- ID:
- ivo://CDS.VizieR/J/A+A/578/A53
- Title:
- Spectroscopy of Herschel Dwarf Galaxy Survey
- Short Name:
- J/A+A/578/A53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Herschel PACS spectroscopic observations of the [CII] 157um, [OI] 63 and 145um, [OIII] 88um, [NII] 122 and 205um, and [NIII] 57um fine-structure cooling lines in a sample of 48 low-metallicity star-forming galaxies of the guaranteed time key program Dwarf Galaxy Survey. We correlate PACS line ratios and line-to-LTIR ratios with LTIR, LTIR/LB, metallicity, and FIR color, and interpret the observed trends in terms of ISM conditions and phase filling factors with Cloudy radiative transfer models. We find that the ISM of low-metallicity dwarf galaxies has a more porous structure than that of metal-rich galaxies. The radiation fields are harder and the the ionized gas/PDR filling factor is larger in the dwarfs.
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- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/474/941
- Title:
- Spectroscopy of H_2_ towards HH91A
- Short Name:
- J/A+A/474/941
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical and near-infrared spectroscopy of molecular hydrogen in interstellar shocks provide a very powerful probe of the physical conditions that prevail in interstellar shocks. Integral-field spectroscopy of H_2_ in the optical wavelength region and complementary long-slit near-infrared spectroscopy towards HH91A are used to characterize the ro-vibrational population distribution among H_2_ levels with excitation energies up to 30000cm^-1^.
- ID:
- ivo://CDS.VizieR/J/A+A/484/783
- Title:
- Spectroscopy of 7 INTEGRAL X-ray sources
- Short Name:
- J/A+A/484/783
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The INTEGRAL hard X-ray observatory has revealed an emerging population of highly obscured X-ray binary systems through multi-wavelength observations. Previous studies have shown that many of these sources are high-mass X-ray binaries hosting neutron stars orbiting around luminous and evolved companion stars. To better understand this newly-discovered population, we have selected a sample of sources for which an accurate localisation is available to identify the stellar counterpart and reveal the nature of the companion star and of the binary system.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+AS/129/541
- Title:
- Spectroscopy of IRC +10420
- Short Name:
- J/A+AS/129/541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A high resolution optical spectrum of the post-red supergiant candidate IRC +10420 is presented. The Utrecht Echelle Spectrograph observations, with a total integration time of more than 9 hours provide a spectral coverage from 3850 A to 1micron, and a spectral resolution of 9km/s. The spectrum is shown, and an identification list of lines in the spectrum is provided. From a preliminary analysis of the spectrum we find that the spectral type of IRC+10420 has changed from F8I+ in 1973 to mid- to early A type now, confirming the results of Oudmaijer et al. (1996MNRAS.280.1062O), who claimed a change in temperature based on photometric changes. It is shown that most of the emission lines in the spectrum of IRC +10420 are blue-shifted with respect to the systemic velocity traced by circumstellar rotational CO emission, while the (few) absorption lines - with the exception of some high excitation lines - are red-shifted by 25km/s, which may suggest infall of material onto the star. Finally, it is found that the interstellar extinction towards IRC +10420, as traced by the Diffuse Interstellar Bands is very large, with an inferred E(B-V) of 1.4+/-0.5 compared to a total E(B-V) of 2.4. This table provides the line identifications for the measured spectral lines from atomic species. Listed in the table are respectively the laboratory wavelength (in air) taken from Moore (1945, in A multiplet table of astrophysical interest, Contribution from the Princeton University Observatory No. 20.), the line identification (ion and multiplet), the energies of the lower levels of the transitions in eV, and the log(gf). The latter two values are taken from Wiese et al. (1966, Nat. Stand. Ref. Data Ser. 20 and 1969, Nat. Stand. Ref. Data Ser. 22), Martin et al. (1988, Cat. <VI/72>) and Fuhr et al. (1988, Cat. <VI/72>). The spectral lines that are marked `UN' were not identified, the wavelength given for these lines is the observed wavelength. Then next entries in the table are the velocity shift of the centres of spectral lines (in LSR), the equivalent width in milli-Angstrom, and the full-width-at-half maximum of the fit in Angstrom. The velocity shifts have been measured by fitting Gaussian profiles through the lines, the equivalent widths have been measured by integrating the line over the continuum. In the case of overlapping lines, the lines were de-composed by fitting multiple Gaussian components to the profiles. In these cases (marked with `deb.' in the table) the equivalent widths are the areas under the Gaussian fits. Equivalent widths for lines that could not be deblended, are given between brackets. These values represent the total equivalent width of the lines concerned.
- ID:
- ivo://CDS.VizieR/J/A+AS/131/119
- Title:
- Spectroscopy of irregular variables
- Short Name:
- J/A+AS/131/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of optical spectroscopy of 169 southern and equatorial objects previously known as irregular variables are presented. The targets were selected via photoelectric UBV photometry among objects classified as L, L:, I, I:, IS and IS: in the General Catalogue of Variable Stars and New Catalogue of Suspected Variable Stars. Among these objects we have identified 8 cataclysmic variables, 8 symbiotic stars and stars that belong to a variety of other classes.
- 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.
- 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.
- 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.
