NAIC-NRAO Single Dish Summer School 2005


School on Single-Dish Radio Astronomy

July 10-17, 2005, Arecibo, Puerto Rico

Hands-On projects

The following are the hands-on projects planned for the 2005 Single Dish Summer School. The schedule of these projects on the telescopes is available at this link.

Project code: AO-1
Title : Radar Observations of Mercury
Advisor : Dr. J. Harmon (AO)
Students : Sabyasachi Pal, Matt Lykins, Paul Carr, Felipe Perez

The project will be to do a radar imaging observation of Mercury using the long-code delay-Doppler method. The students will take the data, do the delay-Doppler analysis, and generate the final images. These will then be compared with Mariner-10 maps and earlier Arecibo images of the same region. The students will also estimate the total Mercury radar cross section from the data using the radar equation.

Project Code: AO-2
Title : Orbit determination of Binary Pulsars
Advisor : Dr. P. Freire (AO)
Students : Alessandro Corongui, Angel Muneoz, Joseph Foy, Vladislav Kondratiev

In this project, the students will observe a binary pulsar with a short orbital period on several consecutive days. To do that, they will become familiar with the CIMA gui and the Wideband Arecibo Pulsar Processors. They will then learn how to search for pulsars, using several trial dispersion measures, and learn how to fold pulsar data at the pulsar's periodicity, once they find the pulsar's periodicity.
They will then learn how to search for pulsars, using several trial dispersion measures, and learn how to fold pulsar data at the pulsar's periodicity, once they find it.

Project Code: AO-3
Title : OH Masers
Advisor : Dr. M. Lebron (AO)
Students : Tiffany Borders, Eduardo De la Fuente Acosta, Ji-hyun Kang, Emily Mercer,
Mansi Kasliwal

We propose to observe the 18 cm (1665, 1667, 1612, and 1720 MHz), 6 cm (4765, 4751, and 4660 MHz) and 5 cm (6031, 6035, 6049, and 6017 MHz) OH maser lines toward high-mass star-forming regions using the Arecibo Telescope L-band, C-band and C-high receivers. The observations will use the position-switched mode. In this project we will gain experience with the standard AO spectral line observations technique, as well as data calibration. We will also discuss the differences between the ground state and excited OH maser lines. We will compare the measurements with reported values from the literature (when available). Variability in the 5 cm and 6 cm OH lines seems to be common, so we cannot anticipate whether these lines will be detected. As a bonus in this project we will try to include in the OH-line setup, the observations of the methanol maser at 6.7 GHz and the formaldehyde line at 4.8 GHz.

Project Code: AO-4, GBT-4
Title : HI Emission in Extended Galaxies
Advisors : Drs. K. O'Neil (GBT) & C. J. Salter (AO)
Students : Rik Williams, Prasanth Nair, Stephen Redman,
Maarten Baes (AO-4).
                 Sabrina Stierwalt, Sabina Sabatini, Cristy Bredeson, Simona Toscano (GBT-4)

This project is designed to demonstrate the fundamentals of spectral line observing. Two different groups will observe the same galaxies using the GBT (one group) and Arecibo (the 2nd group). Of the galaxies observed, a number have HI emission known to extend beyond the Arecibo beam, while some do not. The results from the two telescopes will be compared to determine the extent of the sources. Beam maps of the Arecibo telescope will also be made, as well as calibration (gain) measurements for both telescopes. These will be used to both to calibrate the data and to aid in understanding the results.

