Capability Type: Simple Cone Search - STScI NAVO Directory Search Results

Start Over Capability Type Simple Cone Search

2591. Chandra Deep Field-South ATLAS 5.5GHz DR2

ID:: ivo://CDS.VizieR/J/MNRAS/454/952
Title:: Chandra Deep Field-South ATLAS 5.5GHz DR2
Short Name:: J/MNRAS/454/952
Date:: 21 Oct 2021
Publisher:: CDS
Description:: We present a new image of the 5.5GHz radio emission from the extended Chandra Deep Field South. Deep radio observations at 5.5GHz were obtained in 2010 and presented in the first data release. A further 76h of integration has since been obtained, nearly doubling the integration time. This paper presents a new analysis of all the data. The new image reaches 8.6{mu}Jy rms, an improvement of about 40% in sensitivity. We present a new catalogue of 5.5GHz sources, identifying 212 source components, roughly 50% more than were detected in the first data release. Source counts derived from this sample are consistent with those reported in the literature for S_5.5GHz_>0.1mJy but significantly lower than published values in the lowest flux density bins (S_5.5GHz_<0.1mJy), where we have more detected sources and improved statistical reliability. The 5.5GHz radio sources were matched to 1.4GHz sources in the literature and we find a mean spectral index of -0.35+/-0.10 for S_5.5GHz_>0.5mJy, consistent with the flattening of the spectral index observed in 5GHz sub-mJy samples. The median spectral index of the whole sample is {alpha}_med_=-0.58, indicating that these observations may be starting to probe the star-forming population. However, even at the faintest levels (0.05<S_5.5GHz_<0.1mJy), 39% of the 5.5GHz sources have flat or inverted radio spectra. Four flux density measurements from our data, across the full 4.5-6.5GHz bandwidth, are combined with those from literature and we find 10% of sources (S_5.5GHz_>~0.1mJy) show significant curvature in their radio spectral energy distribution spanning 1.4-9GHz.

2592. Chandra Deep Field South 4-Megasecond Catalog

ID:: ivo://nasa.heasarc/chandfs4ms
Title:: Chandra Deep Field South 4-Megasecond Catalog
Short Name:: CHANDFS4MS
Date:: 28 Feb 2025
Publisher:: NASA/GSFC HEASARC
Description:: This table contains the main Chandra source catalog for the 4 megasecond (Ms) Chandra Deep Field-South (CDF-S), which is the deepest Chandra survey to date and covers an area of 464.5 arcmin2. It contains 740 X-ray sources that are detected with wavdetect at a false-positive probability threshold of 10-5 in at least one of three X-ray bands (0.5-8 keV, full band; 0.5-2 keV, soft band; and 2-8 keV, hard band) and also satisfy a binomial-probability source-selection criterion of P < 0.004 (i.e., the probability of sources not being real is less than 0.004); this approach is designed to maximize the number of reliable sources detected. A total of 300 main-catalog sources are new compared to the previous 2 Ms CDF-S main-catalog (the HEASARC CHANDFS2MS table) sources. The authors determined X-ray source positions using centroid and matched-filter techniques and obtained a median positional uncertainty of ~0.42 arcseconds. In their paper, they also provided a supplementary catalog (not included in this HEASARC table), which consists of 36 sources that are detected with wavdetect at a false-positive probability threshold of 10-5, satisfy the condition of 0.004 < P < 0.1, and have an optical counterpart with R < 24. Multiwavelength identifications, basic optical/infrared/radio photometry, and spectroscopic/photometric redshifts are provided for the X-ray sources in the main and supplementary catalogs. Seven hundred sixteen (~97%) of the 740 main-catalog sources have multiwavelength counterparts, with 673 (~94% of 716) having either spectroscopic or photometric redshifts. The 740 main-catalog sources span broad ranges of full-band flux and 0.5-8 keV luminosity; the 300 new main-catalog sources span similar ranges although they tend to be systematically lower. Basic analyses of the X-ray and multiwavelength properties of the sources indicate that >75% of the main-catalog sources are active galactic nuclei (AGNs); of the 300 new main-catalog sources, about 35% are likely normal and starburst galaxies, reflecting the rise of normal and starburst galaxies at the very faint flux levels uniquely accessible to the 4 Ms CDF-S. Near the center of the 4 Ms CDF-S (i.e., within an off-axis angle of 3'), the observed AGN and galaxy source densities have reached 9800 (+1300,-1100) deg-2 and 6900 (+1100,-900) deg-2, respectively. Simulations show that the main catalog is highly reliable and is reasonably complete. The mean backgrounds (corrected for vignetting and exposure-time variations) are 0.063 and 0.178 counts Ms-1 pixel-1 (for a pixel size of 0.492 arcseconds) for the soft and hard bands, respectively; the majority of the pixels have zero background counts. The 4 Ms CDF-S reaches on-axis flux limits of ~3.2 x 10-17, 9.1 x 10-18, and 5.5 x 10-17 erg cm-2 s-1 for the full, soft, and hard bands, respectively. An increase in the CDF-S exposure time by a factor of ~2-2.5 would provide further significant gains and probe key unexplored discovery space. This HEASARC table comprises Table 3 from the reference paper, the Main Chandra Source Catalog of 740 X-ray sources. The 36 optically bright Chandra sources that were listed in Table 6 of the reference paper are thus not included herein. This table was created by the HEASARC in July 2011 based on an electronic version of Table 3 from the reference paper which was obtained from the ApJS web site. This is a service provided by NASA HEASARC .

