- ID:
- ivo://CDS.VizieR/VIII/87
- Title:
- The Allen Telescope Array 20cm Survey (ATATS). I.
- Short Name:
- VIII/87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the Allen Telescope Array Twenty-centimeter Survey (ATATS), a multi-epoch (12 visits), 690deg^2^ radio image and catalog at 1.4GHz. The survey is designed to detect rare, very bright transients as well as to verify the capabilities of the ATA to form large mosaics. The combined image using data from all 12 ATATS epochs has rms noise {sigma}=3.94mJy/beam and dynamic range 180, with a circular beam of 150" FWHM. It contains 4408 sources to a limiting sensitivity of 5{sigma}=20mJy/beam. We compare the catalog generated from this 12 epoch combined image to the NRAO VLA Sky Survey (NVSS), a legacy survey at the same frequency, and find that we can measure source positions to better than ~20". For sources above the ATATS completeness limit, the median flux density is 97% of the median value for matched NVSS sources, indicative of an accurate overall flux calibration. We examine the effects of source confusion due to the effects of differing resolution between ATATS and NVSS on our ability to compare flux densities. We detect no transients at flux densities greater than 40mJy in comparison with NVSS and place a 2{sigma} upper limit of 0.004deg^-2^ on the transient rate for such sources. These results suggest that the >~1Jy transients reported by Matsumara et al. may not be true transients, but rather variable sources at their flux density threshold.
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- ID:
- ivo://CDS.VizieR/J/ApJS/188/123
- Title:
- The Bolocam Galactic Plane Survey. II.
- Short Name:
- J/ApJS/188/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 8358 sources extracted from images produced by the Bolocam Galactic Plane Survey (BGPS). The BGPS is a survey of the millimeter dust continuum emission from the northern Galactic plane. The catalog sources are extracted using a custom algorithm, Bolocat, which was designed specifically to identify and characterize objects in the large-area maps generated from the Bolocam instrument. The catalog products are designed to facilitate follow-up observations of these relatively unstudied objects. The catalog is 98% complete from 0.4Jy to 60Jy over all object sizes for which the survey is sensitive (<3.5'). We find that the sources extracted can best be described as molecular clumps-large dense regions in molecular clouds linked to cluster formation. We find that the flux density distribution of sources follows a power law with dN/dS{prop.to}S^-2.4+/-0.1^ and that the mean Galactic latitude for sources is significantly below the midplane: <b>=(-0.095+/-0.001{deg}).
- ID:
- ivo://CDS.VizieR/J/MNRAS/182/273
- Title:
- The 5C6 and 5C7 surveys of radio sources.
- Short Name:
- J/MNRAS/182/273
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains the 5C6 and 5C7 radio surveys at 408 and 1407 MHz done with the with the One-Mile telescope at Cambridge (UK). The 5C6 survey of radio sources, made at 408 MHz (HPBW 80"x151") and 1407 MHz (HPBW 23"x44") was centered on 02:14 +32:00' (B1950) and contains 297 sources stronger than 10 mJy at 408 MHz and 1.5 mJy at 1407 MHz. The flux densities are on the KPW scale (Kellermann et al. 1969ApJ...157....1K) and were based on 3C147 and 3C380. Positions, positional errors, flux density information, and descriptions of optical objects visible on the Palomar Sky Survey within about 20" of the radio sources are given. The 5C7 survey of radio sources, made at 408 MHz (HPBW 80"x176") and 1407 MHz (HPBW 23"x51") was centered at 08:17 +27:00 (B1950) and contains 281 sources stronger than 10 mJy at 408 MHz and 1.5 mJy at 1407 MHz. The flux densities are on the KPW scale (Kellermann et al. 1969ApJ...157....1K), and were based on 3C147 and 3C380. Positions, positional errors, flux density information, and descriptions of optical objects visible on the Palomar Sky Survey within about 20" of the radio sources are given.
