- ID:
- ivo://CDS.VizieR/J/A+A/648/A102
- Title:
- FR-type radio sources at 3GHz VLA-COSMOS
- Short Name:
- J/A+A/648/A102
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Radio active galactic nuclei (AGN) are traditionally separated into two Fanaro-Riley (FR) type classes, edge-brightened FRII sources or edge-darkened FRI sources. With the discovery of a plethora of radio AGN of different radio shapes, this dichotomy is becoming too simplistic in linking the radio structure to the physical properties of radio AGN, their hosts, and their environment. We probe the physical properties and large-scale environment of radio AGN in the faintest FR population to date, and link them to their radio structure. We use the VLA-COSMOS Large Project at 3GHz (3GHz VLA-COSMOS), with a resolution and sensitivity of 0.75" and 2.3Jy/beam to explore the FR dichotomy down to Jy levels. We classified objects as FRIs, FRIIs, or hybrid FRI/FRII based on the surface-brightness distribution along their radio structure. Our control sample was the jet-less/compact radio AGN objects (COM AGN), which show excess radio emission at 3GHz VLA-COSMOS exceeding what is coming from star-formation alone; this sample excludes FRs. The largest angular projected sizes of FR objects were measured by a machine-learning algorithm and also by hand, following a parametric approach to the FR classification. Eddington ratios were calculated using scaling relations from the X-rays, and we included the jet power by using radio luminosity as a probe. Furthermore, we investigated their host properties (star-formation ratio, stellar mass, morphology), and we explore their incidence within X-ray galaxy groups in COSMOS, and in the density fields and cosmic-web probes in COSMOS. Our sample is composed of 59 FRIIs, 32 FRI/FRIIs, 39 FRIs, and 1818 COM AGN at 0.03<=z<=6. On average, FR objects have similar radio luminosities (L_3GHz_~10^23^W/Hz/sr), spanning a range of 10^21-26^W/Hz/sr, and they lie at a median redshift of z~1. The median linear projected size of FRIIs is 106.6^238.2^_36.9_kpc, larger than that of FRI/FRIIs and FRIs by a factor of 2-3. The COM AGN have sizes smaller than 30kpc, with a median value of 1.7^4.7^_1.5_kpc. The median Eddington ratio of FRIIs is 0.006^0.007^_0.005_, a factor of 2.5 less than in FRIs and a factor of 2 higher than in FRI/FRII. When the jet power is included, the median Eddington ratios of FRII and FRI/FRII increase by a factor of 12 and 15, respectively. FRs reside in their majority in massive quenched hosts (M*>10^10.5^M_{sun}_), with older episodes of star-formation linked to lower X-ray galaxy group temperatures, suggesting radio-mode AGN quenching. Regardless of their radio structure, FRs and COM AGN are found in all types and density environments (group or cluster, filaments, field). By relating the radio structure to radio luminosity, size, Eddington ratio, and large-scale environment, we find a broad distribution and overlap of FR and COM AGN populations. We discuss the need for a different classification scheme, that expands the classic FR classification by taking into consideration the physical properties of the objects rather than their projected radio structure which is frequency-, sensitivity- and resolution-dependent. This point is crucial in the advent of current and future all-sky radio surveys.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/other/Ap/52.40
- Title:
- FSS galaxies in southern hemisphere
- Short Name:
- J/other/Ap/52.40
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the properties of the 3838 galaxies that were monitored for SNe events, including newly determined morphologies and their DENIS and POSS-II/UKST I, 2MASS and DENIS J and K_s_ and 2MASS H magnitudes. We have compared 2MASS, DENIS and POSS-II/UKST IJK magnitudes in order to find possible systematic photometric shifts in the measurements. The DENIS and POSS-II/UKST I band magnitudes show large discrepancies (mean absolute difference of 0.4mag), mostly due to different spectral responses of the two instruments, with an important contribution (0.33mag rms) from the large uncertainties in the photometric calibration of the POSS-II and UKST photographic plates. In the other wavebands, the limiting near infrared magnitude, morphology, and inclination of the galaxies are the most influential factors which affect the determination of photometry of the galaxies. Nevertheless, no significant systematic differences have been found between of any pair of NIR magnitude measurements, except for a few percent of galaxies showing large discrepancies. This allows us to combine DENIS and 2MASS data for the J and K_s_ filters.
