GASKAP The Galactic ASKAP Survey On behalf of the GASKAP team Dr Andrew Walsh

ASKAP – the Australian SKA Pathfinder 36 x 12m antennas Frequency range from 700 – 1800 MHz 30 square degree field of view Maximum baseline ~6km GASKAP1

ASKAP – the Australian SKA Pathfinder First 5 years, about 75% of time for Survey Science Projects (each at least 1500 hours) GASKAP2 Evolutionary Map of the Universe (EMU) Widefield ASKAP L-Band Legacy All-Sky Blind Survey (WALLABY) The First Large Absorption Survey in HI (FLASH) An ASKAP Survey for Variables and Slow Transients (VAST) Polarization Sky Survey of the Universe's Magnetism (POSSUM) The Commensal Real-time ASKAP Fast Transients survey (CRAFT) Deep Investigations of Neutral Gas Origins (DINGO) The High Resolution Components of ASKAP (VLBI) Compact Objects with ASKAP: Surveys and Timing (COAST) GASKAP –The Galactic ASKAP Survey

GASKAP – The Galactic ASKAP Survey GASKAP3 H I emission at 1420 MHz OH emission 1612, 1665 and 1667 MHz Galactic Plane: |b|<10°, 167° < l < 360° and 0° < l < 79° (all declinations south of δ=+40°) Entire area of Magellanic Stream and Clouds Sensitivity typically 1K at 30” resolution and 1 km/s

GASKAP – The Galactic ASKAP Survey GASKAP4 H I emission at 1420 MHz OH emission 1612, 1665 and 1667 MHz Galactic Plane: |b|<10°, 167° < l < 360° and 0° < l < 79° (all declinations south of δ=+40°) Entire area of Magellanic Stream and Clouds Sensitivity typically 1K at 30” resolution and 1 km/s

GASKAP – The Galactic ASKAP Survey GASKAP5 H I emission at 1420 MHz OH emission 1612, 1665 and 1667 MHz Galactic Plane: |b|<10°, 167° < l < 360° and 0° < l < 79° (all declinations south of δ=+40°) Entire area of Magellanic Stream and Clouds Sensitivity typically 1K at 30” resolution and 1 km/s

Maser science with GASKAP GASKAP6 Evolved stars Star formation Galactic kinematics/structure Magnetic fields Variability Milky Way – Magellanic Clouds comparison

Maser science with GASKAP GASKAP7 Evolved stars Flux limited survey of evolved stars in the Milky Way Expect to detect thousands of OH masers Identify rare masers associated very young (<100yr) planetary nebulae

Maser science with GASKAP GASKAP8 Star formation Flux limited survey of star formation masers in the Milky Way Expect to detect ~10 3 OH masers Maser timelines Star formation structure – disks/outflows ×10 4 3×10 4 4×10 4 5×10 4 Time (years) UCH II Class II CH 3 OH maser Class I CH 3 OH maser OH maser H 2 O maser Breen et al. (2010) maser timeline:

Maser science with GASKAP GASKAP9 Galactic Structure/Kinematics Both evolved star and star formation masers used to trace structure and kinematics of the Milky Way and MCs Star formation masers will be tightly linked to spiral arms – compare with Class II methanol masers from MMB Structure of the Galactic Centre (courtesy John Bally) Galactic Centre Structure (Artist’s impression byJohn Bally – private communication)

Maser science with GASKAP GASKAP10 Magnetic Fields OH, as paramagnetic molecule, is ideal polarisation tool Demonstrates Zeeman splitting (large splitting factor, milliGauss fields) Can be used to measure magnetic fields: larger scale with star forming OH masers small, local fields with evolved star masers Sensitivity to probe polarisation of weak maser features

Maser science with GASKAP GASKAP11 Variability OH masers are typically slowly varying over years GASKAP will involve multi-epoch observations of bright masers over 5 years Closely track variability in a large number of masers over these timescales

Maser science with GASKAP GASKAP12 Milky Way – Magellanic Clouds comparison GASKAP MC observations will increase number of known masers by two orders of magnitude Compare the occurrence of OH masers under normal- (Galactic) and low-metallicity (MCs) circumstances

Summary GASKAP13 GASKAP will be coming in a few years Observe the Galactic Plane, MCs and Magellanic Stream Includes 1612, 1665 and 1667 MHz OH transitions Discover thousands of new masers Learn about: Evolved stars, Star formation, Galactic kinematics/structure, Magnetic fields, OH maser Variability, Milky Way – MCs comparison