A MULTIPLICITY CENSUS OF INTERMEDIATE-MASS STARS IN SCORPIUS-CENTAURUS
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ (United States)
- Department of Physics, University of Montreal, Montreal, QC (Canada)
- Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON (Canada)
- European Southern Observatory, Santiago (Chile)
- Department of Astronomy, Stockholm University, Stockholm (Sweden)
Stellar multiplicity properties have been studied for the lowest and the highest stellar masses, but intermediate-mass stars from F-type to late A-type have received relatively little attention. Here, we report on a Gemini/NICI snapshot imaging survey of 138 such stars in the young Scorpius-Centaurus (Sco-Cen) region, for the purpose of studying multiplicity with sensitivity down to planetary masses at wide separations. In addition to two brown dwarfs and a companion straddling the hydrogen-burning limit which we reported previously, here we present 26 new stellar companions and determine a multiplicity fraction within 0.''1-5.''0 of 21% {+-} 4%. Depending on the adopted semimajor axis distribution, our results imply a total multiplicity in the range of {approx}60%-80%, which further supports the known trend of a smooth continuous increase in the multiplicity fraction as a function of primary stellar mass. A surprising feature in the sample is a distinct lack of nearly equal-mass binaries, for which we discuss possible reasons. The survey yielded no additional companions below or near the deuterium-burning limit, implying that their frequency at >200 AU separations is not quite as high as might be inferred from previous detections of such objects within the Sco-Cen region.
- OSTI ID:
- 22130940
- Journal Information:
- Astrophysical Journal, Vol. 773, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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