2593. Chandra Deep Field South 1-Megasecond Catalog

ID:: ivo://nasa.heasarc/chandfs1ms
Title:: Chandra Deep Field South 1-Megasecond Catalog
Short Name:: CDFS1MS
Date:: 28 Feb 2025
Publisher:: NASA/GSFC HEASARC
Description:: The Chandra Deep Field South (CDFS) 1-Megasecond Catalog is the source catalog obtained from a 942 kilosecond exposure, using the Advanced CCD Imaging Spectrometer (ACIS-I) on the Chandra X-ray Observatory. Eleven individual pointings made between 1999 October and 2000 December were combined to generate the final image used for object detection. Catalog generation proceeded simultaneously using two different methods: a method of the authors' own design using a modified version of the SExtractor algorithm, and a wavelet transform technique developed specifically for Chandra observations. The detection threshold was set in order to have less than 10 spurious sources, as assessed by extensive simulations. The catalog as published was subdivided into four sections: the primary list consisting of objects common to the two detection methods, two secondary lists containing sources which were detected by either the SExtractor algorithm alone or by the wavelet technique alone, and the fourth list consisting of possible diffuse or extended sources. The flux limits at the aimpoint for the soft (0.5 - 2 keV) and hard (2 - 10 keV) bands are 5.5 x 10-17 erg/s/cm2 and 4.5 x 10-16 erg/s/cm2, respectively. The total number of sources is 346; out of them, 307 were detected in the 0.5 - 2 keV band, and 251 in the 2 - 10 keV band. Optical identifications are also presented for the catalogued sources. The primary optical data are R band imaging from VLT/FORS1 to a depth of R ~ 26.5 (Vega). In regions of the field not covered by the VLT/FORS1 deep imaging, the authors use R-band data obtained with the Wide Field Imager (WFI) on the ESO-MPI 2.2 m telescope, as part of the ESO Imaging Survey (EIS), which cover the entire X-ray survey. The FORS1/Chandra offsets are small, ~1 arcsecond. Coordinate cross-correlation finds 85% of the Chandra sources covered by FORS1 R to have counterparts within the 3-sigma error box (>~1.5 arcseconds, depending on off-axis angle and X-ray signal-to-noise). The unidentified fraction of sources, approximately 10% - 15%, is close to the limit expected from the observed X-ray flux to R-band ratio distribution for the identified sample. This online catalog was created by the HEASARC in June 2002 based on machine-readable versions of 2, 3 and 4 of Giacconi et al. (2002) that were obtained from the CDS. This is a service provided by NASA HEASARC .

