- ID:
- ivo://nasa.heasarc/ecdfscxo
- Title:
- Extended Chandra Deep Field-South X-Ray Point Source Catalog
- Short Name:
- ECDFSCXO
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Extended Chandra Deep Field-South (ECDFS) survey consists of four Chandra X-Ray Observatory (CXO) ACIS-I pointings and covers ~1100 arcmin<sup>2</sup> (~0.3 deg<sup>2</sup>) centered on the original CDF-S field to a depth of approximately 228 ks. This is the largest Chandra survey ever conducted at such depth, and only one XMM-Newton survey reaches a lower flux limit in the hard 2.0-8.0 keV band. The authors detect 651 unique sources: 587 using a conservative source-detection threshold (identified by source_type = 'P' for primary source) and 64 (identified by source_type = 'S' for secondary source) using a lower source-detection threshold. These are combined in this HEASARC representation but were presented as two separate catalogs (Table 4 contained the primary sources, and Table 5 the secondary sources) in the original reference paper. Of the 651 total sources, 561 are detected in the full 0.5-8.0 keV band, 529 in the soft 0.5-2.0 keV band, and 335 in the hard 2.0-8.0 keV band. For point sources near the aim point, the limiting fluxes are approximately 1.7 x 10<sup>-16</sup> and 3.9 x 10<sup>-16</sup> ergs/cm<sup>2</sup>/s in the 0.5-2.0 and 2.0-8.0 keV bands, respectively. In their paper, the authors present the differential and cumulative flux distributions, which are in good agreement with the number counts from previous deep X-ray surveys and with the predictions from an active galactic nucleus (AGN) population synthesis model that can explain the X-ray background. In general, fainter sources have harder X-ray spectra, consistent with the hypothesis that these sources are mainly obscured AGNs. All nine observations of the ECDFS survey field were conducted with the Advanced CCD Imaging Spectrometer (ACIS) on board Chandra as part of the approved guest observer program in Cycle 5. Notice that Lehmer et al. (2005, ApJS, 161, 21) conducted a somewhat different analysis on these same data and obtained similar, but not identical results, e.g., Lehmer et al. found 809 total X-ray sources compared to 651 in the present table. This table was created by the HEASARC in April 2009 based on the electronic versions of Tables 4 and 5 from the paper which were obtained from the CDS (their catalog J/AJ/131/2373 files table4.dat and table5.dat). This is a service provided by NASA HEASARC .
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/549/A51
- Title:
- Extended CO structures in NGC6240
- Short Name:
- J/A+A/549/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep CO(1-0) observations of NGC6240 performed with the IRAM Plateau de Bure Interferometer (PdBI). NGC6240 is the prototypical example of a major galaxy merger in progress, caught at an early stage, with an extended, strongly-disturbed butterfly- like morphology and a heavily obscured active nucleus in the core of each progenitor galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/453/155
- Title:
- Extended envelopes around Galactic Cepheids II.
- Short Name:
- J/A+A/453/155
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of long-baseline interferometric observations of the classical Cepheids Polaris and delta Cep in the near infrared K' band (1.9-2.3 microns), using the FLUOR instrument of the CHARA Array. Following our previous detection of a circumstellar envelope (CSE) around L Car (Kervella et al., 2006A&A...448..623K), we report similar detections around Polaris and delta Cep. Owing to the large data set acquired on Polaris, in both the first and second lobes of visibility function, we have detected the presence of a circum-stellar envelope (CSE), located at 2.4+/-0.1 stellar radii, accounting for 1.5+/-0.4% of the stellar flux in the K' band. A similar model is applied to the delta Cep data, which shows improved agreement compared to a model without CSE. Finally, we find that the bias in estimating the angular diameter of delta Cep in the framework of the Baade-Wesselink method (Merand et al., 2005A&A...438L...9M) is of the order of 1% or less in the K' band. A complete study of the influence of the CSE is proposed in this context, showing that at the optimum baseline for angular diameter variation detection, the bias is of the order of the formal precision in the determination of the delta Cep pulsation amplitude (1.6%). Description: Individual interferometric squared visibility measurements. Data were acquired in the wide infrared K' band. We also provide informations about calibrator stars.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A59
- Title:
- Extended galaxy clusters from RXGCC
- Short Name:
- J/A+A/658/A59
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- There is a known tension between cosmological parameter constraints obtained from the primary cosmic microwave background (CMB) and those from galaxy cluster samples. One possible explanation for this discrepancy could be that the incompleteness of detected clusters is higher than estimated, and certain types of groups or clusters of galaxy have been missed in the past. We aim to search for galaxy groups and clusters with particularly extended surface brightness distributions, by creating a new X-ray selected catalog of extended galaxy clusters from the ROSAT All-Sky Survey (RASS), using a dedicated source detection and characterization algorithm optimized for extended sources. Our state-of-the-art algorithm includes multi-resolution filtering, source detection and characterization. Through extensive simulations, the detection efficiency and sample purity are investigated. Previous cluster catalogs in X-ray and other wave-bands, as well as spectroscopic and photometric redshifts of galaxies are used for the cluster identification. We report a catalog of galaxy clusters at high galactic latitude based on the ROSAT All-sky Survey, named as RASS-based extended X-ray Galaxy Cluster Catalog (RXGCC), which includes 944 groups and clusters. Out of this number, 641 clusters have been identified through intra-cluster medium (ICM) emission previously (Bronze), 154 known optical and infrared clusters are detected as X-ray clusters for the first time (Silver), and 149 identified as clusters for the first time (Gold). Based on 200 simulations, the contamination ratio of the detections which were identified as clusters by ICM emission, and the detections which were identified as optical and infrared clusters in previous work is 0.008 and 0.100, respectively. Compared with Bronze sample, the Gold+Silver sample is less luminous, less massive, and has a flatter surface brightness profile. Specifically, the median flux in [0.1-2.4]keV band for Gold + Silver and Bronze sample is 2.496x10^-12^erg/s/cm^2^ and 4.955x10^-12^erg/s/cm^2^, respectively. The median value of {beta} (the slope of cluster surface brightness profile) is 0.76 and 0.83 for Gold + Silver and Bronze sample, respectively. This whole sample is available at https://github.com/wwxu/rxgcc.github.io/blob/master/table_rxgcc.fits.
