The LOTRUN survey will survey the Galactic radio sky at sub-second timescales. The survey comprises 20 fields spanning a total of 720 square degrees, ranging galactic longitudes -48° < l < 48°. Each field will be observed for 2 hours at a time, with 5 repeats spaced ~monthly, totalling 200h of observing time. Survey observations commence in September 2025.

Data will be recorded simultaneously with the standard ASKAP correlator (“continuum”; 10 second resolution) and the high time resolution CRACO backend (110 millisecond resolution). Continuum data products, including continuum images, mosaics, source catalogues, and visibilities, will be publicly available on CASDA. In addition, 110 ms resolution visibilities recorded by CRACO will be deposited on CASDA for full public access. All LOTRUN data will be deposited under Project ID AS116.

For questions regarding the survey, please contact the survey lead, Andrew Zic.

Survey parameters

Observing modeCRACOStandard correlator
Frequency887.5 MHz
Bandwidth288 MHz
Frequency resolution1 MHz
Integration time2 h
Time resolution110 ms10 s
PolarisationTotal-intensity
(Stokes I)		Full polarisation
(Stokes I, Q, U, V)
Sky coverage-48° < l < 48°; -9° < b < 8°
Fields20
Repeats5
Cadence~1-2 months
Footprintsquare_6x6
Beam spacing1.05°
Surveyed area720 sq. deg
LOTRUN survey parameters. Details are provided for data recorded both through the CRACO backend and through the standard ASKAP imaging correlator. Where details differ between these, relevant information is provided. Blank cells otherwise indicate values consistent with the CRACO column.

Sky coverage

The CSIRO-developed Phased Array Feed (PAF) technology provides ASKAP with a large field-of-view. The PAF forms 36 independent beam directions simultaneously in a “footprint”, which can be used to survey large areas of sky efficiently. The LOTRUN survey makes use of the ASKAP square_6x6 footprint, which provides a field of view of 36 square degrees.

ASKAP field-of-view showing positions for all 36 beams of a square_6x6 footprint.

Equirectangular projection of the Finkbeiner (2003) all-sky H-alpha composite map in Galactic coordinates, with the LOTRUN ASKAP footprints indicated with red circles.

A colour image of H-alpha intensity along the Galactic Plane, showing diffuse cloud-like structures. Overlaid are a series of mosaicked red circles, representing the ASKAP beam footprint for each of the 20 fields of the LOTRUN survey.

Equirectangular projection of the Finkbeiner (2003) all-sky H-alpha composite map in Galactic coordinates, with the LOTRUN ASKAP footprints indicated with red circles for each of the 20 fields. H-alpha intensity is log-scaled.

Equirectangular projection of the Gaia Early Data Release 3 all-sky colour image in Galactic coordinates, with the ASKAP footprints for the LOTRUN survey indicated with red circles.

A colour image of the Optical sky along the Galactic Plane, showing an abundance of stars and dust clouds. Overlaid are a series of mosaicked red circles, representing the ASKAP beam footprint for each of the 20 fields of the LOTRUN survey.

Equirectangular projection of the Gaia Early Data Release 3 all-sky colour image in Galactic coordinates, with the LOTRUN ASKAP footprints indicated with red circles for each of the 20 fields. Copyright: ESA/Gaia/DPAC; CC BY-SA 3.0 IGO. Acknowledgement: A. Moitinho.

The survey fields were chosen on the basis of access to low Galactic latitudes, where the stellar density is highest, while maximising the potential for discoveries at short timescales by avoiding regions where radio wave scattering is likely strongest. The field locations in equatorial and galactic coordinates are provided below.

Field nameEquatorial coordinatesGalactic coordinates
LTR_1913+104319:13:42.6 +10:43:25.345.0 +0.0
LTR_1902+052319:02:32.3 +05:23:54.239.0 +0.0
LTR_1851+000318:51:33.7 +00:03:38.133.0 +0.0
LTR_1840-051618:40:35.2 -05:16:38.527.0 +0.0
LTR_1840-115818:40:17.3 -11:58:57.721.0 -3.0
LTR_1818-091218:18:39.2 -09:12:01.421.0 +3.0
LTR_1840-184018:40:09.7 -18:40:25.215.0 -6.0
LTR_1759-132917:59:45.4 -13:29:14.515.0 +5.0
LTR_1828-235918:28:35.3 -23:59:54.09.0 -6.0
LTR_1747-183917:47:15.9 -18:39:26.79.0 +5.0
LTR_1812-284918:12:14.7 -28:49:28.53.0 -5.0
LTR_1733-234417:33:47.4 -23:44:37.43.0 +5.0
LTR_1758-340317:58:41.4 -34:03:25.9357.0 -5.0
LTR_1719-284317:19:01.2 -28:43:13.7357.0 +5.0
LTR_1610-485516:10:01.5 -48:55:26.8333.0 +2.0
LTR_1536-515715:36:56.3 -51:57:54.4327.0 +3.0
LTR_1602-563916:02:39.9 -56:39:13.7327.0 -3.0
LTR_1502-551115:02:52.7 -55:11:34.1321.0 +3.0
LTR_1441-631514:41:59.5 -63:15:05.4315.0 -3.0
LTR_1423-574214:23:26.2 -57:42:00.1315.0 +3.0