- ID:
- ivo://CDS.VizieR/J/ApJ/749/10
- Title:
- SDSS observations of Kuiper belt objects
- Short Name:
- J/ApJ/749/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Colors of trans-Neptunian objects (TNOs) are used to study the evolutionary processes of bodies in the outskirts of the solar system and to test theories regarding their origin. Here I describe a search for serendipitous Sloan Digital Sky Survey (SDSS) observations of known TNOs and Centaurs. I present a catalog of SDSS photometry, colors, and astrometry of 388 measurements of 42 outer solar system objects. I find weak evidence, at the {approx} 2{sigma} level (per trial), for a correlation between the g - r color and inclination of scattered disk objects and hot classical Kuiper Belt objects. I find a correlation between the g - r color and the angular momentum in the z direction of all the objects in this sample. These findings should be verified using larger samples of TNOs. Light curves as a function of phase angle are constructed for 13 objects. The steepness of the slopes of these light curves suggests that the coherent backscatter mechanism plays a major role in the reflectivity of outer solar system small objects at small phase angles. I find weak evidence for an anticorrelation, significant at the 2{sigma} confidence level (per trial), between the g-band phase-angle slope parameter and the semimajor axis, as well as the aphelion distance, of these objects (i.e., they show a more prominent "opposition effect" at smaller distances from the Sun). However, this plausible correlation should be verified using a larger sample. I discuss the origin of this possible correlation and argue that if this correlation is real it probably indicates that "Sedna"-like objects have a different origin than other classes of TNOs. Finally, I identify several objects with large variability amplitudes.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/124/2164
- Title:
- SDSS photometry in the field of L1457
- Short Name:
- J/AJ/124/2164
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic and photometric survey of a sample of field stars in the region of the molecular cloud L1457. High-quality coude feed spectra, together with five-band photometry in the Sloan Digital Sky Survey system and near-infrared archival data from the Two Micron All Sky Survey, are used to derive color excesses and distances for the stars. Based on these data, a new distance estimate of 360+/-30pc is derived for the cloud, supporting recent results by K.L. Luhman, 2001ApJ...560..287L. The data further indicate that the north-south velocity gradient seen in the millimeter-wave CO data is mirrored in a distance gradient, with the northern part of the cloud being closer to us. A second, less opaque, layer of extinction is detected at ~80pc. This distance is consistent with the earlier distance estimates to the cloud, based on Na I absorption. We identify this layer with the wall of the hot Local Bubble. Hence, the dense cloud is not, as previously thought, associated with the Local Bubble.
- ID:
- ivo://CDS.VizieR/J/MNRAS/394/340
- Title:
- SDSS photometry of HI-selected galaxies
- Short Name:
- J/MNRAS/394/340
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Parkes Multibeam system and the Sloan Digital Sky Survey to assemble a sample of 195 galaxies selected originally from their HI signature to avoid biases against unevolved or low surface brightness objects. For each source nine intrinsic properties are measured homogeneously, as well as inclination and an optical spectrum. The sample, which should be almost entirely free of either misidentification or confusion, includes a wide diversity of galaxies ranging from inchoate, low surface brightness dwarfs to giant spirals. Despite this diversity there are five clear correlations among their properties. They include a common dynamical mass-to-light ratio within their optical radii, a correlation between surface brightness and luminosity and a common HI surface density. Such correlation should provide strong constrains on models of galaxy formation and evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/139/1212
- Title:
- SDSS photometry of interacting galaxies
- Short Name:
- J/AJ/139/1212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used the Galaxy Evolution Explorer (GALEX) ultraviolet telescope to study stellar populations and star formation morphology in a well-defined sample of 42 nearby optically selected pre-merger interacting galaxy pairs. Galaxy interactions were likely far more common in the early universe than in the present; thus our study provides a nearby well-resolved comparison sample for high-redshift studies. We have combined the GALEX near-ultraviolet (NUV) and far-ultraviolet images with broadband optical maps from the Sloan Digitized Sky Survey to investigate the ages and extinctions of the tidal features and the disks.
