- ID:
- ivo://CDS.VizieR/J/ApJ/721/137
- Title:
- The Bolocam Galactic Plane Survey (BGPS)
- Short Name:
- J/ApJ/721/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Bolocam Galactic Plane Survey (BGPS) data for a 6deg^2^ region of the Galactic plane containing the Galactic center are analyzed and compared to infrared and radio continuum data. The BGPS 1.1mm emission consists of clumps interconnected by a network of fainter filaments surrounding cavities, a few of which are filled with diffuse near-IR emission indicating the presence of warm dust or with radio continuum characteristic of HII regions or supernova remnants. New 350um images of the environments of the two brightest regions, Sgr A and B, are presented. Sgr B2 is the brightest millimeter-emitting clump in the Central Molecular Zone (CMZ) and may be forming the closest analog to a super star cluster in the Galaxy. The CMZ contains the highest concentration of millimeter- and submillimeter-emitting dense clumps in the Galaxy. Most 1.1mm features at positive longitudes are seen in silhouette against the 3.6-24um background observed by the Spitzer Space Telescope. However, only a few clumps at negative longitudes are seen in absorption, confirming the hypothesis that positive longitude clumps in the CMZ tend to be on the near side of the Galactic center, consistent with the suspected orientation of the central bar in our Galaxy. The Bolocat catalog of 1.1mm clumps contains 1428 entries in the Galactic center between l=358.5{deg} and l=4.5{deg} of which about 80% are likely to be within about 500pc of the center.
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- ID:
- ivo://CDS.VizieR/J/ApJS/224/5
- Title:
- The Herschel Orion Protostar Survey (HOPS): SEDs
- Short Name:
- J/ApJS/224/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present key results from the Herschel Orion Protostar Survey (HOPS): spectral energy distributions (SEDs) and model fits of 330 young stellar objects, predominantly protostars, in the Orion molecular clouds. This is the largest sample of protostars studied in a single, nearby star formation complex. With near-infrared photometry from 2MASS, mid- and far-infrared data from Spitzer and Herschel, and submillimeter photometry from APEX, our SEDs cover 1.2-870{mu}m and sample the peak of the protostellar envelope emission at ~100{mu}m. Using mid-IR spectral indices and bolometric temperatures, we classify our sample into 92 Class 0 protostars, 125 Class I protostars, 102 flat-spectrum sources, and 11 Class II pre-main-sequence stars. We implement a simple protostellar model (including a disk in an infalling envelope with outflow cavities) to generate a grid of 30400 model SEDs and use it to determine the best-fit model parameters for each protostar. We argue that far-IR data are essential for accurate constraints on protostellar envelope properties. We find that most protostars, and in particular the flat-spectrum sources, are well fit. The median envelope density and median inclination angle decrease from Class 0 to Class I to flat-spectrum protostars, despite the broad range in best-fit parameters in each of the three categories. We also discuss degeneracies in our model parameters. Our results confirm that the different protostellar classes generally correspond to an evolutionary sequence with a decreasing envelope infall rate, but the inclination angle also plays a role in the appearance, and thus interpretation, of the SEDs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/196
- Title:
- The invisible AGN catalogue
- Short Name:
- J/MNRAS/468/196
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A large fraction of active galactic nuclei (AGN) are 'invisible' in extant optical surveys due to either distance or dust-obscuration. The existence of this large population of dust-obscured, infrared (IR)-bright AGN is predicted by models of galaxy-supermassive black hole coevolution and is required to explain the observed X-ray and IR backgrounds. Recently, IR colour cuts with Wide-field Infrared Survey Explorer have identified a portion of this missing population. However, as the host galaxy brightness relative to that of the AGN increases, it becomes increasingly difficult to differentiate between IR emission originating from the AGN and from its host galaxy. As a solution, we have developed a new method to select obscured AGN using their 20-cm continuum emission to identify the objects as AGN. We created the resulting invisible AGN catalogue by selecting objects that are detected in AllWISE (mid-IR) and FIRST (20 cm), but are not detected in SDSS (optical) or 2MASS (near-IR), producing a final catalogue of 46 258 objects. 