2594. Chandra Deep Field South 2-Megasecond Catalog

ID:: ivo://nasa.heasarc/chandfs2ms
Title:: Chandra Deep Field South 2-Megasecond Catalog
Short Name:: CHANDFS2MS
Date:: 28 Feb 2025
Publisher:: NASA/GSFC HEASARC
Description:: This table contains point-source catalogs for the ~2 Ms exposure of the Chandra Deep Field-South (CDF-S) this is one of the two most sensitive X-ray surveys ever performed. The survey covers an area of ~436 arcmin2 and reaches on-axis sensitivity limits of ~1.9 x 10-17 and ~1.3 x 10-16 erg cm-2 s-1 for the 0.5-2.0 and 2-8 keV bands, respectively. Four hundred and sixty-two X-ray point sources (source_sample = 'Main CDF-S' in this table) are detected in at least one of three X-ray bands that were searched; 135 of these sources are new compared to the previous ~1 Ms CDF-S detections. Source positions are determined using centroid and matched-filter techniques; the median positional uncertainty is ~0.36". The X-ray-to-optical flux ratios of the newly detected sources indicate a variety of source types; ~55% of them appear to be active galactic nuclei, while ~45% appear to be starburst and normal galaxies. This table contains, in addition to the main Chandra catalog, the supplementary catalog of 86 X-ray sources (source_sample = 'CDF-S + E-CDF-S' in this table) in the ~2 Ms CDF-S footprint that was created by merging the ~250 ks Extended Chandra Deep Field-South with the CDF-S; this approach provides additional sensitivity in the outer portions of the CDF-S. This table also contains a second supplementary catalog (source_sample = 'Optically Bright' in this table) of 30 X-ray sources which was constructed by matching lower significance X-ray sources to bright optical counterparts (R < 23.8); the majority of these sources appear to be starburst and normal galaxies. The total number of sources in this table, which contains the main and 2 supplementary catalogs, is thus 578. Optical R-band counterparts and basic optical and infrared photometry are provided for the X-ray sources in the main and supplementary catalogs. The authors also include existing spectroscopic redshifts for 224 of the X-ray sources. The average backgrounds in the 0.5-2.0 and 2-8 keV bands are 0.066 and 0.167 counts Ms-1 pixel-1, respectively, and the background counts follow Poisson distributions. The effective exposure times and sensitivity limits of the CDF-S are now comparable to those of the ~2 Ms Chandra Deep Field-North (CDF-N). In their paper, the authors also present cumulative number counts for the main catalog and compare the results to those for the CDF-N. The soft-band number counts for these two fields agree well with each other at fluxes higher than ~2 x 10-16 erg cm-2 s-1, while the CDF-S number counts are up to ~25% smaller than those for the CDF-N at fluxes below ~2 x 10-16 erg cm-2 s-1 in the soft band and ~2 x 10-15 erg cm-2 s-1 in the hard band, suggesting small field-to-field variations. This table was created by the HEASARC in December 2008 based on the electronic version of Tables 2, 5 and 6 from the reference paper which were obtained from the ApJ web site. It was last modified by the HEASARC in July 2011. This is a service provided by NASA HEASARC .

