements, with a spectral resolution of about 16A, from 1450 to 3200A. A set of halfwave plates at 6 different angles provide spectropolarimetric modulation with 16A resolution on point sources through apertures from 6 to 40 arcsec. Calibrations of instrumental polarimetric efficiency, residual polarization, position angle registration, and flux sensitivity were performed by a combination of preflight laboratory measures and in-flight standard star observations. The data are corrected for telemetry errors, thermal background, cosmic ray hits, second order contamination, pointing errors, and instrumental polarization, which is roughly 0.05%.

A detailed description of the instrument is given in Nordsieck et al 1994, SPIE, 2010, 2. See also the WUPPE web site for more information:

http://www.sal.wisc.edu/WUPPE

o Astro-2 WUPPE Level 1 Halfwave Data

Astro-2 WUPPE Level 1 data products include calibrated spectra and polarizations. During the Astro-2 mission WUPPE took 369 observations of 254 objects; some objects have multiple pointings. 112 pointings of 79 targets were taken of WUPPE prime targets. WUPPE also observed the prime targets of the other two UV instruments which yielded good spectra in many cases but generally did not have sufficient signal-to-noise for useful polarization measurements. There were 149 pointings of 90 objects of Hopkins Ultraviolet Telescope (HUT) prime interest and 108 pointings of 85 objects of Ultraviolet Imaging Telescope (UIT) interest.

The data have been processed using methods developed for the ground- based spectropolarimetric data from the Pine Bluff Observatory (PBO) of the University of Wisconsin. This involves summation of equivalent readouts on a particular object, subtraction of background scans, division by the flat field calibration spectra, flux calibration using spectra of known bright stars, polarimetric calibration using data obtained during pre-launch and in-flight observations. For halfwave mode data, the filters are differenced and a Fourier analysis, pixel-by-pixel as a function of filter angle, is done to give Stokes parameters %Q and %U spectra along with an Error spectrum, all consisting of 1024 32-bit data points for each array from about 1450 to 3200A.

WUPPE data analysis and software development takes place at the Univer- sity of Wisconsin Space Astronomy Laboratory (SAL). Much of the WUPPE reduction software is based on a FORTRAN language generalized Reticon detector/spectropolarimeter package (REDUCE) developed at SAL to support ground-based (PBO) and rocket UV spectropolarimetric data. This software package was operating on UNIX based microVAXes for several years and is currently running on Silicon Graphics Indy machines running IRIX 6.3.

Of the 369 WUPPE observations taken during Astro-2, 150 pointings (115 objects) provided some useful polarimetric results and 47 additional pointings (43 objects) provided only flux information (no polarimetric result). The Stokes %Q and %U, and %Error spectra and flux calibrated (Flambda- ergs/cm**2/sec/A) data along with pertinent housekeeping data and data reduction information for the useful Astro-2 target halfwave mode pointings have been written to FITS files and are described in this document.

o WUPPE2 Halfwave Level 1 Data FITS file naming convention

WUPPE2_ObjectID_PointingID_HW.fits (e.g. WUPPE2_PHI-PER_220311_HW.fits)

where

ObjectID = The Mission Target List (MTL) name or the name of the object actually observed. The MTL names are common to the HUT, UIT and WUPPE instruments. For some pointings WUPPE offset from the HUT or UIT target or WUPPE co-pointed with HUT on a specific target in a large UIT field. The ObjectID for those cases is the object WUPPE actually observed as opposed to the MTL Target List name. Appropriate comments are included in the FITS header. See the table below for a list of these offset targets. The number of characters in ObjectID can vary from 3 to 8 characters and may be a mix of numbers and/or alphabetic information and may contain embedded '-'s.

PointingID = a 6 digit number representing the object identification number which was assigned during the mission. Each Astro-2 shuttle pointing had a unique PointingID number. (However, the PointingID number may not be unique for both Astro missions. A small number of PointingIDs used in the Astro-1 mission were also used in Astro-2.)

HW is the Halfwave polarimeter mode.

