- ID:
- ivo://CDS.VizieR/J/ApJ/784/9
- Title:
- SCUBA-2 high-redshift galaxies sample
- Short Name:
- J/ApJ/784/9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin^2^ area surrounding the GOODS-N field. The 850 {mu}m rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 {mu}m source catalog to 2 mJy containing 49 sources detected above the 4{sigma} level. We use an ultradeep (11.5 {mu}Jy at 5{sigma}) 1.4 GHz image obtained with the Karl G. Jansky Very Large Array together with observations made with the Submillimeter Array to identify counterparts to the submillimeter galaxies. For most cases of multiple radio counterparts, we can identify the correct counterpart from new and existing Submillimeter Array data. We have spectroscopic redshifts for 62% of the radio sources in the 9' radius highest sensitivity region (556/894) and 67% of the radio sources in the GOODS-N region (367/543). We supplement these with a modest number of additional photometric redshifts in the GOODS-N region (30). We measure millimetric redshifts from the radio to submillimeter flux ratios for the unidentified submillimeter sample, assuming an Arp 220 spectral energy distribution. We find a radio-flux-dependent K-z relation for the radio sources, which we use to estimate redshifts for the remaining radio sources. We determine the star formation rates (SFRs) of the submillimeter sources based on their radio powers and their submillimeter fluxes and find that they agree well. The radio data are deep enough to detect star-forming galaxies with SFRs>2000 M_{sun}_/yr to z~6. We find galaxies with SFRs up to ~6000 M_{sun}_/yr over the redshift range z=1.5-6, but we see evidence for a turn-down in the SFR distribution function above 2000 M_{sun}_/yr.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/832/78
- Title:
- SCUBA-2 & LABOCA obs. of HATLAS ultrared galaxies
- Short Name:
- J/ApJ/832/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Until recently, only a handful of dusty, star-forming galaxies (DSFGs) were known at z>4, most of them significantly amplified by gravitational lensing. Here, we have increased the number of such DSFGs substantially, selecting galaxies from the uniquely wide 250, 350, and 500{mu}m Herschel-ATLAS imaging survey on the basis of their extremely red far-infrared colors and faint 350 and 500{mu}m flux densities, based on which, they are expected to be largely unlensed, luminous, rare, and very distant. The addition of ground-based continuum photometry at longer wavelengths from the James Clerk Maxwell Telescope and the Atacama Pathfinder Experiment allows us to identify the dust peak in their spectral energy distributions (SEDs), with which we can better constrain their redshifts. We select the SED templates that are best able to determine photometric redshifts using a sample of 69 high-redshift, lensed DSFGs, then perform checks to assess the impact of the CMB on our technique, and to quantify the systematic uncertainty associated with our photometric redshifts, {sigma}=0.14(1+z), using a sample of 25 galaxies with spectroscopic redshifts, each consistent with our color selection. For Herschel-selected ultrared galaxies with typical colors of S_500_/S_250_~2.2 and S_500_/S_350_~1.3 and flux densities, S500~50mJy, we determine a median redshift, z_phot_=3.66, an interquartile redshift range, 3.30-4.27, with a median rest-frame 8-1000{mu}m luminosity, L_IR_, of 1.3x10^13^L_{sun}_. A third of the galaxies lie at z>4, suggesting a space density, {rho}_z>4_, of ~6x10^-7^Mpc^-3^. Our sample contains the most luminous known star-forming galaxies, and the most overdense cluster of starbursting proto-ellipticals found to date.
- ID:
- ivo://CDS.VizieR/J/ApJ/653/383
- Title:
- SCUBA observations in Orion A South region
- Short Name:
- J/ApJ/653/383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a 2300arcmin^2^ survey of the Orion A molecular cloud at 450 and 850um using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. The region mapped lies directly south of the OMC 1 cloud core and includes OMC 4, OMC 5, HH 1/2, HH 34, and L1641N. We identify 71 independent clumps in the 850um map and compute size, flux, and degree of central concentration in each.
