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Department Library

2020

Caleb Gaunt (Senior Thesis, April 2020, Advisor: Joseph Moody )

Abstract

ROVOR is Brigham Young University’s remote observatory in Delta, UT that currently runs on TheSkyX software and other scripts. The current system, though, can be complicated and can only be accessed by one student or faculty member at a time. To solve these problems, a new observatory control system is being developed. The new system, Remote Observe, uses a web-based approach to provide easier access and greater extensibility to the system. Remote Observe has a user interface built using React and is hosted by Google Firebase with a database that tracks commands given to the system. Bret Little has programmed these parts to accept modules designed to interface with different pieces of equipment that utilize ASCOM Alpaca drivers, which present the equipment as an HTTP API. In order to complete a proof of concept, I have programmed a controller for a weather monitor and our custom Lifferth dome using Node.js. I researched the tools and libraries needed to accomplish the development of these controllers. After that, I engaged in a test-first development approach by writing code for automated unit tests that would verify the functionality of the controllers. I then developed the code for controllers until they functioned properly. To validate the system as it is, I found an ASCOM-made Alpaca equipment simulator and connected it the controllers, which I registered with the rest of the existing system. After finding a few bugs and writing a few more tests, I modified the code to where the system integrated with the simulator as expected. In the future, the system will be further developed by obtaining Alpaca-compatible equipment to connect the system to, developing the front-end, rewriting the script that controls the Lifferth dome in Node.js, and configuring the whole thing to run on Raspberry Pis onsite in Delta.

2019

Christian D Draper (PhD Dissertation, August 2019, Advisor: Joseph Moody )

Abstract

The population and formation of dwarf galaxies, Mr > −14, contain clues about the nature of dark matter. The best place to search for these dwarf galaxies without influence from nearby large galaxies is within galaxy voids, where no galaxies have yet been found. To search for this potential dwarf galaxy population we have developed and applied a new photometric technique. We use three redshifted Ha filters, designated Ha8, Ha12, and Ha16, along with the Sloan broadband filters, g', r', and i' to identify emission line galaxies. From the ratio of the object flux through the Ha filters, Ha12-Ha8 and Ha12-Ha16, we are able to determine the distance to these galaxies and the strength of the emission line captured in the filter set. One problem with using just the three Ha filters is that the system will be sensitive to any emission line which has been redshifted enough to fall within the set. Of particular concern are the [OII] and [OIII] lines which will contaminate the sample. To overcome this we use a color-color relation, g' - r' and r' - i', to help separate which type of emission has been detected. We have applied this method to search for galaxies within the void FN2 and FN8. From this we have found 23 candidate objects which could have Ha emission placing them inside of the void. To better understand the population density dwarf galaxies through voids we have also modeled the population of objects which we will detect having Ha emission compared to the contamination of back ground objects which we can then use to compare the density in the void with the mean galaxy density. We have also begun taking spectra of the emission objects, to ensure our method does detect emission line objects, to test how well the distance and emission strength determination is, and to begin identifying which type of emission we have detected. To date we have taken spectra on 6 objects. All 6 showed emission, 4 with [OII] and 2 with [OIII]. Though none was Ha we formed a “pseudo-redshift” to determine the accuracy of our measurements. This shows that our method is accurate to -127+-204 km/sec.

Daniel Jones (Senior Thesis, April 2019, Advisor: David Allred, Joseph Moody )

Abstract

Geosynchronous satellites (GEOs) need to be monitored to track their health, effects of space aging, and unexpected maneuvers. This can be accomplished by creating photometric and polarimetric signatures from light curves. To develop our understanding about how the light curves reveal the needed information, we began by studying the 101 W satellite cluster. To create the light curves, observations were taken through Johnson V, B, R, and I filters as well as polarized filters using the telescopes at the Remote Observatory for Variable Object Research (ROVOR) in Delta, UT and at the Optical Delving Infrared iNnovation (ODIN) laboratory at the Kirtland Airforce Base in Albuquerque, NM. To determine the effects of aging, three signatures were compared with archived data for the respective GEOs. We found that dimming and/or reddening occurred. The dimming was equal to 0.1-0.2 mags and the B-V color increased by about 0.1 indicating a reddening by that amount. Using the polarized data, the Stokes parameters were calculated. An increased understanding of the satellite's structure and movements can be obtained by analyzing how these parameters change in a night.

