Response specificity of male moths to multicomponent pheromones

Research on numerous species of moths (Lepidoptera) has shown that the sex pheromones released by females for the purpose of attracting males to mate are multicomponent blends of chemicals. These pheromones serve as species-specific signals, and a major effort in pheromone research has been devoted to determining those factors that influence and control male response specificity. In this paper we review a series of studies conducted over the past 15 years designed to address the problems associated with measuring the sensitivity of males to blend composition and the influence of individual pheromone components on the active space of the pheromone. Emphasis is placed not only on what has been learned, but also on the changes in methodology that have occurred with advances in analytical procedures, and the importance of a close dialogue between those involved in chemical and behavioral studie

The polarized image of a synchrotron-emitting ring of gas orbiting a black hole

High Energy Astrophysic

Constraints on black-hole charges with the 2017 EHT observations of M87*

InstrumentationHigh Energy Astrophysic

The variability of the black hole image in M87 at the dynamical timescale

The black hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center of the M87 galaxy, this timescale (5–61 days) is comparable to the 6 day extent of the 2017 EHT observations. Closure phases along baseline triangles are robust interferometric observables that are sensitive to the expected structural changes of the images but are free of station-based atmospheric and instrumental errors. We explored the day-to-day variability in closure-phase measurements on all six linearly independent nontrivial baseline triangles that can be formed from the 2017 observations. We showed that three triangles exhibit very low day-to-day variability, with a dispersion of ∼3°–5°. The only triangles that exhibit substantially higher variability (∼90°–180°) are the ones with baselines that cross the visibility amplitude minima on the u–v plane, as expected from theoretical modeling. We used two sets of general relativistic magnetohydrodynamic simulations to explore the dependence of the predicted variability on various black hole and accretion-flow parameters. We found that changing the magnetic field configuration, electron temperature model, or black hole spin has a marginal effect on the model consistency with the observed level of variability. On the other hand, the most discriminating image characteristic of models is the fractional width of the bright ring of emission. Models that best reproduce the observed small level of variability are characterized by thin ring-like images with structures dominated by gravitational lensing effects and thus least affected by turbulence in the accreting plasmas.https://iopscience.iop.org/article/10.3847/1538-4357/ac332e/pdfPublished versio

Event Horizon Telescope observations of the jet launching and collimation in Centaurus A

InstrumentationLarge scale structure and cosmolog

A universal power-law prescription for variability from synthetic images of black hole accretion flows

Instrumentatio

First sagittarius A* Event Horizon Telescope results. VI. Testing the black hole metric

Galaxie

First M87 Event Horizon Telescope results. IX.: detection of near-horizon circular polarization

Galaxie