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تسجيل مستخدم جديدStarbursting Brightest Cluster Galaxy: a Herschel view of the massive cluster MACS J1931.8-2634
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We investigate the dust-obscured star formation properties of the massive, X-ray selected galaxy cluster MACS J1931.8-2634 at $z$=0.352. Using far-infrared (FIR) imaging in the range 100-500$mu$m obtained with the textit{Herschel} telescope, we extract 31 sources (2$sigma$) within $rsim$1 Mpc from the brightest cluster galaxy (BCG). Among these sources we identify six cluster members for which we perform an analysis of their spectral energy distributions (SEDs). We measure total infrared luminosity (L$_{IR}$), star formation rate (SFR) and dust temperature. The BCG, with L$_{IR}$=1.4$times$10$^{12}$L$_odot$ is an Ultra Luminous Infrared Galaxy and hosts a type II AGN. We decompose its FIR SED into AGN and starburst components and find equal contributions from AGN and starburst. We also recompute the SFR of the BCG finding SFR=150$pm$15 M$_odot$yr$^{-1}$. We search for an isobaric cooling flow in the cool core using {sl Chandra} X-ray data, and find no evidence for gas colder than 1.8 keV in the inner 30 kpc, for an upper limit to the istantaneous mass-deposition rate of 58 M$_odot$yr$^{-1}$ at 95 % c.l. This value is $3times$ lower than the SFR in the BCG, suggesting that the on-going SF episode lasts longer than the ICM cooling events.
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In this paper we present results from a radio-optical study of the galaxy populations of the galaxy clusters Abell 1300 and MACS J1931.8$-$2634, a merger and a relaxed system respectively both located at $z sim 0.3$, aimed at finding evidence of merg
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We report on a deep, multiwavelength study of the galaxy cluster MACS J1931.8-2634 using Chandra X-ray, Subaru optical, and VLA 1.4 GHz radio data. This cluster (z=0.352) harbors one of the most X-ray luminous cool cores yet discovered, with an equiv
alent mass cooling rate within the central 50 kpc is approximately 700 solar masses/yr. Unique features observed in the central core of MACSJ1931.8-2634 hint to a wealth of past activity that has greatly disrupted the original cool core. We observe a spiral of relatively cool, dense, X-ray emitting gas connected to the cool core, as well as highly elongated intracluster light (ICL) surrounding the cD galaxy. Extended radio emission is observed surrounding the central AGN, elongated in the east-west direction, spatially coincident with X-ray cavities. The power input required to inflate these `bubbles is estimated from both the X-ray and radio emission to reside between 4 and 14e45 erg/s, putting it among the most powerful jets ever observed. This combination of a powerful AGN outburst and bulk motion of the cool core have resulted in two X-ray bright ridges to form to the north and south of the central AGN at a distance of approximately 25 kpc. The northern ridge has spectral characteristics typical of cool cores and is consistent with being a remnant of the cool core after it was disrupted by the AGN and bulk motions. It is also the site of H-alpha filaments and young stars. The X-ray spectroscopic cooling rate associated with this ridge is approximately 165 solar masses/yr, which agrees with the estimate of the star formation rate from broad-band optical imaging (170 solar masses/yr). MACS J1931.8-2634 appears to harbor one of most profoundly disrupted low entropy cores observed in a cluster, and offers new insights into the survivability of cool cores in the context of hierarchical structure formation.
We reveal the importance of ongoing in-situ star formation in the Brightest Cluster Galaxy in the massive cool-core CLASH cluster MACS 1931.8-2635 at z=0.35. Using a multi-wavelength approach, we assess the stellar and warm ionized medium components,
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