Rochelle Steele (Senior Thesis, April 2019, Advisor: Joseph Moody )

Abstract

No astronomer has yet discovered the dwarf galaxies that many Λ Cold Dark Matter (ΛCDM) simulations predict should be abundant within intergalactic voids. Spectroscopic observations are necessary to identify and determine the distances to these galaxies. However, dwarf galaxies are so faint that it is difficult to observe them with spectroscopic methods. We have developed a way to photometrically identify dwarf galaxies and estimate their distance using three narrowband filters centered on the Hα emission line. From this method, the redshift of the Hα emission line can be estimated, which gives the distance to the galaxy. Equivalent width, or strength, of the emission line detected can also be estimated. The line observed must be verified as Hα emission using observations with Sloan broadband filters. We have primarily studied one void, FN8, using these methods and have found 14 candidate dwarf galaxies, which must still be confirmed spectroscopically. The low density of candidate void galaxies rejects the hypothesis that there is a uniform distribution of dwarf galaxies within the void, as suggested by some ΛCDM simulations.

Nicholas Van Alfen (Senior Thesis, April 2019, Advisor: Joseph Moody )

Abstract

Blazars are active galactic nuclei whose jets point directly at the Earth. By observing the variability in these objects, we can determine their morphology and better understand the distribution of material around a blazar. However, only a handful of blazars are studied regularly. To identify potential candidates for a more in depth study in the future, we observed 192 of the brightest blazars in the northern hemisphere for a year in optical wavelengths with our 16" ROVOR telescope. From our observations, we found 13 blazars displaying a significant level of variability and identified a clear bimodal distribution between smooth an stochastic variability.

2018

Lauren Hindman (Senior Thesis, May 2018, Advisor: Joseph Moody )

Abstract

Blazars, a subclass of Active Galactic Nuclei (AGN), are characterized by a jet of particles accelerated by magnetic fields around supermassive black holes. For blazars, these jets are angled toward Earth. These objects are known to change magnitude, or flare, often and sometimes rapidly. It is thought that two mechalisms are mainly responsible for flaring: geometric instabilities in the jetswhichoccurstochastically,andperiodicchangesinjetoraccretiondiskactivityaddoriendation from orbital perturbations. Using our Remote Observatory for Variable Object Research (ROVOR), we monitored 192 of these objects using both V and R Johnson broadband spectral filters over the course of a year. We comment on the variability observed and which mechanism may be most responsible.

2017

McKay Osborne (Senior Thesis, May 2017, Advisor: Joseph Moody )

Abstract

Blazars are believed to be supermassive black holes in galactic nuclei, emitting high-energy radiation. Despite much theoretical and observational research performed on these enormous masses, the mysteries of their inner dynamics remain unsolved. BYU-owned telescopes (ROVOR and WMO) have monitored the prototypical blazar, Mrk 501, from 2009–2016 at optical wavelengths, searching for any obvious periodicity to its variations in brightness. We performed differential photometry on this data set using Mira and VPhot. The photometric calibration of these data is used to construct a low-noise light curve. Frequency analysis is performed using Period04. The light curve analysis unveils an obvious long-term periodicity of ∼2300 days. Further frequency analysis shows other possible simultaneous periods of lesser duration. These results match expectations for a multibody black hole system.

Joe Rivest (Senior Thesis, May 2017, Advisor: Joseph Moody )

Abstract

Blazar light curves are studied to deepen our understanding of super massive black hole systems. Sinusoidal variations in a light curve are generally a signature of orbital dynamics. We have made and analyzed optical observations of Markarian 501, using Johnson BVR filters, from 2010--2016. In the optical light curve, we find significant evidence for a sinusoidal variation with a period of $\sim2300$ days, or about 6--6.5 years, along with smaller, quasi-periodic variations. In 2000, Rieger \& Mannheim calculated a binary black hole orbital period of 6--14 years, based on the 23-day period found in gamma ray observations, by assuming a bulk Lorentz factor $\Gamma=$10--15 for a helical, relativistic jet, as seen in radio observations. We propose that optical observations reflect the intrinsic orbital period predicted by Rieger \& Mannheim and constrain $\Gamma$ to $\sim10.3$. Further investigation could lead to a gravitational wave profile for Mrk 501 and reveal signature characteristics of future candidates for similar gravity wave sources.

