- ID:
- ivo://CDS.VizieR/J/ApJS/80/137
- Title:
- Southern Extragalactic Radio Sources
- Short Name:
- J/ApJS/80/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains a list of 384 extragalactic radio sources south of declination -30{deg} which have been imaged with the Molonglo Observatory Synthesis Telescope (MOST) at 843 MHz with a HPBW of 44" x 44" cosec(dec). The sample includes those sources noted in the Molonglo Reference Catalog (MRC) (Cat.<VIII/16>) as extended (larger than 1'), as well as those noted as multiple (within 8' of another ssource and possibly related). The sample is representative of the strong extended extragalactic radio sources of the southern sky, but is not statistically complete. Positions, flux densities, and sizes are given for all sources, and those sources which have been confirmed as extended MRC sources are flagged. In addition, optical positions, magnitudes, redshifts, and identifications are given for 201 of the sources. These data were originally published in two tables which have been merged in this version.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/457/2366
- Title:
- Southern ZOA galaxies 21cm HI-line
- Short Name:
- J/MNRAS/457/2366
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-accuracy HI profiles and linewidths are presented for inclined ((b/a)^o^<0.5) spiral galaxies in the southern Zone of Avoidance (ZOA). These galaxies define a sample for use in the determinations of peculiar velocities using the near-infrared Tully-Fisher (TF) relation. The sample is based on the 394 HI-selected galaxies from the Parkes HI Zone of Avoidance survey (HIZOA). Follow-up narrow-band Parkes HI observations were obtained in 2010 and 2015 for 290 galaxies, while for the further 104 galaxies, sufficiently high signal-to-noise (S/N) spectra were available from the original HIZOA data. All 394 spectra are reduced and parametrized in the same systematic way. Five different types of linewidth measurements were derived, and a Bayesian mixture model was used to derive conversion equations between these five widths. Of the selected and measure galaxies, 342 have adequate signal to noise (S/N>=5) for use in TF distance estimation. The average value of the S/N ratio of the sample is 14.7. We present the HI parameters for these galaxies. The sample will allow a more accurate determination of the flow field in the southern ZOA which bisects dynamically important large-scale structures such as Puppis, the Great Attractor, and the Local Void.
- ID:
- ivo://CDS.VizieR/VIII/74A
- Title:
- SPECFIND Catalog of radio continuum spectra
- Short Name:
- VIII/74A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- SPECFIND is a new tool to extract cross-identifications and radio continuum spectra from radio catalogues contained in the VIZIER database of the CDS. It is designed to handle radio surveys of very different resolutions and sensitivities. Power laws are fitted to the radio spectra, resulting in the determination of a power law slope and a zero-point. SPECFIND has been applied to 22 survey catalogues at 11 different frequencies (159 - 8400 MHz) containing a total of 3.5 million sources, leading to 757894 independent radio cross-identifications and 66866 independent radio spectra with more than two independent frequencies. The code was tested and its results validated by a comparison between the spectral indices found by SPECFIND and those determined by other authors. The determined spectral indices have an error of about +/-0.3. Negative spectral indices have smaller errors, while the error of positive spectral indices can be larger, mainly because of the occurrence of a peak in the spectrum. The code is quite rapid (less than 3 hr running time on a standard PC for 3.5 million sources) and since it is written in C, it can be run on virtually all PCs with at least 512~MB RAM. It produces an output of variable format that can be adapted easily to the purpose of the user. The results of the spectrum identification process are provided as a master table, where a spectrum is attached to each radio source. Due to the SPECFIND algorithm, different radio components of the same physical source can have somewhat different slopes and zero-points. The SPECFIND subdirectory contains the code (in C) and the data used to generate the catalogue, as well as a user manual (manual.ps). For compilation please IMPERATIVELY read the README file stored in the SPECFIND subdirectory.
- ID:
- ivo://CDS.VizieR/VIII/104
- Title:
- SPECFIND V3.0 Catalog of radio continuum spectra
- Short Name:
- VIII/104
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Many radio continuum catalogs with different sensitivity limits and spatial resolutions are published via the VizieR database. Because of the diversity of spatial resolution, the cross-identification of individual sources is complex. By assuming a power-law spectrum, the SPECFIND tool is able to handle radio surveys at different frequencies from different instruments and different resolutions. Since the former version of the SPECFIND catalog was released ten years ago, hundreds of new radio continuum catalogs have been published. We upgraded the SPECFIND tool to reach a wider frequency range, especially the lower-frequency radio regime, as well as to have better spatial sky coverage. We adapted special selection criteria to all radio tables listed in VizieR to define a final sample of new catalogs. We implemented the new catalogs into the SPECFIND tool by unifying them and then compare the results to the last version. Furthermore we present and investigate sources with spectral breaks around 1.4GHz and around 325MHz. By increasing the number of implemented SPECFIND catalogs from 115 to 204, we improve the number of resulting spectra from 107500 to 340000 and increase the number of cross-identified sources from 600000 to 1.6 million. Furthermore, we present two samples of spectral break sources. The first sample includes 3104 spectral break sources with turnover frequencies around 1.4GHz, the second sample includes 18075 spectral break sources with turnover frequencies around 325MHz. Both samples include concave sources and Gigaherz-Peaked Spectrum (GPS) or Megaherz-Peaked Spectrum (MPS) sources. The SPECFIND V3.0 catalog is a very useful resource and a powerful open access tool, reachable via VizieR. By tripling the resulting spectra and including many radio continuum surveys from the last 50 years, we provide a significantly extended catalog of cross-identified radio continuum sources. Furthermore, the SIMBAD database will be updated using the SPECFIND V3.0 catalog and will contain more radio continuum data, serving the needs of future projects.
