We describe the Sloan

This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2); new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library “MaStar”). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).

The fourth generation of the Sloan

The fourth generation of the Sloan

No abstract

We report the characterization of the first 62 MaNGA Active Galactic Nuclei (AGN) hosts in the Fifth Product Launch (MPL-5) and the definition of a control sample of non-active galaxies. This control sample -comprising two galaxies for each AGNwas selected in order to match the AGN hosts in terms of stellar mass, redshift, visual morphology and inclination. The stellar masses are in the range 9.4 < log (M/M ) < 11.5, and most objects have redshifts ≤ 0.08. The AGN sample is mostly comprised of low-luminosity AGN, with only 17 nuclei with L([OIII]λ 5007) ≥ 3.8 × 10 40 erg s −1 (that we call "strong AGN"). The stellar population of the control sample galaxies within the inner 1-3 kpc is dominated by the old (∼ 4 -13 Gyr) age component, with a small contribution of intermediate age (∼640-940 Myr) and young stars (≤ 40 Myr) to the total light at 5700Å. While the weaker AGN show a similar age distribution to that of the control galaxies, the strong AGN show an increased contribution of younger stars and a decreased contribution of older stars. Examining the relationship between the AGN stellar population properties and L([OIII]), we find that with increasing L([OIII]), the AGN exhibit a decreasing contribution from the oldest (>4 Gyr) stellar population relative to control galaxies, but have an increasing contribution from the younger components with ages ∼40 Myr. We also find a correlation of the mean age differences (AGN -control) with L([OIII]), in the sense that more luminous AGN are younger than the control objects, while the low-luminosity AGN seem to be older. These results support a connection between the growth of the galaxy bulge via formation of new stars and the growth of the Supermassive Black Hole via matter accretion in the AGN phase.

We present spatially resolved stellar population (SP) age maps, average radial profiles and gradients for the first 62 active galactic nuclei (AGN) observed with Sloan Digital Sky Survey (SDSS)-IV Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) to study the effects of the active nuclei on the star formation history of the host galaxies. These results, derived using the STARLIGHT code, are compared with a control sample of non-active galaxies matching the properties of the AGN hosts. We find that the fraction of young SPs in highluminosity AGN is higher in the inner (R ≤ 0.5 R e) regions when compared with the control sample; low-luminosity AGN, on the other hand, present very similar fractions of young stars to the control sample hosts for the entire studied range (1 R e). The fraction of intermediate-age SP of the AGN hosts increases outwards, with a clear enhancement when compared with the control sample. The inner region of the galaxies (AGN and control galaxies) presents a dominant old SP, whose fraction decreases outwards. We also compare our results (differences between AGN and control galaxies) for the early-and late-type hosts and find no significant differences. In summary, our results suggest that the most luminous AGN seems to have been triggered by a recent supply of gas that has also triggered recent star formation (t ≤ 40 Myr) in the central region.

We investigate the effects of Active Galactic Nuclei (AGN) on the gas kinematics of their host galaxies, using MaNGA data for a sample of 62 AGN hosts and 109 control galaxies (inactive galaxies). We compare orientation of the line of nodes (kinematic Position Angle -PA) measured from the gas and stellar velocity fields for the two samples. We found that AGN hosts and control galaxies display similar kinematic PA offsets between gas and stars. However, we note that AGN have larger fractional velocity dispersion σ differences between gas and stars [σ frac = (σ gas − σ stars )/σ stars ] when compared to their controls, as obtained from the velocity dispersion values of the central (nuclear) pixel (2. ′′ 5 diameter). The AGN have a median value of σ frac of < σ frac > AGN = 0.04, while the the median value for the control galaxies is < σ frac > CTR = −0.23. 75 % of the AGN show σ frac > −0.13, while 75 % of the normal galaxies show σ frac < −0.04, thus we suggest that the parameter σ frac can be used as an indicative of AGN activity. We find a correlation between the [O ]λ5007 luminosity and σ frac for our sample. Our main conclusion is that the AGN already observed with MaNGA are not powerful enough to produce important outflows at galactic scales, but at 1-2 kpc scales, AGN feedback signatures are always present on their host galaxies.