- 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^.
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Search Results
422. XBACs, the sample
- ID:
- ivo://CDS.VizieR/J/MNRAS/281/799
- Title:
- XBACs, the sample
- Short Name:
- J/MNRAS/281/799
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an essentially complete, all-sky, X-ray flux-limited sample of 242 Abell clusters of galaxies (six of which are double) compiled from ROSAT All-Sky Survey data. Our sample is uncontaminated in the sense that systems featuring prominent X-ray point sources such as AGN or foreground stars have been removed. The sample is limited to high Galactic latitudes (|b|>=20{deg}), the nominal redshift range of the ACO catalogue of z<=0.2, and X-ray fluxes above 5.0x10^-12^erg/cm^2^/s in the 0.1-2.4keV band. Owing to the X-ray flux limit, our sample consists, at intermediate and high redshifts, exclusively of very X-ray-luminous clusters. Since the latter tend to be also optically rich, the sample is not affected by the optical selection effects and, in particular, not by the volume incompleteness known to be present in the Abell and ACO catalogues for richness class 0 and 1 clusters. Our sample is the largest X-ray flux-limited sample of galaxy clusters compiled to date and will allow investigations of unprecedented statistical quality into the properties and distribution of rich clusters in the local Universe.
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/662
- Title:
- X-CLASS/GROND catalogue
- Short Name:
- J/MNRAS/468/662
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The XMM Cluster Archive Super Survey (X-CLASS) is a serendipitously detected X-ray-selected sample of 845 galaxy clusters based on 2774 XMM archival observations and covering an approximately 90deg^2^ spread across the high-Galactic latitude (|b|>20{deg}) sky. The primary goal of this survey is to produce a well-selected sample of galaxy clusters on which cosmological analyses can be performed. This paper presents the photometric redshift follow-up of a high signal-to-noise ratio subset of 265 of these clusters with declination {delta}<+20{deg} with Gamma-Ray Burst Optical and Near-Infrared Detector (GROND), a 7-channel (grizJHK) simultaneous imager on the MPG 2.2-m telescope at the ESO La Silla Observatory. We use a newly developed technique based on the red sequence colour-redshift relation, enhanced with information coming from the X-ray detection to provide photometric redshifts for this sample. We determine photometric redshifts for 232 clusters, finding a median redshift of z=0.39 with an accuracy of {Delta}z=0.02(1+z) when compared to a sample of 76 spectroscopically confirmed clusters. We also compute X-ray luminosities for the entire sample and find a median bolometric luminosity of 7.2x10^43^erg/s and a median temperature of 2.9 keV. We compare our results to those of the XMM-XCS and XMM-XXL surveys, finding good agreement in both samples. The X-CLASS catalogue is available online at http://xmm-lss.in2p3.fr:8080/l4sdb/.
- ID:
- ivo://CDS.VizieR/J/MNRAS/453/1136
- Title:
- XDF CHEF photometric catalogue
- Short Name:
- J/MNRAS/453/1136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometric redshifts, which have become the cornerstone of several of the largest astronomical surveys like PanStarrs, DES, J-PAS and LSST, require precise measurements of galaxy photometry in different bands using a consistent physical aperture. This is not trivial, due to the variation in the shape and width of the point spread function (PSF) introduced by wavelength differences, instrument positions and atmospheric conditions. Current methods to correct for this effect rely on a detailed knowledge of PSF characteristics as a function of the survey coordinates, which can be difficult due to the relative paucity of stars tracking the PSF behaviour. Here we show that it is possible to measure accurate, consistent multicolour photometry without knowing the shape of the PSF. The Chebyshev-Fourier functions (CHEFs) can fit the observed profile of each object and produce high signal-to-noise integrated flux measurements unaffected by the PSF. These total fluxes, which encompass all the galaxy populations, are much more useful for galaxy evolution studies than aperture photometry. We compare the total magnitudes and colours obtained using our software to traditional photometry with SExtractor, using real data from the COSMOS survey and the Hubble Ultra-Deep Field (HUDF). We also apply the CHEF technique to the recently published eXtreme Deep Field (XDF) and compare the results to those from ColorPro on the HUDF. We produce a photometric catalogue with 35732 sources (10823 with signal-to-noise ratio >=5), reaching a photometric redshift precision of 2 per cent due to the extraordinary depth and wavelength coverage of the eXtreme Deep Field images.
425. XMM/CFDS catalogue
- ID:
- ivo://CDS.VizieR/J/MNRAS/350/785
- Title:
- XMM/CFDS catalogue
- Short Name:
- J/MNRAS/350/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the X-ray source catalogues for the XMM surveys of the 3-h and 14-h (also known as the Groth Strip) Canada-France Redshift Survey fields (0.5-10keV flux range ~2x10^-15^-10^-13^erg/cm^2^/s). We use a subset of the XMM sources, which have Chandra positions, to determine the best method of obtaining optical identifications of sources with only XMM positions. We find optical identifications for 79 per cent of the XMM sources for which there are deep optical images. The sources without optical identifications are likely to be optically fainter and have higher redshifts than the sources with identifications. We have estimated 'photometric redshifts' for the identified sources, calibrating our method using ~200 galaxies in the fields with spectroscopic redshifts. We find that the redshift distribution has a strong peak at z~0.7.
