We present the final results from a high sampling rate, multi-month, spectrophotometric reverberation mapping campaign undertaken to obtain either new or improved Hβ reverberation lag measurements for several relatively low-luminosity active galactic nuclei (AGNs). We have reliably measured the time delay between variations in the continuum and Hβ emission line in six local Seyfert 1 galaxies. These measurements are used to calculate the mass of the supermassive black hole at the center of each of these AGNs. We place our results in context to the most current calibration of the broad-line region (BLR) R BLR -L relationship, where our results remove outliers and reduce the scatter at the low-luminosity end of this relationship. We also present velocity-resolved Hβ time-delay measurements for our complete sample, though the clearest velocity-resolved kinematic signatures have already been published.

Multiple planet systems provide an ideal laboratory for probing exoplanet composition, formation history and potential habitability. For the TRAPPIST-1 planets, the planetary radii are well established from transits [1,2], with reasonable mass estimates coming from transit timing variations [2, 3] and dynamical modeling [4]. The low bulk densities of the TRAPPIST-1 planets demand significant volatile content. Here we show using mass-radius-composition models, that TRAPPIST-1f and g likely contain substantial (≥ 50 wt%) water/ice, with b and c being significantly drier (≤ 15 wt%). We propose this gradient of water mass fractions implies planets f and g formed outside the primordial snow line whereas b and c formed inside. We find that compared to planets in our solar system that also formed within the snow line, TRAPPIST-1b and c contain hundreds more oceans worth of water. We demonstrate the extent and timescale of migration in the TRAPPIST-1 system depends on how rapidly the planets formed and the relative location of the primordial snow line. This work provides a framework for understanding the differences between the protoplanetary disks of our solar system versus M dwarfs. Our results provide key insights into the volatile budgets, timescales of planet formation, and migration history of likely the most common planetary host in the Galaxy.The derivation of a planetary composition from only its mass and radius is a notoriously difficult exercise because of the many degeneracies that exist. The geophysical and geochemical behavior of a planet is extremely sensitive to such factors as the size of the iron core, the mantle mineralogy, and the location of phase boundaries within any rock and ice layers [5,6]. For astrobiological applications it is crucial to constrain the exact amount of surficial water a planet contains. Yet current models assume only pure iron cores and an Earth-like composition for the mantles, and often assume either an iron core plus silicate mantle or a silicate planet plus ice mantle [7]. While useful for broadly constraining rocky versus volatile-rich composition, current mass-radius constraints often fail to meaningfully quantify the specific planetary composition [5,6]. For example, [4] constrained the masses of the TRAPPIST-1 planets using dynamical stability arguments, and found they were compatible with compositions between 0% and 100% water ice. The mass-radius fitting of [2] and [3] provided similar, but still uncertain, constraints. We argue that simultaneous mass-radiuscomposition fitting of all the TRAPPIST-1 planets, using the context from the planetary system as a whole, allows better quantification of the allowable structures and mineralogies given the mass-radius measurements and their uncertainties. We, therefore, analyzed the interior structures 1

A detailed analysis of the data from a high sampling rate, multi-month reverberation mapping campaign, undertaken primarily at MDM Observatory with supporting observations from telescopes around the world, reveals that the Hβ emission region within the broad line regions (BLRs) of several nearby AGNs exhibit a variety of kinematic behaviors. While the primary goal of this campaign was to obtain either new or improved Hβ reverberation lag measurements for several relatively low luminosity AGNs, we were also able to unambiguously reconstruct velocity-resolved reverberation signals from a subset of our targets. Through high cadence spectroscopic monitoring of the optical continuum and broad Hβ emission line variations observed in the nuclear regions of NGC 3227, NGC 3516, and NGC 5548, we clearly see evidence for outflowing, infalling, and virialized BLR gas motions, respectively.

