2 Observations and reductions

Our 9 field A and Am stars are bright, slow rotating, and (mostly) slightly evolved objects still located in or very near the Main Sequence strip (Burkhart & Coupry 1991; HIPPARCOS, ESA 1997). Several objects are of special interest: $\rho$ Pup and $\tau$ UMa are metallic-line giants (Gray & Garrison 1989); RR Lyn is a metallic-line SB2 system (Popper 1971); o Peg is a hot Am star with a magnetic field (Mathys & Lanz 1990).

The observing run was in December 1996 with the AURELIE spectrograph (Gillet et al. 1994) at the coudé focus of the 152 cm telescope of the Observatoire de Haute-Provence. The settings are the same as those of Hui-Bon-Hoa et al. (1997, hereafter HBA97), giving a spectral resolution of about 34000 (linear dispersion of 5 Å  mm^-1) and a spectral interval 5495-5620 Å(typical spectra are shown in Fig. 1 of HBA97). The detector was a linear diode array Thomson TH 7832 with 2036 13 by 750 $\mu$m pixels. The integration time varied from 10 minutes to 2 hours to have signal-to-noise ratios of at least 300. Offset level measurements, exposures of a tungsten lamp and of a thorium-argon hollow cathode lamp were regularly performed for calibration purpose. Codes written by M. Spite (1967, 1996 private communication) were used to reduce the spectra (see HBA97).