2016/02/24 by A. Rowlinson, M. E. Bell, Tara Murphy +40
Physics and Astronomy · #Astronomy #Astrophysics #Dispersion (optics) #Fast radio burst #Flux (metallurgy) #Galaxy #Gamma-ray bursts and supernovae #Intergalactic travel #Interstellar medium #Limiting #Limiting magnitude #Optics #Physics #Population #Pulsars and Gravitational Waves Research #Radio Astronomy Observations and Technology #Redshift #Sky #Transient (computer programming) #astro-ph.HE #astro-ph.IM
paper · pdf · doi:10.1093/mnras/stw451
MNRAS Accepted, 17 pages, 10 figures
arxiv created 2016/02/24 · openalex publication_date 2016/03/01 · arxiv updated 2016/03/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a survey for transient and variable sources, on time-scales from 28 s to ∼1 yr, using the Murchison Widefield Array (MWA) at 182 MHz. Down to a detection threshold of 0.285 Jy, no transient candidates were identified, making this the most constraining low-frequency survey to date and placing a limit on the surface density of transients of <4.1 × 10−7 deg−2 for the shortest time-scale considered. At these frequencies, emission from Fast Radio Bursts (FRBs) is expected to be detectable in the shortest time-scale images without any corrections for interstellar or intergalactic dispersion. At an FRB limiting flux density of 7980 Jy, we find a rate of <82 FRBs per sky per day for dispersion measures <700 pc cm−3. Assuming a cosmological population of standard candles, our rate limits are consistent with the FRB rates obtained by Thornton et al. if they have a flat spectral slope. Finally, we conduct an initial variability survey of sources in the field with flux densities ≳0.5 Jy and identify no sources with significant variability in their light curves. However, we note that substantial further work is required to fully characterize both the short-term and low-level variability within this field.