2595. Chandra Deep Field-South 7-Megasecond X-Ray Source Catalog

ID:: ivo://nasa.heasarc/chandfs7ms
Title:: Chandra Deep Field-South 7-Megasecond X-Ray Source Catalog
Short Name:: CHANDFS7MS
Date:: 28 Feb 2025
Publisher:: NASA/GSFC HEASARC
Description:: This table contains the X-ray source catalogs for the ~7 Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2 square arcminutes. Utilizing WAVDETECT for initial source detection and ACIS Extract for photometric extraction and significance assessment, the authors have created a main source catalog (entries with source_sample = 'M' in this HEASARC table) containing 1,008 sources that are detected in up to three X-ray bands: 0.5-7.0 keV, 0.5-2.0 keV, and 2-7 keV. A supplementary source catalog entries with source_sample = 'S' in this HEASARC table) is also provided, including 47 lower-significance sources that have bright (Ks <~ 23m) near-infrared (NIR) counterparts. The authors have identified multiwavelength counterparts for 992 (98.4%) of the 1,008 main-catalog sources, and they have collected redshifts for 986 of these sources, including 653 spectroscopic redshifts and 333 photometric redshifts. Based on the X-ray and multiwavelength properties, the authors have identified 711 active galactic nuclei (AGNs) from the main-catalog sources. Compared to the previous ~4 Ms CDF-S catalogs, 291 of the main-catalog sources are new detections. The observations utilized in this survey have achieved unprecedented X-ray sensitivity with average flux limits over the central ~1 arcmin2 region of ~1.9 x 10-17, 6.4 x 10-18, and 2.7 x 10-17 erg cm-2 s-1 in the three X-ray bands, respectively. In the reference paper, the authors provide cumulative number-count measurements observing, for the first time, that normal galaxies start to dominate the X-ray source population at the faintest 0.5-2.0 keV flux levels. The highest X-ray source density reaches ~50,500 deg-2, and 47% +/- 4% of these sources are AGNs (~23,900 deg-2). The authors adopted a binomial no-source probability value, PB < 0.007 as the criterion to prune their initial candidate source list and generate a main source catalog, which includes 1,008 sources with a ~97% multiwavelength-identification rate. This adopted PB threshold will have inevitably rejected real X-ray sources. To recover some of these real sources, the authors created a supplementary source catalog that contains lower-significance X-ray sources that have bright optical/NIR counterparts; the chance of a bright optical/NIR source being associated with a spurious X-ray detection is quite small. A total of 47 candidate CDF-S sources having 0.007 <= PB < 0.1 are associated with bright, Ks <= 23m, TENIS sources, where the false-match rate is only 1.7%, and these 47 sources constitute the supplementary catalog. A Galactic column density of NH,Gal = 8.8 * 1019 cm-2 along the line of sight to the CDF-S is assumed in this study. All quoted magnitudes are in the AB system. A cosmology with H0 = 67.8 km s-1 Mpc-1, OmegaM = 0.308, and OmegaLambda = 0.692 (Planck Collaboration et al. 2016 values) is used to calculate luminosities. This HEASARC table contains the 1,008 sources from the main Chandra source catalog (these entries are identified by the HEASARC-created source_sample parameter being set to 'M' in this table) and the 47 lower-significance sources from the supplementary NIR-bright Chandra source catalog (these entries are identified by the HEASARC-created source_sample parameter being set to 'S' in this table). This table thus has 1,055 entries. This table was created by the HEASARC in March 2017 based upon electronic versions of Tables 4 and 5, the 'Main Chandra Source Catalog' and the 'Supplementary NIR-Bright Chandra Source Catalog', respectively, which were obtained from the ApJS website. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .

2596. Chandra Deep Field South. 1 Ms catalog

ID:: ivo://CDS.VizieR/J/ApJS/139/369
Title:: Chandra Deep Field South. 1 Ms catalog
Short Name:: J/ApJS/139/369
Date:: 21 Oct 2021
Publisher:: CDS
Description:: In this paper we present the source catalog obtained from a 942ks exposure of the Chandra Deep Field South (CDFS), using the Advanced CCD Imaging Spectrometer (ACIS-I) on the Chandra X-ray Observatory. Eleven individual pointings made between 1999 October and 2000 December were combined to generate the final image used for object detection. Catalog generation proceeded simultaneously using two different methods: a method of our own design using a modified version of the SExtractor algorithm, and a wavelet transform technique developed specifically for Chandra observations. The detection threshold has been set in order to have less than 10 spurious sources, as assessed by extensive simulations. We subdivided the catalog into four sections: the primary list consisting of objects common to the two detection methods, two secondary lists containing sources which were detected by (1) the SExtractor algorithm alone and (2) the wavelet technique alone, and the fourth list consisting of possible diffuse or extended sources. The flux limits at the aimpoint for the soft (0.5-2keV) and hard (2-10keV) bands are 5.5x10^-17^erg/s/cm^2^ and 4.5x10^-16^erg/s/cm^2^, respectively. The total number of sources is 346; out of them, 307 were detected in the 0.5-2keV band, and 251 in the 2-10keV band. We also present optical identifications for the catalogued sources. Our primary optical data are R band imaging from VLT/FORS1 to a depth of R~26.5 (Vega). In regions of the field not covered by the VLT/FORS1 deep imaging, we use R-band data obtained with the Wide Field Imager (WFI) on the ESO-MPI 2.2 m telescope, as part of the ESO Imaging Survey (EIS), which cover the entire X-ray survey. We found that the FORS1/Chandra offsets are small, ~1". Coordinate cross-correlation finds 85% of the Chandra sources covered by FORS1 R to have counterparts within the 3{sigma} error box (>~1.5" depending on off-axis angle and X-ray signal-to-noise). The unidentified fraction of sources, approximately ~10%-15%, is close to the limit expected from the observed X-ray flux to R-band ratio distribution for the identified sample.

