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.

The interaction between galaxies is believed to be the main origin of the peculiarities of galaxies, which disturbs not only the morphology but also their kinematics. These disturbed and asymmetric features are the indicators of galaxy interaction. We study the velocity field of the ionized gas of the paired galaxies in the SDSS-IV MaNGA IFU survey. Using the kinemetry package, we fit the velocity field of the ionized gas to quantify the degree of kinematic asymmetry. We find that the star formation rate (SFR) of the paired galaxies with high kinematic asymmetry is significantly enhanced even when the projected separation between the pair members is quite large (d p ∼ 100 h −1 kpc). On the contrary, no significant SFR enhancement is found for the paired galaxies with low kinematic asymmetry even when their projected separation is small (d p < 30 h −1 kpc). Moreover, we also find that the fraction of galaxies with high kinematic asymmetry is much higher in close pairs (d p < 30 h −1 kpc) than those with larger d p , which explains well the early statistical finding of the significant SFR enhancement in close pairs. Our new findings illustrate that the kinematic asymmetry is an excellent indicator of galaxy-galaxy interaction strength, which helps us better understand the merging stage of the observed galaxy pairs.

We measure the bivariate luminosity function (BLF) of galaxy pairs and use it to probe and characterize the galaxy-galaxy interaction between pair members. The galaxy pair sample is selected from the main galaxy sample of Sloan Digital Sky Survey and supplied with a significant number of redshifts from the LAMOST spectral and GAMA surveys. We find the BLFs depend on the projected distance d p between pair members. At large separation d p > 150 h −1 kpc, the BLF degenerates into a luminosity function (LF) of single galaxies, indicating few interactions between pair members. At 100 h −1 kpc ≤ d p ≤ 150 h −1 kpc, the BLF starts to show the correlation between pair members, in the sense that the shape of the conditional luminosity function (CLF) of one member galaxy starts to depend on the luminosity of the other member galaxy. Specifically, the CLF with a brighter companion has a steeper faint-end slope, which becomes even more significant at 50 h −1 kpc ≤ d p ≤ 100 h −1 kpc. This behavior is consistent with the scenario, and also is the observational evidence, that dynamic friction drives massive major merger pairs to merge more quickly. At close distance d p ≤ 50 h −1 kpc, besides the merging time-scale effect, the BLF also shows an overall brightening of ∆M r ≥ 0.04 mag, which reveals the enhanced star formation of the close-pair phase. By combining another statistical conclusion that the star formation rate of late-type galaxies in close pairs is enhanced at a level of about 40%, we further conclude that the average starburst time-scale of close pairs is as long as 0.4 Gyr.