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1891. Westerbork observations of Galactic Sources
ID:
ivo://CDS.VizieR/J/A+AS/43/1
Title:
Westerbork observations of Galactic Sources
Short Name:
J/A+AS/43/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a search for new Galactic sources from the BG catalogue (Fanti et al., 1974A&AS...16...43F). The observations were made with the Westerbork Synthesis Radiotelescope operating at 1.4GHz, using the short cuts technique. The adopted selection criteria for the observed sample are discussed in detail. For reducing the data we have adopted the Clean and Restore technique. We have also tested the capability of this technique in reproducing the total flux density for the very extended structures. A catalogue of the sources present in each field was produced ; the relevant information about observations and reduction characteristics are given.
1892. Westerbork Second Deep Survey
ID:
ivo://CDS.VizieR/J/A+A/35/393
Title:
Westerbork Second Deep Survey
Short Name:
J/A+A/35/393
Date:
21 Oct 2021
Publisher:
CDS
Description:
A radio survey has been made of an area centered at 01h 03min +29{deg}, using the Westerbork telescope at 1415MHz. The completeness limit of the survey is 7mJy. Additional observations have been made at 610MHz. The Lick 120" telescope has been used to obtain deep (O98-O2 emulsion) plates to serve as an optical counterpart. A catalogue is presented of 58 sources found in the survey. 53 of these comprise a complete sample. 31 sources of the complete sample lie in areas of which Lick plates were taken. Of the sources in Lick plates areas, 11 could be identified with galaxies and 3 with possible QSO's, yielding an identification percentage of 46. For the other 22 sources an identification programme was carried out using Palomar Sky Survey prints and other large 48" Schmidt plates: three of these sources could be identified with galaxies and two with possible QSO's. The survey was also used to derive source counts and a spectral index distribution. The source counts agree well with those derived for an earlier survey. The spectral index distribution has a mean of 0.52 and a width of 0.39. the explanation for the flatter spectra is not clear but might possibly lie in another source population that begins to dominate the results at low flux densities.
1893. Westerhout's Catalogue of 82 Discrete Sources
ID:
ivo://CDS.VizieR/VIII/64
Title:
Westerhout's Catalogue of 82 Discrete Sources
Short Name:
VIII/64
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalogue was created based on the original published catalogue in the article by Westerhout G., 1958, Bull. Astron. Inst. Netherlands, vol.14, p.215, "A Survey of the Continuous Radiation from the Galactic System at a Frequency of 1390 Mc/s." His article describes the results of a survey of the radiation along the galactic ridge and a search for discrete sources. The observations were made with the 25-m radio telescope at Dwingeloo, which has a beamwidth of 0.57 degree at a frequency of 1390 Mc/s. The catalogue contains positions of 82 discrete sources. The epoch for positions in the original published catalogue was 1957.0. Positions referred to 2000.0 are shown in this machine-readable catalogue.
1894. Westerlund 1 reduced images of radio emission
ID:
ivo://CDS.VizieR/J/A+A/632/A38
Title:
Westerlund 1 reduced images of radio emission
Short Name:
J/A+A/632/A38
Date:
21 Oct 2021
Publisher:
CDS
Description:
Massive stars and their stellar winds are important for a number of feedback processes. The mass lost in the stellar wind can help determine the end-point of the star as a neutron star (NS) or a black hole (BH). However, the impact of mass loss on the post-main sequence evolutionary stage of massive stars is not well understood. Westerlund 1 is an ideal astrophysical laboratory in which to study massive stars and their winds in great detail over a large range of different evolutionary phases. We aim to study the radio emission from Westerlund 1, in order to measure radio fluxes from the population of massive stars, and determine the mass-loss rates and spectral indices where possible. Observations were carried out in 2015 and 2016 with the Australia Telescope Compact Array (ATCA) at 5.5 and 9GHz using multiple configurations, with maximum baselines ranging from 750m to 6km. Thirty stars are detected in the radio from the fully concatenated dataset, ten of which are Wolf Rayet stars (WRs) (predominantly late type WN stars), five yellow hypergiants (YHGs), four red supergiants (RSGs), one luminous blue variable (LBV), the sgB[e] star W9, and several OB supergiants. New source detections in the radio are found for the WR stars, and five OB supergiants. These detections lead to evidence for three new OB supergiant binary candidates, which is inferred from derived spectral index limits. Spectral indices and index limits were determined for massive stars in Westerlund 1. For cluster members found to have partially optically thick emission, mass-loss rates were calculated. Under the approximation of a thermally emitting stellar wind and a steady mass-loss rate, clumping ratios were then estimated for eight WRs. Diffuse radio emission was detected throughout the cluster. Detections of knots of radio emission with no known counterparts indicate the highly clumped structure of this intra-cluster medium, likely shaped by a dense cluster wind.
