The Sloan Digital Sky Survey (SDSS) is one of the Sloan Foundation’s longest running basic science programs, with a nearly 25-year period of continuous observation shedding light on some of the most important questions in astronomy and astrophysics. The fifth phase of the Sloan Digital Sky Survey (SDSS-V) consists of an all-sky, multi-epoch spectroscopic survey observing the universe in both the visible and the infrared portion of the spectrum. SDSS-V will observe the entire sky using two complementary telescopes—one at Apache Point Observatory in New Mexico and a second at Las Campanas Observatory in Chile—allowing it to map the night sky more fully, with the Chilean telescope able to observe core parts of the Milky Way not visible in the Northern Hemisphere. Grant funds will allow SDSS-V to conduct its originally planned, full five-year observation program and observe multiple objects, at multiple distances, across three constituent sub-surveys: the Milky Way Mapper, which will study the history of our own galaxy; the Black Hole Mapper, which will observe the behavior of supermassive blackholes that sit at the center of galaxies; and the Local Volume Mapper, which will examine the interstellar medium in key regions of the Milky Way and other galaxies. This grant will allow SDSS-V to complete the upgrade to a new robotic focal plane observation system, complete the construction of the Local Volume Mapper instrumentation hardware, and extend the SDSS-V observation period to 2026-2027.

In 2015, the Sloan Digital Sky Survey established a Faculty and Student Team (FAST) program to improve on the low numbers of underrepresented minorities (URMs) both in the SDSS collaboration itself and in astronomy as a whole. The FAST program introduces clusters of faculty and students (mainly URMs) from non-SDSS-participating universities into the collaboration, usually with one faculty member supervising anywhere from one to three undergraduates or one graduate student. These faculty-student teams are then paired with mentors from the SDSS collaboration to help them become full members of the collaboration. To date, institutions sending FAST teams to SDSS include DePaul University, New Mexico State, University of California San Diego, Texas Tech, and two from City University of New York (Hunter College and Staten Island). Funds from this grant will allow the addition of three new FAST teams to the project, each completing a three-year term. Each FAST team faculty lead receives salary support for approximately one summer month in their first year of participation, and students on each team receive financial support through the entire period of FAST program participation. A dedicated SDSS FAST science liaison oversees the day-to-day operation of the program.

This grant provides partial support for the planning and implementation of the fifth research phase of the Sloan Digital Sky Survey (SDSS-V). The five-year project aims to use two telescopes (one in New Mexico and one in Chile) fitted with state of the art spectroscopic instruments to answer fundamental questions in astronomy, astrophysics, and cosmology about the forces shaping the origin, structure, and future of galaxies; the nature of supermassive black holes; and how regions between stars and galaxies, known as the interstellar medium, impact how these celestial objects form and grow. SDSS-V will be the most extensive spectroscopic observatory program in operation through the middle of the next decade. Over the course of five years, it will collect infrared spectra of over six million stars in the Milky Way (an order of magnitude more than have ever been observed), optical spectra of over 400,000 black holes, and over 25 million optical spectra of interstellar gas. As with previous phases, all data collected by SDSS-V will be released to both the scientific community and the general public under open principles, allowing non-affiliated scientists and stargazers alike to partake in SDSS discoveries. Planned technological improvements to the SDSS telescopes will make it one of the only observation programs capable of enhancing, complementing, and making the best use of data from other large astronomical surveys. Both SDSS-V telescopes will be equipped with rapidly reconfigurable fiber positioning technologies that will reduce the time it takes to collect object spectra from hours down to minutes. This will allow the SDSS to rapidly shift its focus and observe interstellar phenomena identified by the Large Synoptic Survey Telescope, the Kepler and TESS space missions, the Gaia space mission, and the eROSITA satellite. This grant provides approximately 25 percent of the total SDSS-V project budget and includes funds for project infrastructure and planning, research, instrumentation and technology development, and outreach and education. The remainder of funds will be raised from within the scientific community.

