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2991. 7C 151-MHz survey of region 9-16h 20-35deg
ID:
ivo://CDS.VizieR/J/MNRAS/282/779
Title:
7C 151-MHz survey of region 9-16h 20-35deg
Short Name:
J/MNRAS/282/779
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cambridge Low Frequency Synthesis Telescope has been used at 151 MHz to survey a region of 1393 square degrees, in the range RA 9h to 16h, Dec 20deg to 35deg, with an angular resolution of 108x108cosec(dec) arcsec^2^. The rms noise on the maps is in general ~35-55 mJy/beam but varies considerably and exceeds this in some areas. We have extracted sources with signal-to-noise ratio > 5.5, a total of 5526, and present a catalogue of their positions and flux densities.
2992. 7C: 151MHz survey of 3 regions
ID:
ivo://CDS.VizieR/J/MNRAS/298/637
Title:
7C: 151MHz survey of 3 regions
Short Name:
J/MNRAS/298/637
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cambridge Low Frequency Synthesis Telescope has been used at 151MHz to survey three regions centred at RA=10h05min, DE=53{deg}54', RA=10h42min, DE=57{deg}36' and RA=13h32min, DE=38{deg}10', each of area 7.3x7.3cosec(DE)deg^2^. The resolution is 70x70cosec(DE)arcsec^2^, and the rms noise on the maps is typically 15mJy/beam. We present positions and flux densities for 2381 sources which have signal-to-noise ratios >5.5.
2993. 1.3cm line survey toward Orion KL
ID:
ivo://CDS.VizieR/J/A+A/581/A48
Title:
1.3cm line survey toward Orion KL
Short Name:
J/A+A/581/A48
Date:
18 Nov 2021 11:23:37
Publisher:
CDS
Description:
Orion KL has served as a benchmark for spectral line searches throughout the (sub)millimeter regime. The main goal is to systematically study spectral characteristics of Orion KL in the 1.3cm band. We carried out a spectral line survey (17.9GHz to 26.2GHz) with the Effelsberg-100m telescope towards Orion KL. We find 261 spectral lines, yielding an average line density of about 32 spectral features per GHz above 3 sigma. The identified lines include 164 radio recombination lines (RRLs) and 97 molecular lines. A total of 23 molecular transitions from species known to exist in Orion KL are detected for the first time in the interstellar medium. Non-metastable ^15^NH_3_ transitions are detected in Orion KL for the first time. Based on the velocity information of detected lines and the ALMA images, the spatial origins of molecular emission are constrained and discussed. A narrow feature is found in SO_2_ (8_1,7_-7_2,6_), possibly suggesting the presence of a maser line. Column densities and fractional abundances relative to H_2_ are estimated for 12 molecules with LTE methods. Rotational diagrams of non-metastable ^14^NH_3_ transitions with J=K+1 to J=K+4 yield different results; metastable ^15^NH_3_ is found to have a higher excitation temperature than non-metastable ^15^NH_3_, indicating that they may trace different regions. Elemental and isotopic abundance ratios are estimated: ^12^C/^13^C=63+/-17, ^14^N/^15^N=100+/-51, D/H=0.0083+/-0.0045. The dispersion of the He/H ratios derived from H_alpha/He_alpha_ pairs to H_delta_/He_delta_ pairs is very small, which is consistent with theoretical predictions that the departure coefficients bn factors for hydrogen and helium are nearly identical. Based on a non-LTE code neglecting excitation by the infrared radiation field and a likelihood analysis, we find that the denser regions have lower kinetic temperature, which favors an external heating of the Hot Core.
2994. 20cm observations of deep Swire Field
ID:
ivo://CDS.VizieR/J/AJ/136/1889
Title:
20cm observations of deep Swire Field
Short Name:
J/AJ/136/1889
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results from deep radio observations taken with the Very Large Array at a center frequency of 1400MHz covering a region of the Spitzer Wide-area InfraRed Extragalactic Survey of the Spitzer Legacy survey, centered at 10:46:00, +59:01:00 (J2000). The reduction and cataloging of radio sources are described. An electronic catalog of the sources detected above 5{sigma} is also presented. The survey presented is the deepest so far in terms of the radio source density on the sky. Perhaps surprisingly, the sources down to the bottom of the catalog appear to have median angular sizes still greater than 1-arcsec, like their cousins 10-100 times stronger. The shape of the differential logN-logS counts also seems to require a correction for the finite sizes of the sources to be self-consistent. If the logN-logS normalization remains constant at the lowest flux densities, there are about six sources per square arcminute at 15uJy at 20cm. Given the finite-source size this implies that we may reach the natural confusion limit near 1uJy.
2995. 21cm observations of 452 galaxies
ID:
ivo://CDS.VizieR/J/A+A/465/71
Title:
21cm observations of 452 galaxies
Short Name:
J/A+A/465/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents 452 new 21-cm neutral hydrogen line measurements carried out with the FORT receiver of the meridian transit Nancay radiotelescope (NRT) in the period April 2003-March 2005. This observational programme is part of a larger project aiming at collecting an exhaustive and magnitude-complete HI extragalactic catalogue for Tully-Fisher applications (the so-called KLUN project, for Kinematics of the Local Universe studies, end in 2008). The whole on-line HI archive of the NRT contains today reduced HI-profiles for ~4500 spiral galaxies of declination delta >-40{deg} (http://klun.obs-nancay.fr). As an example of application, we use direct Tully-Fisher relation in three (JHK) bands in deriving distances to a large catalog of 3126 spiral galaxies distributed through the whole sky and sampling well the radial velocity range between 0 and 8000km/s. Thanks to an iterative method accounting for selection bias and smoothing effects, we show as a preliminary output a detailed and original map of the velocity field in the Local Universe.
