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361. Combined NVSS-FIRST Galaxies (CoNFIG) sample
ID:
ivo://CDS.VizieR/J/MNRAS/390/819
Title:
Combined NVSS-FIRST Galaxies (CoNFIG) sample
Short Name:
J/MNRAS/390/819
Date:
21 Oct 2021
Publisher:
CDS
Description:
The CoNFIG (Combined NVSS-FIRST Galaxies) sample is a new sample of 274 bright radio sources at 1.4GHz. It was defined by selecting all sources with S1.4GHz-1.3Jy from the NRAO Very Large Array (VLA) Sky Survey (NVSS) in the north field of the Faint Images of the Radio Sky at Twenty centimetres (FIRST) survey. New radio observations obtained with the VLA for 31 of the sources are presented. The sample has complete Fanaroff-Riley (FRI)/FRII morphology identification; optical identifications and redshifts are available for 80 and 89 per cent of the sample, respectively, yielding a mean redshift of ~0.71. One of the goals of this survey is to get better definitions of luminosity distributions and source counts of FRI/FRII sources separately, in order to determine the evolution of the luminosity function for each type of source. We present a preliminary analysis, showing that these data are an important step towards examining various evolutionary schemes for these objects and to confirm or correct the dual population unified scheme for radio active galactic nuclei (AGN). Improving our understanding of radio galaxy evolution will give better insight into the role of AGN feedback in galaxy formation.
362. Combined NVSS-FIRST galaxies (CoNFIG) sample II
ID:
ivo://CDS.VizieR/J/MNRAS/404/1719
Title:
Combined NVSS-FIRST galaxies (CoNFIG) sample II
Short Name:
J/MNRAS/404/1719
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper focuses on a comparison of the space densities of Fanaroff-Riley type I (FR I) and FR II sources at different epochs, with a particular focus on FR I sources. First, we present the concluding steps in constructing the Combined NVSS-FIRST Galaxies (CoNFIG) catalogue, including new Very Large Array observations, optical identifications and redshift estimates. The final catalogue consists of 859 sources over four samples (CoNFIG-1, -2, -3 and -4 with flux density limits of S1.4GHz=1.3, 0.8, 0.2 and 0.05Jy, respectively). It is 95.7 per cent complete in radio morphology classification and 74.3 per cent of the sources have redshift data. Combining CoNFIG with complementary samples, the distribution and evolution of FR I and FR II sources are investigated. We find that FR I sources undergo mild evolution and that, at the same radio luminosity, FR I and FR II sources show similar space density enhancements in various redshift ranges, possibly implying a common evolution.
363. COMBS III
ID:
ivo://CDS.VizieR/J/MNRAS/509/122
Title:
COMBS III
Short Name:
J/MNRAS/509/122
Date:
08 Feb 2022 11:31:21
Publisher:
CDS
Description:
The characteristics of the stellar populations in the Galactic bulge inform and constrain the Milky Way's formation and evolution. The metal-poor population is particularly important in light of cosmological simulations, which predict that some of the oldest stars in the Galaxy now reside in its centre. The metal-poor bulge appears to consist of multiple stellar populations that require dynamical analyses to disentangle. In this work, we undertake a detailed chemodynamical study of the metal-poor stars in the inner Galaxy. Using R ~ 20 000 VLT/GIRAFFE spectra of 319 metal-poor (-2.55dex<=[Fe/H]<=0.83dex, with mean [Fe/H]=-0.84dex) stars, we perform stellar parameter analysis and report 12 elemental abundances (C, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Zn, Ba, and Ce) with precisions of ~0.10 dex. Based on kinematic and spatial properties, we categorize the stars into four groups, associated with the following Galactic structures: the inner bulge, the outer bulge, the halo, and the disc. We find evidence that the inner and outer bulge population is more chemically complex (i.e. higher chemical dimensionality and less correlated abundances) than the halo population. This result suggests that the older bulge population was enriched by a larger diversity of nucleosynthetic events. We also find one inner bulge star with a [Ca/Mg] ratio consistent with theoretical pair-instability supernova yields and two stars that have chemistry consistent with globular cluster stars.
364. COMBS survey. Galactic Bulge metal-poor stars
ID:
ivo://CDS.VizieR/J/MNRAS/488/2283
Title:
COMBS survey. Galactic Bulge metal-poor stars
Short Name:
J/MNRAS/488/2283
Date:
21 Oct 2021
Publisher:
CDS
Description:
Chemistry and kinematic studies can determine the origins of stellar population across the Milky Way. The metallicity distribution function of the bulge indicates that it comprises multiple populations, the more metal-poor end of which is particularly poorly understood. It is currently unknown if metal-poor bulge stars ([Fe/H]<-1dex) are part of the stellar halo in the inner most region, or a distinct bulge population or a combination of these. Cosmological simulations also indicate that the metal-poor bulge stars may be the oldest stars in the Galaxy. In this study, we successfully target metal-poor bulge stars selected using SkyMapper photometry. We determine the stellar parameters of 26 stars and their elemental abundances for 22 elements using R~47000 VLT/UVES spectra and contrast their elemental properties with that of other Galactic stellar populations. We find that the elemental abundances we derive for our metal-poor bulge stars have lower overall scatter than typically found in the halo. This indicates that these stars may be a distinct population confined to the bulge. If these stars are, alternatively, part of the inner-most distribution of the halo, this indicates that the halo is more chemically homogeneous at small Galactic radii than at large radii. We also find two stars whose chemistry is consistent with second-generation globular cluster stars. This paper is the first part of the Chemical Origins of Metal-poor Bulge Stars (COMBS) survey that will chemo-dynamically characterize the metal-poor bulge population.
