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NGC 4991


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XMM-Newton observation of the Coma Galaxy cluster. The temperature structure in the central region
We present a temperature map and a temperature profile of the centralpart (r < 20' or 1/4 virial radius) of the Coma cluster. We combined5 overlapping pointings made with XMM/EPIC/MOS and extracted spectra inboxes of 3.5'x3.5'. The temperature distribution around the two centralgalaxies is remarkably homogeneous (r<10'), contrary to previous ASCAresults, suggesting that the core is actually in a relaxed state. Atlarger distance from the cluster center we do see evidence for recentmatter accretion. We confirm the cool area in the direction of NGC 4921,probably due to gas stripped from an infalling group. We findindications of a hot front in the South West, in the direction of NGC4839, probably due to an adiabatic compression. Based on observationsobtained with XMM-Newton, an ESA science mission with instruments andcontributions directly funded by ESA Member States and the USA (NASA).EPIC was developed by the EPIC Consortium led by the PrincipalInvestigator, Dr. M. J. L. Turner. The consortium comprises thefollowing Institutes: University of Leicester, University of Birmingham,(UK); CEA/Saclay, IAS Orsay, CESR Toulouse, (France); IAAP Tuebingen,MPE Garching, (Germany); IFC Milan, ITESRE Bologna, IAUP Palermo, Italy.EPIC is funded by: PPARC, CEA, CNES, DLR and ASI.

A Complete Redshift Survey to the Zwicky Catalog Limit in a 2^h X 15 deg Region around 3C 273
We compile 1113 redshifts (648 new measurements, 465 from theliterature) for Zwicky catalog galaxies in the region (-3.5d <= delta<= 8.5d, 11h5 <= alpha <= 13h5). We include redshifts for 114component objects in 78 Zwicky catalog multiplets. The redshift surveyin this region is 99.5% complete to the Zwicky catalog limit, m_Zw =15.7. It is 99.9% complete to m_Zw = 15.5, the CfA Redshift Survey(CfA2) magnitude limit. The survey region is adjacent to the northernportion of CfA2, overlaps the northernmost slice of the Las CampanasRedshift Survey, includes the southern extent of the Virgo Cluster, andis roughly centered on the QSO 3C 273. As in other portions of theZwicky catalog, bright and faint galaxies trace the same large-scalestructure.

An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.

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Observation and Astrometry data

Constellation:Virgo
Right ascension:13h09m15.10s
Declination:+02°20'51.0"
Aparent dimensions:0.575′ × 0.457′

Catalogs and designations:
Proper Names   (Edit)
NGC 2000.0NGC 4991
HYPERLEDA-IPGC 45604

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