- ID:
- ivo://CDS.VizieR/J/AZh/74/42
- Title:
- RATAN-600 radio sources spectra
- Short Name:
- J/AZh/74/42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A multifrequency deep survey of a band of sky with the declination of the source SS 433 ({delta}~5{deg}+/-20') was performed as part of the "Kholod" program on the RATAN-600 in 1987-1988. The right ascension intervals covered by the survey are 0h<{alpha}<14h and 18h<{alpha}<24h. The spectral properties of 400 sources from the RC catalog were determined for the first time by using only RATAN-600 data. The maximum in the flux density distribution for these sources at the central wavelength, {lambda}7.6cm, occurs at ~30mJy. The lower flux limits for the sample at wavelengths of 3.9, 7.6, 13.0, and 31.0cm are 16, 9, 37, and 61mJy, respectively. These observations provide the first flux estimates at 13.0 and 31.0cm for 90% of the sources. Spectra were measured for the first time for 112 sources (28%) and were revised for 90 sources (23%). The maximum in the spectral index distribution for the entire sample in the interval from {lambda}{lambda}7.6-31.0cm occurs at {alpha}=-0.86+/-0.04 (S_v_~{nu}^{alpha}^). The spectra of some 20 of the sample sources (5%) are peaked at roughly 1GHz, and about 40 spectra (10%) have low-frequency breaks. Roughly 70 sources (19%) have flat spectra ({alpha}>-0.5), and 64 (18%) have very steep spectra ({alpha}<-1.1).
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- ID:
- ivo://CDS.VizieR/J/other/BSAO/40.128
- Title:
- RATAN-600 radio sources spectra
- Short Name:
- J/other/BSAO/40.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In accordance with the program "Cold" in 1987-1988 and in 1996 deep surveys of the sky strip at the declination of the source SS 433 ({delta}~5{deg}+/-20') were made at the radio telescope RATAN-600. For the first time spectral characteristics of 400 sources from the RC catalog have been determined using only the data obtained with the RATAN-600. The maximum of the flux density distributions at the central wavelength {lambda}7.6cm is ~30mJy. The lower flux limit in the sample of the sources at the wavelengths 3.9, 7.6, 13.0, 31.0cm is 16, 9, 37, 61mJy, respectively. Spectra of 112 sources (28%) have been obtained for the first time, spectra of 90 (23%) sources have been made more accurate. For the first time the fluxes at the wavelengths 2.7, 3.9, 13.0 and 31.0cm (90% of data) have been measured. The maximum of the distribution of spectral indices for the entire sample of sources in the interval {lambda}{lambda}7.6-31.0cm falls at {alpha}=-0.86+/-0.04 (S_{nu}_{prop.to}{nu}^alpha^). About 20 (5%) sources of the sample have a maximum of radiation at a frequency of about 1GHz (GHz-Peaked-Spectrum radio sources), about 40 (10%) have a low-frequency cut off of the spectrum. About 70 (19%) sources have flat spectra ({alpha}>-0.5), 64 (18%) very steep ({alpha}<-1.1) spectra.
- ID:
- ivo://CDS.VizieR/J/other/BSAO/40.5
- Title:
- RATAN-600 RC radio sources
- Short Name:
- J/other/BSAO/40.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the RATAN-600 radio telescope for picking up the most distant objects in the Universe. As a first step, about 100 steep spectrum FRII radio galaxies (SS FRII RG) from the RATAN-600 RC catalog (Parijskij et al., 1991, Cat. <J/A+AS/87/1>; 1992A&AS...96..583P) were mapped by the VLA and identified with optical objects down to 24-25 R mag. All the VLA images and all the deep CCD images of the RC SS fields, collected up to now, are given. An updated list of calibrators with the known redshifts of the same SS FRII class RGs was compiled to estimate photometric redshifts, redshifts from angular size - redshift relations and by the radio "standard candle" method. The mean redshift of the RC SS FRII RG list happened to be greater than 2. BVRI photometry was made, and by standard model fittings we estimated "color" redshifts and the ages of stellar systems of the parent gE galaxies in 14 cases. Several objects were found in which active star formation began in the first billion years after the Big Bang. We believe that more than 10000 of such old active galaxies are available on the sky and all of them are in the range of present day optical and radio facilities.
