Realizing the potential of the Dragonfly Spectral Line Mapper: Calibration methods and on-sky performance
Deborah M. Lokhorst, Seery Chen, Imad Pasha, Victoria Purcell, William P. Bowman, Qing Liu, Zili Shen, Aidan MacNichol, Evgeni I. Malakhov, Roberto G. Abraham, Pieter van Dokkum
arXiv:2406.17979v1 Announce Type: new
Abstract: The Dragonfly Spectral Line Mapper is an innovative all-refracting telescope designed to carry out ultra-low surface brightness wide-field mapping of visible wavelength line emission. Equipped with ultranarrowband (0.8 nm bandwidth) filters mounted in Dragonfly Filter-Tilter instrumentation, the Dragonfly Spectral Line Mapper maps H$alpha$, [NII]$lambda$6583, and [OIII]$lambda$5007 line emission produced by structures with sizes ranging from $sim$1 to 1000 kpc in the local Universe. These spatial scales encompass that of the exceedingly diffuse and faintly radiating circumgalactic medium, which is singularly difficult to detect with conventional mirror-based telescope instrumentation. Extremely careful control of systematics is required to directly image these large scale structures, necessitating high fidelity sky background subtraction, wavelength calibration, and specialized flat-fielding methods. In this paper, we discuss the on-sky performance of the Dragonfly Spectral Line Mapper with these methods in place.arXiv:2406.17979v1 Announce Type: new
Abstract: The Dragonfly Spectral Line Mapper is an innovative all-refracting telescope designed to carry out ultra-low surface brightness wide-field mapping of visible wavelength line emission. Equipped with ultranarrowband (0.8 nm bandwidth) filters mounted in Dragonfly Filter-Tilter instrumentation, the Dragonfly Spectral Line Mapper maps H$alpha$, [NII]$lambda$6583, and [OIII]$lambda$5007 line emission produced by structures with sizes ranging from $sim$1 to 1000 kpc in the local Universe. These spatial scales encompass that of the exceedingly diffuse and faintly radiating circumgalactic medium, which is singularly difficult to detect with conventional mirror-based telescope instrumentation. Extremely careful control of systematics is required to directly image these large scale structures, necessitating high fidelity sky background subtraction, wavelength calibration, and specialized flat-fielding methods. In this paper, we discuss the on-sky performance of the Dragonfly Spectral Line Mapper with these methods in place.