- ID:
- ivo://CDS.VizieR/J/ApJS/237/38
- Title:
- Extended abundance analysis of KOIs
- Short Name:
- J/ApJS/237/38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate stellar parameters and precise elemental abundances are vital pieces to correctly characterize discovered planetary systems, better understand planet formation, and trace galactic chemical evolution. We have performed a uniform spectroscopic analysis for 1127 stars, yielding accurate gravity, temperature, and projected rotational velocity in addition to precise abundances for 15 elements (C, N, O, Na, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Ni, and Y). Most of the stars in this sample are Kepler Objects of Interest, observed by the California-Kepler Survey, and include 1003 stars hosting 1562 confirmed planets. This catalog extends the uniform analysis of our previous catalog, bringing the total number of homogeneously analyzed stars to almost 2700 F, G, and K dwarfs. To ensure consistency between the catalogs, we performed an analysis of our ability to recover parameters as a function of signal-to-noise ratio (S/N) and present individual uncertainties as well as functions to calculate uncertainties for parameters derived from lower S/N spectra. With the updated parameters, we used isochrone fitting to derive new radii, masses, and ages for the stars. We use our abundance analysis to support the finding that the radius gap is likely a result of evolution rather than the result of primordial compositional differences between the two populations.
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- ID:
- ivo://CDS.VizieR/J/A+A/483/339
- Title:
- Extended analysis of the Eu III spectrum
- Short Name:
- J/A+A/483/339
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We create an Eu III new atomic data set for interpreting the spectra of chemically peculiar stars by an extended analysis of the doubly-ionized europium. We classified Eu III spectral lines from a laboratory wavelength list with the support of energy and transition probability predictions in the Racah-Slater approach, using the Cowan codes and generalized least-squares fit (GLS) studies along the sequence of doubly-ionized lanthanides.
- ID:
- ivo://CDS.VizieR/J/ApJS/244/32
- Title:
- Extended Aperture Photometry of K2 RR Lyrae stars
- Short Name:
- J/ApJS/244/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Kepler Space Telescope observed thousands of RR Lyrae stars in the K2 mission. In this paper, we present our photometric solutions using extended apertures in order to conserve the flux of the stars to the highest possible extent. With this method, we are able to avoid most of the problems that RR Lyrae light curves produced by other pipelines suffer from. For post-processing, we apply the K2SC pipeline to our light curves. We provide the EAP (Extended Aperture Photometry) of 432 RR Lyrae stars observed in campaigns 3, 4, 5, and 6. We also provide subclass classifications based on Fourier parameters. We investigated in particular the presence of the Blazhko effect in the stars and found it to be 44.7% among the RRab stars, in agreement with results from independent samples. We found that the amplitude and phase modulation in the Blazhko stars may behave rather differently, at least over the length of a K2 Campaign. We also identified four anomalous Cepheid candidates in the sample, one of which is potentially the first Blazhko-modulated member of its class.
- 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/other/OEJV/87
- Title:
- Extended catalog of NSVS red AGB variable stars
- Short Name:
- J/other/OEJV/87
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- In this paper we present the catalog of new Mira-type and SR+L variable stars in the Northern Sky Variability Survey (NSVS) database, found after complementing the original NSVS object tables with a number of additional parameters. By extending the amount of criteria search queries can take advantage of and filtering known objects out, it became convenient to apply better constrained filters to search new variable star candidates. As an example of presented approach, the quest for red variables has resulted in 78 Mira-type and 717 SR+L stars found that have no identification in General Catalogue of Variable Stars, SIMBAD and VSX databases. Most likely the stars presented are new discoveries. The classification of these stars is based on the near-infrared colors from Two Micron All Sky Survey (2MASS) photometry, amplitude and period with the accuracy of the classification given ~90%, estimated basing on the current GCVS classification scheme.