Note: Astro-2 Target Pointings with either a WUPPE offset from the HUT or UIT target or a co-pointing with HUT in a large UIT field:

Target Pointings with a Polarimetric Result:

Obj-ID   PTG-ID  MTL-Name  P Sp       V    Comments                 
-------- ------- --------  - -------- ---- ------------------- 
JUP/IO   1204-41 JUPITER   H moon          2 fl pr
JUP/IO   1204-51 JUPITER   H moon                          
SK-67174 2253-10 SK-67167  H O9II:    11.7 scat lgt >2100A
SK-68135 2257-11 SK-68137  H B0Ia     11.3 scat lgt >2100A
HD5980   2268-11 NGC346_4  H WR       10.  2 fl pr;scat lgt>2100A 
HD5980   2269-11 NGC346_6  H WR       10.  scat lgt>2100A       
HD36402  4306-10 N51D      U WC       11.4 scat lgt>2100A
SK-69203 4416-10 SN1987A   U B0.7Ia   12.3  
HD68049  4804-10 FSGL_15   U B8/9III  9.7  2 fl pr
HD177999 5109-11 NGC6752   U B9II-III 7.41  
HD177999 5109-12 NGC6752   U B9II-III 7.41 2 fl pr 
HD177999 5109-14 NGC6752   U B9II-III 7.41  
47-TUCBS 5201-12 47-TUC    U B8-9     10.7 scat lgt>2100A    
BD36D367 5302-10 NGC0752   U A0III    9.7  scat lgt>2100A 
M67-F81  5311-11 M67       U B8       10.0            
M67-F81  5311-12 M67       U B8       10.0        
HD268653 5403-12 N4        U B3Iab    10.7 2 fl pr;scat lgt>2100A
SK-69117 6198-10 LMC-BAR   U OB       12.7    

Pointings with Spectra Only, No Polarimetric Results:

Obj-ID   PTG-ID  MTL-Name  P Sp       V    Comments                       
-------- ------- --------  - -------- ---- ------------------  
JUP/IO   1204-20 JUPITER   H moon                            
HD5980   2250-10 NGC346_3  H WR       10.    
HD79548  5101-10 NGC2808   U A0       10.4 
HD177999 5109-13 NGC6752   U B9II-III 7.41  
HD116663 5116-10 OMG-CEN   U B9V      8.80 
BD+37426 5304-11 NGC0752   U F0III    9.87 scat lgt aff
BD373423 5312-11 NGC6791   U K             scat lgt aff 
AZV95    6112-10 SMC-B     U O7.5III  13.9 scat lgt aff      

o Example files and Description of the WUPPE2 Halfwave FITS files

Example FITS files for the Halfwave mode data:

WUPPE2_PHI-PER_220311_HW.fits
WUPPE2_GAM2VEL_220410_HW.fits (flux-only data)

The FITSIO package, version 4.14, written by William Pence at the Goddard Spaceflight Center, was used to generate the FITS files. They were written on a Silicon Graphics Indy running IRIX 6.3.

FITS files including the polarimetry are generally 34560 bytes in length. The flux-only FITS files are generally 11520 bytes.

A WUPPE2 Halfwave Level 1 FITS file looks like the following:

            +-------------------+
            |                   |
            | Primary header    |
            |                   |
            +-------------------+

            +-------------------+
            | Primary data      |
            | Flux (Flambda)    |
            |                   |
            +-------------------+

            +-------------------+
            |                   |
            | Extension Header  |
            |                   |
            +-------------------+

            +-----++----++----++----+
            |Wavel|| %Q || %U ||%Err|
            |     ||    ||    ||    |
            |     ||    ||    ||    |
            |     ||    ||    ||    |
            |     ||    ||    ||    |
            |     ||    ||    ||    |
            |     ||    ||    ||    |
            |     ||    ||    ||    |
            +-----++----++----++----+

The set of basic header information includes the primary array keywords and keywords describing the data arrays, target information, telescope engineering data relative to the observation, and calibration information. A set of comments giving the data reduction history is also included along with a "Special Comments" section. The exact headers of the 2 example files are given below. The primary array data consists of the Flux array (1024 data points-32 bits per data point) in units of ergs/cm**2/sec/A (Flambda). The binary tables extension includes headers and vectors for wavelength (Angstroms) and the Stokes parameters %Q & %U, and the %Error (also 1024 32-bit data points per array). There is no binary table extension for the flux-only FITS files.

