This is the unofficial website of the NSF AAPF program, run by the fellows themselves. For official information about the fellowship, please go to the NSF program announcement.
This year's AAPF symposium will be held from Saturday 5 Jan 12:00 PM - Sunday 6 Jan 5:15 PM in room 4C-1 at the Washington State Convention Center prior to the 233rd meeting of the American Astronomical Society.
We encourage all AAS attendees to come to our symposium! However we suggest you arrive at or after 2:30pm on Saturday, since the first two and a half hours will be mainly NSF AAPF logistics and internal discussion.
Participants are required to abide by the AAS Anti-Harrassment Policy and the Guide to AAS Meeting Etiquette.
Accessibility: We are committed to making this symposium accessible to everybody. Please see the following link for more information: AAS 233 Accessibility.
Keynote
Andy Connolly, Department of Astronomy, University of Washington
The rise of the machines: LSST and the growth in machine learning
The development of a new generation of telescopes, large-scale detectors, and computational facilities has led to an era where it is now possible for deep optical surveys to image a large fraction of the visible sky. This growth in data has been coupled with the emergence of machine learning as a general tool for the analysis of astronomical data. In this talk I will look at the rise of survey astronomy over the last two decades and how analysis techniques have been adopted by the astronomical community to address the challenges of large and complex data sets. I’ll discuss why some techniques that, at first, appeared superior to existing applications did not gain traction in the astronomical community, and look at emerging methodologies that may impact astronomical surveys of the next decade such as the Large Synoptic Survey Telescope.
Panel - Faculty Applications, Interviews, and Negotiations
Julianne Dalcanton, Chair, Department of Astronomy, University of Washington
Julia Kamenetzky, Department of Physics, Westminster College
Kelle Cruz, Department of Physics and Astronomy, Hunter College; Founder of AstroBetter; CEO of ScienceBetter
Laura Lopez, Department of Astronomy, Ohio State University
BI Workshop
Lyndele von Schill, Director, NRAO Office of Diversity and Inclusion
This schedule is subject to change All times Pacific. Click on the speaker name for their professional biography. Click on the talk title to scroll down to the abstract.
Education: Supporting High Impact Undergraduate Research Experiences
Adam Beardsley
The HERA collaboration partners with the California Arizona Minority Partnership for Astronomy Research Education (CAMPARE) to create the CAMPARE-HERA Astronomy Minority Partnership (CHAMP) program. Each summer students participate in a one week radio astronomy crash course, nine weeks of research at a HERA member university, and an end-of-summer research symposium at Cal Poly Pomona. I will describe some details of the program, aspects that have worked well, lessons we have learned, and improvements we intend to make in future years. In addition to CHAMP, at Arizona State University we strive to involve our local undergraduates in research through a variety of opportunities. I will discuss some strategies, and how we integrated CHAMP students into our local cohort. I will also advertise the work of our students - some of whom are presenting posters at the AAS meeting.
Education: Discovering Resonant Phoenomena Through A.M. Radios and MKID Detectors
Kristina Davis
Throughout the nation, there is an urgent need to attract more students into STEM careers. The educational component of my NSF AAPF fellowship is to create a lesson module to teach students the underlying principle of taking direct images and spectra of exoplanets through constructing A.M. radio receivers. Not only are A.M. radio receivers simple circuits to construct, they are based on the same principles as MKID detectors, which are both resonant circuits. The lesson module broadly focuses on teaching resonant phenomenon, through the transfer of energy between sound, current, and light. The lesson will smoothly progress from resonance in sound waves on a guitar string, to sound waves travelling through a radio circuit, using resonance to tune the radio to a particular frequency, and finally arriving on using the detuning of a resonator circuit to measure incoming photons, the operational principle behind MKIDs.
My end result from this educational component will be to produce a series of video modules geared towards instructing teachers on how to present the lesson module to students. However, the videos addressing the basic concepts of resonance and their application to MKIDs and exoplanet imaging will be intended for a broad audience. Each video will be a 5-10 minute video teaching one specific area of the module so it is more digestible for beginners. The series will begin with teaching (at a high-school level) the physics of light and waves. From there it will shift to applying these principles to resonance. Students will be able to experience resonance in multiple ways that reinforce their understanding of physical principles involved. Students will be able to see a resonant wave on an oscilloscope attached to a guitar string, and then build their own A.M. radio from a kit provided by the instructors. The last part of the lesson will take the resonant properties of electronic circuits and apply them to photon-counting detectors, when a photon arrival de-tunes the resonator which can be measured with digital electronics. The lesson is designed to invoke deeper learning by having students practice taking a concept from one topic and applying it to a new concept.
