Search

Start Over Subject radio astronomy Rights public
1631. Studies of Bright Steep-Spectrum Radio Sources
ID:
ivo://CDS.VizieR/J/AZh/77/3
Title:
Studies of Bright Steep-Spectrum Radio Sources
Short Name:
J/AZh/77/3
Date:
21 Oct 2021
Publisher:
CDS
Description:
Results of studies of bright radio sources in the constellation Cetus are presented. More than 50% of the sources have radio spectral indices steeper than 0.9. Optical identifications have been determined for 35 sources. A large fraction of the radio sources are identified with weak blue galaxies. Given their spectral indices, it is likely that these objects have redshift z=0.4-1.0. More than 20% of the steep-spectrum sources do not have optical identifications and appear to be weak galaxies with z>2.
1632. Subaru/XMM Deep Field radio imaging. III.
ID:
ivo://CDS.VizieR/J/MNRAS/421/3060
Title:
Subaru/XMM Deep Field radio imaging. III.
Short Name:
J/MNRAS/421/3060
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectroscopic and 11-band photometric redshifts for galaxies in the 100-uJy Subaru/XMM-Newton Deep Field radio source sample. We find good agreement between our redshift distribution and that predicted by the Square Kilometre Array (SKA) Simulated Skies project. We find no correlation between K-band magnitude and radio flux, but show that sources with 1.4-GHz flux densities below ~1mJy are fainter in the near-infrared than brighter radio sources at the same redshift, and we discuss the implications of this result for spectroscopically incomplete samples where the K-z relation has been used to estimate redshifts. We use the infrared-radio correlation to separate our sample into radio-loud and radio-quiet objects and show that only radio-loud hosts have spectral energy distributions consistent with predominantly old stellar populations, although the fraction of objects displaying such properties is a decreasing function of radio luminosity.
1633. Sub-mJy radio sources complete sample
ID:
ivo://CDS.VizieR/J/PASP/113/10
Title:
Sub-mJy radio sources complete sample
Short Name:
J/PASP/113/10
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Very Large Array has been used in C configuration to map an area ~=0.3deg^2^ at 1.4GHz with 5{sigma} sensitivities of 0.305, 0.325, 0.380, and 0.450mJy/beam over four equal subareas. Radio properties are presented for 62 detected sources. Deep optical imaging to Gunn r ~=25mag using the Hale 5m telescope covering ~=0.21deg^2^ is reported for a subset of 43 sources. This optical follow-up is much deeper than that of existing larger area radio surveys of similar radio sensitivity. Archival J-, H-, and K-band photometry from the Two-Micron All Sky Survey is also presented. Using a robust likelihood ratio technique, we optically identified 26 radio sources with probability >~80%, nine with uncertain/ambiguous detections, and eight with empty fields. Comparisons with a stellar synthesis model that includes radio emission and dust reddening suggest that the near-infrared-optical emission in a small, bright subsample is reddened by "optically thin" dust with absorption A_V_~=22.5mag, regardless of morphological type. This is consistent with other, more direct determinations of absorption. The radio-optical(-near-infrared) flux ratios of early-type galaxies require significant contamination in the radio by an active galactic nucleus, consistent with the current paradigm. Using our simple modeling approach, we also discuss a potential diagnostic for selecting ultraluminous infrared galaxies to z~=1.6 from microJansky radio surveys.
1634. Sub-mJy radio sources SF properties
ID:
ivo://CDS.VizieR/J/MNRAS/453/1079
Title:
Sub-mJy radio sources SF properties
Short Name:
J/MNRAS/453/1079
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the star formation properties of ~800 sources detected in one of the deepest radio surveys at 1.4GHz. Our sample spans a wide redshift range (~0.1-4) and about four orders of magnitude in star formation rate (SFR). It includes both star-forming galaxies (SFGs) and active galactic nuclei (AGNs), further divided into radio-quiet (RQ) and radio-loud objects. We compare the SFR derived from the far-infrared luminosity, as traced by Herschel, with the SFR computed from their radio emission. We find that the radio power is a good SFR tracer not only for pure SFGs but also in the host galaxies of RQ AGNs, with no significant deviation with redshift or specific SFR. Moreover, we quantify the contribution of the starburst activity in the SFG population and the occurrence of AGNs in sources with different level of star formation. Finally, we discuss the possibility of using deep radio survey as a tool to study the cosmic star formation history.
