The goal of this CREST proposal is to further strengthen the University of Texas at Brownsville's mission of research and education in gravitational wave (GW) astronomy and, by increasing the participation of underrepresented groups, maintain national competitiveness in this area of fundamental physics. This will be achieved by a multi-disciplinary, synergistic combination of sub-projects in three areas that are critical to the success of GW astronomy: data analysis, detector characterization, and astrophysics. The proposed sub-projects, which focus on ground-based GW astronomy in the 10 to 1000 Hz band, will combine with existing activities in low and ultra-low frequency GW detection to create a unique research group in GW astronomy. The goals of each sub-project are timely and in tune with the ongoing developments in GW astronomy. Under data analysis, optimal ways of combining data from a worldwide network of detectors will be developed in order to enable better sensitivity and new science. Methods will be developed to overcome computational bottlenecks in searches for continuous GW sources and for the analysis of data for specific astrophysical models. Novel GW data analysis tools will be developed by adapting promising results from other disciplines. Detector characterization projects will develop sophisticated data mining and automated knowledge discovery tools that will enable GW experimentalists and data analysts to better understand both the detectors and the data. In the astrophysics sub-project, the project will seek to understand LIGO's observational capability in the study of intermediate-mass black hole formation and explore the potential of pulsars as probes of the massive black hole at the Galactic center.
The direct detection of gravitational waves, which will constitute one of the major scientific events of the century, is likely to happen soon after the current upgrades of the interferometers are completed. The past year of NSF funding has already seen the CGWA at the forefront of some major achievements in the field: the LSC andVirgo collaborations succeeded in operating interferometric detectors at and beyond their initial design sensitivity. The ability to detect changes in the 4-km interferometric arms of less than athousandth of the diameter of a proton has started giving information about our universe that we did not have before. We can claim that the era of GW astronomy has already started. The following are examples of scientific results to which the CGWA contributed significantly as amember of the LSC: • Given the unprecedented sensitivity of the detectors, an analysis of the S5 data for a primordialGW background was able to constrain certain models of the very early universe that could have produced these remnant waves. The results were published in Nature. The upper-limit on the strength of the GW background set by this analysis improves upon the previous best indirect limits, including a limit associated with the production of light elements in the early universe, as predicted by the standard model of big-bang nucleosynthesis. • The Crab Nebula, located 6,500 light years away in the constellation Taurus, was formed in a spectacular supernova explosion in 1054. An analysis by the LSC, which appeared in Astrophysical Journal Letters, has shown that no more than 4% of the energy loss of the pulsar is caused by the emission of GWs. • On Feb 1, 2007, the Konus-Wind, Integral, Messenger, and Swift gamma-ray satellites measureda short but intense outburst of energetic gamma rays originating from the direction of the Andromeda galaxy (M31), located 2.5 million light-years away. The majority of such short gamma-ray bursts (GRBs) are thought to emanate from the merger and coalescence of two massive compact objects, such as neutron stars or black holes. At the time of the detection of this GRB (known as GRB070201), the 4-km and 2-km LIGO interferometers at the Hanford facility were in science mode and collecting data. They did not, however,measure any GWs in the aftermath of the burst. That non-detection was itself significant ,indicating the possibility that the source could be a so-called soft gamma repeater, which are less common than binary coalescence events and emit less energetic gamma rays. The broader impacts of the CGWA activity are the result of stressing student participation in scientific meetings at the regional, national, and international levels. Sergio Cantu, a Mexican-American physics major, won best undergraduate presentation OSA-SPIE award at the 2009 Joint meeting of the NSHP-NSBP. Frank Ceballos won best undergraduate poster presentation at the Fall meeting of the Texas Section of the American Physical Sociey (TSAPS) in Oct 2010 and at the Emerging Researchers National (ERN) meetingin Feb 2012. Mauricio Flores, another physics major, won best oral presentation award at the Fall meeting of the TSAPS in Oct 2011. The participation of UTB and even high-school students was highlighted at the NSF website in the 2008 Press Release 08-015, "Texas HS students presentResearch results at National Astronomy conference" . Last year alone, more than 30 presentationswere made by students at several AAS and TSAPS meetings, LSC Meeting-Arcadia, GWP&AW(exGWDAW)-Milwaukee, Amaldi International Conference on Gravitational Waves, Cardiff UK, etc. Graduate student Pablo Daveloza won an international scholarship from LIGO to spendone year performing research at the LIGO Hanford Observatory. There were only two of these scholarships awarded worldwide in 2010.
