- ID:
- ivo://CDS.VizieR/J/ApJ/819/63
- Title:
- Hectospec survey of SZ clusters (HeCS-SZ)
- Short Name:
- J/ApJ/819/63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We estimate cluster masses and velocity dispersions for 123 clusters from optical spectroscopy to compare the Sunyaev-Zeldovich (SZ) mass proxy and dynamical masses. Our new survey, HeCS-SZ (Hectospec Cluster Survey of SZ-selected clusters), includes 7721 new or remeasured redshifts from MMT/Hectospec observations of 21 SZ-selected clusters at redshifts z=0.05-0.20. We supplement the Hectospec data with spectra from the Sloan Digital Sky Survey (SDSS) and cluster data from the Cluster Infall Regions in SDSS project and the Hectospec Cluster Survey, our Hectospec survey of clusters selected by X-ray flux. We measure the scaling relation between velocity dispersion and SZ mass estimates from the integrated Compton parameter for an SZ-complete sample of 83 clusters. The observed relation agrees very well with a simple virial scaling from mass (based on SZ) to velocity dispersion. The SZ mass estimates (calibrated with hydrostatic X-ray mass estimates) are not significantly biased compared to dynamical mass estimates under the assumption of small velocity bias of galaxies compared to dark matter particles. Significant mass bias in SZ mass estimates could relieve tension between cosmological results from Planck SZ cluster counts and Planck CMB data. In principle, SZ mass bias and velocity bias of galaxies could conspire to yield good agreement, but the required velocity bias is {sigma}_galaxy_~0.77{sigma}_DM_, outside the range of recent models of velocity bias in the literature. More likely, SZ mass bias and velocity bias are both small, and the tension between SZ cluster counts and CMB data requires another explanation.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/513/A15
- Title:
- Heidelberg InfraRed Optical Cluster Survey, HIROCS
- Short Name:
- J/A+A/513/A15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a survey for distant clusters of galaxies that identified clusters as local overdensities in the 3D galaxy distribution. Optical and near-IR imaging in B, R, i, z, and H are used to derive photometric redshifts for objects as faint as m*+1 at a redshift of 1.5. We outline the astrometric and photometric data reduction. The 3D cluster search, based on the photometric redshifts, is described.
- ID:
- ivo://CDS.VizieR/J/A+A/407/31
- Title:
- Heliocentric radial velocities in Abell 376
- Short Name:
- J/A+A/407/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a dynamical analysis of the galaxy cluster Abell 376 based on a set of 73 velocities, most of them measured at Pic du Midi and Haute-Provence observatories and completed with data from the literature. Data on individual galaxies are presented and the accuracy of the determined velocities is discussed as well as some properties of the cluster. We obtained an improved mean redshift value z=0.0478^+0.005_-0.006_ and velocity dispersion {sigma}=852^+120^_-76_km/s. Our analysis indicates that inside a radius of ~900h_70_^-1^kpc (~15-arcmin) the cluster is well relaxed without any remarkable feature and the X-ray emission traces fairly well the galaxy distribution. A possible substructure is seen at 20-arcmin from the centre towards the Southwest direction, but is not confirmed by the velocity field. This SW clump is, however, kinematically bound to the main structure of Abell 376. A dense condensation of galaxies is detected at 46 arcmin (projected distance 2.6h_70_^-1^Mpc) from the centre towards the Northwest and analysis of the apparent luminosity distribution of its galaxies suggests that this clump is part of the large scale structure of Abell 376. X-ray spectroscopic analysis of ASCA data resulted in a temperature kT=4.3+/-0.4keV and metal abundance Z=0.32+/-0.08Z_{sun}. The velocity dispersion corresponding to this temperature using the T_X_-{sigma} scaling relation is in agreement with the measured galaxies velocities.
- ID:
- ivo://CDS.VizieR/J/AJ/115/6
- Title:
- Hercules supercluster kinematics
- Short Name:
- J/AJ/115/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Hercules supercluster consists of the Abell clusters A2147, A2151, and A2152. Previous studies of the kinematics have been confounded by the difficulty of correctly assigning galaxies to the individual clusters, which are not well separated. Our study has a total of 468 available velocities for galaxies in the region, 175 of them new. There are 414 galaxies in the supercluster, about 3 times the number used in the previous supercluster study. We verify the existence of the three individual clusters and compute their individual dynamical parameters. We investigate several techniques for assigning galaxy membership to clusters in this crowded field. We use the Kaye's mixture model (Ashman, Bird, & Zepf, 1994AJ....108.2348A) algorithm to separate the galaxies into clusters; we find that A2152 has a higher mean velocity than previous studies have reported. A2147 and A2152 also have lower velocity dispersions: 821^+68^_-55_ and 715^+81^_-61_km/s, respectively. The assignment of galaxies to either A2152 or A2147 requires velocity and position information. We study the kinematics of the supercluster using the two-body formalism of Beers, Geller, & Huchra (1982ApJ...257...23B) and conclude that A2147 and A2151 are probably bound to each other and that the supercluster as a whole may also be bound. The mass of the supercluster, if bound, is (7.6+/-2.0)x10^15^h^-1^M_{sun}_; with the supercluster luminosity, (1.4+/-0.2)x10^13^h^-2^L_{sun}_, this yields {OMEGA}=0.34+/-0.1.
