Detection of a Multiphase Intragroup Medium: Results from the COS-IGrM Survey
| Autor: | Tyler McCabe, Sanchayeeta Borthakur, Timothy Heckman, Jason Tumlinson, Rongmon Bordoloi, Romeel Dave |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal. 923:189 |
| ISSN: | 1538-4357 0004-637X |
| Popis: | We present the results of the COS Intragroup Medium (COS-IGrM) Survey that used the Cosmic Origins Spectrograph on the Hubble Space Telescope to observe a sample of 18 UV bright quasars, each probing the intragroup medium (IGrM) of a galaxy group. We detect Ly$\alpha$, C II, N V, Si II, Si III, and O VI in multiple sightlines. The highest ionization species detected in our data is O VI, which was detected in 8 out of 18 quasar sightlines. The wide range of ionization states observed provide evidence that the IGrM is patchy and multiphase. We find that the O VI detections generally align with radiatively cooling gas between $10^{5.8}$ and $10^6$ K. The lack of O VI detections in 10 of the 18 groups illustrates that O VI may not be the ideal tracer of the volume filling component of the IGrM. Instead, it either exists at trace levels in a hot IGrM or is generated in the boundary between the hotter IGrM and cooler gas. Comment: 29 pages, 26 figures, accepted to ApJ |
| Databáze: | OpenAIRE |
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