Purpose Many X-ray astronomical observatories are dedicated to observing cosmic phenomena such as galaxy clusters,which inevitably involves the influence of background.When observing the universe,there are mainly two ...Purpose Many X-ray astronomical observatories are dedicated to observing cosmic phenomena such as galaxy clusters,which inevitably involves the influence of background.When observing the universe,there are mainly two types of background:the cosmic X-ray background and the particle background,known as non-X-ray background.Understanding the variation of the particle background is crucial for the observations made by the Einstein Probe(EP)satellite.Methods In order to simulate the observation effects of EP-FXT,this paper utilized fixed-point observation data obtained from eROSITA’s Performance Verification phase and Filter Wheel Closed data to construct a background model.Subsequently,based on the eROSITA background model,an EP-FXT background model was established.Due to the different orbits,the particle background of eROSITA is about seven times that of EP-FXT.Based on this,a comparison was made between the high-particle-background model and the low-particle-background model in the observation of galaxy clusters.Results The results indicate that,without systematic errors,a high background leads to a 20%increase in the errors of the fitting parameter.Conclusions The impact of systematic errors is more pronounced in observations with high particle backgrounds.Additionally,the low particle background demonstrates clear advantages in the fitting of temperature and metallicity parameters,with this advantage becoming more significant as the temperature and metallicity increase.展开更多
The calibration database(CALDB)for the Einstein probe’s follow-up X-ray telescope(EP-FXT)is designed to store essential calibration files such as point spread function(PSF)files,vignetting files,ancillary response fi...The calibration database(CALDB)for the Einstein probe’s follow-up X-ray telescope(EP-FXT)is designed to store essential calibration files such as point spread function(PSF)files,vignetting files,ancillary response files(ARFs),and response matrix files(RMFs).These files are essential to ensure the accuracy and reliability of scientific data analysis.We adopt a structured approach to organize the calibration data by using standardized file naming conventions and formats.Each file type includes specific extensions and binary tables to capture detailed calibration parameters.For example,the ancillary response file contains energy and effective area data,while the response matrix file includes response functions and energy-channel relationships.Keywords are systematically embedded within calibration files in the CALDB to support efficient indexing and retrieval.The calibration database successfully supports the diverse calibration requirements of EP-FXT,accommodating various observation modes and filters.It provides a robust framework for storing,retrieving,and updating calibration data,significantly reducing systematic errors in data analysis.The design ensures scalability and adaptability,allowing for future enhancements.By maintaining high calibration data integrity and accessibility,the database plays a critical role in maximizing the scientific return from EP-FXT observations,enabling precise calibration across different observational scenarios.展开更多
基金supported by the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences,Grant No.XDA15310103.
文摘Purpose Many X-ray astronomical observatories are dedicated to observing cosmic phenomena such as galaxy clusters,which inevitably involves the influence of background.When observing the universe,there are mainly two types of background:the cosmic X-ray background and the particle background,known as non-X-ray background.Understanding the variation of the particle background is crucial for the observations made by the Einstein Probe(EP)satellite.Methods In order to simulate the observation effects of EP-FXT,this paper utilized fixed-point observation data obtained from eROSITA’s Performance Verification phase and Filter Wheel Closed data to construct a background model.Subsequently,based on the eROSITA background model,an EP-FXT background model was established.Due to the different orbits,the particle background of eROSITA is about seven times that of EP-FXT.Based on this,a comparison was made between the high-particle-background model and the low-particle-background model in the observation of galaxy clusters.Results The results indicate that,without systematic errors,a high background leads to a 20%increase in the errors of the fitting parameter.Conclusions The impact of systematic errors is more pronounced in observations with high particle backgrounds.Additionally,the low particle background demonstrates clear advantages in the fitting of temperature and metallicity parameters,with this advantage becoming more significant as the temperature and metallicity increase.
基金supported by the Einstein-Probe(EP)Program which is funded by the Strategic Priority Research Program of the Chinese Academy of Sciences Grant No.XDA15310303.
文摘The calibration database(CALDB)for the Einstein probe’s follow-up X-ray telescope(EP-FXT)is designed to store essential calibration files such as point spread function(PSF)files,vignetting files,ancillary response files(ARFs),and response matrix files(RMFs).These files are essential to ensure the accuracy and reliability of scientific data analysis.We adopt a structured approach to organize the calibration data by using standardized file naming conventions and formats.Each file type includes specific extensions and binary tables to capture detailed calibration parameters.For example,the ancillary response file contains energy and effective area data,while the response matrix file includes response functions and energy-channel relationships.Keywords are systematically embedded within calibration files in the CALDB to support efficient indexing and retrieval.The calibration database successfully supports the diverse calibration requirements of EP-FXT,accommodating various observation modes and filters.It provides a robust framework for storing,retrieving,and updating calibration data,significantly reducing systematic errors in data analysis.The design ensures scalability and adaptability,allowing for future enhancements.By maintaining high calibration data integrity and accessibility,the database plays a critical role in maximizing the scientific return from EP-FXT observations,enabling precise calibration across different observational scenarios.
