NLTE 1.5D Modeling of Red Giant Stars

Spectra for 2D stars in the 1.5D approximation are created from synthetic spectra of 1D non-local thermodynamic equilibrium (NLTE) spherical model atmospheres produced by the PHOENIX code. The 1.5D stars have the spatially averaged Rayleigh-Jeans flux of a K3-4 III star, while varying the temperature difference between the two 1D component models ($\Delta T_{\mathrm{1.5D}}$), and the relative surface area covered. Synthetic observable quantities from the 1.5D stars are fitted with quantities from NLTE and local thermodynamic equilibrium (LTE) 1D models to assess the errors in inferred $T_{\mathrm{eff}}$ values from assuming horizontal homogeneity and LTE. Five different quantities are fit to determine the $T_{\mathrm{eff}}$ of the 1.5D stars: UBVRI photometric colors, absolute surface flux SEDs, relative SEDs, continuum normalized spectra, and TiO band profiles. In all cases except the TiO band profiles, the inferred $T_{\mathrm{eff}}$ value increases with increasing $\Delta T_{\mathrm{1.5D}}$. In all cases, the inferred $T_{\mathrm{eff}}$ value from fitting 1D LTE quantities is higher than from fitting 1D NLTE quantities and is approximately constant as a function of $\Delta T_{\mathrm{1.5D}}$ within each case. The difference between LTE and NLTE for the TiO bands is caused indirectly by the NLTE temperature structure of the upper atmosphere, as the bands are computed in LTE. We conclude that the difference between $T_{\mathrm{eff}}$ values derived from NLTE and LTE modelling is relatively insensitive to the degree of the horizontal inhomogeneity of the star being modeled, and largely depends on the observable quantity being fit.Comment: 46 pages, 14 figures, 7 tables, accepted for publication in ApJ on April 5, 201

NLTE and LTE Lick indices for red giants from [M/H] 0.0 to -6.0 at SDSS and IDS spectral resolution

We investigate the dependence of the complete system of 22 Lick indices on overall metallicity scaled from solar abundances, [M/H], from the solar value, 0.0, down to the extremely-metal-poor (XMP) value of -6.0, for late-type giant stars (MK luminosity class III, log(g)=2.0) of MK spectral class late-K to late-F (3750 < Teff < 6500 K) of the type that are detected as "fossils" of early galaxy formation in the Galactic halo and in extra-galactic structures. Our investigation is based on synthetic index values, I, derived from atmospheric models and synthetic spectra computed with PHOENIX in LTE and Non-LTE (NLTE), where the synthetic spectra have been convolved to the spectral resolution, R, of both IDS and SDSS (and LAMOST) spectroscopy. We identify nine indices, that we designate "Lick-XMP", that remain both detectable and significantly [M/H]-dependent down to [M/H] values of at least ~-5.0, and down to [M/H] ~ -6.0 in five cases, while also remaining well-behaved . For these nine, we study the dependence of I on NLTE effects, and on spectral resolution. For our LTE I values for spectra of SDSS resolution, we present the fitted polynomial coefficients, C_n, from multi-variate linear regression for I with terms up to third order in the independent variable pairs (Teff, [M/H]), and (V-K, [M/H]), and compare them to the fitted C_n values of Worthey et al. (1994) at IDS spectral resolution.Comment: Accepted for publication in the Astrophysical Journal. Tables 6 and 7 available electronically from the autho

