- ID:
- ivo://CDS.VizieR/J/MNRAS/391/869
- Title:
- A mapping survey of massive CO cores
- Short Name:
- J/MNRAS/391/869
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We mapped 21 star-forming regions with the ^12^CO, ^13^CO and C^18^O (1-0) lines using the 13.7-m telescope of Purple Mount Observatory. This mapping survey resolved 53 ^13^CO cores, of which 22 are sourceless. We obtained the physical parameters of these cores. The relation between ^13^CO linewidth and core size and that between column density and core size were analysed. The cores 00211+6549-1 and 22566+5830 were found to have outflows. Systematic VLSR shifts were detected in nine regions: 00211+6549, 00232+6437, 05168+3634, 19199+1358, 20160+3911, 22566+5830, 23042+6000, S146 and S270. Signatures of infall and cloud collision were found in regions 18507+0121 and 19199+1358, respectively. We studied the mass function of these ^13^CO cores. The core masses range from 3.40 to 4.64x10^4^M_{sun}_, and the core mass function is a power-law distribution of index -0.82+/-0.04.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/708/1290
- Title:
- A 2MASS view of the Sgr dSph. VI.
- Short Name:
- J/ApJ/708/1290
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present high-resolution spectroscopic measurements of the abundances of the {alpha} element titanium (Ti) and s-process elements yttrium (Y) and lanthanum (La) for 59 candidate M giant members of the Sagittarius (Sgr) dwarf spheroidal (dSph) + tidal tail system pre-selected on the basis of position and radial velocity (RV). As expected, the majority of these stars show peculiar abundance patterns compared to those of nominal Milky Way (MW) stars, but as a group, the stars form a coherent picture of chemical enrichment of the Sgr dSph from [Fe/H]=-1.4 to solar abundance. Finally, we analyze the chemical abundances of a moving group of M giants among the Sgr leading arm stars at the North Galactic Cap, but having RVs unlike the infalling Sgr leading arm debris there. Through use of "chemical fingerprinting," we conclude that these mostly receding northern hemisphere M giants also are Sgr stars, likely trailing arm debris overlapping the Sgr leading arm in the north.
- ID:
- ivo://CDS.VizieR/J/A+A/647/A162
- Title:
- AMBRE catalogue of sulfur abundances
- Short Name:
- J/A+A/647/A162
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sulfur is a volatile chemical element that plays an important role in tracing the chemical evolution of the Milky Way and external galaxies. However, its nucleosynthesis origin and abundance variations in the Galaxy are still unclear because the number of available stellar sulfur abundance measurements is currently rather small. The goal of the present article is to accurately and precisely study the sulfur content of large number of stars located in the solar neighbourhood. We use the parametrisation of thousands of high-resolution stellar spectra provided by the AMBRE Project, and combine it with the automated abundance determination GAUGUIN to derive local thermodynamic equilibrium (LTE) sulfur abundances for 1855 slow-rotating FGK-type stars. This is the largest and most precise catalogue of sulfur abundances published to date. It covers a metallicity domain as high as ~2.5dex starting at [M/H]<~-2.0dex. We find that the sulfur-to-iron abundances ratio is compatible with a plateau-like distribution in the metal-poor regime, and then starts to decrease continuously at [M/H]~-1.0dex. This decrease continues towards negative values for supersolar metallicity stars as recently reported for magnesium and as predicted by Galactic chemical evolution models. Moreover, sulfur-rich stars having metallicities in the range [-1.0,-0.5] have very different kinematical and orbital properties with respect to more metal-rich and sulfur-poor ones. Two disc components, associated with the thin and thick discs, are thus seen independently in kinematics and sulfur abundances. The sulfur radial gradients in the Galactic discs have also been estimated. Finally, the enrichment in sulfur with respect to iron is nicely correlated with stellar ages: older metal-poor stars have higher [S/M] ratios than younger metal-rich ones. This work has confirmed that sulfur is an {alpha}-element that could be considered to explore the Galactic populations properties. For the first time, a chemo-dynamical study from the sulfur abundance point of view, as a stand-alone chemical element, is performed.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A48
- Title:
- AMBRE project. FEROS archived spectra
- Short Name:
