- ID:
- ivo://CDS.VizieR/J/AJ/142/89
- Title:
- Precise astrometry with VLBA (VIPS)
- Short Name:
- J/AJ/142/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present accurate positions for 857 sources derived from the astrometric analysis of 16 eleven-hour experiments from the Very Long Baseline Array imaging and polarimetry survey at 5GHz (VIPS). Among the observed sources, positions of 430 objects were not previously determined at milliarcsecond-level accuracy. For 95% of the sources the uncertainty of their positions ranges from 0.3 to 0.9mas, with a median value of 0.5mas. This estimate of accuracy is substantiated by the comparison of positions of 386 sources that were previously observed in astrometric programs simultaneously at 2.3/8.6GHz. Surprisingly, the ionosphere contribution to group delay was adequately modeled with the use of the total electron content maps derived from GPS observations and only marginally affected estimates of source coordinates.
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- ID:
- ivo://CDS.VizieR/J/other/PASA/26.454
- Title:
- Precise positions of methanol masers
- Short Name:
- J/other/PASA/26.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Australia Telescope Compact Array (ATCA) has been used to determine positions for many southern methanol maser sites, with accuracy better than 1 arcsec. The results are presented here as a catalogue of more than 350 distinct sites, some of them new discoveries, and many others with positional precision 10-times better than existing published values. Clusters of 2 or 3 sites are occasionally found to account for single previously listed sources. This in turn reveals that the velocity range for each individual site is sometimes smaller than that of the originally tabulated (blended) source. Only a handful of examples then remain with a velocity range of more than 16km/s at a single compact (less than 2 arcsec) site. The precise methanol positions now allow apparent coincidences with OH masers to be confidently accepted or rejected; this has led to the important conclusion that, where a 1665-MHz OH maser lies in a massive star formation region, at more than 80 percent of the OH sites there is a precisely coincident methanol maser. The methanol precision achieved here will also allow clear comparisons with likely associated IR sources when the next generation of far-IR surveys produce precise positions.
- ID:
- ivo://CDS.VizieR/I/151
- Title:
- Precise Radio Source Positions from Mark III VLBI
- Short Name:
- I/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains observations from 600 Mark III VLBI experiments from conducted between 1979 to 1988. These experiments resulted in 237681 acceptable pairs of group delay and phase delay rate observations. These have been used to derive positions of 182 extra-galactic radio sources with typical formal standard errors less than 1 mas. The right ascension zero point of this reference frame has been aligned with the FK5 by using the optical positions of 28 extragalactic radio sources whose positions are on the FK5 system. Also included are the Mark III VLBI stations and a summary of the analysis configuration.
- ID:
- ivo://CDS.VizieR/J/A+A/475/359
- Title:
- Predicting radio fluxes of extrasolar planets
- Short Name:
- J/A+A/475/359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Close-in giant extrasolar planets ("Hot Jupiters") are believed to be strong emitters in the decametric radio range. We present the expected characteristics of the low-frequency magnetospheric radio emission of all currently known extrasolar planets, including the maximum emission frequency and the expected radio flux. We also discuss the escape of exoplanetary radio emission from the vicinity of its source, which imposes additional constraints on detectability. We compare the different predictions obtained with all four existing analytical models for all currently known exoplanets. We also take care to use realistic values for all input parameters.