- ID:
- ivo://CDS.VizieR/J/MNRAS/440/1571
- Title:
- Herschel fluxes of Fornax galaxies
- Short Name:
- J/MNRAS/440/1571
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Herschel Fornax Cluster Survey is a deep, far-infrared (FIR) survey of the Fornax cluster. The survey is in five Herschel bands (100-500{mu}m) and covers an area of 16deg^2^ centred on NGC 1399. This paper presents photometry, detection rates, dust masses, and temperatures using an optically selected sample from the Fornax Cluster Catalogue. Our results are compared with those previously obtained using data from the Herschel Virgo Cluster Survey (HeViCS). In Fornax, we detect 30 of the 237 (13%) optically selected galaxies in at least one Herschel band. The global detection rates are significantly lower than Virgo, reflecting the morphological make up of each cluster - Fornax has a lower fraction of late-type galaxies. For galaxies detected in at least three bands, we fitted a modified blackbody with a {beta}=2 emissivity. Detected early-type galaxies (E/S0) have a mean dust mass, temperature, and dust-to-stars ratio of log10(<M_dust_>/M_{sun}_)=5.82+/-0.20, <T_dust_>=20.82+/-1.77K, and log_10_(M_dust_/M_stars_)=-3.87+/-0.28, respectively. Late-type galaxies (Sa to Sd) have a mean dust mass, temperature, and dust-to-stars ratio of log10(M_dust_>/M_{sun}_)=6.54+/-0.19, <T_dust_>=17.47+/-0.97K, and log_10_(M_dust_/M_stars_)=-2.93+/-0.09, respectively. The different cluster environments seem to have had little effect on the FIR properties of the galaxies and so we conclude that any environment-dependent evolution has taken place before the cluster was assembled.
- ID:
- ivo://CDS.VizieR/J/MNRAS/460/3861
- Title:
- Herschel protocluster survey
- Short Name:
- J/MNRAS/460/3861
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Herschel/Spectral and Photometric Imaging Receiver (SPIRE) survey of three protoclusters at z=2-3 (2QZCluster, HS1700, SSA22). Based on the SPIRE colours (S_350_/S_250_ and S_500_/S_350_) of 250{mu}m sources, we selected high-redshift dusty star-forming galaxies potentially associated with the protoclusters. In the 2QZCluster field, we found a 4{sigma} overdensity of six SPIRE sources around 4.5-arcmin (~2.2Mpc) from a density peak of H {alpha} emitters at z=2.2. In the HS1700 field, we found a 5{sigma} overdensity of eight SPIRE sources around 2.1-arcmin (~1.0Mpc) from a density peak of Lyman-break galaxies at z=2.3. We did not find any significant overdensities in SSA22 field, but we found three 500 {mu}m sources are concentrated 3-arcmin (~1.4Mpc) east to the Ly {alpha} emitters overdensity. If all the SPIRE sources in these three overdensities are associated with protoclusters, the inferred star formation rate densities are 10^3^-10^4^ times higher than the average value at the same redshifts. This suggests that dusty star formation activity could be very strongly enhanced in z~2-3 protoclusters. Further observations are needed to confirm the redshifts of the SPIRE sources and to investigate what processes enhance the dusty star formation activity in z~2-3 protoclusters.
