- ID:
- ivo://CDS.VizieR/J/ApJS/117/319
- Title:
- Northern RASS X-ray sources catalog
- Short Name:
- J/ApJS/117/319
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of optical identifications of a representative sample of northern ({delta})>-9{deg}) ROSAT All-Sky Survey (RASS) sources. A full identification has been carried out for a count-rate- and area-limited complete RASS subsample comprising 674 sources. All sources are within six study areas outside the galactic plane (|b|>19.6{deg}), one area being near the north Galactic pole and one near the north ecliptic pole.
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- ID:
- ivo://CDS.VizieR/J/AJ/77/797
- Title:
- NRAO 5GHz Strong Source Survey
- Short Name:
- J/AJ/77/797
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 140-ft telescope at the National Radio Astronomy Observatory has been used to extend the 5-GHz strong source (S) survey over an area of 1.14 steradian. Some 240 sources have been detected in this region, of which 135 are above the completeness limit of 0.6f.u. The distribution of spectral indices for sources above the completeness limit is much broader than for samples selected from long-wavelength surveys, owing to an increase in the fraction of compact sources with flat spectra. For about half of the sources selected at 6 cm, the spectral index {alpha}>-0.5. Analysis of the dependence of the spectral index on the flux density shows that, as expected from the 408-MHz number counts and spectral index distribution, at 5 GHz there are fewer flat spectra among the weak sources than among the stronger ones. The spectral index distributions for the identified galaxies and quasars show the familiar forms: the galaxies have a strong concentration near {alpha}=-0.8 with a small tail extending toward flat spectra. The quasars show a much broader distribution of indices, but the fraction (80%) of quasars having flat spectra ({alpha}>-0.5) is much greater than that found in the low-frequency surveys. The number-flux density relation for various groups of sources selected from the 5-GHz survey show that the anomalously steep slope is confined to (a) unidentified sources, (b) sources with steep spectra ({alpha}<-0.5), and (c) sources located in the north galactic hemisphere. Sources identified with radio galaxies or quasars, or which have flat spectra, or which are in the south galactic hemisphere all show a number-flux density slope near -1.5.
- ID:
- ivo://CDS.VizieR/J/other/A+C/25.176
- Title:
- NVSS and FIRST variable sources
- Short Name:
- J/other/A+C/25.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the present study we have cross-correlated NVSS and FIRST radio catalogues having radio flux measurements at the same 1.4GHz frequency. This way we benefit from repeated observations from both catalogues, as they give more accurate positions and fluxes and more important, reveal large differences between the two measured fluxes, thus allowing to establish radio variability. As a result 79382 radio variables have been revealed, including 6301 with flux differences at 1.4GHz larger than 15mJy, 1917 with flux differences 45mJy and 260 with flux differences 200mJy. By using a special technique (Mickaelian & Sinamyan 2010 (J/MNRAS/407/681) Mickaelian+ 2011 (J/MNRAS/415/1061)), 2425 optically variable objects out of 6301 radio sources have been revealed. 2425 radio sources with both high radio and optical variability into four categories have been divided. 1206 (19%) out of 6301 radio sources have activity types from available catalogues and 619 (25.5%) out of 2425 radio sources with at the same time radio and optical variability have activity types from available catalogues. In addition, 279 radio sources out of 2425 have high variability in optical range. We have established their activity types when available. The IR fluxes and colours for the 6301 variable radio sources have been studied. Colour-colour diagrams show that most of the "unknown" sources are galaxies. The activity types for 110 (42%) out of 260 extremely high variable radio sources also have been retrieved.
- ID:
- ivo://CDS.VizieR/J/AZh/71/352
- Title:
- Objects of 1988 Zenith Sky Survey
- Short Name:
- J/AZh/71/352
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The results of optical identification of radio sources Zenith Sky Survey with the Palomar Sky Survey prints are presented. The sky survey was conducted with a RATAN-600 radio telescope at 8.0cm in a ring-aperture operation mode. All the objects belong to the radio source population with flux densities in a range from 5 to 50mJy. The mean value of the spectral index distribution for the sources identified with other catalogs was found to be equal to -0.9 at 8.0cm.
- ID:
- ivo://CDS.VizieR/J/ApJ/810/85
- Title:
- Observation of first Fermi-LAT sources at Parkes
- Short Name:
- J/ApJ/810/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In a search with the Parkes radio telescope of 56 unidentified Fermi-Large Area Telescope (LAT) gamma-ray sources, we have detected 11 millisecond pulsars (MSPs), 10 of them discoveries, of which five were reported by Kerr et al (2012ApJ...748L...2K). We did not detect radio pulsations from six other pulsars now known in these sources. We describe the completed survey, which included multiple observations of many targets conducted to minimize the impact of interstellar scintillation, acceleration effects in binary systems, and eclipses. We consider that 23 of the 39 remaining sources may still be viable pulsar candidates. We present timing solutions and polarimetry for five of the MSPs and gamma-ray pulsations for PSR J1903-7051 (pulsations for five others were reported in the second Fermi-LAT catalog of gamma-ray pulsars). Two of the new MSPs are isolated and five are in >1 day circular orbits with 0.2-0.3 M_{sun}_ presumed white dwarf companions. PSR J0955-6150, in a 24 day orbit with a 0.2-0.3 M_{sun}_ companion but eccentricity of 0.11, belongs to a recently identified class of eccentric MSPs. PSR J1036-8317 is in an 8 hr binary with a>0.14 M_{sun}_ companion that is probably a white dwarf. PSR J1946-5403 is in a 3 hr orbit with a>0.02 M_{sun}_ companion with no evidence of radio eclipses.
