- 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.
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Search Results
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/722/395
- Title:
- Compact H I clouds from the GALFA-H I survey
- Short Name:
- J/ApJ/722/395
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic Arecibo L-band Feed Array H I (GALFA-H I) survey is mapping the entire Arecibo sky at 21 cm, over a velocity range of -700 to +700 km/s (LSR), at a velocity resolution of 0.18 km/s, and a spatial resolution of 3.5 arcmin. The unprecedented resolution and sensitivity of the GALFA-H I survey have resulted in the detection of numerous isolated, very compact H I clouds at low Galactic velocities, which are distinctly separated from the H I disk emission. In the limited area of ~4600 deg^2^ surveyed so far, we have detected 96 such compact clouds. The detected clouds are cold with a median T_k,max_ (the kinetic temperature in the case in which there is no non-thermal broadening) of 300 K. Moreover, these clouds are quite compact and faint, with median values of 5 arcmin in angular size, 0.75 K in peak brightness temperature, and 5x10^18^/cm2 in H I column density. Most of the clouds deviate from Galactic rotation at the 20-30 km/s level, and a significant fraction show evidence for a multiphase medium and velocity gradients. No counterparts for these clouds were found in other wave bands. From the modeling of spatial and velocity distributions of the whole compact cloud population, we find that the bulk of the compact clouds are related to the Galactic disk, and their distances are likely to be in the range of 0.1 to a few kpc. We discuss various possible scenarios for the formation and maintenance of this cloud population and its significance for Galactic interstellar medium studies.
- ID:
- ivo://CDS.VizieR/J/ApJ/623/181
- Title:
- Compact high-velocity cloud photometry catalog
- Short Name:
- J/ApJ/623/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a photometric search for giant stars associated with the cores of four high-velocity clouds (HVCs) - two of which are compact HVCs - using the Las Campanas du Pont 2.5m and Cerro Tololo Blanco 4m telescopes in combination with a system of filters (Washington M, T_2_ + DDO51) useful for identifying low surface gravity, evolved stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/1527
- Title:
- Compact HII regions IR photometry
- Short Name:
- J/MNRAS/391/1527
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 3.6, 4.5, 5.8 and 8.0um photometry and mapping for 58 compact HII regions identified using the Spitzer Galactic Legacy Infrared Midplane Survey Extraordinaire (GLIMPSE). These are used to investigate trends in the colours, magnitudes and structures of the sources, together with spatial variations in flux ratio. It is concluded that most of the sources are remarkably similar, and have comparable variations in flux ratio as a function of position within the shells, together with very narrowly defined ranges of colour index.
- ID:
- ivo://CDS.VizieR/J/MNRAS/268/602
- Title:
- Compact radio cores in radio galaxies.
- Short Name:
- J/MNRAS/268/602
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains compact core fluxes for a list of 175 southern radio galaxies, measured with the Parkes-Tidbinbilla Interferometer (PTI, Norris et al. 1988ApJS...67...85N) on a single 275 km baseline at 2.3 GHz and 8.4 GHz. The sample consists of large angular size ( > 0.5 arcmin) steep spectrum sources from Jones & McAdam (1992ApJS...80..137J) observed to determine the fraction of flux contained in compact (VLBI-scale) cores. Of the 172 sources observed at 2.3 GHz (100 milliarcsec fringe spacing), 63 had cores detected and upper limits were determined for the remaining 109. Of the 88 sources observed at 8.4 GHz (30 milliarcsec fringe spacing), 38 had cores detected and 50 have upper limits. A comparison of the detections and upper limits at the two frequencies shows that the cores have flat or inverted spectra. The core fluxes quoted here may vary by around 20 % if there is structure on the scale of the fringe spacing and the cores are probably intrinsically variable.
- ID:
- ivo://CDS.VizieR/J/ApJS/145/83
- Title:
- Compact radio sources at -30<Dec<0
- Short Name:
- J/ApJS/145/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 321 compact radio sources in the declination range 0{deg}>{delta}>-30{deg}. The positions of these sources have been measured with a two-dimensional rms accuracy of 35milliarcseconds using the NRAO Very Large Array. Each source has a peak flux density >50mJy at 8.4GHz. We intend for this catalog to be used mainly for selection of phase calibration sources for radio interferometers, although compact radio sources have other scientific uses.
- ID:
- ivo://CDS.VizieR/J/A+AS/126/325
- Title:
- Compact Radio Sources in & behind LMC catalogue
- Short Name:
- J/A+AS/126/325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a continuum snapshot survey of a 3x4{deg}^2^ region of the Large Magellanic Cloud including the area of the giant molecular cloud and the 30 Doradus nebula. The observations have been carried out with the Australia Telescope Compact Array (ATCA) at 1.4 and 2.4GHz. Most fields are complete to about 6mJy peak flux density at 1.4GHz and to about 3mJy at 2.4GHz. The positions, peak and integral flux densities of 113 compact (<54") sources detected at 1.4GHz and of 70 sources (<34") detected at 2.4GHz are presented. Positions are accurate to about 3" and peak flux densities are accurate to about 10% or better, depending on the source position relative to the pointing centers. 32 of the sources detected at 1.4GHz are coincident with H{alpha} objects in the catalogue of Davies, Elliot and Meaburn (1976MmRAS..81...89D); these are possibly intrinsic to the LMC. However, we suppose that most are background objects, since the number vs. flux agrees with predictions of extragalactic source counts from other surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/610/A27
- Title:
- Compact radio sources in NGC 6334D to F
- Short Name:
- J/A+A/610/A27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The presence and properties of compact radio sources embedded in massive star forming regions can reveal important physical properties about these regions and the processes occurring within them. The NGC 6334 complex, a massive star forming region, has been studied extensively. Nevertheless, none of these studies has focused in its content in compact radio sources. Aims. Our goal here is to report on a systematic census of the compact radio sources toward NGC 6334, and their characteristics. This will be used to attempt to define their very nature. We used the VLA C band (4-8GHz) archive data with 0.36" (500AU) of spatial resolution and noise level of 50Jy/bm to carry out a systematic search for compact radio sources within NGC 6334. We also searched for infrared counterparts to provide some constraints on the nature of the detected radio sources. A total of 83 compact sources and three slightly resolved sources were detected. Most of them are here reported for the first time. We found that 29 of these 86 sources have infrared counterparts and three are highly variable. Region D contains 18 of these sources. The compact source toward the center, in projection, of region E is also detected. From statistical analyses, we suggest that the 83 reported compact sources are real and most of them are related to NGC 6334 itself. A stellar nature for 27 of them is confirmed by their IR emission. Compared with Orion, region D suffers a deficit of compact radio sources. The infrared nebulosities around two of the slightly resolved sources are suggested to be warm dust, and we argue that the associated radio sources trace free-free emission from ionized material. We confirm the thermal radio emission of the compact source in region E. However, its detection at infrared wavelengths implies that it is located in the foreground of the molecular cloud. Finally, three strongly variable sources are suggested to be magnetically active young stars.