- ID:
- ivo://CDS.VizieR/J/ApJ/899/159
- Title:
- Properties of 10 galaxies with Chandra
- Short Name:
- J/ApJ/899/159
- Date:
- 11 Mar 2022 14:27:52
- Publisher:
- CDS
- Description:
- We present an archival analysis of Chandra X-ray observations for 12 nearby early-type galaxies hosting radio sources with radio power >1023W/Hz at 1.4GHz, similar to the radio power of the radio source in NGC4261. Previously, in a similar analysis of eight nearby X-ray and optically bright elliptical galaxies, Werner et al. found that NGC4261 exhibited unusually low central gas entropy compared to the full sample. In the central 0.3kpc of NGC4261, the ratio of cooling time to freefall time (tcool/tff) is less than 10, indicating that cold clouds may be precipitating out of the hot ambient medium and providing fuel for accretion in the central region. NGC4261 also hosts the most powerful radio source in the original sample. Because NGC4261 may represent an important phase during which powerful feedback from a central active galactic nucleus (AGN) is fueled by multiphase condensation in the central kiloparsec, we searched the Chandra archive for analogs to NGC4261. We present entropy profiles of those galaxies, as well as profiles of tcool/tff. We find that one of them, IC4296, exhibits properties similar to NGC4261, including the presence of only single-phase gas outside of r~2kpc and a similar central velocity dispersion. We compare the properties of NGC4261 and IC4296 to hydrodynamic simulations of AGN feedback fueled by precipitation. Over the course of those simulations, the single-phase galaxy has an entropy gradient that remains similar to the entropy profiles inferred from our observations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/497/2163
- Title:
- Properties of galaxy group sample
- Short Name:
- J/MNRAS/497/2163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our understanding of how active galactic nucleus feedback operates in galaxy clusters has improved in recent years owing to large efforts in multiwavelength observations and hydrodynamical simulations. However, it is much less clear how feedback operates in galaxy groups, which have shallower gravitational potentials. In this work, using very deep Very Large Array and new MeerKAT observations from the MIGHTEE survey, we compiled a sample of 247 X-ray selected galaxy groups detected in the COSMOS field. We have studied the relation between the X-ray emission of the intra-group medium and the 1.4GHz radio emission of the central radio galaxy. For comparison, we have also built a control sample of 142 galaxy clusters using ROSAT and NVSS data. We find that clusters and groups follow the same correlation between X-ray and radio emission. Large radio galaxies hosted in the centres of groups and merging clusters increase the scatter of the distribution. Using statistical tests and Monte Carlo simulations, we show that the correlation is not dominated by biases or selection effects. We also find that galaxy groups are more likely than clusters to host large radio galaxies, perhaps owing to the lower ambient gas density or a more efficient accretion mode. In these groups, radiative cooling of the intra-cluster medium could be less suppressed by active galactic nucleus heating. We conclude that the feedback processes that operate in galaxy clusters are also effective in groups.
- ID:
- ivo://CDS.VizieR/J/AJ/162/21
- Title:
- PS1 photometry of 2863 ICRF3 quasars
- Short Name:
- J/AJ/162/21
- Date:
- 14 Mar 2022 06:53:33
- Publisher:
- CDS
- Description:
- We make use of individual (epoch) detection data from the Pan-STARRS "3{pi}" survey for 2863 optical ICRF3 counterparts in the five wavelength bands g, r, i, z, and y, published as part of the Data Release 2. A dedicated method based on the Functional Principal Component Analysis is developed for these sparse and irregularly sampled data. With certain regularization and normalization constraints, it allows us to obtain uniform and compatible estimates of the variability amplitudes and average magnitudes between the passbands and objects. We find that the starting assumption of affinity of the light curves for a given object at different wavelengths is violated for several percent of the sample. The distributions of rms variability amplitudes are strongly skewed toward small values, peaking at ~0.1mag with tails stretching to 2mag. Statistically, the lowest variability is found for the r band and the largest for the reddest y band. A small "brighter-redder" effect is present, with amplitudes in y greater than amplitudes in g in 57% of the sample. The variability versus redshift dependence shows a strong decline with z toward redshift 3, which we interpret as the time dilation of the dominant time frequencies. The colors of radio-loud ICRF3 quasars are correlated with redshift in a complicated, wavy pattern governed by the emergence of brightest emission lines within the five passbands.
- ID:
- ivo://CDS.VizieR/J/A+A/631/A148
- Title:
- PSZ2 cluster candidates. II.
