Sensitive far-IR survey spectroscopy: BLISS for SPICA

C. M. Bradford, Matt Kenyon, Warren Holmes, James Bock, Timothy Koch, William D. Duncan, Wayne S. Holland, Stafford Withington, Jonas Zmuidzinas
2008 Millimeter and Submillimeter Detectors and Instrumentation for Astronomy IV  
We present a concept for BLISS, a sensitive far-IR-submillimeter spectrograph for SPICA. SPICA is a JAXA-led mission featuring a 3.5-meter telescope actively cooled to below 5K, envisioned for launch in 2017. The lowbackground platform is especially compelling for moderate-resolution survey spectroscopy, for which BLISS is designed. The BLISS / SPICA combination will offer line sensitivities below 10 −20 W m −2 in modest integrations, enabling rapid survey spectroscopy of galaxies out to
more » ... axies out to redshift 5. The far-IR fine-structure and molecular transitions which BLISS / SPICA will measure are immune to dust extinction, and will unambiguously reveal these galaxies' redshifts, stellar and AGN contents, gas properties, and heavy-element abundances. Taken together, such spectra will reveal the history of galaxies from 1 GY after the Big Bang to the present day. BLISS is comprised of five sub-bands, each with two R ∼ 700 grating spectrometer modules. The modules are configured with polarizing and dichroic splitters to provide complete instantaneous spectral coverage in two sky positions. To approach background-limited performance, BLISS detectors must have sensitivities at or below 5 × 10 −20 W Hz −1/2 , and the format is 10 arrays of several hundred pixels each. It is anticipated that these requirements can be met on SPICA's timescale with leg-isolated superconducting (TES) bolometers cooled with a 50 mK magnetic refrigerator.
doi:10.1117/12.790156 fatcat:xglbhkfdpbcg7b66rdvgzfkmta