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Bulge Microlensing Optical Depth from EROS 2 observations
- Source :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2003, 404, pp.145-156. ⟨10.1051/0004-6361:20030307⟩, Astronomy and Astrophysics-A&A, 2003, 404, pp.145-156. ⟨10.1051/0004-6361:20030307⟩, Astronomy and Astrophysics-A&A, EDP Sciences, 2003, 404, pp.145
- Publication Year :
- 2003
-
Abstract
- We present a measurement of the microlensing optical depth toward the Galactic bulge based on the analysis of 15 contiguous1 square degrees fields centered on (l=2.5 deg, b=-4.0 deg) and containing 1.42 million clump-giant stars (belonging to the extended clump area) monitored during almost three bulge seasons by EROS (Experience de Recherche d'Objets Sombres). We find a microlensing optical depth towards the bulge tau_bulge=0.94 +/- 0.29 10^-6 averaged over all fields, based on 16 microlensing events with clump giants as sources. This value is substantially below several other determinations by the MACHO and OGLE groups and is more in agreement with what is expected from axisymmetric and non-axisymmetric bulge models.<br />18 pages, 15 images, accepted for publication in A&A
- Subjects :
- [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]
Astrophysics (astro-ph)
FOS: Physical sciences
Astrophysics::Solar and Stellar Astrophysics
Astrophysics::Earth and Planetary Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Astrophysics::Galaxy Astrophysics
Subjects
Details
- Language :
- English
- ISSN :
- 00046361
- Database :
- OpenAIRE
- Journal :
- Astronomy and Astrophysics-A&A, Astronomy and Astrophysics-A&A, EDP Sciences, 2003, 404, pp.145-156. ⟨10.1051/0004-6361:20030307⟩, Astronomy and Astrophysics-A&A, 2003, 404, pp.145-156. ⟨10.1051/0004-6361:20030307⟩, Astronomy and Astrophysics-A&A, EDP Sciences, 2003, 404, pp.145
- Accession number :
- edsair.doi.dedup.....ed6c18e33add13e035954e129a9d186f