Is Galactic Structure Compatible with Microlensing Data?
- 10 July 2000
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 537 (2) , L99-L102
- https://doi.org/10.1086/312767
Abstract
We generalize to elliptical models the argument of Kuijken (1997), which connects the microlensing optical depth towards the Galactic bulge to the Galactic rotation curve. When applied to the latest value from the MACHO collaboration for the optical depth for microlensing of bulge sources, the argument implies that the Galactic bar cannot plausibly reconcile the measured values of the optical depth, the rotation curve and the local mass density. Either there is a problem with the interpretation of the microlensing data, or our line of sight to the Galactic centre is highly atypical in that it passes through a massive structure that wraps only a small distance around the Galactic centre.Comment: Submitted to ApJ Letters. 8 pages LaTeX, 3 figures. Corrected error in description of microlensing observationKeywords
All Related Versions
This publication has 11 references indexed in Scilit:
- A dynamical model of the inner GalaxyMonthly Notices of the Royal Astronomical Society, 2000
- The local density of matter mapped by HipparcosMonthly Notices of the Royal Astronomical Society, 2000
- Gas dynamics and large-scale morphology of the Milky Way galaxyMonthly Notices of the Royal Astronomical Society, 1999
- ACOBEModel of the Galactic Bar and DiskThe Astrophysical Journal, 1998
- The Maximum Optical Depth toward Bulge Stars from Axisymmetric Models of the Milky WayThe Astrophysical Journal, 1997
- The microlensing optical depth of the COBEbulgeMonthly Notices of the Royal Astronomical Society, 1997
- The photometric structure of the inner GalaxyMonthly Notices of the Royal Astronomical Society, 1997
- The MACHO Project: 45 Candidate Microlensing Events from the First Year Galactic Bulge DataThe Astrophysical Journal, 1997
- Understanding the kinematics of Galactic Centre gasMonthly Notices of the Royal Astronomical Society, 1991
- The galactic disk surface mass density and the Galactic force K(z) at Z = 1.1 kiloparsecsThe Astrophysical Journal, 1991