This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.

We introduce the Swift/UVOT+MaNGA (SwiM) value-added catalog, which comprises 150 galaxies that have both Sloan Digital Sky Survey (SDSS)/MaNGA integral field spectroscopy and archival Swift/UVOT near-UV (NUV) images. The similar angular resolution between the three Swift/UVOT NUV images and the MaNGA maps allows for a high-resolution comparison of optical and NUV indicators of star formation, crucial for constraining quenching and attenuation in the local universe. The UVOT NUV images, SDSS images, and MaNGA emission line and spectral index maps have all been spatially matched and reprojected to match the point-spread function (PSF) and pixel sampling of the Swift/UVOT uvw2 images and are presented in the same coordinate system for each galaxy. The spectral index maps use the definition first adopted by Burstein et al., which makes it more convenient for users to compute spectral indices when binning the maps. Spatial covariance is properly taken into account in propagating the uncertainties. We also provide a catalog that includes PSF-matched aperture photometry in the SDSS optical and Swift NUV bands. In an earlier companion paper, we used a subset of these galaxies to explore the attenuation laws of kiloparsec-sized star-forming regions. The catalog, maps for each galaxy, and associated data models are publicly available on the SDSS website.

The attenuation of light in star forming galaxies is correlated with a multitude of physical parameters including star formation rate, metallicity and total dust content. This variation in attenuation is even more prevalent on the kiloparsec scale, which is relevant to many current spectroscopic integral field unit surveys. To understand the cause of this variation, we present and analyse Swift/UVOT near-UV (NUV) images and SDSS/MaNGA emission-line maps of 29 nearby (z < 0.084) star forming galaxies. We resolve kiloparsec-sized star forming regions within the galaxies and compare their optical nebular attenuation (i.e., the Balmer emission line optical depth, τ l B ≡ τ Hβ − τ Hα ) and NUV stellar continuum attenuation (via the NUV power-law index, β) to the attenuation law described by Battisti et al. The data agree with that model, albeit with significant scatter. We explore the dependence of the scatter of the β-τ l B measurements from the star forming regions on different physical parameters, including distance from the nucleus, star formation rate and total dust content. Finally, we compare the measured τ l B and β between the individual star forming regions and the integrated galaxy light. We find a strong variation in β between the kiloparsec scale and the larger galaxy scale not seen in τ l B . We conclude that the sight-line dependence of UV attenuation and the reddening of β due to the light from older stellar populations could contribute to the β-τ l B discrepancy.