- ID:
- ivo://CDS.VizieR/J/MNRAS/439/545
- Title:
- Infrared-faint radio sources catalog
- Short Name:
- J/MNRAS/439/545
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 1317 Infrared-faint radio sources (IFRSs) that, for the first time, are reliably detected in the infrared, generated by cross-correlating the Wide-field Infrared Survey Explorer (WISE) all-sky survey with major radio surveys. Our IFRSs are brighter in both radio and infrared than the first-generation IFRSs that were undetected in the infrared by the Spitzer Space Telescope. We present the first spectroscopic redshifts of IFRSs, and find that all but one of the IFRSs with spectroscopy have z>2. We also report the first X-ray counterparts of IFRSs, and present an analysis of radio spectra and polarization, and show that they include gigahertz peaked-spectrum, compact steep-spectrum and ultra-steep-spectrum sources. These results, together with their WISE infrared colours and radio morphologies, imply that our sample of IFRSs represents a population of radio-loud active galactic nuclei at z>2. We conclude that our sample consists of lower redshift counterparts of the extreme first-generation IFRSs, suggesting that the fainter IFRSs are at even higher redshift.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/532/A127
- Title:
- Inner Galaxy HII regions
- Short Name:
- J/A+A/532/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report simultaneous H110{alpha} and H_2_CO line observations with the 25m radio telescope of Nanshan station toward 251 HII regions. We used the H110{alpha} line to establish the velocity of the HII regions and H_2_CO absorption lines to distinguish between near and far distances. We detected the H110{alpha} RRLs in 28 sources and H_2_CO absorption lines in 59 sources. In the latter case, 43 features had not previously been observed. H_2_CO and H110{alpha} lines were simultaneously detected toward 23 HII regions. We resolved the kinematic distance ambiguities for 14 HII regions and 20 intervening molecular clouds.
- ID:
- ivo://CDS.VizieR/J/ApJS/154/553
- Title:
- Inner galaxy massive star formation regions
- Short Name:
- J/ApJS/154/553
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report simultaneous H110{alpha} and H_2_CO line observations with the NRAO Green Bank Telescope toward 72HII regions in the Spitzer Space Telescope GLIMPSE survey area (|l|=10{deg}-65{deg} and |b|<=1{deg}). We used the H110{alpha} line to establish the velocity of the HII regions and H_2_CO absorption lines to distinguish between near and far distances. Accurate distances are crucial for the determination of physical properties of massive star formation regions.
- ID:
- ivo://CDS.VizieR/J/AJ/149/32
- Title:
- Integrated radio continuum spectra of galaxies
- Short Name:
- J/AJ/149/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the spectral shape of the total continuum radiation, between 74MHz and 5GHz (400-6cm in wavelength), for a large sample of bright galaxies. We take advantage of the overlapping survey coverage of the VLA Low-Frequency Sky Survey, the Westerbork Northern Sky Survey, the NRAO VLA Sky Survey, and the Green Bank 6cm Survey to achieve significantly better resolution, sensitivity, and sample size compared to prior efforts of this nature. For our sample of 250 bright galaxies we measure a mean spectral index, {alpha}, of -0.69 between 1.4 and 4.85GHz, -0.55 between 325MHz and 1.4GHz, and -0.45 between 74 and 325MHz, which amounts to a detection of curvature in the mean spectrum. The magnitude of this curvature is approximately {Delta}{alpha}=-0.2 per logarithmic frequency decade when fit with a generalized function having constant curvature. No trend in low-frequency spectral flattening versus galaxy inclination is evident in our data, suggesting that free-free absorption is not a satisfying explanation for the observed curvature. The ratio of thermal to non-thermal emission is estimated through two independent methods: (1) using the IRAS far-IR fluxes and (2) with the value of the total spectral index. Method (1) results in a distribution of 1.4GHz thermal fractions of 9%+/-3%, which is consistent with previous studies, while method (2) produces a mean 1.4GHz thermal fraction of 51% with dispersion 26%. The highly implausible values produced by method (2) indicate that the sum of typical power-law thermal and non-thermal components is not a viable model for the total spectral index between 325 and 1.4GHz. An investigation into relationships between spectral index, infrared-derived quantities, and additional source properties reveals that galaxies with high radio luminosity in our sample are found to have, on average, a flatter radio spectral index, and early types tend to have excess radio emission when compared to the radio-infrared ratio of later types. Early types also have radio emission that is more compact than later type galaxies, as compared to the optical size of the galaxy. Despite these differences, no relation between spectral index and galaxy type is detected.
- ID:
- ivo://CDS.VizieR/J/AZh/83/542
- Title:
- Integrated Radio Luminosities of Pulsars
- Short Name:
- J/AZh/83/542
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The integrated radio luminosities of 311 long-period (P>0.1s) and 27 short-period (P<0.1s) pulsars have been calculated using a new compilation of radio spectra. The luminosities are in the range 10^27^-10^30^erg/s for 88% of the long-period pulsars and 10^28^-10^31^erg/s for 88% of the short-period pulsars. We find a high correlation between the luminosity L and the estimate L1=S_(400)_*d^2^ from the catalog of Taylor et al. (1993, See Cat. <VII/189>. The factor 'eta' for transformation of the rotational energy of the neutron star into radio emission increases/decreases with increasing period for long-period/short-period pulsars. The mean value of 'eta'=-3.73 for the long-period and -4.85 for the short-period pulsars.
