Research Projects by Subject

Note: If a research project is listed as having openings for more than one SIP intern, it should be assumed that the interns are expected to work collaboratively on the same project and/or data set. This may preclude rising seniors from submitting papers based on such projects to the Intel Science Talent Search competition.

Astronomy & Astrophysics

Code Research Project Descriptions
AST-01 Title: Stellar Isotope Survey at Lick Observatory (SISLO)
Primary Mentor: Dr. Evan Kirby
Secondary Mentor: Prof. Raja GuhaThakurta
Number of Interns: 2

Spectroscopy is an astronomer’s favorite tool for measuring the compositions of stars. Different elements absorb light at different wavelengths. Stars with a lot of carbon, for example, absorb lots of light around 430 nm. It is nice to know the amount of an element in a star, but the most detailed study of the composition of a star is to measure how each element is distributed among its constituent isotopes (atoms with the same number of protons but different numbers of neutrons). The SIP students will learn how to measure the isotopic compositions of stars and track how the isotopes change over the course of the Milky Way Galaxy’s history. The student will use data already collected from the Hamilton spectrograph at Lick Observatory. You can learn more about SISLO from the original proposal to use the Hamilton spectrograph. SISLO is seeking two highly motivated SIP students who are adept at independent learning. The students should work well together as a team. Previous computer programming experience or a desire to learn about computer programming is required. The primary mentor for this project, Dr. Evan Kirby, is a postdoctoral researcher at UC Irvine in southern California. The students should have the means and be willing to visit Irvine once or twice during the summer for 3-5 days per trip. The remainder of the communication with the primary mentor will be conducted over e-mail and Skype.

AST-02 Title: Cycling of Chemicals in the Gaseous Phase of the Large and Small Magellanic Clouds
Primary Mentor: Dr. Jessica Werk
[Faculty Contact: Prof. J. Xavier Prochaska] Number of Interns: 2

Most of the atoms in your body were fused in the cores of stars. An understanding of their journey requires a picture of how gases cycle into and out of stars and, ultimately, into and out of galaxies. The Large and Small Magellanic clouds are our nearest neighbor galaxies — currently being cannibalized by the Milky Way halo — and serve as excellent laboratories in which to study the physical properties of gaseous material associated with stars and the interstellar medium. In this project, you will learn about emission line and absorption line spectroscopy. Ultimately, these experiments can tell us about what galaxies and stars are doing with their gas.

AST-03 Title: Modeling and Analysis of the Spectra of Exoplanets
Primary Mentor: Ms. Caroline Morley
Secondary Mentor: Prof. Jonathan Fortney
Number of Interns: 2

Over 1000 exoplanets — planets around stars other than the Sun — have now been discovered. This project will involve characterizing the atmospheres of exoplanets and determining their compositions. You will use computer simulations of planetary atmospheres to understand what a planet of a specific temperature and composition will look like. Each molecule has its own unique fingerprint; that is, based on the quantum physics of the molecule, it absorbs strongly at specific colors (called wavelengths) and more weakly at other wavelengths. Based on which molecules form as a function of height, we can calculate how bright the planet will be at different wavelengths, which we call a spectrum. Exoplanets are very challenging to observe because they are faint and extremely close to their stars, which are very bright. However, we know that giant planets and stars are actually made of the same basic building blocks: mostly hydrogen and helium, plus an additional assortment of elements that make up a few percent of the total mass. There is a class of objects called “brown dwarfs” that form like stars, but are much less massive, so they are never able to start the nuclear fusion of hydrogen that defines stars and makes them hot and bright. It turns out that these brown dwarfs can have the same temperatures as planets, but are floating by themselves in space instead of orbiting a star, so they’re much easier to observe. In this project, we will try to understand the similarities and differences between brown dwarfs and planets. In particular, we will look at the planetary-mass free-floating brown dwarfs which have recently been discovered, and compare those objects to planets of the same temperatures.

AST-04 Project cancelled!
The project “Hierarchy in Galaxy Groups: Separating Central and Satellite Galaxies over 8 Billion Years” has been cancelled due to the unavailability of the mentor.

