- ID:
- ivo://CDS.VizieR/J/ApJ/765/140
- Title:
- Stacked spectra of SDSS star forming galaxies
- Short Name:
- J/ApJ/765/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between galaxy stellar mass and gas-phase metallicity is a sensitive diagnostic of the main processes that drive galaxy evolution, namely cosmological gas inflow, metal production in stars, and gas outflow via galactic winds. We employed the direct method to measure the metallicities of ~200000 star-forming galaxies from the Sloan Digital Sky Survey that were stacked in bins of (1) stellar mass and (2) both stellar mass and star formation rate (SFR) to significantly enhance the signal-to-noise ratio of the weak [OIII]{lambda}4363 and [OII]{lambda}{lambda}7320,7330 auroral lines required to apply the direct method. These metallicity measurements span three decades in stellar mass from log(M_*_/M_{sun}_)=7.4-10.5, which allows the direct method mass-metallicity relation to simultaneously capture the high-mass turnover and extend a full decade lower in mass than previous studies that employed more uncertain strong line methods. The direct method mass-metallicity relation rises steeply at low mass (O/H{prop.to}M_*_^1/2^) until it turns over at log(M_*_/M_{sun}_)=8.9 and asymptotes to 12+log(O/H)=8.8 at high mass. The direct method mass-metallicity relation has a steeper slope, a lower turnover mass, and a factor of two to three greater dependence on SFR than strong line mass-metallicity relations. Furthermore, the SFR-dependence appears monotonic with stellar mass, unlike strong line mass-metallicity relations. We also measure the N/O abundance ratio, an important tracer of star formation history, and find the clear signature of primary and secondary nitrogen enrichment. N/O correlates tightly with oxygen abundance, and even more so with stellar mass.
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17732. STAGES master catalog
- ID:
- ivo://CDS.VizieR/J/MNRAS/393/1275
- Title:
- STAGES master catalog
- Short Name:
- J/MNRAS/393/1275
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an overview of the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). STAGES is a multiwavelength project designed to probe physical drivers of galaxy evolution across a wide range of environments and luminosity. A complex multicluster system at z~0.165 has been the subject of an 80-orbit F606W Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) mosaic covering the full 0.5x0.5deg^2^ (~5x5Mpc^2^) span of the supercluster. Extensive multiwavelength observations with XMM-Newton, GALEX, Spitzer, 2dF, Giant Metrewave Radio Telescope and the 17-band COMBO-17 photometric redshift survey complement the HST imaging. Our survey goals include simultaneously linking galaxy morphology with other observables such as age, star formation rate, nuclear activity and stellar mass. In addition, with the multiwavelength data set and new high-resolution mass maps from gravitational lensing, we are able to disentangle the large-scale structure of the system. By examining all aspects of an environment we will be able to evaluate the relative importance of the dark matter haloes, the local galaxy density and the hot X-ray gas in driving galaxy transformation.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A26
- Title:
- STAGGER-grid of 3D stellar models. I.
- Short Name:
- J/A+A/557/A26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the STAGGER-grid, a comprehensive grid of time-dependent, three-dimensional (3D), hydrodynamic model atmospheres for late-type stars with realistic treatment of radiative transfer, covering a wide range in stellar parameters. All our models were generated with the Stagger-code, using realistic input physics for the equation of state (EOS) and for continuous and line opacities. Our ~220 grid models range in effective temperature, Teff, from 4000 to 7000K in steps of 500K, in surface gravity, logg, from 1.5 to 5.0 in steps of 0.5dex, and metallicity, [Fe/H], from -4.0 to +0.5 in steps of 0.5 and 1.0dex.
- ID:
- ivo://CDS.VizieR/J/A+A/560/A8
- Title:
- STAGGER-grid of 3D stellar models. II.
- Short Name:
- J/A+A/560/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the implications of averaging methods with different reference depth scales for 3D hydrodynamical model atmospheres computed with the Stagger-code. The temporally and spatially averaged (hereafter denoted as <3D>) models are explored in the light of local thermodynamic equilibrium (LTE) spectral line formation by comparing spectrum calculations using full 3D atmosphere structures with those from <3D> averages. We explored methods for computing mean <3D> stratifications from the Stagger-grid time-dependent 3D radiative hydrodynamical atmosphere models by considering four different reference depth scales (geometrical depth, column-mass density, and two optical depth scales). Furthermore, we investigated the influence of alternative averages (logarithmic, enforced hydrostatic equilibrium, flux-weighted temperatures). For the line formation we computed curves of growth for FeI and FeII lines in LTE.
- ID:
- ivo://CDS.VizieR/J/A+A/573/A89
- Title:
- STAGGER-grid of 3D stellar models. III.
