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Text is a vehicle to convey information that reflects the writer's linguistic style and communicative patterns. By studying these attributes, we can discover latent insights about the author and their underlying message. This article uses such an approach to better understand patent applications and their inventors. While prior research focuses on patent metadata, we employ machine learning and natural language processing to extract hidden information from the words in patent applications. Through these methods, we find that inventor gender can often be identified from textual attributes - even without knowing the inventor's name. This ability to discern gender through text suggests that anonymized patent examination - often proposed as a solution to mitigate disparities in patent grant rates - may not fully address gendered outcomes in securing a patent. Our study also investigates whether objective features of a patent application can predict if it will be granted. Using a classifier algorithm, we correctly predicted whether a patent was granted over 60% of the time. Further analysis emphasized that writing style - like vocabulary and sentence complexity - disproportionately influenced grant predictions relative to other attributes such as inventor gender and subject matter keywords. Lastly, we examine whether women disproportionately invent in technological areas with higher rejection rates. Using a clustering algorithm, applications were allocated into groups with related subject matter. We found that 85% of female-dominated clusters have abnormally high rejection rates, compared to only 45% for male-dominated groupings. These findings highlight complex interactions between textual choices, gender, and success in securing a patent. They also raise questions about whether current proposals will be sufficient to achieve gender equity and efficiency in the patent system.

Previous work on the abundances of C, O, Na, Mg, Si, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn in low-alpha (accreted) and high-alpha (in situ born) halo stars is extended to include the abundances of Sc, V, and Co, enabling us to study the nucleosynthesis of all iron-peak elements along with the lighter elements. The Sc, V, and Co abundances were determined from a 1D MARCS model-atmosphere analysis of equivalent widths of atomic lines in high signal-to-noise, high resolution spectra assuming local thermodynamic equilibrium (LTE). In addition, new 3D and/or non-LTE calculations were used to correct the 1D LTE abundances for several elements including consistent 3D non-LTE calculations for Mg. The two populations of accreted and in situ born stars are well separated in diagrams showing [Sc/Fe], [V/Fe], and [Co/Fe] as a function of [Fe/H]. The [X/Mg] versus [Mg/H] trends for high-alpha and low-alpha stars were used to determine the yields of core-collapse and Type Ia supernovae. The largest Type Ia contribution occurs for Cr, Mn, and Fe, whereas Cu is a pure core-collapse element. Sc, Ti, V, Co, Ni, and Zn represent intermediate cases. A comparison with yields calculated for supernova models shows poor agreement for the core-collapse yields. The Ia yields suggest that sub-Chandrasekhar-mass Type Ia supernovae provide a dominant contribution to the chemical evolution of the host galaxies of the low-alpha stars. A substructure in the abundances and kinematics of the low-alpha stars suggests that they arise from at least two different satellite accretion events, Gaia-Sausage-Enceladus and Thamnos., Comment: Accepted for publication in A&A. 12 pages, 4 tables, and 7 figures

G112-43/44, alias BD+00_2058 A and B, is a metal-poor ([Fe/H] = -1.3) wide-orbit binary star with extreme kinematics. We use high-precision determinations of the chemical compositions of 94 metal-poor dwarf stars in the solar neighbourhood to compare abundance ratios for G112-43/44 with ratios for stars having similar metallicity taking into account the effect of deviations from local thermodynamic equilibrium on the derived abundances, and Gaia EDR3 data are used to compare the kinematics. The abundances of the two components of G112-43/44 agree within 0.05 dex for nearly all elements, but there is a hint of a correlation of the difference in [X/H] with elemental condensation temperature, which may be due to planet-star interactions. The Mg/Fe, Si/Fe, Ca/Fe, and Ti/Fe ratios of G112-43/44 agree with the corresponding ratios for accreted (Gaia-Enceladus) stars, but Mn/Fe, Ni/Fe, Cu/Fe, and Zn/Fe are significantly enhanced. The kinematics show that G112-43/44 belongs to the Helmi streams in the solar neighbourhood and in view of this, we discuss if the abundance peculiarities of G112-43/44 can be explained by chemical enrichment from supernovae events in the progenitor dwarf galaxy of the Helmi streams. Interestingly, yields calculated for a helium shell detonation Type Ia supernova model can explain the enhancement of Mn/Fe, Ni/Fe, Cu/Fe, and Zn/Fe in G112-43/44 and three other alpha-poor stars in the Galactic halo, one of which have Helmi streams kinematics. The helium shell detonation model predicts, however, also enhanced abundance ratios of Ca/Fe, Ti/Fe, and Cr/Fe in disagreement with the observed ratios., Comment: Accepted for publication in A&A