- ID:
- ivo://nasa.heasarc/ecdfsnew
- Title:
- Extended Chandra Deep Field South 250-ks Improved Point Source Catalog
- Short Name:
- ECDFSNEW
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the improved point-source catalog for the 250-ks Extended Chandra Deep Field-South (E-CDF-S) Survey, implementing a number of recent improvements in Chandra source-cataloguing methodology. For the E-CDF-S, the main catalog (entries from which are indicated with parameter values of source_sample = "Main" in this HEASARC representation) contains 1003 X-ray sources detected with wavdetect at a false-positive probability threshold of 10<sup>-5</sup> that also satisfy a binomial-probability source-selection criterion of P < 0.002. Such an approach maximizes the number of reliable sources detected: a total of 275 main-catalog sources are new compared to the Lehmer et al. (2005, ApJS, 161, 21) E-CDF-S main catalog. The authors also provide an E-CDF-S supplementary catalog that consists of 56 sources (entries from which are indicated with parameter values of source_sample = "Supp" in this HEASARC representation) detected at the same wavdetect threshold and having P of 0.002-0.1 and K<sub>s</sub> <= 22.3 mag counterparts. For all 1059 E-CDF-S sources, including the 318 newly detected ones (these being generally fainter and more obscured), the authors determine X-ray source positions utilizing centroid and matched-filter techniques; they also provide multi-wavelength identifications, apparent magnitudes of counterparts, spectroscopic and/or photometric redshifts, basic source classifications, and estimates of observed active galactic nucleus and galaxy source densities around respective field centers. Simulations show that the E-CDF-S main catalog is highly reliable and reasonably complete. Background and sensitivity analyses indicate that the on-axis mean flux limits reached represent a factor of ~1.5-2.0 improvement over the previous E-CDF-S limit. The 250-ks E-CDF-S is composed of four distinct and contiguous ~ 250-ks Chandra pointings that flank the CDF-S proper, consisting of a total of nine separate observations taken between 2004 February 29 and November 20 (see Lehmer et al., 2005, ApJS, 161, 21 for more details). This table was created by the HEASARC in August 2016 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/224/15">CDS Catalog J/ApJS/224/15</a> files table9.dat (the main source catalog) and table12.dat (the supplementary source catalog). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ecdfsoid2
- Title:
- Extended Chandra Deep Field-South Optical and Near-IR Counterparts
- Short Name:
- ECDFSOID2
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of a program to acquire high-quality optical spectra of X-ray sources detected in the Extended-Chandra Deep Field-South (E-CDF-S) and its central 2 Ms area. New spectroscopic redshifts, up to z = 4, are measured for 283 counterparts to Chandra sources with deep exposures (t ~ 2-9 hr per pointing) using multi-slit facilities on both VLT (VIMOS) and Keck (DEIMOS), thus bringing the total number of spectroscopically identified X-ray sources to over 500 in this survey field. Since their new spectroscopic identifications are mainly associated with X-ray sources in the shallower 250 ks coverage, the authors provide a comprehensive catalog of X-ray sources detected in the E-CDF-S including the optical and near-infrared counterparts, determined by a likelihood routine, and redshifts (both spectroscopic and photometric), that incorporate published spectroscopic catalogs, thus resulting in a final sample with a high fraction (80%) of X-ray sources having secure identifications. The authors demonstrate the remarkable coverage of the luminosity-redshift plane now accessible from their data while emphasizing the detection of active galactic nuclei (AGNs) that contribute to the faint end of the luminosity function (L<sub>0.5-8keV</sub> ~ 10<sup>43</sup> - 10<sup>44</sup> erg s<sup>-1</sup>) at 1.5 <~ z <~ 3, including those with and without broad emission lines. This redshift catalog includes 17 type-2 QSOs at 1 <~ z <~ 3.5 that significantly increases (doubles) such samples. Based on thei deepest (9 hr) VLT/VIMOS observation, the authors identify "elusive" optically faint galaxies (R<sub>mag</sub> ~ 25) at z ~ 2 - 3 based upon the detection of interstellar absorption lines (e.g., O II+Si IV, C II], C IV); in their paper, they highlight one such case, an absorption-line galaxy at z = 3.208 having no obvious signs of an AGN in its optical spectrum. In addition, they determine accurate distances to eight galaxy groups with extended X-ray emission detected both by Chandra and XMM-Newton. This online catalog was created by the HEASARC in November 2010 based on a machine-readable version of Table 4 from the paper which was obtained from the ApJ website. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJS/161/21
- Title:
- Extended Chandra Deep Field-South survey
- Short Name:
- J/ApJS/161/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Chandra point-source catalogs for the Extended Chandra Deep Field-South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250ks Chandra observations covering an approximately square region of total solid angle ~0.3{deg}^2^, which flank the existing ~1Ms Chandra Deep Field-South (CDF-S). The survey reaches sensitivity limits of ~1.1x10^-16^ and ~6.7x10^-16^ergs/cm^2^/s for the 0.5-2.0 and 2-8keV bands, respectively. We detect 762 distinct X-ray point sources within the E-CDF-S exposure; 589 of these sources are new (i.e., not previously detected in the ~1Ms CDF-S). This brings the total number of X-ray point sources detected in the E-CDF-S region to 915 (via the E-CDF-S and ~1Ms CDF-S observations). Source positions are determined using matched-filter and centroiding techniques; the median positional uncertainty is ~0.35". In addition to our main Chandra catalog, we constructed a supplementary source catalog containing 33 lower significance X-ray point sources that have bright optical counterparts (R<23).
- 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://nasa.heasarc/ecdfsoid
- Title:
- Extended Chandra Deep Field-South Survey Optical Identifications Catalog
- Short Name:
- ECDFSOID
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the first results of the authors' optical spectroscopy program aimed to provide redshifts and identifications for the X-ray sources in the Extended Chandra Deep Field South (ECDFS). A total of 339 sources (listed herein) were targeted using the IMACS spectrograph at the Magellan telescopes and the VIMOS spectrograph at the VLT. The authors have measured redshifts for 186 X-ray sources, including archival data and a literature search. They find that the active galactic nucleus (AGN) host galaxies have on average redder rest-frame optical colors than nonactive galaxies, and that they live mostly in the "green valley." The dependence of the fraction of AGNs that are obscured on both luminosity and redshift is confirmed at high significance and the observed AGN spatial density is compared with the expectations from existing luminosity functions. These AGNs show a significant difference in the mid-IR to X-ray flux ratio for obscured and unobscured AGNs, which can be explained by the effects of dust self-absorption on the former. This difference is larger for lower luminosity sources, which is consistent with the dust opening angle depending on AGN luminosity. This table was created by the HEASARC in April 2009 based on the electronic version of Table 2 from the Treister et al. (2009) paper obtained from the ApJ web site, except for the source positions which were taken from Virani et al. (2006). The full table from the latter paper is also available in Browse (the ECDFSCXO table). This is a service provided by NASA HEASARC .