- ID:
- ivo://CDS.VizieR/J/ApJ/858/65
- Title:
- A VLA study of high-redshift GRBs. I. GRB140311A
- Short Name:
- J/ApJ/858/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from a recently concluded study of GRBs at z>~5 with the Karl G. Jansky Very Large Array (VLA). Spanning 1 to 85.5GHz and 7 epochs from 1.5 to 82.3d, our observations of GRB140311A are the most detailed joint radio and millimeter observations of a GRB afterglow at z>~5 to date. In conjunction with optical/near-IR and X-ray data, the observations can be understood in the framework of radiation from a single blast wave shock with energy E_K,iso_~8.5x10^53^erg expanding into a constant density environment with density, n_0_~8cm^-3^. The X-ray and radio observations require a jet break at t_jet_~0.6d, yielding an opening angle of {theta}_jet_~4{deg} and a beaming-corrected blast wave kinetic energy of E_K_~2.2x10^50^erg. The results from our radio follow-up and multiwavelength modeling lend credence to the hypothesis that detected high-redshift GRBs may be more tightly beamed than events at lower redshift. We do not find compelling evidence for reverse shock emission, which may be related to fast cooling driven by the moderately high circumburst density.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/411/102
- Title:
- AzTEC/ASTE 1.1mm observations in the ADF-S
- Short Name:
- J/MNRAS/411/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a 1.1-mm deep survey of the AKARI Deep Field South (ADF-S) with AzTEC mounted on the Atacama Submillimetre Telescope Experiment (ASTE). We obtained a map of 0.25-deg^2^ area with an rms noise level of 0.32-0.71mJy. This is one of the deepest and widest maps thus far at millimetre and submillimetre wavelengths. We uncovered 198 sources with a significance of 3.5{sigma}-15.6{sigma}, providing the largest catalogue of 1.1-mm sources in a contiguous region. Most of the sources are not detected in the far-infrared bands of the AKARI satellite, suggesting that they are mostly at z>=1.5 given the detection limits. We constructed differential and cumulative number counts in the ADF-S, the Subaru/XMM-Newton Deep Field and the SSA 22 field surveyed by AzTEC/ASTE, which provide currently the tightest constraints on the faint end.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/3462
- Title:
- AzTEC/ASTE 1.1mm survey of SSA22
- Short Name:
- J/MNRAS/440/3462
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a 1.1-mm imaging survey of the SSA22 field, known for having an overdensity of z=3.1 Lyman{alpha} emitting galaxies (LAEs), taken with the astronomical thermal emission camera (AzTEC) on the Atacama Submillimeter Telescope Experiment (ASTE). We imaged a 950-arcmin2 field down to a 1{sigma} sensitivity of 0.7-1.3mJy/beam to find 125 submillimetre galaxies (SMGs) with a signal-to-noise ratio >=3.5. Counterpart identification using radio and near/mid-infrared data was performed and one or more counterpart candidates were found for 59 SMGs. Photometric redshifts based on optical to near-infrared images were evaluated for 45 of these SMGs with Spitzer/IRAC data and the median value is found to be z=2.4. By combining these estimations with estimates from the literature, we determined that 10 SMGs might lie within the large-scale structure at z=3.1. The two-point angular cross-correlation function between LAEs and SMGs indicates that the positions of the SMGs are correlated with the z=3.1 protocluster. These results suggest that the SMGs were formed and evolved selectively in the high dense environment of the high-redshift Universe. This picture is consistent with the predictions of the standard model of hierarchical structure formation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/415/3831
- Title:
- AzTEC/ASTE source catalogue
- Short Name:
- J/MNRAS/415/3831
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a 0.72deg^2^ contiguous 1.1-mm survey in the central area of the Cosmological Evolution Survey field carried out to a 1{sigma}~1.26mJy/beam depth with the AzTEC camera mounted on the 10-m Atacama Submillimeter Telescope Experiment. We have uncovered 189 candidate sources at a signal-to-noise ratio (S/N)>=3.5, out of which 129, with S/N>=4, can be considered to have little chance of being spurious (<~2 per cent). We present the number counts derived with this survey, which show a significant excess of sources when compared to the number counts derived from the ~0.5deg^2^ area sampled at similar depths in the Submillimetre Common-User Bolometer Array (SCUBA) HAlf Degree Extragalactic Survey (SHADES).
