************ MMT Binospec ************ Overview ======== This file summarizes several instrument specific items for the MMTO's Binospec spectrograph. Setups and Frame Typing +++++++++++++++++++++++ Unique configurations (setups) are defined by both the grating (``dispname``, FITS ``DISPERS1``) and the slit mask (``decker``, FITS ``MASK``). Frames taken with different masks therefore end up in separate setups (separate ``.pypeit`` files and calibration groups), so that slit traces, pixel flats, and wavelength solutions are never mixed across distinct slit-mask geometries. Pixel flats, trace flats, and illumination flats require the incandescent flat lamp to be on (FITS ``INCAN`` = ``on``), in addition to the arc lamp being off (``HENEAR`` = ``off``) and the screen deployed (``SCRN`` = ``deployed``). Exposures taken with ``INCAN`` = ``off`` are dark/noisy and are not auto-typed as flats. Wavelength Calibration ++++++++++++++++++++++ Templates were created in 2023 that cover the usable range for each of the 3 gratings; the 1000 l/mm template was extended in 2026 to support red central wavelengths. All wavelengths are vacuum. The current template coverage is: ============== ========================== ============== Grating Template file Range (Å) ============== ========================== ============== 270 l/mm ``mmt_binospec_270.fits`` 3825 – 9216 600 l/mm ``mmt_binospec_600.fits`` 4042 – 10047 1000 l/mm ``mmt_binospec_1000.fits`` 3757 – 7211 ============== ========================== ============== For the 1000 l/mm grating, central wavelengths from roughly 4500 Å through 6450 Å are covered with full overlap on both detector sides. Settings near the blue end of the grating range (e.g. central wavelength ~4000 Å) extend slightly below the template's blue limit but should still be usable, since ``full_template`` only requires sufficient overlap to anchor the cross-correlation; better test data are needed to confirm this corner. Bad pixel mask ++++++++++++++ The static bad pixel mask is loaded from FITS files derived from the IDL pipeline calibration data (``badpix_binospec.fits`` plus the hard-coded bad columns and detector trap regions defined in ``bino_mosaic.pro``). This adds roughly 12,500 individual bad pixels per detector, along with bad columns and detector trap region masking, replacing the small set of hard-coded bad columns previously identified from 2019 flat and bias observations. The mask files are distributed with the package as ``static_calibs/mmt_binospec/bpm_binospec_det{1,2}.fits.gz``.