- ID:
- ivo://CDS.VizieR/J/PAZh/42/313
- Title:
- 3XMM-DR4 QSO candidates at 3<z<5.5
- Short Name:
- J/PAZh/42/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of quasar candidates at redshifts 3<z<5.5 is presented. These candidates have been selected among X-ray sources in the XMM-Newton Serendipitous Source Catalog (3XMM-DR4) in the 0.5-2keV band, located at high galactic latitudes |b|>20deg in the Sloan Digital Sky Survey (SDSS) area. The total overlapping area is about 300 sq. deg. The SDSS, 2MASS and WISE photometric catalogs were used. Only SDSS point sources were considered. X-ray sources having an optical counterpart with magnitude error in SDSS z band of less than 0.2 and color i-z<0.6 were chosen. Their photometric redshifts were determined with the EAZY code using a library of spectral templates. A sample of quasar candidates with photometric redshifts in the range 2.75<z<5.5 has been composed. Objects whose spectral energy distributions are better described by stellar templates have been excluded. The selection completeness of known quasars is about 80%. The normalized median absolute deviation of the differences between the photometric and spectroscopic redshifts of known quasars is 0.07 (with 9% outliers). The sky density of quasar candidates in our sample is 1.5 times that of the spectroscopic SDSS sample in the same fields. Follow-up spectroscopy should clarify the purity of the sample.
- ID:
- ivo://CDS.VizieR/J/MNRAS/456/4488
- Title:
- XQ-100 survey neutral gas
- Short Name:
- J/MNRAS/456/4488
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a sample of 38 intervening damped Lyman {alpha} (DLA) systems identified towards 100 z>3.5 quasars, observed during the XQ-100 survey. The XQ-100 DLA sample is combined with major DLA surveys in the literature. The final combined sample consists of 742 DLAs over a redshift range approximately 1.6<z_abs_<5.0. We develop a novel technique for computing {Omega}_HI_^DLA^ as a continuous function of redshift, and we thoroughly assess and quantify the sources of error therein, including fitting errors and incomplete sampling of the high column density end of the column density distribution function. There is a statistically significant redshift evolution in {Omega}_HI_^DLA^ (>=3{sigma}) from z~2 to z~5. In order to make a complete assessment of the redshift evolution of {Omega}_HI_, we combine our high-redshift DLA sample with absorption surveys at intermediate redshift and 21-cm emission line surveys of the local universe. Although {Omega}_HI_^DLA^, and hence its redshift evolution, remains uncertain in the intermediate-redshift regime (0.1<z_abs_<1.6), we find that the combination of high-redshift data with 21-cm surveys of the local universe all yield a statistically significant evolution in {Omega}_HI_ from z~0 to z~5 (>=3{sigma}). Despite its statistical significance, the magnitude of the evolution is small: a linear regression fit between {Omega}_HI_ and z yields a typical slope of ~0.17x10^-3^, corresponding to a factor of ~4 decrease in {Omega}_HI_ between z=5 and z=0.
- ID:
- ivo://CDS.VizieR/J/MNRAS/462/3285
- Title:
- XQ-100. X-shooter quasar spectra
- Short Name:
- J/MNRAS/462/3285
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We statistically study the physical properties of a sample of narrow absorption line (NAL) systems looking for empirical evidences to distinguish between intrinsic and intervening NALs without taking into account any a priori definition or velocity cut-off. We analyse the spectra of 100 quasars with 3.5<z_em_<4.5, observed with X-shooter/Very Large Telescope in the context of the XQ-100 Legacy Survey. We detect an ~8{sigma} excess in the CIV number density within 10000km/s of the quasar emission redshift with respect to the random occurrence of NALs. This excess does not show a dependence on the quasar bolometric luminosity and it is not due to the redshift evolution of NALs. It extends far beyond the standard 5000km/s cut-off traditionally defined for associated absorption lines. We propose to modify this definition, extending the threshold to 10000km/s when weak absorbers (equivalent width <0.2{AA}) are also considered. We infer NV is the ion that better traces the effects of the quasar ionization field, offering the best statistical tool to identify intrinsic systems. Following this criterion, we estimate that the fraction of quasars in our sample hosting an intrinsic NAL system is 33 per cent. Lastly, we compare the properties of the material along the quasar line of sight, derived from our sample, with results based on close quasar pairs investigating the transverse direction. We find a deficiency of cool gas (traced by C II) along the line of sight connected to the quasar host galaxy, in contrast with what is observed in the transverse direction.
- ID:
- ivo://CDS.VizieR/J/MNRAS/379/260
- Title:
- X-ray clusters with radio emission
- Short Name:
- J/MNRAS/379/260
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By combining the REFLEX and NORAS cluster data sets with the NVSS radio catalogue, we obtain a sample of 145, z<0.3, X-ray-selected clusters brighter than 3x10^-12^erg/s/cm^-2^ that show a central radio emission above 3mJy. For virial masses M_vir_<10^14.5^M_{sun}_, 11 clusters out of 12 (corresponding to 92 per cent of the systems) are inhabited by a central radio source.
- ID:
- ivo://CDS.VizieR/J/MNRAS/428/3089
- Title:
- X-ray properties of BzK-selected galaxies
- Short Name:
- J/MNRAS/428/3089
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the X-ray properties of BzK-selected galaxies at z~2 using deep X-ray data in the Chandra Deep Field-South (CDFS) and Chandra Deep Field-North (CDFN). A subset of these BzK galaxies have been proposed as Compton-thick active galactic nucleus (AGN) candidates based on a high ratio of infrared (IR) to ultraviolet (UV) star formation rates (SFRs). With the benefit of deep 24{mu}m observations, our sample of these IR-excess galaxies is larger than previous studies and combined with the deepest X-ray data yield new insights into the population. We identify 701 and 534 star-forming BzK galaxies (sBzK galaxies) in the range z=1.2-3.0 in CDFS and CDFN, respectively. Of these we directly detect in X-rays 49 sBzK galaxies in CDFS and 32 sBzK galaxies in CDFN.
