- ID:
- ivo://CDS.VizieR/J/ApJS/184/1
- Title:
- Molecular clouds in the LMC by NANTEN. II.
- Short Name:
- J/ApJS/184/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied star formation activities in the molecular clouds in the Large Magellanic Cloud. We have utilized the second catalog of 272 molecular clouds obtained by NANTEN (4m radio telescope of Nagoya University at Las Campanas Observatory, Chile) to compare the cloud distribution with signatures of massive star formation including stellar clusters, and optical and radio HII regions. We find that the molecular clouds are classified into three types according to the activities of massive star formation: Type I shows no signature of massive star formation; Type II is associated with relatively small HII region(s); and Type III with both HII region(s) and young stellar cluster(s). The radio continuum sources were used to confirm that Type I giant molecular clouds (GMCs) do not host optically hidden HII regions. These signatures of massive star formation show a good spatial correlation with the molecular clouds in the sense that they are located within ~100pc of the molecular clouds.
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- ID:
- ivo://CDS.VizieR/J/A+AS/144/441
- Title:
- Molecular clouds SO and CS obs. I.
- Short Name:
- J/A+AS/144/441
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the article we present a rather extensive mapping survey of 19 molecular clouds in the SO(3_2_-2_1_) and CS(2-1) molecular lines and, at certain positions, also the corresponding 34S isotope lines. Here we present the maps of the survey.
- ID:
- ivo://CDS.VizieR/J/A+A/358/257
- Title:
- Molecular clouds SO and CS obs. II.
- Short Name:
- J/A+A/358/257
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We here analyse the observational SO and CS data presented in Nilsson et al. (2000A&AS..144..441N). The SO/CS integrated intensity ratio maps are presented for 19 molecular clouds, together with tables of relevant ratios at strategic positions, where w e have also observed ^34^SO and/or C^34^S.
- ID:
- ivo://CDS.VizieR/VIII/46
- Title:
- Molonglo deep sky survey of radio sources
- Short Name:
- VIII/46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observations for the MDS1 were made in Sep. 1973 over a period of 16 days, and consist of drift scans with the telescope set to one declination number (-20 and -62{deg}) during the transit of the RA range of the survey, and scanning a long narrow strip of sky. The MDS2 results from observations made in 1978 with the same telescope working at its maximum sensitivity
- ID:
- ivo://CDS.VizieR/VIII/16
- Title:
- Molonglo Reference Catalogue of Radio Sources
- Short Name:
- VIII/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- "408-MHz survey observations made with the Molonglo Radio Telescope have been used to prepare a catalogue of 12 141 discrete sources of listed flux density >= 0.7 Jy. The survey covers 7.85 sr of the sky defined by +18.5 (deg) >= dec(1950) >= -85.0 (deg), mod(b) >= 3 (deg). A few sources beyond the declination limits are also included. The catalogue comprises celestial coordinates with standard error typically lying between 3 and 10 arcsec and 408-MHz flux densities with standard error typically lying between 4 and 10 per cent. Galactic coordinates, notes on source morphology and cross-references to the Parkes Catalogues are included. The overall source density is 1500/sr, corresponding to 0.001 per beam area. There are 7347 sources of listed flux density >= 1.00 Jy, at which level the catalogue is substantially complete. The reliability is believed to be better than 99.9 per cent." The MRC was re-issued in 1990 with the original B1950 coordinates supplemented by J2000 values, and an additional cross-reference flag `J' added to denote (extended) sources imaged at 843-MHz by P.A. Jones. No other alterations were made to the original release. The MRC is now available on 5.25 inch, 1.2 Mbyte MS-DOS (IBM) floppy disk (0.5 inch magnetic tape is also available, but is not the preferred medium). In the floppy disk format, simple software is provided to facilitate use of the catalogue on a PC computer.
- ID:
- ivo://CDS.VizieR/J/ApJS/136/265
- Title:
- Monitoring compact radio sources at 2.5 + 8.2GHz
- Short Name:
- J/ApJS/136/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present light curves for 149 sources monitored with the Green Bank Interferometer. The light curves are at two radio frequencies (approximately 2.5 and 8.2GHz) and range from 3 to 15yr in length, covering the interval 1979-1996, and have a typical sampling of one flux density measurement every 2 days. Observations were made on a 2.4km baseline. Dual circular polarization was recorded over a 35MHz bandwidth at two frequencies in the S and X frequency bands. Until 1989 August (1989.7), the frequencies were 2.7GHz (S band) and 8.1GHz (X band); in 1989 September cryogenic receivers were installed, and the frequencies changed to 2.25GHz (S band) and 8.3GHz (X band).
