- ID:
- ivo://CDS.VizieR/J/ApJ/757/83
- Title:
- The Blanco Cosmology Survey (BCS)
- Short Name:
- J/ApJ/757/83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Blanco Cosmology Survey (BCS) is a 60 night imaging survey of ~80deg^2^ of the southern sky located in two fields: (5hr,-55{deg}) and (23hr,-55{deg}). The survey was carried out between 2005 and 2008 in griz bands with the Mosaic2 imager on the Blanco 4m telescope. The primary aim of the BCS survey is to provide the data required to optically confirm and measure photometric redshifts for Sunyaev-Zel'dovich effect selected galaxy clusters from the South Pole Telescope and the Atacama Cosmology Telescope. We process and calibrate the BCS data, carrying out point-spread function-corrected model-fitting photometry for all detected objects. The median 10{sigma} galaxy (point-source) depths over the survey in griz are approximately 23.3 (23.9), 23.4 (24.0), 23.0 (23.6), and 21.3 (22.1), respectively. The astrometric accuracy relative to the USNO-B survey is ~45mas. We calibrate our absolute photometry using the stellar locus in grizJ bands, and thus our absolute photometric scale derives from the Two Micron All Sky Survey, which has ~2% accuracy. The scatter of stars about the stellar locus indicates a systematic floor in the relative stellar photometric scatter in griz that is ~1.9%, ~2.2%, ~2.7%, and ~2.7%, respectively. A simple cut in the AstrOmatic star-galaxy classifier spread_ model produces a star sample with good spatial uniformity. We use the resulting photometric catalogs to calibrate photometric redshifts for the survey and demonstrate scatter {delta}z/(1+z)=0.054 with an outlier fraction {eta}<5% to z~1. We highlight some selected science results to date and provide a full description of the released data products.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/157/148
- Title:
- The blueshift of the C IV broad emission line in QSOs
- Short Name:
- J/AJ/157/148
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For the sample from Ge et al. (2016MNRAS.462..966G) of 87 low-z Palomar-Green quasi-stellar objects (QSOs) and 130 high-z QSOs (0<z<5) with H{beta}-based single-epoch supermassive black hole masses, we perform a uniform decomposition of the C IV {lambda}1549 broad-line profile. Based on the rest frame defined by the [O III] {lambda}5007 narrow emission line, a medium-strong positive correlation is found between the C IV blueshift and the luminosity at 5100 {AA} or the Eddington ratio L_Bol_/L_Edd_. A medium-strong negative relationship is found between the C IV blueshift and C IV equivalent width. These results support the postulation where the radiation pressure may be the driver of C IV blueshift. There is a medium-strong correlation between the mass ratio of C IV-based to H{beta}-based M_BH_ and the C IV blueshift, which indicates that the bias for C IV-based M_BH_ is affected by the C IV profile.
18693. The Bok globule CB 26
- ID:
- ivo://CDS.VizieR/J/A+A/646/A18
- Title:
- The Bok globule CB 26
- Short Name:
- J/A+A/646/A18
- Date:
- 23 Mar 2022 16:32:20
- Publisher:
- CDS
- Description:
- Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins. We study the physical structure and grain growth in the edge-on disk that surrounds the ~1Myr old low-mass (~0.55M_{sun}_) protostar embedded in the Bok Globule CB26 to examine how much grain growth has already occurred in the protostellar phase. We combine the SED between 0.9um and 6.4cm with high angular resolution continuum maps at 1.3, 2.9, and 8.1mm, and use the radiative transfer code RADMC-3D to conduct a detailed modelling of the dust emission from the disk and envelope of CB 26. We infer inner and outer disk radii of around 16au and 172+/-22au, respectively. The total gas mass in the disk is ~0.076M_{sun}_, which amounts to ~14% of the mass of the central star. The inner disk contains a compact free-free emission region, which could be related to either a jet or a photoevaporation region. The thermal dust emission from the outer disk is optically thin at mm wavelengths, while the emission from the inner disk midplane is moderately optically thick. Our best-fit radiative transfer models indicate that the dust grains in the disk have already grown to pebbles with diameters of the order of 10cm in size. Residual 8.1mm emission suggests the presence of even larger particles in the inner disk. For the optically thin mm dust emission from the outer disk, we derive a mean opacity slope of {beta}_mm_~=0.7+/-0.4, which is consistent with the presence of large dust grains. The presence of cm-sized bodies in the CB 26 disk indicates that solids grow rapidly already during the first million years in a protostellar disk. It is thus possible that Class II disks are already seeded with large particles and may contain even planetesimals.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/195/14
- Title:
- The Bolocam Galactic Plane Survey (BGPS). V.
