- ID:
- ivo://CDS.VizieR/J/MNRAS/444/2571
- Title:
- Early-Tyoe Galaxies in SDSS and GALEX
- Short Name:
- J/MNRAS/444/2571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the Hernandez-Perez and Bruzual stellar population synthesis models to study the role of interacting binary pairs as progenitors of extreme horizontal branch (EHB) stars. We assemble a sample of 3417 early-type galaxies observed both in the optical (SDSS-DR8) and the UV (GALEX-GR6). The galaxies in our sample can be classified according to their position in the colour-colour diagram as UV-weak or red-sequence galaxies (~48%), UV-strong or UVX galaxies (~9%), and recent star-forming galaxies (~43%). Analysing this sample using the models for various choices of basic model parameters, we conclude that (a) the UVr colours of UV-weak and UV-strong galaxies are reproduced by the models as long as the fraction of binary stars is at least 15%. (b) Higher metallicity models (Z=0.02 and 0.03) reproduce the colours of UV-weak and UV-strong galaxies better than lower Z models. The Z=0.03 model is slightly bluer than the Z=0.02 model in the UV-strong region, indicating a weak relationship between UVX and Z. (c) The strength of UVX increases with age in the model population. This is at variance with the results of other models that include binary stars as progenitors of EHB stars.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/796/60
- Title:
- ECDFS galaxies photometric redshifts & counterparts
- Short Name:
- J/ApJ/796/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4Ms CDFS and 250ks ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources (~96%). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time in this work. Photometric redshifts for X-ray source counterparts are based on a new library of active galactic nuclei/galaxy hybrid templates appropriate for the faint X-ray population in the CDFS. Photometric redshift accuracy for normal galaxies is 0.010 and for X-ray sources is 0.014 and outlier fractions are 4% and 5.2%, respectively. The results within the CANDELS coverage area are even better, as demonstrated both by spectroscopic comparison and by galaxy-pair statistics. Intermediate-band photometry, even if shallow, is valuable when combined with deep broadband photometry. For best accuracy, templates must include emission lines.
- ID:
- ivo://CDS.VizieR/J/ApJ/811/78
- Title:
- Elemental depletions in the Magellanic Clouds
- Short Name:
- J/ApJ/811/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC) using UV absorption spectroscopy. We measure PII and FeII along 84 spatially distributed sightlines toward the MCs using archival Far Ultraviolet Spectroscopic Explorer observations. For 16 of those sightlines, we also measure SiII, CrII, and ZnII from new Hubble Space Telescope Cosmic Origins Spectrograph observations. We analyze these spectra using a new spectral line analysis technique based on a semi-parametric Voigt profile model. We have combined these measurements with HI and H_2_ column densities and reference stellar abundances from the literature to derive gas-phase abundances, depletions, and gas-to-dust ratios (GDRs). Of our 84 P and 16 Zn measurements, 80 and 13, respectively, are depleted by more than 0.1dex, suggesting that P and Zn abundances are not accurate metallicity indicators at and above the metallicity of the SMC. Si, Cr, and Fe are systematically less depleted in the SMC than in the Milky Way (MW) or LMC. The minimum Si depletion in the SMC is consistent with zero. We find GDR ranges of 190-565 in the LMC and 480-2100 in the SMC, which is broadly consistent with GDRs from the literature. These ranges represent actual location to location variation and are evidence of dust destruction and/or growth in the diffuse neutral phase of the interstellar medium. Where they overlap in metallicity, the gas-phase abundances of the MW, LMC, and SMC and damped Ly{alpha} systems evolve similarly with metallicity.
- ID:
- ivo://CDS.VizieR/J/other/JAD/14.3
- Title:
- Emission lines in 32 Cygni
- Short Name:
- J/other/JAD/14.3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- I identify the profusion of emission lines seen in IUE spectra of 32 Cyg (K4-5 Ib+B6-7 IV-V) during total eclipse. With the exception of a very few weak lines, all of these are also seen in zeta Aur during its eclipse, and the stronger features appear in 31 Cyg. Seventy-four percent of these emission lines can be attributed to FeII. Few are intrisically weaker than gf~0.01. Other spectra definitely present are CII, NI, OI, SiII, MgII, SII, CrII, NiII, AlII, AlIII, FIII, SiIV, and CIV. No emission lines of the neutral metals, except for fluorescent FeI UV44, are unambiguously detected; specifically, lines of CI, SiI, or SI were not detected in the spectrum.
- ID:
- ivo://CDS.VizieR/J/A+A/419/215
- Title:
- Emission lines of Sr filament near {eta} Car
- Short Name:
- J/A+A/419/215
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained deep spectra from 1640 to 10100{AA} with the Space Telescope Imaging Spectrograph (STIS) of the strontium filament, a largely neutral emission nebulosity lying close to the very luminous star Eta Carinae and showing an uncommon spectrum. Over 600 emission lines, both permitted and forbidden, have been identified.
