- ID:
- ivo://CDS.VizieR/J/ApJ/657/738
- Title:
- SDF galaxies multi-photometry
- Short Name:
- J/ApJ/657/738
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- SDF (Subaru Deep Field) line-emitting galaxies in four narrow-band filters at low and intermediate redshifts are presented. Broadband colors, follow-up optical spectroscopy, and multiple NB filters are used to distinguish H{alpha}, [OII], and [OIII] emitters at z=0.07-1.47 to construct their LFs. These LFs are derived down to faint magnitudes, allowing for an accurate determination of the faint-end slope. With a large (N~200) sample for each redshift interval, a Schechter profile is fitted to each LF.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/144/17
- Title:
- SDSS and CSP ugri photometry of 9 type Ia supernova
- Short Name:
- J/AJ/144/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Consistency between Carnegie Supernova Project (CSP) and SDSS-II Supernova Survey ugri measurements has been evaluated by comparing Sloan Digital Sky Survey (SDSS) and CSP photometry for nine spectroscopically confirmed Type Ia supernova observed contemporaneously by both programs. The CSP data were transformed into the SDSS photometric system. Sources of systematic uncertainty have been identified, quantified, and shown to be at or below the 0.023mag level in all bands. When all photometry for a given band is combined, we find average magnitude differences of equal to or less than 0.011mag in ugri, with rms scatter ranging from 0.043 to 0.077mag. The u-band agreement is promising, with the caveat that only four of the nine supernovae are well observed in u and these four exhibit an 0.038mag supernova-to-supernova scatter in this filter.
- ID:
- ivo://CDS.VizieR/J/AN/329/790
- Title:
- SDSS and Johnson-Cousins photometry of F-K stars
- Short Name:
- J/AN/329/790
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For an understanding of Galactic stellar populations in the SDSS filter system well defined stellar samples are needed. The nearby stars provide a complete stellar sample representative for the thin disc population. We compare the filter transformations of different authors applied to the main sequence stars from F to K dwarfs to SDSS filter system and discuss the properties of the main sequence. The location of the mean main sequence in colour-magnitude diagrams is very sensitive to systematic differences in the filter transformation. A comparison with fiducial sequences of star clusters observed in g', r', and i' show good agreement. Theoretical isochrones from Padua and from Dartmouth have still some problems, especially in the (r-i) colours.
- ID:
- ivo://CDS.VizieR/J/AJ/135/785
- Title:
- SDSS-DR5 low-mass star spectroscopic sample
- Short Name:
- J/AJ/135/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic analysis of over 38000 low-mass stars from the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5). Analysis of this unprecedentedly large sample confirms the previously detected decrease in the fraction of magnetically active stars (as traced by H{alpha} emission) as a function of vertical distance from the Galactic Plane. The magnitude and slope of this effect varies as a function of spectral type. Using simple 1-D dynamical models, we demonstrate that the drop in activity fraction can be explained by thin disk dynamical heating and a rapid decrease in magnetic activity. The timescale for this rapid activity decrease changes according to the spectral type. By comparing our data to the simulations, we calibrate the age-activity relation at each M dwarf spectral type. We also present evidence for a possible decrease in the metallicity as a function of height above the Galactic Plane. In addition to our activity analysis, we provide line measurements, molecular band indices, colors, radial velocities, 3-D space motions and mean properties as a function of spectral type for the SDSS DR5 low-mass star sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/1274
- Title:
- SDSS-II SN Ia BVRI photometry
- Short Name:
- J/MNRAS/465/1274
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have analysed multiband light curves of 328 intermediate-redshift (0.05<=z<0.24) Type Ia supernovae (SNe Ia) observed by the Sloan Digital Sky Survey-II Supernova Survey. The multiband light curves were parametrized by using the multiband stretch method, which can simply parametrize light-curve shapes and peak brightness without dust extinction models. We found that most of the SNe Ia that appeared in red host galaxies (u-r>2.5) do not have a broad light-curve width and the SNe Ia that appeared in blue host galaxies (u-r<2.0) have a variety of light-curve widths. The Kolmogorov-Smirnov test shows that the colour distribution of SNe Ia appearing in red/blue host galaxies is different (a significance level of 99.9 per cent). We also investigate the extinction law of host galaxy dust. As a result, we find that the value of Rv derived from SNe Ia with medium light-curve widths is consistent with the standard Galactic value, whereas the value of Rv derived from SNe Ia that appear in red host galaxies becomes significantly smaller. These results indicate that there may be two types of SNe Ia with different intrinsic colours, and that they are obscured by host galaxy dust with two different properties.
- ID:
- ivo://CDS.VizieR/J/MNRAS/465/1831
- Title:
- SDSS-IV eBOSS ELG UgrizW photometry
- Short Name:
- J/MNRAS/465/1831
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present two wide-field catalogues of photometrically selected emission line galaxies (ELGs) at z~=0.8 covering about 2800deg^2^ over the south galactic cap. The catalogues were obtained using a Fisher discriminant technique described in a companion paper. The two catalogues differ by the imaging used to define the Fisher discriminant: the first catalogue includes imaging from the Sloan Digital Sky Survey and the Wide-field InfraredSurvey Explorer, the second also includes information from the South Galactic Cap U-band Sky Survey. Containing respectively 560045 and 615601 objects, they represent the largest ELG catalogues available today and were designed for the ELG programme of the extended Baryon Oscillation Spectroscopic Survey (eBOSS). We study potential sources of systematic variation in the angular distribution of the selected ELGs due to fluctuations of the observational parameters. We model the influence of the observational parameters using a multivariate regression and implement a weighting scheme which allows effective removal of all of the systematic errors induced by the observational parameters. We show that fluctuations in the imaging zero-points of the photometric bands have minor impact on the angular distribution of objects in our catalogues. We compute the angular clustering of both catalogues and show that our weighting procedure effectively removes spurious clustering on large scales. We fit a model to the small-scale angular clustering, showing that the selections have similar biases of 1.35/Da(z) and 1.28/Da(z). Both catalogues are publicly available.