For the fluxes, bad data have been zeroed out. For the polarization data, the bad data are when the %Error data have been zeroed out. The %Q and %U data remain (allowing inspection of those data) but should not be used.

o Astro-2 Level 1 WUPPE Halfwave FITS file header

FITS File header(flux & polarimetric data): WUPPE2_PHI-PER_220311_HW.fits

Primary FITS header:

 SIMPLE  =                    T / file does conform to FITS standard             
 BITPIX  =                  -32 / number of bits per data pixel                  
 NAXIS   =                    1 / number of data axes                            
 NAXIS1  =                 1024 / length of data axis   1                        
 EXTEND  =                    T / FITS dataset may contain extensions            
 COMMENT   FITS (Flexible Image Transport System) format defined in Astronomy and
 COMMENT   Astrophysics Supplement Series v44/p363, v44/p371, v73/p359, v73/p365.
 COMMENT   Contact the NASA Science Office of Standards and Technology for the   
 COMMENT   FITS Definition document #100 and other FITS information.             
 COMMENT   FITSIO package v4.14 used                                             
 CRVAL1  =              1354.00 / Wavelength in Angstroms of first pixel         
 CDELT1  =                 2.00 / Number of Angstroms/pixel                      
 CRPIX1  =                 1.00 / Starting pixel number                          
 CTYPE1  = 'WAVELENGTH'         / Wavelength in Angstroms                        
 CUNIT1  = 'angstrom'           / Unit of Wavelength                             
 BUNIT   = 'ERGS/CM**2/SEC/A'   / Unit of Flux (FLAMBDA)                         
 ORIGIN  = 'UW-Space Astronomy Lab' / Creator of FITS file                       
 DATE    = '1998-12-09T17:11:57' / FITS file creation date                       
 DATE-OBS= '1995-03-05'         / Date of Observation (GMT) ccyy-mm-dd           
 OBSERVAT= 'ASTRO-2 '           / Observatory                                    
 TELESCOP= 'WUPPE   '           / Telescope                                      
 INSTRUME= 'SPECTROPOLARIMETER' / Instrument Used                                
 MODE    = 'HW      '           / Halfwave Polarimeter Mode                      
 OBJECT  = 'PHI-PER '           / Object Observed                                
 NAME2   = 'HD10516 '           / Alternate Target Name                          
 ID      = '2203-11 '           / Target ID                                      
 PRIME   = 'WUPPE   '           / Prime Instrument                               
 EQUINOX =              1950.00 / Equinox for coordinates                        
 RA      =                25.13 / Right ascension in degrees                     
 DEC     =                50.44 / Declination in degrees                         
 GMTSTART= '64/20:54'           / GMT start time of observation (dd/hh:mm)       
 METSTART= '03/14:16'           / Mission Elapsed Time start time (dd/hh:mm)     
 EXPOSURE=                997.0 / Useful Exposure Time (seconds)                 
 FRAMETIM=                  0.2 / Frametime for each scan (seconds)              
 SEQ-NUM =                  106 / WUPPE Sequence Number                          
 HVPS    =                 3.70 / High Voltage Power Supply (volts)              
 GAIN    = 'High    '           / Spectrometer Gain (High or Low)                
 THERM   =               -33.10 / Instrument temperature (Centigrade)            
 POSANGLE=               197.20 / Observatory Position Angle                     
 IMCSTATU= '-1      '           / Image Motion Compensation System status        
 COMMENT   IMCS:-1=man disab;0=auto disab;1=enab;2=out of limits                 
 DAYNIGHT= 'Day     '           / Day-Night Status                               
 COMMENT   Day-Night designations: "Night", "Day" (All Night or All Day)         
 COMMENT   "MostN", "MostD" (Mostly Night or Mostly Day), "N/D" or "D/N"         
 COMMENT   (Night into Day, Day into Night, roughly half the time in each).      
 APERTURE=                    8 / Aperture Used                                  
 COMMENT   Ap 8=6"x12";Ap 1=40" diam;Ap 2=4.2" diam                              
 FILTER  =                    6 / Starting Filter Number                         
 COMMENT   Useful data generally are from 1450A-3200A with a spectral            
 COMMENT   resolution of 16A.                                                    
 HISTORY   Data Reduction History                                                
 HISTORY   Wavelength calibration using Aluminum lines (created 4/25/95)         
 HISTORY   Filter mixing fixed for 0.2 sec frametime scans                       
 HISTORY   Remove cosmic ray hits & telemetry errors & deviant scans             
 HISTORY   Remove offsets & thermal background & correct for thermal drift       
 HISTORY   Remove detector background (Astro-2 dtr bkg: created 5/22/95)         
 HISTORY   Apply noise reduction & 2nd order correction(created 3/13/96)         
 HISTORY   For each scan, correct for image motion in pitch & yaw                
 HISTORY   Apply flat field for Astro-2 point source (created 3/21/96)           
 HISTORY   Apply flux calibration: used HST standards & ptg correction           
 HISTORY   (created 4/1/97)                                                      
 HISTORY   Apply Astro-2 high gain instrumental polarization calibration:        
 HISTORY   wuppe2i (created 5/16/96)                                             
 COMMENT   WUPPE Astro-2 flux calibration has a relative flux accuracy           
 COMMENT   of 5% between 1700A and 3000A and 10% outside this range.             
 COMMENT   Due to pointing instabilities, fluxes are not absolute.               