1123. FSVS Cluster Catalogue
- ID:
- ivo://CDS.VizieR/J/MNRAS/369/1334
- Title:
- FSVS Cluster Catalogue
- Short Name:
- J/MNRAS/369/1334
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a large sample of 598 galaxy clusters and rich groups discovered in the data of the Faint Sky Variability Survey (FSVS). The clusters have been identified using a fully automated, semiparametric technique based on a maximum likelihood approach applied to Voronoi tessellation, and enhanced by colour discrimination. The sample covers a wide range of richness, has a density of ~28 clusters/deg^2^, and spans a range of estimated redshifts of 0.05<z<0.9 with mean <z>=0.345. Assuming the presence of a cluster red sequence, the uncertainty of the estimated cluster redshifts is assessed to be {sigma}~0.03. Containing over 100 clusters with z>0.6, the catalogue contributes substantially to the current total of optically selected, intermediate-redshift clusters, and complements the existing, usually X-ray selected, samples. The FSVS fields are accessible for observation throughout the whole year, making them particularly suited for large follow-up programmes. The construction of this FSVS Cluster Catalogue completes a fundamental component of our continuing programmes to investigate the environments of quasars and the chemical evolution of galaxies. We publish here the list of all clusters with their basic parameters, and discuss some illustrative examples in more detail. The full FSVS Cluster Catalogue, together with images and lists of member galaxies etc., will be issued as part of the 'NOAO (National Optical Astronomy Observatories) data products', and accessible at http://www.noao.edu/dpp/ . We describe the format of these data and access to them.
- ID:
- ivo://CDS.VizieR/J/ApJ/854/73
- Title:
- Full-data results of HFF: galaxies z~6-9
- Short Name:
- J/ApJ/854/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present UV luminosity functions of dropout galaxies at z~6-10 with the complete Hubble Frontier Fields data. We obtain a catalog of ~450 dropout-galaxy candidates (350, 66, and 40 at z~6-7, 8, and 9, respectively), with UV absolute magnitudes that reach ~-14mag, ~2 mag deeper than the Hubble Ultra Deep Field detection limits. We carefully evaluate number densities of the dropout galaxies by Monte Carlo simulations, including all lensing effects such as magnification, distortion, and multiplication of images as well as detection completeness and contamination effects in a self-consistent manner. We find that UV luminosity functions at z~6-8 have steep faint-end slopes, {alpha}~-2, and likely steeper slopes, {alpha}<~-2 at z~9-10. We also find that the evolution of UV luminosity densities shows a non-accelerated decline beyond z~8 in the case of M_trunc_=-15, but an accelerated one in the case of M_trunc_=-17. We examine whether our results are consistent with the Thomson scattering optical depth from the Planck satellite and the ionized hydrogen fraction Q_HII_ at z<~7 based on the standard analytic reionization model. We find that reionization scenarios exist that consistently explain all of the observational measurements with the allowed parameters of f_esc_=0.17_-0.03_^+0.07^ and M_trunc_>-14.0 for log{xi}_ion_/[erg^-1^Hz]=25.34, where f_esc_ is the escape fraction, Mtrunc is the faint limit of the UV luminosity function, and {xi}_ion_ is the conversion factor of the UV luminosity to the ionizing photon emission rate. The length of the reionization period is estimated to be {Delta}z=3.9_-1.6_^+2.0^ (for 0.1<Q_HII_<0.99), consistent with the recent estimate from Planck.
- ID:
- ivo://CDS.VizieR/J/ApJS/227/3
- Title:
- Full spectroscopic data release of the SPT-GMOS
- Short Name:
- J/ApJS/227/3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500deg^2^ of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of [OII]{lambda}{lambda}3727, 3729 and H-{delta}, and the 4000{AA} break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m*). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ~20% of the full SPT-SZ sample.