We present Johnson-Kron-Cousins BVRI photometry of 228 candidate spectrophotometric standard stars for the external (absolute) flux calibration of Gaia data. The data were gathered as part of a ten-year observing campaign with the goal of building the external grid of flux standards for Gaia and we obtained absolute photometry, relative photometry for constancy monitoring, and spectrophotometry. Preliminary releases of the flux tables were used to calibrate the first two Gaia releases. This paper focuses on the imaging frames observed in good sky conditions (about 9100). The photometry will be used to validate the ground-based flux tables of the Gaia spectrophotometric standard stars and to correct the spectra obtained in non-perfectly photometric observing conditions for small zeropoint variations. The absolute photometry presented here is tied to the Landolt standard stars system to $\simeq$1 per cent or better, depending on the photometric band. Extensive comparisons with various literature sources show an overall $\simeq$1 per cent agreement, which appears to be the current limit in the accuracy of flux calibrations across various samples and techniques in the literature. The Gaia photometric precision is presently of the order of 0.1 per cent or better, thus various ideas for the improvement of photometric calibration accuracy are discussed., Comment: 15 pages, 10 figures. This is a pre-copyedited, author-produced PDF of an article accepted for publication in MNRAS following peer review. Corrected bibliographic details

We have revisited and updated the $uvby$ Str\"omgren colour and colour-index distributions of A, F and early G-type main sequence stars. For this aim, we selected 7054 dwarf stars along with 65 MK standard stars within the same spectral range but covering all luminosity classes. The standard stars were selected following the MK mandate strictly, using spectra taken at classification resolution recorded on photographic plates. We used the colours of these stars to determine the effective temperature and surface gravity. After correcting for systematic offsets using fundamental parameters and considering a few exceptions, we find an one-to-one correspondence, among MK spectral types, Str\"omgren photometry, and their associated physical properties. We have applied a principal component analysis to the mean Str\"omgren indices for dwarf stars complemented by MK standards for higher luminosity classes. We have used the projections to introduce three new photometric metaindices, namely SM1, SM2, and SM3. We have defined a 3D-box, which allowed us to segregate dwarf stars from bright giants and supergiant stars, with the aid of the metaindices. Two of the planes show that the projections of dwarfs and supergiants are ordered by temperature; however, the temperature dependence for the supergiants is not as well defined as for the dwarfs. Following the MK Process, we were able to form an automatic classifier. We present some applications and assigned synthetical spectral types. We suggest that our metaindices formalism allows the extension of Str\"omgren photometric outside its original mandate (i.e., later types), without requiring the introduction of additional photometric filters., Comment: 20 pages, 22 figures, 9 tables, accepted for publication in MNRAS

The 3D Galactic orbits of stars in the two groups G18-39 and G21-22 pertaining to the Galactic halo have been computed in a Galactic potential including a Galactic bar. The orbits have been related with the orbital structure of resonant orbits on the Galactic plane created by the bar component. We find that the majority of stars in both groups are trapped mainly by two resonant families already studied in a previous analysis. We show that the observed U--V velocity field of the stars in both groups can be naturally explained as a result of their trapping by these two resonant families, taking the angular rotation speed of the bar approximately in the interval 45--60 $\mathrm{km\,s^{-1}\,kpc^{-1}}$. This analysis may help to understand the identification of other known star groups as the possible result of the interactions produced by resonances on stars close to resonant families. For the two groups G18-39 and G21-22 we conclude that the majority of their stars are members of the supergroups of stars in the Galaxy trapped by two resonant families generated by the Galactic bar., Comment: 22 pages, 15 figures, 3 Tables, submitted to ApJ, comments welcome

