데이터셋 상세
미국
7C 151-MHz Low-Declination Survey Catalog
The Cambridge Low Frequency Synthesis Telescope (CLFST) has been used at 151 MHz to survey a region of 1393 square degrees, in the range of RA from 9<sup>h</sup> to 16<sup>h</sup>, and of Dec from 20<sup>o</sup> to 35<sup>o</sup>, with an angular resolution of 108 x 108cosec(Dec) arcsec<sup>2</sup>. The rms noise in the maps is in general ~ 35 - 55 mJy/beam, but varies considerably and exceeds this in some areas. The authors have extracted sources with signal-to-noise ratio > 5.5, a total of 5526 sources, and this table contains the catalog of their positions and flux densities. This table was created by the HEASARC in October 2010 based on CDS table J/MNRAS/282/779 file 7c_low.dat. This is a service provided by NASA HEASARC .
데이터 정보
연관 데이터
Australia Telescope Low-Brightness Survey Source Catalog
공공데이터포털
The Australia Telescope Low-brightness Survey (ATLBS) regions have been mosaic imaged at a radio frequency of 1.4 GHz with 6 arcseconds angular resolution and 72 microJansky per beam (µJy/beam) rms noise. The images (centered at RA 00h 35m 00s, Dec -67o 00' 00" and RA 00h 59m 17s, Dec -67o 00' 00", J2000 epoch) cover 8.42 deg2 sky area and have no artifacts or imaging errors above the image thermal noise. Multi-resolution radio and optical r-band images (made using the 4 m CTIO Blanco telescope) were used to recognize multi-component sources and prepare a source list of 1366 1.4-GHZ sources; the detection threshold was 0.38 mJy in a low-resolution radio image made with beam FWHM of 50 arcseconds. Radio source counts in the flux density range 0.4-8.7 mJy are estimated, with corrections applied for noise bias, effective area correction, and resolution bias. The resolution bias is mitigated using low-resolution radio images, while effects of source confusion are removed by using high-resolution images for identifying blended sources. Below 1 mJy the ATLBS counts are systematically lower than the previous estimates. Showing no evidence for an upturn down to 0.4 mJy, they do not require any changes in the radio source population down to the limit of the survey. The work suggests that automated image analysis for counts may be dependent on the ability of the imaging to reproduce connecting emission with low surface brightness and on the ability of the algorithm to recognize sources, which may require that source finding algorithms effectively work with multi-resolution and multi-wavelength data. The work underscores the importance of using source lists - as opposed to component lists - and correcting for the noise bias in order to precisely estimate counts close to the image noise and determine the upturn at sub-mJy flux density. This table was created by the HEASARC in April 2013 based on an electronic version of Table 2 from the reference paper that was obtained from the ApJ web site.. This is a service provided by NASA HEASARC .
AKARI NEP WSRT 20-cm Source Catalog
공공데이터포털
The Westerbork Radio Synthesis Telescope (WSRT) has been used in 2004 to make a deep radio survey of an ~1.7 degree2 field coinciding with the AKARI north ecliptic pole (NEP) deep field. The WSRT survey consisted of 10 pointings, mosaiced with enough overlap to maintain a similar sensitivity across the central region that reached as low as 21 microJanskies/beam (µJy/beam) at 1.4 GHz. The observations, data reduction and source count analysis are presented in the reference paper, along with a description of the overall scientific objectives. A catalog containing 462 sources detected with a resolution of 17.0 arcsecs by 15.5 arcsecs is presented. The differential source counts calculated from the WSRT data have been compared with those from the shallow VLA-NEP survey of Kollgaard et al. (1994, ApJS, 93, 145), and show a pronounced excess for sources fainter than ~1 mJy, consistent with the presence of a population of star-forming galaxies at sub-mJy flux levels. The AKARI NEP deep field is the focus of a major observing campaign conducted across the entire spectral region. The combination of these data sets, along with the deep nature of the radio observations will allow unique studies of a large range of topics including the redshift evolution of the luminosity function of radio sources, the clustering environment of radio galaxies, the nature of obscured radio-loud active galactic nuclei, and the radio/far-infrared correlation for distant galaxies. This catalog provides the basic data set for a future series of paper dealing with source identifications, morphologies, and the associated properties of the identified radio sources. This table was created by the HEASARC in March 2011 based on CDS catalog J/A+A/517/A54 file table2.dat. This is a service provided by NASA HEASARC .
