Chromaticity of Gravitational Microlensing Events
arXiv:astro-ph/9911375 · doi:10.1046/j.1365-8711.2000.03485.x
Abstract
In this paper, we investigate the color changes of gravitational microlensing events caused by the two different mechanisms of differential amplification for a limb-darkened extended source and blending. From this investigation, we find that the color changes of limb-darkened extended source events (color curves) have dramatically different characteristics depending on whether the lens transits the source star or not. We show that for a source transit event, the lens proper motion can be determined by simply measuring the turning time of the color curve instead of fitting the overall color or light curves. We also find that even for a very small fraction of blended light, the color changes induced by the blending effect is equivalent to those caused by the limb-darkening effect, causing serious distortion in the observed color curve. Therefore, to obtain useful information about the lens and source star from the color curve of a limb-darkened extended source event, it will be essential to eliminate or correct for the blending effect. We discuss about the methods for the efficient correction of the blending effect.
total 18 pages, including 5 figures and no table, MNRAS, submitted
References in corpus (16)
- A method for optimal image subtraction
- Possible Gravitational Microlensing of a Star in the Large Magellanic Cloud
- The MACHO Project LMC Microlensing Results from the First Two Years and the Nature of the Galactic Dark Halo
- Finite Source Sizes and the Information Content of MACHO-Type Lens Search Light Curves
- MACHO Alert 95-30 : First Real-Time Observation of Extended Source Effects in Gravitational Microlensing
- The 1995 Pilot Campaign of PLANET: Searching for Microlensing Anomalies through Precise, Rapid, Round-the-Clock Monitoring
- Astrometric Observation of MACHO Gravitational Microlensing
- Observations of the Binary Microlens Event MACHO-98-SMC-1 by the Microlensing Planet Search Collaboration
- Statistical Determination of the MACHO Mass Spectrum
- Macho Proper Motions From Optical/Infrared Photometry
- Difference Image Analysis of Galactic Microlensing I. Data Analysis
- Difference Image Analysis of Galactic Microlensing II. Microlensing Events
- Correction for Blending Problem in Gravitational Microlensing Events by Using Hubble Space Telescope
- An Additional Application of the Space Interferometry Mission to Gravitational Microlensing Experiments
- The Applicability of the Astrometric Method in Determining the Physical Parameters of Gravitational Microlenses
- Observational Evidence for the Effect of Amplification Bias in Gravitational Microlensing Experiments
Cited by in corpus (12)
- Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey II: Free-Floating Planet Detection Rates
- Gravitational lensing in eclipsing binary stars
- WeCAPP - The Wendelstein Calar Alto Pixellensing Project I Tracing Dark and Bright Matter in M31
- Chromaticity effects in microlensing by wormholes
- Microlensing toward crowded fields: Theory and applications to M31
- The microlensing signatures of starspots
- Search for exotic matter from gravitational microlensing observations of stars
- Gravitational lensing as a possible explanation for some unidentified gamma-ray sources at high latitudes
- Megachannel Extraterrestrial Assay Candidates: No Transmissions from Intrinsically Steady Sources
- On the possibility of an astronomical detection of chromaticity effects in microlensing by wormhole-like objects
- Colour Change Measurements of Gravitational Microlensing Events by Using the Difference Image Analysis Method
- Variation of the stellar color in high-magnification and caustic-crossing microlensing events