Sunyaev-Zel'dovich detection of the galaxy cluster Cl J1449+0856 at z = 1.99: the pressure profile in uv space

Gobat, R, Daddi, E, Coogan, R, Le Brun, A M C, Bournaud, F, Melin, J -B, Riechers, D A, Sargent, M, Valentino, F, Hwang, H S, Finoguenov, A and Strazzullo, V (2019) Sunyaev-Zel'dovich detection of the galaxy cluster Cl J1449+0856 at z = 1.99: the pressure profile in uv space. Astronomy and Astrophysics, 629 (A104). pp. 1-10. ISSN 0004-6361

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We present Atacama Large Millimetre Array and Atacama Compact Array observations of the Sunyaev-Zel'dovich effect in the z = 2 galaxy cluster Cl J1449+0856, an X-ray-detected progenitor of typical massive clusters in the present day Universe. While in a cleaned but otherwise untouched 92 GHz map of this cluster, little to no negative signal is visible, careful subtraction of known sub-millimetre emitters in the uv plane reveals a decrement at 5 σ significance. The total signal is -190 ± 36 μ Jy, with a peak offset by 5"-9" ( ∼ 50 kpc) from both the X-ray centroid and the still-forming brightest cluster galaxy. A comparison of the recovered uv-amplitude profile of the decrement with different pressure models allows us to derive total mass constraints consistent with the ∼ 6 × 10 13 M ⊙ estimated from X-ray data. Moreover, we find no strong evidence for a deviation of the pressure profile with respect to local galaxy clusters, although a slight tension at small-to-intermediate spatial scales suggests a flattened central profile, opposite to what seen in a cool core and possibly an AGN-related effect. This analysis of the lowest mass single SZ detection so far illustrates the importance of interferometers when observing the SZ effect in high-redshift clusters, the cores of which cannot be considered quiescent, such that careful subtraction of galaxy emission is necessary.

Item Type: Article
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Research Centres and Groups: Astronomy Centre
Subjects: Q Science > QB Astronomy
Depositing User: Mark Sargent
Date Deposited: 10 Sep 2019 15:11
Last Modified: 26 Apr 2021 15:15

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