Australia Telescope Hubble Deep Field-South Combined Source Catalog
공공데이터포털
Deep radio observations of a wide region centered on the Hubble Deep Field-South (HDF-S) have been performed, providing one of the most sensitive sets of radio observations acquired on the Australia Telescope Compact Array (ATCA) to date. A central rms of ~ 10 µJy is reached at four frequencies (1.4, 2.5, 5.2, and 8.7 GHz). In this table, the combined 4-frequency AT-HDFS Catalog including fluxes and spectral indices for sources detected at 1.4, 2.5, 5.2, and/or 8.7 GHz observations is presented to complement the single-frequency radio data for the 1.4 GHz observations which were presented in Paper II (Huynh et al., 2005, AJ, 130, 1373, available at the HEASARC as the ATHDFS1P4G table) in this series, and for the 2.5, 5.2, and/or 8.7 GHz observations which were presented in the reference paper (Paper III, Huynh et al., 2007, AJ, 133, 1331, available at the HEASARC as the ATHDFS3FRQ table). The details of the observations and data reduction are discussed in detail in Paper I of this series (Norris et al., 2005, AJ, 130, 1358) and summarized in Table 1 of the reference paper. The radio observations were carried out by the ATCA over 4 years from 1998 to 2001. The observations at 1.4 and 2.5 GHz consist of single pointings centered on RA (J2000.0) = 22h 33m 25.96s, Dec (J2000.0) = -60o 38' 09.0". The observations at 5.2 and 8.7 GHz consist of single pointings centered on RA (J2000.0) = 22h 32m 56.22s, Dec (J2000.0) = -60o 33' 02.7". The 5.2 and 8.7 GHz observations are centered on the HST WFPC field, while the 1.4 and 2.5 GHz observations were pointed halfway between the WFPC field and a bright confusing source to allow the bright source to be well cleaned from the 1.4 and 2.5 GHz images. This HEASARC table contains the final consolidated catalog of 473 individual sources and gives the flux densities at all frequencies for each individual radio source. It contains the 466 1.4-GHz sources from Paper II together with 5 unmatched 2.5-GHz sources and 2 unmatched 8.7-GHz sources. The procedure that the authors used to construct this catalog is discussed in Section 6 of the reference paper. This table was created by the HEASARC in December 2012 based on the CDS Catalog J/AJ/130/1371 file table9.dat which contains the entire contents of Table 9 from the published paper. This is a service provided by NASA HEASARC .
Giant Metrewave Radio Telescope 1h XMM/Chandra Survey Fld 610-MHz Source Catalog
공공데이터포털
This table contains the results of a deep 610-MHz survey of the 1hr XMM-Newton/Chandra survey area with the Giant Metre-wave Radio Telescope (GMRT). The resulting maps have a resolution of ~7 arcseconds and an rms noise limit of 60 µJy (µJy). To a 5-sigma detection limit of 300 uJy, the authors detect 223 sources within a survey area of 64 arcminutes in diameter. They compute the 610-MHz source counts and compare them to those measured at other radio wavelengths. The well-known flattening of the Eucidean-normalized 1.4-GHz source counts below ~ 2 mJy, usually explained by a population of starburst galaxies undergoing luminosity evolution, is seen at 610 MHz. In 2004 August, the 1hr field (centered at (J2000.0) RA, Dec = 01h 45m 27s, -04o 34' 42") was observed for approximately 4.5 hours at 610 MHz with the GMRT. Observations were carried out in dual band, spectral line mode, the former to maximize bandwidth and the latter to minimize chromatic aberration. Two sidebands, each of 128 spectral channels of 125 kHz, were centred on 602 and 618 MHz to give a total of 32 MHz bandwidth, with two independent circular polarizations recorded. Sources were extracted with the AIPS task SAD. A conservative peak flux density detection limit of 5 sigma (i.e. 300 uJy) was used to minimize the number of noise spikes spuriously detected as sources. In the areas surrounding the five brightest sources, detection was performed separately with higher detection thresholds to account for the higher rms noise. Within the 20% power radius of the GMRT primary beam at 610 MHz (32 arcminutes), 213 sources were discovered above a 5-sigma peak flux density detection limit of 300 uJy. In order to determine the success of the SAD source extraction, both the science images and the residual noise maps were carefully inspected. There were eight extended sources where the Gaussian model fit by SAD inadequately described the data: these are marked by source_flag = 'a' in this table. The characteristics of these sources were determined using the AIPS task TVSTAT, and contour plots of them are shown in Fig. 1 of the reference paper. Five of these appear to contain two peaks joined by extended emission, that is, they are double-lobe sources. This table was created by the HEASARC in June 2012 based on CDS Catalog J/MNRAS/378/995 file table1.dat. This is a service provided by NASA HEASARC .