AST-05 Title: Uranus and Neptune Interior Models
Primary Mentor: Dr. Nadine Nettelmann[Faculty Contact: Prof. Jonathan Fortney] Number of Interns: 1

Little is known about the interior structure of Uranus and Neptune, despite their importance in our understanding of the formation of the solar system and of the class of detected extrasolar Neptune-sized planets. Moreover, standard planetary structure models of the ice giants that have been developed since the Voyager era fail to agree with recent HST-and ground based atmospheric abundance measurements. Therefore, advanced ice giant planets models need to be computed. Such models will assume a super-adiabatic interior with a compositional gradient. The new interior models will be designed to match the observed CO and CH4 abundances of Uranus and Neptune. The prospective student is supposed to let a PC compute advanced Uranus and Neptune interior models. For that purpose the student will use an existing code and run it repeatedly. Programming language skills are not required but the student will get the opportunity to become familiar with the C++ language. Depending on interest and performance the student may develop sub-routines for generating compositional and temperatures profiles a priori, to be read-in by the main program for the structure calculation. The student will gain insight to the state-of-the art assumptions about planetary interiors including the bulk composition of the solar system planets. Perhaps most importantly, the student can learn how progress on a highly specific topic is at the mercy of progress in various fields and thus benefits from communication between different research groups.

AST-06 Title: Studying the Nature of Dwarf Elliptical Nuclei and Globular Cluster Satellites
Primary Mentor: Dr. Elisa Toloba
Secondary Mentor: Prof. Raja GuhaThakurta
Number of Interns: 2

The goal of this project is to learn about the origin of the nuclei observed in dwarf elliptical galaxies. Some theories suggest that these nuclei may have formed from the merging of globular clusters (groups of stars that orbit a galaxy) that have migrated to the center of the dwarf elliptical galaxy. We have obtained Keck/DEIMOS spectra of a sample of 300 globular cluster candidates around 21 different dwarf elliptical galaxies. The SIP student will analyze the properties of these globular cluster candidates to remove sample contaminants (objects that are not globular clusters). The student will then use the technique of spectral co-addition to analyze the spectroscopic properties of the globular clusters and compare them to the properties of the 21 dwarf elliptical nuclei.

AST-07 Title: Kinematic Anomalies in the Rotation Curves of Dwarf Elliptical Galaxies
Primary Mentor: Dr. Elisa Toloba
Secondary Mentor: Prof. Raja GuhaThakurta
Number of Interns: 2

The goal of this project is to quantify the degree of regularity and symmetry of the rotation curves of the stellar component of dwarf elliptical galaxies. Dwarf ellipticals are thought to have originated from star-forming disk galaxies that have been transformed into puffed up quenched galaxies by their environment. The anomalies and asymmetries in their rotation curves provide important constraints on how the environment transforms these galaxies. The SIP student will collect the rotation curves of the nearly 80 dwarf ellipticals published in the literature and will apply the new statistical analysis techniques that our team has recently developed to quantify the strength of these irregularities and asymmetries. The irregularities and asymmetries will be analyzed in the context of environmental and internal properties of the dwarf elliptical galaxies.

AST-08 Title: Supermassive Black Holes at the Centers of Galaxies
Primary Mentor: Dr. Martin Gaskell
Number of Interns: 3

This project involves studying the variability of the light emitted as supermassive black holes in the centers of galaxies swallow gas. These black holes are typically ten million to more than a hundred million times more massive than our sun. The role of the students is to measure the brightness from images taken with various optical telescopes, to compare these variations in brightness with data taken by satellites, and to work on related issues of data reduction and analysis so that the results can be published. The aim of the research is to understand why the energy output varies so dramatically with time. This project is part of an international collaboration.

AST-09 Title: How do Galaxies Grow in their Old Age?
Primary Mentor: Dr. Guillermo Barro[Faculty Contact: Prof. David Koo] Number of Interns: 2

Red elliptical galaxies are thought to be the final stage in the life-cycle of galaxies. They are the most massive galaxies in the nearby Universe, and appear red because they have ceased forming stars. How elliptical galaxies become so large, continuing to grow even after their star formation has ended, remains poorly understood. We aim to study the close environments of very distant galaxies, seen at a time when the Universe was only 2 billion years old, to determine if galaxy collisions play a key role in creating the most massive and oldest galaxies. This work will make use of very high-quality data products developed by astronomers in the CANDELS survey, including the visual analysis of deepest and highest resolution optical and near-infrared imaging data ever taken by the Hubble Space Telescope. This video illustrates the formation process of one of such galaxies showing the heavy bombardment of small systems at late times.