We present the results of the short-term constancy monitoring of candidate Gaia Spectrophotometric Standard Stars (SPSS). We obtained time series of typically 1.24 hour - with sampling periods from 1-3 min to a few hours, depending on the case - to monitor the constancy of our candidate SPSS down to 10 mmag, as required for the calibration of Gaia photometric data. We monitored 162 out of a total of 212 SPSS candidates. The observing campaign started in 2006 and finished in 2015, using 143 observing nights on nine different instruments covering both hemispheres. Using differential photometry techniques, we built light curves with a typical precision of 4 mmag, depending on the data quality. As a result of our constancy assessment, 150 SPSS candidates were validated against short term variability, and only 12 were rejected because of variability including some widely used flux standards such as BD+174708, SA 105-448, 1740346, and HD 37725., Comment: 14 pages, 9 figures, 3 tables. Accepted for pubblication (MNRAS)

The Gaia SpectroPhotometric Standard Stars (SPSS) survey started in 2006, it was awarded almost 450 observing nights, and accumulated almost 100,000 raw data frames, with both photometric and spectroscopic observations. Such large observational effort requires careful, homogeneous, and automated data reduction and quality control procedures. In this paper, we quantitatively evaluate instrumental effects that might have a significant (i.e.,$\geq$1%) impact on the Gaia SPSS flux calibration. The measurements involve six different instruments, monitored over the eight years of observations dedicated to the Gaia flux standards campaigns: DOLORES@TNG in La Palma, EFOSC2@NTT and ROSS@REM in La Silla, CAFOS@2.2m in Calar Alto, BFOSC@Cassini in Loiano, and LaRuca@1.5m in San Pedro Martir. We examine and quantitatively evaluate the following effects: CCD linearity and shutter times, calibration frames stability, lamp flexures, second order contamination, light polarization, and fringing. We present methods to correct for the relevant effects, which can be applied to a wide range of observational projects at similar instruments., Comment: 16 pages, 13 figures, accepted for publication in Astron. Nachr

Abundances of C, O, and Fe are determined for F and G main-sequence stars in the solar neighborhood in order to study trends and systematic differences in the C/Fe, O/Fe, and C/O ratios for stellar populations. Carbon abundances are determined from the CI lines at 5052 and 5380 AA and oxygen abundances from the OI triplet at 7774 AA and the [OI] line at 6300 AA. MARCS model atmospheres are applied and non-LTE corrections for the OI triplet are included. Systematic differences between high- and low-alpha halo stars and between thin- and thick-disk stars are seen in the trends of [C/Fe] and [O/Fe]. The two halo populations and thick-disk stars show the same trend of [C/O] versus [O/H], whereas thin-disk stars are shifted to higher [C/O]. Furthermore, we find some evidence of higher C/O and C/Fe ratios in stars hosting planets than in stars for which no planets have been detected. The results suggest that C and O in both high- and low-alpha halo stars and in thick-disk stars are made mainly in massive stars, whereas thin-disk stars have an additional carbon contribution from low-mass AGB and massive stars of high metallicity causing a rising trend of C/O with increasing metallicity. However, the C/O ratio does not exceed 0.8, which seems to exclude formation of carbon planets if proto-planetary disks have the same composition as their parent stars., Comment: 13 pages, 15 figures, and 4 on-line tables. Accepted for publication in A&A

We describe two ground based observing campaigns aimed at building a grid of approximately 200 spectrophotometric standard stars (SPSS), with an internal ~1% precision and tied to Vega within ~3%, for the absolute flux calibration of data gathered by Gaia, the ESA astrometric mission. The criteria for the selection and a list of candidates are presented, together with a description of the survey strategy and the adopted data analysis methods. We also discuss a short list of notable rejected SPSS candidates and difficult cases, based on identification problems, literature discordant data, visual companions, and variability. In fact, all candidates are also monitored for constancy (within \pm5 mmag, approximately). In particular, we report on a CALSPEC standard, 1740346, that we found to be a delta Scuti variable during our short-term monitoring (1-2 h) campaign., Comment: 16 pages, 4 tables, 9 figures, accepted for publication by MNRAS on 20 July 2012

