- ID:
- ivo://CDS.VizieR/J/A+A/383/823
- Title:
- Radial velocities of UCOs in Fornax
- Short Name:
- J/A+A/383/823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between the Ultra Compact Objects (hereafter UCOs) recently discovered in the Fornax cluster (Drinkwater et al., 2000PASA...17..227D; Hilker et al., 1999, Cat. <J/A+AS/134/75>) and the brightest globular clusters associated with the central galaxy NGC 1399 has been investigated. A spectroscopic survey on compact objects in the central region of the Fornax cluster was carried out with the 2.5 m du Pont telescope (LCO) at Las Campanas, in the three nights of 2000/12/30 to 2001/01/01. The magnitude limit was approx. V=21 mag, the spectral resolution approx. 4{AA}. UCOs and the bright NGC 1399 globular clusters with similar brightness were inspected. 12 GCs from the bright end of the globular cluster luminosity function have been identified as Fornax members. Eight are new members, four were known as members from before.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/703/285
- Title:
- Radio and IR counterparts of BLAST sources in CDFS
- Short Name:
- J/ApJ/703/285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified radio and/or mid-infrared counterparts to 198 out of 350 sources detected at >=5{sigma} over ~9deg^2^ centered on the Chandra Deep Field South by the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) at 250, 350, and 500um. We have matched 114 of these counterparts to optical sources with previously derived photometric redshifts and fitted spectral energy distributions to the BLAST fluxes and fluxes at 70 and 160um acquired with the Spitzer Space Telescope. In this way, we have constrained dust temperatures, total far-infrared/submillimeter luminosities, and star formation rates for each source. Our findings show that, on average, the BLAST sources lie at significantly lower redshifts and have significantly lower rest-frame dust temperatures compared to submillimeter sources detected in surveys conducted at 850um. We demonstrate that an apparent increase in dust temperature with redshift in our sample arises as a result of selection effects. Finally, we provide the full multiwavelength catalog of >=5{sigma} BLAST sources contained within the complete ~9deg^2^ survey area.
- ID:
- ivo://CDS.VizieR/J/ApJ/645/890
- Title:
- Radio and X-ray-emitting broad-line AGNs
- Short Name:
- J/ApJ/645/890
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derived the black hole fundamental plane relationship between the 1.4GHz radio luminosity (Lr), 0.1-2.4keV X-ray luminosity (LX), and black hole mass (M) from a uniform broad-line SDSS AGN sample including both radio-loud and radio-quiet X-ray-emitting sources. We found in our sample that the fundamental plane relation has a very weak dependence on the black hole mass, and a tight correlation also exists between the Eddington-luminosity-scaled X-ray and radio luminosities for the radio-quiet subsample. In addition, we noticed that the radio-quiet and radio-loud AGNs have different power-law slopes in the radio-X-ray nonlinear relationship. The radio-loud sample displays a slope of 1.39, which seems consistent with the jet-dominated X-ray model. However, it may also be partly due to the relativistic beaming effect. For the radio-quiet sample the slope of the radio-X-ray relationship is about 0.85, which is possibly consistent with the theoretical prediction from the accretion-flow-dominated X-ray model. We briefly discuss the reason why our derived relationship is different from some previous works and expect the future spectral studies in radio and X-ray bands on individual sources in our sample to confirm our result.
- ID:
- ivo://CDS.VizieR/J/MNRAS/478/3848
- Title:
- Radio-emitting AGN environmental prop.
- Short Name:
- J/MNRAS/478/3848
- Date:
- 10 Dec 2021 00:52:31
- Publisher:
- CDS
- Description:
- We study the environmental properties of z<=1.2 radio-selected active galactic nuclei (AGNs) belonging to the ~2deg^2^ of the COSMOS field, finding that about 20 per cent of them appear within overdense structures. AGNs with P_1.4GHz_>10^23.5^W/Hz/sr are twice more likely to be found in clusters with respect to fainter sources (~38 per cent vs ~15 per cent), just as radio-selected AGNs with stellar masses M_*_>10^11^M_{sun}_ are twice more likely to be found in overdense environments with respect to objects of lower mass (~24 per cent vs ~11 per cent). Comparisons with galaxy samples further suggest that radio-selected AGN of large stellar mass tend to avoid underdense environments more than normal galaxies with the same stellar content. Stellar masses also seem to determine the location of radio-active AGN within clusters: ~100 per cent of the sources found as satellite galaxies have M_*_<10^11.3^M_{sun}_, while ~100 per cent of the AGNs coinciding with a cluster central galaxy have M_*_>10^11^M_{sun}_. No different location within the cluster is instead observed for AGN of various radio luminosities. Radio AGN, which also emit in the Mid-Infrared show a marked preference to be found as isolated galaxies (~70 per cent) at variance with those also active in the X-ray that all seem to reside within overdensities. What emerges from our work is a scenario whereby physical processes on sub-pc and kpc scales (e.g. emission, respectively, related to the AGN and to star formation) are strongly interconnected with the large-scale environment of the AGN itself.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2237
- Title:
- Radio-excess IR galaxies PMN/FSC sample selection
- Short Name:
- J/AJ/126/2237
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 178 extragalactic objects is defined by correlating the 60{mu}m IRAS Faint Source Catalog (FSC, Cat. <II/156>) with the 5GHz Parkes-MIT-NRAO (PMN, Cat. <VIII/38>) catalog.