Parkes Whipple (Capstone, July 2017, Advisor: Joseph Moody )

Abstract

Four linearly polarized filters, at 0, 45, 90 and 135 degrees with respect to north, are calibrated for the ROVOR telescope in Delta, UT. Standard non-polarized stars are used to determine the differences in throughput between the four filters. The throughput is found to be equal to within 1%. Standard polarized stars are used to determine the accuracy of the degree of polarization and the offset between the true position angle and our measured position angle. The amplitude, or degree, of polarization is accurate to within 0.5 percentage points. The offset between our instrumental position angle and the true value is found and is given by true = 0:4499(instr)+ 47:322 with an R^2 value of 0.9997. We are confident of the position angle to within 3 degrees. ROVOR is now calibrated and ready to continue polarimetric observations.

2016

Marcus Holden (Senior Thesis, April 2016, Advisor: Joseph Moody )

Abstract

Using the Brigham Young University 16" ROVOR telescope, we have monitored the TeV blazar Markarian 501 for 75 days in 2012 through the Johnson B V R filters. Markarian 501 was stable during this time, serendipitously allowing the opportunity to examine its behavior during long quiescent periods. We unexpectedly discovered a small sinusoidal variation in its magnitude having an amplitude of 0.03 magnitudes and a period of between 113-130 days which is essentially twice the period of the x-ray variation discovered by Abdo, et al. (2011). We present our data and interpret it using a binary orbital model.

Ryan Lesser (Senior Thesis, April 2016, Advisor: Joseph Moody )

Abstract

Photometric redshifts are routinely obtained for galaxies without spectral emission lines using broadband photometry. However, this method does not work if galaxies have emission. For galaxies with emission, it is theoretically possible to obtain reasonably accurate (< 500 km/s) photometric redshift values using "ramp'' filters. Such filters have a linearly increasing/decreasing transmission through the bandpass, causing the intensity of the image to be a function of the wavelength of the emission line. We have obtained a set of ramp filters tuned for isolating Hα at a redshift range of 3,000-9,000 km/s. The set consists of two filters that are nearly linear in transmission, have opposite slope, and cover the wavelength range from 655-680 nm. We add a 2.1 nm FWHM filter centered on the red side of the ramp filters at 697 nm to measure the continuum. Redshifts are derived from the ratio of the ramp filters indices after the continuum has been removed. We recover the redshifts of a test sample of 16 Sey I and Sey II galaxies with an accuracy of 450 km/s. This value can be improved by increasing the wavelength coverage of the ramp filters and measuring the continuum on the blue side as well.

Katrina Pedersen (Senior Thesis, August 2016, Advisor: Joseph Moody )

Abstract

Identifying the chemical composition of unknown satellites is of great interest for defense applications. A developing method of accomplishing this takes low-resolution spectra of satellites and deconvolves them using known material reflection and absorption properties. Using a suitable diffraction grating in the filter wheel slot, test spectra have been obtained over a variety of sun angles for various geostationary satellites using the ROVOR 16’’ RC Optical telescope. The data are encouraging but the analysis is cumbersome and time-intensive. We are developing a data analysis package based on the commercial image-processing software package Mira, to help automate the data reduction process. Using the Mira scripting language and its file event scripting capabilities, data can be automatically processed with limited user interaction. We report on progress to date.

2014

Adam George (Senior Thesis, June 2014, Advisor: Joseph Moody )

Abstract

Non-invasive methods of measuring the composition of blood is of interest in the medical field. One such method is the spectroscopic study of how near-infrared light interacts with a human finger. Modeling theoretically the propagation of photon packets through a simulated multi-layer human finger provides useful information concerning the scattering and back scattering of light. This knowledge will increase the understanding of such medical devices as pulse oximeters and make strides in the possibility of measuring other compositions in blood.