We investigate if there is a difference in the lithium abundances of stars belonging to two halo populations of F and G main-sequence stars previously found to differ in [alpha/Fe] for the metallicity range -1.4 < [Fe/H] < -0.7. Li abundances are derived from the LiI 6707.8 A line measured in high-resolution spectra using MARCS model atmospheres. Furthermore, masses of the stars are determined from the logTeff - logg diagram by interpolating between Yonsei-Yale evolutionary tracks. There is no significant systematic difference in the lithium abundances of high- and low-alpha halo stars. For the large majority of stars with masses 0.7 < M/M_sun < 0.9 and heavy-element mass fractions 0.001 < Z < 0.006, the Li abundance is well fitted by a relation A(Li) = a0 + a1 M + a2 Z + a3 M Z, where a0, a1, a2, and a3 are constants. Extrapolating this relation to Z = 0 leads to a Li abundance close to the primordial value predicted from standard Big Bang nucleosynthesis calculations and the WMAP baryon density. The relation, however, does not apply to stars with [Fe/H] < -1.5. We suggest that metal-rich halo stars were formed with a Li abundance close to the primordial value, and that lithium in their atmospheres has been depleted in time with an approximately linear dependence on stellar mass and Z. The lack of a systematic difference in the Li abundances of high- and low-alpha stars indicates that an environmental effect is not important for the destruction of lithium., Comment: 10 pages, 7 figures, accepted for publication in Astronomy and Astrophysics

Photometric data in the UBV(RI)c system have been acquired for 80 solar analog stars for which we have previously derived highly precise atmospheric parameters Teff, log g, and [Fe/H] using high resolution, high signal-to-noise ratio spectra. UBV and (RI)c data for 46 and 76 of these stars, respectively, are published for the first time. Combining our data with those from the literature, colors in the UBV(RI)c system, with ~0.01 mag precision, are now available for 112 solar analogs. Multiple linear regression is used to derive the solar colors from these photometric data and the spectroscopically derived Teff, log g, and [Fe/H] values. To minimize the impact of systematic errors in the model-dependent atmospheric parameters, we use only the data for the ten stars that most closely resemble our Sun, i.e., the solar twins, and derive the following solar colors: (B-V)=0.653+/-0.005, (U-B)=0.166+/-0.022, (V-R)=0.352+/-0.007, and (V-I)=0.702+/-0.010. These colors are consistent, within the 1 sigma errors, with those derived using the entire sample of 112 solar analogs. We also derive the solar colors using the relation between spectral line-depth ratios and observed stellar colors, i.e., with a completely model-independent approach, and without restricting the analysis to solar twins. We find: (B-V)=0.653+/-0.003, (U-B)=0.158+/-0.009, (V-R)=0.356+/-0.003, and (V-I)=0.701+/-0.003, in excellent agreement with the model-dependent analysis., Comment: ApJ, in press

The differences between the neutron-capture element abundances of halo stars are important to our understanding of the nucleosynthesis of elements heavier than the iron group. We present a detailed abundance analysis of carbon and twelve neutron-capture elements from Sr up to Pb for a peculiar halo star G24-25 with [Fe/H] = -1.4 in order to probe its origin. The equivalent widths of unblended lines are measured from high resolution NOT/FIES spectra and used to derive abundances based on Kurucz model atmospheres. In the case of CH, Pr, Eu, Gd, and Pb lines, the abundances are derived by fitting synthetic profiles to the observed spectra. Abundance analyses are performed both relative to the Sun and to a normal halo star G16-20 that has similar stellar parameters as G24-25. We find that G24-25 is a halo subgiant star with an unseen component. It has large overabundances of carbon and heavy s-process elements and mild overabundances of Eu and light s-process elements. This abundance distribution is consistent with that of a typical CH giant. The abundance pattern can be explained by mass transfer from a former asymptotic giant branch component, which is now a white dwarf., Comment: 11 pages, 9 figures, accepted for publication in A&A

