Date and Time of the Query: 2019-06-25 T20:55:07 PDT
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Notes for object ABELL 2151

5 note(s) found in NED.

1. 2006A&A...450....9F
Re:ABELL 2151
A2151 - This is a bimodal cluster.

2. 2002ApJ...576..688B
Hercules .-The Hercules Cluster of galaxies (also known as A2151) has
faint X-ray emission. It shows two peaks of the X-ray intensity (see
Bird et al. 1995; Huang & Sarazin 1996), which we investigated
separately in Figure 2. There is only marginal evidence of soft excess
emission in the brightest of the two peaks (labeled "R "in Table 3).

3. 1999MNRAS.306..857C
Re:ABELL 2151
This cluster is resolved into two components by the RASS because of
its low redshift. We list here the dominant galaxy in A2151a, which
produces 93 per cent of the combined luminosity of the system.

4. 1997ApJ...482...41G
Re:ABELL 2151
This is a highly structured cluster, despite an apparently regular
velocity distribution of the main field. We notice a significant central
structure C ({DELTA}V ~ -700 km s^-1^), an extended subsystem S1 at the
north, and a close background quintet S2 at the east. These three
subsystems, very distant from each other, concern about 50% of the total
population of the cluster. These results are consistent with E94. Bird,
Davis, & Beers (1995) find that X-ray and optical distributions are not
very similar. We confirm this result: in particular, our central C is not
centered on the X-ray cluster center. This fact and the large velocity of
C with respect to that of the whole cluster suggest that C could be
considered a real substructure rather than a particularly relaxed central
region. This cluster should be regarded as a case of present cluster
merging. Moreover, although the {sigma} of the MS sample is in good
agreement with the T by David et al. (1993), it is higher than the T
values detected by Bird et al. (1995) for the individual clumps.

5. 1961AJ.....66..541B
Re:Hercules Cluster
6. Hercules Cluster
This is a loose irregular cluster containing about 75 bright members and a large
number of faint galaxies. Of the bright members, about 70% are spirals and
irregulars and, there are a number of multiples. From a sample of 15 measured
radial velocities, the total kinetic energy of luminous matter was estimated and
the potential energy was obtained from measures of the separations of the 75
bright objects. Application of the virial theorem then showed that it could be
only satisfied for an average galactic mass of about 10^12^ M_sun_ (Burbidge and
Burbidge 1959d). This fact, together with the irregular shape, lack of
concentration, and proportion of irregular and peculiar spirals, led us to
conclude that the cluster was probably unstable on a time scale of ~2X 10^9^
years. Of course, the presence of a large amount of uncondensed material in a
cluster like this cannot be ruled out; luminous intergalactic matter in the form
of the curious structure IC 1182-84 was discovered in this cluster by
Ambartsumian and Schachbazian (1957). Finally, this area of the sky has a number
of concentrations of galaxies and it is possible that Hercules cluster discussed
here may be part of a large aggregate.

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