- Short Name:
- J/ApJS/195/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of observations of 1882 sources in the Bolocam Galactic Plane Survey (BGPS) at 1.1mm with the 10m Henrich Hertz Telescope simultaneously in HCO^+^J=3-2 and N_2_H^+^J=3-2. We detect 77% of these sources in HCO^+^ and 51% in N_2_H^+^ at greater than 3{sigma}. We find a strong correlation between the integrated intensity of both dense gas tracers and the 1.1mm dust emission of BGPS sources. We determine kinematic distances for 529 sources (440 in the first quadrant breaking the distance ambiguity and 89 in the second quadrant). We derive the size, mass, and average density for this subset of clumps. The median size of BGPS clumps is 0.75pc with a median mass of 330M_{sun}_ (assuming T_Dust_=20K). BGPS clumps represent a wide range of objects (from dense cores to more diffuse clumps) and are typically characterized by larger sizes and lower densities than previously published surveys of high-mass star-forming regions.
- ID:
- ivo://CDS.VizieR/J/ApJS/188/123
- Title:
- The Bolocam Galactic Plane Survey. II.
- Short Name:
- J/ApJS/188/123
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 8358 sources extracted from images produced by the Bolocam Galactic Plane Survey (BGPS). The BGPS is a survey of the millimeter dust continuum emission from the northern Galactic plane. The catalog sources are extracted using a custom algorithm, Bolocat, which was designed specifically to identify and characterize objects in the large-area maps generated from the Bolocam instrument. The catalog products are designed to facilitate follow-up observations of these relatively unstudied objects. The catalog is 98% complete from 0.4Jy to 60Jy over all object sizes for which the survey is sensitive (<3.5'). We find that the sources extracted can best be described as molecular clumps-large dense regions in molecular clouds linked to cluster formation. We find that the flux density distribution of sources follows a power law with dN/dS{prop.to}S^-2.4+/-0.1^ and that the mean Galactic latitude for sources is significantly below the midplane: <b>=(-0.095+/-0.001{deg}).
- ID:
- ivo://CDS.VizieR/J/ApJ/824/86
- Title:
- The BOSS emission-line lens survey. III.
- Short Name:
- J/ApJ/824/86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce the Baryon Oscillation Spectroscopic Survey (BOSS) Emission-Line Lens Survey GALaxy-Ly{alpha} EmitteR sYstems (BELLS GALLERY) Survey, which is a Hubble Space Telescope program to image a sample of galaxy-scale strong gravitational lens candidate systems with high-redshift Ly{alpha} emitters (LAEs) as the background sources. The goal of the BELLS GALLERY Survey is to illuminate dark substructures in galaxy-scale halos by exploiting the small-scale clumpiness of rest-frame far-UV emission in lensed LAEs, and to thereby constrain the slope and normalization of the substructure-mass function. In this paper, we describe in detail the spectroscopic strong-lens selection technique, which is based on methods adopted in the previous Sloan Lens ACS (SLACS) Survey, BELLS, and SLACS for the Masses Survey. We present the BELLS GALLERY sample of the 21 highest-quality galaxy-LAE candidates selected from ~1.4x10^6^ galaxy spectra in the BOSS of the Sloan Digital Sky Survey III. These systems consist of massive galaxies at redshifts of approximately 0.5 strongly lensing LAEs at redshifts from 2-3. The compact nature of LAEs makes them an ideal probe of dark substructures, with a substructure-mass sensitivity that is unprecedented in other optical strong-lens samples. The magnification effect from lensing will also reveal the structure of LAEs below 100 pc scales, providing a detailed look at the sites of the most concentrated unobscured star formation in the universe. The source code used for candidate selection is available for download as a part of this release.
