Mapping the X-ray Sky with SRG: First Results from eROSITA and ART-XC Contribution ID : 130 Type : Poster eROSITA/XMM-Newton/Suzaku Cluster Temperature Cross-Calibration with the UGC03957 Galaxy Cluster eROSITA will provide new data to further investigate Dark Energy and therefore the accelerated expansion of our Universe. The eROSITA telescope will observe about 50-100 thousand galaxy clusters within its journey. The X-ray emission of the hot intergalactic medium of these clusters provides information about thetemper- ature and facilitates the study of their large scale distribution. In order to be able to make a qualified data analysis the calibration of the eROSITA telescope needs to beval- idated first. One route to this is the cross-calibration with other X-ray telescopes using non-variable sources like galaxy clusters. For this purpose the low temperature galaxy cluster UGC03957 was observed in the initial phase of data recording. In this project the temperature profile of the UGC03957 galaxy cluster is extracted from the eROSITA data. Therefore, the data is cleaned by removing e.g. particle flare contaminated events and masking the X-ray point sources in the extraction area. The area around the cluster center is divided into several annuli and a model is fitted to the corresponding energy spectrum of each annulus. The obtained temperature profile is compared to the results of the XMM-Newton and Suzaku data. First analysis results indicate good agreement amongst the telescopes. Presenter status eROSITA consortium member Primary author(s) : ASCHERSLEBEN, Jann Co-author(s) : REIPRICH, Thomas H. (AIfA, University of; Bonn) PACAUD, Florian (AIfA, University of Bonn); WHELAN, Beibhinn; VERONICA, Angie (AIfA); ILJENKAREVIC, Jana (AIfA, University of Bonn); Dr BULBUL, Esra (MPE) Presenter(s) : ASCHERSLEBEN, Jann.