Mapping the X-ray Sky with SRG: First Results from eROSITA and ART-XC

Soft Response Calibration with PSR B0656+14 Observations

Not scheduled

20m

Garching

Poster

Speaker

Beibhinn Whelan

Description

The response of the Chandra X-ray telescope in the soft band was recorded much lower than was initially expected before the launch. This depleted response has been documented to be deteriorating over time ever since and it is assumed to be due to the deposition of materials onto either the detector or the filters. The main science goal of eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is to perform a deep X-ray all sky survey, the first since ROSAT observations in 1990. It is important to understand the response of the telescopes over the large range of energies covered by eROSITA. In this sense, it is important to determine whether or not the telescope modules of eROSITA have been affected in a similar way as the Chandra space telescope. Before the commencement of the first stage of the all sky survey, a number of Performance Verification (PV) and calibration observations were carried out, the purpose of which included understanding and modelling the background, determining the contamination status and testing the camera performances. Using the PV observation of the Pulsar, PSR B0656+14, the event files and subsequent images, spectra and light curves of all cameras were compared to each other. Problems were found in telescope module 1 involving the presence of horizontal stripes on the images and the light curve produced was completely erratic. This indicated a problem with the camera electronics which led to the recommendation that the data from TM1 should not be used in any scientific analysis of this particular observation. Extracting the energy spectra and displaying all telescope modules in one plot, we can compare the response from each camera on eROSITA. The main goal of this work is to determine the presence or absence of contamination on the telescope modules which involves fitting a model to the energy spectra and forming a comparison of the residuals. This allows us to quantify the systematic differences between the instruments.