Matthew McNeff (Senior Thesis, August 2014, Advisor: Joseph Moody )

Abstract

We developed and employed a new method for determining the redshift of galaxies between the range of 2000 cz to 10,000 cz. The method involved getting a transmission through sloped blue and red filters, along with a continuum filter. The Moody-Holden-McNeff Relation is detailed, giving the relationship between the transmissions through the filters and the estimated redshift. The data that was collected for 5 nights is outlined along with the 3 different methods of analysis. Despite the fact that the data was cloudy and often had low signal to noise, there is good evidence that the method worked and deserves follow up research. The next step will be to ensure the data is taken on photometric nights.

2013

Nichole Millward Maughan (Masters Thesis, June 2013, Advisor: Joseph Moody )

Abstract

Non-invasive blood analysis devices that can measure characteristics less prominent than the oxygenation of hemoglobin are of interest in the medical community. An important step in creating these devices is to model the interaction of photons with human tissue in increasingly greater physiological detail. We have modeled, using a Monte Carlo technique, the interaction of photons through epidermis, blood and water arranged both in layers and in a homogeneous mixture. We confirm the expected linear relation between photon attenuation and material volumetric percentage in our two-layer models. We discovered that this relationship becomes non-linear in the homogeneously mixed models where volumetric percentage must be replaced with interaction volume percentage. These nonlinearities become significant when the values of the interaction coefficient, µt, differ by an order of magnitude or more and could prove crucial in accurately reading oxygenation or other constituents in the blood and also in modeling radiation delivered to a patient in photodynamic therapy.

Thayne McCombs (Senior Thesis, August 2013, Advisor: Joseph Moody )

Abstract

The Remote Observatory for Variable Object Research (ROVOR) has a backlog of three years of observations that have not been reduced or analyzed. In this Thesis we discuss software we developed to improve the data reduction pipeline and automate many of the necessary steps in re- ducing astronomical data. Specifically, we developed the RedROVOR python package to perform the tasks necessary for reducing data from ROVOR, as well as an online web interface (RovorWeb) which provides an easy to use interface to the RedROVOR toolset, as well as an online observation log management system to keep track of observations made with the ROVOR observatory.

2012

Benjamin Boizelle (Senior Thesis, August 2012, Advisor: Joseph Moody )

Abstract

Using the ROVOR telescope, a long-term (3+ year) monitoring program of low-luminosity AGN has begun. Optical variability of LLAGN as a class are explored to determine how similar these are to classical AGN. This thesis specifically seeks to understand the apparatus, the programs, and the science to allow for precise measurements of what are expected to be small nuclear variations in the 100-target observing list.

2011

Evan Hansen (Senior Thesis, June 2011, Advisor: Joseph Moody )

Abstract

All telescopes face vulnerability to adverse weather conditions during operations. This is particularly true of remote and robotic telescopes, such as ROVOR, which do not have an on-site operator to monitor the weather. To protect ROVOR, a weather station and monitoring program has been developed and constructed to provide a constant watch over the site. The afore mentioned weather station has been in operation for over a year at the time of this writing.

Cynthia Knight (Senior Thesis, April 2011, Advisor: Joseph Moody )

Abstract

Dark matter is one of the greater mysteries in astronomy. It is abundantly evident in galaxy rotation curves and galaxy cluster velocity dispersions. Computer models clearly indicate that the observed large-scale structure of the universe is shaped by it. These same models predict that galaxy voids may contain dark matter in places where galaxies have not yet formed. So studying voids and the galaxies that are most deeply embedded in them is a means of exploring dark matter itself. We have examined the Sloan Digital Sky Survey and have identi fied two true void galaxies de fined as having no other cataloged neighbors within 12 Mpc. These are almost identical and show remarkably similar magnitudes, sizes, and colors. Although just a small sample of two objects, they provide evidence that smaller, dwarf-like galaxies can be found in voids as has been predicted by CDM models

Bret Little (Senior Thesis, April 2011, Advisor: Joseph Moody )

Abstract

CelestialGrid is an all-inclusive observatory system which automates the capture, retrieval, reduction, and long-term archival of astronomical data. In addition to providing a graphical interface for all observatory operations, CelestialGrid simplifies nightly observation planning by automating the capture of star standardization frames. This paper discusses the development, installation, and operation of CelestialGrid.