- ID:
- ivo://CDS.VizieR/J/AZh/84/227
- Title:
- RATAN-600 Zenith-Field sky survey (RZF) catalog
- Short Name:
- J/AZh/84/227
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of radio sources detected in a deep RATAN-600 survey is presented. The catalog was obtained in the region 0h<=RA(2000.0)<=24h, Dec(2000.0)=41:30:42+/-2, at the declination of the bright radio source 3C 84. There were nine sessions of multi-wavelength observations at wavelengths lambda=1-55cm, and more than 300 daily scans were accumulated at each wavelength. This is the first stage in the reduction of an extensive database accumulated by the Cosmological Gene Project. The RATAN-600 Zenith Field (RZF) catalog was obtained at the central wavelength of 7.6cm, and contains 437 radio sources, virtually all of which have been identified with NVSS objects. Most of the flux densities for the catalog sources are above the 5 level. Noise from faint (mainly new) background sources at a level of about 0.8mJy has been detected. The minimum flux density of the catalog, 2.5mJy, is comparable to the flux-density limit of the NVSS catalog. The catalog is more than 80% complete for sources with flux densities >3mJy.
1445. RBSC-NVSS sample. I.
- ID:
- ivo://CDS.VizieR/J/ApJS/129/547
- Title:
- RBSC-NVSS sample. I.
- Short Name:
- J/ApJS/129/547
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We cross-identified the ROSAT Bright Source Catalog (RBSC, Cat. <IX/10>) and the NRAO VLA Sky Survey (NVSS, Cat. <VIII/65>) to construct the RBSC-NVSS sample of the brightest X-ray sources (>=0.1 counts/s~10^-12^erg/cm^2^/s in the 0.1-2.4keV band) that are also radio sources (S>=2.5mJy at 1.4GHz) in the 7.8sr of extragalactic sky with |b|>15{deg} and {delta}>-40{deg}. The sky density of NVSS sources is low enough that they can be reliably identified with RBSC sources having rms positional uncertainties >=10". We used the more accurate radio positions to make reliable X-ray/radio/optical identifications down to the POSS plate limits. We obtained optical spectra for many of the bright identifications lacking published redshifts. The resulting X-ray/radio sample is unique in its size (1557 objects), composition (a mixture of nearly normal galaxies, Seyfert galaxies, quasars, and clusters), and low average redshift [<z>~0.1]
- ID:
- ivo://CDS.VizieR/J/ApJ/837/45
- Title:
- 2006-2012 Rc-band & 4.8GHz obs. of AO 0235+164
- Short Name:
- J/ApJ/837/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Variability is one of the extreme observational properties of BL Lacertae objects. AO 0235+164 is a well-studied BL Lac throughout all electromagnetic wavebands. In the present work, we show its optical R-band photometric observations carried out during the period from 2006 November to 2012 December using the Ap6E CCD camera attached to the primary focus of the 70cm meniscus telescope at Abastumani Observatory, Georgia. During our monitoring period, it showed a large variation of {Delta}R=4.88mag (14.19-19.07mag) and a short timescale of {Delta}T_v_=73.5minutes. During the period of 2006 December to 2009 November, we made radio observations of the source using the 25m radio telescope at Xinjiang Astronomical Observatory. By adopting a discrete correlation function to the optical and radio observations we found that the optical variation leads a radio variation of 23.2+/-12.9days.
- ID:
- ivo://CDS.VizieR/J/other/AstBu/65.42
- Title:
- RCR (RATAN COLD REFINED) catalogue
- Short Name:
- J/other/AstBu/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use two independent methods to reduce the data of the surveys made with RATAN-600 radio telescope at 7.6cm in 1988-1999 at the declination of the SS433 source. We also reprocess the data of the "Cold" survey (1980-1981). The resulting RCR (RATAN COLD REFINED) catalogue contains the right ascensions and fluxes of objects identified with those of the NVSS catalogue in the right-ascension interval 7h<=RA<=17h. We obtain the spectra of the radio sources and determine their spectral indices at 3.94 and 0.5GHz. The spectra are based on the data from all known catalogues available from the CATS, Vizier, and NED databases, and the flux estimates inferred from the maps of the VLSS and GB6 surveys. For 245 of the 550 objects of the RCR catalogue the fluxes are known are known only at two frequencies: 3.94GHz (RCR) and 1.4GHz (NVSS). These are mostly sources with fluxes smaller than 30mJy. About 65% of these sources have flat or inverse spectra (alpha>-0.5). We analyse the reliability of the results obtained for the entire list of objects and construct the histograms of the spectral indices and fluxes of the sources. Our main conclusion is that all 10-15mJy objects found in the considered right-ascension interval were already included in the decimetre-wave catalogues.