 Binary extension header:

 XTENSION= 'BINTABLE'           / binary table extension                         
 BITPIX  =                    8 / 8-bit bytes                                    
 NAXIS   =                    2 / 2-dimensional binary table                     
 NAXIS1  =                16384 / width of table in bytes                        
 NAXIS2  =                    1 / number of rows in table                        
 PCOUNT  =                    0 / size of special data area                      
 GCOUNT  =                    1 / one data group (required keyword)              
 TFIELDS =                    4 / number of fields in each row                   
 TTYPE1  = 'WAVELENGTH'         / label for field   1                            
 TFORM1  = '1024E   '           / data format of the field: 4-byte REAL          
 TUNIT1  = 'ANGSTROM'           / physical unit of field                         
 TTYPE2  = 'Q       '           / label for field   2                            
 TFORM2  = '1024E   '           / data format of the field: 4-byte REAL          
 TUNIT2  = 'PERCENT '           / physical unit of field                         
 TTYPE3  = 'U       '           / label for field   3                            
 TFORM3  = '1024E   '           / data format of the field: 4-byte REAL          
 TUNIT3  = 'PERCENT '           / physical unit of field                         
 TTYPE4  = 'ERROR   '           / label for field   4                            
 TFORM4  = '1024E   '           / data format of the field: 4-byte REAL          
 TUNIT4  = 'PERCENT '           / physical unit of field                         
 EXTNAME = 'POLARIMETRY'        / name of this binary table extension            
 CALIBRAT= 'wuppe2i '           / Instrumental polarization calibration used     
 AVE-POL =                0.436 / Mean %Pol over entire wavelength region        
 AVE-ERRO=                0.004 / Mean %Error in %Pol                            
 AVE-PA  =                 49.4 / Mean Position Angle (degrees)                  
 COMMENT   The errors given in the error array are the statistical errors        
 COMMENT   based on the residuals of the least squared fit to the 3              
 COMMENT   filter-pair polarimetric data (see section 2.3 of Wolff,              
 COMMENT   Nordsieck & Nook 1996 AJ 111, 856).                                   
 COMMENT   The instrumental polarization stability of WUPPE is +/- 0.04%         
 COMMENT   and the polarization efficiency is Pol/20.                            
 COMMENT   ***IMPORTANT NOTE***                                                  
 COMMENT   **The ERROR array is also being used as a QUALITY array.              
 COMMENT   **For bad/contaminated data, the errors have been set to zero         
 COMMENT   **but the %Q & %U arrays for those wavelengths remain unchanged       
 COMMENT   **to allow inspection of the bad data.                                
 COMMENT   WUPPE Astro-2 instrumental polarization is Q=-0.04% and               
 COMMENT   U=-0.08% (which has been removed).                                    
 COMMENT   Special Comments                                                      
 COMMENT   *2400A "Glitch"*                                                      
 COMMENT   The data between about 2380A and 2420A are bad (& therefore the       
 COMMENT   error array has been set to zero) due to a detector flaw in           
 COMMENT   the "A" polarimetric array.                                           