- ID:
- ivo://CDS.VizieR/J/MNRAS/430/2358
- Title:
- SDSS photometry of LMC cluster SL 529
- Short Name:
- J/MNRAS/430/2358
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results on the age and metallicity estimates of the poorly studied Large Magellanic Cloud (LMC) cluster SL 529, from CCD SDSS gr photometry obtained at the Gemini South telescope with the GMOS attached. The cluster main-sequence turnoffs (MSTO) region possesses an extended structure, with an age spread (~0.5Gyr) bigger than the mean age width of known extended MSTO (EMSTO) LMC clusters. We report for the first time a mean cluster age of 2.25Gyr and a mean cluster metallicity of Z=0.004, which place it as the most metal-poor and oldest cluster in the EMSTO LMC cluster group. In addition, the cluster red clump appears to be formed by two concentrations of stars - although it is not clear whether this feature can be caused, in part, by binary interactions and mergers - whereas the cluster core radius of 4.2pc is in excellent agreement with those determined for the previously 12 known EMSTO LMC clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/387/1323
- Title:
- SDSS photometry of luminous red galaxies
- Short Name:
- J/MNRAS/387/1323
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the AAT-AAOmega LRG Pilot observing run to establish the feasibility of a large spectroscopic survey using the new AAOmega instrument. We have selected luminous red galaxies (LRGs) using single epoch SDSS riz-photometry to i<20.5 and z<20.2. We have observed in three fields including the COSMOS field and the COMBO-17 S11 field, obtaining a sample of ~600 redshift z>~0.5 LRGs. Exposure times varied from 14h to determine the minimum exposure for AAOmega to make an essentially complete LRG redshift survey in average conditions. We show that LRG redshifts to i<20.5 can be measured in >>1.5h exposures and present comparisons with 2SLAQ and COMBO-17 (photo)redshifts. Crucially, the riz selection coupled with the three to four times improved AAOmega throughput is shown to extend the LRG mean redshift from z=0.55 for 2SLAQ to z=0.681+/-0.005 for riz-selected LRGs. This extended range is vital for maximizing the signal-to-noise ratio for the detection of the baryon acoustic oscillations (BAOs). Furthermore, we show that the amplitude of LRG clustering is s_0_=9.9+/-0.7h^-1^Mpc, as high as that seen in the 2SLAQ LRG Survey. Consistent results for this clustering amplitude are found from the projected and semi-projected correlation functions. This high amplitude is consistent with a long-lived population whose bias evolves as predicted by a simple 'high-peak' model. We conclude that a redshift survey of 360000 LRGs over 3000deg^2^, with an effective volume some four times bigger than previously used to detect BAO with LRGs, is possible with AAOmega in 170 nights.
- ID:
- ivo://CDS.VizieR/J/AJ/123/567
- Title:
- SDSS quasar catalog, I: Early Data Release
- Short Name:
- J/AJ/123/567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of the 3814 objects (3000 discovered by the SDSS) in the initial SDSS public data release that have at least one emission line with a full width at half-maximum larger than 1000 km/s, luminosities brighter than M_I*_=-23, and highly reliable redshifts. The area covered by the catalog is 494{deg}^2^ ; the majority of the objects were found in SDSS commissioning data using a multicolor selection technique. The quasar redshifts range from 0.15 to 5.03. For each object the catalog presents positions accurate to better than 0.2" rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.05 mag, radio and X-ray emission properties, and information on the morphology and selection method. Calibrated spectra of all objects in the catalog, covering the wavelength region 3800-9200{AA} at a spectral resolution of 1800-2100, are also available. Since the quasars were selected during the commissioning period, a time when the quasar selection algorithm was undergoing frequent revisions, the sample is not homogeneous and is not intended for statistical analysis.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2579
- Title:
- SDSS quasar catalog. II. First data release
- Short Name:
- J/AJ/126/2579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the second edition of the Sloan Digital Sky Survey (SDSS) Quasar Catalog. The catalog consists of the 16,713 objects in the SDSS First Data Release that have luminosities larger than M_i_=-22 (in a cosmology with H_0_=70km/s/Mpc, {Omega}_M_=0.3, and {Omega}_{Lambda}_=0.7), have at least one emission line with FWHM larger than 1000km/s, and have highly reliable redshifts. The area covered by the catalog is 1360{deg}^2^. The quasar redshifts range from 0.08 to 5.41, with a median value of 1.43. For each object, the catalog presents positions accurate to better than 0.2" rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03mag, and information on the morphology and selection method. The catalog also contains some radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. Calibrated digital spectra of all objects in the catalog, covering the wavelength region 3800-9200{AA} at a spectral resolution of 1800-2100, are available. This publication supersedes the first SDSS Quasar Catalog (2002, Cat. <J/AJ/123/567>), which was based on material from the SDSS Early Data Release. A summary of corrections to current quasar databases is also provided. The majority of the objects were found in SDSS commissioning data using a multicolor selection technique. Since the quasar selection algorithm was undergoing testing during the entire observational period covered by this catalog, care must be taken when assembling samples from the catalog for use in statistical studies. A total of 15786 objects (94%) in the catalog were discovered by the SDSS; 12173 of the SDSS discoveries are reported here for the first time. Included in the new discoveries are five quasars brighter than i=16.0 and 17 quasars with redshifts larger than 4.5.