- ID:
- ivo://CDS.VizieR/J/AJ/153/113
- Title:
- The CGPS 1420 MHz catalog of compact sources
- Short Name:
- J/AJ/153/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of compact sources of radio emission at 1420MHz in the northern Galactic plane from the Canadian Galactic Plane Survey. The catalog contains 72758 compact sources with an angular size less than 3' within the Galactic longitude range 52{deg}<l<192{deg} down to a 5{sigma} detection level of ~1.2mJy. Linear polarization properties are included for 12368 sources with signals greater than 4{sigma}_QU_ in the Canadian Galactic Plane Survey (CGPS) Stokes Q and U images at the position of the total intensity peak. We compare CGPS flux densities with cataloged flux densities in the Northern VLA Sky Survey catalog for 10897 isolated unresolved sources with CGPS flux density greater than 4mJy to search for sources that show variable flux density on timescales of several years. We identify 146 candidate variables that exhibit high fractional variations between the two surveys. In addition, we identify 13 candidate transient sources that have CGPS flux density above 10mJy but are not detected in the Northern VLA Sky Survey.
- ID:
- ivo://CDS.VizieR/J/MNRAS/171/475
- Title:
- The 5C5 survey of radio sources.
- Short Name:
- J/MNRAS/171/475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains the 5C5 survey of radio sources, one of a series of deep surveys made at 408 MHz (HPBW 80"x109") and 1407 MHz (HPBW 23"x31") with the One-Mile telescope at Cambridge. The 5C5 survey was centered on 09h40m+47d (B1950) and contains 252 sources stronger than 8.7 mJy at 408 MHz and 1.8 mJy at 1407 MHz. The flux densities are on the KPW scale (Kellermann et al. 1969ApJ...157....1K), and were based on 3C48. This table was originally published in Pearson, T.J (1975MNRAS.171..475P)
- ID:
- ivo://CDS.VizieR/J/ApJ/718/587
- Title:
- The Fermi-AT20G catalog
- Short Name:
- J/ApJ/718/587
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The high-frequency radio sky, like the gamma-ray sky surveyed by the Fermi satellite, is dominated by flat spectrum radio quasars and BL Lac objects at bright flux levels. To investigate the relationship between radio and gamma-ray emission in extragalactic sources, we have cross-matched the Australia Telescope 20 GHz survey catalog (AT20G) with the Fermi-LAT 1 year Point Source Catalog (1FGL). The 6.0sr of sky covered by both catalogs (DEC<0{deg},|b|>1.5{deg}) contains 5890 AT20G radio sources and 604 1FGL gamma-ray sources. The AT20G source positions are accurate to within ~1 arcsec and, after excluding known Galactic sources, 43% of Fermi 1FGL sources have an AT20G source within the 95% Fermi confidence ellipse. Monte Carlo tests imply that at least 95% of these matches are genuine associations. Only five gamma-ray sources (1% of the Fermi catalog) have more than one AT20G counterpart in the Fermi error box. The AT20G matches also generally support the active galactic nucleus (AGN) associations in the First LAT AGN Catalog. We find a trend of increasing gamma-ray flux density with 20GHz radio flux density. The Fermi detection rate of AT20G sources is close to 100% for the brightest 20GHz sources, decreasing to 20% at 1Jy, and to roughly 1% at 100mJy. Eight of the matched AT20G sources have no association listed in 1FGL and are presented here as potential gamma-ray AGNs for the first time. We also identify an alternative AGN counterpart to one 1FGL source. The percentage of Fermi sources with AT20G detections decreases toward the Galactic plane, suggesting that the 1FGL catalog contains at least 50 Galactic gamma-ray sources in the southern hemisphere that are yet to be identified.
- ID:
- ivo://CDS.VizieR/J/AJ/128/1646
- Title:
- The Galactic Center region at 330MHz
- Short Name:
- J/AJ/128/1646
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a wide-field, subarcminute-resolution VLA image of the Galactic center region at 330MHz. With a resolution of ~7"x12" and an rms noise of 1.6mJy/beam, this image represents a significant increase in resolution and sensitivity over the previously published VLA image at this frequency. The improved sensitivity has more than tripled the census of small-diameter sources in the region, has resulted in the detection of two new nonthermal filaments (NTFs), 18 NTF candidates, and 30 pulsar candidates, reveals previously known extended sources in greater detail, and has resulted in the first detection of Sagittarius A* in this frequency range.