- ID:
- ivo://CDS.VizieR/J/MNRAS/449/3263
- Title:
- Extended galaxy halo gas through HI and OVI
- Short Name:
- J/MNRAS/449/3263
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of extended galaxy halo gas through HI and OVI absorption over two decades in projected distance at z~0.2. The study is based on a sample of 95 galaxies from a highly complete (>80 percent) survey of faint galaxies (L>0.1L*) with archival quasar absorption spectra and 53 galaxies from the literature. A clear anticorrelation is found between HI (OVI) column density and virial radius normalized projected distance, d/Rh. Strong HI (OVI) absorption systems with column densities greater than 10^14.0^ (10^13.5^)cm^-2^ are found for 48 of 54 (36 of 42) galaxies at d<Rh indicating a mean covering fraction of <{kappa}_HI_>=0.89 (<{kappa}_OVI_>=0.86). OVI absorbers are found at d~Rh, beyond the extent observed for lower ionization species. At d/Rh=1-3 strong HI (OVI) absorption systems are found for only 7 of 43 (5 of 34) galaxies (<{kappa}_HI_>=0.16 and <{kappa}_OVI_>=0.15). Beyond d=3Rh, the HI and OVI covering fractions decrease to levels consistent with coincidental systems. The high completeness of the galaxy survey enables an investigation of environmental dependence of extended gas properties. Galaxies with nearby neighbours exhibit a modest increase in Ovi covering fraction at d>Rh compared to isolated galaxies (<{kappa}_OVI_~0.13 versus 0.04) but no excess HI absorption. These findings suggest that environmental effects play a role in distributing heavy elements beyond the enriched gaseous haloes of individual galaxies. Finally, we find that differential HI and OVI absorption between early- and late-type galaxies continues from d<Rh to d~3Rh.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A119
- Title:
- Extended halo of NGC 2682 (M 67)
- Short Name:
- J/A+A/627/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- NGC 2682 is a nearby open cluster that is approximately 3.5Gyr old. Dynamically, most open clusters are expected to dissolve on shorter timescales of ~=1Gyr. That it has survived until now means that NGC 2682 was likely much more massive in the past and is bound to have an interesting dynamical history. We investigate the spatial distribution of the stars in NGC 2682 to constrain dynamical evolution of the cluster. We particularly focus on the marginally bound stars in the cluster outskirts. We used Gaia DR2 data to identify NGC 2682 members up to a distance of ~150pc (10{deg}). The two methods Clusterix and UPMASK were applied to this end. We estimated distances to obtain 3D stellar positions using a Bayesian approach to parallax inversion, with an appropriate prior for star clusters. We calculated the orbit of NGC 2682 using the GRAVPOT16 software. The cluster extends up to 200' (50pc), which implies that its size is at least twice as large as previously believed. This exceeds the cluster Hill sphere based on the Galactic potential at the distance of NGC 2682. The extra-tidal stars in NGC 2682 may originate from external perturbations such as disc-shocking or dynamical evaporation from two-body relaxation. The former origin is plausible given the orbit of NGC 2682, which crossed the Galactic disc ~=40Myr ago.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/4364
- Title:
- Extended H2 emission from massive YSOs survey
- Short Name:
- J/MNRAS/450/4364
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a survey, designed to investigate the accretion process of massive young stellar objects (MYSOs) through near infrared narrow band imaging using the H_2_ {nu}=1-0 S(1) transition filter. A sample of 353 Massive Young Stellar Object (MYSO) candidates was selected from the Red MSX Source survey using photometric criteria at longer wavelengths (infrared and submillimeter) and chosen with positions throughout the Galactic Plane. Our survey was carried out at the SOAR Telescope in Chile and CFHT in Hawaii covering both hemispheres.
