- ID:
- ivo://CDS.VizieR/J/MNRAS/448/2260
- Title:
- White dwarf candidates in SDSS DR10
- Short Name:
- J/MNRAS/448/2260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a method which uses cuts in colour-colour and reduced proper motion-colour space to select white dwarfs without the recourse to spectroscopy while allowing an adjustable compromise between completeness and efficiency. Rather than just producing a list of white dwarf candidates, our method calculates a probability of being a white dwarf (P_WD_) for any object with available multiband photometry and proper motion. We applied this method to all objects in the Sloan Digital Sky Survey (SDSS) Data Release 10 (DR10) photometric footprint and to a few selected sources in DR7 which did not have reliable photometry in DR9 or DR10. This application results in a sample of 61 969 DR10 and 3799 DR7 photometric sources with calculated P_WD_ from which it is possible to select a sample of ~23000 high-fidelity white dwarf candidates with T_eff_>~7000K and g<=19. This sample contains over 14000 high confidence white dwarfs candidates which have not yet received spectroscopic follow-up. These numbers show that, to date, the spectroscopic coverage of white dwarfs in the SDSS photometric footprint is, on average, only ~40 percent complete. While we describe here in detail the application of our selection to the SDSS catalogue, the same method could easily be applied to other multicolour, large area surveys. We also publish a list of 8701 bright (g<=19) white dwarfs with SDSS spectroscopy, of which 1781 are new identifications in DR9/DR10.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/452/765
- Title:
- White dwarf candidates using LAMOST DR3
- Short Name:
- J/MNRAS/452/765
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In previous work by Gentile Fusillo et al., we developed a selection method for white dwarf candidates which makes use of photometry, colours and proper motions to calculate a probability of being a white dwarf (P_WD_). The application of our method to the Sloan Digital Sky Survey (SDSS) data release 10 resulted in =~ 66000 photometrically selected objects with a derived P_WD_, approximately =~21000 of which are high-confidence white dwarf candidates. Here, we present an independent test of our selection method based on a sample of spectroscopically confirmed white dwarfs from the Large Sky Area Multi-Fiber Spectroscopic Telescope (LAMOST) survey. We do this by cross-matching all our =~66000 SDSS photometric white dwarf candidates with the over 4 million spectra available in the third data release of LAMOST. This results in 1673 white dwarf candidates with no previous SDSS spectroscopy, but with available LAMOST spectra. Among these objects, we identify 309 genuine white dwarfs. We find that our P_WD_ can efficiently discriminate between confirmed LAMOST white dwarfs and contaminants. Our white dwarf candidate selection method can be applied to any multiband photometric survey and in this work we conclusively confirm its reliability in selecting white dwarfs without recourse to spectroscopy. We also discuss the spectroscopic completeness of white dwarfs in LAMOST, as well as deriving effective temperatures, surface gravities and masses for the hydrogen-rich atmosphere white dwarfs in the newly identified LAMOST sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/416/927
- Title:
- Wide-field optical imaging of 4 fields
- Short Name:
- J/MNRAS/416/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present u-, g-, r-, i- and z-band optical images and associated catalogues taken primarily with the Isaac Newton Telescope Wide Field Camera on the European Large Area ISO Survey (ELAIS) N1 and N2, First Look Survey and Lockman Hole fields comprising a total of 1000h of integration time over 80deg^2^ and approximately 4.3 million objects. In this paper we outline the observations and data processing and characterize the completeness, reliability, photometric and astrometric accuracy of this data set. All images have been photometrically calibrated using the Sloan Digital Sky Survey and a uniform and homogeneous data set is composed over all the observed fields. Magnitude limits are u, g, r, i, z of 23.9, 24.5, 24.0, 23.3, 22.0 (AB, 5{sigma}). These data have been used for optical identification of past and ongoing projects including the surveys ELAIS, Spitzer Wide-Area Infrared Extragalactic Survey, Spitzer Extragalactic Representative Volume Survey and Herschel Multi-tiered Extragalactic Survey.