Jacob Nelson (Senior Thesis, April 2011, Advisor: Joseph Moody )

Abstract

It is likely that the nuclei of all galaxies contain black holes. If matter falls in toward the black hole, some of it can be heated an ejected creating an active nucleus. Astronomers monitor the infall and estimate black hole masses by measuring variations in the brightness of the nuclei. If all galaxies contain nuclear black holes, then all of them should vary in brightness, not just those termed active. The variability of these normal galactic nuclei will be less since a higher variability would have placed them in the active class. Using data obtained with a robotic telescope from 2004 to 2007, I investigated the variability in their nuclei.

2010

Brian K Bucklein (PhD Dissertation, July 2010, Advisor: Joseph Moody )

Abstract

We investigate several techniques to identify voids in the galaxy distribution of matter in the universe. We utilize galaxy number counts as a function of apparent magnitude and Wolf plots to search a two- or three-dimensional data set in a pencil-beam fashion to locate voids within the field of view. The technique is able to distinguish between voids that represent simply a decrease in density as well as those that show a build up of galaxies on the front or back side of the void. This method turns out to be primarily useable only at relatively short range (out to about 200 Mpc). Beyond this distance, the characteristics indicating a void become increasingly difficult to separate from the statistical background noise. We apply the technique to a very simplified model as well as to the Millennium Run dark matter simulation. We then compare results with those obtained on the Sloan Digital Sky Survey. We also created the Watershed Void Examiner (WaVE) which treats densities in a fashion similar to elevation on a topographical map, and then we allow the “terrain” to flood. The flooded low-lying regions are identified as voids, which are allowed to grow and merge as the level of flooding becomes higher (the overdensity threshold increases). Void statistics can be calculated for each void. We also determine that within the Millennium Run semi-analytic galaxy catalog, the walls that separate the voids are permeable at a scale of 4 Mpc. For each resolution that we tested, there existed a characteristic density at which the walls could be penetrated, allowing a single void to grow to dominate the volume. With WaVE, we are able to get comparable results to those previously published, but often with fewer choices of parameters that could bias the results. We are also able to determine the the density at which the number of voids peaks for different resolutions as well as the expected number of void galaxies. The number of void galaxies is amazingly consistent at an overdensity of −0.600 at all resolutions, indicating that this could be a good choice for comparing models.

Cameron Pace (Senior Thesis, May 2010, Advisor: Joseph Moody )

Abstract

We have prepared magnitudes for 42 comparison stars near five very-high energy blazars. Some of these stars have been previously calibrated by others, and in general our magnitudes agree with these previously reported magnitudes. We have used transformation equations to tie our magnitudes into the standard stars established by Landolt (2009). Our I band magnitudes are systematically fainter than those previously presented, but we must conclude that our measurements are correct as they are tied into the Landolt standards.

Richard Pearson (Senior Thesis, May 2010, Advisor: Joseph Moody )

Abstract

The remote telescope facility of Brigham Young University, ROVOR, observed Mk501, a variable blazar, for over 60 nights. These observations took place from April 2009 to March 2010. Possible microvariability (10 to 30min) was found in three nights, thereby limiting the size and mass of the central black hole within Mk501. No periodic behavior was identified, but intranight variations occurred daily. SBP photometry, a new reduction method, was first used to analyze the Mk501 data. However, the method requires a larger, brighter object; M81 was therefore observed and SBP photometry was performed to prove the quality of the SBP photometry data. A variation of 0:005 +- 0:001mag was found over a period of 2-minutes, thus verifying the usefulness of this reduction method. Additionally, tools to help with ROVOR operation are included.

