http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
CLASH-VLT: Environment-driven evolution of galaxies in the<i>z</i>= 0.209 cluster Abell 209
Annunziatella, M.,Mercurio, A.,Biviano, A.,Girardi, M.,Nonino, M.,Balestra, I.,Rosati, P.,Bartosch Caminha, G.,Brescia, M.,Gobat, R.,Grillo, C.,Lombardi, M.,Sartoris, B.,De Lucia, G.,Demarco, R.,Frye, EDP Sciences 2016 Astronomy and astrophysics Vol.585 No.-
Annunziatella, M.,Bonamigo, M.,Grillo, C.,Mercurio, A.,Rosati, P.,Caminha, G.,Biviano, A.,Girardi, M.,Gobat, R.,Lombardi, M.,Munari, E. American Astronomical Society 2017 The Astrophysical journal Vol.851 No.2
<P>We present a high-resolution dissection of the two-dimensional total mass distribution in the core of the Hubble Frontier Fields galaxy cluster MACS J0416.1-2403, at z = 0.396. We exploit HST/WFC3 near-IR (F160W) imaging, VLT/Multi Unit Spectroscopic Explorer spectroscopy, and Chandra data to separate the stellar, hot gas, and dark-matter mass components in the inner 300 kpc of the cluster. We combine the recent results of our refined strong lensing analysis, which includes the contribution of the intracluster gas, with the modeling of the surface brightness and stellar mass distributions of 193 cluster members, of which 144 are spectroscopically confirmed. We find that, moving from 10 to 300 kpc from the cluster center, the stellar to total mass fraction decreases from 12% to 1% and the hot gas to total mass fraction increases from 3% to 9%, resulting in a baryon fraction of approximatively 10% at the outermost radius. We measure that the stellar component represents similar to 30%, near the cluster center, and 15%, at larger clustercentric distances, of the total mass in the cluster substructures. We subtract the baryonic mass component from the total mass distribution and conclude that within 30 kpc (similar to 3 times the effective radius of the brightest cluster galaxy) from the cluster center the surface mass density profile of the total mass and global (cluster plus substructures) dark-matter are steeper and that of the diffuse (cluster) dark-matter is shallower than an NFW profile. Our current analysis does not point to a significant offset between the cluster stellar and dark-matter components. This detailed and robust reconstruction of the inner dark-matter distribution in a larger sample of galaxy clusters will set a new benchmark for different structure formation scenarios.</P>
Girardi, M.,Mercurio, A.,Balestra, I.,Nonino, M.,Biviano, A.,Grillo, C.,Rosati, P.,Annunziatella, M.,Demarco, R.,Fritz, A.,Gobat, R.,Lemze, D.,Presotto, V.,Scodeggio, M.,Tozzi, P.,Bartosch Caminha, G. EDP Sciences 2015 Astronomy and astrophysics Vol.579 No.-
<P>Aims. In the effort to understand the link between the structure of galaxy clusters and their galaxy populations, we focus on MACSJ1206.20847at z ~ 0.44 and probe its substructure in the projected phase space through the spectrophotometric properties of a large number of galaxies from the CLASHVLT survey. Methods. Our analysis is mainly based on an extensive spectroscopic dataset of 445 member galaxies, mostly acquired with VIMOS at VLT as part of our ESO Large Programme, sampling the cluster out to a radius ~2R<SUB>200</SUB> (4 h<SUB>70</SUB><SUP>−1</SUP>Mpc). We classify 412 galaxies as passive, with strong Hδ absorption (red and blue galaxies), and with emission lines from weak to very strong. A number of tests for substructure detection are applied to analyze the galaxy distribution in the velocity space, in 2D space, and in 3D projected phase-space. Results. Studied in its entirety, the cluster appears as a large-scale relaxed system with a few secondary, minor overdensities in 2D distribution. We detect no velocity gradients or evidence of deviations in local mean velocities. The main feature is the WNW-ESE elongation. The analysis of galaxy populations per spectral class highlights a more complex scenario. The passive galaxies and red strong Hδ galaxies trace the cluster center and the WNWESE elongated structure. The red strong Hδ galaxies also mark a secondary, dense peak ~2h<SUB>70</SUB><SUP>−1</SUP> Mpcat ESE. The emission line galaxies cluster in several loose structures, mostly outside R<SUB>200</SUB>. Two of these structures are also detected through our 3D analysis. The observational scenario agrees with MACS J1206.20847 having WNWESE as the direction of the main cluster accretion, traced by passive galaxies and red strong Hδ galaxies. The red strong Hδ galaxies, interpreted as poststarburst galaxies, date a likely important event 12 Gyr before the epoch of observation. The emission line galaxies trace a secondary, ongoing infall where groups are accreted along several directions.</P>
GASP. I. Gas Stripping Phenomena in Galaxies with MUSE
Poggianti, Bianca M.,Moretti, Alessia,Gullieuszik, Marco,Fritz, Jacopo,Jaffé,, Yara,Bettoni, Daniela,Fasano, Giovanni,Bellhouse, Callum,Hau, George,Vulcani, Benedetta,Biviano, Andrea,Omizzolo, A American Astronomical Society 2017 The Astrophysical journal Vol.844 No.1