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We present ionized gas kinematics for 681 galaxies at z &tild; 1.4-3.8 from the MOSFIRE Deep Evolution Field survey, measured using models that account for random galaxy-slit misalignments together with structural parameters derived from CANDELS Hubble Space Telescope (HST) imaging. Kinematics and sizes are used to derive dynamical masses. Baryonic masses are estimated from stellar masses and inferred gas masses from dust-corrected star formation rates (SFRs) and the Kennicutt-Schmidt relation. We measure resolved rotation for 105 galaxies. For the remaining 576 galaxies we use models based on HST imaging structural parameters together with integrated velocity dispersions and baryonic masses to statistically constrain the median ratio of intrinsic ordered to disordered motion,. We find that increases with increasing stellar mass and decreasing specific SFR (sSFR). These trends may reflect marginal disk stability, where systems with higher gas fractions have thicker disks. For galaxies with detected rotation we assess trends between their kinematics and mass, sSFR, and baryon surface density (Σbar,e). Intrinsic dispersion correlates most with Σbar,e, and velocity correlates most with mass. By comparing dynamical and baryonic masses, we find that galaxies at z &tild; 1.4-3.8 are baryon dominated within their effective radii (RE), with Mdyn/Mbaryon increasing over time. The inferred baryon fractions within RE, fbar, decrease over time, even at fixed mass, size, or surface density. At fixed redshift, fbar does not appear to vary with stellar mass but increases with decreasing RE and increasing Σbar,e. For galaxies at z ≥ 2, the median inferred baryon fractions generally exceed 100%. We discuss possible explanations and future avenues to resolve this tension.

We present Karl Jansky Very Large Array observations of the CO J = 1 - 0 transition in a sample of four z ∼ 2 main-sequence galaxies. These galaxies are in the blue sequence of star-forming galaxies at their redshift, and are part of the IRAM Plateau de Bure HIgh-z Blue Sequence Survey which imaged them in CO J = 3 - 2. Two galaxies are imaged here at high signal-to-noise, allowing determinations of their disk sizes, line profiles, molecular surface densities, and excitation. Using these and published measurements, we show that the CO and optical disks have similar sizes in main-sequence galaxies, and in the galaxy where we can compare CO J = 1 - 0 and J = 3 - 2 sizes we find these are also very similar. Assuming a Galactic CO-to-H2 conversion, we measure surface densities of Smol ∼ 1200 M⊙ pc-2 in projection and estimate ∑mol ∼ 500-900 M⊙ pc-2 deprojected. Finally, our data yields velocity-integrated Rayleigh-Jeans brightness temperature line ratios r31 that are approximately at unity. In addition to the similar disk sizes, the very similar line profiles in J = 1 - 0 and J = 3 - 2 indicate that both transitions sample the same kinematics, implying that their emission is coextensive. We conclude that in these two main-sequence galaxies there is no evidence for significant excitation gradients or a large molecular reservoir that is diffuse or cold and not involved in active star formation. We suggest that r31 in very actively star-forming galaxies is likely an indicator of how well-mixed the star formation activity and the molecular reservoir are.

We combine molecular gas masses inferred from CO emission in 500 star-forming galaxies (SFGs) between z = 0 and 3, from the IRAM-COLDGASS, PHIBSS1/2, and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas depletion timescale (tdepl) and gas to stellar mass ratio (Mmol gas/M∗) of SFGs near the star formation "main-sequence" with redshift, specific star-formation rate (sSFR), and stellar mass (M∗). The CO- and dust-based scaling relations agree remarkably well. This suggests that the CO → H2 mass conversion factor varies little within ±0.6 dex of the main sequence (sSFR(ms, z, M∗)), and less than 0.3 dex throughout this redshift range. This study builds on and strengthens the results of earlier work. We find that tdepl scales as (1 + z)-0.3 × (sSFR/sSFR(ms, z, M∗))-0.5, with little dependence on M∗. The resulting steep redshift dependence of Mmol gas/M∗≈ (1 + z)3 mirrors that of the sSFR and probably reflects the gas supply rate. The decreasing gas fractions at high M∗are driven by the flattening of the SFR-M∗relation. Throughout the probed redshift range a combination of an increasing gas fraction and a decreasing depletion timescale causes a larger sSFR at constant M∗. As a result, galaxy integrated samples of the Mmol gas-SFR rate relation exhibit a super-linear slope, which increases with the range of sSFR. With these new relations it is now possible to determine Mmol gas with an accuracy of ±0.1 dex in relative terms, and ±0.2 dex including systematic uncertainties.

