Abstract We present the H i-MaNGA programme of H i follow-up for the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. MaNGA, which is part of the Fourth phase of the Sloan Digital Sky Surveys, is in the process of obtaining integral field unit spectroscopy for a sample of ∼10 000 nearby galaxies. We give an overview of the H i 21cm radio follow-up observing plans and progress and present data for the first 331 galaxies observed in the 2016 observing season at the Robert C. Bryd Green Bank Telescope. We also provide a cross-match of the current MaNGA (DR15) sample with publicly available H i data from the Arecibo Legacy Fast Arecibo L-band Feed Array survey. The addition of H i data to the MaNGA data set will strengthen the survey’s ability to address several of its key science goals that relate to the gas content of galaxies, while also increasing the legacy of this survey for all extragalactic science.

Supermassive Black Holes (BHs) residing in brightest cluster galaxies (BCGs) are overly massive when considering the local relationships between the BH mass and stellar bulge mass or velocity dispersion. Due to the location of these BHs within the cluster, large-scale cluster processes may aid the growth of BHs in BCGs. In this work, we study a sample of 71 galaxy clusters to explore the relationship between the BH mass, stellar bulge mass of the BCG, and the total gravitating mass of the host clusters. Due to difficulties in obtaining dynamically measured BH masses in distant galaxies, we use the Fundamental Plane relationship of BHs to infer their masses. We utilize X-ray observations taken by Chandra to measure the temperature of the intra-cluster medium (ICM), which is a proxy for the total mass of the cluster. We analyze the M BH − kT and M BH − M bulge relationships and establish the best-fitting power laws:log 10 (M BH /10 9 M ) = −0.35 + 2.08 log 10 (kT /1keV) and log 10 (M BH /10 9 M ) = −1.09 + 1.92 log 10 (M bulge /10 11 M ). Both relations are comparable with that established earlier for a sample of brightest group/cluster galaxies with dynamically measured BH masses. Although both the M BH − kT and the M BH − M bulge relationships exhibit large intrinsic scatter, based on Monte Carlo simulations we conclude that dominant fraction of the scatter originates from the Fundamental Plane relationship. We split the sample into cool core and non-cool core resembling clusters, but do not find statistically significant differences in the M BH − kT relation. We speculate that the overly massive BHs in BCGs may be due to frequent mergers and cool gas inflows onto the cluster center.

Aims. We aim to conduct an assessment of the demographics of substructures in cosmological simulations to identify low-mass stellar systems at high redshift, with a particular focus on globular cluster (GC) candidates. Methods. We explored a suite of high-resolution cosmological simulations from the First Billion Years Project (FiBY) at z ≥ 6. All substructures within the simulations have been identified with the SUBFIND algorithm. From our analysis, two distinct groups of objects emerge. We hypothesise that the substructures in the first group, which appear to have a high baryon fraction (fb ≥ 0.95), are possible infant GC candidates. Objects belonging to the second group have a high stellar fraction (f* ≥ 0.95) and show a potential resemblance to infant ultra-faint dwarf galaxies. Results. The high baryon fraction objects identified in this study are characterised by a stellar content similar to the one observed in present-day GCs, but they still contain a high gas fraction (fgas ∼ 0.95) and a relatively low amount of dark matter. They are compact systems, with densities higher than the average population of FiBY systems at the same stellar mass. Their sizes are consistent with recent estimates based on the first observations of possible proto-GCs at high redshifts. These types of infant GC candidates appear to be more massive and more abundant in massive host galaxies, indicating that the assembly of galaxies via mergers may play an important role in building several GC-host scaling relations. Specifically, we express the relation between the mass of the most massive infant GC and its host stellar mass as log(Mcl) = (0.31 ± 0.15) log (M*, gal + (4.17 ± 1.06). We also report a new relation between the most massive infant GC and the parent specific star formation rate of the form log(Mcl) = (0.85 ± 0.30) log (sSFR)+α that describes the data at both low and high redshift. Finally, we assess the present-day GC mass (GC number) – halo mass relation offers a satisfactory description of the behaviour of our infant GC candidates at high redshift, suggesting that such a relation may be set at formation.