- ID:
- ivo://CDS.VizieR/V/137D
- Title:
- Extended Hipparcos Compilation (XHIP)
- Short Name:
- V/137D
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Extended Hipparcos Compilation (XHIP) cross-references the New Hipparcos Reduction (HIP2, Cat. I/311) with relatable data from a broad survey of presently available sources. The resulting collection uniquely assigns 116,096 spectral classifications, 46,392 radial velocities, and 19,097 iron abundances [Fe/H] to Hipparcos stars. Stellar classifications from SIMBAD and indications of multiplicity from either CCDM (Cat. I/274) or WDS (Cat. B/wds) are provided. Parameters for solar encounters and Galactic orbits are calculated for a subset of stars that can be made kinematically complete. Memberships in open clusters and stellar associations are assigned. We also provide stellar ages from The Geneva-Copenhagen survey of the Solar neighbourhood III (Cat. V/130), identifications of exoplanet host stars, and supplemental photometry from 2MASS (Cat. II/246) and SIMBAD.
- ID:
- ivo://CDS.VizieR/J/A+A/632/A74
- Title:
- Extended main-sequence turn-offs isochrones
- Short Name:
- J/A+A/632/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Extended main-sequence turn-offs (eMSTO) are a commonly observed property of young clusters. A global theoretical interpretation for the eMSTOs is still lacking, but stellar rotation is considered a necessary ingredient to explain the eMSTO. We aim to assess the importance of core-boundary and envelope mixing in stellar interiors for the interpretation of eMSTOs in terms of one coeval population. We construct isochrone-clouds based on interior mixing profiles of stars with a convective core calibrated from asteroseismology of isolated galactic field stars. We fit these isochrone-clouds to the measured eMSTO to estimate the age and core mass of the stars in the two young clusters NGC 1850 and NGC 884, assuming one coeval population and fixing the metallicity to the one measured from spectroscopy. We assess the correlations between the interior mixing properties of the cluster members and their rotational and pulsational properties. We find that stellar models based on asteroseismically-calibrated interior mixing profiles lead to enhanced core masses of eMSTO stars and can explain a good fraction of the observed eMSTOs of the two considered clusters in terms of one coeval population of stars, with similar ages to those in the literature, given the large uncertainties. The rotational and pulsational properties of the stars in NGC 884 are not sufficiently well known to perform asteroseismic modelling, as it is achieved for field stars from space photometry. The stars in NGC 884 for which we have vsini and a few pulsation frequencies show no correlation between these properties and the core masses of the stars that set the cluster age. Future cluster space asteroseismology may allow to interpret the values of the core masses in terms of the physical processes that cause them, based on the modelling of the interior mixing profiles for the individual member stars with suitable identified modes.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A64
- Title:
- Extended Meingast 1 source catalogue
- Short Name:
- J/A+A/639/A64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Nearby stellar streams carry unique information on the dynamical evolution and disruption of stellar systems in the Galaxy, the mass distribution in the disk, and they provide unique targets for planet formation and evolution studies. Recently, Meingast 1, a 120{deg} stellar stream with a length of at least 400pc, was discovered. We aim to revisit the Meingast 1 stream to search for new members within its currently known 400pc extent, using Gaia DR2 data and an innovative machine learning approach. We used a bagging classifier of one-class support vector machines with Gaia DR2 data to perform a 5D search (positions and proper motions) for new stream members. The ensemble was created by randomly sampling 2.4 million hyper-parameter realizations admitting classifiers that fulfill a set of prior assumptions. We used the variable prediction frequency resulting from the multitude of classifiers to estimate a stream membership criterion, which we used to select high-fidelity sources. We used the HR diagram and the Cartesian velocity distribution as test and validation tools. We find about 2000 stream members with high fidelity, or about an order of magnitude more than previously known, unveiling the stream's population across the entire stellar mass spectrum, from B stars to M stars, including white dwarfs. We find that, apart from being slightly more metal poor, the HRD of the stream is indistinguishable from that of the Pleiades cluster. For the mass range at which we are mostly complete, ~0.2M_{sun}_<M<~4M_{sun}_, we find a normal IMF, allowing us to estimate the total mass of stream to be about 2000M_{sun}_, making this relatively young stream by far the most massive one known. In addition, we identify several white dwarfs as potential stream members. The nearby Meingast 1 stream, due to its richness, age, and distance, is a new fundamental laboratory for star and planet formation and evolution studies for the poorly studied and gravitationally unbound star formation mode. We also demonstrate that one-class support vector machines can be effectively used to unveil the full stellar populations of nearby stellar systems with Gaia data.