Perseus I: a distant satellite dwarf galaxy of Andromeda

Martin, N.F.; Schlafly, E.F.; Slater, C.T.; Bernard, E.J.; Rix, H.-W.; Bell, E.F.; Ferguson, A.M.N.; Finkbeiner, D.P.; Laevens, B.P.M.; Burgett, W.S.; Chambers, K.C.; Draper, P.W.; Hodapp, K.W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E.A.; Metcalfe, N.; Morgan, J.S.; Price, P.A.; Tonry, J.L.; Wainscoat, R.J.; Waters, C.

Abstract

We present the discovery of a new dwarf galaxy, Perseus I/Andromeda XXXIII, found in the vicinity of Andromeda (M31) in stacked imaging data from the Pan-STARRS1 3π survey. Located 27fdg9 away from M31, Perseus I has a heliocentric distance of 785 ± 65 kpc, compatible with it being a satellite of M31 at $374^{+14}_{-10}{\rm \,kpc}$ from its host. The properties of Perseus I are typical for a reasonably bright dwarf galaxy (MV = –10.3 ± 0.7), with an exponential half-light radius of rh = 1.7 ± 0.4 arcmin or $r_h = 400^{+105}_{-85}{\rm \,pc}$ at this distance, and a moderate ellipticity ($\epsilon = 0.43^{+0.15}_{-0.17}$). The late discovery of Perseus I is due to its fairly low surface brightness ($\mu _0=25.7^{+1.0}_{-0.9}$ mag arcsec–2), and to the previous lack of deep, high quality photometric data in this region. If confirmed to be a companion of M31, the location of Perseus I, far east from its host, could place interesting constraints on the bulk motion of the satellite system of M31.

Citation

Martin, N., Schlafly, E., Slater, C., Bernard, E., Rix, H., Bell, E., …Waters, C. (2013). Perseus I: a distant satellite dwarf galaxy of Andromeda. Astrophysical Journal Letters, 779(1), Article L10. https://doi.org/10.1088/2041-8205/779/1/l10

• Journal Article Type: Article
• Publication Date: Dec 10, 2013
• Deposit Date: Apr 3, 2014
• Publicly Available Date: Jun 30, 2014
• Journal: Astrophysical Journal Letters
• Print ISSN: 2041-8205
• Electronic ISSN: 2041-8213
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 779
• Issue: 1
• Article Number: L10
• DOI: https://doi.org/10.1088/2041-8205/779/1/l10
• Keywords: Galaxies: individual (Perseus I, Andromeda XXXIII), Local Group.