Frequently Asked Questions

Where do I get TUES archival data?

• See the obtaining TUES data web page.

Can you explain the TUES file naming conventions?

• Basically names are of the form
  TUESnnnn_m_o.fits where the target ID ("nnnn") is a special 4-digit target identification number and the observation number ("m") refers to the order in which the exposures (for a given target) were obtained. A third number ("o") indicates several pointings were obtained during a single observation (sometimes to improve the alignment of the telescope). A "_PH" denotes an integration from single photon events recorded onboard but integrated after the mission. See also the TUES file naming conventions described in the data products page.

How accurate are the calibrated flux values?

• A HST archive model of G191B2B http://garnet.stsci.edu/STIS/models/tables/g191b2b_mod_002.tab" was used as a reference for the absolute flux calibration. The calibration was additionally checked with a model of BD +28°4211 (R.Napiwotzki). We guess an accuracy of ±10% for the flux calibration. This is valid, if the object was fully centered within the diaphragm. There are, however, some observations for which the object was not completely centered. The reasons are probably due to temperature drifts of the telescope causing a shift of the alignment. In some cases also slightly wrong coordinates of the target might have led to a decentralization.