TY - JOUR
T1 - The discovery of X-ray binaries in the Sculptor dwarf spheroidal galaxy
AU - Maccarone, Thomas J.
AU - Kundu, Arunav
AU - Zepf, Stephen E.
AU - Piro, Anthony L.
AU - Bildsten, Lars
PY - 2005/11
Y1 - 2005/11
N2 - We report the results of a deep Chandra survey of the Sculptor dwarf spheroidal galaxy. We find five X-ray sources with LX of at least 6 × 1033 erg s-1 with optical counterparts establishing them as members of Sculptor. These X-ray luminosities indicate that these sources are X-ray binaries, as no other known class of Galactic point sources can reach 0.5-8 keV luminosities this high. Finding these systems proves definitively that such objects can exist in an old stellar population without stellar collisions. Three of these objects have highly evolved optical counterparts (giants or horizontal branch stars), as do three other sources whose X-ray luminosities are in the range which includes both quiescent low-mass X-ray binaries and the brightest magnetic cataclysmic variables. We predict that large area surveys of the Milky Way should also turn up large numbers of quiescent X-ray binaries.
AB - We report the results of a deep Chandra survey of the Sculptor dwarf spheroidal galaxy. We find five X-ray sources with LX of at least 6 × 1033 erg s-1 with optical counterparts establishing them as members of Sculptor. These X-ray luminosities indicate that these sources are X-ray binaries, as no other known class of Galactic point sources can reach 0.5-8 keV luminosities this high. Finding these systems proves definitively that such objects can exist in an old stellar population without stellar collisions. Three of these objects have highly evolved optical counterparts (giants or horizontal branch stars), as do three other sources whose X-ray luminosities are in the range which includes both quiescent low-mass X-ray binaries and the brightest magnetic cataclysmic variables. We predict that large area surveys of the Milky Way should also turn up large numbers of quiescent X-ray binaries.
KW - Galaxies: individual: sculptor dwarf spheroidal
KW - Stars: binaries: close
KW - Stars: population II
KW - Stellar dynamics
KW - X-rays: binaries
KW - X-rays: galaxies
UR - http://www.scopus.com/inward/record.url?scp=34347267002&partnerID=8YFLogxK
U2 - 10.1111/j.1745-3933.2005.00106.x
DO - 10.1111/j.1745-3933.2005.00106.x
M3 - Letter
AN - SCOPUS:34347267002
SN - 1745-3933
VL - 364
SP - L61-L65
JO - Monthly Notices of the Royal Astronomical Society: Letters
JF - Monthly Notices of the Royal Astronomical Society: Letters
IS - 1
ER -