- ID:
- ivo://CDS.VizieR/J/ApJ/566/744
- Title:
- EEMSS new X-ray clusters
- Short Name:
- J/ApJ/566/744
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The complete ensemble of Einstein Imaging Proportional Counter (IPC) X-ray images has been reprocessed and reanalyzed using a multiaperture source detection algorithm. A catalog of 772 new source candidates detected within the 38' diameter central regions of the 1435 IPC fields comprising the Extended Medium-Sensitivity Survey (EMSS) has been compiled. By comparison, 478 EMSS sources fall within the same area of sky. A randomly selected subsample of 133 fields was examined; 73 sources were detected and compared with 49 original EMSS sources in the same region of sky.
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Search Results
322. Einstein EMSS Survey
- ID:
- ivo://CDS.VizieR/IX/15
- Title:
- Einstein EMSS Survey
- Short Name:
- IX/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Einstein Extended Medium Sensitivity Survey (EMSS) consists of 835 serendipitous X-ray sources detected at or above 4 times the rms level in 1435 IPC fields with their centers located away from the galactic plane. Their limiting sensitivities range from ~5*10-14 to to ~ 3*10-12 erg.cm-2.s-1 in the 0.3-3.5keV band. A total area of 778 square degrees of the high galactic latitude sky (|b|>20) has been covered. The analysis has been performed using data from the Rev 1 processing system at the CfA. The resulting EMSS catalog is a flux-limited and homogeneous sample of astronomical objects that can be used for statistical studies. Here we present the table listing all the sources taken from the publication referenced below and the optical identifications. At present over 96% of the 835 X-ray sources have been successfully identified in the following proportions: active galactic nuclei (QSO's, quasars and Seyfert), 51.1%; BL Lacertae objects, 4.3%; clusters of galaxies, 12.2%; normal galaxies, 2.1%; cooling flow galaxies, 0.6%; Galactic stars 25.8%; and unidentified, 3.9%. Most of the individual optical counterparts are previously unknown objects and so constitute large statistical samples independent of previously selection methods. The contents of the table is described below. The sky coverage computed for a specific assumed source spectrum is also given under "Additional Information" below. For further details please see the published articles: Gioia et al. 1990, Stocke et al. 1991.
- ID:
- ivo://CDS.VizieR/IX/18
- Title:
- EINSTEIN extended source survey (EXSS)
- Short Name:
- IX/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains sources from data collected by the IPC on board the EINSTEIN Observatory. This survey is designed to find extended sources and diffuse emission rather than point sources. In addition, the source detection algorithm is substantially improved over that used by EMSS. Sources were searched using circular apertures up to 6.1arcmin. The catalog contains 1326 extended source candidates at high galactic latitude (|b| > 20{deg}).
- ID:
- ivo://CDS.VizieR/J/ApJ/511/65
- Title:
- Einstein images of galaxy clusters
- Short Name:
- J/ApJ/511/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the X-ray characteristics of a sample of 368 clusters of galaxies with redshifts less than 0.2 observed with the Einstein Imaging Proportional Counter. For each cluster, we measure the 0.5-4.5keV counting rate and compute the 0.5-4.5keV source luminosity, as well as the bolometric luminosity within fixed metric radii. We detect 85% of Abell clusters with z<0.1, demonstrating that the large majority of these optically selected clusters are not the results of chance superpositions. For 163 clusters, we measure their X-ray surface brightness profiles and determine their core radii. For {~}230 clusters, we then use either our measured core radii and values, or mean values derived for this sample, to measure central gas densities and gas masses. We use estimated or measured cluster gas temperatures, along with the derived gas-density profiles, to estimate total cluster masses, under the assumptions that the gas is isothermal and in hydrostatic equilibrium.
- ID:
- ivo://CDS.VizieR/J/A+A/599/A83
- Title:
- ELG and AGN in WINGS clusters
- Short Name:
- J/A+A/599/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of the emission line galaxies members of 46 low-redshift (0.04<z<0.07) clusters observed by WINGS (WIde-field Nearby Galaxy cluster Survey; Fasano et al., 2006A&A...445..805F). Emission line galaxies were identified following criteria that are meant to minimize biases against non-star-forming galaxies and classified employing diagnostic diagrams. We examined the emission line properties and frequencies of star-forming galaxies, transition objects, and active galactic nuclei (AGNs: LINERs and Seyferts), unclassified galaxies with emission lines, and quiescent galaxies with no detectable line emission. A deficit of emission line galaxies in the cluster environment is indicated by both a lower frequency, and a systematically lower Balmer emission line equivalent width and luminosity with respect to control samples; this implies a lower amount of ionized gas per unit mass and a lower star formation rate if the source is classified as Hii region. A sizable population of transition objects and of low-luminosity LINERs (~10-20% of all emission line galaxies) are detected among WINGS cluster galaxies. These sources are a factor of 1.5 more frequent, or at least as frequent, as in control samples with respect to Hii sources. Transition objects and LINERs in clusters are most affected in terms of line equivalent width by the environment and appear predominantly consistent with so-called retired galaxies. Shock heating can be a possible gas excitation mechanism that is able to account for observed line ratios. Specific to the cluster environment, we suggest interaction between atomic and molecular gas and the intracluster medium as a possible physical cause of line-emitting shocks.