- ID:
- ivo://CDS.VizieR/J/AJ/77/405
- Title:
- Intense radio sources at 1400MHz (BDFL sample)
- Short Name:
- J/AJ/77/405
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate flux densities, precise positions of unresolved sources, and structures of resolved sources have been derived from full-beam and interferometric observations of intense sources at 1400 MHz. Results are given for 424 sources in the area of sky -5{deg}<{delta}<+70{deg}, |b|>5 whose 1400-MHz integrated flux densities S_1400_ exceed 1.70Jy [1 Jy (flux unit) = 10^-26^w/m^2^/Hz]. The 234 sources with S_1400_>=2.00Jy, equivalent diameters <10arcmin, and |b|>20{deg} form a 98+/-2% complete sample comparable in number to the 178-MHz Revised Third Cambridge Catalogue in this 4.30-sr area of sky, but selected at 1400MHz. This sample is suitable for statistical studies of the properties of extragalactic radio sources. To facilitate its use, and that of other samples which may be drawn from these data, references to other studies of the positions, fine and extended structure, polarization, and variability of the sources have been assembled in the principal table of this paper (Table 2). A comparison is made with other 1400-MHz flux-density data (Sec. 3), and the spectral content of the complete sample is discussed (Sec. 4).
- ID:
- ivo://CDS.VizieR/J/A+AS/146/141
- Title:
- Intensive monitoring of OJ 287
- Short Name:
- J/A+AS/146/141
- Date:
- 03 Dec 2021 00:36:11
- Publisher:
- CDS
- Description:
- We present intensive optical, infrared, and radio monitoring observations of the BL Lac object OJ 287, taken between the years 1993-1998. Two large optical outbursts were detected at the predicted times in November 1994 and December 1995. The detection of these outbursts supports the binary black hole model for OJ 287. Optical and radio polarisation observations show large variability in the degree of polarisation and position angle, very similar to those observed during the 1983/84 outburst in OJ 287. The polarisation position angles show very similar behaviour during these observations, indicating that, at least, the magnetic field orientations in radio and optical bands are related in OJ 287. Optical and infrared light curves show continuous variability in time scales ranging from tens of minutes to years. In the radio bands we have observed some of the lowest ever measured flux levels. During the first optical outburst in November 1994 the observed radio flux was very low, but during the second optical outburst radio bands also showed high flux levels. This is a puzzling observation, which can hopefully be used for discriminating between different outburst models. On top of the large outbursts OJ 287 has displayed flaring activity in time scales from days to weeks and shorter time scale flickering.
- ID:
- ivo://CDS.VizieR/VIII/60
- Title:
- Interferometer phase calibration sources
- Short Name:
- VIII/60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue contains compact radio sources with accurate positions observed with the Very Large Array (VLA). These sources are primarily intended for use as phase calibration sources for the Multi-Element Radio Linked Interferometer Network (MERLIN); the sources are also suitable as phase calibrators for the VLA and can be considered as candidate phase calibrators for very long-baseline interferometry (VLBI) networks. The accuracy of the position is 12 mas for sources in Paper I, 14 mas for sources in Paper II, and 55 mas for sources in Paper III.
- ID:
- ivo://CDS.VizieR/J/A+A/482/179
- Title:
- Interferometric study of SgrB2(N)
- Short Name:
- J/A+A/482/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Amino acids are building blocks of proteins and therefore key ingredients for the origin of life. The simplest amino acid, glycine (NH2CH2COOH), has long been searched for in the interstellar medium but has not been unambiguously detected so far. At the same time, more and more complex molecules have been newly found toward the prolific Galactic center source Sagittarius B2. Since the search for glycine has turned out to be extremely difficult, we aimed at detecting a chemically related species (possibly a direct precursor), amino acetonitrile (NH_2_CH_2_CN). With the IRAM 30m telescope we carried out a complete line survey of the hot core regions Sgr B2(N) and (M) in the 3mm range, plus partial surveys at 2 and 1.3mm. We analyzed our 30m line survey in the LTE approximation and modeled the emission of all known molecules simultaneously. We identified spectral features at the frequencies predicted for amino acetonitrile lines having intensities compatible with a unique rotation temperature. We also used the Very Large Array to look for cold, extended emission from amino acetonitrile.
- ID:
- ivo://CDS.VizieR/J/AJ/131/1501
- Title:
- Intermediate-velocity clouds in the CGPS
- Short Name:
- J/AJ/131/1501
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations of intermediate-velocity clouds (IVCs) found at positive velocities in the Canadian Galactic Plane Survey Phase I region (74{deg}<l<148{deg},-3.5{deg}<b<+5.6{deg}). A catalog of 138 distinct IVCs and 13 IVC complexes has been compiled.
