- ID:
- ivo://CDS.VizieR/J/ApJS/240/17
- Title:
- Exoplanets in the Antarctic sky. II. 116 candidates
- Short Name:
- J/ApJS/240/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report first results from the CHinese Exoplanet Searching Program from Antarctica (CHESPA)--a wide-field high-resolution photometric survey for transiting exoplanets carried out using telescopes of the AST3 (Antarctic Survey Telescopes times 3) project. There are now three telescopes (AST3-I, AST3-II, and CSTAR-II) operating at Dome A --the highest point on the Antarctic Plateau-- in a fully automatic and remote mode to exploit the superb observing conditions of the site, and its long and uninterrupted polar nights. The search for transiting exoplanets is one of the key projects for AST3. During the austral winters of 2016 and 2017 we used the AST3-II telescope to survey a set of target fields near the southern ecliptic pole, falling within the continuous viewing zone of the TESS mission. The first data release of the 2016 data, including images, catalogs, and light curves of 26578 bright stars (7.5<=m_i_<=15), was presented in Zhang+ (2018, J/ApJS/240/16). The best precision, as measured by the rms of the light curves at the optimum magnitude of the survey (m_i_=10), is around 2mmag. We detect 222 objects with plausible transit signals from these data, 116 of which are plausible transiting exoplanet candidates according to their stellar properties as given by the TESS Input Catalog, Gaia DR2, and TESS-HERMES spectroscopy. With the first data release from TESS expected in late 2018, this candidate list will be timely for improving the rejection of potential false-positives.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/498/5720
- Title:
- Extended Breakthrough Listen sample
- Short Name:
- J/MNRAS/498/5720
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We extend the source sample recently observed by the Breakthrough Listen Initiative by including additional stars (with parallaxes measured by Gaia) that also reside within the FWHM of the GBT and Parkes radio telescope target fields. These stars have estimated distances as listed in the extensions of the Gaia DR2 catalogue. Enlarging the sample from 1327 to 288315 stellar objects permits us to achieve substantially better Continuous Waveform Transmitter Rate Figures of Merit (CWTFM) than any previous analysis, and allows us to place the tightest limits yet on the prevalence of nearby high-duty-cycle extraterrestrial transmitters. The results suggest <~0.0660(+0.0004,-0.0003)% of stellar systems within 50 pc host such transmitters (assuming an EIRP>~10^13^W) and <~0.039(+0.004,-0.008)% within 200pc (assuming an EIRP>~2.5*10^14^W). We further extend our analysis to much greater distances, though we caution that the detection of narrow-band signals beyond a few hundred pc may be affected by interstellar scintillation. The extended sample also permits us to place new constraints on the prevalence of extraterrestrial transmitters by stellar type and spectral class. Our results suggest targeted analyses of SETI radio data can benefit from taking into account the fact that in addition to the target at the field centre, many other cosmic objects reside within the primary beam response of a parabolic radio telescope. These include foreground and background galactic stars, but also extragalactic systems. With distances measured by Gaia, these additional sources can be used to place improved limits on the prevalence of extraterrestrial transmitters, and extend the analysis to a wide range of cosmic objects.
- ID:
- ivo://CDS.VizieR/J/AJ/131/2373
- Title:
- Extended Chandra Deep Field-South survey
- Short Name:
- J/AJ/131/2373
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Extended Chandra Deep Field-South (ECDFS) survey consists of four Chandra X-Ray Observatory ACIS-I pointings and covers ~1100arcmin^2^ (~0.3{deg}^2^) centered on the original CDF-S field to a depth of approximately 228ks. 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 2.0-8.0keV band. We detect 651 unique sources: 587 using a conservative source-detection threshold and 64 using a lower source-detection threshold. These are presented as two separate catalogs. Of the 651 total sources, 561 are detected in the full 0.5-8.0keV band, 529 in the soft 0.5-2.0keV band, and 335 in the hard 2.0-8.0keV band. For point sources near the aim point, the limiting fluxes are approximately 1.7x10^-16^ and 3.9x10^-16^ergs/cm^2^/s in the 0.5-2.0 and 2.0-8.0keV bands, respectively. Using simulations, we determine the catalog completeness as a function of flux and assess uncertainties in the derived fluxes due to incomplete spectral information. We 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.
- 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/AJ/131/2859
- Title:
- Extragalactic First Look Survey: 24{mu}m data
- Short Name:
- J/AJ/131/2859
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the reduction of the 24{mu}m data obtained during the first cosmological survey performed by the Spitzer Space Telescope. Images of a region of sky at moderately high Galactic latitude (l=88.3{deg}, b=+34.9{deg}) were obtained on 2003 December 9-11. The survey consists of a shallow observation of 2.5x2{deg}^2^ centered at 17:18 +59:30 (main survey) and a deeper observation of 1{deg}x0.5{deg} centered at 17:17 +59:45 (verification survey). Issues with the reduction of the 24{mu}m MIPS data are discussed and solutions to attenuate instrumental effects are proposed and applied to the data. Approximately 17000 sources are extracted with a signal-to-noise ratio (S/N) greater than 5. The photometry of the point sources is evaluated through point-spread function (PSF) fitting using an empirical PSF derived from the data. Aperture corrections and the absolute calibration have been checked using stars in the field. Astrometric and photometric errors depend on the S/N of the source varying between 0.35"-1" and 5%-15%, respectively, for sources detected at 20-5{sigma}. The fluxes of the 123 extended sources have been estimated through aperture photometry. The extended sources cover less than 0.3% of the total area of the survey. Based on simulations, the main and verification surveys are 50% complete at 0.3 and 0.15mJy, respectively. Counterparts have been searched for in optical and radio catalogs.
