SUMMER 2002 RESEARCH POSITIONS WITH KNAC

Deadline: 9:00 am Tuesday, February 19, 2002

We will be making the KNAC summer exchange available to undergraduate students from Colgate, Haverford/Bryn Mawr, Middlebury, Swarthmore, Vassar, Wellesley, Wesleyan, and Williams once more during the summer of 2002. Some job descriptions will be available in early February, but meanwhile, you should be begin thinking about your application and requesting references.

Please note that this experience is meant to be beneficial to both you and the faculty involved. Thus, we hope you will learn a lot and have fun, but faculty also hope that we will accomplish some research ourselves. Although the major thrust of the research is described below, sometimes, equipment and/or weather and/or other circumstances may require some changes. For all positions you are expected to work for ten forty-hour weeks, to have a paper written for the fall KNAC symposium by the end of your summer internship, and to present a paper at the symposium to be held at Swarthmore/Haverford in the fall.

Applications and supporting material should be emailed to pbenson@wellesley.edu by 9:00 AM February 19. The application should include: your name, social security number (please note if you are not a US citizen), institution and class, current mailing address, email address and phone, permanent address and phone (if possible list a place we can reach you during spring vacation), and a list of the courses you have taken in Astronomy, Physics, Mathematics, and Computer Science along with the final grade you received in these courses. This should be followed by a short essay giving any other information or experience which might help you be selected for a job. This is where you can "sell" yourself as the best candidate for a job. If you have any special requirements and/or requests, or interest in a particular topic or location, this is where that information should be put. Unless you state otherwise in the essay, we will assume that you are willing to take any of the positions offered. Note, that I prefer Microsoft Word attachments, but if you use another word processor, please include the text in the body of your email.

In addition, please ask two faculty to email a reference (preferably as a Word attachment) for you to pbenson@wellesley.edu by 9 AM Feb 19. This means you should ask them well before that date!

If you have questions about the program, please ask your astronomy faculty.


ECLIPSE OBSERVATIONS


Faculty Advisor: Jay Pasachoff, Williams College
Email: Jay.M.Pasachoff@williams.edu

The Williams College Eclipse Team is studying the heating of the solar corona and the structure and polarization of the coronal magnetic field by observing total solar eclipses. They are studying data from the total eclipse of 21 June 2001, which they observed from Lusaka, Zambia, and are preparing and testing equipment for the total eclipse of 4 December 2002, which they will observe from Ceduna, Australia. See http://www.eclipses.info . The experiments and past observations are described at http://www.williams.edu/astronomy/eclipse in press releases for which there are links under the 1999 and 2001 eclipses. A Keck exchange student could join Williams College students in working on the 2001 data and preparing for the 2002 expedition. Useful skills include IRAF or IDL, CCD usage and control, optical or electronic experience, and academic excellence.


H II Regions in the SINGG Galaxy Survey


Faculty Advisor: Debra Elmegreen, Vassar College
Email: elmegreen@vassar.edu

Ionized gas in galaxies is observed optically by the red H II regions that surround young high mass stars, and so provides a probe of star formation activity. The Survey for Ionization in Neutral-Gas Galaxies (SINGG) is a national observatory study of H alpha emission in galaxies selected on the basis of their atomic hydrogen (H I) content. We will use public data from this survey to examine the detailed properties of high mass star formation within two dozen southern hemisphere barred and non-barred galaxies covering a range of Hubble types. The images include narrow-band and R-band continuum emission, which we will measure using IRAF (the national data reduction facility). The results of our analysis will provide insight into the disk dynamics that govern star formation on a large scale in different types of galaxies.

A student working with me should have a strong interest in astronomy, and preferably have taken an intermediate-level course in galaxies or general astrophysics. Familiarity with IRAF, unix computers, and spreadsheets on Mac or pc computers is desirable.