2597. Chandra Deep Field South: multi-colour data

ID:: ivo://CDS.VizieR/II/253A
Title:: Chandra Deep Field South: multi-colour data
Short Name:: II/253A
Date:: 21 Oct 2021
Publisher:: CDS
Description:: Table 3 contains the object catalogue of the COMBO-17 CDFS field. The observations were carried out with the Wide Field Imager (WFI) at the MPG/ESO 2.2-m telescope on La Silla, Chile, between October 1999 and January 2001 in four independent observing runs. The field measures 31.5'x30', is centered on RA=03:32:25, DE=-27:48:50 and contains the Chandra Deep Field South. The table contains 63501 objects found on the deep R-band image cdfs_r.fit by SExtractor with S/N>3. The 5-{sigma} magnitude limit for point sources is Rmag=26.0. Morphological information from the SExtractor measurement is included. Multiple observations in different observing runs of six different filters allow the identification of variable objects. The table contains positions, flags and flux measurements in UBVRI and 12 optical medium-band filters. In addition, we include multi-colour classification, photometric redshifts, luminosity distances and a number of absolute restframe magnitudes in different filters (Johnson, Sloan, Bessell). cdfs_u.fit, cdfs_b.fit, cdfs_v.fit, cdfs_r.fit and cdfs_i.fit are coadded sumframes in UBVRI of the CDFS field. These sumframes are stacked from flat-fielded and cosmic-corrected individual images by applying only full pixel shifts. Therefore, the coordinate frames differ slightly between the images. The coordinates in Table 3 refer to image cdfs_r.fit. The images in BVRI are obtained from observations carried out in observing run D (Oct 1999, see also Note (11) in the byte-by-byte description of table3.dat) while the U-band image is obtained from observing run G (Jan 2001). The exposure times are 14400s (U), 5000s (B), 8400s (V), 15000s (R) and 7550s (I). The intensity levels are given in units of photons hitting the detector (already corrected for the gain of the CCD). The data included here supersede the table2.dat of the COMBO-17 published in 2001 (J/A+A/377/442)

2598. Chandra Deep Field-South: Optical spectroscopy

ID:: ivo://CDS.VizieR/J/ApJS/155/271
Title:: Chandra Deep Field-South: Optical spectroscopy
Short Name:: J/ApJS/155/271
Date:: 21 Oct 2021
Publisher:: CDS
Description:: We present the results of our spectroscopic follow-up program of the X-ray sources detected in the 942ks exposure of the Chandra Deep Field-South (CDFS). A total of 288 possible counterparts were observed at the VLT with the FORS1/FORS2 spectrographs for 251 of the 349 Chandra sources (including three additional faint X-ray sources). Spectra and R-band images are shown for all the observed sources and R-K colors are given for most of them. Spectroscopic redshifts were obtained for 168 X-ray sources, of which 137 have both reliable optical identification and redshift estimate (including 16 external identifications). The R<24 observed sample comprises 161 X-ray objects (181 optical counterparts), and 126 of them have unambiguous spectroscopic identification.

