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\"For the Crunk Feminist Collective, their academic day jobs were lacking in conversations they actually wanted-relevant, real conversations about how race and gender politics intersect with pop culture and current events. To address this void, they started a blog. Now with an annual readership of nearly one million, their posts foster dialogue about activist methods, intersectionality, and sisterhood. And the writers' personal identities-as black women; as sisters, daughters, and lovers; and as television watchers, sports fans, and music lovers-are never far from the discussion at hand. These essays explore \"Sex and Power in the Black Church,\" discuss how \"Clair Huxtable is Dead,\" list \"Five Ways Talib Kweli Can Become a Better Ally to Women in Hip Hop,\" and dwell on \"Dating with a Doctorate (She Got a Big Ego?).\" Self-described as \"critical homegirls,\" the authors tackle life stuck between loving hip hop and ratchet culture while hating patriarchy, misogyny, and sexism. Brittney Cooper is an assistant professor at Rutgers University. In addition to a weekly column in Salon.com, her words have appeared in the New York Times, the Washington Post, Cosmo.com, and many others. In 2013 and 2014, she was named to the Root.com's Root 100, an annual list of Top Black Influencers. Susana M. Morris received her Ph.D. from Emory University and is currently an associate professor of English at Auburn University. Robin M. Boylorn is assistant professor at the University of Alabama. She is the author of the award-winning monograph Sweetwater: Black Women and Narratives of Resilience (Peter Lang, 2013)\"-- Provided by publisher.

Earth’s deep mantle hosts enigmatic structures known as Large Low Velocity Provinces (LLVPs), which sit atop the core–mantle boundary and influence mantle dynamics and plume generation. Understanding their origin is central to reconstructing Earth’s early thermal and compositional evolution. Several hypotheses suggest that present-day LLVPs are the disrupted remnants of a globally continuous dense layer that formed early in Earth’s history. In this study, we show that a laterally continuous, non-convecting proto-LLVP layer would have severely inhibited strong plume formation and suppressed upper mantle melting throughout the Archean contradicting extensive geological evidence for widespread volcanism and early crust formation. By incorporating melting in global mantle convection models, we find that even high mantle potential temperatures, increased radiogenic heating in the basal layer, and elevated core-mantle boundary temperatures cannot overcome the thermal and physical barrier imposed by a continuous non-convecting basal layer. These findings rule out the scenario of a globally continuous basal layer in early Earth, prior to modern-style plate tectonics, and instead support hypotheses of LLVP formation as spatially separate or later-evolving structures. By reconciling mantle dynamics with observed Archean melting signatures, this study places strong constraints on the timing and geometry of LLVP formation, advancing our understanding of Earth’s early thermal evolution and the origin of deep mantle anomalies.

Gas supply to the stars Star formation requires the presence of cold molecular gas, which makes up only a small fraction of the total mass of the Milky Way and nearby galaxies where only a few new stars are formed per year. To establish whether the rapid star formation occurring in distant massive galaxies reflects a greater supply of cold gas or a more efficient process of star formation, gas content was surveyed in massive-star-forming galaxies at two cosmic epochs — at redshifts of approximately 1.2 and 2.3, when the Universe was 40% and 24% of its current age. The results 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 mass is three to ten times higher in distant galaxies than in today's massive spiral galaxies. Stars form from cold molecular interstellar gas, which is relatively rare in the local Universe, such that galaxies like the Milky Way form only a few new stars per year. However, typical massive galaxies in the distant Universe formed stars much more rapidly, suggesting that young galaxies were more rich in molecular gas. The results of a survey of molecular gas in samples of typical massive star-forming galaxies when the Universe was 40% and 24% of its current age now reveal that distant star-forming galaxies were indeed gas rich. 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 1 , 2 . 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 3 , 4 , 5 , 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 < z > 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 6 . The slow decrease between z  ≈ 2 and z  ≈ 1 probably requires a mechanism of semi-continuous replenishment of fresh gas to the young galaxies.