1635. Sub-mm observations of SNR IC 443
ID:
ivo://CDS.VizieR/J/A+A/279/541
Title:
Sub-mm observations of SNR IC 443
Short Name:
J/A+A/279/541
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
1636. SUMSS Giant Radio Sources
ID:
ivo://CDS.VizieR/J/AJ/130/896
Title:
SUMSS Giant Radio Sources
Short Name:
J/AJ/130/896
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a complete sample of megaparsec-sized double radio sources compiled from the Sydney University Molonglo Sky Survey (SUMSS, Cat. <VIII/70>). Almost complete redshift information has been obtained for the sample. The sample has the following defining criteria: Galactic latitude |b|>12.5{deg}, declination {delta}<-50{deg}, and angular size >5'. All the sources have a projected linear size larger than 0.7Mpc (assuming H_0_=71km/s/Mpc). The sample is chosen from a region of the sky covering 2100{deg}^2^. In this paper we present 843MHz radio images of the extended radio morphologies made using the Molonglo Observatory Synthesis Telescope, higher resolution radio observations of any compact radio structures using the Australia Telescope Compact Array, and low-resolution optical spectra of the host galaxies from the 2.3m Australian National University telescope at Siding Spring Observatory. The sample presented here is the first in the southern hemisphere and significantly enhances the database of known giant radio sources. The giant radio sources with linear size exceeding 0.7Mpc have an abundance of (215Mpc)^-3^ at the sensitivity of the survey. In the low-redshift universe, the survey may be suggesting the possibility that giant radio sources with relict lobes are more numerous than giant sources in which beams from the center currently energize the lobes.
1637. Sunyaev-Zel'dovich galaxy clusters surveyed by ACT
ID:
ivo://CDS.VizieR/J/ApJS/253/3
Title:
Sunyaev-Zel'dovich galaxy clusters surveyed by ACT
Short Name:
J/ApJS/253/3
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a catalog of 4195 optically confirmed Sunyaev-Zel'dovich (SZ) selected galaxy clusters detected with signal-to-noise ratio >4 in 13211deg^2^ of sky surveyed by the Atacama Cosmology Telescope (ACT). Cluster candidates were selected by applying a multifrequency matched filter to 98 and 150GHz maps constructed from ACT observations obtained from 2008 to 2018 and confirmed using deep, wide-area optical surveys. The clusters span the redshift range 0.04<z<1.91 (median z=0.52). The catalog contains 222 z>1 clusters, and a total of 868 systems are new discoveries. Assuming an SZ signal versus mass-scaling relation calibrated from X-ray observations, the sample has a 90% completeness mass limit of M_500c_>3.8x10^14^M_{sun}_, evaluated at z=0.5, for clusters detected at signal-to-noise ratio >5 in maps filtered at an angular scale of 2.4'. The survey has a large overlap with deep optical weak-lensing surveys that are being used to calibrate the SZ signal mass-scaling relation, such as the Dark Energy Survey (4566deg^2^), the Hyper Suprime-Cam Subaru Strategic Program (469deg^2^), and the Kilo Degree Survey (825deg^2^). We highlight some noteworthy objects in the sample, including potentially projected systems, clusters with strong lensing features, clusters with active central galaxies or star formation, and systems of multiple clusters that may be physically associated. The cluster catalog will be a useful resource for future cosmological analyses and studying the evolution of the intracluster medium and galaxies in massive clusters over the past 10Gyr.
1638. SuperCLASS. I.
ID:
ivo://CDS.VizieR/J/MNRAS/495/1706
Title:
SuperCLASS. I.