AST-10 Title: Galaxy Evolution
Primary Mentor: Mr. Hassen Yesuf[Faculty Contacts: Profs. David Koo and Sandra Faber] Number of Interns: 2

There are several interesting projects on the general theme of galaxy evolution that the two SIP students can work on. For instance, gas accretion onto galaxies and its ejection by galactic winds are two important processes in shaping the properties of galaxies but they are still poorly understood (read this paper for background information). The SIP students will use Python scripts to combine the spectra of 2000 distant galaxies from the DEEP3 survey. The galaxies are so distant that they are seen at a time when the Universe was about half of its present age. Another possible project will involve studying outflows in Active Galactic Nuclei (AGN, galaxies with active black holes) and green valley galaxies (GV, galaxies transition from star-forming to being quiescent). This project will involve using Python scripts to combine tens of thousands of spectra of nearby galaxies from the SDSS survey. The aim of the project is to check if there is a connection between outflows and galaxy quenching (i.e, transformation from star-forming to quiescent). For background information, the student can read this paper. A third possible project involves writing Python machine classification (learning) algorithm (in particular Neural Network) to automate and access the reliability of the on-going visual (human) classification of distant galaxies in the CANDELS survey. A fourth possible project involves studying the correlation between black hole mass and the central density of galaxies.

AST-11 Title: The Motion of Wisps in the Crab Nebular Supernova Remnant
Primary Mentor: Mr. Alexander Rudy
Secondary Mentor: Prof. Claire Max
Number of Interns: 2

The Crab Nebula is a supernova remnant, the remains of a giant star that exploded in the year 1050AD. At the center of the nebula is a neutron star, surrounded by gas left over from the massive explosion 1000 years ago. The rotating neutron star at the center of the nebula (called a pulsar, for the 33ms interval pulses it emits) lights up the large cloud of gas, and powers jets and ripples that move away from the pulsar. Here is a movie of this phenomenon. Although the movements of the ripples (called “wisps” in the Crab Nebula) has been measured over the course of a year before, we have data that suggest that the wisps move at a much faster speed when they are close to the pulsar. This project would develop an analysis and measurement technique for the moving wisps using data from the Keck telescopes in the near-infrared. The SIP interns will measure the wisp motion and attempt to connect the motion of the wisps that we measure when they are close to the pulsar with the published motion of the wisps when they are far from the pulsar. In the course of developing a novel analysis technique for the wisps, we may expand the scope of the project to consider motions in the nebula outside the wisps. Interested students should be prepared to get comfortable with linear algebra.

AST-12 Title: Flux Calibration of Keck/DEIMOS Spectra: Extracting Physically Meaningful Information for Andromeda and Milky Way Stars
Primary Mentor: Ms. Katherine Hamren
Secondary Mentor: Prof. Raja GuhaThakurta
Number of Interns: 1

The UCSC-based SPLASH survey (Spectroscopic and Photometric Landscape of Andromeda’s Stellar Halo) has to date collected ~15,000 spectra of stars in our nearest galactic neighbor, the Andromeda Galaxy. These spectra have so far been used for a variety of purposes, including understanding the kinematics of Andromeda’s various components, and pinpointing unusual stars. Before the spectra can be used to their fullest extent, however, they need to be “flux calibrated” – i.e., the spectra’s flux values must be converted to physically meaningful units. Flux calibration of an object depends on the details of the observation in which the spectra were obtained such as airmass, parallactic angle, seeing, and position of the object in the focal plane. We are looking for 1-2 SIP interns to flux calibrate the SPLASH spectra, thereby helping future astronomers understand both the properties of stars in Andromeda and the exact response of the DEIMOS spectrograph. The SIP interns will gain a deep understanding of the relationship between an instrument, an observation, and the final science.

AST-13 Title: Spectral Typing the SPLASH Sample
Primary Mentor: Ms. Katherine Hamren
Secondary Mentor: Prof. Raja GuhaThakurta
Number of Interns: 1

The Andromeda galaxy is a special laboratory in which astronomers can study a galaxy at all sc