============================================================================

  FITS File header (flux only data):  WUPPE2_GAM2VEL_220410_HW.fits 

 Primary FITS header:

 SIMPLE  =                    T / file does conform to FITS standard             
 BITPIX  =                  -32 / number of bits per data pixel                  
 NAXIS   =                    1 / number of data axes                            
 NAXIS1  =                 1024 / length of data axis   1                        
 COMMENT   FITS (Flexible Image Transport System) format defined in Astronomy and
 COMMENT   Astrophysics Supplement Series v44/p363, v44/p371, v73/p359, v73/p365.
 COMMENT   Contact the NASA Science Office of Standards and Technology for the   
 COMMENT   FITS Definition document #100 and other FITS information.             
 COMMENT   FITSIO package v4.14 used                                             
 CRVAL1  =              1364.00 / Wavelength in Angstroms of first pixel         
 CDELT1  =                 2.00 / Number of Angstroms/pixel                      
 CRPIX1  =                 1.00 / Starting pixel number                          
 CTYPE1  = 'WAVELENGTH'         / Wavelength in Angstroms                        
 CUNIT1  = 'angstrom'           / Unit of Wavelength                             
 BUNIT   = 'ERGS/CM**2/SEC/A'   / Unit of Flux (FLAMBDA)                         
 ORIGIN  = 'UW-Space Astronomy Lab' / Creator of FITS file                       
 DATE    = '1998-12-18T14:02:38' / FITS file creation date                       
 DATE-OBS= '1995-03-17'         / Date of Observation (GMT) ccyy-mm-dd           
 OBSERVAT= 'ASTRO-2 '           / Observatory                                    
 TELESCOP= 'WUPPE   '           / Telescope                                      
 INSTRUME= 'SPECTROPOLARIMETER' / Instrument Used                                
 MODE    = 'HW      '           / Halfwave Polarimeter Mode                      
 OBJECT  = 'GAM2VEL '           / Object Observed                                
 NAME2   = 'HD68273 '           / Alternate Target Name                          
 ID      = '2204-10 '           / Target ID                                      
 PRIME   = 'WUPPE   '           / Prime Instrument                               
 EQUINOX =              1950.00 / Equinox for coordinates                        
 RA      =               122.01 / Right ascension in degrees                     
 DEC     =               -47.20 / Declination in degrees                         
 GMTSTART= '76/01:42'           / GMT start time of observation (dd/hh:mm)       
 METSTART= '14/19:30'           / Mission Elapsed Time start time (dd/hh:mm)     
 EXPOSURE=                214.0 / Useful Exposure Time (seconds)                 
 FRAMETIM=                  0.2 / Frametime for each scan (seconds)              
 SEQ-NUM =                  433 / WUPPE Sequence Number                          
 HVPS    =                 3.10 / High Voltage Power Supply (volts)              
 GAIN    = 'Low     '           / Spectrometer Gain (High or Low)                
 THERM   =               -33.10 / Instrument temperature (Centigrade)            
 POSANGLE=               161.70 / Observatory Position Angle                     
 IMCSTATU= '1       '           / Image Motion Compensation System status        
 COMMENT   IMCS:-1=man disab;0=auto disab;1=enab;2=out of limits                 
 DAYNIGHT= 'Night   '           / Day-Night Status                               
 COMMENT   Day-Night designations: "Night", "Day" (All Night or All Day)         
 COMMENT   "MostN", "MostD" (Mostly Night or Mostly Day), "N/D" or "D/N"         
 COMMENT   (Night into Day, Day into Night, roughly half the time in each).      
 APERTURE=                    8 / Aperture Used                                  
 COMMENT   Ap 8=6"x12";Ap 1=40" diam;Ap 2=4.2" diam                              
 FILTER  =                    6 / Starting Filter Number                         
 COMMENT   Useful data generally are from 1450A-3175A with a spectral            
 COMMENT   resolution of 16A.                                                    
 HISTORY   Data Reduction History                                                
 HISTORY   Wavelength calibration using Aluminum lines (created 4/25/95)         
 HISTORY   Filter mixing fixed for 0.2 sec frametime scans                       
 HISTORY   Remove cosmic ray hits & telemetry errors & deviant scans             
 HISTORY   Remove offsets & thermal background & correct for thermal drift       
 HISTORY   Remove detector background (Astro-2 dtr bkg: created 5/22/95)         
 HISTORY   Apply noise reduction & 2nd order correction(created 3/13/96)         
 HISTORY   NO correction for image motion in pitch & yaw                         
 HISTORY   Apply flat field for Astro-2 diffuse source (created 3/28/96)         
 HISTORY   Apply flux calibration: used HST standards & NO ptg correction        
 HISTORY   (created 4/1/97)                                                      
 COMMENT   WUPPE Astro-2 flux calibration has a relative flux accuracy           
 COMMENT   of 5% between 1700A and 3000A and 10% outside this range.             
 COMMENT   Due to pointing instabilities, fluxes are not absolute.               
 COMMENT   No useful polarimetry was obtained from this observation.             
 COMMENT   Special Comments                                                      
 COMMENT   Very bright object;Defocussed Image                                   