Galaxies and Cosmology: Fast Fourier Transform Telescopes
Josh Dillon
21 cm cosmology is often cited for its enormous potential as a precise cosmological probe and test of Lambda-CDM, but realizing that potential requires building massive interferometers. While the cost of building large arrays scales roughly linearly with the number of antennas, the cost of the digital backend scales quadratically. Modern telescopes with hundreds of elements like the Hydrogen Epoch of Reionization Array already devote a significant fraction of their hardware budgets to computing. However, since all telescopes are Fourier transformers (and I'll explain what I mean by that), why not build a telescope that can take advantage of the FFT? In this talk, I will discuss the idea of fast Fourier transform telescopes as the next generation of 21 cm arrays and the instrumental, calibration, and analysis challenges they present.
Stars and Stellar Populations: The impact of companions on stellar rotational evolution
Stephanie T. Douglas
Observations of open clusters show that among stars of a given age, the rapid rotators tend to be binaries. This could be due to tidal effects acting over 0.01 – 10 billion years or interactions between the binary companion and the protoplanetary disk during the first 10 million years. Both effects would cause binary stars to rotate faster than single stars, thus altering angular momentum evolution in binary systems. I will discuss recent results about the relationship between rotation period and planet occurrence rate on binary orbital separation.
Galaxies and Cosmology: TIGlobular Clusters and Distances of Diffuse Galaxies in the Hyper Suprime-Cam SurveyLE
Johnny Greco
New generation optical imaging surveys are uncovering vast numbers of diffuse galaxies for which obtaining spectroscopic redshifts will be extremely difficult if not impossible. We investigate the use of globular cluster populations as a distance indicator for our new sample of very low surface brightness galaxies discovered with the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). The depth of HSC-SSP makes it sensitive to the peak of the globular cluster luminosity function (GCLF) out to distances of ~80 Mpc. Hence, using HSC-SSP imaging data alone, the GCLF should provide distance constraints for many of these galaxies, as well as insight into their formation histories and perhaps their dark matter halos. Our catalog of low surface brightness galaxies will ultimately grow to thousands of objects, which span galaxy morphologies, gas fractions, and halo environments. We will characterize the globular cluster populations for hundreds of these systems, using spectroscopic follow-up for a subset of objects to shed light on the utility of the GCLF as a distance indicator for diffuse galaxies in the LSST era.
Stars and Stellar Populations: APOGEE Chemical Abundances of the Large Magellanic Cloud
Sten Hasselquist
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) measures chemical abundances of 15+ chemical elements in some 300,000+ red giants stars across the entire Milky Way (MW). Recently, observations have extended to include ~2,500 stars residing in the Large Magellanic Cloud (LMC), resulting in the largest sample of LMC stars with individual abundances determined. From these data we are able to draw conclusions about the star formation history (SFH) of the LMC. Specifically, we find a high alpha-element plateau at [Fe/H] < -2.2 (lower than most MW dwarf galaxies), suggesting the LMC was relatively inefficient at converting gas to stars early on in its lifetime. However, we find that [Mg/Fe] and [O/Fe], two alpha-elements, correlate with [Fe/H] at [Fe/H] > -1.0, before anti-correlating at [Fe/H] > -0.5. We argue that this feature is a clear chemical sign of a star burst occurring in the LMC, as has previously been described by SFH studies of the LMC derived from CMDs. We fit parameterized chemical evolution models to the data to find that this star burst likely occurred some 2-3 Gyr ago, plausibly driven by a close interaction between the LMC and the SMC. Deficiencies in [Ni/Fe] and [Al/Fe] also support this theory.
Stars and Stellar Populations: Sub-subgiants in Gaia: New evidence for the impact of magnetic activity on stellar evolution from a population of cool, under-luminous giant stars
Emily Leiner
Sub-subgiant stars are found in both open and globular clusters fainter and/or redder than the giant branch, an area of the color-magnitude diagram (CMD) not occupied by standard stellar evolution tracks. Observations indicate that sub-subgiant stars share several characteristics: X-ray emission, photometric variability caused by large starspots, and where radial velocities are available, binary companions with orbits of 2-18 days. All these signs point to sub-subgiants as rapidly rotating, tidally-synchronized binaries with strong magnetic fields. Hypotheses for sub-subgiant formation include mass loss from a giant star during a dynamical encounter, Roche lobe overflow from a giant in a close binary, and inhibition of convection in a giant due to strong magnetic fields. Until now, sub-subgiants have been identified only in clusters where it is easy to see they do not fall on the isochrone. Here we present results from a search for sub-subgiants in the field. We use Gaia photometry and distances to precisely position a sample of field RS CVn binaries (magnetically active giants in short-period binaries) in the CMD. Our results show that many of these stars do fall in the sub-subgiant region, and that faster rotation periods correspond to redder and fainter sub-subgiants. This detection of field sub-subgiants illustrates that they are not dynamically-produced anomalies that form only in clusters; sub-subgiants are a normal phase in the evolution of close binary systems. We compare the CMD distribution of field sub-subgiants to theoretical models for binary mass transfer and magnetic inhibition of convection, and conclude that our results are more compatible with the magnetic models. If this is the case, sub-subgiants are a particularly dramatic example of the importance of rotation and magnetic activity in determining a star’s evolutionary path.
