1. Image of M8, taken by the AEOS Burst Camera 1 Heather Swan Physics Department University of Michigan Carl Akerlof, Timothy McKay, Eli Rykoff, Donald Smith, U of Michigan Mark Skinner, Andrew Alday, Kevin Moore, Boeing LTS

2. Outline Why? What is the AEOS and ABC? GRB response Data and simulations

3. GRB 030418 was dimmer than expected at early times Optical lightcurve First image ~76s after  -rays Circum-burst absorbs optical light if we could see the spectrum, we would expect to see red -> blue

4. GRB 990123 was brighter than expected at early times  -rays were still emitting for first few images Optical lightcurve Relativistic fireball – example of a reverse shock if we could see the spectrum, we would expect to see blue -> red

5. Swift’s BAT error box is the perfect size for the ABC 90% will be localized to a 3 arc minute radius (Can see them with the ABC) 50% will be localized within 12 seconds (Can see them promptly) (From Fenimore, et al)

6. The AEOS telescope is a large optical telescope used by the Air Force Advanced Electro-Optical Systems Telescope (AEOS) Largest ground based AF optical telescope (3.67m) Designed to track satellites, can quickly (~20 sec) slew to coordinates Located in Haleakala, Hawaii, at 10,000 ft ABC 6

7. The AEOS Burst Camera (ABC) is attached to the AEOS Optics designed by Carl Akerlof Package designed by Alan Schier Camera built by Astronomical Research Cameras Field of view 6' x 6' Focal length of 15.5m 9 ToO observations / year Limiting Mag ~22 nd for 10 sec exposure

8. Burst Filter Fax ::::::: GCN Swift GRB User Interface ABC Computers (Modified ROTSE Software) CD The ABC will try to observe GRBs within minutes after they are localized

9. No prompt response yet… GRB needs to be < 1 hour old and visible in Maui The few that have been attempted –Bad weather –Bad pointing Several test bursts have been sent –Responses between 1 and 10 minutes One was caught during testing (030329) –Images taken several days after the event GRB 030329

10. A diffraction grating was recently installed on the ABC Low resolving power (8) Installed Jan ’05 A light bulb viewed through the grating, and a star….

11. Simulations of the grating are similar to what is seen 0th 1st 2nd higher orders The blaze angle was chosen so most of the light would be in the 1 st order Blackbody, sun’s temp Image from ABC of a star

12. Simulations of different temperature blackbodies We can differentiate between blue and red stars Hotter temps Cooler temps

13. We can differentiate between different types of objects Star Quasar Symbiotic binary

14. In summary, the ABC is up and running, we’re just waiting for a GRB The ABC can quickly and deeply observe GRBs – First image within minutes of GRB detection – Small 6’ x 6’ field of view – Deep (22 nd mag) images with 10s exposures The ABC has a diffraction grating – Will get early spectral information for GRBs Questions?