- ID:
- ivo://CDS.VizieR/J/A+A/598/A78
- Title:
- The GMRT 150MHz all-sky radio survey
- Short Name:
- J/A+A/598/A78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first full release of a survey of the 150MHz radio sky, observed with the Giant Metrewave Radio Telescope (GMRT) between April 2010 and March 2012 as part of the TIFR GMRT Sky Survey (TGSS) project. Aimed at producing a reliable compact source survey, our automated data reduction pipeline efficiently processed more than 2000h of observations with minimal human interaction. Through application of innovative techniques such as image-based flagging, direction-dependent calibration of ionospheric phase errors, correcting for systematic offsets in antenna pointing, and improving the primary beam model, we created good quality images for over 95 percent of the 5336 pointings. Our data release covers 36900deg^2^ (or 3.6{pi}steradians) of the sky between -53{deg} and +90{deg} declination (Dec), which is 90 percent of the total sky. The majority of pointing images have a noise level below 5mJy/beam with an approximate resolution of 25"x25" (or 25"x25"/cos(Dec-19{deg}) for pointings south of 19{deg} declination). We have produced a catalog of 0.62 Million radio sources derived from an initial, high reliability source extraction at the seven sigma level. For the bulk of the survey, the measured overall astrometric accuracy is better than two arcseconds in right ascension and declination, while the flux density accuracy is estimated at approximately ten percent. Within the scope of the TGSS alternative data release (TGSS ADR) project, the source catalog, as well as 5336 mosaic images (5{deg}x5{deg}) and an image cutout service, are made publicly available at the CDS as a service to the astronomical community. Next to enabling a wide range of different scientific investigations, we anticipate that these survey products will provide a solid reference for various new low-frequency radio aperture array telescopes (LOFAR, LWA, MWA, SKA-low), and can play an important role in characterizing the epoch-of-reionisation (EoR) foreground. The TGSS ADR project aims at continuously improving the quality of the survey data products. Near-future improvements include replacement of bright source snapshot images with archival targeted observations, using new observations to fill the holes in sky coverage and replace very poor quality observational data, and an improved flux calibration strategy for less severely affected observational data.
- ID:
- ivo://CDS.VizieR/VIII/53
- Title:
- The Green Bank Survey
- Short Name:
- VIII/53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog presents the parts I, II, and III of the Green Bank survey of extragalactic radio sources at 1400 MHz. The data were obtained with the 300' antenna, producing a beamwidth of 10'x11' FWHM. Part I of the survey covers about 521 square degrees of the sky with RA from 7h17m to 16h23m, DEC from +45.8{deg} to +51.7{deg}. 1086 sources are presented down to a limiting flux density of 90 mJy. These data were originally published in Maslowski, 1972, Acta Astronomica, 22, 227 (1972AcA....22..227M). Part II of the survey covers 0.28 sr of the sky with RA from 7h08m to 16h57m, DEC from +31.9{deg} to +39.7{deg}. 2022 sources are presented down to a limiting flux density of 0.09 mJy. Spectral indices between 1400 MHz and 408 MHz are determined for most sources by comparison with the B2 source catalog (Cat.<VIII/36>). These data were originally published in Machalski 1978, Acta Astronomica, 28, 367 (1978AcA....28..367M) Part III of the survey covers an area of 0.099 sr at declinations between 70 and 76.8 degrees. This catalog contains a total of 676 radio sources, of which 502 are statistically complete to 112 mJy. These data were originally published as Rys and Machalski, 1987, Acta Astronomica, 37, 163 (1987AcA....37..163R).
- ID:
- ivo://CDS.VizieR/J/ApJ/844/78
- Title:
- The high-redshift COBRA survey: IRAC obs.
- Short Name:
- J/ApJ/844/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 190 galaxy cluster candidates (most at high redshift) based on galaxy overdensity measurements in the Spitzer/IRAC imaging of the fields surrounding 646 bent, double-lobed radio sources drawn from the Clusters Occupied by Bent Radio AGN (COBRA) Survey. The COBRA sources were chosen as objects in the Very Large Array FIRST survey that lack optical counterparts in the Sloan Digital Sky Survey to a limit of m_r_=22, making them likely to lie at high redshift. This is confirmed by our observations: the redshift distribution of COBRA sources with estimated redshifts peaks near z=1 and extends out to z~3. Cluster candidates were identified by comparing our target fields to a background field and searching for statistically significant (>=2{sigma}) excesses in the galaxy number counts surrounding the radio sources; 190 fields satisfy the >=2{sigma} limit. We find that 530 fields (82.0%) have a net positive excess of galaxies surrounding the radio source. Many of the fields with positive excesses but below the 2{sigma} cutoff are likely to be galaxy groups. Forty-one COBRA sources are quasars with known spectroscopic redshifts, which may be tracers of some of the most distant clusters known.
