Details

Autor(en) / Beteiligte

• Cerny, W.
• Pace, A. B.
• Drlica-Wagner, A.
• Koposov, S. E.
• Vivas, A. K.
• Mau, S.
• Riley, A. H.
• Bom, C. R.
• Carlin, J. L.
• Choi, Y.
• Erkal, D.
• Ferguson, P. S.
• James, D. J.
• Li, T. S.
• Martínez-Delgado, D.
• Martínez-Vázquez, C. E.
• Munoz, R. R.
• Mutlu-Pakdil, B.
• Olsen, K. A. G.
• Pieres, A.
• Sakowska, J. D.
• Sand, D. J.
• Simon, J. D.
• Smercina, A.
• Stringfellow, G. S.
• Tollerud, E. J.
• Adamów, M.
• Hernandez-Lang, D.
• Kuropatkin, N.
• Santana-Silva, L.
• Tucker, D. L.
• Zenteno, A.

Titel

Eridanus IV: an Ultra-faint Dwarf Galaxy Candidate Discovered in the DECam Local Volume Exploration Survey

Ist Teil von

• Astrophysical journal. Letters, 2021-10, Vol.920 (2), p.L44

Ort / Verlag

Austin: The American Astronomical Society

Erscheinungsjahr

2021

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Abstract We present the discovery of a candidate ultra-faint Milky-Way satellite, Eridanus IV (DELVE J0505−0931), detected in photometric data from the DECam Local Volume Exploration survey (DELVE). Eridanus IV is a faint ( M V = − 4.7 ± 0.2), extended ( r 1 / 2 = 75 − 13 + 16 pc ), and elliptical ( ϵ = 0.54 ± 0.1) system at a heliocentric distance of 76.7 − 6.1 + 4.0 kpc , with a stellar population that is well described by an old, metal-poor isochrone (age of τ ∼ 13.0 Gyr and metallicity of [Fe/H] ≲ − 2.1 dex). These properties are consistent with the known population of ultra-faint Milky-Way satellite galaxies. Eridanus IV is also prominently detected using proper-motion measurements from Gaia Early Data Release 3, with a systemic proper motion of ( μ α cos δ , μ δ ) = ( + 0.25 ± 0.06 , − 0.10 ± 0.05 ) mas yr −1 measured from its horizontal branch and red-giant-branch member stars. We find that the spatial distribution of likely member stars hints at the possibility that the system is undergoing tidal disruption.