English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present ALMA Band 6 observations (1.3 mm/233 GHz) of Fomalhaut and itsdebris disc. The observations achieve a sensitivity of 17 $\mu$Jy and aresolution of 0.28 arcsec (2.1 au at a distance of 7.66 pc), which are thehighest resolution observations to date of the millimetre grains in Fomalhaut'smain debris ring. The ring is tightly constrained to $139^{+2}_{-3}$ au with aFWHM of $13\pm3$ au, following a Gaussian profile. The millimetre spectralindex is constrained to $\alpha_{mm} = -2.62\pm0.12$. We explore fitting debrisdisc models in the image plane, as well as fitting models using visibility datadirectly. The results are compared and the potential advantages/disadvantagesof each approach are discussed.  The detected central emission is indistinguishable from a point source, witha most probable flux of $0.90\pm 0.12$ mJy (including calibrationuncertainties). This implies that any inner debris structure, as was inferredfrom far-Infrared observations, must contribute little to the total centralemission. Moreover, the stellar flux is less than 70\% of that predicted byextrapolating a black body from the constrained stellar photospheretemperature. This result emphasizes that unresolved inner debris componentscannot be fully characterized until the behaviour of the host star's intrinsicstellar emission at millimetre wavelengths is properly understood.

1.3 mm ALMA Observations of the Fomalhaut Debris System