Integrated light stellar population synthesis of globular clusters using non-local thermodynamic equilibrium modelling

xxix, 274 leaves : illustrations (chiefly colour) ; 29 cmIncludes abstract and appendices.Includes bibliographical references (leaves 158-165).We present an investigation of McWilliam & Bernstein's 2008 globular cluster (GC) stellar population synthesis method, focusing on the impact of non-local thermodynamic equilibrium (NLTE) modeling effects. For this purpose, we have generated comprehensive, fully NLTE libraries of individual stellar spectra and GC integrated light (IL) spectra. The stellar library spans large ranges in Teff, log g, and [M/H], reproduced for 0.5 and 1 M☉ and two degrees of &alpha;-enhancement. The IL library spans 9 to 15 Gyr in age, and -1.790 to -0.253 in [M/H]. The IL spectral library is used to investigate Johnson-Cousins-Bessel UBV IJK IL colours, sensitivity of IL spectral features to cluster age or metallicity, and deriving the ages and metallicities of 11 GCs for which IL spectra are acquired from Colucci, Bernstein &amp; McWilliam (2017). The IL colours confirm previously reported trends of GC reddening with increasing age or metallicity, and demonstrate that NLTE colours are bluer than LTE by up to a few tens of millimagnitudes, as are &alpha;-enhanced colours. We find a dependence of a few millimagnitudes on the discretization resolution of population CMDs when using the 25-30 boxes suggested in the literature. This dependence is minimized when the number of boxes increased to 40-50. We find 240 spectral features sensitive to either cluster age or metallicity, of which 209 are newly identified as potential GC diagnostic features. These features represent 19 different species, including Fe I, Fe II, Ca I, and Ti I. Chi-squared minimization is used to determine the best fit to the observed GC IL spectra, deriving ages for six of the 11 clusters, and metallicities for all of them. The uncertainties of both the ages and metallicities are reduced by a factor of two to three times when fit with NLTE IL spectra when compared with those from fitting LTE spectra

Non-Local Thermodynamic Equilibrium Transmission Spectrum Modelling of HD209458b

Context - Exoplanetary upper atmospheres are low density environments where radiative processes can compete with collisional ones and introduce non-local thermodynamic equilibrium (NLTE) effects into transmission spectra. Aims - We develop a NLTE radiative transfer framework capable of modelling exoplanetary transmission spectra over a wide range of planetary properties. Methods - We adapt the NLTE spectral synthesis code Cloudy to produce an atmospheric structure and atomic transmission spectrum in both NLTE and local thermodynamic equilibrium (LTE) for the hot Jupiter HD209458b, given a published T-P profile and assuming solar metallicity. Selected spectral features, including H$\alpha$, Na I D, He I $\lambda$10830, Fe I & II ultra-violet (UV) bands, and C, O and Si UV lines, are compared with literature observations and models where available. The strength of NLTE effects are measured for individual spectral lines to identify which features are most strongly affected. Results - The developed modelling framework computing NLTE synthetic spectra reproduces literature results for the He I $\lambda$10830 triplet, the Na I D lines, and the forest of Fe I lines in the optical. Individual spectral lines in the NLTE spectrum exhibit up to 40 % stronger absorption relative to the LTE spectrum.Comment: Accepted for publication in A&A, 15 pages, 13 figure

Thinking about feeling: using trait emotional intelligence in understanding the associations between early maladaptive schemas and coping styles

Objectives: Maladaptive interpersonal schemas can trigger distressing emotions and drive dysfunctional behaviour that leads to difficulties in interpersonal relationships and perpetuates the original maladaptive schemas. This study sought to identify patterns of association between trait emotional intelligence (TEI), early maladaptive schemas (EMS), and coping styles in a non‐clinical sample. Emotionality profiles were hypothesized to be associated with EMS severity and poorer coping, as early experiences can shape an individual's self‐perceptions through reinforcement by maladaptive responses. Design: Cross‐sectional study with 142 undergraduate students. Methods: We obtained self‐reports of TEI, coping styles, and EMS. Results: Disengagement coping was strongly correlated with EMS severity (r = .565, p < .01). TEI was negatively correlated with EMS (r = −.660, p < .01) and Disengagement (r = −.405, p < .01). Emotionality, Impaired Autonomy, and Overvigilance partially mediated the relationship between Disconnection and Emotion‐Focused Disengagement. Self‐Control fully mediated the relationship between Impaired Limits and Problem‐Focused Disengagement. Conclusions: The findings suggest that lower TEI is associated with the likelihood for maladaptive coping in response to EMS. The preference for certain coping styles associated with a particular domain of EMS may be explained by an individual's perceived metacognitive ability to regulate their stress and emotions. When individuals’ needs for love, safety, and acceptance from others are not met, there might be poorer perceived self‐efficacies in Emotionality and the tendency to cope through emotional avoidance. Individuals with difficulties establishing internal limits are more likely to respond with problem avoidance, possibly due to deficient distress tolerance. Longitudinal studies with a clinical population are warranted to replicate these findings

