CIRPASS Demonstration Science Results

CIRPASS, the near-infrared integral field unit (IFU) spectrograph constructed by the Institute of Astronomy (University of Cambridge), recently completed a very successful 9-night Demonstration Science run on Gemini South under the leadership of Ian Parry and Andrew Bunker (IoA). This represents the first use of a near-IR IFU on an 8m-class telescope.

A number of science programs were conducted: 

• 2D mapping the of the velocity structure emission line gas in the z=1.2 radio galaxy 3C324 (previously also observed with the GMOS IFU)
• A study of star formation and kinematics in two z=1 galaxies using H-alpha
• A deep survey of damped Lyman-alpha systems: two targets at z=1.5 at H-alpha, one at z=3 at [OII] (also previously observed with GMOS searching for Ly-alpha). It is expected that after complete processing these data will produce a detection or the strongest limits to date on star formation in these systems.
• A high signal-to-noise study of the Einstein cross q2237+03 (a lensed QSO at z=1.7), comparing the narrow and broad line components in the four images to investigate "clumping" in the dark matter distribution of the foreground lensing galaxy.
• A spatially-resolved study of a giant lensed arc at z=1.6 in [OII] and H-beta emission. 
• An investigation of young star clusters in NGC1140 to measure the ages of several clusters in the central starburst region.
• Measurement of velocity dispersions of Galactic star clusters (including M30, the quintuplet cluster, and around Sgr-A).
• During commissioning, observations of several bright targets were made for system characterisation and calibrations, including: a partial map of the Eagle nebula in multiple emission lines, the planetary nebula NGC6369, the planet Uranus, and the SN1987a shells in Paschen-alpha.

The example data shown left is from the z=1.2 radio galaxy 3C324. (Dispersion runs horizontally, spatial direction is vertical; each of the 500 IFU lenslets produces a spectrum 2 pixels high). The preliminary processing (basic sky subtraction and cosmic ray rejection) of this single 20 minute exposure shows a very clear detection of the [OIII]500.7nm emission line (centre of the frame). More data on 3C324 and the other science programs can be found at the IoA CIRPASS results page.

As with all Gemini Demonstration Science data, it is intended that these datasets will be made publicly available within 2 months. Further details will be provided at that time. 

Last update 15 August 2002; Phil Puxley