Is there really a debris disc around ζ2 Reticuli?. Issue 1 (25th August 2018)

• Record Type: Journal Article
• Authors: Faramaz, V; Bryden, G; Stapelfeldt, K R; Booth, M; Bayo, A; Beust, H; Casassus, S; Cuadra, J; Hales, A; Hughes, A M; Olofsson, J; Su, K Y L; Wilner, D J
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 481:Issue 1(2018)
• Page Start: 44
• Page End: 48
• Publication Date: 2018-08-25
• Subjects: Circumstellar matter -- Stars: individual: ζ2 Reticuli; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty2304
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: The presence of a debris disc around the Gyr-old solar-type star $\zeta ^2\, \mathrm{Reticuli}\, $ was suggested by the Spitzer infrared excess detection. Follow-up observations with Herschel /PACS revealed a double-lobed feature that displayed asymmetries both in brightness and position. Therefore, the disc was thought to be edge-on and significantly eccentric. Here we present ALMA/ACA observations in Band 6 and 7 which unambiguously reveal that these lobes show no common proper motion with $\zeta ^2\, \mathrm{Reticuli}\, $ . In these observations, no flux has been detected around $\zeta ^2\, \mathrm{Reticuli}\, $ that exceeds the 3σ levels. We conclude that surface brightness upper limits of a debris disc around $\zeta ^2\, \mathrm{Reticuli}\, $ are $5.7\, \mathrm{\mu Jy\, arcsec^{-2}}$ at 1.3 mm, and $26\, \mathrm{\mu Jy\, arcsec^{-2}}$ at 870 microns. Our results overall demonstrate the capability of the ALMA/ACA to follow-up Herschel observations of debris discs and clarify the effects of background confusion.