- ID:
- ivo://CDS.VizieR/VIII/58
- Title:
- A Survey of Radio H II Regions in the Northern Sky
- Short Name:
- VIII/58
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Nearly 500 radio continuum sources near the Galactic plane at declinations greater than -37 degrees were examined for radio recombination line emission to see if they might be HII regions. A total of 462 were detected, about half of these for the first time. The data are presented in an extensive table. Among the newly discovered nebulae are several with recombinations lines so narrow that their electron temperature must be less than 4600 K. In one case the line width (in several transitions) is only 11.6 km/s, requiring electron temperatures less than about 2900 K.
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- ID:
- ivo://CDS.VizieR/J/ApJS/190/1
- Title:
- A survey of stellar families
- Short Name:
- J/ApJS/190/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a comprehensive assessment of companions to solar-type stars. A sample of 454 stars, including the Sun, was selected from the Hipparcos catalog with {pi}>40mas, {sigma}{pi}/{pi}<0.05, 0.5<=B-V<=1.0 (~F6-K3), and constrained by absolute magnitude and color to exclude evolved stars. These criteria are equivalent to selecting all dwarf and subdwarf stars within 25pc with V-band flux between 0.1 and 10 times that of the Sun, giving us a physical basis for the term "solar-type". New observational aspects of this work include surveys for (1) very close companions with long-baseline interferometry at the Center for High Angular Resolution Astronomy Array, (2) close companions with speckle interferometry, and (3) wide proper-motion companions identified by blinking multi-epoch archival images. In addition, we include the results from extensive radial-velocity monitoring programs and evaluate companion information from various catalogs covering many different techniques. The results presented here include four new common proper-motion companions discovered by blinking archival images. Additionally, the spectroscopic data searched reveal five new stellar companions. Our synthesis of results from many methods and sources results in a thorough evaluation of stellar and brown dwarf companions to nearby Sun-like stars. The overall observed fractions of single, double, triple, and higher-order systems are 56%+/-2%, 33%+/-2%, 8%+/-1%, and 3%+/-1%, respectively, counting all confirmed stellar and brown dwarf companions.
- ID:
- ivo://CDS.VizieR/J/AJ/127/1567
- Title:
- Asymmetric thick disk. II. Kinematics
- Short Name:
- J/AJ/127/1567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report a kinematic signature associated with the observed asymmetry in the distribution of thick-disk/inner halo stars interior to the solar circle described in Paper I (Parker et al., 2003AJ....126.1346P). In that paper, we found a statistically significant excess (20%-25%) of stars in quadrant I (l~20{deg}-55{deg}) both above and below the plane (b~+/-25{deg} to b~+/-45{deg}) compared with the complementary region in quadrant IV. We have measured Doppler velocities for 741 stars, selected according to the same magnitude and color criteria, in the direction of the asymmetry and in the corresponding fields in quadrant IV. We have also determined spectral types and metallicities measured from the same spectra.
- ID:
- ivo://CDS.VizieR/J/ApJ/857/119
- Title:
- Asymmetry of oscillations in 43 Kepler stars
- Short Name:
- J/ApJ/857/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Oscillation properties are usually measured by fitting symmetric Lorentzian profiles to the power spectra of Sun-like stars. However, the line profiles of solar oscillations have been observed to be asymmetrical for the Sun. The physical origin of this line asymmetry is not fully understood; though, it should depend on the depth dependence of the source of wave excitation (convective turbulence) and details of the observable (velocity or intensity). For oscillations of the Sun, it has been shown that neglecting the asymmetry leads to systematic errors in the frequency determination. This could subsequently affect the results of seismic inferences of the solar internal structure. Using light curves from the Kepler spacecraft, we have measured mode asymmetries in 43 stars. We confirm that neglecting the asymmetry leads to systematic errors that can exceed the 1{sigma} confidence intervals for seismic observations longer than one year. Therefore, the application of an asymmetric Lorentzian profile should be favored to improve the accuracy of the internal stellar structure and stellar fundamental parameters. We also show that the asymmetry changes sign between cool Sun-like stars and hotter stars. This provides the best constraints to date on the location of the excitation sources across the Hertzsprung-Russel diagram.
