- ID:
- ivo://CDS.VizieR/J/MNRAS/229/589
- Title:
- Interplanetary Scintillation Survey at 81.5 MHz
- Short Name:
- J/MNRAS/229/589
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of 1789 radio sources which exhibit interplanetary scintillation (IPS) at 81.5 MHz is presented. The angular diameters of scintillating components in the range 0.2-2 arcsec are listed together with values of the scintillating flux density at a solar elongation of 90 deg. IPS selects those sources which are highly compact, such as pulsars and some unusual extragalactic sources, or those in which energy is being released from active beams in the outer lobes of intrinsically powerful radio galaxies and quasars. The survey was made with the 3.6-hectare array at Cambridge and covers the area of sky between declinations -10 deg and +83 deg at all values of right ascension. The array was operated as a north-south phase-switching interferometer observing sources near meridian transit. Sixteen declination beams were produced covering the observed declination range. The half-power width of a declination beam is 5.5 sec(52.16-DEC) degrees, where DEC is the declination of peak beam response. The half-power beam width in right ascension is 107 sec(delta) s for a source at declination delta. The faintest sources in the catalogue have scintillating flux densities of about 0.3 Jy rms at a solar elongation of 90 deg, and total flux densities of about 5 Jy at 81.5 MHz. The sensitivity of the survey is not uniform over the sky, being determined largely by the galactic background emission. The flux density corresponding to one source per beam area in this survey is about 2.3 Jy at 81.5 MHz so that confusion errors are likely to be significant for total flux density S <= 20 Jy.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/165/439
- Title:
- Interstellar scintillation at 2 and 8GHz
- Short Name:
- J/ApJS/165/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From 1979 to 1996 the Green Bank Interferometer was used by the Naval Research Laboratory to monitor the flux density from 146 compact radio sources at frequencies near 2 and 8GHz. We filter the light curves to separate intrinsic variations on times of a year or more from more rapid interstellar scintillation (ISS) on times of 550 days. Whereas the intrinsic variation at 2GHz is similar to that at 8GHz (although diminished in amplitude), the ISS variation is much stronger at 2 than at 8GHz. We characterize the ISS variation by an rms amplitude and a timescale and examine the statistics of these parameters for the 121 sources with significant ISS at 2GHz. We model the scintillations using the NE2001 Galactic electron model assuming the sources are brightness-limited.
- ID:
- ivo://CDS.VizieR/B/iram
- Title:
- IRAM Observation Logs
- Short Name:
- B/iram
- Date:
- 04 Jan 2022 15:31:49
- Publisher:
- CDS
- Description:
- The Institut de Radio Astronomie Millimetrique (IRAM) was founded in 1979 and is operated as a French-German-Spanish collaboration. Its partner institutes are the CNRS (Centre National de la Recherche Scientifique, France), the MPG (Max Planck Gesellschaft, Germany), and the IGN (Instituto Geografico Nacional, Spain). The principal activity of IRAM is the study of cold matter (molecular gas and dust) in the solar system, in our Galaxy, and out to cosmological distances in order to determine its composition, density, mass, temperature, and kinematics. IRAM operates two observatories at millimeter wavelengths which are open to the international astronomical community: The 30-m single-dish telescope on Pico Veleta (2850m), Spain, and the six-antenna interferometer on the Plateau de Bure (2550m) in France. Both sites are at high altitude to reduce the absorption by water vapor. The observatories are supported by the IRAM offices and laboratories in Granada and Grenoble. The observation log included here concerns the Plateau de Bure site, and summarizes the observations made there from December 1990. The observations log of the 30-m single-dish telescope covers a period starting in January 2009. This log was produced using a header archive, a collaborative effort between IRAM and IAA/CSIC. NOEMA (NOrthern Extended Millimeter Array) is the successor to the Plateau du Bure observatory. During its history, the observatory at the Plateau de Bure underwent several track extensions, received additional antennas (all of 15m diameter and similar construction as the first ones) and technical upgrades. From a three antenna interferometer with a maximum baseline of 288 meters in 1988, it has evolved to a eight-antenna array with baselines up to 760 meters in 2016. With the inauguration of the seventh antenna in September 2014, the observatory has started its transformation into NOEMA.
- ID:
- ivo://CDS.VizieR/J/A+A/507/241
- Title:
- IR and 610MHz observations in MGRO J2019+37
- Short Name:
- J/A+A/507/241
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- MGROJ2019+37 is an unidentified extended source of very high energy gamma-rays originally reported by the Milagro Collaboration as the brightest TeV source in the Cygnus region. Its extended emission could be powered by either a single or several sources. The GeV pulsar AGL J2020.5+3653 discovered by AGILE and associated with PSR J2021+3651 could contribute to the emission from MGRO J2019+37. The aim of this paper is to identify radio and near-infrared sources in the field of the extended TeV source MGRO J2019+37, and study potential counterparts to explain its emission. We surveyed a region of about 6 square degrees with the Giant Metrewave Radio Telescope (GMRT) at the frequency 610MHz. We also observed the central square degree of this survey in the near-infrared Ks-band using the 3.5m telescope in Calar Alto. Archival X-ray observations of some specific fields are included. VLBI observations of an interesting radio source were performed. We explored possible scenarios to produce the multi-TeV emission from MGRO J2019+37 and studied which of the sources could be the main particle accelerator.