- ID:
- ivo://CDS.VizieR/J/ApJ/693/617
- Title:
- Ellipticities of cluster early-type galaxies
- Short Name:
- J/ApJ/693/617
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled a sample of early-type cluster galaxies from 0<z<1.3 and measured the evolution of their ellipticity distributions. Our sample contains 487 galaxies in 17 z>0.3 clusters with high-quality space-based imaging and a comparable sample of 210 galaxies in 10 clusters at z<0.05. We select early-type galaxies (elliptical and S0 galaxies) that fall within the cluster R_200_, and which lie on the red-sequence in the magnitude range -19.3>M_B_>-21, after correcting for luminosity evolution as measured by the fundamental plane.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A30
- Title:
- Emission-line galaxies in ZwCl0024.0+1652
- Short Name:
- J/A+A/578/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The cores of clusters at 0<~z<~1 are dominated by quiescent early-type galaxies, whereas the field is dominated by star-forming late-type galaxies. Clusters grow through the accretion of galaxies and groups from the surrounding field, which implies that galaxy properties, notably the star formation ability, are altered as they fall into overdense regions. The critical issues for understanding this evolution are how the truncation of star formation is connected to the morphological transformation and what physical mechanism is responsible for these changes. The GaLAxy Cluster Evolution Survey (GLACE) is conducting a thorough study of the variations in galaxy properties (star formation, AGN activity, and morphology) as a function of environment in a representative and well-studied sample of clusters. To address these questions, the GLACE survey is making a deep panoramic survey of emission line galaxies (ELG), mapping a set of optical lines ([OII], [OIII], H{beta} and H{alpha}/[NII] when possible) in several galaxy clusters at z~0.40, 0.63, and 0.86. Using the tunable filters (TF) of the OSIRIS instrument at the 10.4m GTC telescope, the GLACE survey applies the technique of TF tomography: for each line, a set of images are taken through the OSIRIS TF, each image tuned at a different wavelength (equally spaced), to cover a rest frame velocity range of several thousand km/s centred on the mean cluster redshift, and scanned for the full TF field of view of an 8arcmin diameter. Here we present the first results of the GLACE project, targeting the H{alpha}/[NII] lines in the intermediate-redshift cluster ZwCl0024.0+1652 at z=0.395. Two pointings have been performed that cover ~2*r_vir_.
- ID:
- ivo://CDS.VizieR/J/A+A/446/19
- Title:
- ENACS. VIII. Galaxies classification
- Short Name:
- J/A+A/446/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We determine the morphological types of 2295 galaxies from the ESO Nearby Abell Cluster Survey (ENACS) from CCD images obtained with the Dutch telescope on La Silla. A comparison with morphological types from the literature for 450 of our galaxies shows that the reliability of our classification is quite comparable to that of other classifiers. We recalibrate the ENACS spectral classification with the new morphological types, and find that early- and late-type galaxies can be distinguished from their spectra with 83% reliability. Ellipticals and S0 galaxies can hardly be distinguished on the basis of their spectra, but late spirals can be classified from the spectrum alone with more than 70% reliability.
- ID:
- ivo://CDS.VizieR/J/ApJ/889/185
- Title:
- Environment in galaxy evolution in SERVS. I.
- Short Name:
- J/ApJ/889/185
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use photometric redshifts derived from new u-band through 4.5{mu}m Spitzer IRAC photometry in the 4.8deg^2^ of the XMM-LSS field to construct surface density maps in the redshift range of 0.1-1.5. Our density maps show evidence for large-scale structure in the form of filaments spanning several tens of megaparsecs. Using these maps, we identify 339 overdensities that our simulated light-cone analysis suggests are likely associated with dark matter halos with masses, M_halo_, log(M_halo_/M_{sun}_)>13.7. From this list of overdensities we recover 43 of 70 known X-ray-detected and spectroscopically confirmed clusters. The missing X-ray clusters are largely at lower redshifts and lower masses than our target log(M_halo_/M_{sun}_)>13.7. The bulk of the overdensities are compact, but a quarter show extended morphologies that include likely projection effects, clusters embedded in apparent filaments, and at least one potential cluster merger (at z~1.28). The strongest overdensity in our highest-redshift slice (at z~1.5) shows a compact red galaxy core, potentially implying a massive evolved cluster.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A32
- Title:
- Equivalent widths of WINGS galaxies
- Short Name:
- J/A+A/566/A32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of Equivalent Width (EW) measurements of spectra from the spectroscopic follow-up of the WIde-field Nearby Galaxy-cluster Survey (WINGS).Using the Anglo Australian Telescope (AAT) and the William Herschel Telescope (WHT), we have obtained optical spectra for about 6000 galaxies selected in fields centered on 48 local (0.04<z<0.07) X-ray selected. We apply a method we have developed to automatically measure the EW of spectral lines in a robust way even in spectra with a non optimal signal to noise. This way, we derive a spectral classification reflecting the stellar content, based on the presence and strength of the [OII] (3727) and H{delta} lines.
