Instrumentation Commons^™

Calculating Time Lags From Unevenly Sampled Light Curves, A. Zoghbi, C. Reynolds, E. M. Cackett

Physics and Astronomy Faculty Research Publications

Timing techniques are powerful tools to study dynamical astrophysical phenomena. In the X-ray band, they offer the potential of probing accretion physics down to the event horizon. Recent work has used frequency- and energy-dependent time lags as tools for studying relativistic reverberation around the black holes in several Seyfert galaxies. This was achieved due to the evenly sampled light curves obtained using XMM-Newton. Continuously sampled data are, however, not always available and standard Fourier techniques are not applicable. Here, building on the work of Miller et al., we discuss and use a maximum likelihood method to obtain frequency-dependent lags that …

The Alignment Of The Marshall Grazing Incidence X-Ray Spectrometer (Magixs), Mark Sterrett

Von Braun Symposium Student Posters

No abstract provided.

The Study Of Nuclear Structure Of Neutron-Rich 81ge And Its Contribution In The R-Process Via The Neutron Transfer Reaction 80ge(D,P), Sunghoon Ahn

Doctoral Dissertations

The study of low-lying levels of nuclei near closed shells not only elucidates the evolution of nuclear shell structure far from stability, but also affects estimates of heavy element nucleosynthesis in supernova explosions. Especially, the properties of the low-lying levels in ⁸¹Ge[Germanium 81] are important because the sensitivity study of the r-process pointed out that the properties of the nucleus can affect the final bundance pattern. Also, the spins and parities measurements of the states are essential to understand the shape coexistence in odd-mass N = 49 isotones.

This work describes the study of the odd-mass N = …

Validation Of Data Reduction Interactive Pipeline For Forcast On Sofia, Brent C. Nicklas, William T. Reach, Sachindev S. Shenoy

STAR Program Research Presentations

The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a heavily modified Boeing 747SP aircraft equipped with 2.5 meter reflecting telescope. Among the suite of instruments onboard is the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST). FORCAST features two cameras for short (5-25 microns) and long (25-40 microns) wavelength detection. Making infrared observations in these wavelengths presents a challenge because the telescope and sky emit background radiation magnitudes brighter than the object of interest. Because of this, the raw FORCAST data must be corrected and reduced. The Data Reduction Interactive Pipeline (DRIP) was developed to process all FORCAST data …

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …

Analyzing The Performance Of The Sofia Infrared Telescope, Sarah M. Bass, Jeffrey Van Cleve, Zaheer Ali

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an airborne near-space observatory onboard a modified Boeing 747-SP aircraft, which flies at altitudes of 45,000 ft., above 99% of the Earth’s water vapor. SOFIA contains an effective 2.5 m infrared (IR) telescope that has a dichroic tertiary mirror, reflecting IR and visible wavelengths to the science instrument (SI) and focal plane imager (FPI), respectively. To date, seven different SIs have been designed to cover a wide range of wavelengths and spectral resolutions. Since the telescope operates in the infrared, different techniques, including chopping, nodding, and dithering, are used to reduce the …

Tools And Methods To Optimize The Analysis Of Telescopic Performance Metrics On Sofia, Steven R. Wilson, Holger Jakob, Stefan Teufel, Zaheer Ali, Jeffrey Van Cleve, Brian Eney, Greg Perryman

STAR Program Research Presentations

SOFIA is an infrared observatory mounted on a modified 747 engineered to do infrared astronomy at 45000 feet. The telescope equipment contains a number of sensors and stabilizers that allow the telescope to capture images while mounted in a moving plane. We have developed methods to analyze the performance of the telescope assembly that will help improve the stabilization and image capturing performance of the observatory. Here we present reusable methods to analyze telescope performance data that will enable improvements in the quality of the scientific data that is produced by the SOFIA. This poster focuses on the multi-flight performance …

Flitecam Data Process Validation, Jesse K. Tsai, Sachindev S. Shenoy, Brent Cedric Nicklas, Zaheer Ali, William T. Reach

STAR Program Research Presentations

FLITECAM Data Processing Validation

Many of the challenges that come from working with astronomical imaging arise from the reduction of raw data into scientifically meaningful data. First Light Infrared Test CAMera (FLITECAM) is an infrared camera operating in the 1.0–5.5 μm waveband on board SOFIA (Stratospheric Observatory For Infrared Astronomy). Due to the significant noise from the atmosphere and the camera itself, astronomers have developed many methods to reduce the effects of atmospheric and instrumental emission. The FLITECAM Data Reduction Program (FDRP) is a program, developed at SOFIA Science Center, subtracts darks, removes flats, and dithers images.