- ID:
- ivo://CDS.VizieR/J/ApJS/123/41
- Title:
- Radio galaxies in Las Campanas redshift survey
- Short Name:
- J/ApJS/123/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To increase the redshift range and look-back time over which the radio luminosity function can be measured directly, we identified 1157 galaxies in the Las Campanas Redshift Survey (LCRS, Cat. <VII/203>) having isophotal (red) magnitudes m_ISO_<=18.0 with radio sources brighter than 2.5mJy/beam in the 1.4GHz NRAO VLA Sky Survey (NVSS, 1998AJ....115.1693C). Since the NVSS has 45" FWHM angular resolution, these radio and optical limits include nearly all LCRS galaxies with 1.4GHz luminosities L>=10^22.4^W/Hz at z~0.05 to L>=10^23.6^W/Hz at z~0.2. The mean redshift <z>~0.14 of the radio-detected galaxies is higher than the mean redshift <z>~0.10 of the optical sample. This indicates that, statistically, the radio emission was detected from galaxies with the highest optical luminosities. Of the 1157 galaxies, 261 were also identified with far-infrared (FIR) sources in the IRAS Point Source Catalog and Faint Source Catalog. The principal radio energy sources in all identified galaxies were classified as either "starburst" or "AGN" on the basis of their FIR-radio flux ratios, FIR spectral indices, and radio-optical flux ratios. We show that the radio-optical flux ratio can be effectively used to classify the dominant energy source for the radio emission even if FIR fluxes and radio morphological data are not available.
- ID:
- ivo://CDS.VizieR/J/ApJS/134/355
- Title:
- Radio galaxies in 18 nearby Abell clusters
- Short Name:
- J/ApJS/134/355
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxies in 18 nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3Mpc (H_0_=75km/s/Mpc), which corresponds to 1.5 Abell radii and approximately 4 orders of magnitude in galaxy density. To create a truly useful catalog, we have collected optical spectra for nearly all of the galaxies lacking public velocity measurements. Consequently, we are able to discriminate between those radio galaxies seen in projection on the cluster and those that are in actuality cluster members. The resulting catalog consists of 329 cluster radio galaxies plus 138 galaxies deemed foreground or background objects, and new velocity measurements are reported for 273 of these radio galaxies. The motivation for the catalog is the study of galaxy evolution in the cluster environment. The radio luminosity function is a powerful tool in the identification of active galaxies, as it is dominated by star-forming galaxies at intermediate luminosities and active galactic nuclei (AGNs) at higher luminosities. The flux limit of the NVSS allows us to identify AGNs and star-forming galaxies down to star formation rates less than 1M_{sun}_/yr. This sensitivity, coupled with the all-sky nature of the NVSS, allows us to produce a catalog of considerable depth and breadth. In addition to these data, we report detected infrared fluxes and upper limits obtained from IRAS data. It is hoped that this database will prove useful in a number of potential studies of the effect of environment on galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/A+A/544/A18
- Title:
- Radio galaxies of the local universe
- Short Name:
- J/A+A/544/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first catalog of radio-emitting galaxies that covers the entire sky. Our catalog allows the selection of volume-limited subsamples containing all low-power radio galaxies, similar to the prototypical low-power radio galaxies Cen A or M87, within some hundred Mpc. Over 30% of the galaxies in our catalog are not contained in existing large-area extra-galactic radio samples. We find that the local galaxy density in a sphere of 2Mpc centered on the radio galaxies is 1.7 times higher than around non-radio galaxies of the same luminosity and morphology. This significant enhancement suggests a causal relation between external galaxy properties, such as environment or merger history, and the formation of powerful jets in the present universe. Since the enhancement is observed with respect to galaxies of the same luminosity and Hubble type, it is not primarily driven by black hole mass. Our automated matching procedure is found to select radio-emitting galaxies with high efficiency (99%) and purity (91%).
- ID:
- ivo://CDS.VizieR/J/ApJ/741/30
- Title:
- Radio/{gamma}-ray correlation in AGN
- Short Name:
- J/ApJ/741/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed statistical analysis of the correlation between radio and gamma-ray emission of the active galactic nuclei (AGNs) detected by Fermi during its first year of operation, with the largest data sets ever used for this purpose. We use both archival interferometric 8.4GHz data (from the Very Large Array and ATCA, for the full sample of 599 sources) and concurrent single-dish 15GHz measurements from the Owens Valley Radio Observatory (OVRO, for a sub sample of 199 objects). Our unprecedentedly large sample permits us to assess with high accuracy the statistical significance of the correlation, using a surrogate data method designed to simultaneously account for common-distance bias and the effect of a limited dynamical range in the observed quantities.
- ID:
- ivo://CDS.VizieR/J/ApJ/842/87
- Title:
- Radio luminosity function of FSRQs
- Short Name:
- J/ApJ/842/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the radio luminosity function (LF) of flat-spectrum radio quasars (FSRQ), using the largest and most complete sample to date. Cross-matching between the FIRST 20cm and GB6 6cm radio surveys, we find 638 flat-spectrum radio sources above 220mJy at 1.4GHz; of these, 327 are classified and verified using optical spectroscopy data, mainly from Sloan Digital Sky Survey Data Release 12. We also considered flat-spectrum radio sources that lack both literature references and optical spectroscopy, and we identified 12 out of the 43 such sources to potentially be FSRQs, using their WISE colors. From the fully identified sample of 242 FSRQs, we derived the radio LF and cosmic evolution of blazars at 1.4GHz, finding good agreement with previous work at 5GHz. The number density of FSRQs increases dramatically to a redshift of z~2 and then declines for higher redshifts. Furthermore, the redshift at which the quasar density peaks is clearly dependent on luminosity, with more luminous sources peaking at higher redshifts. The approximate best-fit LF for a luminosity-dependent evolutionary model is a broken power-law with slopes ~0.7 and ~1.7 below and above the break luminosity, logL_1.4_~43.8erg/s, respectively.