First detection of the Sunyaev Zel'dovich effect increment at λ < 650 μm

• Published in: Astronomy and astrophysics (Berlin) 2010-07, Vol.518 (1), p.L16
• Main Authors: Zemcov, M., Rex, M., Rawle, T. D., Bock, J. J., Egami, E., Altieri, B., Blain, A. W., Boone, F., Bridge, C. R., Clement, B., Combes, F., Dowell, C. D., Dessauges-Zavadsky, M., Fadda, D., Ilbert, O., Ivison, R. J., Jauzac, M., Kneib, J.-P., Lutz, D., Pelló, R., Pereira, M. J., Pérez-González, P. G., Richard, J., Rieke, G. H., Rodighiero, G., Schaerer, D., Smith, G. P., Valtchanov, I., Walth, G. L., van der Werf, P., Werner, M. W.
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics; cosmic background radiation; Cosmology and Extra-Galactic Astrophysics; Earth, ocean, space; Exact sciences and technology; galaxies: clusters: individual: 1E0657-56; Physics; Sciences of the Universe
• ISSN: 0004-6361; 1432-0746; 1432-0756
• DOI: 10.1051/0004-6361/201014685

The Sunyaev-Zel'dovich (SZ) effect is a spectral distortion of the cosmic microwave background as observed through the hot plasma in galaxy clusters. This distortion is a decrement in the CMB intensity for λ > 1.3 mm, an increment at shorter wavelengths, and small again by λ ~ 250 μm. As part of the Herschel Lensing Survey (HLS) we have mapped 1E0657–56 (the Bullet cluster) with SPIRE with bands centered at 250, 350 and 500 μm and have detected the SZ effect at the two longest wavelengths. The measured SZ effect increment central intensities are ΔI0 = 0.097 ± 0.019 MJy sr-1 at 350 μm and ΔI0 = 0.268 ± 0.031 MJy sr-1 at 500 μm, consistent with the SZ effect spectrum derived from previous measurements at 2 mm. No other diffuse emission is detected. The presence of the finite temperature SZ effect correction is preferred by the SPIRE data at a significance of 2.1σ, opening the possibility that the relativistic SZ effect correction can be constrained by SPIRE in a sample of clusters. The results presented here have important ramifications for both sub-mm measurements of galaxy clusters and blank field surveys with SPIRE.