Many quiescent galaxies discovered in the early Universe by JWST raise fundamental questions on when and how these galaxies became and stayed quenched. Making use of the latest version of the semianalytic model GAEA that provides good agreement with the observed quenched fractions up to z ∼ 3, we make predictions for the expected fractions of quiescent galaxies up to z ∼ 7 and analyze the main quenching mechanism. We find that in a simulated box of 685 Mpc on a side, the first quenched massive (M ⋆ ∼ 1011 M ⊙), Milky Way–mass, and low-mass (M ⋆ ∼ 109.5 M ⊙) galaxies appear at z ∼ 4.5, z ∼ 6.2, and before z = 7, respectively. Most quenched galaxies identified at early redshifts remain quenched for more than 1 Gyr. Independently of galaxy stellar mass, the dominant quenching mechanism at high redshift is accretion disk feedback (quasar winds) from a central massive black hole, which is triggered by mergers in massive and Milky Way–mass galaxies and by disk instabilities in low-mass galaxies. Environmental stripping becomes increasingly more important at lower redshift.

We present the analysis of an ancient galaxy at z = 2.675, which we dub “Eridu.” Simultaneously modeling the JWST/NIRSpec G140M and G235M spectra from the SMILES program and 0.4–25 μm Hubble Space Telescope, JWST/NIRCam, and JWST/MIRI photometry from the JADES+SMILES photometric catalogs shows that Eridu is massive and quiescent, with stellar mass log(M*/M⊙)=10.96−0.01+0.01 and average star formation rate <1M⊙ yr−1 over the last 100 Myr. Star formation histories (SFHs) inferred from various models produce disconcertingly early and fast formation within ∼300 Myr of the Big Bang and quenching 2 Gyr prior to observation (z ∼ 10). This stellar mass assembly implies a M* ≈ 1011M⊙ progenitor at z > 10, nearly 2 orders of magnitude more than the most massive current high-redshift observations. From Eridu’s spectrum, we infer [Mg/Fe]=+0.65−0.19+0.20 , indicating its stellar population is extremely α-enhanced, consistent with the rapid formation timescale inferred from its SFH. We show that the inferred metallicity varies ∼0.4 dex between solar-scaled and α-enhanced models. As α-enhancement is expected in high-z quiescent galaxies, we speculate the common practice of spectral energy distribution modeling with solar-scaled abundance patterns could systematically affect the inferred ages of these objects. Eridu inhabits a massive protostructure that offers additional explanations for rapid mass assembly and quenching via environmental mechanisms, e.g., major mergers. Although its inferred formation is at odds with observations of the brightest z > 10 galaxies, future high-redshift galaxy formation studies and updated α-enhanced stellar models will unearth how Eridu and the first quiescent galaxies formed in the extremely early Universe.

Deep and wide-field near-infrared (NIR) surveys have recently discovered and confirmed ultramassive galaxies (UMGs; log(M⋆/M⊙) > 11) spectroscopically at z ≳ 3. However, most are characterized using only ultraviolet (UV)-to-NIR photometry, offering limited insight into obscured star formation and active galactic nucleus (AGN) activity. In this work, we add 10 far-infrared (FIR)-to-radio passbands to the existing UV-to-NIR catalogs for two spectroscopically confirmed UMGs from the MAGAZ3NE survey, COS-DR3-195616 (zspec = 3.255) and COS-DR1-209435 (zspec = 2.481). Utilizing the full UV-to-radio photometry, we revise our earlier UV-NIR-based interpretation of the nature of these galaxies. While both were previously identified as quiescent, our analysis reveals that 195616 is an unobscured galaxy undergoing quenching, and 209435 is a heavily obscured, actively star-forming UMG. We find that 195616 has already depleted most of its molecular gas and is expected to experience minimal future stellar mass growth. In contrast, 209435 contains a substantial molecular gas reservoir and has a prolonged depletion timescale. It is anticipated to increase 0.34 dex in stellar mass, reaching a stellar mass of log(M⋆/M⊙) = 11.72 over the next 0.72 Gyr. We present multipronged evidence for AGN activity in both UMGs. Our findings suggest a scenario where AGN feedback in 195616 may have contributed to gas depletion during quenching, while 209435 remains actively star-forming despite hosting an obscured AGN. Our work shows the importance of FIR-to-radio observations for accurately inferring the nature and properties of galaxies at z ≳ 3.

