TY - JOUR
T1 - Observational artifacts of Nuclear Spectroscopic Telescope Array: Ghost rays and stray light
AU - Madsen, Kristin K.
AU - Christensen, Finn Erland
AU - Craig, William W.
AU - Forster, Karl W.
AU - Grefenstette, Brian W.
AU - Harrison, Fiona A.
AU - Miyasaka, Hiromasa
AU - Rana, Vikram
PY - 2017
Y1 - 2017
N2 - The Nuclear Spectroscopic Telescope Array (NuSTAR) launched in June 2012, flies two conical approximation Wolter-I mirrors at the end of a 10.15-m mast. The optics are coated with multilayers of Pt/C and W/Si that operate from 3 to 80 keV. Since the optical path is not shrouded, aperture stops are used to limit the field of view (FoV) from background and sources outside the FoV. However, there is still a sliver of sky (∼1.0 deg to 4.0 deg) where photons may bypass the optics altogether and fall directly on the detector array. We term these photons stray light. Additionally, there are also photons that do not undergo the focused double reflections in the optics, and we term these ghost rays. We present detailed analysis and characterization of these two components and discuss how they impact observations. Finally, we discuss how they could have been prevented and should be in future observatories.
AB - The Nuclear Spectroscopic Telescope Array (NuSTAR) launched in June 2012, flies two conical approximation Wolter-I mirrors at the end of a 10.15-m mast. The optics are coated with multilayers of Pt/C and W/Si that operate from 3 to 80 keV. Since the optical path is not shrouded, aperture stops are used to limit the field of view (FoV) from background and sources outside the FoV. However, there is still a sliver of sky (∼1.0 deg to 4.0 deg) where photons may bypass the optics altogether and fall directly on the detector array. We term these photons stray light. Additionally, there are also photons that do not undergo the focused double reflections in the optics, and we term these ghost rays. We present detailed analysis and characterization of these two components and discuss how they impact observations. Finally, we discuss how they could have been prevented and should be in future observatories.
KW - Nuclear spectroscopic telescope array
KW - Optics
KW - Satellite
U2 - 10.1117/1.JATIS.3.4.044003
DO - 10.1117/1.JATIS.3.4.044003
M3 - Journal article
SN - 2329-4124
VL - 3
JO - Journal of Astronomical Telescopes, Instruments, and Systems
JF - Journal of Astronomical Telescopes, Instruments, and Systems
IS - 4
M1 - 044003
ER -