- ID:
- ivo://CDS.VizieR/J/AZh/93/616
- Title:
- RCR sources in Plank maps
- Short Name:
- J/AZh/93/616
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Abstract-Fields of the Planck cosmic-microwave background maps in the regions of radio sources of the RCR (Ratan Cold Refined, Cat. J/other/AstBu/65.42) catalog have been studied. Using measurements from the Planck catalog, calibration curves have been plotted in order to determine the objects' luminosities. The flux densities at millimeter and submillimeter wavelengths of 83 objects with normal radio spectra have been estimated for the first time; their spectra have also been constructed, they have been optically identified, and information available in various databases has been collected. A statistical comparison with a sample of sources with steep radio spectra has been carried out. Faint, difficult to characterize microwave sources make an additional contribution to the secondary anisotropy on angular scales <7' An algorithm for selecting candidate objects with the Sunyaev-Zel'dovich effect has been proposed, based on the use of data on the radio spectral indices and the signal in cosmic-microwave background maps.
- ID:
- ivo://CDS.VizieR/J/A+A/644/A45
- Title:
- R Crt and RT Vir Medicina spectra
- Short Name:
- J/A+A/644/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Water masers emitting at a radiofrequency of 22GHz are often found in the circumstellar envelopes of evolved stars. We monitored the H_2_O maser emission of a larger sample of evolved stars of different types to study the maser properties as a function of stellar type. We wish to understand the origin and evolution of the H_2_O masers in circumstellar envelopes. In this paper, we take a closer look at R Crt and RT Vir, two nearby (<250pc) semi-regular variable stars. The findings complement our monitoring results for RX Boo and SV Peg, two other semi-regular variable stars that we have discussed in a previous paper. Within the framework of the Medicina/Effelsberg H_2_O maser monitoring programme, we observed the maser emission of R Crt and RT Vir for more than two decades with single-dish telescopes. To get insights into the distribution of maser spots in the circumstellar envelopes at different times, to get an idea of their longevity, and, where possible, to be able to link the phenomena seen in our observations to maser locations within the envelopes, we collected interferometric data for these stars, taken within the same period, from the literature. The H_2_O masers in R Crt and RT Vir exhibit brightness variations on a variety of timescales. We confirm short-time variations of individual features on timescales of months to up to 1.5 years, as seen by previous monitoring programmes. Also decade-long variations of the general brightness level, independent from individual features, were seen in both stars. These long-term variations are attributed to brightness variations occurring independently from each other in selected velocity ranges and they are independent of the optical light curve of the stars. Expected drifts in velocity of individual features are usually masked by the blending of other features with similar velocities. However, in RT Vir, we found the exceptional case of a single feature with a constant velocity over 7.5 years (<0.06km/s/yr). We attribute the long-term brightness variations to the presence of regions with higher-than-average density in the stellar wind and hosting several clouds which emit maser radiation on short timescales. These regions typically need ~20 years to cross the H_2_O maser shell, where the right conditions for exciting H_2_O masers are present. Different clouds contained in such a region all move within a narrow range of velocities, and so does their maser emission. This sometimes gives the impression of longer-living features in single-dish spectra, in spite of the short lifetimes of the individual components that lie at their origin, thus, naturally explaining the longer timescales observed. The constant velocity feature (11km/s) is likely to come from a single maser cloud, which moved through about half of RT Vir's H_2_O maser shell without changing its velocity. From this, we infer that its path was located in the outer part of the H_2_O maser shell, where RT Vir's stellar wind has, apparently, already reached its terminal outflow velocity. This conclusion is independently corroborated by the observation that the highest H_2_O maser outflow velocity in RT Vir approaches the terminal outflow velocity, as given by OH and CO observations. This is generally not observed in other semi-regular variable stars. All four stars in our study are of optical variability type SRb, indicating the absence of periodic large-amplitude variations. Therefore, any likely responses of the maser brightness to variations of the optical emission are masked by the strong short-term maser fluctuations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/1609
- Title:
- RCW 106 Giant Molecular Cloud 13CO mapping
- Short Name:
- J/MNRAS/367/1609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first paper in a series detailing the results of ^13^CO observations of a ~1{deg}^2^ region of the giant molecular cloud (GMC) complex associated with the HII region RCW 106. The ^13^CO observations are also the first stage of a multi-molecular line study of the same region. These observations were amongst the first made using the new on-the-fly mapping capability of the Australia Telescope National Facility Mopra Telescope. In the configuration used, the instrument provided a full width at half-maximum (FWHM) beam size of 33arcsec and a velocity resolution of 0.17km/s. The gas emission takes the form of a string of knots, oriented along an axis that extends from the north-west (NW) to the south-east (SE) of the field of the observations, and which is surrounded by a more extended, diffuse emission. We analyse the 2D integrated ^13^CO emission using the CLUMPFIND algorithm and identify 61 clumps. We compare the gas data in the GMC with the dust data provided by 21um Midcourse Space Experiment (MSX) and 1.2mm Swedish European Southern Observatory Submillimetre Telescope (SEST) images that we both regridded to the cell spacing of the Mopra data and smoothed to the same resolution.
