2019 TDA Focuses on TESS, ZTF, and Gaia Data
The fourth-annual Scialog: Time Domain Astrophysics (TDA) conference was held May 9-12 in Tucson, Ariz., with 47 Scialog Fellows and eight discussion facilitators attending, as well as representatives from the conference co-sponsors, the Heising-Simons Foundation and Research Corporation for Science Advancement (RCSA), and from The Kavli Foundation, which provided additional support for the conference.
“Scialogs are different than your normal conference.” RCSA President Dan Linzer told the participants. “For the Fellows, the focus here is on your voice and your very active participation throughout the meeting. You will not be sitting back, just listening to a series of presentations on completed studies. Instead, you will be engaged throughout these three days in pushing the boundaries of the field.”
The unique Scialog format limits formal presentations and devotes the vast majority of the conference to small breakout discussions to identify risky blue-sky ideas for new lines of research and form new collaborative interdisciplinary teams to pursue these ideas. Significant meeting time is devoted to “on-the-spot” writing of proposals to provide seed funding for collaborative teams newly formed at the meeting.
Scialog Fellows at the 2019 Scialog: TDA conference produced 27 team proposals on advanced topics in stellar and galactic astrophysics. RCSA Senior Program Director Richard Wiener said the high quality of proposed projects promises to make selection of five to seven projects for funding very challenging. The Scialog Advisory Committee will be making funding recommendations in June.
The first two TDA conferences focused on stars and explosions, and the third dealt with the 2018 data release of Gaia’s 3D census of the Milky Way Galaxy. Gaia is an ambitious mission to chart a three-dimensional map of our galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy.
Regarding the fourth Scialog: TDA conference, Wiener said, “Contemporaneous data releases from Gaia, TESS and ZTF over the past year provide a tremendous opportunity to open new research horizons with cutting-edge questions being addressed by data from one or several of these recent surveys.” TESS is the Transiting Exoplanet Survey Satellite, a space telescope for NASA's Explorers program, designed to search for exoplanets; ZTF, the Zwicky Transient Facility, is a sky-survey telescope based at California’s Palomar Observatory. TESS has led to the discovery of thousands of new objects in the universe, from asteroids and exoplanets to black holes and other phenomena.
The first ZTF Public Data Release intentionally coincided with the beginning of the 2019 Scialog: TDA conference. The products include ~3.4 million single-exposure images, ~102 thousand co-added images, accompanying source catalog files containing ~63 billion sources detected from those images, and ~2 billion lightcurves constructed from the single-exposure extractions.
The over-arching purpose of Scialog: TDA has been to bring together theorists, observers and computational scientists to identify critical lines of inquiry needed to exploit current synoptic optical surveys and set the stage to maximize the benefit of new facilities, such as the Large Synoptic Survey Telescope (LSST) to be commissioned by 2022.
Keynote speakers at this latest conference included Thomas Barclay, NASA Goddard Space Flight Center and the University of Maryland - Baltimore County, and Kathryn Johnston, Columbia University.
Barclay noted that over the next two years TESS will observe most of the sky for at least a month at a time, collecting continuous 30-min cadence photometry.
“The primary science goal of the mission is to detect transiting exoplanets that can be characterized by larger ground and space-based telescopes,” he said.
In addition, primarily due to its large 96x24 degree field of view, the TESS dataset provides an incredible resource that can be mined by myriad astronomical fields, Barclay added. He predicted TESS will be capable of discovering approximately 1,400 previously unknown near earth objects in its full-frame images, as well as detecting oscillations from more than a million red giant stars.
“The value of TESS data can be significantly increased when combined with game-changing surveys like Gaia, or simultaneous ground and space-based observations that provide multi-wavelength data,” he said. “With TESS capable of lasting for a decade or more, and plans to decrease the observing cadence to 10 minutes, there is much to look forward to.”
Johnston shared her thoughts on the revolutions in our understanding of the Milky Way that have been enabled by large stellar surveys over the past decade and summed up the spectacular science results in the last year from analyses of Gaia, Data Release 2, by groups across the globe.
She also discussed how scientists can more effectively coordinate with different sets of expertise (e.g. data analysis, theory, simulations) and balance the natural tensions between teamwork and competition in dealing with the floods of astronomical data scientists now face.
The conference’s senior discussion facilitators included Barclay and Johnston as well as Lars Bildsten, University of California, Santa Barbara; Boris Gaensicke, University of Warwick; Suzanne Hawley, University of Washington; Juna Kollmeier, Carnegie Institution for Science; Shri Kulkarni, California Institute of Technology; and Jeno Sokoloski, Columbia University and Director of Science at LSST Corporation.