30 per cent of the objects are selected by existing selection methods, while the remaining 70 per cent represent a potential previously unidentified population of candidate AGN that are missed by mid-IR colour cuts. Additionally, by relying on a radio continuum detection, this technique is efficient at detecting radio-loud AGN at z>=0.29, regardless of their level of dust obscuration or their host galaxy's relative brightness.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/55
- Title:
- The SPT-SZ catalog at 95, 150, and 220GHz
- Short Name:
- J/ApJ/900/55
- Date:
- 21 Mar 2022 09:29:14
- Publisher:
- CDS
- Description:
- We present a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530 square degree area surveyed with the South Pole Telescope (SPT) from 2008-2011 in three bands centered at 95, 150, and 220GHz. The catalog contains 4845 sources measured at a significance of 4.5{sigma} or greater in at least one band, corresponding to detections above approximately 9.8, 5.8, and 20.4mJy in 95, 150, and 220GHz, respectively. The spectral behavior in the SPT bands is used for source classification into two populations based on the underlying physical mechanisms of compact, emissive sources that are bright at millimeter wavelengths: synchrotron radiation from active galactic nuclei and thermal emission from dust. The latter population includes a component of high-redshift sources often referred to as submillimeter galaxies (SMGs). In the relatively bright flux ranges probed by the survey, these sources are expected to be magnified by strong gravitational lensing. The survey also contains sources consistent with protoclusters, groups of dusty galaxies at high redshift undergoing collapse. We cross-match the SPT-SZ catalog with external catalogs at radio, infrared, and X-ray wavelengths and identify available redshift information. The catalog splits into 3980 synchrotron-dominated and 865 dust-dominated sources, and we determine a list of 506 SMGs. Ten sources in the catalog are identified as stars. We calculate number counts for the full catalog, and synchrotron and dusty components, using a bootstrap method and compare our measured counts with models. This paper represents the third and final catalog of point sources in the SPT-SZ survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/712/925
- Title:
- Transition circumstellar disks in Ophiuchus
- Short Name:
- J/ApJ/712/925
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained millimeter-wavelength photometry, high-resolution optical spectroscopy, and adaptive optics near-infrared imaging for a sample of 26 Spitzer-selected transition circumstellar disks. All of our targets are located in the Ophiuchus molecular cloud (d~125pc) and have spectral energy distributions (SEDs) suggesting the presence of inner opacity holes. We use these ground-based data to estimate the disk mass, multiplicity, and accretion rate for each object in our sample in order to investigate the mechanisms potentially responsible for their inner holes. We find that transition disks are a heterogeneous group of objects, with disk masses ranging from <0.6 to 40M_JUP_ and accretion rates ranging from <10^-11^ to 10^-7^M_{sun}_/yr, but most tend to have much lower masses and accretion rates than "full disks" (i.e., disks without opacity holes). Eight of our targets have stellar companions: six of them are binaries and the other two are triple systems. In four cases, the stellar companions are close enough to suspect they are responsible for the inferred inner holes. We find that nine of our 26 targets have low disk mass (<2.5M_JUP_) and negligible accretion (<10^-11^M_{sun}_/yr), and are thus consistent with photoevaporating (or photoevaporated) disks. Four of these nine non-accreting objects have fractional disk luminosities <10^-3^ and could already be in a debris disk stage. Seventeen of our transition disks are accreting. Thirteen of these accreting objects are consistent with grain growth. The remaining four accreting objects have SEDs suggesting the presence of sharp inner holes, and thus are excellent candidates for harboring giant planets.