- ID:
- ivo://CDS.VizieR/J/MNRAS/368/1223
- Title:
- SCUBA observations of cold cores
- Short Name:
- J/MNRAS/368/1223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of a submillimetre continuum emission survey targeted towards 78 star formation regions, 72 of which are devoid of methanol maser and UC HII regions, identified in the Swedish ESO Submillimetre Telescope (SEST)/SEST IMaging Bolometer Array (SIMBA) millimetre continuum survey of Hill et al. (2005, Cat. <J/MNRAS/363/405>). At least 45 per cent of the latter sources, dubbed 'mm-only', detected in this survey are also devoid of the mid-infrared MSX emission. The 450- and 850-um continuum emission was mapped using the Submillimetre Common User Bolometer Array (SCUBA) instrument on the James Clerk Maxwell Telescope (JCMT). Emission is detected towards 97 per cent of the 78 sources targeted as well as towards 28 other SIMBA sources lying in the SCUBA fields. In total, we have identified 212 cores in this submillimetre survey, including 106 previously known from the SIMBA survey. Of the remaining 106 sources, 53 result from resolving a SIMBA source into multiple submillimetre components, whilst the other 53 sources are submillimetre cores, not seen in the SIMBA. Additionally, we have identified two further mm-only sources in the SIMBA images. Of the total 405 sources identified in the SIMBA survey, 255 are only seen at millimetre wavelengths.
- ID:
- ivo://CDS.VizieR/J/MNRAS/436/1919
- Title:
- SCUBA observations of COSMOS galaxies
- Short Name:
- J/MNRAS/436/1919
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present deep 450{mu}m and 850{mu}m observations of a large, uniformly covered 394arcmin^2^ area in the Cosmic Evolution Survey (COSMOS) field obtained with the Scuba-2 instrument on the James Clerk Maxwell Telescope (JCMT). We achieve root-mean-square noise values of {sigma}_450_=4.13mJy and {sigma}_850_=0.80mJy. The differential and cumulative number counts are presented and compared to similar previous works. Individual point sources are identified at >3.6{sigma} significance, a threshold corresponding to a 3-5% sample contamination rate. We identify 78 sources at 450{mu}m and 99 at 850{mu}m, with flux densities S_450_=13-37mJy and S_850_=2-16mJy. Only 62-76% of 450{mu}m sources are 850{mu}m detected and 61-81% of 850{mu}m sources are 450{mu}m detected. The positional uncertainties at 450{mu}m are small (1-2.5 arcsec) and therefore allow a precise identification of multiwavelength counterparts without reliance on detection at 24{mu}m or radio wavelengths; we find that only 44% of 450{mu}m sources and 60% of 850{mu}m sources have 24{mu}m or radio counterparts. 450{mu}m selected galaxies peak at <z>=1.95+/-0.19 and 850{mu}m selected galaxies peak at <z>=2.16+/-0.11. The two samples occupy similar parameter space in redshift and luminosity, while their median SED peak wavelengths differ by ~20-50{mu}m (translating to {Delta}T_dust_=8-12K, where 450{mu}m selected galaxies are warmer). The similarities of the 450{mu}m and 850{mu}m populations, yet lack of direct overlap between them, suggests that submillimetre surveys conducted at any single far-infrared wavelength will be significantly incomplete (>~30%) at censusing infrared-luminous star formation at high z.
- ID:
- ivo://CDS.VizieR/J/ApJ/671/1800
- Title:
- SCUBA observations of {rho} Oph cloud
- Short Name:
- J/ApJ/671/1800
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new multiwavelength submillimeter continuum measurements of the circumstellar dust around 48 young stars in the rho Ophiuchi dark clouds. Supplemented with previous 1.3mm observations of an additional 99 objects from the literature, the statistical distributions of disk masses and submillimeter colors are calculated and compared to those in the Taurus-Auriga region. These basic submillimeter properties of young stellar objects in both environments are shown to be essentially identical.
- ID:
- ivo://CDS.VizieR/J/MNRAS/374/1413
- Title:
- SCUBA survey of Orion
- Short Name:
- J/MNRAS/374/1413
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have re-analysed all of the Submillimetre Common User Bolometer Array (SCUBA) archive data of the Orion star-forming regions. We have put together all of the data taken at different times by different groups. Consequently, we have constructed the deepest submillimetre maps of these regions ever made. There are four regions that have been mapped: Orion A North and South, and Orion B North and South. We find that two of the regions, Orion A North and Orion B North, have deeper sensitivity and completeness limits, and contain a larger number of sources, so we concentrate on these two. We compare the data with archive data from the Spitzer Space Telescope to determine whether or not a core detected in the submillimetre is pre-stellar in nature.
