Imaging the Thermal and Kinematic Sunyaev-Zel'dovich Effect Signals in a Sample of Ten Massive Galaxy Clusters: Constraints on Internal Velocity Structures and Bulk Velocities

We have imaged the Sunyaev-Zel'dovich (SZ) effect signals at 140 and 270 GHz towards ten galaxy clusters with Bolocam and AzTEC/ASTE. We also used Planck data to constrain the signal at large angular scales, Herschel-SPIRE images to subtract the brightest galaxies that comprise the cosmic infrared background (CIB), Chandra imaging to map the electron temperature $T_e$ of the intra-cluster medium (ICM), and HST imaging to derive models of each galaxy cluster's mass density. The galaxy clusters gravitationally lens the background CIB, which produced an on-average reduction in brightness towards the galaxy clusters' centers after the brightest galaxies were subtracted. We corrected for this deficit, which was between 5-25% of the 270 GHz SZ effect signal within $R_{2500}$. Using the SZ effect measurements, along with the X-ray constraint on $T_e$, we measured each galaxy cluster's average line of sight (LOS) velocity $v_z$ within $R_{2500}$, with a median per-cluster uncertainty of +-700 km/s. We found an ensemble-mean of 430+-210 km/s, and an intrinsic cluster-to-cluster scatter $\sigma_{int}$ of 470+-340 km/s. We also obtained maps of $v_z$ over each galaxy cluster's face with an angular resolution of 70". All four galaxy clusters previously identified as having a merger oriented along the LOS showed an excess variance in these maps at a significance of 2-4$\sigma$, indicating an internal $v_z$ rms of $\gtrsim$1000 km/s. None of the six galaxy clusters previously identified as relaxed or plane of sky mergers showed any such excess variance.Comment: Accepted for publication in Ap

Imaging the Thermal and Kinematic Sunyaev–Zel’dovich Effect Signals in a Sample of 10 Massive Galaxy Clusters: Constraints on Internal Velocity Structures and Bulk Velocities

We have imaged the Sunyaev–Zel'dovich (SZ) effect signals at 140 and 270 GHz toward 10 galaxy clusters with Bolocam and AzTEC/ASTE. We also used Planck data to constrain the signal at large angular scales, Herschel–SPIRE images to subtract the brightest galaxies that comprise the cosmic infrared background (CIB), Chandra imaging to map the electron temperature T_e of the intra-cluster medium, and Hubble Space Telescope imaging to derive models of each galaxy cluster's mass density. The galaxy clusters gravitationally lens the background CIB, which produced an on-average reduction in brightness toward the galaxy clusters' centers after the brightest galaxies were subtracted. We corrected for this deficit, which was between 5% and 25% of the 270 GHz SZ effect signal within R_(2500). Using the SZ effect measurements, along with the X-ray constraint on T_e , we measured each galaxy cluster's average line of sight (LOS) velocity v_z within R_(2500), with a median per-cluster uncertainty of ±700 km s^(−1). We found an ensemble-mean〈v_z 〉of 430 ± 210 km s^(−1), and an intrinsic cluster-to-cluster scatter σ_(int) of 470 ± 340 km s−1. We also obtained maps of v_z over each galaxy cluster's face with an angular resolution of 70''. All four galaxy clusters previously identified as having a merger oriented along the LOS showed an excess variance in these maps at a significance of ≃2–4σ, indicating an internal v_z rms of ≳1000 km s^(−1). None of the six galaxy clusters previously identified as relaxed or plane-of-sky mergers showed any such excess variance

RELICS: High-Resolution Constraints on the Inner Mass Distribution of the z=0.83 Merging Cluster RXJ0152.7-1357 from strong lensing

Strong gravitational lensing (SL) is a powerful means to map the distribution of dark matter. In this work, we perform a SL analysis of the prominent X-ray cluster RXJ0152.7-1357 (z=0.83, also known as CL 0152.7-1357) in \textit{Hubble Space Telescope} images, taken in the framework of the Reionization Lensing Cluster Survey (RELICS). On top of a previously known $z=3.93$ galaxy multiply imaged by RXJ0152.7-1357, for which we identify an additional multiple image, guided by a light-traces-mass approach we identify seven new sets of multiply imaged background sources lensed by this cluster, spanning the redshift range [1.79-3.93]. A total of 25 multiple images are seen over a small area of ~0.4 $arcmin^2$, allowing us to put relatively high-resolution constraints on the inner matter distribution. Although modestly massive, the high degree of substructure together with its very elongated shape make RXJ0152.7-1357 a very efficient lens for its size. This cluster also comprises the third-largest sample of z~6-7 candidates in the RELICS survey. Finally, we present a comparison of our resulting mass distribution and magnification estimates with those from a Lenstool model. These models are made publicly available through the MAST archive.Comment: 15 Pages, 7 Figures, 4 Tables Accepted for publication in Ap