Variability of Quasars and Active Galactic Nuclei


Faculty Advisor: Thomas J. Balonek, Colgate University
Email: tbalonek@mail.colgate.edu

The optical (VRI) continuum brightness and variations in a sample of quasars and active galaxies have been intensely studied over a thirteen year period with the Colgate telescope and CCD camera system. (In addition, some fields contain variable stars which must be identified and studied.) Complementary observing programs are being conducted by colleagues at national and international radio and optical observatories and with space telescopes. As part of your summer research, you will actively participate in the observations for this ongoing project, learning all stages of image acquisition, calibration and photometric analysis of CCD images. In addition to analyzing images which you obtain, you will analyze archival images obtained at Colgate's Foggy Bottom Observatory and other telescopes. This project may be of particular interest to students with little or no prior observing experience (who want a thorough exposure to observing) or to those students who enjoy the summer evening skies.


Planetary Nebula Studies


Faculty Advisor: Karen Kwitter, Williams College
Email: Karen.B.Kwitter@williams.edu

1. Heavy Elements in Planetary Nebulae

We have 3 nights on the KPNO 4-m telescope with the echelle spectrograph late this June, to study 2 planetary nebulae at high spectral dispersion. In addition to the easily identified lines of light elements like helium, oxygen, nitrogen, and sulfur, we hope to identify and measure weak emission lines of several ionization stages of iron and several other heavier metals. In particular we are interested in seeing if there is a correlation between iron abundance and oxygen abundance in the nebula; if so, then planetary nebulae might serve as abundance markers in distant galaxies where individual stars are too faint to observe, but planetary nebulae are identifiable and measurable.

The KNAC student would come observing in June and would participate in the data reduction and analysis during the summer. The KNAC student should be familiar with basic concepts of stellar evolution and have some experience with IRAF.

2. Web-Accessible Database of Planetary Nebula Spectra

Over the past several years, colleagues and I have amassed moderate-resolution spectra from 3700-9600 angstroms for more than 80 planetary nebulae in our Galaxy. We would like to make this unique, homogeneous dataset available on the web. Ideally, this would include images of each spectrum, along with options for downloading these images as well as the digital xy values for each spectrum. We would also like to link each spectrum to the best available images of each nebula. There's probably more that will be possible - limited only by the student's web skills and creativity but that's all I can think of for now.

No previous knowledge of planetary nebulae is necessary, but it IS important for the KNAC student to possess the necessary web skills to make this happen, because I don't!


KISS - A survey for emission-line galaxies.


Faculty Advisor: John Salzer, Wesleyan University
Email: slaz@astro.wesleyan.edu

Project Description: We are carrying out a major, long-term survey for extragalactic emission-line objects such as starbursting galaxies, Seyfert galaxies, and quasars. Known as KISS (KPNO International Spectroscopic Survey), our goal is to survey a large region of the sky to faint magnitudes for objects which display the tell-tale signs of activity: strong emission lines. More information about the KISS project can be found on our web page:

http://www.astro.wesleyan.edu/~slaz/research/kiss

We would like to invite a student to work with us this summer on the KISS project. This Keck summer research assistant will be involved in the following activities: learning basic image processing techniques; assisting in the process of reducing the KISS data and generating lists of emission-line objects; carrying out a specific research project using the KISS data and writing a research paper based on your results. The nature of this specific research project can depend in part on the interests and background of the student. There are a wide variety of possible research projects using the KISS data.


Star Formation Regions


Faculty Advisor: Eric Jensen, Swarthmore College
Email: ejensen1@swarthmore.edu

Most regions of active star formation are easily identified by the presence of large quantities of molecular gas and dust. However, in the past 10 years a number of stars have been found that appear to be young, but which are located far from known star-forming regions. These stars are interesting because a number of them are quite near Earth, in some cases only 20-40 parsecs away, while the nearest known star-forming regions are 120-140 parsecs away. Thus, they offer a chance to study star and planet formation up close. I have been carrying out a survey to look for such stars, and I seek a student to help with the analysis of some aspect of the survey data. Possible projects include determining the iron abundance in the spectrum of the well-studied young star TW Hya, whose x-ray spectrum is very iron deficient; measuring lithium abundances in young star candidates to help constrain their ages; or searching the 2MASS infrared survey catalog to constrain the number of binary systems in known star-forming regions. For more information, see http://astro.swarthmore.edu/~jensen/young_near.html .