Project Code: AO-5 (Canceled)
Title : Stalking the Cosmic 3-Helium Abundance
Advisor : Dr. T. Bania (BU)

We propose to use Arecibo to derive He-3 abundances in Galactic planetary nebulae (PNe). The cosmic abundance of the He-3 isotope has important implications. He-3 can be used to test the theory of stellar nucleosynthesis; it gives important limits on models of Galactic chemical evolution; it can help constrain Big Bang Nucleosynthesis. We use the hyperfine transition of He-3 at 8665 MHz to derive He-3 abundances in Galactic H-II regions and PNe. We find a lack of substantial He-3 enrichment in the Milky Way interstellar medium which in turn means that the bulk of solar mass stars do not return significant quantities of He-3 to the ISM. This conclusion is based on a small (6 sources) PNe sample which needs to be expanded. Arecibo's superior X-band gain together with its ~30 arcsec beam (an excellent match to many Galactic PN sizes) makes it the instrument of choice for this program.

Project Code: AO-6
Title : Polarization calibration of the central-pixel of ALFA
Advisor : Dr. A. Deshpande (AO)
Students : Nikhil Jethava, Brian Kent, Claudia Cyganowski, Laura Kasian

This experiment will involve full Stokes measurements on a (partially) polarized continuum calibrator using the central pixel of ALFA. The facility to rotate ALFA about its axis will be utilized to sample the variation in the Stokes output as the relative feed angle changes over ± 90 degrees. These measurements will be interpreted appropriately leading to estimates of the on-axis polarization response of the feed, as well as of the polarization properties of the astronomical source. The spectral dependence of the relevant quantities will also be explored. The hands-on experience here will include designing the experiment, actual observations and interpretation of the measurements.

Project Code: GBT-1
Title : Searching for the second double-pulsar binary
Advisor : Dr. S. Ransom (NRAO)
Students : Steve Begin, Julia Deneva, Marta Burgay, James Sheckard

Recently, as part of the early stages of the Pulsar ALFA surveys at Arecibo, the PALFA consortium discovered a highly relativistic binary pulsar in orbit around either a massive white dwarf or another neutron star. If the companion is a neutron star, it seems likely that the discovered pulsar is the second born neutron star in the system, and therefore the original neutron star might still be visible as a pulsar. Another "double-pulsar" system would be a fantastic discovery and would allow many more tests of General Relativity. For this project we will observe the new pulsar system for 3 hrs with the S-band receiver at the GBT using the SPIGOT backend and then search the data for the "other" pulsar.

Project Code: GBT-2
Title : OH Masers/Megamasers
Advisors : Dr. J. Braatz (GBT)
Students : Christopher Aneorve, Marta Cueto, Laura Gomez,
Myriam Cruz, Rachel Osten

We will observe OH maser systems in sources near and far using the GBT L-band receiver and the spectrometer. A position-switching technique will be employed. The observations are rather straightforward, so we will take the opportunity to inspect the calibration in some detail. For example, we will calculate the gain, system temperature and antenna temperature "by hand" and then compare these results with the automated calibration procedures available in the software. We will observe a Galactic star-forming region, where OH emission is bright and easily detected. We will then observe an ultraluminous infrared galaxy. These systems, which produce bright IR emission associated with the collision of gas-rich galaxies, also produce OH "megamasers". We will determine the isotropic luminosities of the Galactic and extragalactic OH maser systems, and learn why the extragalactic maser sources are prefixed by "mega."

Project Code: GBT-3
Title : Galactic HI in Absorption
Advisors : Drs. K. O'Neil, R. Maddlena (GBT)
Students : Samantha Lugo, Alyson Ford, Larry Morgan, Leonidas Dedes

Galactic neutral hydrogen (HI) will be observed in absorption towards a strong continuum source. By observing "off" positions at different places around the continuum source you can elucidate the problem of determining exactly what the "on-source on" spectrum really is. This will also allow the student to determine the opacity and spin temperature of the HI.

Project Code: GBT-5
Title : Molecules in nearby sources
Advisor : Dr. P. Jewell (GBT)
Students : Hyunjoo Kim, Marco Krco, Yvonne Tang, Stevens Johnson

The HC3N molecule will be observed in its J=1-0 transition at 9 GHz in a several different sources, including star forming regions and evolved star outflows. Chemistry and source kinematic differences will be determined, and the basics of molecular spectroscopy in radio astronomy will be illustrated.