The SDSS data management structure, software, and interface has been on the frontier of astronomy since it was developed in the early 2000s. Many leading astronomical data centers use, integrate, and rely heavily on SDSS data, and these data are routinely accessed by amateur astronomers, students, and the public. This grant provides support to upgrade two back-end components of the SDSS data archive. The first is the Science Archive Server (SAS), housed at the University of Utah. SAS includes SDSS’s raw and calibrated images, and the SDSS spectrum files, all of which are primarily used by professional astronomers. The second is the Catalog Archive Server (CAS), hosted at Johns Hopkins University. CAS contains the primary catalog data and all metadata extracted from the raw images and spectra. CAS helps to facilitate research from astronomers both within and outside of the collaboration, as it serves as the primary link between SDSS data and other data sets in astronomy. In addition to modernizing and expanding the core functioning of these two systems, the upgrades will help improve the integration of SDSS data with broader outreach and public education efforts, including better connections with SDSS Voyages, the newly developed web portal devoted to public engagement.

Funds from this grant support two projects that aim to increase the participation of underrepresented minority (URM) students in the Sloan Digital Sky Survey collaboration. The first, the Faculty and Student Team (FAST) program creates research teams led by a faculty member and comprised of at least one URM graduate student and/or two to three advanced URM undergraduate students. Each FAST unit (faculty and students) is subsequently linked with a research team at a formal SDSS participating institution; the research team will help integrate them into the collaboration, providing a kind of double mentoring system: the SDSS institution mentors the URM FAST team, and the faculty lead mentors the participating URM students on the team. The goal is to provide these URM students with training and guidance within SDSS, anticipating that they will eventually transition to an astronomy Ph.D. program at an SDSS member university.  The second supported project is a distributed summer program that will provide research experiences for minority undergraduates. The 10-week program, to be run by New Mexico State University, will bring interested URM students from non-SDSS institutions to the home institution of SDSS researchers to facilitate one-on-one mentoring and exposure to the global SDSS collaboration. In addition to their direct SDSS mentor, students would have regular virtual check-ins with the other participants, an in-person kick-off meeting, and a culminating research meeting, likely held in conjunction with a formal SDSS collaboration meeting. Over time, the FAST and summer research programs have the potential to increase the participation of underrepresented minority doctoral students in astronomy programs nationwide.

This grant provides support for the construction, installation, and deployment of an infrared spectrograph for use by the Sloan Digital Sky Survey (SDSS) to study star formation in the Milky Way.  The instrument, to be installed on the du Pont Telescope in Las Campanas, Chile, is identical to one already constructed and installed on the Sloan Telescope at Apache Point Observatory in New Mexico, the SDSS’s primary observational instrument.  The new spectrograph, installed in the southern hemisphere, will allow SDSS researchers, working in collaboration with their Chilean colleagues, to make parallel observations both north and south of the equator, quadrupling the number of observable stars and exposing sections of the inner Milky Way unviewable from the north.  The project also promises to be a productive collaboration between American and Chilean astronomers, with nearly 20 Chilean scientists and engineers from multiple institutions directly involved in the installation and operation of the instrument.

This grant funds a fourth phase of the Sloan Digital Sky Survey (SDSS IV), a pioneering astronomical survey that utilizes a 2.5 meter optical telescope at Apache Point Observatory near Cloudcroft, New Mexico. Over the next six years, SDSS IV will pursue three innovative projects that seek to answer key questions in astronomy and astrophysics. The first project, APOGEE-2, will decipher the history of the growth of the Milky Way's stellar halo; precisely measure the mass of the Milky Way; determine the stellar structure around the galactic center; find stellar companions such as planets, white dwarfs and neutrons stars; and determine stellar masses, ages, and elemental abundances with unprecedented precision. The second, MaNGA will study 6,700 nearby galaxies and measure their dynamics, growth histories, and chemical abundances as a function of their mass, type, environment, and other controlling variables. The third, eBOSS, will measure the expansion of the universe over the past 12 billion years using baryonic acoustic oscillation, the most accurate absolute distance measurement technique known, and filling a gap in current measurements of galaxies between about 6.5 and 11 billion light?years away. eBoss will provide the fullest understanding yet of the so-called "dark energy" that is causing the expansion of the universe to accelerate. As in previous phases of the projects, all SDSS data will be publically released through the internet, enabling astronomers and astrophysicists all over the world to use the data for their own research.