- 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.
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Search Results
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/644/990
- Title:
- Sub-mm clumps at 450 and 850{mu}m in M17
- Short Name:
- J/ApJ/644/990
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have mapped a 5.5x5.5pc portion of the M17 massive star-forming region in both 850 and 450{mu}m dust continuum emission using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). The maps reveal more than 100 dusty clumps with deconvolved linear sizes of ~0.05-0.2pc and masses of ~0.8-120M_{sun}_, most of which are not associated with known mid-infrared point sources. Fitting the clump mass function with a double power law gives a mean power-law exponent of {alpha}high=-2.4+/-0.3 for the high-mass power law, consistent with the exponent of the Salpeter stellar mass function. We show that a lognormal clump mass distribution with a peak at 4M_{sun}_ produces as good a fit to the clump mass function as does a double power law. This 4M_{sun}_ peak mass is well above the peak masses of both the stellar initial mass function and the mass function of clumps in low-mass star-forming regions. Despite the difference in intrinsic mass scale, the shape of the M17 clump mass function appears to be consistent with the shape of the core mass function in low-mass star-forming regions. Thus, we suggest that the clump mass function in high-mass star-forming regions may be a scaled up version of that in low-mass regions, instead of its extension to higher masses.
- ID:
- ivo://CDS.VizieR/J/ApJ/639/259
- Title:
- Sub-mm clumps in Orion B South molecular cloud
- Short Name:
- J/ApJ/639/259
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a survey of a 1300arcmin^2^ region of the Orion B South molecular cloud, including NGC 2024, NGC 2023, and the Horsehead Nebula (B33), obtained using the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). Submillimeter continuum observations at 450 and 850{mu}m are discussed. Using an automated algorithm, 57 discrete emission features ("clumps") are identified in the 850{mu}m map.
- ID:
- ivo://CDS.VizieR/J/ApJ/773/168
- Title:
- Submm fluxes of very low-mass stars and BDs
- Short Name:
- J/ApJ/773/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present SCUBA-2 850{mu}m observations of seven very low mass stars (VLMS) and brown dwarfs (BDs). Three are in Taurus and four in the TW Hydrae Association (TWA), and all are classical T Tauri (cTT) analogs. We detect two of the three Taurus disks (one only marginally), but none of the TWA ones. For standard grains in cTT disks, our 3{sigma} limits correspond to a dust mass of 1.2M_{Earth}_ in Taurus and a mere 0.2M_{Earth}_ in the TWA (3-10x deeper than previous work). We combine our data with other submillimeter/millimeter (sub-mm/mm) surveys of Taurus, {rho} Oph, and the TWA to investigate the trends in disk mass and grain growth during the cTT phase.
- ID:
- ivo://CDS.VizieR/J/A+A/466/1065
- Title:
- submm images of IRAS 05358+3543
- Short Name:
- J/A+A/466/1065
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the small-scale structure of massive star-forming regions through interferometric observations in several (sub)mm wavelength bands. These observations resolve multiple sources, yield mass and column density estimates, and give information about the density profiles as well as the dust and temperature properties.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A32
- Title:
- Sub-mm images of SSTB213 J041757.75+274105.5
- Short Name:
- J/A+A/564/A32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed the proto brown dwarf candidate SSTB213 J041757 with the Submillimeter Array to search for CO molecular outflow emission from the source. Our CO maps do not show any outflow emission from the proto brown dwarf candidate. The non-detection implies that the molecular outflows from the source are weak; deeper observations are therefore needed to probe the outflows from the source.
- ID:
- ivo://CDS.VizieR/J/ApJ/559/307
- Title:
- Sub-mm mapping in Orion B molecular cloud
- Short Name:
- J/ApJ/559/307
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a survey of a 900 arcmin^2^ region of the Orion B molecular cloud, including NGC 2068, NGC 2071, and HH 24/25/26, at 850{mu}m using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. Following the techniques developed by Johnstone et al. (2000ApJ...545..327J), we identify 75 independent objects and compute size, flux, and degree of central concentration. Comparison with isothermal, pressure-confined, self-gravitating Bonnor-Ebert spheres implies that the clumps have internal temperatures of 20-40K and surface pressures 5.5<log(P/k)[CGS]<6.5. The clump masses span 0.2-12.3M_{sun}_ assuming typical dust temperatures and a dust emissivity {kappa}_850_=0.01cm^2^/g.
- ID:
- ivo://CDS.VizieR/J/MNRAS/411/505
- Title:
- Sub-mm observations in Extended Chandra DFS
- Short Name:
- J/MNRAS/411/505
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a joint analysis of the overlapping Balloon-borne Large Aperture Submillimetre Telescope (BLAST) 250, 350, 500um, and LABOCA 870um observations [from the LABOCA ECDFS Submm Survey (LESS) survey] of the Extended Chandra Deep Field-South. Out to z~3, the BLAST filters sample near the peak wavelength of thermal far-infrared (FIR) emission from galaxies (rest-frame wavelengths ~60-200um), primarily produced by dust heated through absorption in star-forming clouds. However, identifying counterparts to individual BLAST peaks is very challenging, given the large beams [full-width at half-maximum (FWHM) 36-60 arcsec]. In contrast, the ground-based 870um observations have a significantly smaller 19 arcsec FWHM beam, and are sensitive to higher redshifts (z~1-5, and potentially beyond) due to the more favourable negative K-correction. We use the LESS data, as well as deep Spitzer and VLA imaging, to identify 118 individual sources that produce significant emission in the BLAST bands.
- ID:
- ivo://CDS.VizieR/J/MNRAS/384/1611
- Title:
- Submm observations in gravitational lenses
- Short Name:
- J/MNRAS/384/1611
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a submillimetre mapping survey of faint, gravitationally lensed sources, where we have targeted 12 galaxy clusters and additionally the New Technology Telescope (NTT) Deep Field. The total area surveyed is 71.5arcmin^2^ in the image plane; correcting for gravitational lensing, the total area surveyed is 40arcmin^2^ in the source plane for a typical source redshift z>>2.5. In the deepest maps, an image plane depth of 1{sigma} rms ~0.8mJy is reached. This survey is the largest survey to date to reach such depths. In total 59 sources were detected, including three multiply imaged sources. The gravitational lensing makes it possible to detect sources with flux density below the blank field confusion limit. The lensing-corrected fluxes range from 0.11 to 19mJy. After correcting for multiplicity, there are 10 sources with fluxes <2mJy of which seven have submJy fluxes, doubling the number of such sources known. Number counts are determined below the confusion limit. At 1mJy, the integrated number count is ~10^4^deg^-2^, and at 0.5mJy it is ~2x10^4^deg^-2^. Based on the number counts, at a source plan flux limit of 0.1mJy, essentially all of the 850-m background emission has been resolved. The dominant contribution (>50 per cent) to the integrated background arises from sources with fluxes S850 between 0.4 and 2.5mJy, while the bright sources S850>6mJy contribute only 10 per cent.