•Grammatical and stereotypical gender mismatch showed a N400 effect, in the masked and unmasked conditions.•Grammatical gender mismatch revealed a P300 effect, regardless of masking.•Gender ...stereotypes can strongly influence our behavior even under unconscious conditions.
The aim of this study was to explore the neural correlates of the automatic activation of gender stereotypes by using the masked and unmasked priming technique. Event-related potentials (ERPs) were recorded while participants were presented with an Italian third-person singular pronoun (lui or lei) that were preceded by either a grammatically-marked (e.g., passeggeraFEM, pensionatoMASC) or stereotypically-associated (e.g., insegnanteFEM, conducenteMASC) role noun. Participants were required to judge the grammatical gender of the personal pronoun ignoring the preceding word. This word was presented in a masked or unmasked way. The results revealed slower reaction times and larger N400, in both the masked and unmasked conditions, when the pronouns were preceded by gender-incongruent than gender-congruent grammatical and stereotypical primes. A P300 effect also emerged in both masked and unmasked conditions for the grammatical gender mismatch between the antecedent and the pronoun. These results provide evidence that gender stereotypes can strongly influence our behavior even under unconscious conditions.
The period–metallicity–K-band luminosity (PLK) relation for RR Lyrae stars in 15 Galactic globular clusters and in the Large Magellanic Cloud (LMC) globular cluster Reticulum has been derived. It is ...based on accurate near-infrared (K) photometry combined with Two-Micron All-Sky Survey (2MASS) and other literature data. The PLK relation has been calibrated and compared with the previous empirical and theoretical determinations in literature. The zero point of the absolute calibration has been obtained from the K magnitude of RR Lyr whose distance modulus has been measured via trigonometric parallax with Hubble Space Telescope (HST). Using this relation, we obtain a distance modulus to the LMC of (m−M)0= 18.54 ± 0.15 mag, in good agreement with recent determinations based on the analysis of Cepheid variable stars.
We have analysed a sample of 18 RR Lyrae stars (17 fundamental-mode -- RRab -- and one first overtone -- RRc) and three Population II Cepheids (two BL Her stars and one W Vir star), for which ...high-resolution (R greater than or equal to 30 000), high signal-to-noise (S/N greater than or equal to 30) spectra were obtained with either SARG at the Telescopio Nazionale Galileo (La Palma, Spain) or UVES at the European Southern Observatory Very Large Telescope (Paranal, Chile). Archival data were also analysed for a few stars, sampling greater than or equal to 3 phases for each star. We obtained atmospheric parameters (T sub(eff), log g, v sub(t), and M/H) and abundances of several iron-peak and alpha -elements (Fe, Cr, Ni, Mg, Ca, Si, and Ti) for different pulsational phases, obtaining < alpha /Fe> = +0.31 plus or minus 0.19 dex over the entire sample covering -2.2 < Fe/H < -1.1 dex. We find that silicon is indeed extremely sensitive to the phase, as reported by previous authors, and cannot be reliably determined. Apart from this, metallicities and abundance ratios are consistently determined, regardless of the phase, within 0.10-0.15 dex, although caution should be used in the range 0 less than or equal to phi less than or equal to 0.15. Our results agree with literature determinations for both variable and non-variable field stars, obtained with very different methods, including low- and high-resolution spectroscopy. W Vir and BL Her stars, at least in the sampled phases, appear indistinguishable from RRab from the spectroscopic analysis point of view. Our large sample, covering all pulsation phases, confirms that chemical abundances can be obtained for RR Lyrae with the classical equivalent-width -based technique and static model atmospheres, even rather close to the shock phases.
We identify 51 blue horizontal branch (BHB) stars, 12 possible BHB stars and 58 RR Lyrae stars in Anticentre fields. Their selection does not depend on their kinematics. Light curves and ephemerides ...are given for seven previously unknown RR Lyrae stars. All but four of the RR Lyrae stars are of Oosterhoff type I.
Our selection criteria for BHB stars give results that agree with those used by Smith et al. and Ruhland et al. We use five methods to determine distances for the BHB stars and three methods for the RR Lyrae stars to get distances on a uniform scale. Absolute proper motions largely derived from the Second Guide Star Catalogue (GSCII) and Sloan Digital Sky Survey (Seventh Data Release) data bases are given for these stars; radial velocities are given for 31 of the BHB stars and 37 of the RR Lyrae stars.
Combining these data for BHB and RR Lyrae stars with those previously found in fields at the North Galactic Pole, we find that retrograde orbits dominate for galactocentric distances greater than 12.5 kpc. The majority of metal-poor stars in the solar neighbourhood are known to be concentrated in a L
⊥ versus L
z
angular momentum plot. We show that the ratio of the number of outliers to the number in the main concentration increases with galactocentric distance. The location of these outliers with L
⊥ and L
z
shows that the halo BHB and RR Lyrae stars have more retrograde orbits and a more spherical distribution with increasing galactocentric distance. Six RR Lyrae stars are identified in the H99 group of outliers; the small spread in their Fe/H suggests that they could have come from a single globular cluster. Another group of outliers contains two pairs of RR Lyrae stars; the stars in each pair have similar properties.
