An updated cool dwarf catalog for the transiting exoplanet survey satellite using Gaia DR2

An undergrad mentee of mine presented results at the meeting in a poster. I am a co-author of the presentation. The abstract is available on ADS: https://ui.adsabs.harvard.edu/abs/2019AAS...23314001C/abstractWe present an updated catalog of cool dwarf stars for the recently launched Transiting Exoplanet Survey Satellite (TESS) for the purpose of selecting targets for two-minute cadence observations. At launch, TESS was provided a similar catalog of cool dwarfs whose stellar parameters were approximated using proper motions and — where they existed — archival parallax measurements. Most targets therefore have significant uncertainties. Now, with the highly anticipated Gaia DR2 parallax measurements released in April 2018, we updated stellar parameters where we are able to determine a cross-match with confidence, as well as determined new targets from a cross-match between Gaia and 2MASS. We anticipate delivery to TESS by the end of 2018, at which point it will have completed about one fourth of its mission. With the updated catalog, we hope that TESS will discover Earth-sized and sub-Earth-sized exoplanets around late K and M-dwarf type stars with a higher planet yield. This project was supported in part by the NSF REU grant AST-1757321 and by the Nantucket Maria Mitchell Association.Published versio

The Revised TESS Input Catalog and Candidate Target List

We describe the catalogs assembled and the algorithms used to populate the revised TESS Input Catalog (TIC), based on the incorporation of the Gaia second data release. We also describe a revised ranking system for prioritizing stars for 2-minute cadence observations, and assemble a revised Candidate Target List (CTL) using that ranking. The TIC is available on the Mikulski Archive for Space Telescopes (MAST) server, and an enhanced CTL is available through the Filtergraph data visualization portal system at the URL http://filtergraph.vanderbilt.edu/tess_ctl.Comment: 30 pages, 16 figures, submitted to AAS Journals; provided to the community in advance of publication in conjunction with public release of the TIC/CTL on 28 May 201

Disentangling the Cosmic Web toward FRB 190608

FRB 190608 was detected by ASKAP and localized to a spiral galaxy at $z_{host}=0.11778$ in the SDSS footprint. The burst has a large dispersion measure ($DM_{FRB}=339.8$ $pc/cm^3$) compared to the expected cosmic average at its redshift. It also has a large rotation measure ($RM_{FRB}=353$ $rad/m^2$) and scattering timescale ($\tau=3.3$ $ms$ at $1.28$ $GHz$). Chittidi et al (2020) perform a detailed analysis of the ultraviolet and optical emission of the host galaxy and estimate the host DM contribution to be $110\pm 37$ $pc/cm^3$. This work complements theirs and reports the analysis of the optical data of galaxies in the foreground of FRB 190608 to explore their contributions to the FRB signal. Together, the two manuscripts delineate an observationally driven, end-to-end study of matter distribution along an FRB sightline; the first study of its kind. Combining KCWI observations and public SDSS data, we estimate the expected cosmic dispersion measure $DM_{cosmic}$ along the sightline to FRB 190608. We first estimate the contribution of hot, ionized gas in intervening virialized halos ($DM_{halos} \approx 7-28$ $pc/cm^3$). Then, using the Monte Carlo Physarum Machine (MCPM) methodology, we produce a 3D map of ionized gas in cosmic web filaments and compute the DM contribution from matter outside halos ($DM_{IGM} \approx 91-126$ $pc/cm^3$). This implies a greater fraction of ionized gas along this sightline is extant outside virialized halos. We also investigate whether the intervening halos can account for the large FRB rotation measure and pulse width and conclude that it is implausible. Both the pulse broadening and the large Faraday rotation likely arise from the progenitor environment or the host galaxy