On the basis of a recently derived color-metallicity relation and stellar parameters from the Sloan Digtal Sky Survey Data Release 7 spectroscopic survey, a large sample of red horizontal branch candidates have been selected to serve as standard candles. The metallicity and kinematic distributions of these stars indicate that they mainly originate from the thick-disk and the halo populations. The typical thick disk is characterized by the first group peaking at [Fe/H] ~ -0.6, Vrot ~ 170 km/s with a vertical scale height around |Z| ~ 1.2 kpc, while stars with [Fe/H] < -0.9 are dominated by the halo population. Two sub-populations of the halo are suggested by the RHB stars peaking at [Fe/H] ~-1.3: one component with Vrot > 0 km/s (Halo I) shows a sign of metallicity gradient in the [Fe/H] versus |Z| diagram, while the other with Vrot < 0 km/s (Halo II) does not. The Halo I mainly clumps at the inner halo with R < 10 kpc and the Halo II comes both from the inner halo with R < 10 kpc and the outer halo with R > 10 kpc based on the star distribution in the R versus |Z| diagram., Comment: 10 pages, 15 figures

Solar colors have been determined on the uvby-$\beta$ photometric system to test absolute solar fluxes, to examine colors predicted by model atmospheres as a function of stellar parameters (Teff, log g, [Fe/H]), and to probe zero-points of Teff and metallicity scales. New uvby-$\beta$ photometry is presented for 73 solar-twin candidates. Most stars of our sample have also been observed spectroscopically to obtain accurate stellar parameters. Using the stars that most closely resemble the Sun, and complementing our data with photometry available in the literature, the solar colors on the uvby-$\beta$ system have been inferred. Our solar colors are compared with synthetic solar colors computed from absolute solar spectra and from the latest Kurucz (ATLAS9) and MARCS model atmospheres. The zero-points of different Teff and metallicity scales are verified and corrections are proposed. The Teff calibration of Alonso and collaborators has the poorest performance (~140 K off), while the relation of Casagrande et al. (2010) is the most accurate (within 10 K). We confirm that the Ramirez & Melendez (2005) uvby metallicity calibration, recommended by \'Arnad\'ottir et al. (2010) to obtain [Fe/H] in F, G, and K dwarfs, needs a small (~10%) zero-point correction to place the stars and the Sun on the same metallicity scale. Finally, we confirm that the c_1 index in solar analogs has a strong metallicity sensitivity., Comment: A&A, in press

The results of an observational campaign on the new $\delta$ Scuti pulsator \astrobj{HD~207331} are reported. The star was observed photometrically from August 26 to September 2, 2009 from the Observatorio San Pedro M\'artir (0.84-m telescope, Mexico) and the Observatorio del Teide (0.80-m telescope, Spain). An overall run of 53.8 h of useful data was collected from the two sites. Four oscillation frequencies for \astrobj{HD~207331} have been found above a 99\% confidence level. These results confirm the multiperiodic pulsation nature of the star suggested in previous observations with sparse data. Spectroscopic observations carried out in 2009 allowed us to derive its spectral type and luminosity class as well as to estimate its rotation rate. A simple comparison with models is performed., Comment: 6 pages, 5 figures, 3 tables, New Astronomy 15 (2010) 712-716

Preliminary results on the discovery and follow-up observations of a new $\delta$ Scuti pulsator in the Cygnus field are presented. The variability of the star HD 207331 was detected while testing a Str\"omgren spectrophotometer attached to the H.L. Johnson 1.5-m telescope at the San Pedro M\'artir observatory, M\'exico. CCD photometric data acquired soon after confirmed its variability. A few hours of $uvby$ differential photoelectric photometry during three nights revealed at least two beating periods. A two-site observational campaign carried out during one week in 2009 confirms the multi-periodic nature of this new $\delta$ Scuti pulsator., Comment: 4 pages, 3 figures, 4 tables, Astronomische Nachrichten, Proceedings of the HELAS IV Conference: Seismological Challenges for Stellar Structure, held in Lanzarote, Spain, February 2010, Astronomische Nachrichten, 331, No.9-10 (2010)/P37