- ID:
- ivo://CDS.VizieR/J/ApJ/835/55
- Title:
- AzTEC/ASTE survey at 1.1mm toward the SMC
- Short Name:
- J/ApJ/835/55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The first 1.1mm continuum survey toward the Small Magellanic Cloud (SMC) was performed using the AzTEC instrument installed on the ASTE 10m telescope. This survey covered 4.5deg^2^ of the SMC with 1{sigma} noise levels of 5-12mJy/beam, and 44 extended objects were identified. The 1.1mm extended emission has good spatial correlation with Herschel 160{mu}m, indicating that the origin of the 1.1mm extended emission is thermal emission from a cold dust component. We estimated physical properties using the 1.1mm and filtered Herschel data (100, 160, 250, 350, and 500{mu}m). The 1.1mm objects show dust temperatures of 17-45K and gas masses of 4x10^3^-3x10^5^M_{sun}_, assuming single-temperature thermal emission from the cold dust with an emissivity index, {beta}, of 1.2 and a gas-to-dust ratio of 1000. These physical properties are very similar to those of giant molecular clouds (GMCs) in our galaxy and the Large Magellanic Cloud. The 1.1mm objects also displayed good spatial correlation with the Spitzer 24{mu}m and CO emission, suggesting that the 1.1mm objects trace the dense gas regions as sites of massive star formation. The dust temperature of the 1.1mm objects also demonstrated good correlation with the 24{mu}m flux connected to massive star formation. This supports the hypothesis that the heating source of the cold dust is mainly local star-formation activity in the 1.1mm objects. The classification of the 1.1mm objects based on the existence of star-formation activity reveals the differences in the dust temperature, gas mass, and radius, which reflects the evolution sequence of GMCs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/423/529
- Title:
- AzTEC deep-field observations
- Short Name:
- J/MNRAS/423/529
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Instruments using arrays of many bolometers have become increasingly common in the past decade. The maps produced by such instruments typically include the filtering effects of the instrument as well as those from subsequent steps performed in the reduction of the data. Therefore interpretation of the maps is dependent upon accurately calculating the transfer function of the chosen reduction technique on the signal of interest. Many of these instruments use non-linear and iterative techniques to reduce their data because such methods can offer an improved signal-to-noise ratio over those that are purely linear, particularly for signals at scales comparable to that subtended by the array. We discuss a general approach for measuring the transfer function of principal component analysis on point sources that are small compared to the spatial extent seen by any single bolometer within the array. The results are applied to previously released AzTEC catalogues of the Cosmic Evolution Survey (COSMOS), Lockman Hole, Subaru XMM-Newton Deep Field, Great Observatories Origins Deep Survey (GOODS)-North and GOODS-South fields. Source flux density and noise estimates increase by roughly +10 per cent for fields observed while AzTEC was installed at the Atacama Submillimeter Telescope Experiment and +15-25 per cent while AzTEC was installed at the James Clerk Maxwell Telescope. Detection significance is, on average, unaffected by the revised technique. The revised photometry technique will be used in subsequent AzTEC releases.
- ID:
- ivo://CDS.VizieR/J/MNRAS/385/2225
- Title:
- AzTEC millimetre survey of COSMOS field
- Short Name:
- J/MNRAS/385/2225
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a 1.1mm wavelength imaging survey covering 0.3deg^2^ in the COSMOS field. These data, obtained with the AzTEC continuum camera on the James Clerk Maxwell Telescope, were centred on a prominent large-scale structure overdensity which includes a rich X-ray cluster at z>>0.73. A total of 50mm-galaxy candidates, with a significance ranging from 3.5 to 8.5sigma, are extracted from the central 0.15deg^2^ area which has a uniform sensitivity of 1.3mJy/beam. 16 sources are detected with S/N>=4.5, where the expected false-detection rate is zero, of which a surprisingly large number (9) have intrinsic (deboosted) fluxes >=5mJy at 1.1mm.