The changes in colors across a galaxy are intimately connected to the galaxy’s formation, growth, quenching history, and dust content. A particularly important epoch in the growth of galaxies is near z ∼ 2, often referred to as “cosmic noon,” where galaxies on average reach the peak of their star formation. We study a population of 125 cluster galaxies at z ∼ 1.6 in three Hubble Space Telescope filters, F475W, F625W, and F160W, roughly corresponding to the rest-frame far-ultraviolet, near-ultraviolet, and r band, respectively. By comparing to a control sample of 200 field galaxies at similar redshift, we reveal clear, statistically significant differences in the overall spatially resolved colors and color gradients in galaxies across these two different environments. On average, cluster galaxies have redder ultraviolet colors in both the inner and outer regions bounded by r 50, as well as an overall wider dispersion of outside-in color gradients. The presence of these observed differences, along with evidence from ancillary data from previous studies, strongly suggests that the environment drives these population-level color differences, by affecting the stellar populations and/or dust content.

We investigate the resolved kinematics of the molecular gas, as traced by the Atacama Large Millimeter/submillimeter Array in CO (2−1), of 25 cluster member galaxies across three different clusters at a redshift of z ∼ 1.6. This is the first large-scale analysis of the molecular gas kinematics of cluster galaxies at this redshift. By separately estimating the rotation curve of the approaching and receding sides of each galaxy via kinematic modeling, we quantify the difference in total circular velocity to characterize the overall kinematic asymmetry of each galaxy. 3/14 of the galaxies in our sample that we are able to model have similar degrees of asymmetry as that observed in galaxies in the field at similar redshift based on observations of mainly ionized gas. However, this leaves 11/14 galaxies in our sample with significantly higher asymmetry, and some of these galaxies have degrees of asymmetry of up to ∼50 times higher than field galaxies observed at similar redshift. Some of these extreme cases also have one-sided tail-like morphology seen in the molecular gas, supporting a scenario of tidal and/or ram pressure interaction. Such stark differences in the kinematic asymmetry in clusters versus the field suggest the evolutionary influence of dense environments, established as being a major driver of galaxy evolution at low redshift, is also active in the high-redshift universe.

We present the Local Volume Complete Cluster Survey (LoVoCCS; we pronounce it as “low-vox” or “law-vox,” with stress on the second syllable), an NSF’s National Optical-Infrared Astronomy Research Laboratory survey program that uses the Dark Energy Camera to map the dark matter distribution and galaxy population in 107 nearby (0.03 < z < 0.12) X-ray luminous ([0.1–2.4 keV] L X500 > 1044 erg s−1) galaxy clusters that are not obscured by the Milky Way. The survey will reach Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) Year 1–2 depth (for galaxies r = 24.5, i = 24.0, signal-to-noise ratio (S/N) > 20; u = 24.7, g = 25.3, z = 23.8, S/N > 10) and conclude in ∼2023 (coincident with the beginning of LSST science operations), and will serve as a zeroth-year template for LSST transient studies. We process the data using the LSST Science Pipelines that include state-of-the-art algorithms and analyze the results using our own pipelines, and therefore the catalogs and analysis tools will be compatible with the LSST. We demonstrate the use and performance of our pipeline using three X-ray luminous and observation-time complete LoVoCCS clusters: A3911, A3921, and A85. A3911 and A3921 have not been well studied previously by weak lensing, and we obtain similar lensing analysis results for A85 to previous studies. (We mainly use A3911 to show our pipeline and give more examples in the Appendix.)

The Europan ice shell is thought to be simultaneously a key contributor and a barrier to the underlying ocean’s habitability. Life-supporting oxidants formed by surface radiolysis have the potential to be a significant component toward the long-term sustenance of a Europan biosphere. However, these oxidants must first be transported through the ice shell to its base in order to be accessible by Europa’s ocean. We propose that a viscous lithospheric foundering process (“dripping”) driven by densification and weakening in salt-rich surface ice may provide a pathway for these surface oxidants to reach the ocean. We find that a viscous dripping process is capable of cycling surface ice to the base of the shell, transporting it in 3 Myr or less, depending on the level of salt-driven lithospheric weakening. Lithospheric drips can accommodate tens of kilometers of surface convergence within the salt-enriched region of the shell. We discover that the surrounding salt-poor ice locks the boundaries of the dripping region in place, encouraging lithospheric thinning and extension. We conclude that this dripping process is a viable avenue toward providing the mechanism for surface ice transport that could support Europan ocean habitability, but more work is needed to fully understand how the presence of saline ice affects ice shell deformation and dynamic behavior.