Detection of Metal-Rich, Cool-Warm Gas in the Outskirts of Galaxy Clusters

التفاصيل البيبلوغرافية
العنوان: Detection of Metal-Rich, Cool-Warm Gas in the Outskirts of Galaxy Clusters
المؤلفون: Pradeep, Jayadev, Narayanan, Anand, Muzahid, Sowgat, Nagai, Daisuke, Charlton, Jane C., Srianand, Raghunathan
سنة النشر: 2019
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Astrophysics of Galaxies
الوصف: We present an ultraviolet quasar absorption line analysis of metal lines associated with three strong intervening H I absorbers (with $N$(H I) $>$ 10$^{16.5}$ cm$^{-2}$) detected in the outskirts of Sunyaev-Zel'dovich (SZ) effect-selected galaxy clusters ($z_{\rm cl} \sim 0.4 - 0.5$), within clustocentric impact parameters of $\rho_{cl}$ $\sim$ $(1.6 - 4.7)r_{500}$. Discovered in a recent set of targeted far-UV $HST$/COS spectroscopic observations, these absorbers have the highest H I column densities ever observed in the outskirts of galaxy clusters, and are also rich in metal absorption lines. Photoionization models yield single phase solutions for the three absorbers with gas densities of $n_{H} \sim 10^{-3} - 10^{-4}$ cm$^{-3}$ and metallicities of [X/H] $>$ -1.0 (from one-tenth solar to near-solar). The widths of detected absorption lines suggest gas temperatures of $T \sim 10^4$ K. The inferred densities (temperatures) are significantly higher (lower) compared to the X-ray emitting intracluster medium in cluster cores. The absorbers are tracing a cool phase of the intracluster gas in the cluster outskirts, either associated with gas stripped from cluster galaxies via outflows, tidal streams or ram-pressure forces, or denser regions within the intracluster medium that were uniformly chemically enriched from an earlier epoch of enhanced supernova and AGN feedback.
Comment: 13 pages, 6 figures, 2 tables. Accepted for publication in MNRAS
نوع الوثيقة: Working Paper
DOI: 10.1093/mnras/stz2059
URL الوصول: http://arxiv.org/abs/1907.10733
رقم الانضمام: edsarx.1907.10733
قاعدة البيانات: arXiv