We present Li abundances for 73 stars in the metallicity range -3.5 < [Fe/H] < -1.0 using improved IRFM temperatures (Casagrande et al. 2010) with precise E(B-V) values obtained mostly from interstellar NaI D lines, and high-quality equivalent widths (errors ~ 3%). At all metallicities we uncover a fine-structure in the Li abundances of Spite plateau stars, which we trace to Li depletion that depends on both metallicity and mass. Models including atomic diffusion and turbulent mixing seem to reproduce the observed Li depletion assuming a primordial Li abundance ALi = 2.64 dex (MARCS models) or 2.72 (Kurucz overshooting models), in good agreement with current predictions (ALi = 2.72) from standard BBN. We are currently expanding our sample to have a better coverage of different evolutionary stages at the high and low metallicity ends, in order to verify our findings., Comment: In press, Light elements in the Universe, Proceedings IAU Symposium No. 268, 2010. C. Charbonnel, M. Tosi, F. Primas & C. Chiappini, eds

The three open clusters Be 15, Be 80, and NGC 2192 have been observed using CCD UBV(RI)_C photometry at the San Pedro M\'artir Observatory, M\'exico within the framework of our open-cluster survey. The fundamental parameters of interstellar reddening, distance, and age have been derived, and also the metallicity for NGC 2192 (solar metallicity has been assumed for the other two). By shifting the colours of Schmidt-Kaler in the (U-B, B-V) two-colour diagram along the appropriate reddening vector, the interstellar reddenings have been derived as E(B-V)=0.23+/-0.03 mag for Be 15, 1.31+/-0.05 for Be 80, and 0.16+/-0.03 for NGC 2192. Evidence is shown for a variable interstellar extinction across the cluster Be 80. For NGC 2192 a nicely consistent fit is obtained for both the interstellar reddening and the metallicity ([Fe/H]=-0.31) using simultaneously the F-type and red-clump stars. By fitting isochrones to the observed sequences of these three clusters in various colour-magnitude diagrams of different colour indices, (B-V, V-I, or V-R) the averages of distance moduli and heliocentric distances ((V-M_V)_o (mag); d(pc)) are the following: (10.74+/-0.01; 1202) for Be 15, (10.75+/-0.01; 1413) for Be 80, and (12.7+/-0.01; 3467) for NGC 2192, and the averages of the inferred best ages (log(age); age (Gyr)) are (8.6+/-0.05; 0.4) for Be 80, and (9.15+/-0.05; 1.4) for NGC 2192; for Be 15 there are two distinct possibilities for the age fit, depending on the membership of three brighter stars, (9.35 or 9.95+/-0.05; 2.2 or 8.9). The need for spectroscopic observations in Be 15 is emphasized to select between alternate reddening and age solutions, and for deeper UBV observations in Be 80 to study in greater detail the variable interstellar, or intracluster, reddening across this cluster., Comment: 13 pages, 13 encapsulated Postscript figures, 4 tables, to be published in MNRAS

While testing a Stromgren spectrophotometer attached to the 1.5-m telescope at the San Pedro Martir observatory, Mexico, a number of A-type stars were observed, one of which, HD 207331, presented clear indications of photometric variability. CCD photometric data acquired soon after, confirmed its variability. In order to determine its pulsation behaviour more accurately, uvby differential photoelectric photometry was carried out for three nights. As a result of the period analysis of the light curves we have found a dominant pulsation mode at 21.1 c/d with an amplitude of 6 mmag. This strongly suggests that HD 207331 is a new Delta Scuti-type pulsating star., Comment: 8 pages, 4 figures, 2 tables; accepted for publication in Communications in Asteroseismology