- ID:
- ivo://CDS.VizieR/J/A+A/574/A126
- Title:
- HeViCS. XVIII. Star-forming dwarf galaxies
- Short Name:
- J/A+A/574/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To assess the effects of the cluster environment on the different components of the interstellar medium, we analyse the far-infrared (FIR) and submillimetre (submm) properties of a sample of star-forming dwarf galaxies detected by the Herschel Virgo Cluster Survey (HeViCS). We determine dust masses and dust temperatures by fitting a modified black body function to the spectral energy distributions (SEDs). Stellar and gas masses, star formation rates (SFRs), and metallicities are obtained from the analysis of a set of ancillary data. Dust is detected in 49 out of a total 140 optically identified dwarfs covered by the HeViCS field; considering only dwarfs brighter than m_B_=18mag, this gives a detection rate of 43%. After evaluating different emissivity indices, we find that the FIR-submm SEDs are best-fit by {beta}=1.5, with a median dust temperature T_d_=22.4K. Assuming {beta}=1.5, 67% of the 23 galaxies detected in all five Herschel bands show emission at 500{mu}m in excess of the modified black-body model. The fraction of galaxies with a submillimetre excess decreases for lower values of {beta}, while a similarly high fraction (54%) is found if a {beta}-free SED modelling is applied. The excess is inversely correlated with SFR and stellar masses. To study the variations in the global properties of our sample that come from environmental effects, we compare the Virgo dwarfs to other Herschel surveys, such as the Key Insights into Nearby Galaxies: Far-Infrared Survey with Herschel (KINGFISH), the Dwarf Galaxy Survey (DGS), and the HeViCS Bright Galaxy Catalogue (BGC). We explore the relations between stellar mass and HI fraction, specific star formation rate, dust fraction, gas-to-dust ratio over a wide range of stellar masses (from 10^7^ to 10^11^M_{sun}_) for both dwarfs and spirals. Highly HI-deficient Virgo dwarf galaxies are mostly characterised by quenched star formation activity and lower dust fractions giving hints for dust stripping in cluster dwarfs. However, to explain the large dust-to-gas mass ratios observed in these systems, we find that the fraction of dust removed has to be less than that of the HI component. The cluster environment seems to mostly affect the gas component and star formation activity of the dwarfs. Since the Virgo star-forming dwarfs are likely to be crossing the cluster for the first time, a longer timescale might be necessary to strip the more centrally concentrated dust distribution.
- ID:
- ivo://CDS.VizieR/J/A+A/597/A130
- Title:
- HI and 250um images of the Virgo cirrus
- Short Name:
- J/A+A/597/A130
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the correlation between far-infrared/submm dust emission and atomic gas column density in order to derive the properties of the high Galactic latitude, low density, Milky Way cirrus in the foreground of the Virgo cluster of galaxies. Dust emission maps from 60 to 850um are obtained from SPIRE observations carried out within the Herschel Virgo Cluster Survey, complemented by IRAS-IRIS and Planck-HFI maps. Data from the Arecibo legacy Fast ALFA Survey is used to derive atomic gas column densities for two broad velocity components, low and intermediate velocity clouds. Dust emissivities are derived for each gas component and each far-infrared/submm band. For the low velocity clouds, we measure an average emissivity {epsilon]_{nu}^LVC=(0.79+/-0.08)*10^-20^MJy.cm^2^/sr at 250um. After fitting a modified blackbody to the available bands, we estimated a dust absorption cross-section {tau}_{nu}^LVC/N_HI_=(0.49+/-0.13)*10^-25cm^2^/H at 250um (with dust temperature T=20.4+/-1.5K and spectral index {beta}=1.53+/-0.17). The results are in excellent agreement with those obtained by Planck over a much larger coverage of the high Galactic latitude cirrus (50% of the sky vs 0.2% in our work). For dust associated with intermediate velocity gas, we confirm earlier Planck results and find a higher temperature and lower emissivity and cross-section. After subtracting the modelled components, we find regions at scales smaller than 20' where the residuals deviate significantly from the average, cosmic-infrared-background dominated, scatter. These large residuals are most likely due to local variations in the cirrus dust properties (and/or the dust/atomic-gas correlation) or to high-latitude molecular clouds with average N_H2_<~10^20^cm^-2^. We find no conclusive evidence for intracluster dust emission in Virgo.
- ID:
- ivo://CDS.VizieR/J/A+A/565/A25
- Title:
- Hickson compact groups Herschel observations
- Short Name:
- J/A+A/565/A25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Herschel far-infrared and sub-millimetre (sub-mm) study of a sample of 120 galaxies in 28 Hickson compact groups (HCGs). Fitting their UV to sub-mm spectral energy distributions with the model of da Cunha et al. (2008MNRAS.388.1595C), we accurately estimate the dust masses, luminosities, and temperatures of the individual galaxies.
- ID:
- ivo://CDS.VizieR/VII/85A
- Title:
- Hickson Compact Groups of Galaxies
- Short Name:
- VII/85A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a list of 100 compact groups of galaxies identified by a systematic search of the Palomar Observatory Sky Survey red prints. Each group contains four or more galaxies, has an estimated mean surface brightness brighter than 26.0 magnitude per arcsec and satisfies an isolation criterion. The catalog includes running numbers, equatorial coordinates, group types according to the two brightest members, number of galaxies in the group, angular diameters of the smallest circles containing the geometric centers of all group members, total magnitudes (red) of those galaxies counted as group members, estimated red magnitudes of the brightest galaxies in the groups, corrected redshifts of the brightest galaxies, and other designations of the groups.