An exoplanet's structure and composition are first-order controls of the planet's habitability. We explore which aspects of bulk terrestrial planet composition and interior structure affect the chief observables of an exoplanet: its mass and radius. We apply these perturbations to the Earth, the planet we know best. Using the mineral physics toolkit BurnMan to self-consistently calculate mass-radius models, we find that core radius, presence of light elements in the core and an upper-mantle consisting of low-pressure silicates have the largest effect on the final calculated mass at a given radius, none of which are included in current mass-radius models. We expand these results provide a self-consistent grid of compositionally as well as structurally constrained terrestrial mass-radius models for quantifying the likelihood of exoplanets being "Earth-like." We further apply this grid to Kepler-36b, finding that it is only ∼20% likely to be structurally similar to the Earth with Si/Fe = 0.9 compared to Earth's Si/Fe = 1 and Sun's Si/Fe = 1.19.

We present BurnMan, an open-source mineral physics toolbox to determine elastic properties for specified compositions in the lower mantle by solving an Equation of State (EoS). The toolbox, written in Python, can be used to evaluate seismic velocities of new mineral physics data or geodynamic models, and as the forward model in inversions for mantle composition. The user can define the composition from a list of minerals provided for the lower mantle or easily include their own. BurnMan provides choices in methodology, both for the EoS and for the multiphase averaging scheme. The results can be visually or quantitatively compared to observed seismic models. Example user scripts show how to go through these steps. This paper includes several examples realized with BurnMan: First, we benchmark the computations to check for correctness. Second, we exemplify two pitfalls in EoS modeling: using a different EoS than the one used to derive the mineral physical parameters or using an incorrect averaging scheme. Both pitfalls have led to incorrect conclusions on lower mantle composition and temperature in the literature. We further illustrate that fitting elastic velocities separately or jointly leads to different Mg/Si ratios for the lower mantle. However, we find that, within mineral physical uncertainties, a pyrolitic composition can match PREM very well. Finally, we find that uncertainties on specific input parameters result in a considerable amount of variation in both magnitude and gradient of the seismic velocities.

We analyze the absolute magnitude (M r ) and color (u − r) of low redshift (z < 0.06) galaxies in the Sloan Digital Sky Survey Data Release 6. Galaxies with nearly exponential profiles (Sloan parameter fracDeV < 0.1) all fall on the blue sequence of the color -magnitude diagram; if, in addition, these exponential galaxies have M r < −19, they show a dependence of u − r color on apparent axis ratio q expected for a dusty disk galaxy. By fitting luminosity functions for exponential galaxies with different values of q, we find that the dimming is well described by the relation ∆M r = 1.27(log q) 2 , rather than the ∆M ∝ log q law that is frequently assumed. When the absolute magnitudes of bright exponential galaxies are corrected to their "face-on" value, M f r = M r − ∆M r , the average u − r color is linearly dependent on M f r for a given value of q. Nearly face-on exponential galaxies (q > 0.9) have a shallow dependence of mean u − r color on M f r (0.096 magnitudes redder for every magnitude brighter); by comparison, nearly edge-on exponential galaxies (q < 0.3) are 0.265 magnitudes redder for every magnitude brighter. When the dimming law ∆M r ∝ (log q) 2 is used to create an inclination-corrected sample of bright exponential galaxies, their apparent shapes are confirmed to be consistent with a distribution of mildly non-circular disks, with median short-to-long axis ratio γ ≈ 0.22 and median disk ellipticity ǫ ≈ 0.08.

The interior composition of exoplanets is not observable, limiting our direct knowledge of their structure, composition, and dynamics. Recently described observational trends suggest that rocky exoplanets, that is, planets without significant volatile envelopes, are likely limited to <1.5 Earth radii. We show that given this likely upper limit in the radii of purely rocky super‐Earth exoplanets, the maximum expected core‐mantle boundary pressure and adiabatic temperature are relatively moderate, 630 GPa and 5000 K, while the maximum central core pressure varies between 1.5 and 2.5 TPa. We further find that for planets with radii less than 1.5 Earth radii, core‐mantle boundary pressure and adiabatic temperature are mostly a function of planet radius and insensitive to planet structure. The pressures and temperatures of rocky exoplanet interiors, then, are less than those explored in recent shock‐compression experiments, ab initio calculations, and planetary dynamical studies. We further show that the extrapolation of relevant equations of state does not introduce significant uncertainties in the structural models of these planets. Mass‐radius models are more sensitive to bulk composition than any uncertainty in the equation of state, even when extrapolated to terapascal pressures.

We present the first results from a high sampling rate, multi-month reverberation mapping campaign undertaken primarily at MDM Observatory with