- ID:
- ivo://CDS.VizieR/J/A+A/549/A133
- Title:
- Bright northern radio sources with VLA/JVLA
- Short Name:
- J/A+A/549/A133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report multiple epoch VLA/JVLA observations of 89 northern hemisphere sources, most with 37GHz flux density >1Jy, observed at 4.8, 8.5, 33.5, and 43.3GHz. The high frequency selection leads to a predominantly flat spectrum sample, with 85% of our sources being in the Planck Early Release Compact Source Catalog (ERCSC, Cat. VIII/88). These observations allow us to: 1) validate Planck's 30 and 44GHz flux density scale; 2) extend the radio spectral energy distributions of Planck sources to lower frequencies allowing for the full 5-857GHz regime to be studied; and 3) characterize the variability of these sources. At 30GHz and 44GHz, the JVLA and Planck flux densities agree to within ~3%. On timescales of less than two months the median variability of our sources is 2%. On timescales of about a year the median variability increases to 14%. Using the WMAP 7-year data, the 30GHz median variability on a 1-6 years timescale is 16%.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/204/151
- Title:
- Bright radio sources at 178 MHz (3CRR)
- Short Name:
- J/MNRAS/204/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A revised sample of bright radio sources at 178MHz is defined in order to correct the biases introduced into the 3CR catalog by confusion and partial resolution. The sample is shown to be 96 percent complete to a flux-density limit of 10Jy for sources smaller than 10arcmin. The bias of the 3CR catalog against objects of larger angular size is also reduced. Optical identifications are presented for 96 percent of the sources, 71 percent with galaxies and 25 percent with quasars. The radio-galaxy population is found to show strong space-density evolution for luminosities in excess of approximately 10^26.5^W/Hz/sr at 178MHz (redshifts greater than or approximately equal to 0.2), while the evolutionary properties of galaxies and quasars of the same luminosity and redshift are very similar.
- ID:
- ivo://CDS.VizieR/J/ApJS/126/209
- Title:
- Bright SHARC survey cluster catalog
- Short Name:
- J/ApJS/126/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Bright SHARC (Serendipitous High-Redshift Archival ROSAT Cluster) Survey, which is an objective search for serendipitously detected extended X-ray sources in 460 deep ROSAT PSPC pointings. The Bright SHARC Survey covers an area of 178.6 deg^2^ and has yielded 374 extended sources. We discuss the X-ray data reduction, the candidate selection and present results from our on-going optical follow-up campaign. The optical follow-up concentrates on the brightest 94 of the 374 extended sources and is now 97% complete. We have identified 37 clusters of galaxies, for which we present redshifts and luminosities. The clusters span a redshift range of 0.0696<z<0.83 and a luminosity range of 0.065<L_X_< 8.3x10^44^ergs/s [0.5-2.0keV] (assuming H_0_=50km/s/Mpc and q_0_=0.5). Twelve of the clusters have redshifts greater than z=0.3, eight of which are at luminosities brighter than L_X_=3x10^44^ergs/s. Seventeen of the 37 optically confirmed Bright SHARC clusters have not been listed in any previously published catalog. We also report the discovery of three candidate "fossil groups" of the kind proposed by Ponman et al. (1994Natur.369..462P)
- ID:
- ivo://CDS.VizieR/J/AJ/135/1567
- Title:
- Bright star clusters in M51
- Short Name:
- J/AJ/135/1567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of star clusters with V_F555W_<23mag detected in the interacting spiral galaxy M51 system based on mosaic images taken with the Hubble Space Telescope Advanced Camera for Surveys by the Hubble Heritage Team. We have selected about 3600 clusters based on their morphological information through visual inspection. The final star cluster catalog includes 2224 clusters that are relatively well isolated and have a circular shape.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A15
- Title:
- Broad absorption line quasars in LDR1
- Short Name:
- J/A+A/622/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the low-frequency radio properties of broad absorption line quasars (BALQSOs) from the LOFAR Two-metre Sky-Survey Data Release 1 (LDR1). The value-added LDR1 catalogue contains Pan-STARRS counterparts, which we match with the Sloan Digital Sky Survey (SDSS) DR7 and DR12 quasar catalogues. We find that BALQSOs are twice as likely to be detected at 144MHz than their non-BAL counterparts, and BALQSOs with low-ionisation species present in their spectra are three times more likely to be detected than those with only high-ionisation species. The BALQSO fraction at 144MHz is constant with increasing radio luminosity, which is inconsistent with previous results at 1.4GHz, indicating that observations at the different frequencies may be tracing different sources of radio emission. We cross-match radio sources between the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) survey and LDR1, which provides a bridge via the LDR1 Pan-STARRS counterparts to identify BALQSOs in SDSS. Consequently we expand the sample of BALQSOs detected in FIRST by a factor of three. The LDR1-detected BALQSOs in our sample are almost exclusively radio-quiet (logr<2), with radio sizes at 144$\,$MHz typically less than 200kpc these radio sizes tend to be larger than those at 1.4GHz, suggesting more extended radio emission at low frequencies. We find that although the radio detection fraction increases with increasing balnicity index (BI), there is no correlation between BI and either low-frequency radio power or radio-loudness. This suggests that both radio emission and BI may be linked to the same underlying process, but are spatially distinct phenomena.