The ideal candidate will have a strong interest in understanding how stars and planets form and good computer skills. Familiarity with astronomical data analysis, IRAF, IDL, Linux, and computer programming are all strong pluses.


Spectrographic Instrumentation and Observation


Faculty Advisor: Stephen Ratcliff
Email: ratcliff@jaguar.middlebury.edu

The student will assist in the development of the spectrographic instrumentation at the Middlebury College Observatory and will take part in the summer's observing program, which will consist of stellar radial velocity studies, as well as some astronomical photometry.


In Search of Young, Hot Planets


Faculty Advisor: Kim McLeod, Wellesley College
Email: kmcleod@wellesley.edu

Thanks to discoveries in the past five years, we can now say definitively that planets orbit other stars. We infer their existence from their gravitational effects, but we have neither seen them directly nor assembled a decent census of their occurrence. To look for planets directly, I have been using the Hubble Space Telescope to image ~100 low-mass stars and brown dwarfs in the nearby open cluster IC348. These objects are old enough that their protoplanetary disks have likely dissipated, but still young enough that any of their giant planets should still be luminous from the heat of formation. Thus, the cluster provides a good opportunity to see planets directly. Furthermore, because the stars in IC348 are of the most common type, this program is important for determining the frequency of planetary systems in the Universe. All of the data for this project have been reduced, but there is still much analysis to be done. The student working with me would help to locate and choose candidate planets for followup observations.


Stars, Planets, Disks, Magnetic Fields and Rotation


Faculty advisor: Bill Herbst
Email: wherbst@wesleyan.edu

By monitoring the brightness of stars in young clusters we can study a variety of phenomena that are important during stellar formation. A wealth of data on such objects has been accumulated over the years at Wesleyan and elsewhere, and we have only scratched the surface in terms of mining it for science. This project would involve having a student participate in all aspects of the photometric monitoring program - from observing to data reduction and archiving - and would include a particular emphasis on stars with large amplitude, irregular variability. The very cause of these enigmatic variations is still debated and it will be necessary to explore possibilities to see if observational tests can be devised and carried out. Ultimately, we would like to learn how the accretion rates on pre-main sequence stars vary with time and whether there is verifiable evidence for occultation by circumstellar disk matter in some stars. All of this can be related to clues found in our own solar system of what the formation time was like.

A basic knowledge of computers is useful and assumed. Familiarity with IRAF, IDL and/or programming techniques is a plus. Physics background will also be helpful.


Pulsars and/or the Cosmic Dipole


Faculty advisor: Froney Crawford
Email: fcrawfor@haverford.edu

Galactic Radio Imaging of Young Pulsar Fields

The recent Parkes Multibeam Pulsar Survey has discovered a large number of young radio pulsars in the Galaxy which could have associated radio supernova remnants and pulsar wind nebulae. These can be discovered and studied through radio imaging, and several of these young pulsars have already been observed with the Australia Telescope Compact Array (ATCA) radio interferometer. Data from some of these observations await processing at Haverford, and other new young pulsars may be imaged in the near future. An interested student would assist in both the installation of analysis software and the data processing (mapping) for some of these pulsar systems. The student may also help prepare a list of young pulsar candidates which have not yet been imaged for use in a future observing proposal using the ATCA or Very Large Array. Prior experience with data reduction on UNIX/Linux systems and some familiarity with radio imaging software (MIRIAD, KARMA) would be advantageous.

Search for the Cosmic Dipole Effect

The motion of the Earth relative to a putative isotropic rest frame of background sources introduces a dipole anisotropy in the observed source distribution owing to relativistic effects. Detecting this dipole effect in discrete radio catalogs can characterize the distribution of radio sources at an intermediate redshift between the cosmic microwave background and the local universe. The NRAO VLA Sky Survey (NVSS) currently represents the best radio survey with which to try to detect the dipole effect in discrete radio catalogs. The interested student would first help work out the theoretical basis by which this effect could be detected in discrete radio source catalogs. Some work on this has already been done but needs to be carefully checked and reviewed. The student would then consider the feasibility of detecting the dipole effect using a novel analysis technique. We then would consider analyzing the NVSS catalog itself using this technique, depending on the reliability of the survey calibration. The latter part of this project would employ a Monte Carlo approach to testing the observed source distribution against the null hypothesis of isotropy and requires some programming skills.

