DOI

10.17077/etd.kr65x1ol

Document Type

Dissertation

Date of Degree

Spring 2017

Degree Name

PhD (Doctor of Philosophy)

Degree In

Physics

First Advisor

Lang, Cornelia

First Committee Member

Mutel, Robert

Second Committee Member

Gayley, Kenneth

Third Committee Member

Fu, Hai

Fourth Committee Member

Cole, Renee

Abstract

The mysterious radio source N3 appears to be located within the vicinity of the Radio Arc region of the Galactic Center. To investigate the nature of this source, we have conducted radio observations with the VLA and the VLBA. Continuum observations between 2 and 50 GHz reveal that N3 is an extremely compact and bright source with a non-thermal spectrum. Molecular line observations with the VLA reveal a compact molecular cloud adjacent to N3 in projection. The properties of this cloud are consistent with other galactic center clouds. We are able to rule out several hypotheses for the nature of N3, though a micro-blazar origin cannot be ruled out.

Robotic Telescope systems are now seeing widespread deployment as both teaching and research instruments. While these systems have traditionally been able to produce high quality images, these systems have lacked the capability to conduct spectroscopic observations. To enable spectroscopic observations on the Iowa Robotic Observatory, we have developed a low cost (~ $500), low resolution (R ~ 300) spectrometer which mounts inside a modified filter wheel and a moderate cost (~ $5000), medium resolution (R ~ 8000) fiber-fed spectrometer. Software has been developed to operate both instruments robotically and calibration pipelines are being developed to automate calibration of the data.

The University of Iowa offers several introductory astronomy laboratory courses taken by many hundreds of students each semester. To improve student learning in these laboratory courses, we have worked to integrate active learning into laboratory activities. We present the pedagogical approaches used to develop and update the laboratory activities and present an inventory of the current laboratory exercises. Using the inventory, we make observations of the strengths and weaknesses of the current exercises and provide suggestions for future refinement of the astronomy laboratory curriculum.

Public Abstract

The center of our Galaxy is home to many intruguing objects. One of these objects, called N3, lies ontop of the bright, non-thermal filaments in a region known as the Radio Arc. To investigate the nature of N3, we have conducted radio observations using some of the worlds most powerful radio telescopes. Broad-band observations of the region reveal that N3 is an extremely compact and bright source with a non-thermal spectrum. Narrow-band molecular line observations reveal a compact molecular cloud adjacent to N3. We show that the properties of this cloud are consistent with other galactic center clouds. We are able to rule out several hypotheses for the nature of N3, though a micro-blazar origin cannot be ruled out.

Robotic Telescope systems are now seeing widespread deployment as both teaching and research instruments. While these systems have traditionally been able to produce high quality images, these systems have lacked the capability to conduct spectroscopic observations. To enable spectroscopic observations on the Iowa Robotic Observatory, we have developed a low cost, high sensitivity spectrometer which mounts inside a modified filter wheel as well as a moderate cost, medium resolution spectrometer which recieves light from a fiber optic cable. Software has been developed to operate both instruments robotically and calibration pipelines are being developed to automate calibration of the data.

The University of Iowa offers several introductory astronomy laboratory courses taken by many hundreds of students each semester. To improve student learning in these laboratory courses, we have worked to design activities wich actively enguage and challenge students. We present the pedagogical approaches used to develop and update the laboratory activities and present an inventory of the current laboratory exercises. Using the inventory, we make observations of the strengths and weaknesses of the current exercises and provide suggestions for future refinement of the astronomy laboratory curriculum.

Keywords

Education, Galactic Center, Robotic Telescopes, Spectroscopy

Pages

xiii, 137 pages

Bibliography

Includes bibliographical references (pages 132-137).

Copyright

Copyright © 2017 Dominic Alesio Ludovici

Included in

Physics Commons

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