o The WUPPE2 Target Halfwave Data Set

Polarimetric Results:

150 of 369 pointings (115 targets) have some useable polarization result. (See the Target Observation Log file below for more details on the observations.)

119 of these pointings (89 objects) resulted in polarization measured across the majority of UV wavelengths.

Eleven of these 119 pointings (ten objects) had only two filter pairs observed. During these observations, good data were obtained in only the first two sets of the three halfwave filter pairs. This prevents an independent estimate of the errors. The formal errors have been multiplied by three to give a more reasonable error estimate (this factor comes from empirical evidence by comparing the errors from three filter sets to those with only two filter sets).

Another three of the 119 pointings (three targets) had data where some "Droop" affects were seen. There are positions in Aperture 8 and especially Aperture 1 where part of the spectrum is projected off the edge of the A-array detector (the "Droop" area). Data >~2380A for Ap 1 and >~2800A for Ap 8 can be affected by Droop. "Droopy" scans were not used in the reduction in the affected wavelength regions. Only the B-array data (which are unaffected by Droop) were used for the flux data.

An additional six pointings (of the 119 pointings, five targets) gave very low signal/noise results and should be treated with caution. An additional 31 pointings (26 targets) have significant scattered daylight polarization contamination at wavelengths > 2100A. These data have the error array set to zero for those wavelengths denoting the poor polarization data. (Eight of these 31 pointings (6 objects) also were two filter pair observations.) Scattered light polarization affects were seen in observations of faint targets in the daytime with a sun angle < 90 degrees. See WUPPE2_SCATLGTF_000000_HW.fits for the mean estimated contribution of the scattered sunlight to the flux. It was found from daytime observations of blank sky that the scattered light polarization was about 50%(+-12%) at the solar position angle. Therefore even if the scattered light contribution to the flux is small, the potential contribution to the observed polarization can be significant (e.g. if the scattered light flux is only 1% of the observed flux, that translates into possibly a 0.5% contribution of scattered light polarization to the observed polarization).

Flux Only Results:

In some cases the observation was too short or data from at least two filter pairs were not collected to produce polarization results. The flux calibrated data are provided in these cases (47 of 369 pointings-43 targets). Of the 47 flux only pointings, 18 pointings (16 targets) have some amount of contamination due to scattered light flux. See WUPPE2_SCATLGTF_000000_HW.fits for the mean estimated contribution of the scattered light to the flux.

No Useful Results:

In 172 of the 369 target pointings (128 targets) the object was never in the aperture or was swamped by scattered sunlight or there were other problems. No data are provided in these cases.

Estimated Scattered Sunlight Flux:

This spectrum is the mean estimate of the scattered light flux which was detected by WUPPE when the sun angle was <90 degrees. It was created by coadding the flux from ten daytime targets where WUPPE offset from the target and three pointings where WUPPE observed blank sky during the day. The coadded data were divided into the WUPPE flux of the moon, smoothed, then multiplied by the lunar flux. The level of this flux can vary by about a factor of 2 (higher or lower). The FITS file for this mean estimated scattered light flux is named: WUPPE2_SCATLGTF_000000_HW.fits (where 000000 has been assigned as the PointingID for this data set).