- ID:
- ivo://CDS.VizieR/J/MNRAS/401/160
- Title:
- AzTEC survey of the SHADES fields. I.
- Short Name:
- J/MNRAS/401/160
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from the largest deep extragalactic mm-wavelength survey undertaken to date. These results are derived from maps covering over 0.7deg^2^, made at {lambda}=1.1mm, using the AzTEC continuum camera mounted on the James Clerk Maxwell Telescope. The maps were made in the two fields originally targeted at {lambda}=850um with the Submillimetre Common-User Bolometer Array (SCUBA) in the SCUBA Half-Degree Extragalactic Survey (SHADES) project, namely the Lockman Hole East (mapped to a depth of 0.9-1.3mJy rms) and the Subaru/XMM-Newton Deep Field (mapped to a depth of 1.0-1.7mJy rms). The wealth of existing and forthcoming deep multifrequency data in these two fields will allow the bright mm source population revealed by these new wide-area 1.1mm images to be explored in detail in subsequent papers. Here, we present the maps themselves, a catalogue of 114 high-significance submillimetre galaxy detections, and a thorough statistical analysis leading to the most robust determination to date of the 1.1mm source number counts. These new maps, covering an area nearly three times greater than the SCUBA SHADES maps, currently provide the largest sample of cosmological volumes of the high-redshift Universe in the mm or sub-mm. Through careful comparison, we find that both the Cosmic Evolution Survey (COSMOS) and the Great Observatories Origins Deep Survey (GOODS) North fields, also imaged with AzTEC, contain an excess of mm sources over the new 1.1mm source-count baseline established here.
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/1845
- Title:
- AzTEC survey of the SHADES fields. II.
- Short Name:
- J/MNRAS/426/1845
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Astronomical Thermal Emission Camera (AzTEC) 1.1mm survey of the two SCUBA HAlf Degree Extragalactic Survey (SHADES) fields is the largest (0.7deg^2^) blank-field millimetre-wavelength (mm-wavelength) survey undertaken to date at a resolution of 18arcsec and a depth of 1mJy. We have used the deep optical to radio multiwavelength data in the SHADES Lockman Hole East and SXDF/UDS fields to obtain galaxy identifications for 64 per cent (80 per cent including tentative identifications) of the 148 AzTEC-SHADES 1.1mm sources reported by Austermann et al., exploiting deep radio and 24um data complemented by methods based on 8um flux density and red optical-infrared (i-K) colour.
- ID:
- ivo://CDS.VizieR/J/A+A/606/A35
- Title:
- Barnard 1b-N and 1b-S 350GHz images
- Short Name:
- J/A+A/606/A35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation epoch of protostellar disks is debated because of the competing roles of rotation, turbulence, and magnetic fields in the early stages of low-mass star formation. Magnetohydrodynamics simulations of collapsing cores predict that rotationally supported disks may form in strongly magnetized cores through ambipolar diffusion or misalignment between the rotation axis and the magnetic field orientation. Detailed studies of individual sources are needed to cross check the theoretical predictions. We present 0.06-0.1arcsec resolution images at 350GHz toward B1b-N and B1b-S, which are young class 0 protostars, possibly first hydrostatic cores. The images have been obtained with ALMA, and we compare these data with magnetohydrodynamics simulations of a collapsing turbulent and magnetized core. The submillimeter continuum emission is spatially resolved by ALMA. Compact structures with optically thick 350GHz emission are detected toward both B1b-N and B1b-S, with 0.2 and 0.35arcsec radii (46 and 80au at the Perseus distance of 230pc), within a more extended envelope. The flux ratio between the compact structure and the envelope is lower in B1b-N than in B1b-S, in agreement with its earlier evolutionary status. The size and orientation of the compact structure are consistent with 0.2arcsec resolution 32GHz observations obtained with the Very Large Array as a part of the VANDAM survey, suggesting that grains have grown through coagulation. The morphology, temperature, and densities of the compact structures are consistent with those of disks formed in numerical simulations of collapsing cores. Moreover, the properties of B1b-N are consistent with those of a very young protostar, possibly a first hydrostatic core. These observations provide support for the early formation of disks around low-mass protostars.