A Candidate z∼10z\sim10 Galaxy Strongly Lensed into a Spatially Resolved Arc

The most distant galaxies known are at z~10-11, observed 400-500 Myr after the Big Bang. The few z~10-11 candidates discovered to date have been exceptionally small- barely resolved, if at all, by the Hubble Space Telescope. Here we present the discovery of SPT0615-JD, a fortuitous z~10 (z_phot=9.9+/-0.6) galaxy candidate stretched into an arc over ~2.5" by the effects of strong gravitational lensing. Discovered in the Reionization Lensing Cluster Survey (RELICS) Hubble Treasury program and companion S-RELICS Spitzer program, this candidate has a lensed H-band magnitude of 25.7+/-0.1 AB mag. With a magnification of \mu~4-7 estimated from our lens models, the de-lensed intrinsic magnitude is 27.6+/-0.3 AB mag, and the half-light radius is r_e<0.8 kpc, both consistent with other z>9 candidates. The inferred stellar mass (log [M* /M_Sun]=9.7^{+0.7}_{-0.5}) and star formation rate (\log [SFR/M_Sun yr^{-1}]=1.3^{+0.2}_{-0.3}) indicate that this candidate is a typical star-forming galaxy on the z>6 SFR-M* relation. We note that three independent lens models predict two counterimages, at least one of which should be of a similar magnitude to the arc, but these counterimages are not yet detected. Counterimages would not be expected if the arc were at lower redshift. However, the only spectral energy distributions capable of fitting the Hubble and Spitzer photometry well at lower redshifts require unphysical combinations of z~2 galaxy properties. The unprecedented lensed size of this z~10 candidate offers the potential for the James Webb Space Telescope to study the geometric and kinematic properties of a galaxy observed 500 Myr after the Big Bang.Comment: 7 pages, 4 figures. Submitted to ApJ Letter

RELICS: Strong Lensing analysis of the galaxy clusters Abell S295, Abell 697, MACS J0025.4-1222, and MACS J0159.8-0849

We present a strong-lensing analysis of four massive galaxy clusters imaged with the Hubble Space Telescope in the Reionization Lensing Cluster Survey. We use a Light-Traces-Mass technique to uncover sets of multiply images and constrain the mass distribution of the clusters. These mass models are the first published for Abell S295 and MACS J0159.8-0849, and are improvements over previous models for Abell 697 and MACS J0025.4-1222. Our analysis for MACS J0025.4-1222 and Abell S295 shows a bimodal mass distribution supporting the merger scenarios proposed for these clusters. The updated model for MACS J0025.4-1222 suggests a substantially smaller critical area than previously estimated. For MACS J0159.8-0849 and Abell 697 we find a single peak and relatively regular morphology, revealing fairly relaxed clusters. Despite being less prominent lenses, three of these clusters seem to have lensing strengths, i.e. cumulative area above certain magnification, similar to the Hubble Frontier Fields clusters (e.g., A($\mu>5$) $\sim 1-3$ arcmin$^2$, A($\mu>10$) $\sim 0.5-1.5$ arcmin$^2$), which in part can be attributed to their merging configurations. We make our lens models publicly available through the Mikulski Archive for Space Telescopes. Finally, using Gemini-N/GMOS spectroscopic observations we detect a single emission line from a high-redshift $J_{125}\simeq25.7$ galaxy candidate lensed by Abell 697. While we cannot rule out a lower-redshift solution, we interpret the line as Ly$\alpha$ at $z=5.800\pm 0.001$, in agreement with its photometric redshift and dropout nature. Within this scenario we measure a Ly$\alpha$ rest-frame equivalent width of $52\pm22$ \AA, and an observed Gaussian width of $117\pm 15$ km/s.Comment: 23 pages, 16 figures; V2, accepted for publication in Ap

