Statistical Determination of the MACHO Mass Spectrum

Abstract

view Abstract Citations (96) References (31) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Statistical Determination of the MACHO Mass Spectrum Han, Cheongho ; Gould, Andrew Abstract The mass function of 51 massive compact halo objects (MACHOs) detected toward the Galactic bulge is statistically estimated from Einstein ring crossing times tE. For a Gaussian mass function, the best-fit parameters are log m = -1.12 and σlog m = 0.57. If the mass function follows a power-law distribution, the best-fit mass cutoff and power are mcut = 0.04 Msun and p = -2.1. Both mass spectra indicate that a significant fraction of events are caused by MACHOs in the substellar mass range. Both best determined mass functions are compared with that obtained from Hubble Space Telescope (HST) observations. The power law is marginally favored (2.3 σ) over the Gaussian mass function and significantly favored over the HST mass function (5.5 σ), indicating that MACHOs have a different mass function from stars in the solar neighborhood. In addition, the fact that all the models have very poor fits to the longest four events, with tE ≥ 70 days, remains a puzzle. Publication: The Astrophysical Journal Pub Date: August 1996 DOI: 10.1086/177631 arXiv: arXiv:astro-ph/9504078 Bibcode: 1996ApJ...467..540H Keywords: COSMOLOGY: GRAVITATIONAL LENSING; COSMOLOGY: DARK MATTER; Astrophysics E-Print: 18 pages including 5 figures, revised full text sources arXiv | ADS |

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