- Short Name:
- J/A+A/573/A89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the relation between 1D atmosphere models that rely on the mixing length theory and models based on full 3D radiative hydrodynamic (RHD) calculations to describe convection in the envelopes of late-type stars. The adiabatic entropy value of the deep convection zone, s_bot_, and the entropy jump, {Delta}s, determined from the 3D RHD models, are matched with the mixing length parameter, {alpha}_MLT_, from 1D hydrostatic atmosphere models with identical microphysics (opacities and equation-of-state). We also derive the mass mixing length, {alpha}_m_, and the vertical correlation length of the vertical velocity, C[V_z_,V_z_], directly from the 3D hydrodynamical simulations of stellar subsurface convection.
- ID:
- ivo://CDS.VizieR/J/A+A/573/A90
- Title:
- STAGGER-grid of 3D stellar models. IV.
- Short Name:
- J/A+A/573/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compute the emergent stellar spectra from the UV to far infrared for different viewing angles using realistic 3D model atmospheres for a large range in stellar parameters to predict the stellar limb darkening. We have computed full 3D LTE synthetic spectra based on 3D radiative hydrodynamic atmosphere models from the Stagger-grid in the ranges: Teff from 4000 to 7000K, logg from 1.5 to 5.0, and [Fe/H], from -4.0 to +0.5. From the resulting intensities at different wavelength, we derived coefficients for the standard limb darkening laws considering a number of often-used photometric filters. Furthermore, we calculated theoretical transit light curves, in order to quantify the differences between predictions by the widely used 1D model atmosphere and our 3D models.
- ID:
- ivo://CDS.VizieR/J/A+A/611/A11
- Title:
- STAGGER-grid of 3D stellar models. V.
- Short Name:
- J/A+A/611/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have calculated spectra from 1000 to 200000{AA} with a constant resolving power of {lambda}/{Delta}{lambda}=20000 and from 8470 and 8710{AA} (Gaia Radial Velocity Spectrometer - RVS - spectral range) with a constant resolving power of {lambda}/{Delta}{lambda}=300000. This for the Stagger-grid 3D stellar atmosphere models in the ranges: Teff from 4000 to 7000K, logg from 1.5 to 5.0, and [Fe/H], from -4.0 to +0.5. We used synthetic spectra to compute theoretical colours in the Johnson-Cousins UBV(RI)C, SDSS, 2MASS, Gaia, SkyMap- per, Stroemgren systems, and HST-WFC3.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A153
- Title:
- Staked SEDs and templates of LBGs at z~3
- Short Name:
- J/A+A/630/A153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We explore, from a statistical point of view, the rest-frame far-ultraviolet (FUV) to far-infrared (FIR) emission of a population of Lyman-break galaxies (LBGs) at z~3 that cannot be individually detected from current FIR observations. We performed a stacking analysis over a sample of ~17000 LBGs at redshift 2.5<z<3.5 in the COSMOS field. The sample is binned as a function of UV luminosity (L_FUV_), UV continuum slope (beta_UV_), and stellar mass (M*), and then stacked at optical (BVriz bands), near-infrared (YJHKs bands), IRAC (3.6, 4.5, 5.6 and 8.0um), MIPS (24um), PACS (100 and 160 um), SPIRE (250, 350, and 500um), and AzTEC (1.1mm) observations. We obtained 30 rest-frame FUV-to-FIR spectral energy distributions (SEDs) of LBGs at z~3, and analyzed these with the CIGALE SED-fitting analysis code. We were able to derive fully consistent physical parameters, that is, M*, beta_UV_, L_FUV_, L_IR_, A_FUV_, star formation rate, and the slope of the dust attenuation law; we built a semiempirical library of 30 rest-frame FUV-to-FIR stacked LBG SEDs as functions of L_FUV_, beta_UV_, and M*. Additionally, We used the so-called IR-excess (IRX) to investigate the dust attenuation and the shape of the dust attenuation curve as a function of L_UV_, beta_UV_ and M*.
- ID:
- ivo://CDS.VizieR/J/AJ/132/1445
- Title:
- Standard calibration stars infrared spectra
- Short Name:
- J/AJ/132/1445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Infrared spectra with increased spectral resolution and accuracy of the absolute infrared spectral flux have been created for a subset of stellar standards created by Cohen and his collaborators in previous papers in this series. Moderate-resolution ({lambda}/{Delta}{lambda}~400) spectroscopy obtained on infrared standard stars by the Short Wavelength Spectrometer on the Infrared Space Observatory was combined with high-quality photometry tied to our recent absolute calibration from the Midcourse Space Experiment. Thus, 1-35 micron spectra were created for 33 stars, 9 of which are Cohen et al. secondary standards and another 20 of which are tertiary standards for which Cohen adopted spectral templates. The wavelength spacing is given by (0.0001/1 micron)*lambda^2, which provides for 10,000 samples over the 1-35 micron spectral range
- ID:
- ivo://CDS.VizieR/J/other/RoAJ/10.51
- Title:
- Standard errors for PPM and Tycho stars
- Short Name:
- J/other/RoAJ/10.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The connection between the optical reference frame and the radio one constitutes one of the main purposes of the astrometry. The paper is pointing out the contribution of the Bucharest Observatory in this direction. The statistic analysis of the standard errors for the astrometric PPM and TYCHO stars is presented.