The SOAR Gravitational ARC Survey

We present the first results of the SOAR Gravitational\ud Arc Survey (SOGRAS). The survey imaged 47\ud clusters in two redshift intervals centered at z = 0.27\ud and z = 0.55, targeting the richest clusters in each\ud interval. Images were obtained in the g′, r′ and i′\ud bands with a median seeing of 0.83, 0.76 and 0.71\ud arcsec, respectively, in these filters. Most of the survey\ud clusters are located within the Sloan Digital Sky\ud Survey (SDSS) Stripe-82 region and all of them are\ud in the SDSS footprint. We present the first results\ud of the survey, including the 6 best strong lensing\ud systems, photometric and morphometric catalogs of\ud the galaxy sample, and cross matches of the clusters\ud and galaxies with complementary samples (spectroscopic\ud redshifts, photometry in several bands, X-ray\ud and Sunyaev Zel’dovich clusters, etc.), exploiting the\ud synergy with other surveys in Stripe-82. We apply\ud several methods to characterize the gravitational arc\ud candidates, including the Mediatrix method (Bom\ud et al. 2012) and ArcFitting (Furlanetto et al. 2012),\ud and for the subtraction of galaxy cluster light. Finally,\ud we apply strong lensing inversion techniques to\ud the best systems, providing constraints on their mass\ud distribution. The analyses of a spectral follow-up with Gemini and the derived dynamical masses are\ud presented in a poster submitted to this same meeting\ud (Cibirka et al.).\ud Deeper follow-up images with Gemini strengthen\ud the case for the strong lensing nature of the candidates\ud found in this survey.Resumo publicado no periódico: Revista Mexicana de Astronomía y Astrofísica. Serie de Conferencias, v. 44, p. 180-181, 2014

RELICS: Strong-lensing Analysis of the Massive Clusters MACS J0308.9+2645 and PLCK G171.9−40.7

Strong gravitational lensing by galaxy clusters has become a powerful tool for probing the high-redshift universe, magnifying distant and faint background galaxies. Reliable strong-lensing (SL) models are crucial for determining the intrinsic properties of distant, magnified sources and for constructing their luminosity function. We present here the first SL analysis of MACS J0308.9+2645 and PLCK G171.9-40.7, two massive galaxy clusters imaged with the Hubble Space Telescope, in the framework of the Reionization Lensing Cluster Survey (RELICS). We use the light-traces-mass modeling technique to uncover sets of multiply imaged galaxies and constrain the mass distribution of the clusters. Our SL analysis reveals that both clusters have particularly large Einstein radii (theta(E) > 30 '' for a source redshift of z(s) = 2), providing fairly large areas with high magnifications, useful for high-redshift galaxy searches (similar to 2 arcmin(2) with mu > 5 to similar to 1 arcmin(2) with mu > 10, similar to a typical Hubble Frontier Fields cluster). We also find that MACS J0308.9+2645 hosts a promising, apparently bright (J similar to 23.2-24.6 AB), multiply imaged high-redshift candidate at z similar to 6.4. These images are among the brightest high-redshift candidates found in RELICS. Our mass models, including magnification maps, are made publicly available for the community through the Mikulski Archive for Space Telescopes.NASA/ESA HST [GO-14096]; NASA through a Space Telescope Science Institute [GO-14096]; NASA [NAS5-26555]; U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]; Australian Research Council Discovery Early Career Researcher Award [DE180101240]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

RELICS: Strong Lensing Analysis of MACS J0417.5–1154 and Predictions for Observing the Magnified High-redshift Universe with JWST

Strong gravitational lensing by clusters of galaxies probes the mass distribution at the core of each cluster and magnifies the universe behind it. MACS J0417.5−1154 at z = 0.443 is one of the most massive clusters known based on weak lensing, X-ray, and Sunyaev–Zel'dovich analyses. Here we compute a strong lens model of MACS J0417 based on Hubble Space Telescope imaging observations collected, in part, by the Reionization Lensing Cluster Survey (RELICS), and recently reported spectroscopic redshifts from the MUSE instrument on the Very Large Telescope (VLT). We measure an Einstein radius of ${\theta }_{E}\simeq 36^{\prime\prime}$ at z = 9 and a mass projected within 200 kpc of ${M}_{(200\mathrm{kpc})}={1.78}_{-0.03}^{+0.01}\times {10}^{14}$ M ${}_{\odot }$. Using this model, we measure a ratio between the mass attributed to cluster-member galaxy halos and the main cluster halo of order 1:100. We assess the probability to detect magnified high-redshift galaxies in the field of this cluster, both for comparison with RELICS HST results and as a prediction for the James Webb Space Telescope (JWST) Guaranteed Time Observations upcoming for this cluster. Our lensing analysis indicates that this cluster has similar lensing strength to other clusters in the RELICS program. Our lensing analysis predicts a detection of at least a few z ~ 6–8 galaxies behind this cluster, at odds with a recent analysis that yielded no such candidates in this field. Reliable strong lensing models are crucial for accurately predicting the intrinsic properties of lensed galaxies. As part of the RELICS program, our strong lensing model produced with the Lenstool parametric method is publicly available through the Mikulski Archive for Space Telescopes