- ID:
- ivo://CDS.VizieR/VIII/85A
- Title:
- SPECFIND V2.0 Catalog of radio continuum spectra
- Short Name:
- VIII/85A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the second release of the SPECFIND catalogue. For the radio cross-identification we included 3.76 million sources from 105 VizieR radio catalogues. The SPECFIND V2.0 catalogue contains about 107000 physical objects with associated radio spectra. With an increase of 8% of available sources with respect to the first release, we could increase the number of radio objects by 60%. The results of the spectrum identification process are provided as a master table, where a spectrum is attached to each radio source. Due to the SPECFIND algorithm, different radio sources of the same physical object can have somewhat different slopes and zero-points. We also present radio sources from positional cross-identification only taking into account the source extent and the survey resolution (overlapping beams or extents). The source flux densities were not taken into account as it was done for the SPECFINDV2.0 catalogue. In this sense, it represents the waste basket of SPECFINDV2.0.
- ID:
- ivo://CDS.VizieR/J/AJ/146/10
- Title:
- Spectroscopy of 120 emission-line ICRF2 candidates
- Short Name:
- J/AJ/146/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Continuing our program of spectroscopic observations of International Celestial Reference Frame (ICRF) sources, we present redshifts for 120 quasars and radio galaxies. Data were obtained with five telescopes: the 3.58m European Southern Observatory New Technology Telescope, the two 8.2m Gemini telescopes, the 2.5m Nordic Optical Telescope (NOT), and the 6.0m Big Azimuthal Telescope of the Special Astrophysical Observatory in Russia. The targets were selected from the International VLBI Service for Geodesy & Astrometry candidate International Celestial Reference Catalog which forms part of an observational very long baseline interferometry (VLBI) program to strengthen the celestial reference frame. We obtained spectra of the potential optical counterparts of more than 150 compact flat-spectrum radio sources, and measured redshifts of 120 emission-line objects, together with 19 BL Lac objects. These identifications add significantly to the precise radio-optical frame tie to be undertaken by Gaia, due to be launched in 2013, and to the existing data available for analyzing source proper motions over the celestial sphere. We show that the distribution of redshifts for ICRF sources is consistent with the much larger sample drawn from Faint Images of the Radio Sky at Twenty cm (FIRST) and Sloan Digital Sky Survey, implying that the ultra-compact VLBI sources are not distinguished from the overall radio-loud quasar population. In addition, we obtained NOT spectra for five radio sources from the FIRST and NRAO VLA Sky Survey catalogs, selected on the basis of their red colors, which yielded three quasars with z>4.
- ID:
- ivo://CDS.VizieR/J/A+A/658/L2
- Title:
- Spiderweb galaxy [CII] 158um spectrum
- Short Name:
- J/A+A/658/L2
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- We present the detection of [CII] 158um emission from the Spiderweb galaxy at z=2.1612 using the Atacama Pathfinder EXperiment. The line profile splits into an active galactic nucleus (AGN) and circum galactic medium (CGM) component previously identified in CO and [CI]. We find that these individual [CII] components are consistent in terms of CO and far-IR luminosity ratios with the populations of other z>~1 AGN and dusty star-forming galaxies. The CGM component dominates the [CII] emission in the 10" APEX beam. Although we do not have spatially resolved data, the close correspondence of the velocity profile with the CO(1-0) detected only on scales of tens of kiloparsecs in CO(1-0) suggests that the [CII] emission is similarly extended, reminiscent of [CII] halos recently found around z>5 galaxies. Comparing the first four ionization states of carbon, we find that the atomic [CI] emission is dominant, which increases its reliability as a molecular mass tracer. Our [CII] detection at 601.8 GHz also demonstrates the feasibility to extend the frequency range of ALMA Band 9 beyond the original specifications.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A55
- Title:
- Spiderweb galaxy 870um and 1.4GHz images
- Short Name:
