GLEAM: The GaLactic and Extragalactic All-Sky MWA Survey

Wayth, R. B.; Lenc, E.; Bell, M. E.; Callingham, J. R.; Dwarakanath, K. S.; Franzen, T. M. O.; For, Bi-Qing; Gaensler, B. M.; Hancock, P. J.; Hindson, L.; Hurley‐Walker, N.; Jackson, C. A.; Johnston‐Hollitt, M.; Kapińska, A. D.; McKinley, B.; Morgan, John S.; Offringa, A. R.; Procopio, P.; Staveley‐Smith, L.; Wu, Chen; Zheng, Qian; Trott, Cathryn M.; Bernardi, G.; Bowman, Judd D.; Briggs, F.; Cappallo, R. J.; Corey, B. E.; Deshpande, A. A.; Emrich, D.; Goeke, R.; Greenhill, L. J.; Hazelton, B. J.; Kaplan, D. L.; Kasper, J. C.; Kratzenberg, E.; Lonsdale, Colin J.; Lynch, M. J.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Ord, S. M.; Prabu, T.; Rogers, A. E. E.; Roshi, A.; Shankar, N. Udaya; Srivani, K. S.; Subrahmanyan, R.; Tingay, S. J.; Waterson, M.; Webster, R. L.; Whitney, A. R.; Williams, Anne; Williams, C. L.

doi:10.1017/pasa.2015.26

Cited by 320 publications

(234 citation statements)

References 44 publications

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“…In this paper, we present a technique for identifying H ii regions using multi-band observations at low frequency. The resultant catalogue of H ii regions was compiled using the GaLactic Extragalactic All-sky MWA (GLEAM: Wayth et al 2015) survey between 72 and 231 MHz. The GLEAM observations allow us to probe new areas of parameter space as compared with existing Galactic plane surveys (see Figure 1).…”

Section: Hindson Et Almentioning

confidence: 99%

A Large-Scale, Low-Frequency Murchison Widefield Array Survey of Galactic H ii Regions between 260 < l < 340

Hindson

Johnston‐Hollitt

Hurley‐Walker

et al. 2016

Publ. Astron. Soc. Aust.

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We have compiled a catalogue of H ii regions detected with the Murchison Widefield Array between 72 and 231 MHz. The multiple frequency bands provided by the Murchison Widefield Array allow us identify the characteristic spectrum generated by the thermal Bremsstrahlung process in H ii regions. We detect 306 H ii regions between 260° < l < 340° and report on the positions, sizes, peak, integrated flux density, and spectral indices of these H ii regions. By identifying the point at which H ii regions transition from the optically thin to thick regime, we derive the physical properties including the electron density, ionised gas mass, and ionising photon flux, towards 61 H ii regions. This catalogue of H ii regions represents the most extensive and uniform low frequency survey of H ii regions in the Galaxy to date.

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Section: Hindson Et Almentioning

confidence: 99%

A Large-Scale, Low-Frequency Murchison Widefield Array Survey of Galactic H ii Regions between 260 < l < 340

Hindson

Johnston‐Hollitt

Hurley‐Walker

et al. 2016

Publ. Astron. Soc. Aust.

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“…This is followed by our polarisation and Rotation Measure (RM) studies of the SNR in Section 3.3. In Section 3.4, we present spectral index maps, and calculate a revised G1.9+0.3 spectral index using our ATCA observations and data from the GaLactic and Extragalactic All-sky MWA survey (GLEAM) project (Wayth et al 2015). In Section 3.5, we then calculate the general and local radio flux density increase of G1.9+0.3.…”

Section: Introductionmentioning

confidence: 99%

Radio observations of supernova remnant G1.9+0.3

Luken

Filipović

Maxted

et al. 2019

Monthly Notices of the Royal Astronomical Society

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We present 1 to 10 GHz radio continuum flux density, spectral index, polarisation and Rotation Measure (RM) images of the youngest known Galactic Supernova Remnant (SNR) G1.9+0.3, using observations from the Australia Telescope Compact Array (ATCA). We have conducted an expansion study spanning 8 epochs between 1984 and 2017, yielding results consistent with previous expansion studies of G1.9+0.3. We find a mean radio continuum expansion rate of (0.78±0.09) per cent year −1 (or ∼ 8900 km s −1 at an assumed distance of 8.5 kpc), although the expansion rate varies across the SNR perimeter. In the case of the most recent epoch between 2016 and 2017, we observe faster-than-expected expansion of the northern region. We find a global spectral index for G1.9+0.3 of −0.81 ± 0.02 (76 MHz-10 GHz). Towards the northern region, however, the radio spectrum is observed to steepen significantly (∼ −1). Towards the two so called (east & west) "ears" of G1.9+0.3, we find very different RM values of 400-600 rad m 2 and 100-200 rad m 2 respectively. The fractional polarisation of the radio continuum emission reaches (19 ± 2) per cent, consistent with other, slightly older, SNRs such as Cas A.

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“…We have endeavoured to detect the signature of dark matter annihilations in the form of extended synchrotron emission from Local Group dwarf spheroidal galaxies with use of the GLEAM survey (Wayth et al 2015). We extract 4 • × 4 • cutout images centred upon each dSph galaxy.…”

Section: Gleam Imagesmentioning

confidence: 99%

Searching for dark matter signals from local dwarf spheroidal galaxies at low radio frequencies in the GLEAM survey

Cook

Seymour

Spekkens

et al. 2020

Monthly Notices of the Royal Astronomical Society

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The search for emission from weakly interacting massive particle (WIMP) dark matter annihilation and decay has become a multi-pronged area of research not only targeting a diverse selection of astrophysical objects, but also taking advantage of the entire electromagnetic spectrum. The decay of WIMP particles into standard model particles has been suggested as a possible channel for synchrotron emission to be detected at low radio frequencies. Here, we present the stacking analysis of a sample of 33 dwarf spheroidal (dSph) galaxies with low-frequency (72 -231 MHz) radio images from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. We produce radial surface brightness profiles of images centred upon each dSph galaxy with background radio sources masked. We remove ten fields from the stacking due to contamination from either poorly subtracted, bright radio sources or strong background gradients across the field. The remaining 23 dSph galaxies are stacked in an attempt to obtain a statistical detection of any WIMP-induced synchrotron emission in these systems. We find that the stacked radial brightness profile does not exhibit a statistically significant detection above the 95% confidence level of ∼ 1.5 mJy beam −1 . This novel technique shows the potential of using low-frequency radio images to constrain fundamental properties of particle dark matter.

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GLEAM: The GaLactic and Extragalactic All-Sky MWA Survey

Cited by 320 publications

References 44 publications

A Large-Scale, Low-Frequency Murchison Widefield Array Survey of Galactic H ii Regions between 260 < l < 340

A Large-Scale, Low-Frequency Murchison Widefield Array Survey of Galactic H ii Regions between 260 < l < 340

Radio observations of supernova remnant G1.9+0.3

Searching for dark matter signals from local dwarf spheroidal galaxies at low radio frequencies in the GLEAM survey

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