We report matched resolution imaging spectroscopy of the CO 3-2 e (with the IRAM Plateau de Bure millimeter interferometer) and of the Hα e (with LUCI at the Large Binocular Telescope) in the massive z = 1.53 main-sequence galaxy EGS 13011166, as part of the "Plateau de Bure high-z, blue-sequence survey" (PHIBSS: Tacconi et al.). We combine these data with Hubble Space Telescope V-I-J-H-band maps to derive spatially resolved distributions of stellar surface density, star formation rate, molecular gas surface density, optical extinction, and gas kinematics. The spatial distribution and kinematics of the ionized and molecular gas are remarkably similar and are well modeled by a turbulent, globally Toomre unstable, rotating disk. The stellar surface density distribution is smoother than the clumpy rest-frame UV/optical light distribution and peaks in an obscured, star-forming massive bulge near the dynamical center. The molecular gas surface density and the effective optical screen extinction track each other and are well modeled by a "mixed" extinction model. The inferred slope of the spatially resolved molecular gas to star formation rate relation, N = dlogΣstar form/dlogΣmol gas, depends strongly on the adopted extinction model, and can vary from 0.8 to 1.7. For the preferred mixed dust-gas model, we find N = 1.14 ± 0.1. © 2013. The American Astronomical Society. All rights reserved.

Owing to their similarities with giant exoplanets, brown dwarf companions of stars provide insights into the fundamental processes of planet formation and evolution. From their orbits, several brown dwarf companions are found to be more massive than theoretical predictions given their luminosities and the ages of their host stars 1-3 . Either the theory is incomplete or these objects are not single entities. For example, they could be two brown dwarfs each with a lower mass and intrinsic luminosity 1,4 . The most problematic example is Gliese 229 B (refs.  5,6 ), which is at least 2-6 times less luminous than model predictions given its dynamical mass of 71.4 ± 0.6 Jupiter masses (M Jup ) (ref.  1 ). We observed Gliese 229 B with the GRAVITY interferometer and, separately, the CRIRES+ spectrograph at the Very Large Telescope. Both sets of observations independently resolve Gliese 229 B into two components, Gliese 229 Ba and Bb, settling the conflict between theory and observations. The two objects have a flux ratio of 0.47 ± 0.03 at a wavelength of 2 μm and masses of 38.1 ± 1.0 and 34.4 ± 1.5 M Jup , respectively. They orbit each other every 12.1 days with a semimajor axis of 0.042 astronomical units (AU). The discovery of Gliese 229 BaBb, each only a few times more massive than the most massive planets, and separated by 16 times the Earth-moon distance, raises new questions about the formation and prevalence of tight binary brown dwarfs around stars., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Tight relationships exist in the local Universe between the central stellar properties of galaxies and the mass of their supermassive black hole (SMBH) 1-3 . These suggest that galaxies and black holes co-evolve, with the main regulation mechanism being energetic feedback from accretion onto the black hole during its quasar phase 4-6 . A crucial question is how the relationship between black holes and galaxies evolves with time; a key epoch to examine this relationship is at the peaks of star formation and black hole growth 8-12 billion years ago (redshifts 1-3) 7 . Here we report a dynamical measurement of the mass of the black hole in a luminous quasar at a redshift of 2, with a look back in time of 11 billion years, by spatially resolving the broad-line region (BLR). We detect a 40-μas (0.31-pc) spatial offset between the red and blue photocentres of the Hα line that traces the velocity gradient of a rotating BLR. The flux and differential phase spectra are well reproduced by a thick, moderately inclined disk of gas clouds within the sphere of influence of a central black hole with a mass of 3.2 × 10 8  solar masses. Molecular gas data reveal a dynamical mass for the host galaxy of 6 × 10 11  solar masses, which indicates an undermassive black hole accreting at a super-Eddington rate. This suggests a host galaxy that grew faster than the SMBH, indicating a delay between galaxy and black hole formation for some systems., (© 2024. The Author(s).)

