Dr. Speck will study the precise nature of dust grains around low- and intermediate-mass stars (LIMS) because (1) this is where the dust originates before being expelled into the interstellar medium (ISM) and participating in many other astrophysical processes, and thus knowing its initial states will allow for a more accurate prediction of its fate in and effect on the ISM and beyond and (2) the environment around most of these LIMS is relatively benign and thus has simplified chemistry, which facilitates the understanding of the processes in play. Dr. Speck will use a range of techniques including spectroscopy, imaging and modeling, incorporating new laboratory data and taking into account theoretical models and meteoritic studies to provide knowledge of the nature of dust forming around LIMS. This study will also assess how dust formation changes with stellar evolution. In this way, the effect of chemistry and density on dust formation can be determined, allowing testing and refinement of existing models for dust formation and evolution and which can be applied to many astrophysical environments.
One of the major problems in investigating circumstellar dust is that it incorporates so many apparently disparate aspects of the physical sciences (physics, astronomy, geology, and chemistry). In order to provide a background and framework for such knowledge, Dr. Speck will introduce an upper level/graduate astrophysics course in cosmochemistry that will be open to students from other departments as well. Dr. Speck's research is specifically designed to involve students at all levels (undergraduate, masters and doctoral) and therefore breaks down into modular chunks. In this way the research undertaken also allows for training of students at these various levels. Dr. Speck will continue her effort to recruit and mentor female graduate students as well as students from other underrepresented groups.
This award is funded by the NSF Division of Astronomical Sciences
The overarching goal of this NSF CAREER project was to improve our understanding of dust in space (cosmic dust) and its impact on the surrounding environment, while simultaneously training the next generation of scientists to be critical thinkers as well as excellent researchers, teachers and public outreachers. Cosmic dust pertains to basic questions of galactic processes; dust needs to be well understood in its own right, if we are to understand its contribution to many aspects of astrophysics. Even a small quantity of dust has a profound impact on energy flow. For example, in 1991 Mt Pinatubo ejected enough dust into our atmosphere to cause global cooling by ~0.1K, but we did not perceive the dust to be dulling our skies. In space, the interaction of light with dust has profound consequences for evolution of its environment. For instance, the formation of new planets depends on dust in a collapsing cloud. Furthermore, my cosmic dust studies have direct relevance to issues of climate change we are currently facing on Earth. This research project research was intrinsically multidisciplinary; the study of cosmic dust requires a combination of chemistry, mineralogy, isotope geochemistry and physical optics, as well as IR astronomy and stellar evolution We have successfully challenged many aspects of the conventional wisdom regarding dust in space especially with respect to chemistry and astromineralogy (i.e. composition, crystal structure, grain size and shape). In particular, we have shown that assumptions about stardust are not consistent with observations. This work also spawned two new projects in Laboratory Astrophysics and led to several new collaborations. This project has funded 14 undergraduate research students and five graduate RAs (including one completed PhD dissertation and one completed Masters thesis). It has led to 37 conference presentations (mostly by students) and helped to fund all the research students to attend at least one conference. Five graduate students were able to attend a big international conference in Germany, thus promoting US astrophysics in Europe. There are eight refereed publications from this project with three manuscripts in preparation at this time. In addition to student training and basic science research, this grant has provided many opportunities for working with the general public. PI Speck instigated a highly successful public talk series called Cosmic Conversations (http://stardust.missouri.edu/CosmicConversations/ -started in September 2007), aimed at both outreach and training of students to give public talks. The development of training of graduate students in public outreach has since been transferred to training graduate student in the local NSF IGERT program and has been presented at a Science Communication conference. In addition, PI Speck developed a multi-disciplinary upper level undergraduate/graduate course on Cosmochemistry. My biggest achievements have been a combination of archival research in space telescope observations and overturning conventional wisdom about cosmic dust. Much astronomical data is publicly available but most if it still hasn’t been mined to its fullest extent. I have found unusual objects whose properties do not fit within current paradigms and force us to rethink our hypotheses on dust formation and processing
