2007ApJ...668L...5B

We have searched for IR emission from the intracluster dust (ICD) in the galaxy cluster A2029. Weak signals of enhanced extended emission in the cluster are detected at 24 and 70 µm. However, the signals are indistinguishable from the foreground fluctuations. The 24 µm versus 70 µm color map does not discriminate the dust emission in the cluster from the cirrus emission. After excluding the contamination from the point sources, we obtain upper limits for the extended ICD emission in A2029, 5x10³ Jy/sr at 24 µm and 5x10⁴ Jy/sr at 70 µm. The upper limits are generally consistent with the expectation from theoretical calculations and support a dust deficiency in the cluster compared to the interstellar medium (ISM) of our Galaxy. Our results suggest that even with the much improved sensitivity of current IR telescopes, a clear detection of the IR emission from ICD may be difficult due to cirrus noise.