A Large Scale, Low Frequency Murchison Widefield Array Survey of Galactic HII regions between 260< l <\340

Abstract

We have compiled a catalogue of HII regions detected with the Murchison Widefield Array (MWA) between 72 and 231MHz. The multiple frequency bands provided by the MWA allow us identify the characteristic spectrum generated by the thermal Bremsstrahlung process in HII regions. We detect 302 HII regions between 260 < l < 340 and report on the positions, sizes, peak, integrated flux density, and spectral indices of these HII regions. By identifying the point at which HII 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 HII regions. This catalogue of HII regions represents the most extensive and uniform low frequency survey of HII regions in the Galaxy to date.

20 pages, 9 figures, 3 tables

References in corpus (8)

• The Very Large Array Low-frequency Sky Survey Redux (VLSSr)
• The Molonglo Galactic Plane Survey (MGPS-2): Compact Source Catalogue
• The low-frequency environment of the Murchison Widefield Array: radio-frequency interference analysis and mitigation
• The Southern Galactic Plane Survey: Polarized Radio Continuum Observations and Analysis
• The Murchison Widefield Array Commissioning Survey: A Low-Frequency Catalogue of 14,110 Compact Radio Sources over 6,100 Square Degrees
• The Density and Mass of Unshocked Ejecta in Cassiopeia A through Low Frequency Radio Absorption
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