Context. Multiple populations have been detected in several globular clusters (GC) that do not display a spread in metallicity. Unusual features of their observed colour–magnitude diagrams (CMD) can ...be interpreted in terms of differences in the helium content of the stars belonging to the sub-populations. Aims. Even if evidence gathered so far is compelling, differences in He abundance have never been directly observed. We attempt to measure these differences in two giant stars of NGC 2808 with very similar astrophysical parameters but different Na and O abundances, hence that presumably belong to different sub-populations, by directly comparing their He I 10 830 Å lines. Methods. The He 10 830 Å line forms in the upper chromosphere. Our detailed models derive the chromospheric structure using the Ca II and Hα chromospheric lines, and simulate the corresponding He I 10 830 line profiles as a function of the helium abundance. We show that, at a given value of He abundance, the He I 10 830 equivalent width cannot significantly change without a corresponding much larger change in the Ca II chromospheric lines. We have used the VLT-CRIRES to obtain high-resolution spectra in the 10 830 Å region, and the VLT-UVES to obtain spectra of the Ca II and Hα lines of our target stars. Results. The two target stars have very similar Ca II and Hα chromospheric lines, but different appearances in the He region. One line, blueshifted by 17 km s-1 with respect to the He 10 830 rest wavelength, is detected in the spectrum of the Na-rich star, whereas the Na-poor star spectrum is consistent with a non-detection. From a detailed chromospheric modeling, we show that the difference in the spectra is consistent and most closely explained by an He abundance difference between the two stars of ΔY ≥ 0.17. Our optical observations bracket the infrared ones over a range of about 50 days and we do not observe any substantial variability in the Ca II and Hα lines. Conclusions. We provide direct evidence of a significant He line strength difference in giant stars of NGC 2808 belonging to different sub-populations, which had been previously detected by other photometric and spectroscopic means. The use of appropriate model chromospheres allows us for the first time to provide an approximate quantitative estimate of this difference, which is clearly consistent with the expected difference in abundance required by the stellar evolution theory to account for the observed peculiarities of this cluster’s cmD.
Gaia Data Release 1 Carrasco, J M; Evans, D W; Montegriffo, P ...
Astronomy and astrophysics (Berlin),
11/2016, Letnik:
595
Journal Article
Recenzirano
Odprti dostop
Context. Gaia is an ESA cornerstone mission launched on 19 December 2013 aiming to obtain the most complete and precise 3D map of our Galaxy by observing more than one billion sources. This paper is ...part of a series of documents explaining the data processing and its results for Gaia Data Release 1, focussing on the G band photometry. Aims. This paper describes the calibration model of the Gaia photometric passband for Gaia Data Release 1. Methods. The overall principle of splitting the process into internal and external calibrations is outlined. In the internal calibration, a self-consistent photometric system is generated. Then, the external calibration provides the link to the absolute photometric flux scales. Results. The Gaia photometric calibration pipeline explained here was applied to the first data release with good results. Details are given of the various calibration elements including the mathematical formulation of the models used and of the extraction and preparation of the required input parameters (e.g. colour terms). The external calibration in this first release provides the absolute zero point and photometric transformations from the GaiaG passband to other common photometric systems. Conclusions. This paper describes the photometric calibration implemented for the first Gaia data release and the instrumental effects taken into account. For this first release no aperture losses, radiation damage, and other second-order effects have not yet been implemented in the calibration.
Gaia Data Release 1 Evans, D W; Riello, M; De Angeli, F ...
Astronomy and astrophysics (Berlin),
4/2017, Letnik:
600
Journal Article
Recenzirano
Aims. The photometric validation of the Gaia DR1 release of the ESA Gaia mission is described and the quality of the data shown. Methods. This is carried out via an internal analysis of the ...photometry using the most constant sources. Comparisons with external photometric catalogues are also made, but are limited by the accuracies and systematics present in these catalogues. An analysis of the quoted errors is also described. Investigations of the calibration coefficients reveal some of the systematic effects that affect the fluxes. Results. The analysis of the constant sources shows that the early-stage photometric calibrations can reach an accuracy as low as 3 mmag.
Gaia Data Release 2 Riello, M.; De Angeli, F.; Evans, D. W. ...
Astronomy & astrophysics,
08/2018, Letnik:
616
Journal Article
Recenzirano
Odprti dostop
Context. The second Gaia data release is based on 22 months of mission data with an average of 0.9 billion individual CCD observations per day. A data volume of this size and granularity requires a ...robust and reliable but still flexible system to achieve the demanding accuracy and precision constraints that Gaia is capable of delivering. Aims. We aim to describe the input data, the treatment of blue photometer/red photometer (BP/RP) low-resolution spectra required to produce the integrated GBP and GRP fluxes, the process used to establish the internal Gaia photometric system, and finally, the generation of the mean source photometry from the calibrated epoch data for Gaia DR2. Methods. The internal Gaia photometric system was initialised using an iterative process that is solely based on Gaia data. A set of calibrations was derived for the entire Gaia DR2 baseline and then used to produce the final mean source photometry. The photometric catalogue contains 2.5 billion sources comprised of three different grades depending on the availability of colour information and the procedure used to calibrate them: 1.5 billion gold, 144 million silver, and 0.9 billion bronze. These figures reflect the results of the photometric processing; the content of the data release will be different due to the validation and data quality filters applied during the catalogue preparation. The photometric processing pipeline, PhotPipe, implements all the processing and calibration workflows in terms of Map/Reduce jobs based on the Hadoop platform. This is the first example of a processing system for a large astrophysical survey project to make use of these technologies. Results. The improvements in the generation of the integrated G–band fluxes, in the attitude modelling, in the cross-matching, and and in the identification of spurious detections led to a much cleaner input stream for the photometric processing. This, combined with the improvements in the definition of the internal photometric system and calibration flow, produced high-quality photometry. Hadoop proved to be an excellent platform choice for the implementation of PhotPipe in terms of overall performance, scalability, downtime, and manpower required for operations and maintenance.
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