- ID:
- ivo://CDS.VizieR/J/AJ/131/2426
- Title:
- Optical and radio study of Abell 2111
- Short Name:
- J/AJ/131/2426
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an in-depth analysis of the Butcher-Oemler cluster A2111, including new optical spectroscopy plus a deep Very Large Array (VLA) radio continuum observation. These are combined with optical imaging from the Sloan Digital Sky Survey (SDSS) to assess the activity and properties of member galaxies. Prior X-ray studies have suggested A2111 to be a head-on cluster merger, a dynamical state that might be connected to the high level of activity inferred from its blue fraction. We are able to directly assess this claim, using our spectroscopic data to identify 95 cluster members among 196 total galaxy spectra. We are able to detect 175 optical sources from the SDSS in our VLA radio data, of which 35 have redshift information.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/329/700
- Title:
- Optical IDs of JVAS using APM
- Short Name:
- J/MNRAS/329/700
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Files list1, list2, and list3 contain the lists of flat spectrum radio sources with their optical identifications from the APM (Automated Plate Measurement Facility at Cambridge) catalogue. List1 corresponds to the sources which are part of both the complete JVAS++ (a new complete sample constructed with selection criteria similar to those of JVAS -- Jodrell Bank VLA Astrometric Survey: S_5GHz_>200mJy, {alpha}_1.4-5GHz_>-0.5), and with the use of the more accurate GB6 and NVSS surveys) and original JVAS sample, List2 corresponds to sources which are only part of JVAS++, and List3 to sources which are only part of JVAS. The combination of List1 and List2 is a complete sample with S_6cm_>200mJy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/238/1171
- Title:
- Optical/IR observ. of Radio Galaxies and QSOs
- Short Name:
- J/MNRAS/238/1171
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog reports on an extensive optical and infrared study of the 178 radio sources in the Parkes Selected Regions (S > 100 mJy at 2.7 GHz). CCD observations have resulted in the essential completion (95 percent) of optical identifications and have provided B and R photometry. In addition, K photometry has been completed for four of the six selected regions.
- ID:
- ivo://CDS.VizieR/J/A+A/463/97
- Title:
- Optical observations of GPS radio sources
- Short Name:
- J/A+A/463/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify optical counterparts, address uncertain identifications and measure previously unknown redshifts of the host galaxies of candidate Gigahertz Peaked Spectrum (GPS) radio sources, and study their stellar populations. Long slit spectroscopy and deep optical imaging in the B, V and R bands, were obtained with the Very Large Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/1119
- Title:
- Optical properties of radio galaxies at z<0.3
- Short Name:
- J/ApJ/723/1119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extended extragalactic radio sources have traditionally been classified into Fanaroff & Riley (FR) I and II types, based on the ratio r_s_ of the separation S between the brightest regions on either sides of the host galaxy and the total size T of the radio source (r_s_~S/T). In this paper, we examine the distribution of various physical properties as a function of r_s_ of 1040 luminous (L>~L*) extended radio galaxies (RGs) at z<0.3 selected with well-defined criteria from the SDSS (Strauss et al. 2002AJ....124.1810S), NVSS (Condon et al. 1998, Cat. VIII/65), and FIRST (Becker et al. 1995+, Cat. VIII/71) surveys. About 2/3 of the RGs are lobe dominated (LD) and 1/3 have prominent jets. If we follow the original definition of the FR types, i.e., a division based solely on r_s_, FRI and FRII RGs overlap in their host galaxy properties.