Hair of the Dog: Obtaining Samples From Coyotes and Wolves Noninvasively

Canids can be difficult to detect and their populations difficult to monitor. We tested whether hair samples could be collected from coyotes (Canis latrans) in Texas, USA and gray wolves (C. lupus) in Montana, USA using lure to elicit rubbing behavior at both man-made and natural collection devices. We usedmitochondrial and nuclearDNA to determine whether collected hair samples were from coyote, wolf, or nontarget species. Both coyotes and wolves rubbed on man-made barbed surfaces but coyotes in Texas seldom rubbed on hanging barbed surfaces. Wolves in Montana showed a tendency to rub at stations where natural material collection devices (sticks and debris) were present. Time to detection was relatively short (5 nights and 4 nights for coyotes and wolves, respectively) with nontarget and unknown species comprising approximately 26% of the detections in both locations. Eliciting rubbing behavior from coyotes and wolves using lures has advantages over opportunistic genetic sampling methods (e.g., scat transects) because it elicits a behavior that deposits a hair sample at a fixed sampling location, thereby increasing the efficiency of sampling for these canids. Hair samples from rub stations could be used to provide estimates of abundance, measures of genetic diversity and health, and detection–nondetection data useful for cost-effective population monitoring

Chandra ACIS-S Observations of Abell 4059: Signs of Dramatic Interaction Between a Radio Galaxy and a Galaxy Cluster

We present Chandra observations of the galaxy cluster A4059. We find strong evidence that the FR-I radio galaxy PKS 2354-35 at the center of A4059 is inflating cavities with radii ~20 kpc in the intracluster medium, similar to the situation seen in Perseus A and Hydra A. We also find evidence for interaction between the intracluster medium and PKS 2354-35 on small scales in the very center of the cluster. Arguments are presented suggesting that this radio galaxy has faded significantly in radio power (possibly from an FR-II state) over the past 10^8 yrs.Comment: Accepted for publication in ApJ Letters; figure 1a also included as high quality JPEG file for convenienc

Differential criterion of a bubble collapse in viscous liquids

The present work is devoted to a model of bubble collapse in a Newtonian viscous liquid caused by an initial bubble wall motion. The obtained bubble dynamics described by an analytic solution significantly depends on the liquid and bubble parameters. The theory gives two types of bubble behavior: collapse and viscous damping. This results in a general collapse condition proposed as the sufficient differential criterion. The suggested criterion is discussed and successfully applied to the analysis of the void and gas bubble collapses.Comment: 5 pages, 3 figure

Crystallization of a classical two-dimensional electron system: Positional and orientational orders

Crystallization of a classical two-dimensional one-component plasma (electrons interacting with the Coulomb repulsion in a uniform neutralizing positive background) is investigated with a molecular dynamics simulation. The positional and the orientational correlation functions are calculated for the first time. We have found an indication that the solid phase has a quasi-long-range (power-law) positional order along with a long-range orientational order. This indicates that, although the long-range Coulomb interaction is outside the scope of Mermin's theorem, the absence of ordinary crystalline order at finite temperatures applies to the electron system as well. The `hexatic' phase, which is predicted between the liquid and the solid phases by the Kosterlitz-Thouless-Halperin-Nelson-Young theory, is also discussed.Comment: 3 pages, 4 figures; Corrected typos; Double columne