- ID:
- ivo://CDS.VizieR/VII/243
- Title:
- SDSS quasar catalog. III.
- Short Name:
- VII/243
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog consists of the 46,420 objects in the SDSS Third Data Release that have luminosities larger than M_i_=-22 (in a cosmology with Ho=70km/s/Mpc, {Omega}_M_=0.3 and {Omega}_{Lambda}_=0.7), have at least one emission line with FWHM larger than 1000 km/s or are unambiguously broad absorption line quasars, are fainter than i=15.0 and have highly reliable redshifts. The area covered by the catalog is about 4188 deg^2^. The quasar redshifts range from 0.08 to 5.41, with a median value of 1.47; the high-redshift sample includes 520 quasars at redshifts greater than four, of which 17 are at redshifts greater than five. For each object the catalog presents positions accurate to better than 0.2" rms per coordinate, five-band (ugriz) CCD-based photometry with typical accuracy of 0.03 mag, and information on the morphology and selection method. The catalog also contains radio, near-infrared, and X-ray emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra cover the wavelength region 3800-9200{AA} at a spectral resolution of about 2000; the spectra can be retrieved from the public database using the information provided in the catalog. A total of 44,221 objects in the catalog were discovered by the SDSS; 28,400 of the SDSS discoveries are reported here for the first time.
- ID:
- ivo://CDS.VizieR/VII/289
- Title:
- SDSS quasar catalog, sixteenth data release (DR16Q)
- Short Name:
- VII/289
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the final Sloan Digital Sky Survey IV (SDSS-IV) quasar catalog from Data Release 16 of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). This catalog comprises the largest selection of spectroscopically confirmed quasars to date. The full catalog includes two subcatalogs (the current versions are DR16Q_v4 and DR16Q_Superset_v3 at http://data.sdss.org/sas/dr16/eboss/qso/DR16Q): a "superset" of all SDSS-IV/eBOSS objects targeted as quasars containing 1,440,615 observations and a quasar-only catalog containing 750,414 quasars, including 225,082 new quasars appearing in an SDSS data release for the first time, as well as known quasars from SDSS-I/II/III. We present automated identification and redshift information for these quasars alongside data from visual inspections for 320,161 spectra. The quasar-only catalog is estimated to be 99.8% complete with 0.3%-1.3% contamination. Automated and visual inspection redshifts are supplemented by redshifts derived via principal component analysis and emission lines. We include emission-line redshifts for H{alpha}, H{beta}, MgII, CIII], CIV, and Ly{alpha}. Identification and key characteristics generated by automated algorithms are presented for 99,856 broad absorption-line quasars and 35,686 damped Lyman alpha quasars. In addition to SDSS photometric data, we also present multiwavelength data for quasars from the Galaxy Evolution Explorer, UKIDSS, the Wide-field Infrared Survey Explorer, FIRST, ROSAT/2RXS, XMM-Newton, and Gaia.