2008

Jonathan Daniels (Senior Thesis, August 2008, Advisor: Joseph Moody )

Abstract

On October ninth of 2006 a supernova was discovered in the galaxy UGC 4904. It was designated SN 2006jc. This SN is thought to be either a type Ib, a type Ic, or a type Ibc supernova. The progenitor star is thought to have been a Wolf-Rayet star that had a massive eruption two years before the supernova. Alternatively the progenitor may have been a Wolf-Rayet Star in a binary system with the LBV star that had the outburst. We observed this SN for 23 nights from October 26, 2006 to January 3, 2007 using the Tenagra II telescope. These observations were made in V, R, and I filters. We reduced the data and graphed the SN magnitude versus Julian date to make light curves for the three filters. The data obtained and analyzed in this thesis are part of the Swift SN Multi-wavelength Monitoring Project. Based on our light curve we can’t distinguish between type Ib, Ic, or Ibc.

Janalee Harrison (Senior Thesis, December 2008, Advisor: Joseph Moody )

Abstract

Active Galactic Nuclei are galaxy nuclei that emit non-thermal radiation. The standard model describing them assumes the radiation originates from a black hole surrounded by an accretion disk. This model can be tested by measuring how fast the light from the AGN varies. We have constructed and commissioned a 16” telescope named ROVOR (Remote Observatory for Variable Object Research) to monitor AGN light and other variable objects. We report on the first scientifically significant data obtained with ROVOR. For this data we made observations on the blazar 1ES 1959+650 in the Fall of 2008 as part of a multi-wavelength campaign. We discuss how this is compatible with the standard model.

2007

Eric Allan (Senior Thesis, August 2007, Advisor: Joseph Moody )

Abstract

Photometry of galactic nuclei is a difficult task due mainly to extreme obscuration and light contamination from the nuclear bulge. To reach accuracy levels that are of interest astrophysically (on the order of 0.05 to 0.001 magnitudes) requires careful observing techniques and special reduction algorithms. In this paper we make a comparison between standard aperture photometry and DAO photometry–a point spread fitting technique–to illustrate the pros and cons of using these techniques to obtain brightnesses of galactic nuclei. We will show that the DAO method seems to be more effective in all cases, but its accuracy is inconclusive. We will provide some data for a further comparison between these two techniques and a third bulge fitting technique.

Adam Johanson (Senior Thesis, April 2007, Advisor: Joseph Moody )

Abstract

Active galactic nucleus or “AGN” refers to any galactic nucleus that emits non-thermal radiation. Arguments based on energy requirements, light travel times, and limited observational imaging data strongly suggest that the radiation is coming from a supermassive black hole surrounded by an accretion disk. Details of the accretion disk and its surrounding material are only known in theory since no disk is close enough or unobscured enough to be imaged. The only direct probe of the disk environment comes from looking at how energy from flares in the disk “reverberate” through the surrounding gas clouds and re-emerge as emission lines. We are laying the foundation of a long-term multi year campaign of reverberation mapping by measuring the nuclear flaring or variability of the nearby edge on normal galaxies M81 and M101. We report on aperture photometry on these galaxy nuclei, compared with reported reference stars.

2006

Aaron Paget (Capstone, June 2006, Advisor: Joseph Moody )

Abstract

In order to assure safe operational conditions for the ROVOR telescope, safe atmospheric conditions must be verified. An established weather station provides data valuable in verifying conditions. Using barometric, temperature, relative humidity, and sensors in conjunction with an anemometer interfacing with LabView, the weather station will determine 1) condensation temperatures to protect the mirrors, 2) Protection from wind and rain, 3) Using the adiabatic rate to determine cloud level in order to assess meaningful observational conditions. This demonstrates detectable atmospheric conditions for safe astronomical observations, allowing remote operation of ROVOR to proceed safely.

