- ID:
- ivo://CDS.VizieR/J/other/Nat/458.737
- Title:
- BLAST sources at 250, 350 and 500um
- Short Name:
- J/other/Nat/458.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Submillimetre surveys during the past decade have discovered a population of luminous, high-redshift, dusty starburst galaxies. In the redshift range 1 less than or equal to z less than or equal to 4, these massive submillimetre galaxies go through a phase characterized by optically obscured star formation at rates several hundred times that in the local Universe. Half of the starlight from this highly energetic process is absorbed and thermally re-radiated by clouds of dust at temperatures near 30K with spectral energy distributions peaking at 100um in the rest frame. At 1 less than or equal to z less than or equal to 4, the peak is redshifted to wavelengths between 200 and 500um. The cumulative effect of these galaxies is to yield extragalactic optical and far-infrared backgrounds with approximately equal energy densities. Since the initial detection of the far-infrared background (FIRB), higher-resolution experiments have sought to decompose this integrated radiation into the contributions from individual galaxies. Here we report the results of an extragalactic survey at 250, 350 and 500um. Combining our results at 500 mum with those at 24um, we determine that all of the FIRB comes from individual galaxies, with galaxies at z greater than or equal to 1.2 accounting for 70% of it. As expected, at the longest wavelengths the signal is dominated by ultraluminous galaxies at z>1.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/681/428
- Title:
- BLAST sources in Galactic plane survey
- Short Name:
- J/ApJ/681/428
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from a new 250, 350, and 500um Galactic plane survey taken with the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) in 2005. This survey's primary goal is to identify and characterize high-mass protostellar objects (HMPOs). The region studied here covers 4{deg}^2^ near the open cluster NGC 6823 in the constellation Vulpecula (l=59{deg}). We find 60 compact sources (<60" diameter) detected simultaneously in all three bands. Their SEDs are constrained through BLAST, IRAS, Spitzer MIPS, and MSX photometry, with inferred dust temperatures spanning ~12-40K assuming a dust emissivity index {beta}=1.5. The luminosity-to-mass ratio, a distance-independ ent quantity, spans ~0.2-130L_{sun}_/M_{sun}_. Distances are estimated from coincident ^13^CO(1-0) velocities combined with a variety of other velocity and morphological data in the literature. In total, 49 sources are associated with a molecular cloud complex encompassing NGC 6823 (distance ~2.3kpc), 10 objects with the Perseus arm (~8.5kpc), and one object is probably in the outer Galaxy (~14kpc). Near NGC 6823, the inferred luminosities and masses of BLAST sources span ~40-10^4^L_{sun}_ and ~15-700M_{sun}_, respectively. The mass spectrum is compatible with molecular gas masses in other high-mass star-forming regions. Several luminous sources appear to be ultracompact H II regions powered by early B stars. However, many of the objects are cool, massive gravitationally bound clumps with no obvious internal radiation from a protostar, and hence excellent HMPO candidates.
1743. BLAST survey in Vela-D
- ID:
- ivo://CDS.VizieR/J/ApJ/707/1836
- Title:
- BLAST survey in Vela-D
- Short Name:
- J/ApJ/707/1836
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Balloon-borne Large-Aperture Submillimeter Telescope (BLAST) carried out a 250, 350, and 500um survey of the Galactic plane encompassing the Vela Molecular Ridge, with the primary goal of identifying the coldest dense cores possibly associated with the earliest stages of star formation. Here, we present the results from observations of the Vela-D region, covering about 4deg^2^, in which we find 141 BLAST cores. We exploit existing data taken with the Spitzer MIPS, IRAC, and SEST-SIMBA instruments to constrain their (single-temperature) spectral energy distributions, assuming a dust emissivity index {beta}=2.0. This combination of data allows us to determine the temperature, luminosity, and mass of each BLAST core, and also enables us to separate starless from protostellar sources. We also analyze the effects that the uncertainties on the derived physical parameters of the individual sources have on the overall physical properties of starless and protostellar cores, and we find that there appear to be a smooth transition from the pre- to the protostellar phase. In particular, for protostellar cores we find a correlation between the MIPS24 flux, associated with the central protostar, and the temperature of the dust envelope. We also find that the core mass function of the Vela-D cores has a slope consistent with other similar (sub)millimeter surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/707/1779
- Title:
- BLAST: the redshift survey
- Short Name:
- J/ApJ/707/1779
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Balloon-borne Large Aperture Submillimeter Telescope (BLAST) has recently surveyed ~8.7deg^2^ centered on Great Observatories Origins Deep Survey-South at 250, 350, and 500um. In Dye et al. (2009, Cat. J/ApJ/703/285), we presented the catalog of sources detected at 5{sigma} in at least one band in this field and the probable counterparts to these sources in other wavebands. In this paper, we present the results of a redshift survey in which we succeeded in measuring redshifts for 82 of these counterparts. The spectra show that the BLAST counterparts are mostly star-forming galaxies but not extreme ones when compared to those found in the Sloan Digital Sky Survey. Roughly one quarter of the BLAST counterparts contain an active nucleus. We have also investigated the cases where there are two possible counterparts to the BLAST source, finding that in at least half of these there is evidence that the two galaxies are physically associated, either because they are interacting or because they are in the same large-scale structure. Finally, we have made the first direct measurements of the luminosity function in the three BLAST bands.
