The high electron temperature in galaxy clusters (> 1 keV or > 10(7) K) leads to corrections at the level of a few percent in their thermal Sunyaev-Zeldovich effect signatures. Both the size and frequency dependence of these corrections, which are known as relativistic temperature corrections, depend upon the temperature of the objects. In this work we exploit this effect to measure the average temperature of a stack of Compton-y selected clusters. Specifically, we apply the "spectroscopic method" and search for the temperature that best fits the clusters' signal measured at frequencies from 30 to 545 GHz by the Atacama Cosmology Telescope and Planck satellite. We measure the average temperature of clusters detected in the Atacama Cosmology Telescope maps to be 8.5 + 2.4 keV, with an additional systematic error of comparable amplitude dominated by passband uncertainty. Upcoming surveys, such as the Simons Observatory and CMB-S4, have the potential to dramatically improve upon these measurements and thereby enable precision studies of cluster temperatures with millimeter observations. The key challenge for future observations will be mitigating instrumental systematic effects, which already limit this analysis.
We use a series of online surveys to study how US consumers' house price expectations respond to interest rate expectations. Communication about interest rates has little effect on average house price expectations, since households have heterogeneous beliefs about the relationship between interest rates and house prices. When coupled with an explanation of the mortgage rate channel, communication about interest rates has much larger effects on house price expectations. We also show that audio and visual communication have additional effects on expectations beyond the effects of text-based communications. Consumers' personal experiences appear to shape their mental models of the housing market and the responsiveness of their house price expectations to interest rate expectations.
Social factors such as demographic traits and institutional prestige structure the creation and dissemination of ideas in academic publishing. One place these effects can be observed is in how central or peripheral a researcher is in the coauthorship network. Here we investigate inequities in network centrality in a hand-collected data set of 5,670 U.S.-based faculty employed in Ph.D.-granting Computer Science departments and their DBLP coauthorship connections. We introduce algorithms for combining name- and perception-based demographic labels by maximizing alignment with self-reported demographics from a survey of faculty from our census. We find that women and individuals with minoritized race identities are less central in the computer science coauthorship network, implying worse access to and ability to spread information. Centrality is also highly correlated with prestige, such that faculty in top-ranked departments are at the core and those in low-ranked departments are in the peripheries of the computer science coauthorship network. We show that these disparities can be mitigated using simulated edge interventions, interpreted as facilitated collaborations. Our intervention increases the centrality of target individuals, chosen independently of the network structure, by linking them with researchers from highly ranked institutions. When applied to scholars during their Ph.D., the intervention also improves the predicted rank of their placement institution in the academic job market. This work was guided by an ameliorative approach: uncovering social inequities in order to address them. By targeting scholars for intervention based on institutional prestige, we are able to improve their centrality in the coauthorship network that plays a key role in job placement and longer-term academic success.
The mean pairwise velocity of massive halos reflects the gravitational force law on cosmic scales. We combine cosmic microwave background intensity maps from the Atacama Cosmology Telescope and a galaxy catalog from the Sloan Digital Sky Survey to estimate the mean pairwise velocity using the kinematic Sunyaev-Zeldovich (kSZ) effect. On scales from 30 to 230 megaparsecs, we constrain the gravitational acceleration between pairs of halos at separation r to be g∝1/r^{n} with n=2.1±0.3, which is consistent with Newtonian gravity in an expanding spacetime (i.e., the standard ΛCDM model). This constraint shows agreement with an inverse quadratic radial dependence over the large distances separating galaxy halos, as expected in standard cosmology. Upcoming surveys have the potential to rule out n=1 at 10σ significance. Our results establish the kSZ effect as a powerful tool for testing gravity on cosmological scales.
The distance to the Vela Junior supernova remnant (RX J0852.0–4622 or G266.2–1.2) has long remained uncertain, limiting our understanding of its physical properties. Using Very Large Telescope/Multi Unit Spectroscopic Explorer integral field spectroscopy, we uncover chemical and kinematic connections between the nebula surrounding its central compact object (CXOU J085201.4–461753) and the nearby Herbig–Haro outflow of Ve 7–27 (Wray 16–30), indicating a shared nitrogen-rich, Fe-peak-enhanced environment. This link ties stellar birth and death, with the young star Ve 7–27 embedded in material expelled by Vela Junior’s massive progenitor, and the remnant’s blast wave is expanding through the same medium. Adopting the Gaia-based distance to Ve 7–27, we revise Vela Junior’s distance to 1.41 ± 0.14 kpc. At this distance, the remnant’s physical radius is 23.3 ± 2.3 pc, and X-ray proper motions of the northwestern rim correspond to shock speeds of (2.8 ± 0.7) × 10 ^3 to (5.6 ± 1.5) × 10 ^3 km s ^−1 . These imply an age of ∼1.6–3.3 kyr and a very low ambient density, indicating that Vela Junior is expanding within a highly rarefied wind-blown cavity carved by a massive progenitor—consistent with the nondetection of strong thermal X-ray emission. This distance update also resolves long-standing inconsistencies, with major implications for its energy budget, particle acceleration efficiency, and compact object evolution.