- ID:
- ivo://CDS.VizieR/J/A+A/544/L7
- Title:
- IRAS 16293-2422 ALMA maps
- Short Name:
- J/A+A/544/L7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We focus on the kinematical properties of a proto-binary to study the infall and rotation of gas toward its two protostellar components. We present ALMA Science Verification observations with high-spectral resolution of IRAS 16293-2422 at 220.2GHz. The wealth of molecular lines in this source and the very high spectral resolution offered by ALMA allow us to study the gas kinematics with unprecedented detail.
- ID:
- ivo://CDS.VizieR/J/A+A/299/347
- Title:
- IRAS galaxies behind Taurus clouds
- Short Name:
- J/A+A/299/347
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a complete search for IRAS galaxies in the Taurus molecular cloud region at l=169deg to 177deg and b=-19deg to -12deg. We selected a total number of 36 galaxies and galaxy candidates and looked for the 21-cm H I line in 25 objects; we detected H I emission in five of them including one with previously unknown redshift. The spatial density of IRAS galaxies with cz=4000 to 6000km/s is lower in this region than in the adjacent regions at both sides along galactic longitude, where the Perseus supercluster and the Gemini-Monoceros filament are respectively located.
- ID:
- ivo://CDS.VizieR/J/A+A/475/925
- Title:
- IRAS 05358+3543 (sub)mm maps
- Short Name:
- J/A+A/475/925
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the small-scale structure of massive star-forming regions through interferometric observations in several (sub)mm wavelength bands. We determine the kinetic temperature of the gas around the protostars, and derive the column density of several molecular species. For two of the protostars, constrains on the density are also inferred.
- ID:
- ivo://CDS.VizieR/J/other/BSAO/50.115
- Title:
- IRAS-TEXAS cross-identifications
- Short Name:
- J/other/BSAO/50.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A procedure of sampling objects by way of cross-identification of the low-frequency radio catalogue of objects obtained with the aid of the Texas interferometer at the frequency 365MHz and of the IRAS (Cat. <II/125>) catalogue is discussed. Statistical properties of different subsamples of sources are investigated. From the results of cross-identification with the radio catalogues of the database CATS (Verkhodanov et al., 1997BaltA...6..275V), continuous radio spectra of objects are plotted, identification with optical and X-ray catalogues is carried out. From the steep spectrum objects sources are selected for further studies.
- ID:
- ivo://CDS.VizieR/J/A+A/600/A87
- Title:
- IRAS17020+4544 VLBA 5, 8, 15, 24GHz images
- Short Name:
- J/A+A/600/A87
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent XMM-Newton observations have revealed that IRAS 17020+4544 is a very unusual example of black hole windproduced feedback by a moderately luminous AGN in a spiral galaxy. Since the source is known for being a radio emitter, we investigated about the presence and the properties of a non-thermal component. We observed IRAS 17020+4544 with the Very Long Baseline Array at 5, 8, 15, and 24GHz within a month of the 2014 XMM-Newton observations. We further analysed archival data taken in 2000 and 2012. Results. We detect the source at 5GHz and on short baselines at 8GHz. At 15 and 24 GHz, the source is below our baseline sensitivity for fringe fitting, indicating the lack of prominent compact features. The morphology is that of an asymmetric double, with significant diffuse emission. The spectrum between 5 and 8GHz is rather steep (S{nu}~nu^-(1.0+/-0.2)^). Our re-analysis of the archival data at 5 and 8GHz provides results consistent with the new observations, suggesting that flux density and structural variability are not important in this source. We put a limit on the separation speed between the main components of <0.06c. IRAS 17020+4544 shows interesting features of several classes of objects: its properties are typical of compact steep spectrum sources, low power compact sources, radio-emitting narrow line Seyfert 1 galaxies. However, it can not be classified in any of these categories, remaining so far a one-of-a-kind object.
- ID:
- ivo://CDS.VizieR/J/MNRAS/302/222
- Title:
- ISO ELAIS 20cm VLA survey regions
- Short Name:
- J/MNRAS/302/222
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Very Large Array (VLA) in C configuration to carry out a sensitive 20-cm radio survey of regions of the sky that have been surveyed in the far-infrared (FIR) over the wavelength range 5-200{mu}m with ISO (Infrared Space Observatory) as part of the European Large-Area ISO Survey (ELAIS). As usual in surveys based on a relatively small number of overlapping VLA pointings, the flux limit varies over the area surveyed: from a 5{sigma} limit of 0.135mJy over an area of 0.12deg^2^ to 1.15mJy or better over the whole region covered of 4.22deg^2^. In this paper we present the complete radio catalogue of 867 sources, 428 of which form a complete sample in the flux range 0.2-1.0mJy. These regions of the sky have previously been surveyed to shallower flux limits at 20cm with the VLA as part of the VLA D configuration NVSS (full width at half-maximum, FWHM=45arcsec) and VLA B configuration FIRST (FWHM=5arcsec) surveys. Our whole survey has a nominal 5{sigma} flux limit a factor of 2 below that of the NVSS; 3.4deg^2^ of the survey reaches the nominal flux limit of the FIRST survey and 1.5deg^2^ reaches 0.25mJy, a factor of 4 below the nominal FIRST survey limit. In addition, our survey is at a resolution intermediate between the two surveys and thus is well suited for a comparison of the reliability and resolution-dependent surface brightness effects that affect interferometric radio surveys. We have carried out a detailed comparison of our own survey and these two independent surveys in order to assess the reliability and completeness of each. Considering the whole sample, we found that to the 5{sigma} nominal limits of 2.3 and 1.0mJy, respectively, the NVSS and FIRST surveys have a completeness of 96^+2^_-3_ and 89^+2^_-3_ per cent and a reliability of 99^+1^_-2_ and 94^+2^_-2_ per cent.
