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14211. Spectroscopy of HII regions in nearby galaxies
ID:
ivo://CDS.VizieR/J/A+A/546/A2
Title:
Spectroscopy of HII regions in nearby galaxies
Short Name:
J/A+A/546/A2
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work we analyze the spectroscopic properties of a large number of HII regions, ~2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on spirals in the PINGS survey and a sample described in Marmol-Queralto (2011A&A...534A...8M). All the galaxies were observed using Integral Field Spectroscopy with a similar setup, covering their optical extension up to ~2.4 effective radii within a wavelength range from ~3700 to ~6900{AA}. We develop a new automatic procedure to detect HII regions, based on the contrast of the H{alpha} intensity maps extracted from the datacubes. Once detected, the procedure provides us with the integrated spectra of each individual segmented region. In total, we derive good quality spectroscopic information for ~2600 independent HII regions/complexes. This is by far the largest nearby 2-dimensional spectroscopic survey presented on this kind of regions up-to-date. Even more, our selection criteria and dataset guarantee that we cover the regions in an unbiased way, regarding the spatial sampling. A well-tested automatic decoupling procedure has been applied to remove the underlying stellar population, deriving the main properties (intensity, dispersion and velocity) of the strongest emission lines in the considered wavelength range (covering from [OII]3727 to [SII]6731). A final catalogue of the spectroscopic properties of these regions has been created for each galaxy.
14212. Spectroscopy of hot stars in the halo. III
ID:
ivo://CDS.VizieR/J/AJ/117/2329
Title:
Spectroscopy of hot stars in the halo. III
Short Name:
J/AJ/117/2329
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from an analysis of medium-resolution spectroscopy and UBV photometry for a sample of 1121 A-type stars in the halo (and disk) of the Galaxy. A previously developed calibration technique is used to assign estimates of effective temperature, surface gravity, and stellar metal abundance, as parametrized by [Fe/H]. Radial velocities are reported with an accuracy of {~}10 km.s^-1^. Distance estimates are obtained for the stars with well-determined luminosity classes. Note that although we refer to "A-type" stars, which dominate the present sample, the present data set includes roughly 100 stars of later spectral types, as a result of the temperature range we have chosen to explore in this paper (6000 K {<=} T_eff_ {<=} 10,000 K).
14213. Spectroscopy of 39 IRAS 1Jy sample ULIRG
ID:
ivo://CDS.VizieR/J/ApJS/203/3
Title:
Spectroscopy of 39 IRAS 1Jy sample ULIRG
Short Name:
J/ApJS/203/3
Date:
21 Oct 2021
Publisher:
CDS
Description:
Emission-line spectra extracted at multiple locations across 39 ultraluminous infrared galaxies have been compiled into a spectrophotometric atlas. Line profiles of H{alpha}, [NII], [SII], [OI], H{beta}, and [OIII] are resolved and fit jointly with common velocity components. Diagnostic ratios of these line fluxes are presented in a series of plots, showing how the Doppler shift, line width, gas excitation, and surface brightness change with velocity at fixed position and also with distance from the nucleus. One general characteristic of these spectra is the presence of shocked gas extending many kiloparsecs from the nucleus. In some systems, the rotation curves of the emitting gas indicate motions that suggest gas disks, which are most frequent at early merger stages. At these early merger stages, the emission line ratios indicate the presence of shocked gas, which may be triggered by the merger event. We also report the general characteristics of the integrated spectra.