- ID:
- ivo://CDS.VizieR/J/ApJ/616/71
- Title:
- Optical properties of SCUBA galaxies
- Short Name:
- J/ApJ/616/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present optical and near-infrared photometry for a sample of 96 dusty, far-infrared luminous galaxies. We have precise spectroscopic redshifts for all these galaxies, yielding a median redshift of <z>=2.2. The majority, 78, are submillimeter-detected galaxies lying at z=0.2-3.6, while the remaining 18 are optically faint {mu}Jy radio galaxies at z=0.9-3.4 that are proposed to be similarly luminous, dusty galaxies whose dust emission is too hot to be detected in the submillimeter waveband.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/220
- Title:
- Optical redshifts of OH- and HI-emitting galaxies
- Short Name:
- J/MNRAS/459/220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- OH megamasers (OHMs) are rare, luminous molecular masers that are typically observed in (ultra) luminous infrared galaxies and serve as markers of major galaxy mergers. In blind emission line surveys such as the Arecibo Legacy Fast Arecibo L-Band Feed Array (ALFALFA) survey for neutral hydrogen (HI), OHMs at z~0.2 can mimic z~0.05 HI lines. We present the results of optical spectroscopy of ambiguous HI detections in the ALFALFA 40 per cent data release detected by the Wide Field Infrared Survey Explorer (WISE) but with uncertain optical counterparts. The optical redshifts, obtained from observations at the Apache Point Observatory, revealed five new OHMs and identified 129 HI optical counterparts. 60 candidates remain ambiguous. The new OHMs are the first detected in a blind spectral line survey. The number of OHMs in ALFALFA is consistent with predictions from the OH luminosity function. Additionally, the mid-infrared magnitudes and colours of the OHM host galaxies found in a blind survey do not seem to differ from those found in previous targeted surveys. This validates the methods used in previous IR-selected OHM surveys and indicates there is no previously unknown OHM-producing population at z~0.2. We also provide a method for future surveys to separate OH megamasers from 99 per cent of HI line emitters without optical spectroscopy by using WISE infrared colours and magnitudes. Since the fraction of OHMs found in flux-limited HI surveys is expected to increase with the survey's redshift, this selection method can be applied to future flux-limited high-redshift hydrogen surveys.
- ID:
- ivo://CDS.VizieR/J/other/RMxAA/48.9
- Title:
- Optical spectroscopic atlas of MOJAVE AGNs
- Short Name:
- J/other/RMxAA/48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an optical spectroscopic atlas for 123 core-dominated radio-loud active galactic nuclei with relativistic jets, drawn from the MOJAVE/2cm (Monitoring of Jets in AGN with VLBA Experiments) sample at 15GHz. It is the first time that spectroscopic and photometric parameters for a large sample of such type of AGN are presented.
- ID:
- ivo://CDS.VizieR/J/AJ/109/14
- Title:
- Optical spectroscopy of Abell clusters. I.
- Short Name:
- J/AJ/109/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a program of optical spectroscopy of radio galaxies in rich clusters. Redshifts are reported for 268 radio galaxies or close companions in Abell clusters and 36 objects which turned out to be foreground or background objects. Absolute line strengths are also reported for the 3727{AA} [OII] line and the [NII]/H{alpha} complex. We find no evidence that the radio activity in our sample of mostly FR I radio galaxies is associated with emission-line luminosities above those found in "normal" galaxies of the same absolute magnitude and optical type. We also find that the radial velocity differences between radio galaxies and the cluster mean seem mainly to be a function of galaxy absolute magnitude rather than radio properties.
- ID:
- ivo://CDS.VizieR/J/AJ/155/188
- Title:
- Origin of nuclear activity in low-power radio galaxies
- Short Name:
- J/AJ/155/188
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using large samples containing nearly 2300 active galaxies of low radio luminosity (1.4 GHz luminosity between 2x10^23^ and 3x10^25^ W/Hz, essentially low-excitation radio galaxies) at z~<0.3, we present a self-contained analysis of the dependence of the nuclear radio activity on both intrinsic and extrinsic properties of galaxies, with the goal of identifying the best predictors of the nuclear radio activity. While confirming the established result that stellar mass must play a key role on the triggering of radio activities, we point out that for the central, most massive galaxies, the radio activity also shows a strong dependence on halo mass, which is not likely due to enhanced interaction rates in denser regions in massive, cluster-scale halos. We thus further investigate the effects of various properties of the intracluster medium (ICM) in massive clusters on the radio activities, employing two standard statistical tools, principle component analysis and logistic regression. It is found that ICM entropy, local cooling time, and pressure are the most effective in predicting the radio activity, pointing to the accretion of gas cooling out of a hot atmosphere to be the likely origin in triggering such activities in galaxies residing in massive dark matter halos. Our analysis framework enables us to logically discern the mechanisms responsible for the radio activity separately for central and satellite galaxies.
