survey
Background image: 21-cm atomic hydrogen emission from the HI4PI survey
GASKAP-OH is one of the nine approved Survey Science Projects (SSPs) to be carried out on the Australia Square Kilometre Array Pathfinder (ASKAP) telescope.
ASKAP consists of 36 dish antennas, 12m in diameter, situated in one of the most radio-quiet locations in the world – Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory.
Its Phased Array Feed (PAF) receivers allow it to observe a field of view of approximately 25 square degrees in a single pointing, and its backend permits a velocity resolution of up to ∼ 0.1 km s−1 (at the frequency of the OH lines) in a single 9 MHz band (see Hotan et al. 2021, for detailed system information).
Survey Specifications
The above figure shows the GASKAP-OH survey region, and the following table shows the expected sensitivity and resolution in each of the survey subregions. The Galactic Centre, Galactic Bulge and LMC will be observed in multiple epochs to quantify maser variability and derive a more complete population of sources. In common with all ASKAP SSPs, GASKAP-OH data will be processed automatically by the observatory using the ASKAPsoft package, and released to the survey-team as a collection of datacubes, images and catalogues.
| Region | TIme/field (hrs) | No. fields | Epochs | Lines | Total time (hrs) | Target rms (mJy/beam) | Vel chan (km/s) | HPBW (arcsec) |
| Galactic Plane | 6 | 18 | 1 | All | 342 | 36 (15) | 0.1 (0.7) | 10 |
| Galactic Centre | 18 | 1 | 6 | All | 56 | 18 (7) | 0.1 (0.7) | 10 |
| Galactic Bulge | 6 | 13 | 3 | 1612 MHz | 78 | 8 | 0.2 | 10 |
| LMC | 50 | 1 | 4 | 1612 MHz | 50 | 36 (15) | 0.1 (0.7) | 10 |