%0 Generic %1 valentino2016giant %A Valentino, F. %A Daddi, E. %A Finoguenov, A. %A Strazzullo, V. %A Brun, A. M. C. Le %A Vignali, C. %A Bournaud, F. %A Dickinson, M. %A Renzini, A. %A Béthermin, M. %A Zanella, A. %A Gobat, R. %A Cimatti, A. %A Elbaz, D. %A Onodera, M. %A Pannella, M. %A Sargent, M. T. %A Arimoto, N. %A Carollo, M. %A Starck, J-L. %D 2016 %K cluster core extended nebula outflows %T A giant Ly$\alpha$ nebula in the core of an X-ray cluster at $z=1.99$: implications for early energy injection %U http://arxiv.org/abs/1605.03194 %X We present the discovery of a giant $\gtrsim$100 kpc Ly$\alpha$ nebula detected in the core of the X-ray emitting cluster CL J1449+0856 at $z=1.99$ through Keck/LRIS narrow-band imaging. This detection extends the known relation between Ly$\alpha$ nebulae and overdense regions of the Universe to the dense core of a $5-7\times10^13$ M$_ødot$ cluster. The most plausible candidates to power the nebula are two Chandra-detected AGN host cluster members. Given the physical conditions of the Ly$\alpha$-emitting gas and the possible interplay with the X-ray phase, we argue that the Ly$\alpha$ nebula would be short-lived ($łesssim10$ Myr) if not continuously replenished with cold gas at a rate of $\gtrsim1000$ Myr. Cooling from the X-ray phase is disfavored as the replenishing mechanism, primarily because of the high Ly$\alpha$ to X-ray luminosity ratio ($L_Ly\alpha/L_X \approx0.3$), $\gtrsim10-1000\times$ higher than in local cool-core clusters. Cosmological cold flows are disfavored by current modeling. Thus, the cold gas is most plausibly supplied by cluster galaxies through massive outflows. An independent estimate of the total mass outflow rate of core members, based on the observed star formation and black hole accretion rates, matches the required replenishment to sustain the nebula. This scenario directly implies the extraction of energy from galaxies and its deposition in the surrounding intracluster medium, as required to explain the thermodynamic properties of local clusters. We estimate an energy injection of the order of $þickapprox2$ keV per particle in the intracluster medium over a $2$ Gyr interval. AGN provide $75-85$% of the injected energy and $\approx66$% of the mass, while the rest is supplied by supernovae-driven winds.

@misc{valentino2016giant, abstract = {We present the discovery of a giant $\gtrsim$100 kpc Ly$\alpha$ nebula detected in the core of the X-ray emitting cluster CL J1449+0856 at $z=1.99$ through Keck/LRIS narrow-band imaging. This detection extends the known relation between Ly$\alpha$ nebulae and overdense regions of the Universe to the dense core of a $5-7\times10^{13}$ M$_{\odot}$ cluster. The most plausible candidates to power the nebula are two Chandra-detected AGN host cluster members. Given the physical conditions of the Ly$\alpha$-emitting gas and the possible interplay with the X-ray phase, we argue that the Ly$\alpha$ nebula would be short-lived ($\lesssim10$ Myr) if not continuously replenished with cold gas at a rate of $\gtrsim1000$ Myr. Cooling from the X-ray phase is disfavored as the replenishing mechanism, primarily because of the high Ly$\alpha$ to X-ray luminosity ratio ($L_{\mathrm{Ly\alpha}}/L_{\mathrm{X}} \approx0.3$), $\gtrsim10-1000\times$ higher than in local cool-core clusters. Cosmological cold flows are disfavored by current modeling. Thus, the cold gas is most plausibly supplied by cluster galaxies through massive outflows. An independent estimate of the total mass outflow rate of core members, based on the observed star formation and black hole accretion rates, matches the required replenishment to sustain the nebula. This scenario directly implies the extraction of energy from galaxies and its deposition in the surrounding intracluster medium, as required to explain the thermodynamic properties of local clusters. We estimate an energy injection of the order of $\thickapprox2$ keV per particle in the intracluster medium over a $2$ Gyr interval. AGN provide $75-85$% of the injected energy and $\approx66$% of the mass, while the rest is supplied by supernovae-driven winds.}, added-at = {2016-05-12T10:22:06.000+0200}, author = {Valentino, F. and Daddi, E. and Finoguenov, A. and Strazzullo, V. and Brun, A. M. C. Le and Vignali, C. and Bournaud, F. and Dickinson, M. and Renzini, A. and Béthermin, M. and Zanella, A. and Gobat, R. and Cimatti, A. and Elbaz, D. and Onodera, M. and Pannella, M. and Sargent, M. T. and Arimoto, N. and Carollo, M. and Starck, J-L.}, biburl = {https://www.bibsonomy.org/bibtex/2d26798f24328a60e5eeb6fb9cee1a51a/miki}, description = {[1605.03194] A giant Ly$\alpha$ nebula in the core of an X-ray cluster at $z=1.99$: implications for early energy injection}, interhash = {effe290666efe63259d9fe6613385ba3}, intrahash = {d26798f24328a60e5eeb6fb9cee1a51a}, keywords = {cluster core extended nebula outflows}, note = {cite arxiv:1605.03194Comment: 15 pages, 10 figures, 1 appendix. Resubmitted to ApJ after referee reports}, timestamp = {2016-05-12T10:22:06.000+0200}, title = {A giant Ly$\alpha$ nebula in the core of an X-ray cluster at $z=1.99$: implications for early energy injection}, url = {http://arxiv.org/abs/1605.03194}, year = 2016 }