Analyzing a sample of 84 early-type galaxies (ETGs) with directly measured supermassive black hole massesnearly doubling the sample size of such galaxies with multicomponent decompositions-a symmetric linear regression on the reduced (merger-free) sample of 76 galaxies reveals M M BH ,sph 1.27 0.07 * µ  with a total scatter of Δ rms =0.52dex in the M log BH ( ) direction. Importantly, however, we discover that the ES/S0-type galaxies with disks are offset from the E-type galaxies by more than a factor of ten in their M M BH ,sph * ratio, with ramifications for formation theories, simulations, and some virial factor measurements used to convert AGN virial masses into M BH . Separately, each population follows a steeper relation with slopes of 1.86±0.20 and 1.90±0.20, respectively. The offset mass ratio is mainly due to the exclusion of the disk mass, with the two populations offset by only a factor of two in their M M BH ,gal * ratio in the M BH -M ,gal * diagram where M M BH ,gal 1.8 0.2 * µ  and 0.6 0.1 rms D =  dex depending on the sample. For M M 10 BH 7  , we detect no significant bend nor offset in either the M BH -M ,sph * or M BH -M ,gal * relations due to barred versus non-barred, or core-Sérsic versus Sérsic, ETGs. For reference, the ensemble of late-type galaxies (which invariably are Sérsic galaxies) follow M BH -M ,sph * and M BH -M ,gal * relations with slopes equal to 2.16±0.32 and 3.05±0.70, respectively. Finally, we provide some useful conversion coefficients, υ, accounting for the different stellar mass-to-light ratios used in the literature, and we report the discovery of a local, compact massive spheroid in NGC5252.

Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.

Using 145 early-and late-type galaxies (ETGs and LTGs) with directly-measured super-massive black hole masses, M BH , we build upon our previous discoveries that: (i) LTGs, most of which have been alleged to contain a pseudobulge, follow the relation M BH ∝ M 2.16±0.32 * ,sph ; and (ii) the ETG relation M BH ∝ M 1.27±0.07 * ,sph is an artifact of ETGs with/without disks following parallel M BH ∝ M 1.9±0.2 * ,sph relations which are offset by an order of magnitude in the M BH -direction. Here, we searched for substructure in the M BH -(central velocity dispersion, σ) diagram using our recently published, multicomponent, galaxy decompositions; investigating divisions based on the presence of a depleted stellar core (major dry-merger), a disk (minor wet/dry-merger, gas accretion), or a bar (evolved unstable disk). The Sérsic and core-Sérsic galaxies define two distinct relations: M BH ∝ σ 5.75±0.34 and M BH ∝ σ 8.64±1.10 , with ∆ rms|BH = 0.55 and 0.46 dex, respectively. We also report on the consistency with the slopes and bends in the galaxy luminosity (L)-σ relation due to Sérsic and core-Sérsic ETGs, and LTGs which all have Sérsic light-profiles. Two distinct relations (superficially) reappear in the M BHσ diagram upon separating galaxies with/without a disk (primarily for the ETG sample), while we find no significant offset between barred and non-barred galaxies, nor between galaxies with/without active galactic nuclei. We also address selection biases purported to affect the scaling relations for dynamically-measured M BH samples. Our new, (morphological type)-dependent, M BH -σ relations more precisely estimate M BH in other galaxies, and hold implications for galaxy/black hole co-evolution theories, simulations, feedback, the pursuit of a black hole fundamental plane, and calibration of virial f -factors for reverberation-mapping.