TY - JOUR
T1 - Sunyaev-Zel'dovich detection of the galaxy cluster Cl J1449+0856 at z=1.99
T2 - The pressure profile in uv space
AU - Gobat, R.
AU - Daddi, Emanuele
AU - Coogan, R. T.
AU - Le Brun, Matthieu
AU - Bournaud, F.
AU - Melin, J.-B
AU - Riechers, D.
AU - Sargent, M.
AU - Valentino, Francesco Maria
AU - Hwang, Helena
AU - Finoguenov, Alexis
AU - Strazzullo, Veronica
PY - 2019/9/1
Y1 - 2019/9/1
N2 - 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 5σ significance. The total signal is -190 ± 36 μJy, 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 × 1013M⊙ 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 that 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.
AB - 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 5σ significance. The total signal is -190 ± 36 μJy, 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 × 1013M⊙ 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 that 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.
U2 - 10.1051/0004-6361/201935862
DO - 10.1051/0004-6361/201935862
M3 - Journal article
SN - 0004-6361
VL - 629
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A104
ER -