The authors present 288 ISOPHOT observations of 183| young stellar objects.

The data set consists on:

• AAP data structure files as produced by PIA 10.0 and the same in FITS format.

A detailed report is available here.
 

List of corrected caveats related to the observing modes involved in the present work::

• GENERAL CAVEATS FOR ISOPHOT
  • Signal Transients (ISOPHOT HB chapter 4.2.3 and OLP caveat 10.7)

    As described in the data processing report a flux dependent transient correction on all C100 data using an IDL routine is applied. For details of the algorithm see del Burgo et al. (ESA SP-511, 2002). The correction noticeably improved the results at intermediate fluxes (~ 2-16 Jy). In the case of the C200 detector signal transients are small and negligible compared to other error sources (P. Héraudeau, private communication).

  • Incomplete error propagation (ISOPHOT HB OLP caveat 10.3)
    • Mini-map observations:
      Individual error bars for each measurement are obtained as the standard deviation of flux values obtained by different detector pixels. In parallel the empirical total uncertainty for the whole ensemble of 555 normal star measurements are also assessed by computing the standard deviation of the [measured - predicted] flux differences. The two kinds of errors were in reasonable agreement. The results confirmed that the main components of the total uncertainty are instrumental noise and sky confusion noise. In the case of C200 measurements the dominant factor is the sky confusion noise.
    • Scan and sparse map observations:
      Formal flux uncertainty values were provided by the IDL procedure which fitted the measured fluxes of the different pixels as a function of the footprint values (see data processing report).

• CAVEATs for DETECTORS C100 and C200
  • Restricted signal non-linearity correction (ISOPHOT HB OLP caveat 10.10)
    • Mini-map and scan observations:
      As a last step of the processing scheme an empirical flux-dependent correction is performed which - signals and fluxes are approximately proportional - corrects to a large extent for the possible artifacts related to the restricted range of signal non-linearity correction.
    • Sparse map observations:
      Tests on normal star observations performed in sparse map mode show no obvious systematic photometric discrepancies as a function of stellar flux, indicating that the restrictions in the signal non-linearity correction do not lead to noticable quality decrease in the present sparse map data set.

  • Responsivity Drifts (ISOPHOT HB chapter 4.2.4 and OLP caveat 10.8):

    In those cases when enough data points were available the long term drift evolution was fitted with a 2nd order polynomial and subtracted from the observation. This correction improved the photometric results significantly.

  • Background Subtraction

    Mini-map, scan and sparse map observations:
    The flux extraction method adopted in our data reduction scheme is based on a simultaneous fitting of the background level and the source flux using the point-spread function.

  • FCS calibration quality restricted

    All C100 and C200 observations of the present data set were observed after revolution 94.

  • Aperture photometry from surface brightness maps

    In our processing the flux was reconstructed with the help of the detector footprint shape.

• CAVEATs for DETECTORS P1 & P2 & P3
  • Background Subtraction

    Background signal was subtracted with method adapted to the specific observing mode.