TY - JOUR
T1 - Magellanic System Stars Identified in SMACS J0723.3-7327 James Webb Space Telescope Early Release Observations Images
AU - Summers, Jake
AU - Windhorst, Rogier A.
AU - Cohen, Seth H.
AU - Jansen, Rolf A.
AU - Carleton, Timothy
AU - Kamieneski, Patrick S.
AU - Holwerda, Benne W.
AU - Conselice, Christopher J.
AU - Adams, Nathan J.
AU - Frye, Brenda L.
AU - Diego, Jose M.
AU - Willmer, Christopher N.A.
AU - Ortiz, Rafael
AU - Cheng, Cheng
AU - Pigarelli, Alex
AU - Robotham, Aaron
AU - D’Silva, Jordan C.J.
AU - Tompkins, Scott
AU - Driver, Simon P.
AU - Yan, Haojing
AU - Coe, Dan
AU - Grogin, Norman
AU - Koekemoer, Anton M.
AU - Marshall, Madeline A.
AU - Pirzkal, Nor
AU - Ryan, Russell E.
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/12/1
Y1 - 2023/12/1
N2 - We identify 71 distant stars in James Webb Space Telescope/NIRCam early release observations (ERO) images of the field of galaxy cluster SMACS J0723.3-7327 (SMACS 0723). Given the relatively small (∼10°) angular separation between SMACS 0723 and the Large Magellanic Cloud (LMC), it is likely that these stars are associated with the LMC outskirts or the Leading Arm. This is further bolstered by a spectral energy distribution (SED) analysis, which suggests an excess of stars at a physical distance of 40-100 kpc, consistent with being associated with or located behind the Magellanic system. In particular, we find that the overall surface density of stars brighter than 27.0 mag in the field of SMACS 0723 is ∼2.3 times that of stars in a blank field with similar Galactic latitude (the North Ecliptic Pole Time Domain Field), and that the density of stars in the SMACS 0723 field with SED-derived distances consistent with the Magellanic system is ∼6.1 times larger than that of the blank field. The candidate stars at these distances are consistent with a stellar population at the same distance modulus with [Fe/H] = −1.0 and an age of ∼5.0 Gyr. On the assumption that all of the 71 stars are associated with the LMC, then the stellar density of the LMC at the location of the SMACS 0723 field is ∼740 stars kpc−3, which helps trace the density of stars in the LMC outskirts.
AB - We identify 71 distant stars in James Webb Space Telescope/NIRCam early release observations (ERO) images of the field of galaxy cluster SMACS J0723.3-7327 (SMACS 0723). Given the relatively small (∼10°) angular separation between SMACS 0723 and the Large Magellanic Cloud (LMC), it is likely that these stars are associated with the LMC outskirts or the Leading Arm. This is further bolstered by a spectral energy distribution (SED) analysis, which suggests an excess of stars at a physical distance of 40-100 kpc, consistent with being associated with or located behind the Magellanic system. In particular, we find that the overall surface density of stars brighter than 27.0 mag in the field of SMACS 0723 is ∼2.3 times that of stars in a blank field with similar Galactic latitude (the North Ecliptic Pole Time Domain Field), and that the density of stars in the SMACS 0723 field with SED-derived distances consistent with the Magellanic system is ∼6.1 times larger than that of the blank field. The candidate stars at these distances are consistent with a stellar population at the same distance modulus with [Fe/H] = −1.0 and an age of ∼5.0 Gyr. On the assumption that all of the 71 stars are associated with the LMC, then the stellar density of the LMC at the location of the SMACS 0723 field is ∼740 stars kpc−3, which helps trace the density of stars in the LMC outskirts.
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U2 - 10.3847/1538-4357/acffb9
DO - 10.3847/1538-4357/acffb9
M3 - Article
AN - SCOPUS:85177497535
SN - 0004-637X
VL - 958
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 108
ER -