- ID:
- ivo://CDS.VizieR/J/A+A/609/A68
- Title:
- Full-Stokes polarimetry of 5 radio sources
- Short Name:
- J/A+A/609/A68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis pipeline that enables the recovery of reliable information for all four Stokes parameters with high accuracy. Its novelty relies on the effective treatment of the instrumental effects even before the computation of the Stokes parameters, contrary to conventionally used methods such as that based on the Mueller matrix. For instance, instrumental linear polarization is corrected across the whole telescope beam and significant Stokes Q and U can be recovered even when the recorded signals are severely corrupted by instrumental effects. The accuracy we reach in terms of polarization degree is of the order of 0.1-0.2%. The polarization angles are determined with an accuracy of almost 1{def}. The presented methodology was applied to recover the linear and circular polarization of around 150 active galactic nuclei, which were monitored between July 2010 and April 2016 with the Effelsberg 100-m telescope at 4.85GHz and 8.35GHz with a median cadence of 1.2 months. The polarized emission of the Moon was used to calibrate the polarization angle measurements. Our analysis showed a small system-induced rotation of about 1{deg} at both observing frequencies. Over the examined period, five sources have significant and stable linear polarization; three sources remain constantly linearly unpolarized; and a total of 11 sources have stable circular polarization degree m_c_, four of them with non-zero m_c_. We also identify eight sources that maintain a stable polarization angle. All this is provided to the community for future polarization observations reference. We finally show that our analysis method is conceptually different from those traditionally used and performs better than the Mueller matrix method. Although it has been developed for a system equipped with circularly polarized feeds, it can easily be generalized to systems with linearly polarized feeds as well.
- ID:
- ivo://CDS.VizieR/J/ApJ/638/725
- Title:
- Fundamental manifold of spheroids
- Short Name:
- J/ApJ/638/725
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a unifying empirical description of the structural and kinematic properties of all spheroids embedded in dark matter halos. We find that the intracluster stellar spheroidal components of galaxy clusters, which we call cluster spheroids (CSphs) and which are typically 100 times the size of normal elliptical galaxies, lie on a fundamental plane as tight as that defined by elliptical galaxies (rms in effective radius of 0.07) but having a different slope.
- ID:
- ivo://CDS.VizieR/J/MNRAS/397/75
- Title:
- Fundamental Plane analysis in Shapley
- Short Name:
- J/MNRAS/397/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Fundamental Plane (FP) analysis of 141 early-type galaxies in the Shapley supercluster at z=0.049 based on spectroscopy from the AAOmega spectrograph at the Anglo-Australian Telescope and photometry from the WFI on the European Southern Observatory/MPI 2.2-m telescope.
- ID:
- ivo://CDS.VizieR/J/A+AS/140/327
- Title:
- Fundamental plane galaxies redshifts
- Short Name:
- J/A+AS/140/327
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocities and central velocity dispersions are derived for 238 E/S0 galaxies from medium-resolution spectroscopy. New spectroscopic data have been obtained as part of a study of the Fundamental Plane distances and peculiar motions of early-type galaxies in three selected directions of the South Equatorial Strip, undertaken in order to investigate the reality of large-scale streaming motion; results of this study have been reported in Mueller et al. (1998ApJ...507L.105M). The new APM South Equatorial Strip Catalog (-17.5deg<{delta}<+2.5deg) (Raychaudhury & Lynden-Bell, 2000) was used to select the sample of field galaxies in three directions: (1) 15h10-16h10; (2) 20h30-21h50; (3) 00h10-01h30. The spectra obtained have a median S/N per {AA} of 23, an instrumental resolution (FWHM) of ~4{AA}, and the spectrograph resolution (dispersion) is ~100km/s. The Fourier cross-correlation method was used to derive the radial velocities and velocity dispersions. The velocity dispersions have been corrected for the size of the aperture and for the galaxy effective radius. Comparisons of the derived radial velocities with data from the literature show that our values are accurate to 40km/s. A comparison with results from Jorgensen et al. (1995MNRAS.276.1341J) shows that the derived central velocity dispersion have an rms scatter of 0.036 in log{sigma}. There is no offset relative to the velocity dispersions of Davies et al. (1987ApJS...64..581D).
- ID:
- ivo://CDS.VizieR/J/A+A/309/749
- Title:
- Fundamental plane of early type galaxies
- Short Name:
- J/A+A/309/749
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyse the residuals to the fundamental plane (FP) of elliptical galaxies as a function of stellar-population indicators; these are based on the line-strength parameter Mg2 and on UBVRI broad-band colors, and are partly derived from new observations. The effect of the stellar populations accounts for approximately half the observed variation of the mass-to-light ratio responsible for the FP tilt. The residual tilt can be explained by the contribution of two additional effects: the dependence of the rotational support, and possibly that of the spatial structure, on the luminosity. We conclude to a constancy of the dynamical-to-stellar mass ratio. This probably extends to globular clusters as well, but the dominant factor would be here the luminosity dependence of the structure rather than that of the stellar population. This result also implies a constancy of the fraction of dark matter over all the scalelength covered by stellar systems. Our compilation of internal stellar kinematics of galaxies is appended.