- ID:
- ivo://CDS.VizieR/J/ApJ/711/1236
- Title:
- Equivalent width of H_2_ from FUSE
- Short Name:
- J/ApJ/711/1236
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Far Ultraviolet Spectroscopic Explorer (FUSE) has allowed precise determinations of the column densities of molecular hydrogen (H_2_) in Galactic lines of sight with a wide range of pathlengths and extinction properties. However, survey studies of lines of sight with greater extinction have been mostly restricted to the low-J states (lower total angular momentum) in which most molecular hydrogen is observed. This paper presents a survey of column densities for the molecular hydrogen in states of greater rotational excitation (J>=2) in Galactic lines of sight with log N(H_2_)>~20. This study is comprehensive through the highest excited state detectable in each line of sight. J=5 is observed in every line of sight, and we detect J=7 in four lines of sight, J=8 in one line of sight, and vibrationally excited H_2_ in two lines of sight.
- ID:
- ivo://CDS.VizieR/J/ApJ/887/91
- Title:
- Equivalent widths of giants in the GC NGC3201
- Short Name:
- J/ApJ/887/91
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GCs) has investigated multiple stellar populations by means of the "chromosome map" (ChM) diagnostic tool that maximizes the separation between stars with different chemical compositions. One of the most challenging features revealed by ChM analysis is the apparent inhomogeneity among stars belonging to the first population, a phenomenon largely attributed to He variations. However, this explanation is not supported by uniformity in the p-capture elements of these stars. The HST survey has revealed that the GC NGC 3201 shows exceptionally wide coverage in the {Delta}_F275W,F814W_ parameter of the ChM. We present a chemical abundance analysis of 24 elements in 18 giants belonging to the first population of this GC and having a wide range in {Delta}_F275W,F814W_. As far as the p-capture elements are concerned, the chemical abundances are typical of first-generation (1G) stars, as expected from the location of our targets in the ChM. Based on radial velocities and chemical abundance arguments, we find that the three stars with the lowest {Delta}_F275W,F814W_ values are binary candidates. This suggests that at least those stars could be explained with binarity. These results are consistent with evidence inferred from multiband photometry that evolved blue stragglers (BSs) populate the bluest part of the 1G sequence in the ChM. The remaining 15 spectroscopic targets show a small range in the overall metallicity by ~0.10dex, with stars at higher {Delta}_F275W,F814W_ values having higher absolute abundances. We suggest that a small variation in metals and binarity governs the color spread of the 1G in the ChM and that evolved BSs contribute to the bluest tail of the 1G sequence.
- ID:
- ivo://CDS.VizieR/J/ApJ/613/129
- Title:
- Equivalent widths of QSOs
- Short Name:
- J/ApJ/613/129
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for variability in the equivalent widths (EWs) of narrow, associated (|{Delta}v|<=5000km/s) absorption lines found in the UV spectra of z<=1.5 quasars. The goal of this search was to use variability as a means of identifying absorption lines arising in gas that is intrinsic to the quasar central engine. We have compared archival Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra of quasars with recent spectra obtained as part of our own snapshot survey of the same objects with the Space Telescope Imaging Spectrograph (STIS). The intervals between observations are 4-10yr. We primarily focused on the C IV absorption lines, although we also studied other lines available in the same spectra (e.g., Ly{alpha}, N V, O VI).
- ID:
- ivo://CDS.VizieR/J/PASP/109/998
- Title:
- EUVE optical atlas
- Short Name:
- J/PASP/109/998
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Extreme Ultraviolet Explorer (EUVE) has been detecting EUV sources since its launch in June 1992. Positions of 540 sources have been made available to the community by the EUVE team. We have extracted 7'x7' images centered on these 540 EUVE sources from the Space Telescope Science Institute digitized sky archives. We present these images as mosaic finder charts to aid observers trying to identify EUVE sources, or to characterize known sources.
- ID:
- ivo://CDS.VizieR/J/A+A/624/A36
- Title:
- EUV irradiances of the quiet Sun
- Short Name:
- J/A+A/624/A36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We benchmark new atomic data against a selection of irradiances obtained from medium-resolution quiet-Sun spectra in the extreme ultraviolet (EUV), from 60 to 1040{AA}. We used as a baseline the irradiances measured during solar minimum on 2008 April 14 by the prototype (PEVE) of the Solar Dynamics Observatory Extreme ultraviolet Variability Experiment (EVE). We took into account some inconsistencies in the PEVE data, using flight EVE data and irradiances we obtained from Solar and Heliospheric Observatory (SoHO) Coronal Diagnostics Spectrometer (CDS) data. We performed a differential emission measure and find overall excellent agreement (to within the accuracy of the observations, about 20%) between predicted and measured irradiances in most cases, although we point out several problems with the currently available ion charge-state distributions. We used the photospheric chemical abundances of Asplund et al. (2009ARA&A..47..481A). The new atomic data are nearly complete in this spectral range for medium-resolution irradiance spectra. Finally, we used observations of the active Sun in 1969 to show that the composition of the solar corona up to 1MK is nearly photospheric in this case as well. Variations of a factor of 2 are present for higher-temperature plasma, which is emitted within active regions. These results are in excellent agreement with our previous findings.