- ID:
- ivo://CDS.VizieR/J/ApJ/749/79
- Title:
- Transition disks. II. Southern MoC
- Short Name:
- J/ApJ/749/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Transition disk objects are pre-main-sequence stars with little or no near-IR excess and significant far-IR excess, implying inner opacity holes in their disks. Here we present a multifrequency study of transition disk candidates located in Lupus I, III, IV, V, VI, Corona Australis, and Scorpius. Complementing the information provided by Spitzer with adaptive optics (AO) imaging (NaCo, VLT), submillimeter photometry (APEX), and echelle spectroscopy (Magellan, Du Pont Telescopes), we estimate the multiplicity, disk mass, and accretion rate for each object in our sample in order to identify the mechanism potentially responsible for its inner hole. We find that our transition disks show a rich diversity in their spectral energy distribution morphology, have disk masses ranging from <~1 to 10M_JUP_, and accretion rates ranging from <~10^-11^ to 10^-7.7^M_{sun}_/yr. Of the 17 bona fide transition disks in our sample, three, nine, three, and two objects are consistent with giant planet formation, grain growth, photoevaporation, and debris disks, respectively. Two disks could be circumbinary, which offers tidal truncation as an alternative origin of the inner hole.
- ID:
- ivo://CDS.VizieR/J/A+A/592/A126
- Title:
- Transition disk survey
- Short Name:
- J/A+A/592/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding disk evolution and dissipation is essential for studies of planet formation. Transition disks, i.e., disks with large dust cavities and gaps, are promising candidates of active evolution. About two dozen candidates, selected by their Spectral Energy Distribution (SED), have been confirmed to have dust cavities through millimeter interferometric imaging, but this sample is biased toward the brightest disks. The Spitzer surveys of nearby low-mass star-forming regions have resulted in more than 4000 young stellar objects (YSOs). Using color criteria, we selected a sample of ~150 candidates and an additional 40 candidates and known transition disks from the literature. The Spitzer data were complemented by new observations at longer wavelengths, including new JCMT and APEX submillimeter photometry, and WISE and Herschel-PACS mid- and far-infrared photometry. Furthermore, optical spectroscopy was obtained and stellar types were derived for 85% of the sample, including information from the literature. The SEDs were fit to a grid of RADMC-3D disk models with a limited number of parameters: disk mass, inner disk mass, scale height and flaring, and disk cavity radius, where the latter is the main parameter of interest. About 72% of our targets possibly have dust cavities based on the SED. The derived cavity sizes are consistent with imaging/modeling results in the literature, where available. Trends are found with the L_disk_ over L_*_ ratio and stellar mass and a possible connection with exoplanet orbital radii. A comparison with a previous study where color observables are used (Cieza et al., 2010, Cat. J/ApJ/712/925) reveals large overlap between their category of planet-forming disks and our transition disks with cavities. A large number of the new transition disk candidates are suitable for follow-up observations with ALMA.
- ID:
- ivo://CDS.VizieR/J/MNRAS/396/964
- Title:
- T Tauri in and around bright-rimmed clouds
- Short Name:
- J/MNRAS/396/964
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to quantitatively testify the 'small-scale sequential star formation' hypothesis in and around bright-rimmed clouds (BRCs). As a continuation of the recent attempt by Ogura et al. (2007PASJ...59..199O), we have carried out BVIc photometry of four more BRC aggregates along with deeper re-observations of two previously observed BRCs. Again, quantitative age gradients are found in almost all the BRCs studied in the present work. Archival Spitzer/Infrared Array Camera data also support this result.
- ID:
- ivo://CDS.VizieR/J/A+A/525/A47
- Title:
- U-band photometry in sigma Orionis region
- Short Name:
- J/A+A/525/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the results of an U band survey with FORS1/VLT of a large area in the sigma Ori star-forming region. We combine the U-band photometry with literature data to compute accretion luminosity and mass accretion rates from the U-band excess emission for all objects (187) detected by Spitzer in the FORS1 field and classified by Hernandez et al. (2007, Cat. J/ApJ/662/1067) as likely members of the cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/561/A49
- Title:
- 867um image of SBS 0335-052 with ALMA
- Short Name:
- J/A+A/561/A49
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0 Band 7 observations of an extremely metal-poor dwarf starburst galaxy in the Local Universe, SBS 0335-052 (12+log(O/H)~7.2). With these observations, dust is detected at 870um (ALMA Band 7), but 87% of the flux in this band is due to free-free emission from the starburst.