1745. BLAST Vela sources
- ID:
- ivo://CDS.VizieR/J/ApJ/707/1824
- Title:
- BLAST Vela sources
- Short Name:
- J/ApJ/707/1824
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present first results from an unbiased 50deg^2^ submillimeter Galactic survey at 250, 350, and 500um from the 2006 flight of the Balloon-borne Large Aperture Submillimeter Telescope. The map has resolution ranging from 36" to 60" in the three submillimeter bands spanning the thermal emission peak of cold starless cores. We determine the temperature, luminosity, and mass of more than 1000 compact sources in a range of evolutionary stages and an unbiased statistical characterization of the population. From comparison with C^18^O data, we find the dust opacity per gas mass, {kappa}r=0.16cm^2^/g at 250um, for cold clumps. We find that 2% of the mass of the molecular gas over this diverse region is in cores colder than 14K, and that the mass function for these cold cores is consistent with a power law with index {alpha}=-3.22+/-0.14 over the mass range 14M_{sun}_<M<80M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/723/915
- Title:
- BLAST view of Aquila star-forming region
- Short Name:
- J/ApJ/723/915
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out the first general submillimeter analysis of the field toward GRSMC 45.46+0.05, a massive star-forming region in Aquila. The deconvolved 6{deg}^2^ (3{deg}x2{deg}) maps provided by BLAST in 2005 at 250, 350, and 500um were used to perform a preliminary characterization of the clump population previously investigated in the infrared, radio, and molecular maps. Interferometric CORNISH data at 4.8GHz have also been used to characterize the Ultracompact HII regions (UCHIIRs) within the main clumps. By means of the BLAST maps, we have produced an initial census of the submillimeter structures that will be observed by Herschel, several of which are known Infrared Dark Clouds.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A86
- Title:
- Blazar candidates among Fermi/LAT 3FGL catalog
- Short Name:
- J/A+A/602/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study to search for, and characterise blazar candidates among the Fermi/LAT 3FGL catalogue using machine-learning classification methods. Classifiers are based on the exploitation of statistical differences imprinted in the 3FGL Fermi/LAT catalogue, such as variability and spectral shape, between different populations of sources.
- ID:
- ivo://CDS.VizieR/J/ApJ/867/131
- Title:
- Blazar candidates behind the Magellanic Clouds
- Short Name:
- J/ApJ/867/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the identification of blazar candidates behind the Magellanic Clouds. The objects were selected from the Magellanic Quasars Survey (MQS), which targeted the entire Large Magellanic Cloud (LMC) and 70% of the Small Magellanic Cloud (SMC). Among the 758 MQS quasars and 898 of the unidentified (featureless spectra) objects, we identified a sample of 44 blazar candidates, including 27 flat-spectrum radio quasars and 17 BL Lacertae objects, respectively. All the blazar candidates from our sample were identified with respect to their radio, optical, and midinfrared properties. The newly selected blazar candidates possess the long-term, multicolor photometric data from the Optical Gravitational Lensing Experiment, multicolor midinfrared observations, and archival radio data for one frequency at least. In addition, for nine of them, the radio polarization data are available. With such data, these objects can be used to study the physics behind the blazar variability detected in the optical and midinfrared bands, as a tool to investigate magnetic field geometry of the LMC and SMC, and as an exemplary sample of point-like sources most likely detectable in the {gamma}-ray range with the newly emerging Cherenkov Telescope Array.
- ID:
- ivo://CDS.VizieR/J/ApJ/609/564
- Title:
- Blazar counterparts for 3EG sources
- Short Name:
- J/ApJ/609/564
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supplementing existing survey data with Very Large Array (VLA) observations, we have extended {gamma}-ray counterpart identifications down to decl.=-40{deg} using our "figure-of-merit" approach. We find blazar counterparts for 70% of EGRET sources above decl.=-40{deg} away from the Galaxy. Spectroscopic confirmation is in progress, and spectra for 24 sources are presented here. We find evidence that increased exposure in the bulge region allowed EGRET to detect relatively faint blazars; a clear excess of nonblazar objects in this region, however, argues for an additional (new) source class.
- ID:
- ivo://CDS.VizieR/J/A+A/556/A71
- Title:
- Blazar 0836+710 long-term multiwavelength studies
- Short Name:
- J/A+A/556/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observation of gamma-ray flares from blazar 0836+710 in 2011, following a period of quiescence, offered an opportunity to study correlated activity at different wavelengths for a high-redshift (z=2.218) active galactic nucleus. Optical and radio monitoring, plus Fermi-LAT gamma-ray monitoring provided 2008-2012 coverage, while Swift offered auxiliary optical, ultraviolet, and X-ray information. Other contemporaneous observations were used to construct a broad-band spectral energy distribution.
