The SRG/eROSITA all-sky survey. X-ray emission from the warm-hot phase gas in long cosmic filaments

Fuente: arXiv
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Autori principali: Zhang, X., Bulbul, E., Malavasi, N., Ghirardini, V., Comparat, J., Kluge, M., Liu, A., Merloni, A., Zhang, Y., Bahar, Y. E., Artis, E., Sanders, J. S., Garrel, C., Balzer, F., Brüggen, M., Freyberg, M., Gatuzz, E., Grandis, S., Krippendorf, S., Nandra, K., Ponti, G., Ramos-Ceja, M., Predehl, P., Reiprich, T. H., Veronica, A., Yeung, M. C. H., Zelmer, S.
Natura: Preprint
Pubblicazione: 2024
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author Zhang, X.
Bulbul, E.
Malavasi, N.
Ghirardini, V.
Comparat, J.
Kluge, M.
Liu, A.
Merloni, A.
Zhang, Y.
Bahar, Y. E.
Artis, E.
Sanders, J. S.
Garrel, C.
Balzer, F.
Brüggen, M.
Freyberg, M.
Gatuzz, E.
Grandis, S.
Krippendorf, S.
Nandra, K.
Ponti, G.
Ramos-Ceja, M.
Predehl, P.
Reiprich, T. H.
Veronica, A.
Yeung, M. C. H.
Zelmer, S.
author_facet Zhang, X.
Bulbul, E.
Malavasi, N.
Ghirardini, V.
Comparat, J.
Kluge, M.
Liu, A.
Merloni, A.
Zhang, Y.
Bahar, Y. E.
Artis, E.
Sanders, J. S.
Garrel, C.
Balzer, F.
Brüggen, M.
Freyberg, M.
Gatuzz, E.
Grandis, S.
Krippendorf, S.
Nandra, K.
Ponti, G.
Ramos-Ceja, M.
Predehl, P.
Reiprich, T. H.
Veronica, A.
Yeung, M. C. H.
Zelmer, S.
contents The properties of the warm-hot intergalactic medium (WHIM) in cosmic filaments are among the least quantified units in modern astrophysics. The Spectrum Roentgen Gamma/eROSITA All Sky Survey ((SRG/eRASS) provides a unique opportunity to study the X-ray emission of the WHIM. We applied both imaging and spectroscopic stacking techniques to the data of the first four eRASS scans to inspect the X-ray emissions from 7817 cosmic filaments identified from Sloan Digital Sky Survey (SDSS) optical galaxy samples. We obtained a $9σ$ significant detection of the total X-ray signal from filaments in the 0.3--1.2~keV band. Here, we introduce a novel method to estimate the contamination fraction from unmasked X-ray halos, active galactic nuclei, and X-ray binaries associated with filament galaxies. We found an approximately 40\% contamination fraction for these unmasked sources, suggesting that the remaining 60\% of the signal could be coming from the WHIM and a $5.4σ$ detection significance of the WHIM. Moreover, we modeled the temperature and baryon density contrast of the detected WHIM by fitting the stacked spectrum and surface brightness profile. The best-fit temperature $\log(T/\mathrm{K})=6.84\pm0.07$, obtained by using a single temperature model, is marginally higher than in the simulation results. This could be due to the fitting of a single temperature model on a multi-temperature spectrum. Assuming a 0.2 solar abundance, the best-fit baryon density contrast $\logΔ_\mathrm{b}=1.88\pm0.18$ is in general agreement with the X-ray emitting phases in the IllustrisTNG simulation. This result suggests that the broadband X-ray emission traces the high end of the temperature and density values that characterize the entire WHIM population.
format Preprint
id arxiv_https___arxiv_org_abs_2406_00105
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The SRG/eROSITA all-sky survey. X-ray emission from the warm-hot phase gas in long cosmic filaments
Zhang, X.
Bulbul, E.
Malavasi, N.
Ghirardini, V.
Comparat, J.
Kluge, M.
Liu, A.
Merloni, A.
Zhang, Y.
Bahar, Y. E.
Artis, E.
Sanders, J. S.
Garrel, C.
Balzer, F.
Brüggen, M.
Freyberg, M.
Gatuzz, E.
Grandis, S.
Krippendorf, S.
Nandra, K.
Ponti, G.
Ramos-Ceja, M.
Predehl, P.
Reiprich, T. H.
Veronica, A.
Yeung, M. C. H.
Zelmer, S.
High Energy Astrophysical Phenomena
Cosmology and Nongalactic Astrophysics
The properties of the warm-hot intergalactic medium (WHIM) in cosmic filaments are among the least quantified units in modern astrophysics. The Spectrum Roentgen Gamma/eROSITA All Sky Survey ((SRG/eRASS) provides a unique opportunity to study the X-ray emission of the WHIM. We applied both imaging and spectroscopic stacking techniques to the data of the first four eRASS scans to inspect the X-ray emissions from 7817 cosmic filaments identified from Sloan Digital Sky Survey (SDSS) optical galaxy samples. We obtained a $9σ$ significant detection of the total X-ray signal from filaments in the 0.3--1.2~keV band. Here, we introduce a novel method to estimate the contamination fraction from unmasked X-ray halos, active galactic nuclei, and X-ray binaries associated with filament galaxies. We found an approximately 40\% contamination fraction for these unmasked sources, suggesting that the remaining 60\% of the signal could be coming from the WHIM and a $5.4σ$ detection significance of the WHIM. Moreover, we modeled the temperature and baryon density contrast of the detected WHIM by fitting the stacked spectrum and surface brightness profile. The best-fit temperature $\log(T/\mathrm{K})=6.84\pm0.07$, obtained by using a single temperature model, is marginally higher than in the simulation results. This could be due to the fitting of a single temperature model on a multi-temperature spectrum. Assuming a 0.2 solar abundance, the best-fit baryon density contrast $\logΔ_\mathrm{b}=1.88\pm0.18$ is in general agreement with the X-ray emitting phases in the IllustrisTNG simulation. This result suggests that the broadband X-ray emission traces the high end of the temperature and density values that characterize the entire WHIM population.
title The SRG/eROSITA all-sky survey. X-ray emission from the warm-hot phase gas in long cosmic filaments
topic High Energy Astrophysical Phenomena
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2406.00105