Instrumental Broadening Of The SPOL Spectropolarimeter At The University Of Arizona

The Ground-based Observational Support of the Fermi Gamma-ray Space Telescope is conducted by the University of Arizona using the 2.3m Bok and 1.54m Kuiper telescopes operated by the Steward Observatory (SO). This program monitors blazar sources with spectroscopic (among others) observations. Yet, the instrumental broadenings for the different slit widths used in the spectra, are unavailable (the widths range from 2.0 to 12.7 arcsec). Using quasi-simultaneous spectroscopic observations of the blazar 3C 273 between the SO, Observatorio Astrofísico Guillermo Haro (OAGH), and Observatorio Astronómico Nacional San Pedro Mártir (OAN-SPM), we can provide an estimation of the instrumental profile for two of the slit widths. Since the instrumental broadening and the slit width are directly proportional, we were able to estimate the instrumental broadening for all six slit widths used at the SO. We found significant variations between the instrumental profiles, emphasizing the need to correct the instrumental broadening for each aperture.