Emily's Universe

Undergraduate Research

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I worked on various research projects while I was an undergrad at the Department of Physics at the University of Puerto Rico at Mayagüez. Most of these projects were during my various summer internships, but there was also research that I did with a professor in the department, as well as small research projects for some of the senior-level courses. In this page you can find information about all those projects, as well as links to the presentations and/or papers involved in each project.

PoST Pixel Differentiation at Low X-Ray Energies (Summer 2003)

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During the Summer of 2003 I worked at NASA's Goddard Space Flight Center in Greenbelt, Maryland, as part of the Summer Institute in Engineering and Computer Applications (SIECA) Program. My advisor during the summer was Dr. Enectalí Figueroa-Feliciano (who is currently a professor at MIT).

The Constellation-X mission is one of NASA's future big observatories, and it will be the successor of the Chandra X-Ray Observatory. A detector which is currently being designed and tested for Con-X is the quantum calorimeter. One type of calorimeter that allows for spectroscopy and imaging of extended x-ray sources as well as position determination of x-ray hits is called a Position Sensitive Transition-Edge Sensor (PoST). There is currently a problem with the data analysis algorithms for PoST detectors. At low x-ray energies, the algorithms are incapable of pixel differentiation, which is crucial for achieving complete position resolution. My main job was to develop a code that I called "DrawGroups", which takes as input the pixellated data and determines the separation between pixels and the amount of overlap at low x-ray energies. By testing different input data sets, the program helped me determine which method of data analysis works better (gives a smaller overlap between pixels). I also had other smaller contributions to the project, by doing some lab work (liquid nitrogen and liquid helium transfers, drawing some circuit diagrams, re-wiring an electronics control panel and soldering some connectors). My results were presented in a written report and also in a presentation I gave at the SIECA Intern Presentations on 29 July 2003. I won the NASA/GSFC Rahsaan Jackson Presentation Award for my presentation (they gave me the award a couple of days later).

Senior Seminars and Class Projects (Fall 2002 - Spring 2003)

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During my senior year at UPR Mayagüez I was taking two courses (one each semester) titled "Undergraduate Seminar I & II". In these courses, students had to do a little "research project", which consisted basically of "library research", so to speak. Each person chose a topic in an area related to contemporary physics and prepared a one-hour seminar (which was open to the whole department) and a written report.

My project for the first semester was titled "Evolución Estelar" ("Stellar Evolution"). It was a survey of the current theory of stellar evolution: star formation, nuclear reactions (pp and CNO cycles), evolution of low mass stars and massive stars, and stellar deaths (planetary nebulae & white dwarfs, supernovae & neutron stars, and black holes). I presented this seminar on 9 October 2002.

My project for the second semester was titled "La historia del Universo" ("The History of the Universe"). This was part historical development of cosmological ideas and part evolution of the Universe. I talked about the static Universe model and Einstein's cosmological constant, then Hubble and the expanding Universe. Then I explained the mathematical foundations of modern cosmology (the Robertson-Walker metric, the Friedmann equation, the equation of state, the density parameter, etc), and the Big Bang and Inflationary theories. Then I talked about astronomical observations that support these theories (CMB), and about recent observations that indicate the existence of dark matter (galaxy rotation curves) and dark energy (type Ia supernovae). Then I talked about the very recent WMAP results, the current accepted values of the cosmological parameters, and the future of cosmological research (projects that are being planned right now). This seminar was presented on 28 April 2003.

Also, during my Senior year, first semester, I did a report for the Relativity class on Gravitational Waves (the title was "Ondas Gravitacionales"). I had never read about gravitational waves, so this was my first excursion into the field... Then, during the second semester, I did a report on Dark Enegy for the Quantum 2 class, titled "La Energía del Vacío y la Constante Cosmológica" ("Vacuum Energy and the Cosmological Constant"). This report talked about the vacuum energy in quantum field theory and how this is a possible explanation for the cosmological constant.

Search for Pulsations in Metal Deficient Field Giants (Summer 2002)

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During the Summer of 2002 I worked at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, where I was a Smithsonian Astrophysical Observatory Summer Intern. My advisor was Dr. Andrea Dupree and my mentor was Dr. Jason Aufdenberg. My work there consisted of doing spectroscopic analysis of the Hα (the hydrogen alpha absorption line at 6562.8 Å) region of the spectrum of eight selected metal deficient field red giants, looking for emission wing asymmetries and time variations that would indicate chromospheric motions and pulsations in the stars. The time was not enough to finish all the stars; however I did manage to finish the analysis of six out of the eight stellar targets, which is pretty good for a ten-week internship. The results were presented in the SAO Intern Symposium on 14 August 2002, and later in a poster in the 201st Meeting of the American Astronomical Society in Seattle, Washington (6 January 2003).

Diffraction Effects in SURF Beamline 3 (Summer 2001)

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During the Summer of 2001 I worked at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, under the supervision of Dr. Eric Shirley. My work consisted in creating a mathematical model of the radiation field from a synchrotron, using the Schwinger equations for the vector and scalar potentials, in order to model diffraction effects and minimize or account for them in Beamline 3 at the Synchrotron Ultraviolet Radiation Facility (SURF III) in the NIST Gaithersburg campus. I ran out of time before I was able to finish mapping the radiation field; however, the preliminary results were presented in the Summer Undergraduate Research Fellows (SURF; yes, another SURF, different from SURF III, which was the synchrotron) Colloquium on 10 August 2001.

Investigations of Single Pulses from Radio Pulsars (Spring 2001 - Fall 2002)

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From Spring 2001 to Fall 2002 I was research assistant to Dr. Leszek Nowakowski in the Physics Department at UPR-Mayagüez. We had data of single pulses from several radio pulsars, taken with the Arecibo Radiotelescope, and my job consisted in analyzing them using specifically developed FORTRAN and MathCad programs. We were looking for mode switching, nulling and drifting subpulses. The purpose of this study was to determine the height of the emission region in the pulsar magnetosphere, by means of studying the relation between the width and the intensity of the pulses. I presented results from this work in two different ocassions at the Puerto Rico Interdisciplinary Scientific Meeting (on 10 March 2001 and 16 March 2002). Note that the presentations may seem incomplete; this is because all the data plots were shown in transparencies.

Last Updated: 21 February 2008