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Jee, M. James,Dawson, William A.,Stroe, Andra,Wittman, David,van Weeren, Reinout J.,Brü,ggen, Marcus,Bradač,, Maruš,a,Rö,ttgering, Huub American Astronomical Society 2016 The Astrophysical journal Vol.817 No.2
<P>The galaxy cluster RX J0603.3+4214. at z-0.225 is one of the rarest clusters boasting an extremely large (similar to 2 Mpc) radio. relic. Because of the remarkable morphology of the relic, the cluster is nicknamed the. 'Toothbrush Cluster.' Although the cluster's underlying mass distribution is one of the critical pieces of information needed to reconstruct the merger scenario responsible for the puzzling radio. relic morphology, its proximity to the Galactic plane b similar to 10 degrees has imposed significant observational challenges. We present a high-resolution weak-lensing study of the cluster with Subaru/Suprime Cam and Hubble Space Telescope imaging data. Our mass reconstruction reveals that the cluster is composed of complicated dark matter substructures closely tracing the galaxy distribution, in contrast, however, with the relatively simple binary X-ray morphology. Nevertheless, we find that the cluster mass is still dominated by the two most massive clumps aligned north-south with a similar to 3: 1 mass ratio (M-200 = 6.29(-1.62)(+2.24) x 10(14) M-circle dot and 1.98(-0.74)(+1.24) x 10(14) M-circle dot for the northern and southern clumps, respectively). The southern mass peak is similar to 2' offset toward the south with respect to the corresponding X-ray peak, which has a 'bullet'-like morphology pointing south. Comparison of the current weak-lensing result with the X-ray, galaxy, and radio. relic suggests that perhaps the dominant mechanism responsible for the observed relic may be a highspeed collision of the two most massive subclusters, although the peculiarity of the morphology necessitates involvement of additional subclusters. Careful numerical simulations should follow in order to obtain more complete understanding of the merger scenario utilizing all existing observations.</P>
Golovich, Nathan,Weeren, Reinout J. van,Dawson, William A.,Jee, M. James,Wittman, David American Astronomical Society 2017 The Astrophysical journal Vol.838 No.2
<P>We present and analyze a rich data set including Subaru/SuprimeCam, HST/Advanced Camera for Surveys and Wide Field Camera 3, Keck/DEIMOS, Chandra/ACIS-I, and JVLA/C and D array for the merging cluster of galaxies ZwCl 0008.8+ 5215. With a joint Subaru+ HST weak gravitational lensing analysis, we identify two dominant subclusters and estimate the masses to be M-200 = 5.8(-1.8)(+2.8) x 10(14) M-circle dot. We estimate the projected separation between the two subclusters to be 924(-206)(+243) kpc. We perform a clustering analysis of spectroscopically confirmed cluster member galaxies and estimate the line-of-sight velocity difference between the two subclusters to be 92 +/- 164 km s(-1). We further motivate, discuss, and analyze the merger scenario through an analysis of the 42 ks of Chandra/ACIS-I and JVLA/C and D array polarization data. The X-ray surface brightness profile reveals a merging gas-core reminiscent of the Bullet Cluster. The global X-ray luminosity in the 0.5-7.0 keV band is 1.7. +/- 0.1 x 10(44) erg s(-1) and the global X-ray temperature is 4.90 +/- 0.13 keV. The radio relics are polarized up to 40%,. and along with the masses, velocities, and positions of the two subclusters, we input these quantities into a Monte Carlo dynamical analysis and estimate the merger velocity at pericenter to be 1800(-300)(+400) km s(-1). This is a lower-mass version of the Bullet Cluster and therefore may prove useful in testing alternative models of dark matter (DM). We do not find significant offsets between DM and galaxies, but the uncertainties are large with the current lensing data. Furthermore, in the east, the BCG is offset from other luminous cluster galaxies, which poses a puzzle for defining DM-galaxy offsets.</P>
Finner, Kyle,Jee, M. James,Golovich, Nathan,Wittman, David,Dawson, William,Gruen, Daniel,Koekemoer, Anton M.,Lemaux, Brian C.,Seitz, Stella American Astronomical Society 2017 The Astrophysical journal Vol.851 No.1
<P>The second most significant detection of the Planck Sunyaev-Zel'dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is located similar to 400 kpc NW of the X-ray peak and the other similar to 2.8 Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. We present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass M-200c = 1.59(-0.22)(+0.25) x 10(15) h(70)(-1) M-circle dot dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass M-200c = 1.16(-0.13)(+0.15) x 10(14) h(70)(-1) M-circle dot located similar to 400 kpc to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected similar to 2 Mpc to the SE of the X-ray peak with mass M-200c =1.68(-0.20)(+0.22) x 10(14) h(70)(-1) M-circle dot. This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, M-200c = 1.87(-0.22)(+0.24) x 10(14) h(70)(-1) M-circle dot, is NW of the X-ray peak and beyond the NW radio relic.</P>
Inhibition of the prostaglandin-degrading enzyme 15-PGDH potentiates tissue regeneration
Zhang, Yongyou,Desai, Amar,Yang, Sung Yeun,Bae, Ki Beom,Antczak, Monika I.,Fink, Stephen P.,Tiwari, Shruti,Willis, Joseph E.,Williams, Noelle S.,Dawson, Dawn M.,Wald, David,Chen, Wei-Dong,Wang, Zhengh American Association for the Advancement of Scienc 2015 Science Vol.348 No.6240
<P><B>A shot in the arm for damaged tissue</B></P><P>Tissue damage can be caused by injury, disease, and even certain medical treatments. There is great interest in identifying drugs that accelerate tissue regeneration and recovery, especially drugs that might benefit multiple organ systems. Zhang <I>et al.</I> describe a compound with this desired activity, at least in mice (see the Perspective by FitzGerald). SW033291 promotes recovery of the hematopoietic system after bone marrow transplantation, prevents the development of ulcerative colitis in the intestine, and accelerates liver regeneration after hepatic surgery. It acts by inhibiting an enzyme that degrades prostaglandins, lipid signaling molecules that have been implicated in tissue stem cell maintenance.</P><P><I>Science</I>, this issue 10.1126/science.aaa2340; see also p. 1208</P><P>Agents that promote tissue regeneration could be beneficial in a variety of clinical settings, such as stimulating recovery of the hematopoietic system after bone marrow transplantation. Prostaglandin PGE2, a lipid signaling molecule that supports expansion of several types of tissue stem cells, is a candidate therapeutic target for promoting tissue regeneration in vivo. Here, we show that inhibition of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a prostaglandin-degrading enzyme, potentiates tissue regeneration in multiple organs in mice. In a chemical screen, we identify a small-molecule inhibitor of 15-PGDH (SW033291) that increases prostaglandin PGE2 levels in bone marrow and other tissues. SW033291 accelerates hematopoietic recovery in mice receiving a bone marrow transplant. The same compound also promotes tissue regeneration in mouse models of colon and liver injury. Tissues from 15-PGDH knockout mice demonstrate similar increased regenerative capacity. Thus, 15-PGDH inhibition may be a valuable therapeutic strategy for tissue regeneration in diverse clinical contexts.</P>