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The fundamental plane for z = 0.8-0.9 cluster galaxies

Astrophysical Journal 639:1 II (2006) L9-L12

Authors:

I Jørgensen, K Chiboucas, K Flint, M Bergmann, J Barr, R Davies

Abstract:

We present the fundamental plane (FP) for 38 early-type galaxies in the two rich galaxy clusters RX J0152.7-1357 (z = 0.83) and RX J1226.9+3332 (z = 0.89), reaching a limiting magnitude of MB = -19.8 in the rest frame of the clusters. While the zero-point offset of the FP for these high-redshift clusters relative to our low-redshift sample is consistent with passive evolution with a formation redshift of zform ≈ 3.2, the FP for the high-redshift clusters is not only shifted as expected for a mass-independent zform but rotated relative to the low-redshift sample. Expressed as a relation between the galaxy masses and the mass-to-light ratios, the FP is significantly steeper for the high-redshift clusters than for our low-redshift sample. We interpret this as a mass dependency of the star formation history, as has been suggested by other recent studies. The low-mass galaxies (10 10.3 M⊙) have experienced star formation as recently as z ≈ 1.35 (1.5 Gyr prior to their look-back time), while galaxies with masses larger than 1011.3 M⊙ had their last major star formation episode at z > 4.5. © 2006, The American Astronomical Society. All rights reserved.
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The SAURON project - IV. The mass-to-light ratio, the virial mass estimator and the Fundamental Plane of elliptical and lenticular galaxies

Monthly Notices of the Royal Astronomical Society 366 (2006) 1126-1150

Authors:

M Cappellari, Bacon, R., Bureau, M., Damen, M. C.
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The central kinematics of NGC 1399 measured with 14 pc resolution

Monthly Notices of the Royal Astronomical Society 367 (2006) 2-18

Authors:

SJ Magorrian, R.C.W. Houghton, M. Sarzi, N. Thatte
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Radiative decays of the Υ(1S) to a pair of charged hadrons

Physical Review D - Particles, Fields, Gravitation and Cosmology 73:3 (2006)

Authors:

SB Athar, P Avery, L Breva-Newell, R Patel, V Potlia, H Stoeck, J Yelton, P Rubin, C Cawlfield, BI Eisenstein, GD Gollin, I Karliner, D Kim, N Lowrey, P Naik, C Sedlack, M Selen, EJ White, J Williams, J Wiss, DM Asner, KW Edwards, D Besson, TK Pedlar, D Cronin-Hennessy, KY Gao, DT Gong, J Hietala, Y Kubota, T Klein, BW Lang, SZ Li, R Poling, AW Scott, A Smith, S Dobbs, Z Metreveli, KK Seth, A Tomaradze, P Zweber, J Ernst, K Arms, H Severini, SA Dytman, W Love, S Mehrabyan, JA Mueller, V Savinov, Z Li, A Lopez, H Mendez, J Ramirez, GS Huang, DH Miller, V Pavlunin, B Sanghi, IPJ Shipsey, GS Adams, M Cravey, JP Cummings, I Danko, J Napolitano, Q He, H Muramatsu, CS Park, EH Thorndike, TE Coan, YS Gao, F Liu, R Stroynowski, M Artuso, C Boulahouache, S Blusk, J Butt, O Dorjkhaidav, J Li, N Menaa, R Mountain, R Nandakumar, K Randrianarivony, R Redjimi, R Sia, T Skwarnicki, S Stone, JC Wang, K Zhang, SE Csorna, G Bonvicini, D Cinabro, M Dubrovin, A Bornheim, SP Pappas, AJ Weinstein, RA Briere, GP Chen, J Chen, T Ferguson, G Tatishvili, H Vogel, ME Watkins

Abstract:

Using data obtained with the CLEO III detector, running at the Cornell Electron Storage Ring (CESR), we report on a new study of exclusive radiative Υ(1S) decays into the final states γπ+π-, γK+K-, and γpp̄. We present branching ratio measurements for the decay modes Υ(1S)→γf2(1270), Υ(1S)→γf2′(1525), and Υ(1S)→γK+K-; helicity production ratios for f2(1270) and f2′(1525); upper limits for the decay Υ(1S)→γfJ(2200), with fJ(2220)→π+π-, K+K-, pp̄; and an upper limit for the decay Υ(1S)→γX(1860), with X(1860)→γpp̄. © 2006 The American Physical Society.
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Top quark mass measurement using the template method in the lepton+jets channel at CDF II

Physical Review D Particles Fields Gravitation and Cosmology 73:3 (2006)

Authors:

A Abulencia, D Acosta, J Adelman, T Affolder, T Akimoto, MG Albrow, D Ambrose, S Amerio, D Amidei, A Anastassov, K Anikeev, A Annovi, J Antos, M Aoki, G Apollinari, JF Arguin, T Arisawa, A Artikov, W Ashmanskas, A Attal, F Azfar, P Azzi-Bacchetta, P Azzurri, N Bacchetta, H Bachacou, W Badgett, A Barbaro-Galtieri, VE Barnes, BA Barnett, S Baroiant, V Bartsch, G Bauer, F Bedeschi, S Behari, S Belforte, G Bellettini, J Bellinger, A Belloni, E Ben-Haim, D Benjamin, A Beretvas, J Beringer, T Berry, A Bhatti, M Binkley, D Bisello, M Bishai, RE Blair, C Blocker, K Bloom, B Blumenfeld, A Bocci, A Bodek, V Boisvert, G Bolla, A Bolshov, D Bortoletto, J Boudreau, S Bourov, A Boveia, B Brau, C Bromberg, E Brubaker, J Budagov, HS Budd, S Budd, K Burkett, G Busetto, P Bussey, KL Byrum, S Cabrera, M Campanelli, M Campbell, F Canelli, A Canepa, D Carlsmith, R Carosi, S Carron, M Casarsa, A Castro, P Catastini, D Cauz, M Cavalli-Sforza, A Cerri, L Cerrito, SH Chang, J Chapman, YC Chen, M Chertok, G Chiarelli, G Chlachidze, F Chlebana, I Cho, K Cho, D Chokheli, JP Chou, PH Chu, SH Chuang, K Chung, WH Chung

Abstract:

This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and antiprotons at Fermilab's Tevatron (s=1.96TeV) produce top/antitop pairs, which decay to W+W-bb̄; events are selected where one W decays to hadrons and the other W decays to either e or μ plus a neutrino. The data sample corresponds to an integrated luminosity of approximately 318pb-1. A total of 165 tt̄ events are separated into four subsamples based on jet transverse energy thresholds and the number of b jets identified by reconstructing a displaced vertex. In each event, the reconstructed top quark invariant mass is determined by minimizing a χ2 for the overconstrained kinematic system. At the same time, the mass of the hadronically decaying W boson is measured in the same event sample. The observed W boson mass provides an in situ improvement in the determination of the hadronic jet energy scale. A simultaneous likelihood fit of the reconstructed top quark masses and the W boson invariant masses in the data sample to distributions from simulated signal and background events gives a top quark mass of 173.5-3.8+3.9GeV/c2. © 2006 The American Physical Society.
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