- ID:
- ivo://CDS.VizieR/J/ApJS/247/43
- Title:
- WWFI g'-band obs. of bright cluster galaxies
- Short Name:
- J/ApJS/247/43
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of 170 local (z<~0.08) galaxy clusters in the northern hemisphere have been obtained with the Wendelstein Telescope Wide Field Imager (WWFI). We correct for systematic effects such as point-spread function broadening, foreground star contamination, relative bias offsets, and charge persistence. Background inhomogeneities induced by scattered light are reduced down to {Delta}SB>31 g' mag/arcsec^2^ by large dithering and subtraction of night-sky flats. Residual background inhomogeneities brighter than SB_{sigma}_<27.6 g' mag/arcsec^2^ caused by galactic cirrus are detected in front of 23% of the clusters. However, the large field of view allows discrimination between accretion signatures and galactic cirrus. We detect accretion signatures in the form of tidal streams in 22%, shells in 9.4%, and multiple nuclei in 47% of the brightest cluster galaxies (BCGs) and find two BCGs in 7% of the clusters. We measure semimajor-axis surface brightness profiles of the BCGs and their surrounding intracluster light (ICL) down to a limiting surface brightness of SB=30 g' mag/arcsec^2^. The spatial resolution in the inner regions is increased by combining the WWFI light profiles with those that we measured from archival Hubble Space Telescope images or deconvolved WWFI images. We find that 71% of the BCG+ICL systems have surface brightness (SB) profiles that are well described by a single Sersic function, whereas 29% require a double Sersic function to obtain a good fit. We find that BCGs have scaling relations that differ markedly from those of normal ellipticals, likely due to their indistinguishable embedding in the ICL.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/568/A5
- Title:
- XDCP J0044.0-2033 J and Ks images
- Short Name:
- J/A+A/568/A5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent observational progress has enabled the detection of galaxy clusters and groups out to very high redshifts and for the first time allows detailed studies of galaxy population properties in these densest environments in what was formerly known as the "redshift desert" at z>1.5. We aim to investigate various galaxy population properties of the massive X-ray luminous galaxy cluster XDCP J0044.0-2033 at z=1.58, which constitutes the most extreme currently known matter-density peak at this redshift. We analyzed deep VLT/HAWK-I near-infrared data with an image quality of 0.5" and limiting Vega magnitudes (50% completeness) of 24.2 in J- and 22.8 in the Ks band, complemented by similarly deep Subaru imaging in i and V, Spitzer observations at 4.5um, and new spectroscopic observations with VLT/FORS 2.
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJS/181/444
- Title:
- X-emitting stars identified from the RASS/SDSS
- Short Name:
- J/ApJS/181/444
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The ROSAT All-Sky Survey (RASS) was the first imaging X-ray survey of the entire sky. Combining the RASS Bright and Faint Source Catalogs (Cat. <IX/10>, 1RXS and <IX/29>) yields an average of about three X-ray sources per square degree. However, while X-ray source counterparts are known to range from distant quasars to nearby M dwarfs, the RASS data alone are often insufficient to determine the nature of an X-ray source. As a result, large-scale follow-up programs are required to construct samples of known X-ray emitters. We use optical data produced by the Sloan Digital Sky Survey (SDSS) to identify 709 stellar X-ray emitters cataloged in the RASS and falling within the SDSS Data Release 1 footprint. Most of these are bright stars with coronal X-ray emission unsuitable for SDSS spectroscopy, which is designed for fainter objects (g>15[mag]). Instead, we use SDSS photometry, correlations with the Two Micron All Sky Survey and other catalogs, and spectroscopy from the Apache Point Observatory 3.5m telescope to identify these stellar X-ray counterparts. Our sample of 707 X-ray-emitting F, G, K, and M stars is one of the largest X-ray-selected samples of such stars. We identify 17 new X-ray-emitting DA (hydrogen) WDs, of which three are newly identified WDs. We report on follow-up observations of three candidate cool X-ray-emitting WDs (one DA and two DB (helium) WDs); we have not confirmed X-ray emission from these WDs.
6045. 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/A+A/527/A126
- Title:
- 2XMMi/SDSS DR7 cross-correlation
- Short Name:
- J/A+A/527/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Survey Science Centre of the XMM-Newton satellite released the first incremental version of the 2XMM catalogue in August 2008. Containing more than 220000 X-ray sources, the 2XMMi was at that time the largest catalogue of X-ray sources ever published and thus constitutes an unprecedented resource for studying the high-energy properties of various classes of X-ray emitters such as AGN and stars. Thanks to the high throughput of the EPIC cameras on board XMM-Newton accurate positions, fluxes, and hardness ratios are available for a substantial fraction of the X-ray detections. The advent of the 7th release of the Sloan Digital Sky Survey offers the opportunity to cross-match two major surveys and extend the spectral energy distribution of many 2XMMi sources towards the optical bands. This implies building extensive homogeneous samples with a statistically controlled rate of spurious matches and completeness. We here present a cross-matching algorithm based on the classical likelihood ratio estimator. The method developed has the advantage of providing true probabilities of identifications without resorting to heavy Monte-Carlo simulations.
- ID:
- ivo://CDS.VizieR/J/A+A/490/879
- Title:
- XMM-LSS field optical identifications
- Short Name:
- J/A+A/490/879
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The XMM-Large Scale Structure survey field (XMM-LSS) is an extragalactic window surveyed in the X-ray with the XMM-Newton satellite. It has also been observed in the optical with the Canada-France Hawaii Telescope (CFHTLS survey), and in the infrared with the Spitzer Space Telescope (SWIRE survey). These surveys have been carried out to study the structure and evolution of both baryonic and dark matter on cosmological scales. In two previous papers, we presented deep low frequency radio surveys of the XMM-LSS field, with limiting flux density levels of ~4 and ~1.5mJy/beam at 325 and 610MHz respectively (5{sigma}). These radio surveys were motivated by the need to understand the various connections between the host galaxies of radio sources and their environments. In this paper, we identify optical counterparts to the low frequency radio sources, using the CFHTLS optical catalogue and images, that have an i-band limiting magnitude of i_AB_~25.
- ID:
- ivo://CDS.VizieR/J/A+A/418/841
- Title:
- XMM-Newton observations of N11 in the LMC
- Short Name:
- J/A+A/418/841
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the XMM-Newton observatory, we have observed the giant H II region N11 of the LMC. The field includes three OB associations LH9, LH9, and LH13. Our XMM observations included parallel observations with the OM camera that provided us with unique UV and optical photometry of more than 6000 sources. In this paper we present the photometrical data for these sources as well as their cross-identifications with several catalogues.
- ID:
- ivo://CDS.VizieR/J/A+A/476/1191
- Title:
- XMM-Newton serendipitous survey. IV
- Short Name:
- J/A+A/476/1191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- X-ray sources at intermediate fluxes (a few x10^-14^erg/cm^2^/s) with a sky density of ~100deg^-2^ are responsible for a significant fraction of the cosmic X-ray background at various energies below 10keV. The aim of this paper is to provide an unbiased and quantitative description of the X-ray source population at these fluxes and in various X-ray energy bands. We present the XMM-Newton Medium sensitivity Survey (XMS), including a total of 318 X-ray sources found among the serendipitous content of 25 XMM-Newton target fields. The XMS comprises four largely overlapping source samples selected at soft (0.5-2keV), intermediate (0.5-4.5keV), hard (2-10keV) and ultra-hard (4.5-7.5keV) bands, the first three of them being flux-limited.