14214. Spectroscopy of 64 K red giants
ID:
ivo://CDS.VizieR/J/ApJ/735/L46
Title:
Spectroscopy of 64 K red giants
Short Name:
J/ApJ/735/L46
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on high-resolution spectra obtained with the MIKE spectrograph on the Magellan telescopes, we present detailed elemental abundances for 20 red giant stars in the outer Galactic disk, located at Galactocentric distances between 9 and 13kpc. The outer disk sample is complemented with samples of red giants from the inner Galactic disk and the solar neighborhood, analyzed using identical methods. For Galactocentric distances beyond 10kpc, we only find chemical patterns associated with the local thin disk, even for stars far above the Galactic plane. Our results show that the relative densities of the thick and thin disks are dramatically different from the solar neighborhood, and we therefore suggest that the radial scale length of the thick disk is much shorter than that of the thin disk. We make a first estimate of the thick disk scale length of L_thick_=2.0kpc, assuming L_thin_=3.8kpc for the thin disk. We suggest that radial migration may explain the lack of radial age, metallicity, and abundance gradients in the thick disk, possibly also explaining the link between the thick disk and the metal-poor bulge.
14215. Spectroscopy of 26 lensing cluster cores
ID:
ivo://CDS.VizieR/J/ApJS/193/8
Title:
Spectroscopy of 26 lensing cluster cores
Short Name:
J/ApJS/193/8
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from a spectroscopic program targeting 26 strong-lensing cluster cores that were visually identified in the Sloan Digital Sky Survey (SDSS; Gladders et al. 2011, in prep) and the Second Red-Sequence Cluster Survey (RCS-2; Bayliss et al. 2011, in prep). The 26 galaxy cluster lenses span a redshift range of 0.2<z<0.65, and our spectroscopy reveals 69 unique background sources with redshifts as high as z=5.200. We also identify redshifts for 262 cluster member galaxies and measure the velocity dispersions and dynamical masses for 18 clusters where we have redshifts for N>=10 cluster member galaxies. We account for the expected biases in dynamical masses of strong-lensing-selected clusters as predicted by results from numerical simulations and discuss possible sources of bias in our observations.
14216. Spectroscopy of Leo I red giants
ID:
ivo://CDS.VizieR/J/ApJ/657/241
Title:
Spectroscopy of Leo I red giants
Short Name:
J/ApJ/657/241
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present low-resolution spectroscopy of 120 red giants in the Galactic satellite dwarf spheroidal (dSph) Leo I, obtained with GeminiN GMOS and Keck DEIMOS. We find stars with velocities consistent with membership of Leo I out to 1.3 King tidal radii. By measuring accurate radial velocities with a median measurement error of 4.6km/s, we find a mean systemic velocity of 284.2km/s with a global velocity dispersion of 9.9km/s. The dispersion profile is consistent with being flat out to the last data point.
14217. Spectroscopy of 6 LMC RR Lyrae and 3 SMC RR Lyrae
ID:
ivo://CDS.VizieR/J/AJ/144/88
Title:
Spectroscopy of 6 LMC RR Lyrae and 3 SMC RR Lyrae
Short Name:
J/AJ/144/88
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present for the first time a detailed spectroscopic study of chemical element abundances of metal-poor RR Lyrae stars in the Large and Small Magellanic Cloud (LMC and SMC). Using the MagE echelle spectrograph at the 6.5m Magellan telescopes, we obtain medium resolution (R~2000-6000) spectra of six RR Lyrae stars in the LMC and three RR Lyrae stars in the SMC. These stars were chosen because their previously determined photometric metallicities were among the lowest metallicities found for stars belonging to the old populations in the Magellanic Clouds. We find the spectroscopic metallicities of these stars to be as low as [Fe/H]_spec_=-2.7dex, the lowest metallicity yet measured for any star in the Magellanic Clouds. We confirm that for metal-poor stars, the photometric metallicities from the Fourier decomposition of the light curves are systematically too high compared to their spectroscopic counterparts. However, for even more metal-poor stars below [Fe/H]_phot_<-2.8dex this trend is reversed and the spectroscopic metallicities are systematically higher than the photometric estimates. We are able to determine abundance ratios for 10 chemical elements (Fe, Na, Mg, Al, Ca, Sc, Ti, Cr, Sr, and Ba), which extend the abundance measurements of chemical elements for RR Lyrae stars in the Clouds beyond [Fe/H] for the first time. For the overall [{alpha}/Fe] ratio, we obtain an overabundance of 0.36dex, which is in very good agreement with results from metal-poor stars in the Milky Way halo as well as from the metal-poor tail in dwarf spheroidal galaxies. Comparing the abundances with those of the stars in the Milky Way halo we find that the abundance ratios of stars of both populations are consistent with another. Therefore, we conclude that from a chemical point of view early contributions from Magellanic-type galaxies to the formation of the Galactic halo as claimed in cosmological models are plausible.