New uvby-\beta data are provided for 442 high-velocity and metal-poor stars; 90 of these stars have been observed previously by us, and 352 are new. When combined with our previous two photometric catalogues, the data base is now made up of 1533 high-velocity and metal-poor stars, all with uvby-\beta photometry and complete kinematic data, such as proper motions and radial velocities taken from the literature. Hipparcos, plus a new photometric calibration for M_v also based on the Hipparcos parallaxes, provide distances for nearly all of these stars; our previous photometric calibrations give values for E(b-y) and [Fe/H]. The [Fe/H],V(rot) diagram allows us to separate these stars into different Galactic stellar population groups, such as old-thin-disk, thick-disk, and halo. The X histogram, where X is our stellar-population discriminator combining V(rot) and [Fe/H], and contour plots for the [Fe/H],V(rot) diagram both indicate two probable components to the thick disk. These population groups and Galactic components are studied in the (b-y)_o,M_v diagram, compared to the isochrones of Bergbusch & VandenBerg (2001), to derive stellar ages. The two thick-disk groups have the mean characteristics: ([Fe/H], V(rot), Age, \sigma_W') ~ (-0.7 dex, 120 km/s, 12.5 Gyr, 62.0 km/s), and ~(-0.4, 160, 10.0, 45.8). The seven most metal-poor halo groups, -2.31 <= [Fe/H] <= -1.31, show a mean age of 13.0 +/-0.2 (mean error) Gyr, giving a mean difference from the WMAP results for the age of the Universe of 0.7 +/- 0.3 Gyr. These results for the ages and components of the thick disk and for the age of the Galactic halo field stars are discussed in terms of various models and ideas for the formation of galaxies and their stellar populations., Comment: To be published in A&A, 24 pages with 13 figures. Paper X of series: astro-ph/0403637

A new metallicity distribution and an age-metallicity relation are presented for 437 nearby F and G turn-off and sub-giant stars selected from radial velocity data of Nidever et al. Photometric metallicities are derived from uvby-H\beta photometry, and the stellar ages from the isochrones of Bergbusch & VandenBerg as transformed to $uvby$ photometry using the methods of Clem et al. The X (stellar-population) criterion of Schuster et al., which combines both kinematic and metallicity information, provides 22 thick-disk stars. \sigma_{\rm W} = 32 \pm 5 km s^{-1}, = 154 \pm 6 km s^{-1} and <[M/H]> = -0.55 \pm 0.03 dex for these thick-disk stars, which is in agreement with values from previous studies of the thick disk. \alpha -element abundances which are available for some of these thick-disk stars show the typical alpha-element signatures of the thick disk, supporting the classification procedure based on the $X$ criteria. Both the scatter in metallicity at a given age and the presence of old, metal-rich stars in the age-metallicity relation make it difficult to decide whether or not an age-metallicity relation exists for the older thin-disk stars. For ages greater than 3 Gyr, our results agree with the other recent studies that there is almost no correlation between age and metallicity, \Delta ([M/Fe])/\Delta(age) = -0.01 \pm 0.005 dex Gyr^{-1}. For the 22 thick-disk stars there is a range in ages of 7-8 Gyr, but again almost no correlation between age and metallicity., Comment: 11 pages, including 10 figures and 3 tables, accepted for publication in MNRAS

uvby(--$\beta$) photometry has been obtained for an additional 411 very metal-poor stars selected from the HK survey, and used to derive basic parameters such as interstellar reddenings, metallicities, photometric classifications, distances, and relative ages... These very metal-poor stars are compared to M92 in the c_0,(b-y)_0 diagram, and evidence is seen for field stars 1-3 Gyrs younger than this globular cluster. The significance of these younger very metal-poor stars is discussed in the context of Galactic evolution, mentioning such possibilities as hierarchical star-formation/mass-infall of very metal-poor material and/or accretion events whereby this material has been acquired from other (dwarf) galaxies with different formation and chemical-enrichment histories, Comment: 20 pages, 11 figures, and 9 tables

Sc and Mn abundances are determined for 119 F and G main-sequence stars with -1.4 < [Fe/H] < +0.1, representing stars from the thin disk, the thick disk and the halo. The results indicate that Sc behaves like an alpha-element, showing a decreasing [Sc/Fe] with increasing metallicity in disk stars and a dual pattern in the kinematically selected halo stars. In contrast, Mn shows an increase from [Mn/Fe] = -0.5 at [Fe/H] = -1.4 to zero at solar metallicity. There appears to be a discontinuity or sharp increase of [Mn/Fe] at [Fe/H] = -0.7 corresponding to the transition between the thick and the thin disk. It is discussed if supernovae of Type Ia are a major source of Mn in the Galactic disk or if the trend of [Mn/Fe] vs. [Fe/H] can be explained by nucleosynthesis in Type II supernovae with a strong metallicity dependence of the yield., Comment: 9 pages with 2 figures. Acepted for publication in A&A