VLA 74-MHz Deep High-Resolution Survey Source Catalog
공공데이터포털
This table contains some of the results from a 74-MHz survey of a 165 deg2 region located near the North Galactic Pole (NGP). This survey has an unprecedented combination of both spatial resolution (25" FWHM) and sensitivity (1-sigma as low as 24mJy/beam). The authors detect 949 sources at the 5-sigma level in this region, enough to begin exploring the nature of the 74-MHz source population. In their paper, they present differential source counts, spectral index measurements, and the size distribution as determined from counterparts in the high-resolution FIRST 1.4-GHz survey. They find a trend of steeper spectral indices for the brighter sources. Further, there is a clear correlation between spectral index and median source size, with the flat-spectrum sources being much smaller on average. Ultra-steep spectrum objects (power-law index alpha <= -1.2, where S_nu ~ nualpha) are identified. These sources are excellent candidates for high-redshift radio galaxies. The data used to produce this survey come from observations taken on 1998 March 7 intended to map two normal galaxies at 74 MHz (NGC 4565 and NGC 4631). These two pointings were separated by 6.4 degrees, roughly the radius of the primary beam at 74 MHz, allowing them to be ideally combined to produce a single deep image roughly 17 x 10 degrees in size. The combination of VLA A-configuration resolution (25 arcsec), favorable ionospheric conditions, and pointings in directions near the NGP, where the background temperature is low, produced the deepest observation ever obtained below 100 MHz. The same algorithm that was used in the 1.4-GHz NVSS was used to identify and characterize sources in this 74-MHz survey. The source detection algorithm had a threshold such that sources must have both a peak and integrated flux density level of at least 5 times the local rms noise level. Since the rms noise level varied from 24 mJy/beam to 80 mJy mJy/beam at the chosen field edge, the absolute level of the source-detection threshold of 5-sigma likewise varied over the image. This table was created by the HEASARC in August 2010 based on CDS catalog J/ApJS/150/417/ file table2.dat. This is a service provided by NASA HEASARC .
Australia Telescope Hubble Deep Field-South 2.5, 5.2 and 8.7-GHz Source Catalog
공공데이터포털
Deep radio observations of a wide region centered on the Hubble Deep Field-South (HDF-S) have been performed, providing one of the most sensitive sets of radio observations acquired on the Australia Telescope Compact Array (ATCA) to date. A central rms of ~ 10 µJy is reached at four frequencies (1.4, 2.5, 5.2, and 8.7 GHz). In this table, the full source catalogs from the 2.5, 5.2, and 8.7 GHz observations are presented to complement the data for the 1.4 GHz observations which were presented in Paper II (Huynh et al., 2005, AJ, 130, 1373, available at the HEASARC as the ATHDFS1P4G table) in this series, along with a detailed analysis of image quality and noise. The authors also have produced a consolidated catalog of all of their ATCA observations of the HDF-S by matching sources across all four of the frequencies in their survey (available at the HEASARC as the ATHDFSCCAT table). The details of the observations and data reduction are discussed in detail in Paper I of this series (Norris et al., 2005, AJ, 130, 1358) and summarized in Table 1 of the reference paper. The observations consist of single pointings centered on RA (J2000.0) = 22h 33m 25.96s, Dec (J2000.0) = -60o 38' 09.0" (2.5 GHz), and RA (J2000.0) = 22h 32m 56.22s, Dec (J2000.0) = -60o 33' 02.7" (5.2 and 8.7 GHz). The 5.2 and 8.7 GHz observations are centered on the HST WFPC field, while the 2.5 GHz observations were pointed halfway between the WFPC field and a bright confusing source to allow the bright source to be well cleaned from the 2.5 GHz image. At 5 sigma, the 5.2 and 8.7 GHz catalogs have over 96% reliability. At 2.5 GHz, the authors have enough statistics to examine the 5 - 5.5 sigma sources, and find that these are only about 40% reliable. With a SNR greater than 5.5 sigma, the 2.5 GHz catalog would have about 99% reliability. The authors thus cut off the catalogs at 5.5, 5, and 5 sigma for 2.5, 5.2, and 8.7 GHz, respectively. The final catalogs have 71, 24, and 6 sources at 2.5, 5.2, and 8.7 GHz, respectively. Given a prior 1.4 GHz position, it may be feasible to push the detection limit lower than 5 sigma. The authors searched for low-SNR sources by matching 3 - 5 sigma sources