- ID:
- ivo://CDS.VizieR/J/ApJ/819/1
- Title:
- Wide-field photometry of the GC Palomar 5
- Short Name:
- J/ApJ/819/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of wide-field photometric surveys of the Palomar 5 globular cluster and its stellar stream, based on g- and r-band measures together with narrow-band DDO 51 photometry. In this first study, we use the deep (g, r) data to measure the incidence of gaps and peaks along the stream. Examining the star-counts profile of the stream plus contaminating populations, we find no evidence for significant underdensities, and find only a single significant overdensity. This is at odds with earlier studies based on matched-filter maps derived from shallower SDSS data if the contaminating population possesses plausible spatial properties. The lack of substantial substructure along the stream may be used in future dynamical simulations to examine the incidence of dark matter sub-halos in the Galactic halo. We also present a measurement of the relative distances along the stream, which we use to create the deepest wide-field map of this system to date. Universe}
- ID:
- ivo://CDS.VizieR/J/AJ/156/137
- Title:
- Wide-orbit Exoplanet search with IR Direct imaging
- Short Name:
- J/AJ/156/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results from the Wide-orbit Exoplanet search with InfraRed Direct imaging, or WEIRD, a survey designed to search for Jupiter-like companions on very wide orbits (1000-5000 au) around young stars (<120 Myr) that are known members of moving groups in the solar neighborhood (<70 pc). Companions that share the same age, distance, and metallicity as their host while being on large enough orbits to be studied as "isolated" objects make prime targets for spectroscopic observations, and they are valuable benchmark objects for exoplanet atmosphere models. The search strategy is based on deep imaging in multiple bands across the near-infrared domain. For all 177 objects of our sample, z'_ab_, J, [3.6], and [4.5] images were obtained with CFHT/MegaCam, GEMINI/GMOS, CFHT/WIRCam, GEMINI/Flamingos-2, and Spitzer/IRAC. Using this set of four images per target, we searched for sources with red z'_ab_ and [3.6]-[4.5] colors, typically reaching good completeness down to 2 M_Jup_ companions, while going down to 1 M_Jup_ for some targets, at separations of 1000-5000 au. The search yielded four candidate companions with the expected colors, but they were all rejected through follow-up proper motion observations. Our results constrain the occurrence of 1-13 M_Jup_ planetary-mass companions on orbits with a semimajor axis between 1000 and 5000 au at less than 0.03, with a 95% confidence level.
- ID:
- ivo://CDS.VizieR/J/MNRAS/401/1429
- Title:
- WiggleZ dark energy survey (DR1)
- Short Name:
- J/MNRAS/401/1429
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The WiggleZ Dark Energy Survey is a survey of 240000 emission-line galaxies in the distant Universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The primary aim of the survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at look-back times of 4-8Gyr. The target galaxies are selected using ultraviolet (UV) photometry from the Galaxy Evolution Explorer satellite, with a flux limit of NUV<22.8mag. We also require that the targets are detected at optical wavelengths, specifically in the range 20.0<r<22.5mag. We use the Lyman break method applied to the UV colours, with additional optical colour limits, to select high-redshift galaxies. The galaxies generally have strong emission lines, permitting reliable redshift measurements in relatively short exposure times on the AAT. The median redshift of the galaxies is z_med_=0.6. The redshift range containing 90 per cent of the galaxies is 0.2<z<1.0. The survey will sample a volume of ~1Gpc^3^ over a projected area on the sky of 1000deg^2^, with an average target density of 350deg^-2^.
- ID:
- ivo://CDS.VizieR/J/MNRAS/474/4151
- Title:
- WiggleZ Dark Energy Survey final DR
- Short Name:
- J/MNRAS/474/4151
- Date:
- 02 Mar 2022 00:09:00
- Publisher:
- CDS
- Description:
- The WiggleZ Dark Energy Survey measured the redshifts of over 200000 ultraviolet (UV)-selected (N_UV_<22.8mag) galaxies on the Anglo-Australian Telescope. The survey detected the baryon acoustic oscillation signal in the large-scale distribution of galaxies over the redshift range 0.2<z<1.0, confirming the acceleration of the expansion of the Universe and measuring the rate of structure growth within it. Here, we present the final data release of the survey: a catalogue of 225415 galaxies and individual files of the galaxy spectra. We analyse the emission-line properties of these UV-luminous Lyman-break galaxies by stacking the spectra in bins of luminosity, redshift, and stellar mass. The most luminous (-25mag<M_FUV_< -22mag) galaxies have very broad H{beta} emission from active nuclei, as well as a broad second component to the [OIII] (495.9nm, 500.7nm) doublet lines that is blueshifted by 100km/s, indicating the presence of gas outflows in these galaxies. The composite spectra allow us to detect and measure the temperature-sensitive [OIII] (436.3nm) line and obtain metallicities using the direct method. The metallicities of intermediate stellar mass (8.8<log(M*/M_{sun}_)<10) WiggleZ galaxies are consistent with normal emission-line galaxies at the same masses. In contrast, the metallicities of high stellar mass (10<log(M*/M_{sun}_)<12) WiggleZ galaxies are significantly lower than for normal emission-line galaxies at the same masses. This is not an effect of evolution as the metallicities do not vary with redshift; it is most likely a property specific to the extremely UV-luminous WiggleZ galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/620/A51
