14 January 2020

Sloan Digital Sky Survey Offers New Membership Incentive: TESS, eROSITA, and More

Keivan Stassun, Vanderbilt University

SDSS LogoWith the recent approval of a TESS Extended Mission and the successful launch of eROSITA, the Sloan Digital Sky Survey (SDSS) is offering a limited-time membership incentive: SDSS-V Plus. The Sloan Digital Sky Survey V (SDSS-V) project comprises three all-sky observing programs — Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper — set to operate from 2020 to 2025. The project has been designed for maximum overlap with NASA’s Transiting Exoplanet Survey Satellite (TESS) and the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) mission.

SDSS-V Plus not only offers full access to the proprietary data that will be collected in the coming years, but also immediate access to proprietary data already in hand for tens of thousands of TESS and eROSITA sources. Beyond TESS and eROSITA science, this immediate access also includes the proprietary integral field unit spectroscopy of ~10,000 nearby galaxies. This incentive may be of particular interest to scientists at institutions that do not otherwise enjoy privileged access to facilities for spectroscopic followup of TESS/eROSITA sources and/or resolved spectroscopy of galaxies. 

Stellar Astrophysics and Exoplanet Science with TESS

A specific goal of SDSS-V is to deliver high-level spectroscopic properties for several hundred thousand stars in the TESS footprint, in both the northern and southern celestial hemispheres. Leveraging the SDSS all-sky APOGEE spectrographs’ proven data quality and processing pipeline, spectroscopic properties to be delivered include effective temperatures, surface gravities, bulk metallicities, detailed chemical abundances for up to 15 elements, as well as multi-epoch radial velocities for a subset of targets. Coverage will include the entire TESS sky, and the TESS continuous viewing zones (CVZs) will be especially intensively observed. 

The recent announcement by NASA that the TESS mission will be extended through at least 2022 — and the potential for additional extensions beyond that time — provides even greater excitement for discovery in the areas of stellar astrophysics and solar system architectures, enabled by the unique combination of TESS light curves and detailed spectroscopic properties from SDSS. 

Specific TESS-related targeting classes for SDSS-V include candidate exoplanet hosts (including all ~300,000 TESS 2-minute cadence targets in both the northern and southern continuous viewing zones); red giant stars with measurable seismic and/or granulation variations and for which precise ages will be derived (including ~250,000 stars that will have TESS light curves spanning at least 80 days); massive stars with convective cores (including ~1,500 stars with measurable seismic variations); and thousands of eclipsing binaries for fundamental stellar astrophysics. In anticipation of the great synergies between SDSS-V and TESS, a pathfinder program was initiated in 2017 that has already amassed more than 15,500 single-epoch spectra of TESS CVZ targets. SDSS-V Plus members will enjoy privileged access to these data immediately. 

AGN/Extragalactic Science with eROSITA

SDSS-V’s Black Hole Mapper (BHM) program will obtain spectra for more than a half million black holes over the full mass range from stellar to supermassive. One of the primary foci of the BHM is the follow-up of the newly launched eROSITA satellite mission. With its high sensitivity and large field of view, eROSITA will discover as many new X-ray sources in its first 12 months as are known today, after more than 50 years of X-ray astronomy! SDSS-V has a dedicated program to follow up these sources and exploit the multi-wavelength coverage of these systems.

In anticipation of the great synergies between SDSS and eROSITA, a pathfinder program called SPIDERS (SPectroscopic IDentification of ERosita Sources) was initiated in 2014 that has already amassed more than 33,000 spectra of expected eROSITA targets. Of these, some 5,000 are candidate AGN, the remainder being cluster galaxies. SDSS-V Plus members will enjoy privileged access to these pathfinder data immediately, as well as additional pathfinder data that are planned for early 2020 of ~10,000 targets in the eROSITA performance verification field (eROSITA field GAMA09). 

Whom to Contact 

As with past SDSS survey programs, all SDSS data products will enter the public domain by the end of the SDSS program (nominally set for 2025). Only SDSS-V members enjoy immediate access to these data as they are collected, beginning in 2020. In addition, members benefit from collaboration with the many other scientists across the SDSS-V consortium, leading to opportunities for participation on a large array of projects that exploit the unique strengths of SDSS-V data. Although broad parameters of the SDSS-V program are defined, members who join now will have the opportunity to shape decisions about target selection and survey design. Institutional membership in the SDSS-V consortium provides invaluable opportunities for students, postdocs, and early career faculty to participate at every level in a highly interactive international collaboration.

General enquiries on how to join SDSS-V can be addressed to its director, Juna Kollmeier. Specific questions pertaining to the TESS opportunity can be directed to SDSS-V executive committee members Keivan Stassun and/or Conny Aerts. Specific questions pertaining to the e-ROSITA opportunity can be directed to SDSS-V executive committee members Meg Urry, John Mulchaey, and/or Don Schneider

Cost to Join 

SDSS-V Plus membership is $255,000 per individual member (and their students); five or more individual memberships confers membership to your entire institution. If you are already a member of SDSS-V, you can upgrade your membership for $25,000 per individual ($125,000 per institution) to SDSS-V Plus.