Seventy new non-eclipsing BEER binaries discovered in CoRoT lightcurves and confirmed by RVs from AAOmega

We applied the BEER algorithm to the CoRoT lightcurves from the first five LRc fields and identified $481$ non-eclipsing BEER candidates with periodic lightcurve modulations and amplitudes of $0.5-87$ mmag. Medium-resolution spectra of $281$ candidates were obtained in a seven-night AAOmega radial-velocity (RV) campaign, with a precision of $\sim1$ km/s. The RVs confirmed the binarity of $70$ of the BEER candidates, with periods of $0.3-10$ days.Comment: 2 pages, 1 figure, to appear in the CoRoT Symposium 3, Kepler KASC-7 joint meeting, EPJ Web of Conference

BEER analysis of Kepler and CoRoT light curves. III. Spectroscopic confirmation of seventy new beaming binaries discovered in CoRoT light curves

(abridged for arXiv) The BEER algorithm searches stellar light curves for the BEaming, Ellipsoidal, and Reflection photometric modulations that are caused by a short-period companion. Applying the search to the first five long-run center CoRoT fields, we identified $481$ non-eclipsing candidates with periodic flux amplitudes of $0.5-87$ mmag. Optimizing the Anglo-Australian-Telescope pointing coordinates and the AAOmega fiber-allocations with dedicated softwares, we acquired six spectra for $231$ candidates and seven spectra for another $50$ candidates in a seven-night campaign. Analysis of the red-arm AAOmega spectra, which covered the range of $8342-8842\AA{}$, yielded a radial-velocity precision of $\sim1$ km/s. Spectra containing lines of more than one star were analyzed with the two-dimensional correlation algorithm TODCOR. The measured radial velocities confirmed the binarity of seventy of the BEER candidates$-45$ single-line binaries, $18$ double-line binaries, and $7$ diluted binaries. We show that red giants introduce a major source of false candidates and demonstrate a way to improve BEER's performance in extracting higher fidelity samples from future searches of CoRoT light curves. The periods of the confirmed binaries span a range of $0.3-10$ days and show a rise in the number of binaries per $\Delta$log$P$ toward longer periods. The estimated mass ratios of the double-line binaries and the mass ratios assigned to the single-line binaries, assuming an isotropic inclination distribution, span a range of $0.03-1$. On the low-mass end, we have detected two brown-dwarf candidates on a $\sim1$ day period orbit. This is the first time non-eclipsing beaming binaries are detected in CoRoT data, and we estimate that $\sim300$ such binaries can be detected in the CoRoT long-run light curves.Comment: 28 pages, 15 figures, and 11 tables. Accepted for publication in A&

Features of Gaia DR3 Spectroscopic Binaries I. Tidal circularization of Main-Sequence Stars

Previous studies pointed out that many observed samples of short-period binaries display a cutoff period, $P_{\rm cut}$, such that almost all binaries with periods shorter than $P_{\rm cut}$ have circular orbits. This feature is probably due to long-term circularization processes induced by tidal interaction between the two stars of each binary. It seemed as if coeval main-sequence (MS) samples of open clusters display $P_{\rm cut}$ that depends on the sample age. Using the unprecedentedly large sample of MS spectroscopic orbits recently released by $\textit{Gaia}$ we have found that the $P_{\rm cut}$ does not depend on the stellar age but, instead, varies with stellar temperature, decreasing linearly from $6.5$ day at $T_{\rm eff}\sim 5700$ K to $\sim 2.5$ day at $6800$ K. $P_{\rm cut}$ was derived by a new algorithm that relied on clear upper envelopes displayed in the period-eccentricity diagrams. Our $P_{\rm cut}$ determines both the border between the circular and eccentric binaries and the location of the upper envelope. The results are inconsistent with the theory which assumes circularization occurs during the stellar MS phase, a theory that was adopted by many studies. The circularization has probably taken place at the pre-main-sequence phase, as suggested already in 1989 by Zahn and Bouchet, and later by Khaluillin and Khaluillina in 2011. Our results suggest that the weak dependence of $P_{\rm cut}$ on the cluster age is not significant, and/or might be due to the different temperatures of the samples. If indeed true, this has far-reaching implications for the theory of binary and exoplanet circularization, synchronization, and alignment.Comment: 13 pages, 12 figures, 2 tables. Accepted for publication in MNRA

An Experimental Investigation of Epistemic Modal Adverbs and Adjectives

This paper analyses epistemic modal adverbs and adjectives, both theoretically and experimentally, while addressing the prevalent conceptions of modality and context update. While modality is standardly viewed and represented uniformly, we show that epistemic modal adverbs and adjectives differ in various linguistic environments, and present experimental evidence that supports the claim that epistemic modal adverbs and adjectives differ in terms of cognitive processing. While context update is standardly viewed as a two-stage process composed of assertion and acceptance/rejection, we present experimental evidence that supports the claim that there is also a stage of evaluation, in which the hearer considers the content of the assertion and the implications of adding this content to the common ground

Troll and Divide: The Language of Online Polarization

The affective animosity between the political left and right has grown steadily in many countries over the past few years, posing a threat to democratic practices and public health. There is a rising concern over the role that ‘bad actors’ or trolls may play in the polarization of online networks. In this research, we examined the processes by which trolls may sow intergroup conflict through polarized rhetoric. We developed a dictionary to assess online polarization by measuring language associated with communications that display partisan bias in their diffusion. We validated the polarized language dictionary in four different contexts and across multiple time periods. The polarization dictionary made out-of-set predictions, generalized to both new political contexts (#BlackLivesMatter) and a different social media platform (Reddit), and predicted partisan differences in public opinion polls about COVID-19. Then we analyzed tweets from a known Russian troll source (N = 383,510) and found that their use of polarized language has increased over time. We also compared troll tweets from three countries (N = 798,33) and found that they all utilize more polarized language than regular Americans (N = 1,507,300) and trolls have increased their use of polarized rhetoric over time. We also find that polarized language is associated with greater engagement, but this association only holds for politically engaged users (both trolls and regular users). This research clarifies how trolls leverage polarized language and provides an open-source, simple tool for exploration of polarized communications on social media