High Spectral Resolution Measurement of the Sunyaev-Zel'dovich Effect Null with Z-Spec
| Autor: | Zemcov, M., Aguirre, J., Bock, J., Bradford, M., Czakon, N., Glenn, J., Golwala, S. R., Lupu, R., Maloney, P., Mauskopf, P., Million, E., Murphy, E. J., Naylor, B., Nguyen, H., Rosenman, M., Sayers, J., Scott, K. S., Zmuidzinas, J. |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal, Volume 749, Issue 2, article id. 114, 13 pp. (2012) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1088/0004-637X/749/2/114 |
| Popis: | The Sunyaev-Zel'dovich (SZ) effect spectrum crosses through a null where dT_CMB = 0 near nu_0 = 217 GHz. In a cluster of galaxies, nu_0 can be shifted from the canonical thermal SZ effect value by corrections to the SZ effect scattering due to the properties of the inter-cluster medium. We have measured the SZ effect in the hot galaxy cluster RX J1347.5-1145 with Z-Spec, an R ~ 300 grating spectrometer sensitive between 185 and 305 GHz. These data comprise a high spectral resolution measurement around the null of the SZ effect and clearly exhibit the transition from negative to positive dT_CMB over the Z-Spec band. The SZ null position is measured to be nu_0 = 225.8 \pm 2.5 (stat.) \pm 1.2 (sys.) GHz, which differs from the canonical null frequency by 3.0 sigma and is evidence for modifications to the canonical thermal SZ effect shape. Assuming the measured shift in nu_0 is due only to relativistic corrections to the SZ spectrum, we place the limit T_e = 17.1 \pm 5.3 keV from the zero-point measurement alone. By simulating the response of the instrument to the sky, we are able to generate likelihood functions in {y_0, T_e, v_pec} space. For v_pec = 0 km/s, we measure the best fitting SZ model to be y_0 = 4.6 (+0.6, -0.9) x 10^-4, T_e,0 = 15.2 (+12,-7.4) keV. When v_pec is allowed to vary, a most probable value of v_pec = +450 \pm 810 km/s is found. Comment: 15 pages, 12 figures, matches version published in April 2012 ApJ |
| Databáze: | arXiv |
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