- ID:
- ivo://nasa.heasarc/actsouth
- Title:
- Atacama Cosmology Telescope (ACT) Extragalactic Southern Sources Catalog
- Short Name:
- ACTSOUTH
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The ACTSOUTH catalog is a multi-frequency, multi-epoch catalog of extragalactic sources, based on 150, 220 and 280 GHz observations carried out in 2008, 2009 and 2010 using the Millimeter Bolometric Array Camera on the Atacama Cosmology Telescope. The catalog contains 695 sources, found in a sky area of ~600 square degrees. It is obtained by cross-matching sources found in 11 sub-catalogs, one for each season and frequency band. Also include are co-added data from ~150 and ~160 square degrees using 2 and 3 years of overlapping observations. The authors divide the sources into two populations, synchrotron and dusty emitters, based on their spectral behavior in the 150 - 220 GHz frequency range. They find 374 synchrotron sources and 321 dusty source candidates. Cross-matching with catalogs from radio to X-ray results in 264 synchrotron sources (71%) and 89 dusty sources (28%) with counterparts, suggesting that 232 dusty candidates are not in existing catalogs. This table was ingested by the HEASARC in November 2023 based upon the files downloaded from the LAMBDA archive at <a href="https://lambda.gsfc.nasa.gov/product/act/act_south_cat_get.html">https://lambda.gsfc.nasa.gov/product/act/act_south_cat_get.html</a>. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/actszclust
- Title:
- Atacama Cosmology Telescope DR5 Sunyaev-Zeldovich Cluster Catalog
- Short Name:
- ACTSZCLUST
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The catalog of 4195 optically confirmed Sunyaev-Zel'dovich (SZ) selected galaxy clusters were detected with signal-to-noise > 4 in 13,211 deg<sup>2</sup> of sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were selected by applying a multi-frequency matched filter to 98- and 150-GHz maps constructed from ACT observations obtained from 2008-2018 and confirmed using deep, wide-area optical surveys. The clusters span the redshift range 0.04 < z < 1.91 (median z = 0.52). The catalog contains 222 z > 1 clusters, and a total of 868 systems are new discoveries. Assuming an SZ-signal vs. mass scaling relation calibrated from X-ray observations, the sample has a 90% completeness mass limit of M<sub>500c</sub> > 3.8 x 10<sup>14</sup>M<sub>sol</sub>, evaluated at z=0.5, for clusters detected at signal-to-noise ratio > 5 in maps filtered at an angular scale of 2.40. The survey has a large overlap with deep optical weak-lensing surveys that are being used to calibrate the SZ-signal mass-scaling relation, such as the Dark Energy Survey (4566 deg<sup>2</sup>), the Hyper Suprime-Cam Subaru Strategic Program (469 deg<sup>2</sup>), and the Kilo Degree Survey (825 deg<sup>2</sup>). This HEASARC database table was ingested in February 2021. It contains the ACT DR5 SZ cluster catalog obtained from the LAMDBA website (<a href="https://lambda.gsfc.nasa.gov/product/act/actpol_dr5_szcluster_catalog_info.cfm#catalog">https://lambda.gsfc.nasa.gov/product/act/actpol_dr5_szcluster_catalog_info.cfm#catalog</a>). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/actssrcat
- Title:
- Atacama Cosmology Telescope 2008 Southern Survey 148/218 GHz Source Catalog
- Short Name:
- ACTSSRCAT
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of 191 extragalactic sources detected by the Atacama Cosmology Telescope (ACT) at 148 and/or 218 GHz in the 2008 Southern survey. Flux densities span 14 -1700 mJy, and the authors use source spectral indices derived using ACT-only data to divide their sources into two subpopulations: 167 radio galaxies powered by central active galactic nuclei (AGN) and 24 dusty star-forming galaxies (DSFGs). They cross-identify 97% of their sources (166 of the AGN and 19 of the DSFGs) with those in currently available catalogs. When combined with flux densities from the Australia Telescope 20-GHz survey and follow-up observations with the Australia Telescope Compact Array, the synchrotron-dominated population is seen to exhibit a steepening of the slope of the spectral energy distribution from 20 to 148 GHz, with the trend continuing to 218 GHz. The ACT dust-dominated source population has a median spectral index, alpha<sub>148-218GHz</sub>, of 3.7<sup>+0.62</sup><sub>-0.86</sub>, and includes both local galaxies and sources with redshift around 6. Dusty sources with no counterpart in existing catalogs likely belong to a recently discovered subpopulation of DSFGs lensed by foreground galaxies or galaxy groups. The ACT experiment (Swetz et al., 2011, ApJS, 194, 41) is situated on the slopes of Cerro Toco in the Atacama Desert of Chile at an elevation of 5190m. ACT's latitude gives access to both the northern and southern celestial hemispheres. Observations occurred simultaneously in three frequency bands, at 148 GHz (2.0 mm), 218 GHz (1.4 mm) and 277 GHz (1.1 mm) with angular resolutions of roughly 1.4, 1.0 and 0.9 arcminutes, respectively. The ACT-detected source list contains 169 sources selected at 148 GHz with S/N > 5, spanning two decades in flux density, from 14 to 1700 mJy. The 218 GHz map independently yielded 133 sources with S/N > 5. The combination of these two independent source lists from which the present table was constructed gives a total count of 191 sources, with 110 galaxies detected with S/N > 5 at both frequencies. This table was created by the HEASARC in May 2015 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/439/1556/">CDS Catalog J/MNRAS/439/1556/</a> file table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/actegsrcat
