MUSTANG

MUSTANG is a 64 pixel bolometer array which has been commissioned on the GBT for use at 90 GHz. Proposals will be accepted in the June 1 2009 deadline for Fall/Winter 2009 (trimester 09C) observing on the GBT. Proposers are not required to collaborate with the instrument team.

Some basic performance information is as follows:

As of March 2009, the demonstrated sensitivity of MUSTANG on the GBT yields a 0.4 mJy RMS in one hour of integration time mapping a 3'x3' region. The noise scales as the square root of the integration time up to at least several hours; and the noise increases with the square root of the area covered for larger areas. Mapping smaller areas is not efficient in terms of noise performance. For significantly larger areas faster scanning can be used which will reduce the noise by up to 35%. Proposals must explicitly state a target map RMS in order to be evaluated for scheduling.
Extended emission on scales of 30" to a few arcminutes can be imaged with reasonable fidelity, but faint emission more extended than this may be difficult to detect. Bright emission (20 mJy/beam or more) is easily reconstructed over scales of many arcminutes. The angular resolution of MUSTANG on the GBT is tyipcally 9" (FWHM) and the instantaneous field of view is 40"x40".
Allowing for weather and calibration and observing overheads, the typical observing efficiency realized on the telescope is 50%.
Daytime observing at 90 GHz is currently not advised. The changing solar illumination gives rise to thermal distortions in the telescope structure which make calibrating 90 GHz data extremely difficult.
Further sensitivity improvements of a factor of two or more may be realized (due to GBT surface improvements and a new detector array) but cannot be relied upon for 09C observing.

A few images from early science and commissioning observations are shown below.

Please contact Brian Mason (bmason - nrao - edu) with further questions.

Links

MUSTANG+GBT 3mm 5'x10' map of the Orion S/KL Region on 3 Color Scales

MUSTANG+GBT 90 GHz map of Orion on 3 color scales emphasizing the dynamic range and sensitivity to extended structure that has been achieved. These maps resulted from early science observations in Spring 2008. MUSTANG+GBT 3mm map of Cas A

MUSTANG+GBT map of Cas A collected during commissioning, January 2009.

MUSTANG+GBT 3mm Map of the W3 region, 0.4 deg x 0.3 deg

MUSTANG+GBT large-area map of the W3 region (0.4 deg x 0.3 deg)