2005

Christopher Olsen (Senior Thesis, August 2005, Advisor: Joseph Moody )

Abstract

n/a

2004

Peter Brown (Senior Thesis, August 2004, Advisor: Joseph Moody )

Abstract

n/a

Joseph Hopper (Senior Thesis, January 2004, Advisor: Joseph Moody )

Abstract

n/a

Stephen Richard McNeil (PhD Dissertation, August 2004, Advisor: Joseph Moody )

Abstract

A new photometry technique is developed for the detection of small-amplitude optical variability in galactic nuclei. This technique utilizes the surface brightness profiles of galaxies and checks for nuclear variations by matching up the bulge profiles (assumed to be constant). With this method optical variability is measured down to two hundredths of a magnitude. The method is tested on the following six galaxies using a B-Johnson and an R-Cousins filter: M51, M101, M81, M94, NGC4395, and NGC3982. These galaxies constitute a sampling of normal, LINER, and Seyfert galaxies. Although normal and LINER galaxies are thought to have no optical variability in their nucleus, our study concludes that most galaxies show some optical variability over the timescales of months and years. A study on deconvolution is also carried out as a possible way to improve the new technique. However, none of the tested algorithms improved the ability to detect small-amplitude nuclear variations down to hundredths of a magnitude.

2002

Jonathan Barnes (Masters Thesis, December 2002, Advisor: Joseph Moody )

Abstract

The GoldHelox project is a telescope designed to image the sun in X-ray wavelengths from within the payload bay of the space shuttle. Several processes and tests are required to satisfy the NASA safety requirements for flight including passing through at least two safety phases named Phase 0/1 and Phase 2/3. Each phase includes a rigorous written defense of the safety of a payload showing the steps taken during the design and fabrication of hardware to meet the NASA safety requirements. This thesis contains the GoldHelox Phase 0/1 Safety Certification documents as well as description of their creation.

Jacob P. Fugal (Honors Thesis, April 2002, Advisor: Joseph Moody )

Abstract

1998

David Rich Miller (Masters Thesis, April 1998, Advisor: Joseph Moody )

Abstract

A theoretical model of an optical synthetic aperture interferometer has been constructed using Mathematica to predict and analyze the plausibility and effectiveness of constructing such a system. Model elements have been modeled after both theoretical and empirical data sets. The model is patterned largely around the classical Hanbury-Brown and Twiss interferometric principle with appropriate changes and modifications to accommodate a visible light optical application. The model has been built in a compartment manner. Each compartment can be run either as a stand-alone segment or together as an integrated composite solution. Single or multiple variables can be varied during each run of the model yielding both single degree of freedom solutions as well as multi-variable analysis. Multiple runs of the model have been generated to explore the theoretical and practical limits of such a stellar interferometer. Specifically, sampling rate variations, baseline and geometric variations, and photon flux and noise variations have been analyzed.

Peter W A Roming (PhD Dissertation, August 1998, Advisor: Joseph Moody )

Abstract

Using long-split spectra centered in wavelength about Hα, a velocity map of a 20” x 140” east-west box centered on the nuclear region of M101 and an “hourglass” shaped object centered 50” from the nucleus of M33 has been obtained. The velocity resolution is 2.5 km/s and the spatial resolution is approximately 1” east-west and variable (3-4” on average) north-south for the M101 data while the velocity resolution is 0.22 km/s and the spatial resolution is approximately 0.68” along each slit for the M33 data. Temperature, electron density, shock, and ionization fraction maps of the same regions have also been obtained using the [NII](λ6548), [NII](λ6583), and [sII](λ6731) lines. The M101 data are consistent with gas infalling toward the nucleus as part of streaming motion along a previously discovered molecular bar. The streaming motions are traveling west-to-east on the north side of the nucleus and east-to-west on the south side of the nucleus. The two bright knots, situated north and south of the nucleus are a result of a gas pileup at the inner Lindblad resonances. There is a local instability, probably due to non-circular motions, in which the motion of the gas southwest of the nucleus is moving west-to-east creating a collision of the two opposing gas motions in a region of relatively high density and temperature. A blue arc emanating from an unresolved source on or near the nucleus shows evidence of collision in this same high density and temperature region. The M33 data are consistent with gas infalling toward the center of the sampled region. A preliminary model is presented to explain this phenomenon. In addition to the long-slit spectral analysis of M33, ultra-narrow-band (FWHM ≈8.5 Å) Hβ on-and off-line images were obtained of this galaxy. Using an image multiplication-subtraction method, maps that differentiate between HII regions, OB associations, and broad-line Hβ regions, which may be identified with intermediate sized black holes, were created. Using these maps, a spectrum of the broad-line Hβ regions can be obtained to substantiate the presence of Seyfert activity.