14218. Spectroscopy of low-metallicity star candidates
ID:
ivo://CDS.VizieR/J/ApJ/870/122
Title:
Spectroscopy of low-metallicity star candidates
Short Name:
J/ApJ/870/122
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from an observing campaign to identify low-metallicity stars in the Best & Brightest Survey. From medium-resolution (R~1200-2000) spectroscopy of 857 candidates, we estimate the stellar atmospheric parameters (T_eff_, logg, and [Fe/H]), as well as carbon and {alpha}-element abundances. We find that 69% of the observed stars have [Fe/H]<=-1.0, 39% have [Fe/H]<=-2.0, and 2% have [Fe/H]<=-3.0. There are also 133 carbon-enhanced metal-poor (CEMP) stars in this sample, with 97 CEMP Group I and 36 CEMP Group II stars identified in the A(C) versus [Fe/H] diagram. A subset of the confirmed low-metallicity stars were followed-up with high-resolution spectroscopy, as part of the R-process Alliance, with the goal of identifying new highly and moderately r-process-enhanced stars. Comparison between the stellar atmospheric parameters estimated in this work and from high-resolution spectroscopy exhibit good agreement, confirming our expectation that medium-resolution observing campaigns are an effective way of selecting interesting stars for further, more targeted, efforts.
14219. Spectroscopy of luminous compact blue galaxies
ID:
ivo://CDS.VizieR/J/ApJ/817/87
Title:
Spectroscopy of luminous compact blue galaxies
Short Name:
J/ApJ/817/87
Date:
21 Oct 2021
Publisher:
CDS
Description:
Luminous Compact Blue Galaxies (LCBGs) are an extreme star-bursting population of galaxies that were far more common at earlier epochs than today. Based on spectroscopic and photometric measurements of LCBGs in massive (M>10^15^M_{sun}_), intermediate redshift (0.5<z<0.9) galaxy clusters, we present their rest-frame properties including star formation rate, dynamical mass, size, luminosity, and metallicity. The appearance of these small, compact galaxies in clusters at intermediate redshift helps explain the observed redshift evolution in the size-luminosity relationship among cluster galaxies. In addition, we find the rest-frame properties of LCBGs appearing in galaxy clusters are indistinguishable from field LCBGs at the same redshift. Up to 35% of the LCBGs show significant discrepancies between optical and infrared indicators of star formation, suggesting that star formation occurs in obscured regions. Nonetheless, the star formation for LCBGs shows a decrease toward the center of the galaxy clusters. Based on their position and velocity, we estimate that up to 10% of cluster LCBGs are likely to merge with another cluster galaxy. Finally, the observed properties and distributions of the LCBGs in these clusters lead us to conclude that we are witnessing the quenching of the progenitors of dwarf elliptical galaxies that dominate the number density of present-epoch galaxy clusters.
14220. Spectroscopy of M dwarfs in Praesepe
ID:
ivo://CDS.VizieR/J/AJ/132/1517
Title:
Spectroscopy of M dwarfs in Praesepe
Short Name:
J/AJ/132/1517
Date:
21 Oct 2021
Publisher:
CDS
Description:
Spectroscopy of 222 late-type dwarfs in the Praesepe open cluster is used to measure the strengths of molecular and atomic features and to examine their sensitivity to chromospheric activity as measured by the strength of H{alpha} emission.

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