This project contains …

Design And Evaluation Of A Fiber Optic Probe As A Means Of Subsurface Planetary Exploration, Robert Paul Pilgrim

Graduate Theses and Dissertations

The Optical Probe for Regolith Analysis (OPRA) is an instrumentation concept designed to provide spectroscopic analysis of the near subsurface of unconsolidated regolith on bodies such as moons, asteroids and planets. Below a chemically altered surface may lay the geological history in the form of stratigraphy that is shielded from degradation due to harsh external environments. Most of what we know about our solar system comes from remote platforms, such as satellites that are deployed into orbit around the target body. In the case of Mars, we have had several successful landers and rovers however, with the exception of the …

Counting Photons To Calibrate A Photometer For Stellar Intensity Interferometry, Jason Chew

Physics

We use a telescope and photometer to observe stellar photons and measure the rate of observed photons. Based on intensity spectra from the Spectrophotometric Catalogue of Stars, we also predict expected values for the photon rates, which we compare to our measurements. From this comparison, we measure the local optical depth to be τ = 0.60±0.25, a reasonable value. We find that our predictions are directly proportional to our measurements by a factor of 0.98 (+0.02, -0.27) . The similarity between our measurements and expectations shows that we are able to both predict and measure photon rates with accuracy.

High Precision K-Shell Photoabsorption Cross Sections For Atomic Oxygen: Experiment And Theory, Brendan M. Mclaughlin, C P. Ballance, K P. Bowen, D J. Gardenghi, Wayne C. Stolte

Wayne C. Stolte

Photoabsorption of atomic oxygen in the energy region below the 1s −1 threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/ΔE ≈ 4250 ± 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 ± 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the …

Discontinuities And Alfvenic Fluctuations In The Solar Wind, G. Paschmann, S. Haaland, B. Sonnerup, T. Knetter

Dartmouth Scholarship

We examine the Alfvenicity of a set of 188 solar wind directional discontinuities (DDs) identified in the Cluster data from 2003 by Knetter (2005), with the objective of separating rotational discontinuities (RDs) from tangential ones (TDs). The DDs occurred over the full range of solar wind velocities and magnetic shear angles. By performing the Walen test in the de Hoffmann–Teller (HT) frame, we show that 77 of the 127 crossings for which a good HT frame was found had plasma flow speeds exceeding 80 % of the Alfven speed at an average angular deviation of 7.7◦; 33 cases had speeds …

Image Processing Algorithms For Improving Planetary Exploration And Understanding, Ali Pouryazdanpanah

College of Engineering: Graduate Celebration Programs

• To design a fully automated tool-set that allows to detect and extract the sky region in planetary images.

• To develop the new method for rock segmentation in planetary stereo images.
• To develop the new method for shadow detection in planetary images

Bayesian Inference Of Polarized Cosmic Microwave Background Power Spectra From Interferometric Data, Ata Karakci, P. M. Sutter, Le Zhang, Emory F. Bunn, Andrei Korotkov, Peter Timbie, Gregory S. Tucker, Benjamin D. Wandelt

Physics Faculty Publications

Detection of B-mode polarization of the cosmic microwave background (CMB) radiation is one of the frontiers of observational cosmology. Because they are an order of magnitude fainter than E-modes, it is quite a challenge to detect B-modes. Having more manageable systematics, interferometers prove to have a substantial advantage over imagers in detecting such faint signals. Here, we present a method for Bayesian inference of power spectra and signal reconstruction from interferometric data of the CMB polarization signal by using the technique of Gibbs sampling. We demonstrate the validity of the method in the flat-sky approximation for a simulation of an …

Chemical Compatibility Study Of Anti-Corrosive Materials For Stratospheric Observatory For Infrared Astronomy (Sofia), Belyn Nicole Grant, Zaheer Ali, Greg Perryman, Stefan Teufel, Brian Eney

STAR Program Research Presentations

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a telescope designed to capture infrared light from deep space, mounted in a highly modified Boeing 747 SP. Portions of the aircraft interior are showing signs of corrosion, and need to be coated with a material that will prevent further corrosion. Up to date, current anti-corrosive materials commonly used on aircrafts are incompatible with the very thin aluminum surface of the telescope mirrors. The purpose of our study is to find an effective corrosion preventive material with low outgassing properties.