- J/A+A/542/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The AMBRE Project is a collaboration between the European Southern Observatory (ESO) and the Observatoire de la Cote d'Azur (OCA) that has been established in order to carry out the determination of stellar atmospheric parameters for the archived spectra of four ESO spectrographs. The analysis of the FEROS archived spectra for their stellar parameters (effective temperatures, surface gravities, global metallicities, alpha element to iron ratios and radial velocities) has been completed in the first phase of the AMBRE Project. From the complete ESO:FEROS archive dataset that was received, a total of 21551 scientific spectra have been identified, covering the period 2005 to 2010. These spectra correspond to 6285 stars. The determination of the stellar parameters was carried out using the stellar parameterisation algorithm, MATISSE (MATrix Inversion for Spectral SynthEsis), which has been developed at OCA to be used in the analysis of large scale spectroscopic studies in galactic archaeology. An analysis pipeline has been constructed that integrates spectral normalisation, cleaning and radial velocity correction procedures in order that the FEROS spectra could be analysed automatically with MATISSE to obtain the stellar parameters. The synthetic grid against which the MATISSE analysis is carried out is currently constrained to parameters of FGKM stars only. Stellar atmospheric parameters, effective temperature, surface gravity, metallicity and alpha element abundances, were determined for 6508 (30.2%) of the FEROS archived spectra (~3087 stars). Radial velocities were determined for 11963 (56%) of the archived spectra. 2370 (11%) spectra could not be analysed within the pipeline due to very low signal-to-noise ratios or missing spectral orders. 12673 spectra (58.8%) were analysed in the pipeline but their parameters were discarded based on quality criteria and error analysis determined within the automated process. The majority of these rejected spectra were found to have broad spectral features, as probed both by the direct measurement of the features and cross-correlation function breadths, indicating that they may be hot and/or fast rotating stars, which are not considered within the adopted reference synthetic spectra grid. The current configuration of the synthetic spectra grid is devoted to slow-rotating FGKM stars. Hence non-standard spectra (binaries, chemically peculiar stars etc.) that could not be identified may pollute the analysis.
- ID:
- ivo://CDS.VizieR/J/MNRAS/410/2662
- Title:
- AMI 1.8cm observations in c2d small clouds
- Short Name:
- J/MNRAS/410/2662
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We perform deep 1.8-cm radio continuum imaging towards 13 protostellar regions selected from the Spitzer c2d small clouds and cores programme at high resolution (25-arcsec) in order to detect and quantify the cm-wave emission from deeply embedded young protostars. Within these regions we detect 15 compact radio sources which we identify as radio protostars including two probable new detections. The sample is in general of low bolometric luminosity and contains several of the newly detected VeLLO sources. We determine the 1.8cm radio luminosity to bolometric luminosity correlation, L_rad_-L_bol_, for the sample and discuss the nature of the radio emission in terms of the available sources of ionized gas. We also investigate the Lrad-LIR correlation and suggest that radio flux density may be used as a proxy for the internal luminosity of low-luminosity protostars.
- ID:
- ivo://CDS.VizieR/J/ApJS/126/85
- Title:
- A mid-infrared galaxy atlas (MIGA)
- Short Name:
- J/ApJS/126/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A mid-infrared atlas of part of the Galactic plane (75{deg}<l<148{deg}, b=+/-6{deg}) has been constructed using HIRES processed infrared data to provide a mid-infrared data set for the Canadian Galactic Plane Survey (CGPS). The addition of this data set to the CGPS will enable the study of the emission from the smallest components of interstellar dust at an angular resolution comparable to that of the radio, millimeter, and far-infrared data in the CGPS. The Mid-Infrared Galaxy Atlas (MIGA) is a mid-infrared (12 and 25um) counterpart to the far-infrared IRAS Galaxy Atlas (IGA), and consists of resolution enhanced (~0.5' resolution) HIRES images along with ancillary maps. This paper describes the processing and characteristics of the atlas, the cross-band simulation technique used to obtain high-resolution ratio maps, and future plans to extend both the IGA and MIGA.