- J/A+A/570/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present APEX LABOCA 870{mu}m observations of the field around the high-redshift radio galaxy MRC1138-262 at z=2.16. We detect 16 submillimeter galaxies (SMGs) in this ~140-arcmin^2^ bolometer map with flux densities in the range 3-11mJy. The raw number counts indicate a density of SMGs that is up to four times that of blank field surveys. Based on an exquisite multiwavelength database, including VLA 1.4 GHz radio and infrared observations, we investigate whether these sources are members of the protocluster structure at z=~2.2. Using Herschel PACS and SPIRE and Spitzer MIPS photometry, we derive reliable far-infrared (FIR) photometric redshifts for all sources. Follow-up VLT ISAAC and SINFONI NIR spectra confirm that four of these SMGs have redshifts of z=~2.2. We also present evidence that another SMG in this field, detected earlier at 850{mu}m, has a counterpart that exhibits H{alpha} and CO(1-0) emission at z=2.15. Including the radio galaxy and two SMGs with FIR photometric redshifts at z=2.2, we conclude that at least eight submm sources are part of the protocluster at z=2.16 associated with the radio galaxy MRC1138-262. We measure a star formation rate density SFRD~1500M_{sun}_/yr/Mpc^3^, four magnitudes higher than the global SFRD of blank fields at this redshift. Strikingly, these eight sources are concentrated within a region of 2Mpc (the typical size of clusters in the local universe) and are distributed within the filaments traced by the HAEs at z=~2.2. This concentration of massive, dusty starbursts is not centered on the submillimeter-bright radio galaxy which could support the infalling of these sources into the cluster center. Approximately half (6/11) of the SMGs that are covered by the H{alpha} imaging data are associated with HAEs, demonstrating the potential of tracing SMG counterparts with this population. To summarize, our results demonstrate that submillimeter observations may enable us to study (proto)clusters of massive, dusty starbursts.
- ID:
- ivo://CDS.VizieR/J/ApJ/769/79
- Title:
- Spitzer observations of radio-loud AGNs (CARLA)
- Short Name:
- J/ApJ/769/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the first results from the Clusters Around Radio-Loud AGN program, a Cycle 7 and 8 Spitzer Space Telescope snapshot program to investigate the environments of a large sample of obscured and unobscured luminous radio-loud active galactic nuclei (AGNs) at 1.2<z<3.2. These data, obtained for 387 fields, reach 3.6 and 4.5{mu}m depths of [3.6]_AB_=22.6 and [4.5]_AB_=22.9 at the 95% completeness level, which is two to three times fainter than L* in this redshift range. By using the color cut [3.6]-[4.5]>-0.1 (AB), which efficiently selects high-redshift (z>1.3) galaxies of all types, we identify galaxy cluster member candidates in the fields of the radio-loud AGN. The local density of these Infrared Array Camera (IRAC)-selected sources is compared to the density of similarly selected sources in blank fields. We find that 92% of the radio-loud AGN reside in environments richer than average. The majority (55%) of the radio-loud AGN fields are found to be overdense at a>=2{sigma} level; 10% are overdense at a>=5{sigma} level. A clear rise in surface density of IRAC-selected sources toward the position of the radio-loud AGN strongly supports an association of the majority of the IRAC-selected sources with the radio-loud AGN. Our results provide solid statistical evidence that radio-loud AGN are likely beacons for finding high-redshift galaxy (proto-)clusters. We investigate how environment depends on AGN type (unobscured radio-loud quasars versus obscured radio galaxies), radio luminosity and redshift, finding no correlation with either AGN type or radio luminosity. We find a decrease in density with redshift, consistent with galaxy evolution for this uniform, flux-limited survey. These results are consistent with expectations from the orientation-driven AGN unification model, at least for the high radio luminosity regimes considered in this sample.
- ID:
- ivo://CDS.VizieR/J/A+A/508/117
- Title:
- Spitzer selected starbursts at z~2
- Short Name:
- J/A+A/508/117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Wide-field Spitzer surveys allow identification of thousands of potentially high-z submillimeter galaxies (SMGs) through their bright 24um emission and their mid-IR colors. We want to determine the average properties of such z~2 Spitzer-selected SMGs by combining millimeter, radio, and infrared photometry for a representative IR-flux (lambda_rest_~8um) limited sample of SMG candidates. A complete sample of 33 sources believed to be starbursts (5.8um-peakers) was selected in the (0.5deg^2^) J1046+56 field with selection criteria F_24um>400uJy, the presence of a redshifted stellar emission peak at 5.8um, and r'_Vega_>23. The field, part of the SWIRE Lockman Hole field, benefits from very deep VLA/GMRT 20cm, 50cm, and 90cm radio data (all 33 sources are detected at 50cm), and deep 160um and 70um Spitzer data. The 33 sources, with photometric redshifts ~1.5-2.5, were observed at 1.2mm with IRAM-30m/MAMBO to an rms ~0.7-0.8mJy in most cases. Their millimeter, radio, 7-band Spitzer, and near-IR properties were jointly analyzed.