See the WUPPE2 target observation log at the end of this document for more specific information on the target observations.

o Software

The programs polfitsread.f and fluxfitsread.f were written to verify the contents of the Astro-2 WUPPE Level1 FITS files. They also use the FITSIO v4.14 software package. These programs create the ASCII dump files described in the section below.

o Postscript Files

Postscript files have been provided in which the Flux (Flambda), binned percent Polarization and binned Position Angle have been plotted. Two sets of postscript files have been provided for each pointing. In one set, the polarization data are binned to a specific wavelength interval (e.g 100 Angstrom bins). In the other set, the polarization data are binned to a constant error (e.g. 0.05% error). The naming convention is the same as above except ".fits" has been replaced by "a.ps" or "e.ps", for angstrom binning or error binning respectively. For the daylight contaminated pointings, the flux plots include the the observed flux, the estimated scattered light flux (given in WUPPE2_SCATLGTF_000000_HW.fits), and the observed flux minus the mean estimated scattered light flux. (NOTE: The FITS files contain only the observed flux.)

e.g.
WUPPE2_ObjectID_PointingID_HWa.ps or WUPPE2_ObjectID_PointingID_HWe.ps
WUPPE2_PHI-PER_220311_HWa.ps (40A binning)
WUPPE2_PHI-PER_220311_HWe.ps (0.032% error binning)

For the flux only pointings 16 postscript files have been provided in which the flux of 47 pointings and the estimated scattered light flux have been plotted. The file names are:

                                        Contains plots of:
                                     PointingID      Object Name
  WUPPE2_HW_FLUX1.ps                  0901-10          BET-CAS
                                      2203-10          PHI-PER
                                      2204-10          GAM2VEL

  WUPPE2_HW_FLUX2.ps                  3115-10          HD200775
                                      4211-11          NGC7023
                                      4211-12          NGC7023

  WUPPE2_HW_FLUX3.ps                  4511-10          SK66-19
                                      4511-20          SK66-19
                                      0000-00          SCATLGTF

  WUPPE2_HW_FLUX6.ps                  1204-20          Jupiter-Io
                                      2250-10          HD5980
                                      2828-10          HD57682

  WUPPE2_HW_FLUX7.ps                  2856-10          HD86466
                                      2916-11          0839+399
                                      3223-10          AM-Her

  WUPPE2_HW_FLUX8.ps                  4410-11          Vela-P1
                                      4458-11          Vela-F
                                      4460-10          Vela-H

  WUPPE2_HW_FLUX9.ps                  5101-10          HD79548
                                      5109-13          HD177999
                                      5116-10          HD116663

  WUPPE2_HW_FLUX10.ps                 6202-10          NGC2841
                                      6246-10          NGC4736
                                      6406-10          NGC4449

  WUPPE2_HW_FLUX11.ps                 7303-11          NGC3310
                                      7305-10          NGC2903
                                      7316-10          NGC5253

  WUPPE2_HW_FLUX12.ps                 7342-13          0833+652
                                      8116-23          NGC4151
                                      8202-21          NGC1068

Daylight contaminated pointings Plots include the observed flux, the mean estimated scattered light flux (given in WUPPE2_SCATLGTF_000000_HW.fits), and the observed flux minus the mean estimated scattered light flux. NOTE: The FITS files contain only the observed flux. (In some cases (e.g. 4413-12 CygLoopB), the mean scattered light flux estimate is too high. As stated earlier, the scattered light flux level can vary by a factor of 2.)


