Browsing by Author "Forman, W. R."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    COSMOLOGICAL CONSTRAINTS FROM SUNYAEV-ZEL'DOVICH-SELECTED CLUSTERS WITH X-RAY OBSERVATIONS IN THE FIRST 178 deg2 OF THE SOUTH POLE TELESCOPE SURVEY
    (2013) Benson, B. A.; de Haan, T.; Dudley, J. P.; Reichardt, C. L.; Aird, K. A.; Andersson, K.; Armstrong, R.; Ashby, M. L. N.; Bautz, M.; Bayliss, M.; Bazin, G.; Bleem, L. E.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; Desai, S.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Harrington, N.; High, F. W.; Holder, G. P.; Holzapfel, W. L.; Hoover, S.; Hrubes, J. D.; Jones, C.; Joy, M.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McDonald, M.; McMahon, J. J.; Mehl, J.; Meyer, S. S.; Mocanu, L.; Mohr, J. J.; Montroy, T. E.; Murray, S. S.; Natoli, T.; Padin, S.; Plagge, T.; Pryke, C.; Rest, A.; Ruel, J.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shaw, L.; Shirokoff, E.; Song, J.; Spieler, H. G.; Stalder, B.; Staniszewski, Z.; Stark, A. A.; Story, K.; Stubbs, C. W.; Suhada, R.; van Engelen, A.; Vanderlinde, K.; Vieira, J. D.; Vikhlinin, A.; Williamson, R.; Zahn, O.; Zenteno, A.
    We usemeasurements from the South Pole Telescope (SPT) Sunyaev-Zel'dovich (SZ) cluster survey in combination with X-ray measurements to constrain cosmological parameters. We present a statistical method that fits for the scaling relations of the SZ and X-ray cluster observables with mass while jointly fitting for cosmology. The method is generalizable to multiple cluster observables, and self-consistently accounts for the effects of the cluster selection and uncertainties in cluster mass calibration on the derived cosmological constraints. We apply this method to a data set consisting of an SZ-selected catalog of 18 galaxy clusters at z > 0.3 from the first 178 deg(2) of the 2500 deg(2) SPT-SZ survey, with 14 clusters having X-ray observations from either Chandra or XMM-Newton. Assuming a spatially flat Lambda CDM cosmological model, we find the SPT cluster sample constrains sigma(8)(Omega(m)/0.25)(0.30) = 0.785 +/- 0.037. In combination with measurements of the cosmic microwave background (CMB) power spectrum from the SPT and the seven-year Wilkinson Microwave Anisotropy Probe data, the SPT cluster sample constrains sigma(8) = 0.795 +/- 0.016 and Omega(m) = 0.255 +/- 0.016, a factor of 1.5 improvement on each parameter over the CMB data alone. We consider several extensions beyond the Lambda CDM model by including the following as free parameters: the dark energy equation of state (w), the sum of the neutrino masses (Sigma m(nu)), the effective number of relativistic species (N-eff), and a primordial non-Gaussianity (f(NL)). We find that adding the SPT cluster data significantly improves the constraints on w and Sigma m(nu) beyond those found when using measurements of the CMB, supernovae, baryon acoustic oscillations, and the Hubble constant. Considering each extension independently, we best constrain w = -0.973 +/- 0.063 and the sum of neutrino masses Sigma m(nu) < 0.28 eV at 95% confidence, a factor of 1.25 and 1.4 improvement, respectively, over the constraints without clusters. Assuming a Lambda CDM model with a free N-eff and Sigma m(nu), we measure N-eff = 3.91 +/- 0.42 and constrain Sigma m(nu) < 0.63 eV at 95% confidence. We also use the SPT cluster sample to constrain f(NL) = -220 +/- 317, consistent with zero primordial non-Gaussianity. Finally, we discuss the current systematic limitations due to the cluster mass calibration, and future improvements for the recently completed 2500 deg(2) SPT-SZ survey. The survey has detected similar to 500 clusters with a median redshift of similar to 0.5 and a median mass of similar to 2.3 x 10(14) M-circle dot h(-1) and, when combined with an improved cluster mass calibration and existing external cosmological data sets will significantly improve constraints on w.
  • No Thumbnail Available
    Item
    Extended X-Ray Emission around FR II Radio Galaxies: Hot Spots, Lobes, and Galaxy Clusters
    (2021) Jimenez-Gallardo, A.; Massaro, F.; Paggi, A.; D'Abrusco, R.; Prieto, M. A.; Pena-Herazo, H. A.; Berta, V; Ricci, F.; Stuardi, C.; Wilkes, B. J.; O'Dea, C. P.; Baum, S. A.; Kraft, R. P.; Forman, W. R.; Jones, C.; Mingo, B.; Liuzzo, E.; Balmaverde, B.; Capetti, A.; Missaglia, V; Hardcastle, M. J.; Baldi, R. D.; Morabito, L. K.
    We present a systematic analysis of the extended X-ray emission discovered around 35 FR II radio galaxies from the revised Third Cambridge Catalog (3CR) Chandra Snapshot Survey with redshifts between 0.05 and 0.9. We aimed to (i) test for the presence of extended X-ray emission around FR II radio galaxies, (ii) investigate whether the extended emission origin is due to inverse Compton (IC) scattering of seed photons arising from the cosmic microwave background (CMB) or thermal emission from an intracluster medium (ICM), and (iii) test the impact of this extended emission on hot-spot detection. We investigated the nature of the extended X-ray emission by studying its morphology and compared our results with low-frequency radio observations (i.e., similar to 150 MHz) in the TGSS and LOFAR archives, as well as with optical images from Pan-STARRS. In addition, we optimized a search for X-ray counterparts of hot spots in 3CR FR II radio galaxies. We found statistically significant extended emission (>3 sigma confidence level) along the radio axis of similar to 90% and in the perpendicular direction of similar to 60% of the galaxies in our sample. We confirmed the detection of seven hot spots in the 0.5-3 keV energy range. In the cases where the emission in the direction perpendicular to the radio axis is comparable to that along the radio axis, we suggest that the underlying radiative process is thermal emission from the ICM. Otherwise, the dominant radiative process is likely nonthermal IC/CMB emission from lobes. We found that nonthermal IC/CMB is the dominant process in similar to 70% of the sources in our sample, while thermal emission from the ICM dominates in similar to 15% of them.