The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) - art. no. 70101B

Conference item

Dark matter in a universe dominated by a cosmological constant seeds the formation of structure and is the scaffolding for galaxy formation. The nature of dark matter remains one of the fundamental unsolved problems in astrophysics and physics even though it represents 85% of the mass in the universe, and nearly one quarter of its total mass-energy budget. The mass function of dark matter "substructure" on sub-galactic scales may be enormously sensitive to the mass and properties of the dark matter particle. On astrophysical scales, especially at cosmological distances, dark matter substructure may only be detected through its gravitational influence on light from distant varying sources. Specifically, these are largely active galactic nuclei (AGN), which are accreting super-massive black holes in the centers of galaxies, some of the most extreme objects ever found. With enough measurements of the flux from AGN at different wavelengths, and their variability over time, the detailed structure around AGN, and even the mass of the super-massive black hole can be measured. The Observatory for Multi-Epoch Gravitational Lens Astrophysics (OMEGA) is a mission concept for a 1.5-m near-UV through near-IR space observatory that will be dedicated to frequent imaging and spectroscopic monitoring of-100 multiply-imaged active galactic nuclei over the whole sky. Using wavelength-tailored dichroics with extremely high transmittance, efficient imaging in six channels will be done simultaneously during each visit to each target. The separate spectroscopic mode, engaged through a flip-in mirror, uses an image slicer spectrograph. After a period of many visits to all targets, the resulting multidimensional movies can then be analyzed to a) measure the mass function of dark matter substructure; b) measure precise masses of the accreting black holes as well as the structure of their accretion disks and their environments over several decades of physical scale; and c) measure a combination of Hubble's local expansion constant and cosmological distances to unprecedented precision. We present the novel OMEGA instrumentation suite, and how its integrated design is ideal for opening the time domain of known cosmologically-distant variable sources, to achieve the stated scientific goals.

Authors: Moustakas, L; Bolton, A; Booth, J; Bullock, J; Cheng, E

• Publication status: Published
• Host title: SPACE TELESCOPES AND INSTRUMENTATION 2008: OPTICAL, INFRARED, AND MILLIMETER, PTS 1 AND 2
• Volume: 7010
• Pages: B101-B101
• Publication date: 2008-01-01
• DOI: 10.1117/12.789987
• ISSN: 0277-786X
• ISBN: 9780819472205
• Keywords: space telescope; spectroscopy; astronomical survey; time domain; dark matter; strong gravitational lensing; expansion history; active galactic nuclei