that lie within 2 sigma positional uncertainty of a 1.4 GHz source. The positional uncertainty was determined by adding the average 1.4 GHz uncertainty (1.1") in quadrature with the positional uncertainty of a 3 sigma source. At 2.5 GHz the allowed positional offset is 3.8", and for 5.2 and 8.7 GHz it is 2.8". Thus, there are 71, 18, and 2 sources at 2.5, 5.2, and 8.7 GHz, respectively, which are low-SNR high-frequency counterparts to 1.4 GHz sources. The authors included these sources in supplementary catalogs. This HEASARC table contains all 101 primary sources detected at 2.5, 5.2, and 8.7 GHz, as well as the 91 supplementary sources described above (the latter are flagged by having source_flag values of 'S'), for a grand total of 192 radio sources. This table was created by the HEASARC in December 2012 based on the CDS Catalog J/AJ/130/1371 files table47.dat, table58.dat and table68.dat, which contain the entire contents of Tables 4, 5, 6, 7 and 8 from the published paper. This is a service provided by NASA HEASARC .
Giant Metrewave Radio Telescope XMM Large Scale Structure 610-MHz Source Catalog
공공데이터포털
The low-frequency radio survey of the XMM-Large Scale Structure (XMM-LSS) field centered at RA (J2000) = 2h24m00s, Dec (J2000) = -4009'47" aims to study the connection between the extragalactic radio source populations and their environment as traced by X-ray and optical emission. In their paper, the authors present new radio observations of the XMM-LSS field carried out using the Giant Meterwave Radio Telescope (GMRT) at 240 and 610 MHz. These observations complement the observations presented by Cohen at al. (2003, ApJ, 591, 640; CDS Cat. ) and Tasse et al. (2006, A&A, 456, 791; CDS Cat. ) at 74 and 325 MHz with the Very Large Array (VLA). At 240 and 610 MHz, the authors reach noise levels of ~2.5 and ~0.3 mJy/beam, leading to the detection of 466 and 769 sources over 18.0 and 12.7 degree2 with resolutions of 14.7 arcseconds and 6.5 arcseconds, respectively. Combining these data with the available source lists at 74 MHz, 325 MHz (Tasse et al., 2006) and 1400MHz (NVSS), the authors built a multifrequency catalog containing 1611 radio sources. They checked for consistency of the astrometry and flux density estimates. They fit a simple synchrotron radiation model to the flux density measurements of the 318 radio sources that were detected in at least 4 bands. While ~26% of them showed signature of spectral ageing, ~6% showed self absorption. This table contains the GMRT 610-MHz source list, comprising 592 single sources and 445 components of multiple sources, for a total of 1037 entries. For the multiple sources, each component (A, B, etc.) is listed separately, in order of decreasing brightness. This table was created by the HEASARC in February 2012 based on CS Catalog J/A+A/471/1105 file table4.dat. This is a service provided by NASA HEASARC .
Molonglo Observatory Synthesis Telescope ATLAS 843-MHz Source Catalog
공공데이터포털
At the faintest radio flux densities (S1.4 < 10 mJy), conflicting results have arisen regarding whether there is a flattening of the average spectral index between a low radio frequency (325 or 610 MHz) and, for example, 1.4 GHz. The authors present a new catalog of 843-MHz radio sources in the European Large Area ISO Survey-South 1 (ELAIS-S1) field, which contains the sources, their Australia Telescope Large Area Survey (ATLAS) counterparts and the spectral index distribution of the sources as a function of flux density. The authors do not find any statistically significant evidence for a trend towards flatter spectral indices with decreasing flux density. In the reference paper, they investigate the spectral index distribution with redshift for those sources with reliable redshifts and explore the infrared properties. An initial sample of faint compact steep-spectrum sources in ATLAS are also presented, with a brief overview of their properties. To obtain low-radio-frequency (843-MHz) data within the ATLAS ELAIS-S1 region (Middelberg et al. 2008, AJ, 135, 1276, the tables from which are available as the ATLASESID and ATLASESCPT tables in the HEASARC database), the authors used the Molonglo Observatory Synthesis Telescope (MOST). They have made 31 separate 12-h observations taken with MOST, which were combined into a single image with a spatial resolution of 62 arcsec x 43 arcsec. This table was created by the HEASARC in January 2013 based on the CDS Catalog J/MNRAS/421/1644 file table1.dat. This is a service provided by NASA HEASARC .
