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401. CO survey toward starless cores
ID:
ivo://CDS.VizieR/J/ApJS/152/81
Title:
CO survey toward starless cores
Short Name:
J/ApJS/152/81
Date:
21 Oct 2021
Publisher:
CDS
Description:
A CO survey is undertaken toward about 80% of the starless cores in the Lee & Myers catalog that can be observed in the northern hemisphere to investigate their general observational properties such as line width and intensity, from which one can deduce their environmental physical conditions. The peak ^12^CO intensity implies a kinetic temperature close to 10K, as is already known, but for some of the cores the kinetic temperature is much higher than 10K, suggesting either that they are not really starless or that they are externally heated. We derive the ratios of peak intensities and line widths for the pairs of ^12^CO and ^13^CO lines and find a value of ~1.7 for both. The linear correlations between them are most likely to be due to clumpy structure. These data are also compared with data sets of CS 2-1 and N_2_H^+^ 1-0 lines tracing high-density regions. It is found that the peak intensity and line width of ^13^CO are roughly correlated with those of CS, suggesting that the outer envelope is kinematically related to the inner dense core. Confirming that the ^12^CO lines seldom exhibit deep self-reversal features, whereas this is not unusual for the CS lines, we propose a heuristic model where the outer part is clumpy, but the inner part has a rather smooth density profile, with a uniform temperature and mean density decreasing outward. We apply three-dimensional radiative transfer calculations to this simple model, demonstrating that the essential observational features of the starless cores are successfully reproduced.
402. Counterparts to 1.4GHz sources in ECDF-S
ID:
ivo://CDS.VizieR/J/ApJS/203/15
Title:
Counterparts to 1.4GHz sources in ECDF-S
Short Name:
J/ApJS/203/15
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study a sample of 883 sources detected in a deep Very Large Array survey at 1.4GHz in the Extended Chandra Deep Field South. This paper focuses on the identification of their optical and infrared (IR) counterparts. We use a likelihood-ratio technique that is particularly useful when dealing with deep optical images to minimize the number of spurious associations. We find a reliable counterpart for 95% of our radio sources. Most of the counterparts (74%) are detected at optical wavelengths, but there is a significant fraction (21%) that are only detectable in the IR. Combining newly acquired optical spectra with data from the literature, we are able to assign a redshift to 81% of the identified radio sources (37% spectroscopic). We also investigate the X-ray properties of the radio sources using the Chandra 4Ms and 250ks observations. In particular, we use a stacking technique to derive the average properties of radio objects undetected in the Chandra images. The results of our analysis are collected in a new catalog containing the position of the optical/IR counterpart, the redshift information, and the X-ray fluxes. It is the deepest multi-wavelength catalog of radio sources, which will be used for future study of this galaxy population.
403. Cross-correlation of SDSS QSOs and BOSS galaxies
ID:
ivo://CDS.VizieR/J/ApJ/778/98
Title:
Cross-correlation of SDSS QSOs and BOSS galaxies
Short Name:
J/ApJ/778/98
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the measurement of the two-point cross-correlation function (CCF) of 8198 Sloan Digital Sky Survey Data Release 7 quasars and 349608 Data Release 10 CMASS galaxies from the Baryonic Oscillation Spectroscopic Survey (BOSS) at 0.3<z<0.9. The CCF can be reasonably well fit by a power-law model {xi}_QG_(r)=(r/r_0_)^-{gamma}^ on projected scales of r_p_=2-25h^-1^Mpc with r_0_=6.61+/-0.25h^-1^Mpc and {gamma}=1.69+/-0.07. We estimate a quasar linear bias of b_Q_=1.38+/-0.10 at <z>{=}0.53 from the CCF measurements, which corresponds to a characteristic host halo mass of ~4x10^12^h^-1^M_{sun}_, compared with a ~10^13^h^-1^M_{sun}_ characteristic host halo mass for CMASS galaxies. Based on the clustering measurements, most quasars at {overline}{z}~0.5 are not the descendants of their higher luminosity counterparts at higher redshift, which would have evolved into more massive and more biased systems at low redshift. We divide the quasar sample in luminosity and constrain the luminosity dependence of quasar bias to be db_Q_/dlogL=0.20+/-0.34 or 0.11+/-0.32 (depending on different luminosity divisions) for quasar luminosities -23.5>M_i_(z=2)>-25.5, implying a weak luminosity dependence of clustering for luminous quasars at {overline}{z}~0.5. We compare our measurements with theoretical predictions, halo occupation distribution (HOD) models, and mock catalogs. These comparisons suggest that quasars reside in a broad range of host halos. The host halo mass distributions significantly overlap with each other for quasars at different luminosities, implying a poor correlation between halo mass and instantaneous quasar luminosity. We also find that the quasar HOD parameterization is largely degenerate such that different HODs can reproduce the CCF equally well, but with different satellite fractions and host halo mass distributions. These results highlight the limitations and ambiguities in modeling the distribution of quasars with the standard HOD approach.