- ID:
- ivo://CDS.VizieR/J/A+A/453/1003
- Title:
- SCUBA ultracompact HII regions
- Short Name:
- J/A+A/453/1003
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a SCUBA submillimetre (450 and 850{mu}m) survey of the environment of 105 IRAS point sources, selected from the Wood and Churchwell (1989ApJS...69..831W) and Kurtz et al. (1994, Cat. J/ApJS/91/659) radio ultracompact (UC) HII region surveys. We detected a total of 155 sub-mm clumps associated with the IRAS point sources and identified three distinct types of object: ultracompact cm-wave sources that are not associated with any sub-mm emission (sub-mm quiet objects), sub-mm clumps that are associated with ultracompact cm-wave sources (radio-loud clumps); and sub-mm clumps that are not associated with any known ultracompact cm-wave sources (radio-quiet clumps). 90% of the sample of IRAS point sources were found to be associated with strong sub-mm emission. We consider the sub-mm colours, morphologies and distance-scaled fluxes of the sample of sub-mm clumps and show that the sub-mm quiet objects are unlikely to represent embedded UC HII regions unless they are located at large heliocentric distances.
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/1099
- Title:
- SCUBA-2 850um obs. of Herschel gal.
- Short Name:
- J/MNRAS/477/1099
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-redshift, luminous, dusty star-forming galaxies (DSFGs) constrain the extremity of galaxy formation theories. The most extreme are discovered through follow-up on candidates in large area surveys. Here, we present extensive 850um SCUBA-2 follow-up observations of 188 red DSFG candidates from the Herschel Multitiered Extragalactic Survey (HerMES) Large Mode Survey, covering 274deg^2^. We detected 87% with a signal-to-noise ratio >3 at 850um. We introduce a new method for incorporating the confusion noise in our spectral energy distribution fitting by sampling correlated flux density fluctuations from a confusion limited map. The new 850um data provide a better constraint on the photometric redshifts of the candidates, with photometric redshift errors decreasing from {sigma}_z_/(1+z)~0.21 to 0.15. Comparison spectroscopic redshifts also found little bias (<(z-z_spec_)/(1+z_spec_)>=0.08). The mean photometric redshift is found to be 3.6 with a dispersion of 0.4 and we identify 21 DSFGs with a high probability of lying at z>4. After simulating our selection effects we find number counts are consistent with phenomenological galaxy evolution models. There is a statistically significant excess of WISE-1 and SDSS sources near our red galaxies, giving a strong indication that lensing may explain some of the apparently extreme objects. Nevertheless, our sample includes examples of galaxies with the highest star formation rates in the Universe (>>10^3^M_{sun}_/yr).
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/1671
- Title:
- SCUBA-2 850um survey in {sigma} Ori cluster
- Short Name:
- J/MNRAS/435/1671
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results from a large 850um survey of the {sigma} Orionis cluster using the SCUBA-2 camera on the James Clerk Maxwell Telescope. The 0.5 diameter circular region we surveyed contains 297 young stellar objects with an age estimated at about 3Myr. We detect nine of these objects, eight of which have infrared excesses from an inner disc. We also serendipitously detect three non-stellar sources at >5{sigma} that are likely background submillimetre galaxies. The nine detected stars have inferred disc masses ranging from 5 to about 17M_Jup_, assuming similar dust properties as Taurus discs and an interstellar medium gas-to-dust ratio of 100. There is a net positive signal towards the positions of the individually undetected infrared excess sources indicating a mean disc mass of 0.5M_Jup_. Stacking the emission towards those stars without infrared excesses constrains their mean disc mass to less than 0.3M_Jup_, or an equivalent Earth mass in dust. The submillimetre luminosity distribution is significantly different from that in the younger Taurus region, indicating disc mass evolution as star-forming regions age and the infrared excess fraction decreases. Submillimetre Array observations reveal CO emission towards four sources demonstrating that some, but probably not much, molecular gas remains in these relatively evolved discs. These observations provide new constraints on the dust and gas mass of protoplanetary discs during the giant planet building phase and provide a reference level for future studies of disc evolution.