- ID:
- ivo://CDS.VizieR/J/MNRAS/434/325
- Title:
- 452 AMIGA galaxies physical parameters
- Short Name:
- J/MNRAS/434/325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Disentangling processes governing the formation and evolution of galaxies is a fundamental challenge in extragalactic research. In this sense the current belief that galaxies grow by the action of minor mergers makes the study of the stellar mass-size relation in different environments an important tool for distinguishing effects of internal and external processes. The aim of this work is to study the effects of environment on the growth in size of galaxies. As part of AMIGA project (Analysis of the Interstellar Medium of Isolated GAlaxies), we examine the stellar mass-size relation for a sample of the most isolated galaxies in the local Universe interpreted as stellar systems where evolution has been mainly governed by internal processes. Effects of environment on the stellar mass-size relation are evaluated by comparing our results with samples of less isolated early- and late-type galaxies, as well as, for the first time, different spiral subtypes. Stellar masses in our sample were derived by fitting the SED of each galaxy with kcorrect. We used two different size estimators, the half-light radius obtained with SExtractor and the effective radius calculated by fitting a Sersic profile to the i-band image of each galaxy using GALFIT.We found good agreement between those size estimators when the Sersic index fell in the range 2.5<n<4.5 and 0.5<n<2.5 for (visually classified) early- and late-type galaxies respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/788/L39
- Title:
- AMIGA galaxies structural parameters
- Short Name:
- J/ApJ/788/L39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present structural parameters and (g-i) bulge/disk colors for a large sample (189) of isolated AMIGA galaxies. The structural parameters of bulges were derived from the two-dimensional bulge/disk/bar decomposition of Sloan Digital Sky Survey i-band images using GALFIT. Galaxies were separated between classical bulges (n_b_>2.5) and pseudobulges (n_b_<2.5), resulting in a dominant pseudobulge population (94%) with only 12 classical bulges. In the <{mu}_e_>-R_e_plane, pseudobulges are distributed below the elliptical relation (smaller R_e_ and fainter {mu}_e_), with the closest region to the Kormendy relation populated by those pseudobulges with larger values of B/T. We derived (g-i) bulge colors using aperture photometry and find that pseudobulges show median colors (g-i)_b_~1.06, while their associated disks are much bluer, (g-i)_d_~0.77. Moreover, 64% (113/177) of pseudobulges follow the red sequence of early-type galaxies. Bluer pseudobulges tend to be located in galaxies with the highest likelihood of tidal perturbation. The red bulge colors and low B/T values for AMIGA isolated galaxies are consistent with an early formation epoch and not much subsequent growth. Properties of bulges in isolated galaxies contrast with a picture where pseudobulges grow continuously via star formation. They also suggest that environment could be playing a role in rejuvenating the pseudobulges.
749. AMIGA III. IRAS data
- ID:
- ivo://CDS.VizieR/J/A+A/462/507
- Title:
- AMIGA III. IRAS data
- Short Name:
- J/A+A/462/507
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the mid- (MIR) and far- (FIR) infrared properties of a large (~1000) sample of the most isolated galaxies in the local Universe. This sample is intended as a "nurture-free" zero point against which more environmentally influenced samples can be compared. We reprocess IRAS MIR/FIR survey data using the ADDSCAN/SCANPI utility for 1030 out of 1050 galaxies from the Catalogue of Isolated Galaxies (CIG, Cat. <VII/82>) as part of the AMIGA survey. We focus on diagnostics (FIR luminosity LFIR , R=log(LFIR/LB) and IRAS colours) thought to be sensitive to effects of environment or interaction.
- ID:
- ivo://CDS.VizieR/J/A+A/449/937
- Title:
- AMIGA. II. Morphological refinement
- Short Name:
- J/A+A/449/937
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a refinement of the optical morphologies for galaxies in the Catalog of Isolated Galaxies (Karachentseva et al., 1973, Cat. <VII/82>) that forms the basis of the AMIGA (Analysis of the interstellar Medium of Isolated GAlaxies) project. Uniform reclassification using the digitized POSS II data benefited from the high resolution and dynamic range of that sky survey. Comparison with independent classifications made for an SDSS overlap sample of more than 200 galaxies confirms the reliability of the early vs. late-type discrimination and the accuracy of spiral subtypes within {Delta}T=1-2. CCD images taken at the Observatorio de Sierra Nevada (OSN) were also used to solve ambiguities in early versus late-type classifications. A considerable number of galaxies in the catalog (n=193) are flagged for the presence of nearby companions or signs of distortion likely due to interaction. This most isolated sample of galaxies in the local Universe is dominated by two populations: 1) 82% are spirals (Sa-Sd) with the bulk being luminous systems with small bulges (63% between types Sb-Sc) and 2) a significant population of early-type E-S0 galaxies (14%).
