TY - JOUR
T1 - Lacerta i and cassiopeia III. Two luminous and distant andromeda satellite dwarf galaxies found in the 3π pan-starrs1 survey
AU - Martin, Nicolas F.
AU - Slater, Colin T.
AU - Schlafly, Edward F.
AU - Morganson, Eric
AU - Rix, Hans Walter
AU - Bell, Eric F.
AU - Laevens, Benjamin P.M.
AU - Bernard, Edouard J.
AU - Ferguson, Annette M.N.
AU - Finkbeiner, Douglas P.
AU - Burgett, William S.
AU - Chambers, Kenneth C.
AU - Hodapp, Klaus W.
AU - Kaiser, Nicholas
AU - Kudritzki, Rolf Peter
AU - Magnier, Eugene A.
AU - Morgan, Jeffrey S.
AU - Price, Paul A.
AU - Tonry, John L.
AU - Wainscoat, Richard J.
PY - 2013/7/20
Y1 - 2013/7/20
N2 - We report the discovery of two new dwarf galaxies, Lacerta I/Andromeda XXXI (Lac I/And XXXI) and Cassiopeia III/Andromeda XXXII (Cas III/And XXXII), in stacked Pan-STARRS1 r P1- and i P1-band imaging data. Both are luminous systems (MV -12) located at projected distances of 20.°3 and 10.°5 from M31. Lac I and Cas III are likely satellites of the Andromeda galaxy with heliocentric distances of and , respectively, and corresponding M31-centric distances of 275 ± 7 kpc and . The brightest of recent Local Group member discoveries, these two new dwarf galaxies owe their late discovery to their large sizes ( arcmin or for Lac I; arcmin or 1456 ± 267 pc for Cas III) and consequently low surface brightness (μ0 26.0 mag arcsec-2), as well as to the lack of a systematic survey of regions at large radii from M31, close to the Galactic plane. This latter limitation is now alleviated by the 3π Pan-STARRS1 survey, which could lead to the discovery of other distant Andromeda satellite dwarf galaxies.
AB - We report the discovery of two new dwarf galaxies, Lacerta I/Andromeda XXXI (Lac I/And XXXI) and Cassiopeia III/Andromeda XXXII (Cas III/And XXXII), in stacked Pan-STARRS1 r P1- and i P1-band imaging data. Both are luminous systems (MV -12) located at projected distances of 20.°3 and 10.°5 from M31. Lac I and Cas III are likely satellites of the Andromeda galaxy with heliocentric distances of and , respectively, and corresponding M31-centric distances of 275 ± 7 kpc and . The brightest of recent Local Group member discoveries, these two new dwarf galaxies owe their late discovery to their large sizes ( arcmin or for Lac I; arcmin or 1456 ± 267 pc for Cas III) and consequently low surface brightness (μ0 26.0 mag arcsec-2), as well as to the lack of a systematic survey of regions at large radii from M31, close to the Galactic plane. This latter limitation is now alleviated by the 3π Pan-STARRS1 survey, which could lead to the discovery of other distant Andromeda satellite dwarf galaxies.
KW - Local Group
KW - galaxies: individual (Andromeda XXXI, Andromeda XXXII, Cassiopeia III, Lacerta I)
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U2 - 10.1088/0004-637X/772/1/15
DO - 10.1088/0004-637X/772/1/15
M3 - Article
AN - SCOPUS:84879971295
SN - 0004-637X
VL - 772
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 15
ER -