Artículos de revistas
Eridanus IV: an ultra-faint dwarf galaxy candidate discovered in the DECam local volume exploration survey
Fecha
2021Registro en:
The Astrophysical Journal Letters, 920:L44 (9pp), 2021 October 20
10.3847/2041-8213/ac2d9a
Autor
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.
Muñoz, 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.
Adamow, M.
Hernandez Lang, D.
Kuropatkin, N.
Santana Silva, L.
Tucker, D. L.
Zenteno, A.
Institución
Resumen
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 (epsilon = 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 tau similar to 13.0 Gyr and metallicity of [Fe/H] less than or similar to - 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 (mu(alpha) cos delta,mu(delta))=(+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.