- ID:
- ivo://CDS.VizieR/J/ApJ/821/33
- Title:
- Broad H{beta} emission line in 102 Seyfert galaxies
- Short Name:
- J/ApJ/821/33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 102 local (0.02=<z=<0.1) Seyfert galaxies with black hole masses M_BH_>10^7^M_{sun}_ was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between M_BH_ and host galaxy properties. We study profile changes of the broad H{beta} emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad H{beta} emission line is of particular interest, not only because it is used to estimate M_BH_, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-line variability (in either width or flux) is observed in the majority (~66%) of the objects, resulting in a Seyfert-type change for ~38% of the objects, likely driven by variable accretion and/or obscuration. The broad H{beta} line virtually disappears in 3/102 (~3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of H{beta} line variability in a sample of low-redshift Seyfert galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/454/453
- Title:
- BR photometry and redshifts of IDS galaxies
- Short Name:
- J/A+A/454/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IRAS Deep Survey (IDS) of the North Ecliptic Pole region remains one of the deepest complete far-infrared-selected galaxy samples available. ISOCAM observations in the LW3 filter (12-18{mu}m) of 3.2'x3.2' fields centered on the nominal positions of 94 out of the 98 IDS sources yielding 116 ISOCAM detections. The resulting sample has allowed us to assess the source reliability, identify confusion effects, and pinpoint optical counterparts. To fully exploit the potential of this sample for investigating galaxy evolution, we carried out optical observations of candidate identifications to 100 out of the 116 ISOCAM sources. Optical imaging was acquired for 88 galaxies in 54 IDS fields: 44 galaxies were imaged in both the B- and the R-band, 33 only in the R-band, and 11 only in the B-band. These observations aimed at extending the MIR/FIR spectral energy distribution to the optical region and achieving morphological information. In addition, spectra were obtained for 65 IDS fields, 20 of which had not been observed before. Redshifts were measured for the 85 galaxies found within the positional error circles of 77 ISOCAM sources detected in those IDS fields.
- ID:
- ivo://CDS.VizieR/J/AJ/117/75
- Title:
- BR photometry in Coma, A2199 & AWM5 clusters
- Short Name:
- J/AJ/117/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study on galaxy interactions, tides, and other processes that produce luminous fine-scale substructures in the galaxy clusters: Coma, Perseus, Abell 2199, AWM 3, and AWM 5. All unusual structures in these clusters can be categorized into seven morphologies: interacting galaxies, multiple galaxies (noninteracting), distorted galaxies, tailed galaxies, line galaxies, dwarf galaxy groups, and galaxy aggregates. The various morphologies are described, and a catalog is presented, of 248 objects in these five clusters along with color, and positional information obtained from CCD images taken with the WIYN 3.5 m telescope in broadband B and R filters.
- ID:
- ivo://CDS.VizieR/J/PASP/110/533
- Title:
- BR photometry of Fornax bright stars
- Short Name:
- J/PASP/110/533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present accurate photometry on the Johnson B, Kron-Cousins R photometric system for approximately 100,000 stars in a 1/3deg^2^ field centered on the dwarf spheroidal galaxy in Fornax. We identify numerous probable short-period variable stars, blue stars that appear to be the main sequence of a small population with an age of order 108yr, and two distinct types of luminous red star: an extended sequence of primarily carbon stars and a clump of mostly M giants slightly more luminous than the giant-branch tip. The spatial distribution of each of these subpopulations within the Fornax dwarf galaxy is considered.
- ID:
- ivo://CDS.VizieR/J/AJ/131/912
- Title:
- BR photometry of Fornax dSph center
- Short Name:
- J/AJ/131/912
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have imaged the recently discovered stellar overdensity located approximately one core radius from the center of the Fornax dwarf spheroidal galaxy using the Magellan Clay 6.5m telescope with the Magellan Instant Camera. Superb seeing conditions allowed us to probe the stellar populations of this overdensity and of a control field within Fornax to a limiting magnitude of R=26. The color-magnitude diagram of the overdensity field is virtually identical to that of the control field, with the exception of the presence of a population arising from a very short (less than 300Myr in duration) burst of star formation 1.4Gyr ago.