- ID:
- ivo://CDS.VizieR/J/A+A/636/A97
- Title:
- SDSS-IV/SPIDERS X-ray PS Spectroscopic Catalog
- Short Name:
- J/A+A/636/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We look to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV programme aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources. We describe the SPIDERS X-ray Point Source Spectroscopic Catalogue, considering its store of 11092 observed spectra drawn from a parent sample of 14759 ROSAT and XMM sources over an area of 5129deg^2^ covered in SDSS-IV by the eBOSS survey. This programme represents the largest systematic spectroscopic observation of an X-ray selected sample. A total of 10970 (98.9%) of the observed objects are classified and 10849 (97.8%) have secure redshifts. The majority of the spectra (10070 objects) are active galactic nuclei (AGN), 522 are cluster galaxies, and 294 are stars. The observed AGN redshift distribution is in good agreement with simulations based on empirical models for AGN activation and duty cycle. Forming composite spectra of type 1 AGN as a function of the mass and accretion rate of their black holes reveals systematic differences in the H-beta emission line profiles. This study paves the way for systematic spectroscopic observations of sources that are potentially to be discovered in the upcoming eROSITA survey over a large section of the sky.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/3430
- Title:
- SDSS-2MASS-WISE stellar colour locus
- Short Name:
- J/MNRAS/440/3430
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the fiducial main-sequence stellar locus traced by 10 photometric colours observed by Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey (2MASS), and Wide-field Infrared Survey Explorer} (WISE). Median colours are determined using 1052 793 stars with r-band extinction less than 0.125. We use this locus to measure the dust extinction curve relative to the r band, which is consistent with previous measurements in the SDSS and 2MASS bands. The WISE band extinction coefficients are larger than predicted by standard extinction models. Using 13 lines of sight, we find variations in the extinction curve in H, Ks, and WISE bandpasses. Relative extinction decreases towards Galactic anticentre, in agreement with prior studies. Relative extinction increases with Galactic latitude, in contrast to previous observations. This indicates a universal mid-IR extinction law does not exist due to variations in dust grain size and chemistry with Galactocentric position. A preliminary search for outliers due to warm circumstellar dust is also presented, using stars with high signal-to-noise ratio in the W3 band. We find 199 such outliers, identified by excess emission in Ks-W3. Inspection of SDSS images for these outliers reveals a large number of contaminants due to nearby galaxies. Six sources appear to be genuine dust candidates, yielding a fraction of systems with infrared excess of 0.12+/-0.05 per cent.
2569. SDSS M, L, and T dwarfs
- ID:
- ivo://CDS.VizieR/J/AJ/123/3409
- Title:
- SDSS M, L, and T dwarfs
- Short Name:
- J/AJ/123/3409
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An extensive sample of M, L, and T dwarfs identified in the Sloan Digital Sky Survey (SDSS) has been compiled. The sample of 718 dwarfs includes 677 new objects (629 M dwarfs and 48 L dwarfs), together with 41 that have been previously published. All new objects and some of the previously published ones have new optical spectra obtained either with the SDSS spectrographs or with the Apache Point Observatory 3.5 m ARC telescope. Spectral types and SDSS colors are available for all objects; approximately 35% also have near-infrared magnitudes measured by 2MASS (Two Micron All Sky Survey) or on the Mauna Kea system. We use this sample to characterize the color-spectral type and color-color relations of late-type dwarfs in the SDSS filters and to derive spectroscopic and photometric parallax relations for use in future studies of the luminosity and mass functions based on SDSS data. We find that the i*-z* and i*-J colors provide good spectral type and absolute magnitude (Mi*) estimates for M and L dwarfs. Our distance estimates for the current sample indicate that SDSS is finding early M dwarfs out to ~1.5kpc, L dwarfs to ~100pc, and T dwarfs to ~20pc. The T dwarf photometric data show large scatter and are therefore less reliable for spectral type and distance estimation.
- ID:
- ivo://CDS.VizieR/J/AJ/143/119
- Title:
- SDSS Quasar Lens Search. V. Final catalog
- Short Name:
- J/AJ/143/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the final statistical sample of lensed quasars from the Sloan Digital Sky Survey (SDSS) Quasar Lens Search (SQLS). The well-defined statistical lens sample consists of 26 lensed quasars brighter than i=19.1 and in the redshift range of 0.6<z<2.2 selected from 50826 spectroscopically confirmed quasars in the SDSS Data Release 7 (DR7), where we restrict the image separation range to 1"<{theta}<20" and the i-band magnitude differences in two images to be smaller than 1.25mag. The SDSS-DR7 quasar catalog also contains 36 additional lenses identified with various techniques. In addition to these lensed quasars, we have identified 81 pairs of quasars from follow-up spectroscopy, 26 of which are physically associated binary quasars. The statistical lens sample covers a wide range of image separations, redshifts, and magnitudes, and therefore is suitable for systematic studies of cosmological parameters and surveys of the structure and evolution of galaxies and quasars.
