Is the LMC Microlensing Due to an Intervening Dwarf Galaxy?

The MACHO Collaboration; C. Alcock; R. A. Allsman; D. R. Alves; T. S. Axelrod; A. Becker; D. P. Bennett; K. H. Cook; K. C. Freeman; K. Griest; M. J. Lehner; S. L. Marshall; D. Minniti; B. A. Peterson; M. R. Pratt; P. J. Quinn; A. W. Rodgers; A. Rorabeck; C. W. Stubbs; W. Sutherland; A. Tomaney; T. Vandehei; D. L. Welch

doi:10.1086/311016

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arXiv · astro-ph/9707310

Is the LMC Microlensing Due to an Intervening Dwarf Galaxy?

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Abstract

The recent suggestion that the microlensing events observed towards the Large Magellanic Cloud are due to an intervening Sgr-like dwarf galaxy is examined. A search for foreground RR Lyrae in the MACHO photometry database yields 20 stars whose distance distribution follow the expected halo density profile. Cepheid and red giant branch clump stars in the MACHO database are consistent with membership in the LMC. There is also no evidence in the literature for a distinct kinematic population, for intervening gas, or for the turn-off of such a hypothetical galaxy. We conclude that if the lenses are in a foreground galaxy, it must be a particularly dark galaxy.

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The MACHO Collaboration, C. Alcock, R. A. Allsman, D. R. Alves, T. S. Axelrod, A. Becker, D. P. Bennett, K. H. Cook, K. C. Freeman, K. Griest, M. J. Lehner, S. L. Marshall, D. Minniti, B. A. Peterson, M. R. Pratt, P. J. Quinn, A. W. Rodgers, A. Rorabeck, C. W. Stubbs, W. Sutherland, A. Tomaney, T. Vandehei, D. L. Welch. 1997-07-28. Is the LMC Microlensing Due to an Intervening Dwarf Galaxy?. https://doi.org/10.1086/311016

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