Extension of the TF relation to higher redshift
Calibration of the line width scaling relations derived from different
techniques with different tracers, as a function of redshift
In order to explore the cross calibration of the HI, long-slit H-alpha
and Sloan Digital Sky Survey (SDSS) linewidth relations, we have been
working together with Jeff Gardner and Andy Connolly of the University
of Pittsburgh, who are members of the SDSS team. In March 2003, we observed
the HI emission from a sample of galaxies with 0.04 < z < 0.09 that are
included in the SDSS spectroscopic survey and for which optical long slit spectra have
already been obtained with the Palomar 5 m telescope. A detection
rate of 85% was achieved; use of the radar blanker proved critical to avoid
RFI from the FAA radars. Total integration times between 25 and 250 minutes were required
in order to achieve an average rms noise of about 0.3 mJy and peak signal-to-noise ratio >6,
depending on the HI content and profile width. Widths have now been extracted and a
comparison is being made of the linewidths measured by different tracers/techniques
and with the results of simulations of the instrumental limitations.
The cross calibration of the optical and radio Tully-Fisher relations
constitutes a major part of Barbara Catinella's Ph.D. research at Cornell.