- ID:
- ivo://CDS.VizieR/J/ApJ/694/222
- Title:
- Extragalactic point sources in WMAP 5-yr maps
- Short Name:
- J/ApJ/694/222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an extragalactic point source search using the five-year Wilkinson Microwave Anisotropy Probe (WMAP) 41, 61, and 94GHz (Q, V, and W bands) temperature maps. This work is an extension of our designing and applying a cosmic microwave background (CMB)-free technique to extract point sources in the WMAP maps. Specifically, we have formed an internal linear combination map of the three-band maps, with the weights chosen to remove the CMB anisotropy signal as well as to favor the selection of flat-spectrum sources. We have also constructed a filter to recover the true point source flux distribution on the sky. A total of 381 sources are found in our study at the >5{sigma} level outside the WMAP point source detection mask, among which 89 are "new" (i.e., not present in the WMAP catalogs). Source fluxes have been calculated and corrected for the Eddington bias. We have solidly identified 367 (96.3%) of our sources, the 1{sigma} positional uncertainty of which is 2'. The 14 unidentified sources could be either extended radio structure or obscured by Galactic emission. We have also applied the same detection approach to simulated maps, which yielded 364+/-21 detections on average. The recovered source distribution N(>S) agrees well with the simulation input, which proves the reliability of this method.
- ID:
- ivo://CDS.VizieR/J/ApJ/681/747
- Title:
- Extragalactic point-source WMAP catalog
- Short Name:
- J/ApJ/681/747
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of an extragalactic point-source search using the 61 and 94GHz (V- and W-band) temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP). Applying a method that cancels the "noise" due to the CMB anisotropy signal, we find in the |b|>10{deg} region 31 sources in the first-year maps and 64 sources in the three-year co-added maps at a 5{sigma} level. The 1{sigma} position uncertainties are 1.6' and 1.4', respectively. The increased detections and improved positional accuracy are expected from the higher signal-to-noise ratio of the WMAP three-year data. All sources detected in the first-year maps are repeatedly detected in the three-year maps, which is a strong indication of the consistency of this method. Of all the sources, 97% are identified with either the WMAP three-year source catalog or plausible extrapolations of lower frequency data, which indicates that our method is also reliable. The two unidentified sources have been recently confirmed to be false detections, using the WMAP five-year data. We derive the source count distribution at the WMAP V band by combining our verified detections with sources from the WMAP three-year catalog. If we assume that the effect of source clustering is negligible, the contribution to the power spectrum from faint sources below 0.75Jy is estimated to be (2.4+/-0.8)x10^-3^uK^2^sr for the V band, which implies a source correction amplitude of A=0.012+/-0.004uK^2^sr.
- ID:
- ivo://CDS.VizieR/J/MNRAS/371/898
- Title:
- Extragalactic radio sources selected at 20GHz
- Short Name:
- J/MNRAS/371/898
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present some first results on the variability, polarization and general properties of radio sources selected at 20GHz, the highest frequency at which a sensitive radio survey has been carried out over a large area of sky. Sources with flux densities above 100mJy in the Australia Telescope Compact Array 20GHz pilot survey at declination 60{deg} to 70{deg} were observed at up to three epochs during 2002-04, including near-simultaneous measurements at 5, 8 and 18GHz in 2003. Of the 173 sources detected, 65 per cent are candidate QSOs or BL Lac objects, 20 per cent galaxies and 15 per cent faint (bJ>22mag) optical objects or blank fields.
- ID:
- ivo://CDS.VizieR/J/ApJ/801/143
- Title:
- Extrasolar Kuiper belts from Herschel
- Short Name:
- J/ApJ/801/143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study of the planet-debris disk connection can shed light on the formation and evolution of planetary systems and may help "predict" the presence of planets around stars with certain disk characteristics. In preliminary analyses of subsamples of the Herschel DEBRIS and DUNES surveys, Wyatt et al. (2012MNRAS.424.1206W) and Marshall et al. (2014A&A...565A..15M) identified a tentative correlation between debris and the presence of low-mass planets. Here we use the cleanest possible sample out of these Herschel surveys to assess the presence of such a correlation, discarding stars without known ages, with ages <1Gyr, and with binary companions <100AU to rule out possible correlations due to effects other than planet presence. In our resulting subsample of 204 FGK stars, we do not find evidence that debris disks are more common or more dusty around stars harboring high-mass or low-mass planets compared to a control sample without identified planets.
- ID:
- ivo://archive.stsci.edu/euve
- Title:
- Extreme Ultraviolet Explorer
- Short Name:
- EUVE
- Date:
- 22 Jul 2020 21:28:51
- Publisher:
- Space Telescope Science Institute Archive
- Description:
- Launched in June, 1992, The Extreme Ultraviolet Explorer (EUVE) conducted the first extreme ultraviolet (70-760 Angstroms) survey of the sky and subsequently began a Guest Observer Program of pointed
