A new analysis of the MEGA M31 microlensing events
arXiv:astro-ph/0610239 · doi:10.1051/0004-6361:20065851
Abstract
We discuss the results of the MEGA microlensing campaign towards M31. Our analysis is based on an analytical evaluation of the microlensing rate, taking into account the observational efficiency as given by the MEGA collaboration. In particular, we study the spatial and time duration distributions of the microlensing events for several mass distribution models of the M31 bulge. We find that only for extreme models of the M31 luminous components it is possible to reconcile the total observed MEGA events with the expected self-lensing contribution. Nevertheless, the expected spatial distribution of self-lensing events is more concentrated and hardly in agreement with the observed distribution. We find it thus difficult to explain all events as being due to self-lensing alone. On the other hand, the small number of events does not yet allow to draw firm conclusions on the halo dark matter fraction in form of MACHOs.
in press on A&A
References in corpus (28)
- The MACHO Project: Microlensing Results from 5.7 Years of LMC Observations
- Possible Gravitational Microlensing of a Star in the Large Magellanic Cloud
- HST STIS spectroscopy of the triple nucleus of M31: two nested disks in Keplerian rotation around a Supermassive Black Hole
- Equilibrium Disk-Bulge-Halo Models for the Milky Way and Andromeda Galaxies
- M Dwarfs From Hubble Space Telescope Star Counts III: The Groth Strip
- The Initial Mass Function of the Galactic Bulge Down to ~0.15 Msun
- Extended HI Rotation Curve and Mass Distribution of M31
- Theory of Pixel Lensing
- POINT-AGAPE Pixel Lensing Survey of M31 : Evidence for a MACHO contribution to Galactic Halos
- Results from a Survey of Gravitational Microlensing towards M31
- A Short Timescale Candidate Microlensing Event in the POINT-AGAPE Pixel Lensing Survey of M31
- The Point-Agape survey: 4 high signal-to-noise ratio microlensing candidates detected towards M31
- The Anomaly in the Candidate Microlensing Event PA-99-N2
- Theory of pixel lensing towards M31 I: the density contribution and mass of MACHOs
- The Wendelstein Calar Alto Pixellensing Project(WeCAPP): First MACHO Candidates
- First Microlensing Events From The MEGA Survey Of M31
- Microlensing search towards M31
- MACHOs in M31? Absence of evidence but not evidence of absence
- The Angstrom Project: a microlensing survey of the structure and composition of the bulge of the Andromeda galaxy
- Microlensing towards the Large Magellanic Cloud
- The impact of spheroid stars for Macho microlensing surveys of the Andromeda Galaxy
- Microlensing toward crowded fields: Theory and applications to M31
- Microlensing towards M31 with MDM data
- Monte Carlo analysis of the MEGA microlensing events towards M31
- First microlensing candidate towards M31 from the Nainital Microlensing Survey
- Event rates and timescale distributions from realistic microlensing models of M31
- Influence of magnification threshold on pixel lensing optical depth, event rate and time scale distributions towards M31
- Theory of pixel lensing towards M31 -- II. The velocity anisotropy and flattening of the MACHO distribution
Cited by in corpus (19)
- Pixel-lensing as a way to detect extrasolar planets in M31
- Antimatter and antistars in the universe and in the Galaxy
- Microlensing Searches for Exoplanets
- Massive and supermassive black holes in the contemporary and early universe and the new problems of cosmology and astrophysics
- PAndromeda - first results from the high-cadence monitoring of M31 with Pan-STARRS 1
- M31 pixel lensing event OAB-N2: a study of the lens proper motion
- Pixel lensing: Microlensing towards M31
- Notes on Hidden Mirror World
- Search for exoplanets in M31 with pixel-lensing and the PA-99-N2 event revisited
- Probing MACHOs by observation of M31 pixel lensing with the 1.5m Loiano telescope
- Measuring Polarization in microlensing events
- Unlocking the secrets of stellar haloes using combined star counts and surface photometry
- CMB as a possible new tool to study the dark baryons in galaxies
- M31 Pixel Lensing PLAN Campaign: MACHO Lensing and Self Lensing Signals
- Beasts in Lambda-CDM Zoo
- The POINT-AGAPE Survey: Comparing Automated Searches of Microlensing Events toward M31
- Massive Primordial Black Holes
- Microlensing towards the Magellanic Clouds and M31: is the quest for MACHOs still open?
- Gravitational microlensing constraints on primordial black holes by Euclid