%0 Generic %1 dalton2021probing %A Dalton, Tony %A Morris, Simon L. %A Fumagalli, Michele %A Gatuzz, Efrain %D 2021 %K library %T Probing the physical properties of the intergalactic medium using blazars %U http://arxiv.org/abs/2109.06632 %X We use Swift blazar spectra to estimate the key intergalactic medium (IGM) properties of hydrogen column density(Nhxigm), metallicity and temperature over a redshift range of 0.03 leq z leq 4.7, using a collisional ionisation equilibrium(CIE) model for the ionised plasma. We adopted a conservative approach to the blazar continuum model given its intrinsic variability and use a range of power law models. We subjected our results to a number of tests and found that the Nhxigm parameter was robust with respect to individual exposure data and co-added spectra for each source, and between Swift and XMM-Newton source data. We also found no relation between Nhxigm and variations in source flux or intrinsic power laws. Though some objects may have a bulk Comptonisation component which could mimic absorption, it did not alter our overall results. The Nhxigm from the combined blazar sample scales as(1+z)^1.8+\-0.2. The mean hydrogen density at z = 0 is n0 = (3.2+\-0.5) x 10^-7 cm^-3. The mean IGM temperature over the full redshift range is log(T\K) = 6.1+\-0.1 and the mean metallicity is X\H = -1.62+\-0.04 (Z sim0.02) When combining with the results with a gamma-ray burst (GRB) sample, we find the results are consistent over an extended redshift range of 0.03 leq z leq 6.3. Using our model for blazars and GRBs, we conclude that the IGM contributes substantially to the total absorption seen in both blazar and GRB spectra.

@misc{dalton2021probing, abstract = {We use Swift blazar spectra to estimate the key intergalactic medium (IGM) properties of hydrogen column density(Nhxigm), metallicity and temperature over a redshift range of 0.03 leq z leq 4.7, using a collisional ionisation equilibrium(CIE) model for the ionised plasma. We adopted a conservative approach to the blazar continuum model given its intrinsic variability and use a range of power law models. We subjected our results to a number of tests and found that the Nhxigm parameter was robust with respect to individual exposure data and co-added spectra for each source, and between Swift and XMM-Newton source data. We also found no relation between Nhxigm and variations in source flux or intrinsic power laws. Though some objects may have a bulk Comptonisation component which could mimic absorption, it did not alter our overall results. The Nhxigm from the combined blazar sample scales as(1+z)^1.8+\-0.2. The mean hydrogen density at z = 0 is n0 = (3.2+\-0.5) x 10^-7 cm^-3. The mean IGM temperature over the full redshift range is log(T\K) = 6.1+\-0.1 and the mean metallicity is [X\H] = -1.62+\-0.04 (Z sim0.02) When combining with the results with a gamma-ray burst (GRB) sample, we find the results are consistent over an extended redshift range of 0.03 leq z leq 6.3. Using our model for blazars and GRBs, we conclude that the IGM contributes substantially to the total absorption seen in both blazar and GRB spectra.}, added-at = {2021-09-15T15:12:09.000+0200}, author = {Dalton, Tony and Morris, Simon L. and Fumagalli, Michele and Gatuzz, Efrain}, biburl = {https://www.bibsonomy.org/bibtex/28d4ea4f697eba23f669342ae8fd32ccd/gpkulkarni}, description = {Probing the physical properties of the intergalactic medium using blazars}, interhash = {336790d385c513bfb942ba7aa01797b5}, intrahash = {8d4ea4f697eba23f669342ae8fd32ccd}, keywords = {library}, note = {cite arxiv:2109.06632Comment: Accepted for publication by the MNRAS. arXiv admin note: text overlap with arXiv:2102.02530}, timestamp = {2021-09-15T15:12:09.000+0200}, title = {Probing the physical properties of the intergalactic medium using blazars}, url = {http://arxiv.org/abs/2109.06632}, year = 2021 }