404. C stars in SMC
ID:
ivo://CDS.VizieR/J/A+AS/97/603
Title:
C stars in SMC
Short Name:
J/A+AS/97/603
Date:
21 Oct 2021
Publisher:
CDS
Description:
Accurate positions and charts for 1707 carbon stars in the Small Magellanic Cloud identified on GRISM plates are presented. The catalog provides data on magnitudes, colors, and carbon-abundance measurements and can be used for selecting carbon stars with special characteristics.
405. 9C survey at 15GHz
ID:
ivo://CDS.VizieR/J/MNRAS/342/915
Title:
9C survey at 15GHz
Short Name:
J/MNRAS/342/915
Date:
21 Oct 2021
Publisher:
CDS
Description:
The fields chosen for the first observations of the cosmic microwave background with the Very Small Array have been surveyed with the Ryle Telescope at 15GHz. We have covered three regions around RA=00h20m DE=+30{deg}, RA=09h40m DE=+32{deg} and RA=15h40m DE=+43{deg} (J2000.0), an area of 520{deg}^2^. There are 242 sources above the estimated completeness limit of ~25mJy, although a total of ~760 sources have been detected, some as faint as 10mJy.
406. 5C12: survey near the North Galactic Pole
ID:
ivo://CDS.VizieR/J/MNRAS/200/747
Title:
5C12: survey near the North Galactic Pole
Short Name:
J/MNRAS/200/747
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains a deep survey (5C12) of a region close to the North Galactic Pole carried out with the Cambridge One-Mile Telescope at 408 MHz (HPBW 80"x139") and at 1407 MHz (HPBW 23"x40"). The flux densities are on the KPW scale (Kellermann et al. 1969ApJ...157....1K), and were based on 3C48, 3C147 and 3C295. This part of the survey contains 321 sources with apparent flux densities brighter than 9 mJy at 408 MHz or 1.4 mJy at 1407 MHz.
407. 7C: survey of radio sources
ID:
ivo://CDS.VizieR/J/A+AS/110/419
Title:
7C: survey of radio sources
Short Name:
J/A+AS/110/419
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cambridge Low Frequency Synthesis Telescope has been used at 151MHz to survey a region of 418 square degrees centred at RA=17h, DE=65deg, which includes the North Ecliptic Cap. The resolution is 70x70"cosec{delta} and the rms noise on the maps is 25mJy/beam. We present positions and flux densities for 2702 sources which have a signal to noise ratio >5.5 and radio maps of 37 selected extended sources.
408. 10C survey of radio sources at 15.7GHz
ID:
ivo://CDS.VizieR/J/MNRAS/415/2708
Title:
10C survey of radio sources at 15.7GHz
Short Name:
J/MNRAS/415/2708
Date:
21 Oct 2021
Publisher:
CDS
Description:
In a previous paper (Paper I, Franzen et al., 2011MNRAS.415.2699F), the observational, mapping and source-extraction techniques used for the Tenth Cambridge (10C) Survey of Radio Sources were described. Here, the first results from the survey, carried out using the Arcminute Microkelvin Imager Large Array (LA) at an observing frequency of 15.7GHz, are presented. The survey fields cover an area of ~27deg^2^ to a flux-density completeness of 1mJy. Results for some deeper areas, covering ~12deg^2^, wholly contained within the total areas and complete to 0.5mJy, are also presented. The completeness for both areas is estimated to be at least 93 per cent. The 10C survey is the deepest radio survey of any significant extent (>~0.2deg^2^) above 1.4GHz.
409. 7C survey of radio sources at 151 MHz
ID:
ivo://CDS.VizieR/J/MNRAS/246/110
Title:
7C survey of radio sources at 151 MHz
Short Name:
J/MNRAS/246/110
Date:
21 Oct 2021
Publisher:
CDS
Description:
The 7C survey of radio sources is being made with the Cambridge Low-Frequency Synthesis Telescope at 151MHz, with an angular resolution of 70x70cosec{delta}.arcsec^2^. We present the results from one part of of this survey covering 0.144sr in two areas of sky centred at RA=10h28min, DE=41{deg} and RA=06h28min, DE=45{deg} and reaching a limiting flux density of 50mJy. A list of the positions, flux densities and angular sizes of 4723 sources is presented; the position errors are in the range 1-3arcsec for sources with flux densities greater than 500mJy, and the flux density errors are typically 18mJy. About 10 per cent of the sources have apparent angular sizes greater than 60arcsec. The derived source counts are as accurate as those presently available at 405 and 1400MHz and show similar behaviour; in particular the convergence slopes are the same. The median spectral index between 151 and 408MHz remains constant at ~0.9 between 10 and 0.5Jy at 151MHz.
410. 6C Survey of radio sources I.
ID:
ivo://CDS.VizieR/VIII/18
Title:
6C Survey of radio sources I.
Short Name:
VIII/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
The 6th Cambridge Survey of radio sources covers most of the sky north of Dec>30{deg} with an angular resolution of 4.2x4.2cosec{delta} arcmin^2^ and a limiting flux density of 120mJy at 151MHz. This paper, the first of a series, describes the telescope and the methods used to produce the survey maps and source list, and presents maps of a circular area of radius 10{deg} centered on the North Celestial Pole and a list of 1761 sources north of {delta}>+80{deg}.