- ID:
- ivo://CDS.VizieR/J/MNRAS/465/302
- Title:
- Lyman continuum leaking AGN in SSA22 field
- Short Name:
- J/MNRAS/465/302
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Subaru/SuprimeCam narrow-band photometry of the SSA22 field reveals the presence of four Lyman continuum (LyC) candidates among a sample of 14 active galactic nuclei (AGNs). Two show offsets and likely have stellar LyCin nature or are foreground contaminants. The remaining two LyC candidates are type I AGN. We argue that the average LyC escape fraction of high-redshift, low-luminosity AGN is not likely to be unity, as often assumed in the literature. From direct measurement we obtain the average LyC-to-UV flux density ratio and ionizing emissivity for a number of AGN classes and find it at least a factor of 2 lower than values obtained assuming f_esc_=1. Comparing to recent Ly{alpha} forest measurements, AGNs at redshift z~3 make up at most ~12 per cent and as little as ~5 per cent of the total ionizing budget. Our results suggest that AGNs are unlikely to dominate the ionization budget of the Universe at high redshifts.
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212. MARD-Y3 catalog
- ID:
- ivo://CDS.VizieR/J/MNRAS/488/739
- Title:
- MARD-Y3 catalog
- Short Name:
- J/MNRAS/488/739
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the MARD-Y3 catalogue of between 1086 and 2171 galaxy clusters (52 per cent and 65 per cent new) produced using multicomponent matched filter (MCMF) follow-up in 5000 deg^2^ of DES-Y3 optical data of the ~20000 overlapping ROSAT All-Sky Survey source catalogue (2RXS) X-ray sources. Optical counterparts are identified as peaks in galaxy richness as a function of redshift along the line of sight towards each 2RXS source within a search region informed by an X-ray prior. All peaks are assigned a probability fcont of being a random superposition. The clusters lie at 0.02<z<1.1 with more than 100 clusters at z>0.5. Residual contamination is 2.6 per cent and 9.6 per cent for the cuts adopted here. For each cluster we present the optical centre, redshift, rest frame X-ray luminosity, M500 mass, coincidence with NWAY infrared sources, and estimators of dynamical state. About ~2 per cent of MARD-Y3 clusters have multiple possible counterparts, the photo-z's are high quality with {sigma}{DELTA}z/(1+z)=0.0046, and ~1 per cent of clusters exhibit evidence of X-ray luminosity boosting from emission by cluster active galactic nuclei. Comparison with other catalogues (MCXC, RM, SPT-SZ, Planck) is performed to test consistency of richness, luminosity, and mass estimates. We measure the MARD-Y3 X-ray luminosity function and compare it to the expectation from a fiducial cosmology and externally calibrated luminosity- and richness-mass relations. Agreement is good, providing evidence that MARD-Y3 has low contamination and can be understood as a simple two step selection - X-ray and then optical - of an underlying cluster population described by the halo mass function.
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/1265
- Title:
- Masses of galaxy clusters
- Short Name:
- J/MNRAS/435/1265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The application to observational data of the generalized scaling relations (gSRs) presented in Ettori et al. (2012MNRAS.420.2058E) is here discussed. We extend further the formalism of the gSR in the self-similar model for X-ray galaxy clusters, showing that for a generic relation M_tot_{prop.to}L^{alpha}^M_g_^{beta}^T^{gamma}^, where L, M_g_ and T are the gas luminosity, mass and temperature, respectively, the values of the slopes lay in the plane 4{alpha}+3{beta}+2{gamma}=3. Using published data set, we show that some projections of the gSR are the most efficient relations, holding among observed physical quantities in the X-ray band, to recover the cluster gravitating mass.
- ID:
- ivo://CDS.VizieR/J/MNRAS/428/1460
- Title:
- Massive early-type galaxies
- Short Name:
- J/MNRAS/428/1460
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Present-day massive galaxies are composed mostly of early-type objects. It is unknown whether this was also the case at higher redshifts. In a hierarchical assembling scenario the morphological content of the massive population is expected to change with time from disc-like objects in the early Universe to spheroid-like galaxies at present. In this paper we have probed this theoretical expectation by compiling a large sample of massive (M_stellar_>=10^11^h^-2^_70_M{sun}) galaxies in the redshift interval 0<z<3. Our sample of 1082 objects comprises 207 local galaxies selected from Sloan Digital Sky Survey plus 875 objects observed with the Hubble Space Telescope belonging to the Palomar Observatory Wide-field InfraRed/DEEP2 and GOODS NICMOS Survey surveys. 639 of our objects have spectroscopic redshifts. Our morphological classification is performed as close as possible to the optical rest frame according to the photometric bands available in our observations both quantitatively (using the Sersic index as a morphological proxy) and qualitatively (by visual inspection). Using both techniques we find an enormous change on the dominant morphological class with cosmic time. The fraction of early-type galaxies among the massive galaxy population has changed from ~20-30 per cent at z~3 to~70 per cent at z=0. Early-type galaxies have been the predominant morphological class for massive galaxies since only z~1.