- Title:
- Atacama Cosmology Telescope 2008 Survey 148-GHz Extragalactic Source Catalog
- Short Name:
- ACTEGSRCAT
- Date:
- 02 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a list of extragalactic radio sources detected in a 455 square-degree map of the southern sky made at a frequency of 148 GHz from the Atacama Cosmology Telescope (ACT) 2008 observing season. This catalog has 157 sources with flux densities spanning two orders of magnitude from 15 to 1500 mJy. Comparison to other catalogs shows that 98% of the ACT detections correspond to sources detected at lower radio frequencies. Three of the sources appear to be associated with the brightest cluster galaxies of low redshift X-ray selected galaxy clusters. Estimates of the radio to mm-wave spectral indices and differential counts of the sources further bolster the hypothesis that they are nearly all radio sources, and that their emission is not dominated by re-emission from warm dust. In a bright (>50 mJy) 148 GHz-selected sample with complete cross-identifications from the Australia Telescope 20-GHz survey, the authors of the study observe an average steepening of the spectra between 5, 20, and 148 GHz with median spectral indices of alpha<sub>5-20</sub> = -0.07 +/- 0.06, alpha<sub>20-148</sub> = -0.39 +/- 0.04, and alpha<sub>5-148</sub> = -0.20 +/- 0.03. When the measured spectral indices are taken into account, the 148-GHz differential source counts are consistent with previous measurements at 30 GHz in the context of a source count model dominated by flat spectrum radio sources. Extrapolating with an appropriately rescaled model for the radio source counts, the Poisson contribution to the spatial power spectrum from synchrotron-dominated sources with flux density less than 20 mJy is C<sub>Sync</sub> = (2.8 +/- 0.3) x 10<sup>-6</sup> microKelvin<sup>2</sup>. This table was created by the HEASARC in January 2011 based on an electronic version of Table A1 from the paper (the Point Source Catalog) which was obtained from the LAMBDA website at <a href="http://lambda.gsfc.nasa.gov/product/suborbit/act_prod_table.cfm">http://lambda.gsfc.nasa.gov/product/suborbit/act_prod_table.cfm</a> This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/A+A/445/465
- Title:
- ATCA 18.5 and 22GHz fluxes of Kuehr 5GHz sample
- Short Name:
- J/A+A/445/465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss our ATCA 18.5 and 22GHz flux density measurements of Southern extragalactic sources in the complete 5GHz sample of Kuehr et al. (1981, Cat. <VIII/5>). The high frequency (5-18.5GHz) spectral indices of steep-spectrum sources for which we have 18.5GHz data (66% of the complete sample) are systematically steeper than the low frequency (2.7-5GHz) ones, and there is evidence of an anti-correlation of high-frequency spectral index with luminosity. The completeness of 18.5GHz data is much higher (89%) for flat-spectrum sources (mostly quasars), which also exhibit a spectral steepening. Taking advantage of the almost complete redshift information on flat-spectrum quasars, we have estimated their 5GHz luminosity function in several redshift bins. The results confirm that their radio luminosity density peaks at z_peak about 2.5 but do not provide evidence for deviations from pure luminosity evolution as hinted at by other data sets. A comparison of our 22GHz flux densities with WMAP K-band data for flat-spectrum sources suggests that WMAP flux densities may be low by a median factor of about 1.2. The extrapolations of 5GHz counts and luminosity functions of flat-spectrum radio quasars using the observed distribution of the 5-18.5GHz spectral indices match those derived directly from WMAP data, indicating that the high frequency WMAP survey does not detect any large population of FSRQs with anomalous spectra.
- ID:
- ivo://CDS.VizieR/J/MNRAS/354/305
- Title:
- ATCA 18GHz pilot survey first results
- Short Name:
- J/MNRAS/354/305
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a pilot study for the first all-sky radio survey at short wavelengths, we have observed 1216deg^2^ of the southern sky at 18GHz (16mm) using a novel wide-band (3.4-GHz bandwidth) analogue correlator on one baseline of the Australia Telescope Compact Array. We scanned a region of sky between declination -71{deg} and -59{deg} with an rms noise level of 15mJy. Follow-up radio imaging of candidate sources above a 4{sigma} detection limit of 60mJy resulted in 221 confirmed detections, for which we have measured accurate positions and flux densities. For extragalactic sources, the survey is roughly 70 per cent complete at a flux density of 126mJy and 95 per cent complete above 300mJy. Almost half the detected sources lie within a few degrees of the Galactic plane, but there are 123 sources with |b|>5{deg}, which can be assumed to be extragalactic.