Giant Metrewave Radio Telescope XMM Large Scale Structure 240-MHz Source Catalog
공공데이터포털
The low-frequency radio survey of the XMM-Large Scale Structure (XMM-LSS) field centered at RA (J2000) = 2h24m00s, Dec (J2000) = -4009'47" aims to study the connection between the extragalactic radio source populations and their environment as traced by X-ray and optical emission. In their paper, the authors present new radio observations of the XMM-LSS field carried out using the Giant Meterwave Radio Telescope (GMRT) at 240 and 610 MHz. These observations complement the observations presented by Cohen at al. (2003, ApJ, 591, 640; CDS Cat. ) and Tasse et al. (2006, A&A, 456, 791; CDS Cat. ) at 74 and 325 MHz with the Very Large Array (VLA). At 240 and 610 MHz, the authors reach noise levels of ~2.5 and ~0.3 mJy/beam, leading to the detection of 466 and 769 sources over 18.0 and 12.7 degree2 with resolutions of 14.7 arcseconds and 6.5 arcseconds, respectively. Combining these data with the available source lists at 74 MHz, 325 MHz (Tasse et al., 2006) and 1400MHz (NVSS), the authors built a multifrequency catalog containing 1611 radio sources. They checked for consistency of the astrometry and flux density estimates. They fit a simple synchrotron radiation model to the flux density measurements of the 318 radio sources that were detected in at least 4 bands. While ~26% of them showed signature of spectral ageing, ~6% showed self absorption. This table contains the GMRT 240-MHz source list, comprising 388 single sources and 183 components of multiple sources, for a total of 571 entries. For the multiple sources, each component (A, B, etc.) is listed separately, in order of decreasing brightness. This table was created by the HEASARC in February 2012 based on CS Catalog J/A+A/471/1105 file table3.dat. This is a service provided by NASA HEASARC .
Phoenix Deep Survey Optical and Near-Infrared Counterparts Catalog
공공데이터포털
Using a deep Australia Telescope Compact Array (ATCA) radio survey covering an area of ~3 deg2 to a 4-sigma sensitivity of >= 100 µJy (µJy) at 1.4 GHz, the authors study the nature of faint radio galaxies. The region, 2 degrees in diameter and centered on RA and Dec (J2000.0) of 1h 14m 12.16s, -45o 44' 08.0" (Galactic latitude of -71o), is known as the Phoenix Deep Field. About 50% of the detected radio sources are identified with an optical counterpart revealed by CCD photometry to mR = 22.5 magnitudes. Near-infrared (K-band) data are also available for a selected sample of the radio sources, while spectroscopic observations have been carried out for about 40% of the optically identified sample. These provide redshifts and information on the stellar content. Emission-line ratios imply that most of the emission-line sources are star-forming galaxies, with a small contribution (~ 10%) from Seyfert 1/Seyfert 2 type objects. The authors also find a significant number of absorption-line systems, likely to be ellipticals. These dominate at high flux densities ( > 1 mJy) but are also found at sub-mJy levels. Using the Balmer decrement, they find a visual extinction AV = 1.0 for the star-forming faint radio sources. This moderate reddening is consistent with the (V - R) and (R - K) colors of the optically identified sources. For emission-line galaxies, there is a correlation between the radio power and the H-alpha luminosity, in agreement with the result of Benn et al. (1993, MNRAS, 263, 98). This suggests that the radio emission of starburst radio galaxies is a good indicator of star formation activity. When calculating luminosities, the authors assume a cosmology with a Hubble constant H0 of 50 km s-1 Mpc-1 and a deceleration parameter q0 of 0.5. This table was created by the HEASARC in June 2013 based on an electronic version of Table 1 from the reference paper, which details the photometric (optical and near-infrared), radio, spectroscopic and intrinsic properties of the faint radio sources in the PDS with established redshifts, which was obtained from the CDS web site (their catalog J/MNRAS/306/708 file table1.dat). This is a service provided by NASA HEASARC .
목록