next up previous
Next: Redshifts and Line Luminosities Up: Optical Observations of NVSS 2146+82 and its Environs Previous: Photometric Observations

Spectroscopic Observations

Optical spectra of NVSS 2146+82 were obtained at Kitt Peak National Observatory on 9 December 1996. The spectroscopic observations were made with the RC Spectrograph on the KPNO Mayall 4-meter telescope. The detector in use was the T2KB CCD in a 700 tex2html_wrap_inline1372 2048 pixel format. All exposures were made with a 1'' slit width and a 527 lines/mm grating. The spectral resolution, measured using unresolved night sky lines, is ~ 3.4 . The data were reduced using the standard IRAF reduction tasks. The extracted spectra were wavelength calibrated using a solution determined from the spectrum of a HeNeAr comparison source. Finally, spectrophotometric calibration was applied using a flux scale extrapolated from several standard star spectra.

Spectra of candidate galactic companions to NVSS 2146+82 (see 3.5 below) were obtained with the HYDRA multi-fiber positioner and the Bench Spectrograph as part of the WIYN6 Queue Experiment over the period of 14-22 September 1998. The T2KC CCD was used as the spectrograph detector in its spatially binned 1024 tex2html_wrap_inline1372 2048 pixel mode. All exposures were made with the red fibers, the Simmons camera, and a 400 lines/mm grating. The spectral resolution in this configuration is ~ 4.5 .

We calculated an astrometric solution for the KPNO 4-m frame of the NVSS 2146+82 field using positions for stars in the frame taken from the USNO A1.0 catalog ([Monet et al. 1996]). Using this solution, we derived positions with the accuracy required by the HYDRA positioner for our target galaxies. Due to fiber placement restrictions and the density of our target galaxies on the sky, we were only able to place 46 fibers on targets. The remaining 50 fibers were randomly placed on blank sky, and they were used during the reduction process for night sky subtraction.

The nine 30 minute program exposures were reduced using the IRAF DOHYDRA script. The weather conditions during the last two nights were poor, and the spectra from these nights were not usable. Therefore the final spectra were obtained by co-adding only the data from nights one and two, a total of two hours of integration.

 

6 The WIYN Observatory is a joint facility of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories.


next up previous
Next: Redshifts and Line Luminosities Up: Optical Observations of NVSS 2146+82 and its Environs Previous: Photometric Observations


Fri Feb 4 16:02:06 EST 2000