Short Name:
J/MNRAS/495/1706
Date:
21 Oct 2021
Publisher:
CDS
Description:
The SuperCLuster Assisted Shear Survey (SuperCLASS) is a legacy programme using the e-MERLIN interferometric array. The aim is to observe the sky at L-band (1.4GHz) to a r.m.s. of 7uJy/beam over an area of 1 square degrees centred on the Abell 981 supercluster. The main scientific objectives of the project are: (i) to detect the effects of weak lensing in the radio in preparation for similar measurements that will be made by the Square Kilometre Array (SKA); (ii) an extinction free census of star formation and AGN activity at z up to 1. In this paper we give an overview of the project including the science goals and multi-wavelength coverage before presenting the first data release. We have analysed around 400 hours of e-MERLIN data which has allowed us to create a DR1 mosaic covering an area ~0.26 square degrees to the full depth. These observations have been supplemented with complementary radio observations from the Karl G. Jansky Very Large Array (VLA) and optical/near infra-red observations taken with the Subaru, Canada-France-Hawaii and Spitzer Telescopes. The main data product is a catalogue of 887 sources detected by the VLA, of which 395 are detected by e-MERLIN and 197 of these are resolved. We have investigated the size, flux and spectral index properties of these sources and find them to be compatible with previous studies. Preliminary photometric redshifts, and an assessment of galaxy shapes measured in the radio data, combined with a radio-optical cross-correlation technique to probe cosmic shear in a supercluster environment, are presented in companion papers.
1639. 2 supergiants and 2 hypergiants radio spectra
ID:
ivo://CDS.VizieR/J/A+A/545/A99
Title:
2 supergiants and 2 hypergiants radio spectra
Short Name:
J/A+A/545/A99
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present Herschel/HIFI spectra observed towards two Red Supergiants (NML Cyg, Betelgeuse) and two Yellow Hypergiants (AFGL2343, IRC+10420). The data focus on various transitions of ^12^CO, ^13^CO, ortho- and para- water, as well as some other bonus lines such as SiO, OH or NH_3_.
1640. SUPER GOODS. I. Ultradeep SCUBA-2 survey
ID:
ivo://CDS.VizieR/J/ApJ/837/139
Title:
SUPER GOODS. I. Ultradeep SCUBA-2 survey
Short Name:
J/ApJ/837/139
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this first paper in the SUPER GOODS series on powerfully star-forming galaxies in the two GOODS fields, we present a deep SCUBA-2 survey of the GOODS-N at both 850 and 450{mu}m (central rms noise of 0.28mJy and 2.6mJy, respectively). In the central region, the 850{mu}m observations cover the GOODS-N to near the confusion limit of ~1.65mJy, while over a wider 450arcmin^2^ region-well complemented by Herschel far-infrared imaging-they have a median 4{sigma} limit of 3.5mJy. We present >=4{sigma} catalogs of 186 850{mu}m and 31 450{mu}m selected sources. We use interferometric observations from the Submillimeter Array (SMA) and the Karl G. Jansky Very Large Array (VLA) to obtain precise positions for 114 SCUBA-2 sources (28 from the SMA, all of which are also VLA sources). We present new spectroscopic redshifts and include all existing spectroscopic or photometric redshifts. We also compare redshifts estimated using the 20cm/850{mu}m and the 250cm/850{mu}m flux ratios. We show that the redshift distribution increases with increasing flux, and we parameterize the dependence. We compute the star formation history and the star formation rate (SFR) density distribution functions in various redshift intervals, finding that they reach a peak at z=2-3 before dropping to higher redshifts. We show that the number density per unit volume of SFR>~500M_{sun}_/yr galaxies measured from the SCUBA-2 sample does not change much relative to that of lower SFR galaxies from UV selected samples over z=2-5, suggesting that, apart from changes in the normalization, the shape in the number density as a function of SFR is invariant over this redshift interval.