2996. 90cm observations of the deep SWIRE field
ID:
ivo://CDS.VizieR/J/AJ/137/4846
Title:
90cm observations of the deep SWIRE field
Short Name:
J/AJ/137/4846
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present one of the deepest radio continuum surveys to date at a wavelength >~1m. The observations were taken with the VLA at 324.5MHz covering a region of the SWIRE Spitzer Legacy survey, centered at 10:46:00, +59:01:00 (J2000). The data reduction and analysis are described and an electronic catalog of the sources detected above 5{sigma} is presented. We also discuss the observed angular size distribution for the sample. Using our deeper 20cm survey of the same field, we calculate spectral indices for sources detected in both surveys.
2997. 21cm obs. of galaxies in Psc-Per Supercl.
ID:
ivo://CDS.VizieR/J/A+A/286/17
Title:
21cm obs. of galaxies in Psc-Per Supercl.
Short Name:
J/A+A/286/17
Date:
21 Oct 2021
Publisher:
CDS
Description:
This paper presents the first results of a 21cm survey of newly discovered optically selected galaxies behind the Milky Way. We present 40 radial velocities of the new galaxies and 15 velocities of UGC and MCG galaxies in a region where the well known Pisces-Perseus-Supercluster (PPScl) is supposed to be veiled by galactic extinction (80deg<~l<~110deg). Twenty-four galaxies have radial velocities between 4000 and 6000 km/s that fit to the values usually accepted for the PPScl. We could pursue this supercluster at least to b=-5 deg around l=90 deg.
2998. 5cm OH masers survey
ID:
ivo://CDS.VizieR/J/A+A/325/255
Title:
5cm OH masers survey
Short Name:
J/A+A/325/255
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have undertaken a comprehensive search for 5 cm OH masers in regions visible from Effelsberg with the 100-m telescope (i.e., those with declinations above -29^o^). Our sample is based on bright sources taken from the IRAS Point Source Catalog and/or from previous 18cm OH and H_ 2_O surveys. Among the 165 sources observed, 16 are new (15 exhibit emission and one source shows both absorption and emission). Two new absorption line sources have been tentatively detected. The general properties of the 5cm OH sources are presented and discussed. The 6035MHz line is more often detected than the 6031MHz line. Nevertheless, the latter line is frequently present, a fact that is not explained by present OH excitation models. Simple calculations tend to show that there are enough FIR photons to pump the 6035 and 6031MHz masers, and we found that the statistics of the ratio S_ radio_/S_ IR_ at 18, 5 and 6cm suggest that the maser pumping efficiency decreases with increasing OH excitation. Variability on short (months) or long (years) time-scales is a common feature in many 5 cm OH sources. We also present observations of the 6 GHz satellite lines and report, besides W3(OH), on two certain and perhaps two newly detected weak sources. Some implications on the excitation of OH are briefly discussed.
2999. 18cm OH masers VLA obs. toward 80 SFRs
ID:
ivo://CDS.VizieR/J/ApJS/256/7
Title:
18cm OH masers VLA obs. toward 80 SFRs
Short Name:
J/ApJS/256/7
Date:
18 Feb 2022 00:54:18
Publisher:
CDS
Description:
Class I methanol masers (cIMMs) and 1720MHz OH masers are believed to arise from a common collisional pumping mechanism, and both trace shocked gas regions in supernova remnants (SNRs). However, their coexistence in star formation regions (SFRs) and their association with a front of bipolar outflow (a source of shock-stimulated collisional pumping) remain unclear. To search for collisionally pumped OH(1720) masers, we conducted a Very Large Array survey of the 18cm OH masers and continuum emission toward a sample of 80 SFRs associated with 44GHz cIMMs. Main-line OH maser emission was detected in 50% of the sample, and OH(1720) maser emission was detected in 20%. Continuum emission was detected in 28% of sources. A catalog of the detected OH masers is presented. Individual OH masers are found in close proximity, and the regions of masers of different transitions are often overlapping. A typical linear projected offset between the OH(1720) and OH(1665) masers is ~0.04pc. A remarkable number of ~81% of the OH(1720) masers are associated with the continuum emission. The median separation between the targeted 44GHz cIMMs and OH(1720) masers is ~0.2pc, which is similar to reported distances between cIMMs and HII regions. The observed properties of the detected OH(1720) masers are different from those in SNRs and indicate that a nonlocal line overlap mechanism is responsible for their excitation. Thus, while both 44GHz cIMMs and OH(1720) masers trace shocked gas in SNRs, physical conditions favorable for excitation of cIMMs, but not OH(1720) masers, are present in SFRs.
3000. 20cm Radio Catalog
ID:
ivo://nasa.heasarc/north20cm
Title:
20cm Radio Catalog
Short Name:
North20cm
Date:
28 Feb 2025
Publisher:
NASA/GSFC HEASARC
Description:
The 1.4-GHz Northern Sky Catalog - Version: 4 December 1991 This is the 20-cm Northern Sky Catalog of White, R. L. and Becker, R. H. (1992, Ap.J.Supp., in press) containing 30,239 sources detected from the Condon Greenbank images taken at 1.4 GHz over the declination range of -5 degrees to 82 degrees with a flux density limit of 100 mJy. This 20 cm catalog also contains the results of a cross-correlation with catalogs at 6 and 80 cm covering the northern sky between Dec=0 degrees and 70 degrees to give the spectral indices at three frequencies for about 20,000 sources. This is a service provided by NASA HEASARC .

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