SFR catalogue

Warning about total SFRs

As of 09/10/05 a problem with the photometry for duplicate objects was discovered and new total SFRs have been posted. Note that even the fiber SFRs for the unclassed galaxies was affected, hence we recommend anyone with older files to update the SFR files.

Summary

This catalogue contains star formation rate estimates for galaxies in the DR4 obtained as described in Brinchmann, J. et al 2004, "The physical properties of star-forming galaxies in the low-redshift Universe ". Please pay attention to the cautions before using the catalogue

About the catalogue

The catalogue contains all galaxies we have examined in the DR4. It is thus a super-set of the galaxies used in Brinchmann et al (2004). This means that the user must show some caution in using the catalogue. In particular it is not advisable to use any SFRs measured for galaxies that do not have a stellar mass >10^5 in the stellar mass catalogue - because of the way SFRs are estimated for AGNs and Composites this would leave you with a biased sample.

In some cases the aperture corrections do fail. These have not been removed from this catalogue as it may be useful to know about these. They can almost always be indentified as galaxies where the mode and average estimate of the SFR differ by more than a factor of 20.

The cosmology used for all below is h=0.7, omega_M=0.3 and omega_L=0.7.

As discussed by Brinchmann et al (2004) we use the full likelihood distributions of the SFRs in our calculations, but for compactness we have here summarised these into medians, 2.5, 16, 84 and 97.5 percentiles as well as the mode and average of the distributions. This suffices for most applications. If you want access to the full likelihoods, get in touch with jarle at astro dot up dot pt.

Scalings for the aperture corrections

The use of spectrophometric magnitudes should be clarified. Each spectrum is analysed from the FITS file provided by the SDSS and this has an associated magnitude which might differ somewhat from the fiber magnitude provided by the photo pipeline. In general the agreement for the colours is excellent, but there are slight offsets (and a few substantial ones) in the normalisation. This is not a major cause of concern, but throughout we have calculated SFRs relative to the specotrophotometric magnitudes (see this link for details about these). This ensures that the magnitudes we use when scaling to total SFRs are sensible (although the aperture corrections will of course occasionally fail!).

Whenever a magnitude was not possible to measure from the spectrum (gap in the spectrum, outside the spectral coverage etc.) we have replaced these using the photo fiber magnitudes - utilizing the fact that the colours match very well between the (reddening corrected) fiber magnitudes and the spectrophotometric magnitudes. This is also how we calculate appropriate z-band magnitudes to estimate the stellar mass within the fiber.

Files available

The full summarised data is available in the binary FITS tables with select columns also included in the text files below.

• sfr_fib.fit.gz. FITS binary table containing the results for the log SFR inside the fibre. The columns are as follows:

    MEDIAN - The median of the likelihood distribution for Log SFR
    P16    - 16% c.f. level of same
    P84    - 84%
    P2P5   - 2.5%
    P97P5  - 97.5%
    MODE   - Mode of likelihood distribution - discrete so binning
             sensitive.
    AVG    - Average of distribution - somewhat binning sensitive
  

• sfr_tot.fit.gz. FITS binary table containing the results for the total log SFR. Columns as above.
• specsfr_fib.fit.gz. FITS binary table containing the results for log SFR/M* estimate inside the fibre. Columns as above.
• specsfr_tot.fit.gz. FITS binary table containing the estimate of the total log SFR/M*. Columns as above.
• sfr_info.fit.gz. FITS binary table containing various information about the SFR files. The columns are as follows:

    PLATEID - SDSS Spectroscopic plate ID
        MJD - MJD of observations
    FIBERID - Fiber ID of observations
      CLASS - The classification of the object (1=SF, 2=Low S/N SF,
              3=Composite, 4=AGN, -1=Unclassifiable)
         RA - The RA of the object from the latest Photo reductions
        DEC - The DEC of the object
    PLUG_RA - The RA used for the fiber plugmap
   PLUG_DEC - The DEC used for the fiber plugmap
        LGM - The stellar mass estimate (log M*) used for the total SFR/M*
     LGMFIB - The stellar mass estimate used for the fibre SFR/M*
  

• sfr_info.txt.gz. Text file containing some of the above information in ASCII format. The columns are (notice that medians were added 26/03/07):

   PLATEID - SDSS Spectroscopic plate ID
        MJD - MJD of observations
    FIBERID - Fiber ID of observations
      CLASS - The classification of the object (1=SF, 2=Low S/N SF,
              3=Composite, 4=AGN, -1=Unclassifiable)
    FIB_P16 - The 16% c.f. level of the fibre log SFR likelihood distribution
   FIB_MODE - The model of the same
    FIB_MED - The median of the same
    FIB_AVG - The average of the same
    FIB_P84 - The 84% c.f. level
  
  Then the same for total log SFR
  
  Then the same order for the log SFR/M* inside the fibre
  
  Then the same order for the log SFR/M* total
  
  Then
        LGM - The stellar mass used for the total SFR/M* estimates 
     FIBLGM - The stellar mass used for the fibre SFR/M* estimates
  

  The fortran format used to print each line in this file is

  (I4,1X,I5,1X,I3,1X,I2,2X,16(F9.5,1X),F8.4,1X,F8.4)