Check out a recent article about my work in New Scientist magazine (online):
New evidence for extragalactic life-forming matter,
...from the work printed in the Astronomical Journal: Lawton et al. 2008, AJ, 136, 994L.
I am interested in finding the building blocks of life in our Universe. To that end I am working with Dr. Chris Churchill and collaborators to chart the existence of organic molecules in extragalactic sources. These organic molecules, known as polycyclic aromatic hydrocarbons (PAHs), are thought to be the sources of several absorption features labeled diffuse interstellar bands (DIBs), seen mostly in highly reddened stars within our own Galaxy. There are currently over 200 known DIB lines that fall mostly in the visible portion of the electromagnetic spectrum (at rest wavelength). Nobody has ever done a survey for these objects in extragalactic sources; although, there are a few known instances of DIBs in other galaxies. This is mostly to do with the difficulty in detecting the DIBs; most have equivalent widths measured in milli-Angstroms. I will use Quasar absorption line systems to probe for DIBs in extragalactic space. Recently, I have extended my studies into supernovae and strong neutral sodium (NaI) absorbing galaxies. Supernovae have the advantage of being embedded sources; therefore, they may more accurately probe the ISM of a galaxy. NaI absorbers are interesting in that there is a strong correlation of DIB strength with Galactic NaI absorption. Placing limits on DIB strengths within these environments will allow us to make some judgments on the DIB carriers themselves.
Due to the difficulty in detecting DIBs, I will narrow my search down by using other elements that appear to be good tracers of DIBs. DIB strengths tend to follow neutral hydrogen column density very well in that the more neutral hydrogen you have the stronger the DIBs. As stated, neutral sodium (NaI) also tends to be a good tracer and is easier to search for because the NaI doublet falls roughly in the middle of the visible part of the spectrum. Therefore, I will do a survey of NaI using the Sloan Digital Sky Survey. Those systems that have NaI will become my candidates for follow-up observations to search for DIBs. Besides NaI, other tracer elements are being considered as well. A successful survey will tell us a great deal about the abundance of organic molecules in the relatively nearby (low-redshift) Universe.
Dr. Churchill and I are also searching for DIBs at high redshift with collaborators Prof. Sara Ellison, Prof. Theodore P. Snow and Prof. Don York from the University of Victoria, the University of Colorado at Boulder, and the University of Chicago, respectively. The collaboration has been granted 14 hours of Gemini time and two nights of VLT time for this purpose. A list of NaI candidates is not necessary for high-redshift objects because there is already currently an abundance of sources with high neutral hydrogen column densities known. I have recently presented our work at the International Astronomical Union's Colloquium 199 in Shanghai, China. We will present our findings at the International Astronomical Unions Symposium 231 in Monterey, CA in August.
Grants & Awards
I have been awarded the NASA GSRP grant through the Office of Space Science for my research explained above. Previously, I have the been awarded Space Grant through the New Mexico Space Grant Consortium. I have to give my thanks to both the NASA Office of Space Science and the New Mexico Space Grant Consortium as their funding is greatly helping me fulfill my research goals.
October 2006-July 2007: GSC Executive Officer - As the Executive Officer of the Graduate Student Council I was the graduate student representative on many student and administrative councils. As a member of the Associated Students of New Mexico State University (ASNMSU) elections board I saw to it that the Spring 2007 ASNMSU elections were fairly run. As a member of the NMSU Plan2Plan Taskforce I was the graduate student representative that gave input on how the University should best go about completing a strategic plan. More specifically, I was a member of a subcommittee charged with directing how the University should go about completing a comprehensive environmental scan. Finally, I was also a member of the NMSU Heritage Council charged with giving input on how to best preserve the history of NMSU's various contributors.
March 2006-October 2006: GSC Vice President - As the Vice President of the Graduate Student Council at NMSU I sat on the funding board of the GSC and was very involved in increasing graduate student participation in student government here at NMSU. The funding board's main purpose is to decide which graduate students and graduate student organizations are deserving of monetary support from the GSC. This is usually based on which graduate students and organizations have done the most outreach for the community.
August 2005-May 2006: AGSO President - The Astronomy Graduate Student Organization's President at NMSU. My responsibilities for this position included being a conduit through which faculty and graduate students communicate official department business. I am also the official spokesperson for the graduate students in University matters. It is my job to see that the graduate students' voices in our department are heard.
August 2004-May 2005: AGSO Vice-President - In charge of setting up graduate students in our Astronomy department with outreach opportunities in the greater Las Cruces area. Each graduate student in our department is responsible for doing two outreach experiences per semester. These can include giving talks at local elementary schools and middle schools, running observing nights throughout Las Cruces, and corroborating with the Las Cruces Astronomical Society for special events. Our department has a long history of outreach to the community.
August 2003-May 2004: Head-TA - In charge of seeing that all astronomy graduate student TAs have the necessary information and materials to teach their courses. I am the spokesperson for the graduate students in all matters related to teaching the introductory astronomy classes. My responsibility also includes working with faculty to better our courses and creating/altering laboratory experiments for our Astronomy 110 introductory classes.
I successfully defended my PhD Thesis, Diffuse Interstellar Bands in Damped
Lyman-Alpha and Starburst Galaxies, on July 14, 2008. I have accepted
a postdoctoral position at the Space Telescope Science Institute in Baltimore,
working with Dr. Karl Gordon on studying interstellar dust.