During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potential to test one part of the Einstein equivalence principle: the local position invariance (LPI). We study the dependency of different atomic transitions on the gravitational potential to give an upper limit on violations of the LPI. This is done by separately measuring the redshift from hydrogen and helium absorption lines in the stellar spectrum during its closest approach to the black hole. For this measurement we use radial velocity data from 2015 to 2018 and combine it with the gravitational potential at the position of S2, which is calculated from the precisely known orbit of S2 around the black hole. This results in a limit on a violation of the LPI of |β_{He}-β_{H}|=(2.4±5.1)×10^{-2}. The variation in potential that we probe with this measurement is six magnitudes larger than possible for measurements on Earth, and a factor of 10 larger than in experiments using white dwarfs. We are therefore testing the LPI in a regime where it has not been tested before.

In the cold dark matter cosmology, the baryonic components of galaxies-stars and gas-are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius-a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

Most present-day galaxies with stellar masses ≥10(11) solar masses show no ongoing star formation and are dense spheroids. Ten billion years ago, similarly massive galaxies were typically forming stars at rates of hundreds solar masses per year. It is debated how star formation ceased, on which time scales, and how this "quenching" relates to the emergence of dense spheroids. We measured stellar mass and star-formation rate surface density distributions in star-forming galaxies at redshift 2.2 with ~1-kiloparsec resolution. We find that, in the most massive galaxies, star formation is quenched from the inside out, on time scales less than 1 billion years in the inner regions, up to a few billion years in the outer disks. These galaxies sustain high star-formation activity at large radii, while hosting fully grown and already quenched bulges in their cores., (Copyright © 2015, American Association for the Advancement of Science.)

Stars form from cold molecular interstellar gas. As this is relatively rare in the local Universe, galaxies like the Milky Way form only a few new stars per year. Typical massive galaxies in the distant Universe formed stars an order of magnitude more rapidly. Unless star formation was significantly more efficient, this difference suggests that young galaxies were much more molecular-gas rich. Molecular gas observations in the distant Universe have so far largely been restricted to very luminous, rare objects, including mergers and quasars, and accordingly we do not yet have a clear idea about the gas content of more normal (albeit massive) galaxies. Here we report the results of a survey of molecular gas in samples of typical massive-star-forming galaxies at mean redshifts of about 1.2 and 2.3, when the Universe was respectively 40% and 24% of its current age. Our measurements reveal that distant star forming galaxies were indeed gas rich, and that the star formation efficiency is not strongly dependent on cosmic epoch. The average fraction of cold gas relative to total galaxy baryonic mass at z = 2.3 and z = 1.2 is respectively about 44% and 34%, three to ten times higher than in today's massive spiral galaxies. The slow decrease between z approximately 2 and z approximately 1 probably requires a mechanism of semi-continuous replenishment of fresh gas to the young galaxies.

Objective: This study evaluates an educational intervention focusing on the ethical reasoning and communication skills necessary in counseling patients about morally objectionable medical interventions., Study Design: All students on the core clerkship in obstetrics and gynecology at the University of Miami Miller School of Medicine participated in a structured workshop. Students completed anonymous surveys before and after the workshop. Associations between the participants' change in comfort level in providing nondirective counseling and measured demographic variables were analyzed., Results: Of 140 students, 37% (n = 52) positively changed their comfort level with nondirective options counseling; 10% (n = 14) negatively changed. Change in understanding of the physician's role was reported by 60% (n = 84). The exercise was rated as educationally valuable by 95% (n = 128), with 84% (n = 115) attesting that the workshop would help them "approach things differently.", Conclusion: Evaluation of multiple parameters demonstrated that this workshop heightened student awareness of the ethical and communications skills challenges posed by this clinical situation.

Observations and theoretical simulations have established a framework for galaxy formation and evolution in the young Universe. Galaxies formed as baryonic gas cooled at the centres of collapsing dark-matter haloes; mergers of haloes and galaxies then led to the hierarchical build-up of galaxy mass. It remains unclear, however, over what timescales galaxies were assembled and when and how bulges and disks--the primary components of present-day galaxies--were formed. It is also puzzling that the most massive galaxies were more abundant and were forming stars more rapidly at early epochs than expected from models. Here we report high-angular-resolution observations of a representative luminous star-forming galaxy when the Universe was only 20% of its current age. A large and massive rotating protodisk is channelling gas towards a growing central stellar bulge hosting an accreting massive black hole. The high surface densities of gas, the high rate of star formation and the moderately young stellar ages suggest rapid assembly, fragmentation and conversion to stars of an initially very gas-rich protodisk, with no obvious evidence for a major merger.