Korean Collaborators at the Ewha Womans University have expertise in fabricating an unusual type of MEMS (microelectro-mechanical) mirror array with a very large angular travel. We have expertise in astrophysical instrumentation and investigations. In order to apply the MEMS micromirror devices to astrophysics, we need to work with our collaborators in Korea to demonstrate that the devices can be scaled up in size, and refined to improve specific performance goals relevant to astrophysics observations, including the PSF spread. We therefore propose to work with our Korean collaborators to move our projects forward to the formal instrument proposal stage.
The proposed activity will make new astrophysics instrumentation possible. One application will allow pointed observations of astrophysical transients at least three orders of magnitude faster than ever before, opening up a completely new parameter space for inquiry. An obvious application is the study of optical emission from gamma-ray bursts, where observations of fast-peaking optical emission would be greatly advanced. A second application would bring a radical new technology to bear on multi-object and integral field spectroscopy, offering an alternative to previous fiber optic systems.
UCB/SSL and Ewha will work together to build up new experimental astrophysics knowledge at Ewha, particularly among their post-doctoral researchers and students, while our UCB post-doctoral researchers and students will receive training and hands-on experience with MEMS mirror devices and instrumentation. Our group has collaborative education programs with exceptional engineering students at various universities and colleges in our area. These students will participate in our activities, including the development and operation of our instruments, in order to broaden participation of this student population in astrophysics, space research, and international collaborations. This student population is largely made up of groups that are underrepresented and underserved in astrophysics, space research, and international collaborations, including a large fraction of Hispanic students.
Gamma Ray Bursts (GRB) are the most powerful events in the Universe releasing in a few seconds or less as much energy as a star does in its entire life or a supernova does in many days. These violent events are not well understood though the second class that takes many seconds is thought to be the results of the collapse of the core of a supermassive star that is forming a black hole that sends out two back to back relativistic jets that punch through the shell of material of the exploding and dying star. The other class of GRBs which have typical times scales of a second or less do not have confirmed sources but are much speculated about. Hundreds of GRB optical (viible to your eye) light curves have been measured since the discovery of optical afterglows. However, even after nearly 7 years of operation of the Swift Observatory, only a handful of measurements have been made soon (within a minute) after the gamma ray signal. This lack of early observations fails to address burst physics at short time scales associated with prompt emissions and progenitors. Because of this lack of sub-minute data, the characteristics of the rise phase of optical light curve of short-hard type GRB and rapid-rising GRB, which may account for ~30% of all GRB, remain practically unknown. We have developed methods and prototype instruments for reaching sub-minute and sub-second timescales in a small spacecraft observatory. Rather than slewing the entire spacecraft to aim the optical instrument at the GRB position, we use rapidly moving mirror to redirect our optical beam. As a first step, we employ motorized slewing mirror telescope (SMT), which can point to the event within one second. The two instruments were to be flown onboard the Lomonosov satellite to be launched in 2012. However, the Russian Federation space program has undergone a number of delays and the launch is now tentatively (used since there have been three scheduled launches and then put off as the time approached) for launch in February 2014. Our pathfinder sub-minute measurements of the optical emission of a few GRB each year will result in a more rigorous test of current models that have internal shock and collisions in the relativistic beams, probe the extremes of bulk Lorentz factors measuring how very relativitistic the beam are, provide the first early and detailed measurements of fast-rise GRB optical light curves, and help verify the prospect of GRB as a new standard candle. If the Pathfinder is successful then it makes sense to build a larger scale version. Our collaboration has developed, fabricated, tested, calibrated, and delivered two instruments. The first is Burst Alert Detector (BAT) which detects the GRB from its gamma-rays and x-rays and find the postion roughly - that is within one half degree on the sky. The second is the slewing mirror telescope (SMT) which can take the trigger and pointing information from the BAT and automatically point at the GRB and image it at higher resolution (about an arcminute or 1/60th of a degree) in the optical (visible band) and ultraviolet. The SMT can record its observations but also provide an alert to other larger telescopes, mostly ground-based, to make follow up observations with more precision. The instruments have been delivered to the Russian Federation space agency where the collaboration team members tested and recalibrated the instruments and they were bolted to the Lomonosov spacecraft. They have been there waiting for launch for a time approaching two years. A significant number of students both undergraduate and graduate were involved and had the chance to work on cutting edge science and projects in a large international colloboration.