2599. Chandra Deep Field South: R-band photometry

ID:: ivo://CDS.VizieR/J/A+A/377/442
Title:: Chandra Deep Field South: R-band photometry
Short Name:: J/A+A/377/442
Date:: 21 Oct 2021
Publisher:: CDS
Description:: Table2 is based on an object list that was created by applying SExtractor software to an R-band image coadded from 36 frames with 15070s total exposure time taken in October 1999 using the Wide Field Imager at the MPG/ESO 2.2-m telescope on La Silla, Chile. The field measures 31.5'x30', is centered on 03:32:25-27:48:50 and contains the Chandra Deep Field South. The average PSF is on the order of 0.75". The catalog contains 63501 objects found by SExtractor with S/N>3. It has not been cleaned for spurious detection of false objects arising from scattered light or diffraction spikes of extremely bright stars. Using this object list aperture magnitudes 'Bmag', 'Vmag' and 'Rmag' were measured on B-, V- and R-band images taken in October 1999. These are listed with its errors. Additionally an aperture magnitude 'R2mag' with its error is included that is taken from R-band imaging from February 2000 with an exposure time of 8440s taken in 21 frames, yielding a total exposure time in the R-band of 23510s=6.5h. The 10-sigma magnitude limits for point sources are Bmag=24.9, Vmag=24.6, Rmag=25.1 and R2mag=24.8. The aperture magnitudes were calculated by counting the flux in an aperture with a Gaussian weighting function of 1.3" width. The flux is scaled to the total flux expected for stars.

2600. Chandra Deep Field-South survey: 7Ms sources

ID:: ivo://CDS.VizieR/J/ApJS/228/2
Title:: Chandra Deep Field-South survey: 7Ms sources
Short Name:: J/ApJS/228/2
Date:: 21 Oct 2021
Publisher:: CDS
Description:: We present X-ray source catalogs for the ~7Ms exposure of the Chandra Deep Field-South (CDF-S), which covers a total area of 484.2arcmin^2^. Utilizing wavdetect for initial source detection and ACIS Extract for photometric extraction and significance assessment, we create a main source catalog containing 1008 sources that are detected in up to three X-ray bands: 0.5-7.0keV, 0.5-2.0keV, and 2-7keV. A supplementary source catalog is also provided, including 47 lower-significance sources that have bright (K_s_<=23) near-infrared counterparts. We identify multiwavelength counterparts for 992 (98.4%) of the main-catalog sources, and we collect redshifts for 986 of these sources, including 653 spectroscopic redshifts and 333 photometric redshifts. Based on the X-ray and multiwavelength properties, we identify 711 active galactic nuclei (AGNs) from the main-catalog sources. Compared to the previous ~4Ms CDF-S catalogs, 291 of the main-catalog sources are new detections. We have achieved unprecedented X-ray sensitivity with average flux limits over the central ~1arcmin^2^ region of ~1.9x10^-17^, 6.4x10^-18^, and 2.7x10^-17^erg/cm^2^/s in the three X-ray bands, respectively. We provide cumulative number-count measurements observing, for the first time, that normal galaxies start to dominate the X-ray source population at the faintest 0.5-2.0keV flux levels. The highest X-ray source density reaches ~50500deg^-2^, and 47%+/-4% of these sources are AGNs (~23900deg^-2^).

« Previous
Next »
1
2
…
256
257
258
259
260
261
262
263
264
…
1,808
1,809

Search

Search Constraints

Search Results

2591. Chandra Deep Field-South ATLAS 5.5GHz DR2

2592. Chandra Deep Field South 4-Megasecond Catalog

2593. Chandra Deep Field South 1-Megasecond Catalog

2594. Chandra Deep Field South 2-Megasecond Catalog

2595. Chandra Deep Field-South 7-Megasecond X-Ray Source Catalog

2596. Chandra Deep Field South. 1 Ms catalog

2597. Chandra Deep Field South: multi-colour data

2598. Chandra Deep Field-South: Optical spectroscopy

2599. Chandra Deep Field South: R-band photometry

2600. Chandra Deep Field-South survey: 7Ms sources

Limit your search

Subject

Publisher

Resource Type

Content Level

Instrument

Facility

Validation Level

Rights

Capability Type

Result Type