- ID:
- ivo://CDS.VizieR/J/A+A/545/A117
- Title:
- Monitoring of Mrk 421 at 15 and 24 GHz
- Short Name:
- J/A+A/545/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution radio observations are ideal for constraining the value of physical parameters in the inner regions of active-galactic-nucleus jets and complement results on multiwavelength (MWL) observations. This study is part of a wider multifrequency campaign targeting the nearby TeV blazar Markarian 421 (z=0.031), with observations in the sub-mm (SMA), optical/IR (GASP), UV/X-ray (Swift, RXTE, MAXI), and {gamma} rays (Fermi-LAT, MAGIC, VERITAS). We investigate the jet's morphology and any proper motions, and the time evolution of physical parameters such as flux densities and spectral index. The aim of our wider multifrequency campaign is to try to shed light on questions such as the nature of the radiating particles, the connection between the radio and {gamma}-ray emission, the location of the emitting regions and the origin of the flux variability.
- ID:
- ivo://CDS.VizieR/J/AJ/140/533
- Title:
- Morphologies of selected AGN
- Short Name:
- J/AJ/140/533
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the optical morphologies of candidate active galaxies identified at radio, X-ray, and mid-infrared wavelengths. We use the Advanced Camera for Surveys General Catalog (ACS-GC) to identify 372, 1360, and 1238 active galactic nucleus (AGN) host galaxies from Very Large Array, XMM-Newton, and Spitzer Space Telescope observations of the COSMOS field, respectively. We investigate both quantitative (GALFIT) and qualitative (visual) morphologies of these AGN host galaxies, split by brightness in their selection band.
- ID:
- ivo://CDS.VizieR/J/ApJS/194/31
- Title:
- Morphology for groups in the FIRST database
- Short Name:
- J/ApJS/194/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The morphology of selected groups of sources in the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) survey and catalog is examined. Sources in the FIRST catalog (2003 April release, 811117 entries) were sorted into singles, doubles, triples, and groups of higher-count membership based on a proximity criteria. The 7106 groups with four or more components were examined individually for bent types including, but not limited to, wide-angle tail and narrow-angle tail types. In the process of this examination, ring, double-double, X-shaped, hybrid morphology, giant radio sources, and the herein described W-shaped and tri-axial morphology systems were also identified. For the convenience of the reader separate tables for distinctive types were generated. A few curiosities were found. For the 16950 three-component groups and 74788 two-component groups, catalogs with probability estimates for bent classification, as determined by pattern recognition techniques, are presented.
- ID:
- ivo://CDS.VizieR/J/A+A/571/A61
- Title:
- M31 polarization & magnetic structure
- Short Name:
- J/A+A/571/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Andromeda Galaxy (M31) is the nearest grand-design spiral galaxy. Thus far, most studies in the radio regime concentrated on the 10kpc ring. The central region of M31 has significantly different properties than the outer parts: The star formation rate is low, and inclination and position angle are largely different from the outer disk. The existing model of the magnetic field in the radial range 6<=r<=14kpc is extended to the innermost part r<=0.5kpc to ultimately achieve a picture of the entire magnetic field in M 31. We combined observations taken with the VLA at 3.6cm and 6.2cm with data from the Effelsberg 100-m telescope to fill the missing spacings of the synthesis data. The resulting polarization maps were averaged in sectors to analyse the azimuthal behaviour of the polarized intensity (PI), rotation measure (RM), and apparent pitch angle ({phi}_obs_). We developed a simplified 3D model for the magnetic field in the central region to explain the azimuthal behaviour of the three observables. Our 3D model of a quadrupolar or dipolar dynamo field can explain the observed patterns in PI, RM, and {phi}_obs_, while a 2D configuration is not sufficient to explain the azimuthal behaviour. In addition and independent of our model, the RM pattern shows that the spiral magnetic field in the inner 0.5kpc points outward, which is opposite to that in the outer disk, and has a pitch angle of =~33{deg}, which is much larger than that of 8{deg}-19{deg} in the outer disk. The physical conditions in the central region differ significantly from those in the 10kpc ring. In addition, the orientation of this region with respect to the outer disk is completely different. The opposite magnetic field directions suggest that the central region is decoupled from the outer disk, and we propose that an independent dynamo is active in the central region.