Stars and Stellar Populations: An Older, More Quiescent Universe from Panchromatic SED Fitting of the 3D-HST Survey
Joel Leja
Galaxy properties measured from broadband photometry tend to be either highly correlated, degenerate, or both. Therefore, the accuracy of basic properties like stellar masses and star formation rates (SFRs) depend on the accuracy of many second-order galaxy properties, including star formation histories (SFHs), stellar metallicities, dust properties, and many others. The high-dimensional models required for accurate measurements have been impossible until recently due to the substantial computational and statistical requirements. Now, we re-assess measurements of galaxy stellar masses and SFRs using a 14-parameter physical model build in the Prospector Bayesian inference framework. We find that galaxies are ~0.2 dex more massive and have ~0.2 dex lower star formation rates than classic measurements. These measurements lower the observed cosmic star formation rate density and increase the observed buildup of stellar mass, finally bringing these two metrics into agreement at the factor-of-two level at 1 < z < 3. I will also briefly introduce the Reverse Science Fair I hosted in Somerville, MA.
Planetary Systems: Exploring Planetary Systems in Research and the Classroom
Meredith MacGregor
In this talk, I will discuss some highlights from both my research and broader impact efforts this past year. M dwarfs are the most abundant stars in the galaxy and have a high frequency of Earth-sized planets, making them the favored targets of upcoming missions to detect and characterize exoplanets. Recently, I have detected large millimeter flares from the nearby M dwarf stars Proxima Centauri and AU Mic using ALMA. This work has opened a new window on the mechanisms responsible for stellar flares since the flaring properties of M dwarfs have not been well-studied at these wavelengths. To better constrain the properties of M dwarf flares and their impact on planetary habitability, I am currently undertaking a multi-wavelength monitoring campaign of Proxima Centauri involving many ground- and space-based facilities spanning radio to X-ray wavelengths. For my broader impact work, I will discuss my ongoing collaboration with the Carnegie Academy for Science Education (CASE), a program that aims to enhance the science, technology, engineering, and mathematics (STEM) education of students in the Washington, D.C. public school system through a range of programs designed to empower and educate both students and teachers. I have written and am now teaching a year-long curriculum for 6th-8th grade student as part of the First Light program (ongoing through the 2018-2019 school year). The curriculum is inspired by my own research and addresses three questions about astronomy: (1) What is space? (2) What other planets are like Earth? (3) How do we get to other planets?
Planetary Systems: NIRSPEC Upgrade for the Keck II Telescope
Emily Martin
NIRSPEC is a 1-5 micron echelle spectrometer in use on the Keck II telescope, capable of both medium (R~2000) and high (R~25,000) resolution observations. NIRSPEC was commissioned in 1999 and has since been a workhorse instrument at Keck for science topics ranging from the solar system to the most distant galaxies. In order to extend NIRSPEC’s lifetime, we have upgraded the instrument with new Teledyne H2RG detectors and replaced all transputer-based electronics with modern day motion and temperature controllers. These upgrades will improve NIRSPEC's efficiency and stability and hopefully keep it working for many years to come. I will present detailed updates on the major components of the upgrade, including the new spectrometer detector performance, the new slit-viewing camera optics and detector, and the increased stability of the internal mechanisms. Lastly, I will show early science results from the commissioning in December 2018.
From Black Holes to the ISM: Taking the temperature of the local interstellar medium
Claire Murray
A precise observational accounting for physical conditions of gas and dust in the Galactic interstellar medium (ISM) is vital both for correcting observations of extragalactic light and for resolving the bottleneck between mass reservoirs and star formation in galaxies. A key phase in the ISM lifecycle is occupied by neutral hydrogen (HI), whose temperature and density are crucial for understanding the formation of molecular cloud complexes from ambient neutral gas. However, multiphase HI properties mysterious, due to limited direct measurements of HI optical depth and uncertainty in how and whether this material can be traced by dust. I will present recent efforts to differentiate between distinct thermal HI phases using convolutional neural networks trained by synthetic spectra from numerical simulations. We validate the network using 100s of HI absorption measurements, finding excellent accuracy. With this model, we construct the highest-resolution all-sky map of optically thick HI in the local ISM using large-area 21cm emission observations from the GALFA-HI and the HI4Pi surveys. This map will characterize the structure of neutral gas envelopes to molecular clouds, and to improve dusty Galactic foreground estimation for extragalactic surveys.