- ID:
- ivo://CDS.VizieR/J/AJ/151/82
- Title:
- The 4 brightest red giants in the UFD galaxy Ret 2
- Short Name:
- J/AJ/151/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ultra-faint dwarf (UFD) galaxy Reticulum 2 (Ret 2) was recently discovered in images obtained by the Dark Energy Survey (Diehl et al. 2014SPIE.9149E..0VD). We have observed the four brightest red giants in Ret 2 at high spectral resolution using the Michigan/Magellan Fiber System. We present detailed abundances for as many as 20 elements per star, including 12 elements heavier than the Fe group. We confirm previous detection of high levels of r-process material in Ret 2 (mean [Eu/Fe]=+1.69+/-0.05) found in three of these stars (mean [Fe/H]=-2.88+/-0.10). The abundances closely match the r-process pattern found in the well-studied metal-poor halo star CS 22892-052. Such r-process-enhanced stars have not been found in any other UFD galaxy, though their existence has been predicted by at least one model. The fourth star in Ret 2 ([Fe/H]=-3.42+/-0.20) contains only trace amounts of Sr ([Sr/Fe]=-1.73+/-0.43) and no detectable heavier elements. One r-process enhanced star is also enhanced in C (natal [C/Fe]~+1.1). This is only the third such star known, which suggests that the nucleosynthesis sites leading to C and r-process enhancements are decoupled. The r-process-deficient star is enhanced in Mg ([Mg/Fe]=+0.81+/-0.14), and the other three stars show normal levels of {alpha}-enhancement (mean [Mg/Fe]=+0.34+/-0.03). The abundances of other {alpha} and Fe-group elements closely resemble those in UFD galaxies and metal-poor halo stars, suggesting that the nucleosynthesis that led to the large r-process enhancements either produced no light elements or produced light-element abundance signatures indistinguishable from normal supernovae.
- ID:
- ivo://CDS.VizieR/J/AJ/149/158
- Title:
- The BUD sample. I. L dwarf activity sample
- Short Name:
- J/AJ/149/158
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the colors and activity of ultracool (M7-L8) dwarfs from the Tenth Data Release of the Sloan Digital Sky Survey (SDSS). We combine previous samples of SDSS M and L dwarfs with new data obtained from the Baryon Oscillation Sky Survey (BOSS) to produce the BOSS Ultracool Dwarf (BUD) sample of 11820 M7-L8 dwarfs. By combining SDSS data with photometry from 2MASS and the Wide-field Infrared Sky Explorer (WISE) mission, we present ultracool dwarf colors from i-z to W2-W3 as a function of spectral type, and extend the SDSS-2MASS-WISE color locus to include ultracool dwarfs. The i-z, i-J, and z-J colors provide the best indication of spectral type for M7-L3 dwarfs. We also examine ultracool dwarf chromospheric activity through the presence and strength of H{alpha} emission. The fraction of active dwarfs rises through the M spectral sequence until it reaches ~90% at spectral type L0. The fraction of active dwarfs then declines to 50% at spectral type L5; no H{alpha} emission is observed in the late-L dwarfs in the BUD sample. The fraction of active L0-L5 dwarfs is much higher than previously observed. The strength of activity declines with spectral type from M7 through L3, after which the data do not show a clear trend. Using one-dimensional chromosphere models, we explore the range of filling factors and chromospheric temperature structures that are consistent with H{alpha} observations of M0-L7 dwarfs. M dwarf chromospheres have a similar, smoothly varying range of temperature and surface coverage, while L dwarf chromospheres are cooler and have smaller filling factors.
18700. The B3-VLA Quasar Sample
- ID:
- ivo://CDS.VizieR/J/A+AS/123/219
- Title:
- The B3-VLA Quasar Sample
- Short Name:
- J/A+AS/123/219
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new low frequency radio selected Sample of 125 Quasars complete down to 100mJy at 408MHz is presented in this paper. The sample is a part of the B3-VLA sample: 1050 radiosources selected from the B3 catalogue at 408MHz and observed at the VLA (1465MHz, C and A configurations). Out of the 352 sources, identified on the POSS-I down to m_r_~20.0, 172 are quasar candidates. In this paper we give the final assessment of the quasar sample from spectroscopic observations of the candidates. The final complete quasar sample consists of 125 objects. Furthermore 3 Bl Lac objects have been identified and two Bl Lac candidates.