365. Compact clouds in a sensitive GBT HI survey
ID:
ivo://CDS.VizieR/J/ApJ/855/33
Title:
Compact clouds in a sensitive GBT HI survey
Short Name:
J/ApJ/855/33
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a new sensitive survey of neutral hydrogen above and below the Galactic Center with the Green Bank Telescope. The observations extend up to Galactic latitude |b|<10{deg} with an effective angular resolution of 9.5' and an average rms brightness temperature noise of 40mK in a 1km/s channel. The survey reveals the existence of a population of anomalous high-velocity clouds extending up to heights of about 1.5kpc from the Galactic plane and showing no signature of Galactic rotation. These clouds have local standard of rest velocities |V_LSR_|<~360km/s, and assuming a Galactic Center origin, they have sizes of a few tens of parsec and neutral hydrogen masses spanning 10-10^5^M_{sun}_. Accounting for selection effects, the cloud population is symmetric in longitude, latitude, and VLSR. We model the cloud kinematics in terms of an outflow expanding from the Galactic Center and find the population consistent with being material moving with radial velocity V_w_~330km/s distributed throughout a bicone with opening angle {alpha}>140{deg}. This simple model implies an outflow luminosity L_w_>3x10^40^erg/s over the past 10Myr, consistent with star formation feedback in the inner region of the Milky Way, with a cold gas mass-loss rate <~0.1M_{sun}_/yr. These clouds may represent the cold gas component accelerated in the nuclear wind driven by our Galaxy, although some of the derived properties challenge current theoretical models of the entrainment process.
366. Compact Groups in SDSSDR12
ID:
ivo://CDS.VizieR/J/A+A/618/A157
Title:
Compact Groups in SDSSDR12
Short Name:
J/A+A/618/A157
Date:
21 Oct 2021
Publisher:
CDS
Description:
A catalogue of compact groups identified on the SDSS DR12 is provided. Compact Groups were identified in redshift space with a modified Hickson-like algorithm. The catalogue comprises 462 compact groups of which 406 clearly fulfil all the compact group requirements: compactness, isolation and velocity concordance of all of their members. The remaining 56 groups need further redshift information of potentially contaminating sources.
367. Compact groups of galaxies in LCRS
ID:
ivo://CDS.VizieR/J/AN/321/101
Title:
Compact groups of galaxies in LCRS
Short Name:
J/AN/321/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have recently extracted a catalog of compact groups of galaxies (CGs) from the Las Campanas Redshift Survey. This catalog of Las Campanas Compact Groups (LCCGs) contains 76 CGs with a median redshift of z_med_~0.08. The physical properties of these CGs are similar to those form Hickson (1982, Cat. <VII/213>) and the Barton et al. (1996AJ....112..871B) catalogs. Here, we present an atlas of our catalog and briefly describe its general properties.
368. Compact groups of galaxies in SDSS DR7
ID:
ivo://CDS.VizieR/J/MNRAS/418/1409
Title:
Compact groups of galaxies in SDSS DR7
Short Name:
J/MNRAS/418/1409
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the properties of photometrically selected compact groups (CGs) in the Sloan Digital Sky Survey. In this paper, the fourth in a series, we focus on understanding the characteristics of our observed CG sample with particular attention paid to quantifying and removing contamination from projected foreground or background galaxies. Based on a simple comparison of pairwise redshift likelihoods, we find that approximately half of CGs in the parent sample contain one or more projected (interloping) members; our final clean sample contains 4566 galaxies in 1086 CGs.
369. Compact groups of galaxies in SDSS DR6
ID:
ivo://CDS.VizieR/J/MNRAS/395/255
Title:
Compact groups of galaxies in SDSS DR6
Short Name:
J/MNRAS/395/255
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the largest publicly available catalogue of compact groups (CGs) of galaxies identified using the original selection criteria of Hickson, selected from the Sixth Data Release of the Sloan Digital Sky Survey (SDSS DR6). We identify 2297 CGs down to a limiting magnitude of r=18 (~0.24groups/deg^2^), and 74791 CGs down to a limiting magnitude of r=21 (~6.7groups/deg^2^). This represents 0.9 per cent of all galaxies in the SDSS DR6 at these magnitude levels.
370. Compact groups of galaxies in SDSS & LAMOST. I.
ID:
ivo://CDS.VizieR/J/ApJS/246/12
Title:
Compact groups of galaxies in SDSS & LAMOST. I.
Short Name:
J/ApJS/246/12
Date:
21 Oct 2021
Publisher:
CDS
Description:
A compact group (CG) is a kind of special galaxy system where the galaxy members are separated at distances of the order of galaxy size. The strong interaction between the galaxy members makes CGs ideal labs for studying the environmental effects on galaxy evolution. The traditional photometric selection algorithm biases against the CG candidates at low redshifts, while the spectroscopic identification technique is affected by the spectroscopic incompleteness of sample galaxies and typically biases against the high redshift candidates. In this study, we combine these two methods and select CGs in the main galaxy sample of the Sloan Digital Sky Survey, where we also have taken the advantages of the complementary redshift measurements from the LAMOST spectral and GAMA surveys. We have obtained the largest and most complete CG samples to date. Our samples include 6144 CGs and 8022 CG candidates, which are unique in the studies of the nature of the CGs and the evolution of the galaxies inside.