1997

Bryan Lee Paul (Masters Thesis, April 1997, Advisor: Joseph Moody )

Abstract

This thesis is a study of the Center for Astrophysics Redshift Catalog, concentrating on nearby voids. A list of the individual surveys contributing to the CfA Redshift Catalog is presented, which can be used to determine how deeply a specific area of the sky has been searched, the observational biases present in the catalog are discussed, as well as general structure present. Faint galaxies are found to either follow the structure already outlined by bright galaxies or create their own structures; there is no indication of a uniform distribution of faint galaxies which populates voids. There are indications of structures whose brightest members have absolute magnitudes of MB = -18 or fainter. A list of nearby (cz &lt; 5000) voids is presented. Many of the voids are not crossed by any deep surveys; in fact, the surveys often define the edges of the voids. Thus the question remains whether even these nearby voids are truly empty.

Michael Dean Rice (Masters Thesis, August 1997, Advisor: Joseph Moody )

Abstract

Using the method for determining galaxy types outlined in Eric Hintz’s 1995 Dissertation, I classified 2109 galaxies in Supercluster 4. To do this, I used the Burrell Schmidt telescope in Kitt Peak National Observatory to image six Abell clusters with 4 square field of view in the Johnson B and I filters. The supercluster contained 60% Hintz type 1 and type 2 galaxies (elliptical and S0), 30% type 3 and type 4 (spirals), and 10% other type. All galaxies are catalogued according to image position and contain magnitude (B&I), color (B-I), r25, pixel radius and magnitude error

1995

Eric George Bow Hintz (PhD Dissertation, August 1995, Advisor: Joseph Moody )

Abstract

Bessel BVRI photometric information is presented for 961 galaxies and 384 stars from the central 1 Mpc of six rich Abell clusters. These clusters are fitting functions and an asymptotic magnitude was determined. One fitting function produces a shape parameter β which , when taken in combination with the color index (B-I), shows a breakdown of the three basic morphological types (E, S0, and S) into six β-types. In addition, the β parameter provides a method of star-galaxy separation which was 96% efficient. The breakdown of the galaxies into six β-types provides a probe into the nature of the rich Abell clusters. Examinations of the luminosity functions, overall color indices, and counts of the various β-types show differences in the clusters based on their Rood-Sastry type. These differences may provide clues to the underlying physics for the creation and evolution of these clusters.

Peter W A Roming (Masters Thesis, April 1995, Advisor: Joseph Moody )

Abstract

Observations of five spiral galaxies were made in various band passes with the Burrell-Schmidt telescope. Using an image multiplication-subtraction method, an indicator was established that differentiates between HII regions, OB associations, and broad-line Hα regions which may be associated with intermediate sized black holes. Now that these broad-line regions are identified an optical spectra can verify the existence of an intermediate mass black hole. While searching for these intermediate mass black holes, Hα on-line and off-line CCD images of M101 revealed the presence of two Hα bright, filled knots paired linearly across the nucleus in a north-south orientation. The knots are centered 2.5” from the nucleus and lie roughly perpendicular to an east-west molecular bar. Each knot in turn is connected to an elongated, photoionized ring lying parallel along the bar. Redshift data shows that the knots and rings originate form matter flowing out of a bipolar nuclear “geyser”. The past two geyser eruptions have apparently triggered star formation to the west and to the south of the nucleus. We estimate that the geyser has flowed alternately stronger on one side, and then on the other, with a period of approximately 22 million years. The redshift data and Hubble Space Telescope Planetary Camera image data indicate that the southern side may now be relatively quiescent while the northern side is more active, the outflow could be caused by a 106 M black hole orbiting within the nucleus, sweeping material from the molecular bar.

1994

Kristen Adams (Honors Thesis, July 1994, Advisor: Joseph Moody )

Abstract