- Title:
- WIRCam Ultra Deep Survey photometric catalogs
- Short Name:
- J/A+A/620/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The aim of this paper is to introduce the WIRCam Ultra Deep Survey (WUDS), a near-IR photometric survey carried out at the CFH Telescope in the field of the CFHTLS-D3 field (Groth Strip). WUDS includes four near-IR bands (Y, J, H and Ks) over a field of view of ~400arcmin^2^. The typical depth of WUDS data reaches between ~26.8 in Y and J, and ~26 in H and Ks (AB, 3{sigma} in 1.3" aperture), whereas the corresponding depth of the CFHTLS-D3 images in this region ranges between 28.6 and 29 in ugr, 28.2 in i and 27.1 in z (same S/N and aperture). The area and depth of this survey were specifically tailored to set strong constraints on the cosmic star formation rate and the luminosity function brighter or around L* in the z~6-10 redshift domain, although these data are also useful for a variety of extragalactic projects. This first paper is intended to present the properties of the public WUDS survey in details: catalog building, completeness and depth, number counts, photometric redshifts, and global properties of the galaxy population. We have also concentrated on the selection and characterization of galaxy samples at z~[4.5-7] in this field. For these purposes, we include an adjacent shallower area of ~1260arcmin^2^ in this region, extracted from the WIRCam Deep Survey (WIRDS), and observed in J, H and Ks bands. UV luminosity functions were derived at z~5 and z~6 taking advantage from the fact that WUDS covers a particularly interesting regime at intermediate luminosities, which allows a combined determination of M* and {PHI}* with increased accuracy. Our results on the luminosity function are consistent with a small evolution of both M* and {PHI}* between z=5 and z=6, irrespective of the method used to derive them, either photometric redshifts applied to blindly-selected dropout samples or the classical Lyman Break Galaxy color-preselected samples. Our results lend support to higher {PHI}* determinations at z=6 than usually reported. The selection and combined analysis of different galaxy samples at z>=7 will be presented in a forthcoming paper, as well as the evolution of the UV luminosity function between z~4.5 and 9. WUDS is intended to provide a robust database in the near-IR for the selection of targets for detailed spectroscopic studies, in particular for the EMIR/GTC GOYA Survey.
- ID:
- ivo://CDS.VizieR/II/311
- Title:
- WISE All-Sky Data Release
- Short Name:
- II/311
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Wide-field Infrared Survey Explorer (WISE; see Wright et al. 2010AJ....140.1868W) is a NASA Medium Class Explorer mission that conducted a digital imaging survey of the entire sky in the 3.4, 4.6, 12 and 22um mid-infrared bandpasses (hereafter W1, W2, W3 and W4). WISE will produce and release to the world astronomical and educational communities and general public a digital Image Atlas covering the sky in the four survey bands, and a reliable Source Catalog containing accurate photometry and astrometry for over 300 million objects. The WISE Catalog and Atlas will enable a broad variety of research efforts ranging from the search for the closest stars and brown dwarfs to the most luminous galaxies in the Universe. WISE science data products will serve as an important reference data set for planning observations and interpreting data obtained with future ground and space-borne observatories, such as JWST. WISE was launched on 2009-12-14 from Vandenberg SLC2W.
- ID:
- ivo://CDS.VizieR/J/ApJ/823/59
- Title:
- WISE and 2MASS photometry of M giant stars
- Short Name:
- J/ApJ/823/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a spectroscopically confirmed sample of M giants, M dwarfs, and quasars from the LAMOST survey, we assess how well Wide-field Infrared Survey Explorer (WISE) and Two Micron All Sky Survey color cuts can be used to select M giant stars. The WISE bands are very efficient at separating M giants from M dwarfs, and we present a simple classification that can produce a clean and relatively complete sample of M giants. We derive a new photometric relation to estimate the metallicity for M giants, calibrated using data from the APOGEE survey. We find a strong correlation between the (W1-W2) color and [M/H], where almost all of the scatter is due to photometric uncertainties. We show that previous photometric distance relations, which are mostly based on stellar models, may be biased and devise a new empirical distance relation, investigating trends with metallicity and star formation history. Given these relations, we investigate the properties of M giants in the Sagittarius stream. The offset in the orbital plane between the leading and trailing tails is reproduced, and by identifying distant M giants in the direction of the Galactic anticenter, we confirm that the previously detected debris in the outer halo is the apocenter of the trailing tail. We also find tentative evidence supporting an existing overdensity near the leading tail in the northern Galactic hemisphere, possibly an extension to the trailing tail (so-called Branch C). We have measured the metallicity distribution along the stream, finding a clear metallicity offset between the leading and trailing tails, in agreement with models for the stream formation. We include an online table of M giants to facilitate further studies.