- ID:
- ivo://CDS.VizieR/J/A+A/489/49
- Title:
- Observations of candidate GPS sources
- Short Name:
- J/A+A/489/49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gigahertz-Peaked Spectrum (GPS) sources are likely the precursors of local radio galaxies. Existing GPS source samples are small (<200). We aim to extend the available sample of the Gigahertz-Peaked Spectrum (GPS) and High Frequency Peaker (HFP) sources in order to study their nature with greater detail and higher statistical significance.
- ID:
- ivo://CDS.VizieR/J/AJ/98/419
- Title:
- Observed quantities from B3 sources
- Short Name:
- J/AJ/98/419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains results of a large program of optical identifications of radio sources from the Third Bologna (B3) Catalog (Ficarra et al., 1985A&AS...59..255F, Cat.<VIII/37>). A homogeneous sample of 1103 radio sources, selected from the B3 catalog at 408 MHz and covering a flux density range from 2.0 to 0.1 Jy, has been mapped at 1465 MHz using the VLA at 15" resolution. Both positional and structural information have been derived and are presented here. Optical identifications have been attempted for all of the sources within the range of right ascension studied, using the Palomar Sky Survey prints, resulting in 354 proposed identifications. The RA range was restricted to exclude sky areas at low galactic latitude, because obscuration makes these unsuitable for optical identifications, and confusion makes them unsuitable for VLA snapshot-mode observations. Thus the samples were selected only from the RA intervals 23h-3h, 7h-15h. The number of rows of this table (1474) is larger than the number of sources (1103) because each radio component of multiple sources is listed as a separate line.
- ID:
- ivo://CDS.VizieR/J/A+A/394/975
- Title:
- OH 5-cm line survey in late-type stars
- Short Name:
- J/A+A/394/975
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have undertaken a comprehensive search for 5-cm excited OH maser emission from evolved stars representative of various stages of late stellar evolution. Observed sources were selected from known 18-cm OH sources. This survey was conducted with the 100-m Effelsberg telescope, at 6.0GHz in Sep 2000, to achieve high signal to noise ratio observations and a sensitivity limit of about 0.05 to 0.1Jy. A total of 65 stellar sources were searched for both main line and satellite line emission. We confirm the previous detection of 5 cm OH in Vy 2-2, do not confirm emission from NML-Cyg and do not report any other new detection within the above sensitivity limit. The number of observed sources is 67.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A90
- Title:
- OH maser emission in THOR survey
- Short Name:
- J/A+A/628/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- OH masers trace diverse physical processes, from the expanding envelopes around evolved stars to star-forming regions or supernovae remnants. Providing a survey of the ground-state OH maser transitions in the northern hemisphere inner Milky Way facilitates the study of a broad range of scientific topics. We want to identify the ground-state OH masers at 18 cm wavelength in the area covered by "The HI/OH/Recombination line survey of the Milky Way (THOR)". We will present a catalogue of all OH maser features and their possible associated environments. The THOR survey covers longitude and latitude ranges of 14.3{deg}<l<66.8{deg} and b<+/-1.25{deg}. All OH ground state lines ^2^{PI}_3/2_(J=3/2) at 1612 (F=1-2), 1665 (F=1-1), 1667 (F=2-2) and 1720MHz (F=2-1) have been observed, employing the Very Large Array (VLA) in its C configuration. The spatial resolution of the data varies between 12.5" and 19", the spectral resolution is 1.5km/s, and the rms sensitivity of the data is 10mJy/beam per channel. We identify 1585 individual maser spots (corresponding to single spectral features) distributed over 807 maser sites (regions of size ~10^3^-10^4^AU). Based on different criteria from spectral profiles to literature comparison, we try to associate the maser sites with astrophysical source types. Approximately 51% of the sites exhibit the double-horned 1612MHz spectra typically emitted from the expanding shells of evolved stars. The separations of the two main velocity features of the expanding shells typically vary between 22 and 38km/s. In addition to this, at least 20% of the maser sites are associated with star-forming regions. While the largest fraction of 1720MHz maser spots (21 out of 53) is associated with supernova remnants, a significant fraction of the 1720MHz maser spots (17) are also associated with star-forming regions. We present comparisons to the thermal ^13^CO(1-0) emission as well as to other surveys of class II CH_3_OH and H_2_O maser emission. The catalogue attempts to present associations to astrophysical sources where available, and the full catalogue is available in electronic form. This OH maser catalogue presents a unique resource of stellar and interstellar masers in the northern hemisphere. It provides the basis for a diverse range of follow-up studies from envelopes around evolved stars to star-forming regions and Supernova remnants.
- ID:
- ivo://CDS.VizieR/J/AJ/124/100
- Title:
- OH megamasers at z>0.1. III
- Short Name:
- J/AJ/124/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the final results from the Arecibo Observatory OH megamaser survey. We discuss in detail the properties of the remaining 18 OH megamasers detected in the survey, including three redetections. We place upper limits on the OH emission from 85 nondetections and examine the properties of 25 ambiguous cases for which the presence or absence of OH emission could not be determined. The complete survey has discovered 50 new OH megamasers (OHMs) in (ultra)luminous infrared galaxies ([U]LIRGs), which doubles the sample of known OHMs and increases the sample at z>0.1 sevenfold.