                                        Contains plots of:
                                     PointingID      Object Name

  WUPPE2_HW_FLUX4.ps                  3270-11          NOVA-AQL
                                      3401-10          EG-AND
                                      3407-12          HM-SGE

  WUPPE2_HW_FLUX5.ps                  3411-11          V1329CYG
                                      3430-11          BF-CYG
                                      4593-11          SK67-90

  WUPPE2_HW_FLUX13.ps                 2251-11          SK80
                                      2564-11          Wolf1346
                                      5102-10          NGC0362

  WUPPE2_HW_FLUX14.ps                 4413-10          CygLoopB
                                      4413-11          CygLoopB
                                      4413-12          CygLoopB

  WUPPE2_HW_FLUX15.ps                 4442-10          CygLoopD
                                      4470-11          CygLp-P8
                                      4473-21          CygLp-11

  WUPPE2_HW_FLUX16.ps                 5304-11          BD+37 426
                                      5312-11          BD+37 3423
                                      6112-10          AZV95

o ASCII dumps of WUPPE2 Halfwave FITS files

ASCII dumps of each of the WUPPE target Halfwave FITS files have also been provided. Each ASCII dump file is named:

WUPPE2_ObjectID_PointingID_HW.dump (WUPPE2_PHI-PER_220311_HW.dump)

with the Object ID and Pointing ID as defined above. These files are the output of the programs polfitsread.f (for flux & polarimetric data fits files) and fluxfitsread.f (for flux only fits files).

o WUPPE Astro-2 Prime Target Observing Log

                          Field descriptions
Name    ZET-TAU           - Target Name (in Mission Target List)
ID      2209-10           - Target ID
Ref     J22               - Publication Reference (J=Refereed Journal,
                            C=Conference Proceedings,A=AAS Abstract)
                            (see www.sal.wisc/edu/WUPPE/pubswuppe.html)
P       W                 - Prime Instrument (H=HUT,U=UIT,W=WUPPE)
Sp      B4IVe             - Spectral Type
V       3.0               - V magnitude
Pol     0.629             - Mean %Polarization over approx. 1450-3200A
Error   0.002             - Mean Error in %Pol over approx. 1450-3200A
PA      31.1              - Mean Position Angle (degrees) over approx. 1450-3200A
Exp     1085              - Total Useable Exposure Time (secs)
RA      83.66             - Right Ascension in degrees
Dec     21.11             - Declination in degrees
JD      9785.05           - Julian Date - 2,440,000
MET     06/06:37          - MET start time of observation
GMT     67/13:15          - GMT start time of observation
D/N     Night             - Day/Night Status
Ap      8                 - Observe Aperture (8=6"x12";1=40")
IMC     1                 - IMC Status (-1=man.disab;0=auto-disab;1=enab;
                            2=out of limits)
Red-Comments  low gain    - Data Reduction Comments
==============================================================================

Summary of Astro-2 WUPPE Observations:

  369 total WUPPE Astro2 pointings

  119 pointings (89 objects) resulted in polarization measurement across 
      majority of UV wavelengths.
      (11 of these ptgs (10 obj) had only 2 filter pairs observed; the 
        errors were multiplied by 3)
      (3 of these ptgs (3 obj) had some DROOP affects >~2370A)
      (6 pointings (5 obj) gave very low S/N results (error over entire 
         wavelength region >0.9%))
   31 pointings (26 obj) have daylight contaminated data >~2100A
      (8 of these ptgs (6 obj) had only 2 filter pairs observed; the 
         errors were multiplied by 3)
   --
  150 pointings (115 obj) with some polarization result

   29 pointings  (27 obj) were spectrum only
   18 pointings  (16 obj) were spectrum only & contaminated by scattered daylight
   --
   47 pointings  (43 obj) with flux only result

  172 pointings  (128 obj) were scattered light only, object not in aperture, 
        or some other problem
      (no useful result)

==============================================================================

The ASTRO-2 WUPPE OBSERVATION LOG has been extracted to a separate file for ease of access.

o WUPPE Reference List

see www.sal.wisc.edu/WUPPE/pubswuppe.html for the latest list of WUPPE references.

o Further Information

To request copies of relevant WUPPE documents, preprints/reprints, bibliography, or general questions, please contact Marilyn Meade at the UW Space Astronomy Laboratory, Chamberlin Hall, 1150 University Avenue, Madison, WI 53706, telephone (608) 263-4678, or by email at meade@sal.wisc.edu. See also the WUPPE Web site: http://www.sal.wisc.edu/WUPPE

This information was provided by Marilyn Meade of the WUPPE project. Modifications as pertaining to MAST are italicized.