Planetary Systems: Comparing Non-Redundant Masking and Kernel Phase for Direct Imaging of Exoplanets
Steph Sallum
Direct imaging has recently emerged as a viable planet detection and characterization method, with the potential to constrain masses, atmospheric compositions, and formation scenarios. Due to the limitations of adaptive optics and coronagraph performance, direct imaging has been most useful for detecting giant planets around nearby stars (~10 pc; where star-planet angular separations are large). Pushing to smaller semi-major axes and/or more distant target stars requires novel imaging techniques. The technique of non-redundant masking (NRM), which turns a filled aperture into an interferometric array, has expanded the planet detection parameter space within the diffraction limit. For high Strehl, the related kernel phase technique can achieve angular resolution comparable to NRM, without a dramatic decrease in throughput. I will compare NRM and kernel phase using real and simulated observations for ground- and spaced-based observing facilities. I will discuss the capabilities of both techniques for broadband detection and spectroscopic characterization of exoplanets.
From Black Holes to the ISM: Black Hole Spin Orientation in Microquasars
Greg Salvesen
The angular momentum, or spin, of a black hole has both magnitude and direction. While measurements of spin magnitude exist for a few dozen black holes, only a handful of spin direction measurements exist. Microquasars, which are black hole X-ray binaries with outflowing jets, offer an opportunity to probe the spin orientation because conventional theory predicts alignment between three axes of a microquasar system: the black hole spin axis, the jet axis, and the rotational axis of the inner accretion disk regions. However, these axes need not be aligned to the binary orbital axis. Applying a Markov chain Monte Carlo analysis to Swift/XRT observations of the microquasar GRO J1655–40, we find the data reject the binary orbital inclination as an imposed prior on the inner disk inclination. Instead, the data require a near edge-on disk inclination, which is consistent with the jet axis inclination. This is evidence for disk-jet alignment and provides independent confirmation of a misalignment between the angular momenta of the black hole and binary orbit in GRO J1655–40.
Education: Inspiring Curiosity with Soapboxes, Interactive Visualizations, and 3D Printing
Maria Weber
Why do you outreach? Each of us embark on our Broader Impacts projects with our own unique perspectives and goals. Ultimately, my goal is to inspire enquiry and impart a sense of curiosity within my audience, whatever the topic. I will discuss three new projects I have been involved in over the past year, in partnership with the University of Chicago and Adler Planetarium, designed to achieve these goals and more. The first project is Soapbox Science, an outreach platform that brings women scientists to city streets to engage in a discourse with the public about their research. Our first Chicagoland initiative received nearly 400 visitors and provided science communication training for twelve local early career women scientists. Working together with scientists at Adler Planetarium, the second project is an interactive web browser-based visualization that shows the orbit of a meteoroid within the solar system that crash landed in Lake Michigan in February 2017. Now referred to as the Aquarius Project, scientists and teens from the Chicago area are on a mission to retrieve fragments of this meteorite from the bottom of Lake Michigan. The final project called Touch the Universe pairs astrophysical visualizations with 3D printed objects to weave new multi-sensory narratives within Adler Planetarium’s Space Visualization Lab. All of our resources are made available via GitHub so that others may reproduce this program at their home institutions. I will also discuss the success and trials I have encountered while helping to launch these initiatives, and highlight how these projects have inspired curiosity within our audiences along the way.
Galaxies and Cosmology: The extragalactic universe according to JWST
Christina Williams
The James Webb Space Telescope (JWST) will be the premier infrared astronomical facility after its launch in 2021, and its extragalactic observations will revolutionize our understanding of galaxy evolution by breaking the redshift and sensitivity barriers of existing facilities. I will introduce the JWST Advanced Deep Extragalactic Survey (JADES), a joint program of the NIRCam and NIRSpec GTO teams that will be observed in JWST Cycle 1. The design of JADES relied heavily on mock catalogs that we produced using a novel phenomenological model for the evolution of galaxy properties across cosmic time. I will present our model designed for mock JWST observations, and show its science predictions out to z~15 for the JADES survey, including the rest-frame UV galaxy counts beyond the current redshift frontier (z>10), the emergence of the first quenched galaxies at z>4, and constraints on the ionization properties and ISM of early galaxies at 4<z<9. The JWST mock data products are publicly available to facilitate GO Cycle 1 proposal planning, and will serve as a powerful future JWST data analysis tool after launch.