- ID:
- ivo://CDS.VizieR/J/MNRAS/382/109
- Title:
- Massive galaxies in Extended Groth Strip
- Short Name:
- J/MNRAS/382/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the combined capabilities of the large near-infrared Palomar/DEEP-2 survey, and the superb resolution of the Advanced Camera for Surveys HST camera, we explore the size evolution of 831 very massive galaxies (M*>=10^11^h^-2^_70_M_{sun}_) since z~2. We split our sample according to their light concentration using the Sersic index n. At a given stellar mass, both low (n<2.5) and high (n>2.5) concentrated objects were much smaller in the past than their local massive counterparts. This evolution is particularly strong for the highly concentrated (spheroid like) objects. At z~1.5, massive spheroid-like objects were a factor of 4(+/-0.4) smaller (i.e. almost two orders of magnitudes denser) than those we see today. These small sized, high-mass galaxies do not exist in the nearby Universe, suggesting that this population merged with other galaxies over several billion years to form the largest galaxies we see today.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/325
- Title:
- Massive galaxy clusters lensing analyse
- Short Name:
- J/MNRAS/404/325
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical analysis of a sample of 20 strong lensing clusters drawn from the Local Cluster Substructure Survey, based on high-resolution Hubble Space Telescope imaging of the cluster cores and follow-up spectroscopic observations using the Keck-I telescope.
- ID:
- ivo://CDS.VizieR/J/MNRAS/383/1513
- Title:
- 2MASS, SDSS and FIRST fluxes of QSOs
- Short Name:
- J/MNRAS/383/1513
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Starting from a sample of Sloan Digital Sky Survey quasars appearing also in the Two-Micron All-Sky Survey, we study the continuum properties of ~1000 objects observed in eight bands, from near-infrared to ultraviolet. We construct the mean spectral energy distribution (SED) and compare and contrast the continua of radio-loud and radio-quiet quasar (RLQ and RQQ, respectively) objects. The SEDs of the two populations are significantly different, in the sense that RLQs are redder with power-law spectral indices <alpha_RLQ_>=0.55+/-0.04 and <alpha_RQQ_>=0.31+/-0.01 in the spectral range between 10^14.5^ and 10^15.35^Hz. This difference is discussed in terms of different extinctions, different disc temperatures, or slopes of the non-thermal component.
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S677
- Title:
- MAXI/GSC catalog in high Galactic-latitude sky
- Short Name:
- J/PASJ/63/S677
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first unbiased source catalog of the Monitor of All-sky X-ray Image (MAXI) mission at high Galactic latitudes (|b|>10{deg}), produced from the first 7-month data (2009 September 1 to 2010 March 31) of the Gas Slit Camera in the 4-10keV band. We have developed an analysis procedure to detect faint sources from the MAXI data, utilizing a maximum likelihood image fitting method, where the image response, background, and detailed observational conditions are taken into account. The catalog consists of 143 X-ray sources above the 7{sigma} significance level with a limiting sensitivity of ~1.5x10^-11^erg/cm^2^/s (1.2mCrab) in the 4-10keV band. Among them, we have identified 38 Galactic/LMC/SMC objects, 48 galaxy clusters, 39 Seyfert galaxies, 12 blazars, and 1 galaxy. Four other sources are confused with multiple objects, and one remains unidentified. The logN-logS relation of extragalactic objects is in good agreement with the HEAO-1 A-2 result, although the list of the brightest AGNs in the entire sky has significantly changed since that produced 30yr ago.
- ID:
- ivo://CDS.VizieR/VII/165A
- Title:
- Measured Redshifts of Abell Clusters of Galaxies
- Short Name:
- VII/165A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 'ACO' catalog (Abell, Corwin and Olowin 1989; Cat. VII/110) that contains 4076 rich (A-) clusters of galaxies and 1174 supplementary (S-) clusters was used to compile this catalog. In the compilation, many papers containing galaxy redshifts were checked for positional coincidences of objects with Abell clusters (typically within one Abell radius). In a total of 1059 ACO clusters a redshift for one or more galaxies were found. These 1059 clusters (records) are sorted by the R.A. (B1950) of their centre. Each record consists of cluster name, cluster centre equatorial coordinates (B1950), Abell richness, distance, Bautz-Morgan class, the magnitude of the tenth-brightest cluster member, cluster measured redshift, the reference code, the Abell radius, and the decimal log of the ratio between measured and estimated redshift.
220. MegaZ-LRG catalogue
- ID:
- ivo://CDS.VizieR/J/MNRAS/375/68
- Title:
- MegaZ-LRG catalogue
- Short Name:
- J/MNRAS/375/68
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the construction of MegaZ-LRG, a photometric redshift catalogue of over one million luminous red galaxies (LRGs) in the redshift range 0.4<z<0.7 with limiting magnitude i<20. The catalogue is selected from the imaging data of the Sloan Digital Sky Survey (SDSS) Data Release 4. The 2dF-SDSS LRG and Quasar (2SLAQ) spectroscopic redshift catalogue of 13000 intermediate-redshift LRGs provides a photometric redshift training set, allowing use of ANNZ, a neural network-based photometric-redshift estimator. The rms photometric redshift accuracy obtained for an evaluation set selected from the 2SLAQ sample is z=0.049 averaged over all galaxies, and z=0.040 for a brighter subsample (i<19.0). The catalogue is expected to contain ~5 per cent stellar contamination. The ANNZ code is used to compute a refined star/galaxy probability based on a range of photometric parameters; this allows the contamination fraction to be reduced to 2 per cent with negligible loss of genuine galaxies. The MegaZ-LRG catalogue is publicly available on the World Wide Web from http://www.2slaq.info .