Improvement of Pulsar Search Software

With the availability of computer memory banks of gigabyte and larger size, it has now become feasible to consider a pulsar search processing method in which an entire pulsar data set is read from disk into memory, processed in-core, then written out to disk. Such a program could be made highly portable if written in C and could be made to run on inexpensive Linux machines. This would be a valuable contribution to the pulsar community and could be used in future searches. The interested student would work on writing code in C which would first read in raw pulsar search data and apply a trial dedispersion to it. Developed software would be tested against existing code to ensure that the results are consistent. The dedispersion code could then interface with code developed at McGill University which performs a sophisticated search analysis on the dedispersed data. A student with significant programming expertise in C and an interest in scientific computing would be ideal for this project (note that the student must have advanced programming skills in C for this project).

GBT Search for Pulsars in Galactic Supernova Remnants

With the availability of the Green Bank Telescope (GBT) in West Virginia, new sensitive searches of SNRs for radio pulsars can be made. Collaborators and I plan to propose for time on the GBT radio telescope to search for young radio pulsars in cataloged Galactic SNRs. Any pulsars found in the search would be observed regularly to obtain timing parameters. The interested student could participate in preparing for the search by helping to create observing schedules, researching and compiling information about the SNR targets (and perhaps other possible targets), and installing search software on local workstations. There may also be the opportunity for the student to travel to the GBT to help take data for this project at some point.


Galactic Streams / Galaxy Inclinations


Faculty advisor: Juan Cabanela
Email: jcabanel@haverford.edu

Here are two potential projects that KNAC students could work with me on. I am not expecting students to have had extensive programming experience, but both projects would require a student comfortable with basic programming (any language is OK, although I have used FORTRAN, C, and Perl to get my work done).

LOOKING FOR GALACTIC STREAMS

The discovery in the mid-1990s of the Sagittarius dwarf galaxy so close to the Galactic plane and the earlier discovery of the Magellanic stream have made it clear that the Galaxy has had a significant history of interactions with other (smaller) galaxies and globular clusters. It is clear from our idea of how and when the Galaxy formed that many globular clusters have engaged in several passes through the Galactic plane, during which time we expect some of the stars to be stripped, continuing along in a similar orbit, but gravitationally unbound form the globular cluster. I propose to look for evidence of stellar streams stripped from globular clusters by using the Minnesota Automated Plate Scanner catalog of the POSS I, which has accurate positions and photometry for over 70 million stars. The student will be responsible for retrieving the data from the catalog and then writing code to compute star counts in azimuthal bins around globular cluster centers in order to determine if there is any anisotropy in the counts indicative of stellar streams.

EXAMINING THE EFFECT OF INCLINATION ON GALAXY APPEARANCE IN THE 2MASS

One of the key concerns in extragalactic astronomy is dust. And despite all the effects extinction within our Galaxy and internal extinction in other galaxies can cause, it is still not clear the extent to which dust affects the appearance of galaxies. One of the simple tests one can perform is to examine a large number of galaxies of the same morphological type and examine how their mean diameters and fluxes change with increasing inclination. An optically thick galaxy dominated by dust should change little in diameter with increasing inclination to the line of sight whereas an optically thin galaxy should appear larger as it becomes more edge-on. My previous research into this problem resulted in the potentially strange discovery that the appearance of late-type spirals (spirals with small bulges and loosely wound arms) are more affected by inclination than early-type (tightly wound) spirals. This was unexpected since the paradigm is that more tightly-wound spirals have higher dust content. I propose to have a student work with me on examining recently released data from the Two Micron All Sky Survey (2MASS) Extended Point Source Catalog to track this effect in the near infrared where dust (in theory) should not affect galaxy appearance much. Comparing these results with previous optical work should prove very enlightening.


Eric Jensen <ejensen1@swarthmore.edu>
Last modified: Mon Feb 11 22:24:11 2002