ZEUS-2


New spectrometer that is based on ZEUS, but...
  • "Dry" cryostat including pulse-tube cooler and dual stage ADR
  • Three arrays of transition-edge-sensed bolometers
  • Spatial imaging capabilities

ZEUS-2 is being constructed for use on CSO, APEX, and JCMT.


Broad Wavelength Coverage
  • Same grating, now used from 3rd to 9th order
  • Enables simultaneous imaging in up to 5 lines for extended sources
  • Enables observations of redshifted fine-structure lines over wide redshifts                 - [CII]: z ~ 0.2 to 3                                                                                                  - [OIII]: z ~ 1.2 to > 5                                                                                              - [OI]: z ~ 2.5 to > 5                                                                                                                                                                


                                                
Cyrogenics
  • Pulse Tube Cooler
        - Cyromech PT-407
        - Dual stage
        - 18 W @ 45 K
        - 200 mW @ 3.5 K
  • ADR
        - Janis dual stage
        - 7 uW @ 1 K (24 hr)
        - 180 nW @ 100 mK 		Optics
  • R2 Echelle
        - L ~ 35 cm
        - 9th order 200 mm
        - 8th order 230 mm
        - 5th order 350 mm
        - 4th order 450 mm
        - 3th order 610 mm 



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Focal Plane Array
  • Upgrading to (3) NIST 2-d TES bolometer arrays
  • Back short tuned
  • 5 lines in 4 bands simultaneously                                      - 215 µm (1.5 THz)                                                         - 350 µm (850 GHz)                                                        - 450 µm (650 GHz)                                                        - 625 µm (475 GHz)
  • Imaging capability (9-10 beams)








Imaging Capabilities
  • Astrophysics                                                                    - [CI] line ratio: Strong contraints on  T                            - 13Co (6-5) line: Strong constraints on CO opacity              - [NII] line: Cooling of ionized gas, and fraction of [CII] from ionized media
  • Mapping advantages                                                         - Spatial registration "perfect"                                         - Corrections for telluric transmission coupled


Redshift Coverage
  • ZEUS detects [CII] from z ~ 1.1 to 2.1 (350 and 450 µm windows) --> Covers the peak in the star-formation rate per co-moving volume
  • ZEUS-2 expands [CII] coverage to z~ 0.25 to 3 --> Straddles the peak tracing the star formation history of the Universe from 11 Gyr ago to the current epoch
  • Other lines accesible as well:
  • [OI] 63 µm: PDRs UV field strength
  • [OIII] 88 µm: UV field hardness
  • [NII] 122 and 205 µm: ne traces, [CII] from HII regions


Red: ZEUS
Blue: ZEUS-2