1895. WISE candidate {gamma}-ray blazar radio sources
ID:
ivo://CDS.VizieR/J/ApJS/215/14
Title:
WISE candidate {gamma}-ray blazar radio sources
Short Name:
J/ApJS/215/14
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of radio-loud candidate {gamma}-ray emitting blazars with WISE mid-infrared colors similar to the colors of confirmed {gamma}-ray blazars. The catalog is assembled from WISE sources detected in all four WISE filters, with colors compatible with the three-dimensional locus of the WISE {gamma}-ray emitting blazars, and which can be spatially cross-matched with radio sources from one of the three radio surveys: NVSS, FIRST, and/or SUMSS. Our initial WISE selection uses a slightly modified version of previously successful algorithms. We then select only the radio-loud sources using a measure of the radio-to-IR flux, the q_22_parameter, which is analogous to the q_24_ parameter known in the literature but which instead uses the WISE band-four flux at 22{mu}m. Our final catalog contains 7855 sources classified as BL Lacs, FSRQs, or mixed candidate blazars; 1295 of these sources can be spatially re-associated as confirmed blazars. We describe the properties of the final catalog of WISE blazar-like radio-loud sources and consider possible contaminants. Finally, we discuss why this large catalog of candidate {gamma}-ray emitting blazars represents a new and useful resource to address the problem of finding low-energy counterparts to currently unidentified high-energy sources.
1896. WIYN spectroscopy in the deep SWIRE field
ID:
ivo://CDS.VizieR/J/ApJS/182/625
Title:
WIYN spectroscopy in the deep SWIRE field
Short Name:
J/ApJS/182/625
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of spectroscopy using HYDRA on the WIYN 3.5m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24um. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z<0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10:46:00, +59:01:00 (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20cm detections, 24m detections, galaxies with r<20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r<19 were observed including all of the radio sources and most of the 24um sources with r<20 and a sample of radio sources which had fainter optical counterparts on the r-band image.
1897. WMAP cosmic microwave background data
ID:
ivo://CDS.VizieR/J/A+A/557/L1
Title:
WMAP cosmic microwave background data
Short Name:
J/A+A/557/L1
Date:
21 Oct 2021
Publisher:
CDS
Description:
There is currently a debate over the existence of claimed statistical anomalies in the cosmic microwave background (CMB), recently confirmed in Planck data. Recent work has focussed on methods for measuring statistical significance, on masks and on secondary anisotropies as potential causes of the anomalies. We investigate simultaneously the method for accounting for masked regions and the foreground integrated Sachs-Wolfe (ISW) signal. We search for trends in different years of WMAP CMB data with different mask treatments. We reconstruct the ISW field due to the 2 Micron All-Sky Survey (2MASS) and the NRAO VLA Sky Survey (NVSS) up to l=5, and we focus on the Axis of Evil (AoE) statistic and even/odd mirror parity, both of which search for preferred axes in the Universe. We find that removing the ISW reduces the significance of these anomalies in WMAP data, though this does not exclude the possibility of exotic physics. In the spirit of reproducible research, all reconstructed maps and codes will be made available for download at http://www.cosmostat.org/anomaliesCMB.html .
1898. WMAP five-year source catalog
ID:
ivo://CDS.VizieR/J/ApJS/180/283
Title:
WMAP five-year source catalog
Short Name:
J/ApJS/180/283
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the list of point sources found in the Wilkinson Microwave Anisotropy Probe (WMAP) five-year maps. The technique used in the first-year and three-year analyses now finds 390 point sources, and the five-year source catalog is complete for regions of the sky away from the Galactic plane to a 2Jy limit, with SNR>4.7 in all bands in the least covered parts of the sky. The noise at high frequencies is still mainly radiometer noise, but at low frequencies the cosmic microwave background (CMB) anisotropy is the largest uncertainty. A separate search of CMB-free V-W maps finds 99 sources of which all but one can be identified with known radio sources. The sources seen by WMAP are not strongly polarized. Many of the WMAP sources show significant variability from year to year, with more than a 2:1 range between the minimum and maximum fluxes.
1899. WMAP observations of Planck ESZ clusters
ID:
ivo://CDS.VizieR/J/ApJ/771/137
Title:
WMAP observations of Planck ESZ clusters
Short Name:
J/ApJ/771/137
Date:
21 Oct 2021
Publisher:
CDS
Description:
We examine the Sunyaev-Zeldovich (SZ) effect in the seven year Wilkinson Microwave Anisotropy Probe (WMAP) data by cross-correlating it with the Planck Early-release Sunyaev-Zeldovich catalog (Cat. VIII/88/esz). Our analysis proceeds in two parts. We first perform a stacking analysis in which the filtered WMAP data are averaged at the locations of the 175 Planck clusters. We then perform a regression analysis to compare the mean amplitude of the SZ signal, Y_500_, in the WMAP data to the corresponding amplitude in the Planck data. The aggregate Planck clusters are detected in the seven year WMAP data with a signal-to-noise ratio of 16.3. In the regression analysis, we find that the SZ amplitude measurements agree to better than 25%: a=1.23+/-0.18 for the fit Y_500_^wmap^=aY_500_^planck^.
1900. WMAP point sources at 61 and 94GHz
ID:
ivo://CDS.VizieR/J/MNRAS/428/3048
Title:
WMAP point sources at 61 and 94GHz
Short Name:
J/MNRAS/428/3048
Date:
21 Oct 2021
Publisher:
CDS
Description:
The detection of point sources in cosmic microwave background maps is usually based on a single-frequency approach, whereby maps at each frequency are filtered separately and the spectral information on the sources is derived combining the results at the different frequencies. In contrast, in the case of multifrequency detection methods, source detection and spectral information are tightly interconnected in order to increase the source detection efficiency. In this work we apply the matched multifiltermethod to the detection of point sources in the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year data at 61 and 94GHz. This linear filtering technique takes into account the spatial and the cross-power spectrum information at the same time using the spectral behaviour of the sources without making any a priori assumption about it.