- Short Name:
- J/A+A/631/A148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The second legacy catalog of Planck Sunyaev-Zeldovich (SZ) sources, hereafter PSZ2, provides the largest galaxy cluster sample selected by means of the SZ signature of the clusters in a full sky survey. In order to fully characterize this PSZ2 sample for cosmological studies, all the members should be validated and the physical properties of the clusters, including mass and redshift, should be derived. However, at the time of its publication, roughly 21% of the 1653 PSZ2 members had no known counterpart at other wavelengths. Here, we present the second and last year of observations of our optical follow-up program 128-MULTIPLE-16/15B (hereafter LP15), which has been developed with the aim of validating all the unidentified PSZ2 sources in the northern sky with declinations higher than -15{deg} that have no correspondence in the first Planck catalog PSZ1. The description of the program and the first year of observations have been presented previously. The LP15 program was awarded 44 observing nights that were spread over two years with the Isaac Newton Telescope (INT), the Telescopio Nazionale Galileo (TNG), and the Gran Telescopio Canarias (GTC), all at Roque de los Muchachos Observatory (La Palma). Following the same method as described previously, we performed deep optical imaging for more than 200 sources with the INT and spectroscopy for almost 100 sources with the TNG and GTC at the end of the LP15 program. We adopted robust confirmation criteria based on velocity dispersion and richness estimates for the final classification of the new galaxy clusters as the optical counterparts of the PSZ2 detections. Here, we present the observations of the second year of LP15, as well as the final results of the program. The full LP15 sample comprises 190 previously unidentified PSZ2 sources. Of these, 106 objects were studied before, while the remaining sample (except for 6 candidates) has been completed in the second year and is discussed here. In addition to the LP15 sample, we here study 42 additional PSZ2 objects that were originally validated as real clusters because they matched a WISE or PSZ1 counterpart, but they had no measured spectroscopic redshift. In total, we confirm the optical counterparts for 81 PSZ2 sources after the full LP15 program, 55 of them with new spectroscopic information. Forty of these 81 clusters are presented in this paper. After the LP15 observational program the purity of the PSZ2 catalog has increased from 76.7% originally to 86.2%. In addition, we study the possible reasons for false detection, and we report a clear correlation between the number of unconfirmed sources and galactic thermal dust emission.
- ID:
- ivo://CDS.VizieR/I/326
- Title:
- Pulkovo Catalogue of Reference Stars around GRS
- Short Name:
- I/326
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pulkovo catalogue of reference stars inside 78 fields around galactic radio stars (Pul GRS) of northern sky from H.G. Walter's list (1990A&AS...86..357W) was created. The coordinates of 12495 stars was obtained from the photographic plates of Pulkovo Normal Astrograph (NA, 33/346), which was photographed in 1994-1999 years. Size of worked fields (radius about 20-40 angular seconds) was determined from the resolved problem and having technical resources: modern dimensions of CCD-detector. Precise astronometric coordinates of stars were intending for optical control beyond the positions of radio sources (GRS) by means of CCD-observation. The galactic radio stars can be the frames at the definition of connection between the existed ground and cosmic astronometric reference coordinate sets. Coordinate calculation was realization with used reference stars from catalogue Tycho-2 (ICRF, J2000.0). Error of a unit of weight from reduction coordinates was resulted nearly 0.12"-0.27" (at a number of reference stars were from 12 to 50). Internal precision of catalogue was obtained from 0.02 to 0.20 arcseconds at the both coordinates.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/571
- Title:
- Pulsars identified from the NRAO VLA Sky Survey
- Short Name:
- J/A+AS/136/571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table1 gives the NVSS radio sources around the positions of all known pulsars. This table was generated by searching NVSS catalog, and each row gives the closest source around one pulsar. However, not all of them are pulsars, as we discussed in our paper. If there is "?" in the Notes, we had more considerations to identify the source as a pulsar. If there is nothing or just "*" in Notes, the source is believed to be the pulsar. Table 2 lists 14 strong pulsars not detected by the NVSS, or more exactly saying, not listed in the NVSS catalog. By the courtesy of Jim Condon, we found some of these pulsars are confused by nearby strong radio sources, and most of them were really scintillating during the NVSS.
