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Date and Time of the Query: 2019-05-27 T04:03:47 PDT
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Notes for object NGC 1275 Cluster

6 note(s) found in NED.


1. 2010A&A...511A..15L
Re:ABELL 0426
Churazov et al. (2003) presented XMM-Newton data in which a spiral-like
structure was detected in temperature and surface brightness maps. These authors
concluded that this feature is possibly a contact discontinuity separating the
main cluster gas from the gas of the infalling subcluster. A chain of galaxies
is also associated with this region, probably tracing the filament along which
the merger started.
Since it has a strong central radio galaxy, NGC 1275, Boehringer et al.
(1993) argued that the thermal plasma was displaced by the inner parts of the
radio lobe. Fabian et al. (2002) examined in detail the interaction between the
radio source 3C84 and the surrounding medium, arguing that the inner lobes are
currently expanding subsonically.
From our results, one can see that this cluster is one with the most
prominent spiral-arm patterns in both temperature and substructure maps. The
substructure found here is almost identical to that detected by Churazov et al.
(2003, see their Fig. 7).

2. 2008ApJ...687..899R
Re:PERSEUS CLUSTER
Perseus.-The Perseus CDG (NGC 1275) is well known for its blue, emission-line
filaments, dust lanes, and the foreground high-velocity system, all of which
were masked before analysis. Significant star formation was detected by McNamara
& O'Connell (1989), Romanishin (1987), and Smith et al. (1992).

3. 2006A&A...453..447E
Re:NGC 1275 CLUSTER
Perseus cluster
We take the central electron density, temperature and the cool core radius from
Churazov et al. (2003) and the cluster X-ray luminosity from David et al.
(1993).
The Perseus cluster cool core exhibits diffuse radio emission, a radio
mini-halo. One can apply the classical minimum-energy arguments to the radio
halo data to search for the minimum of the sum of the magnetic and relativistic
particle energy densities necessary to reproduce the radio synchrotron emission,
and assume a constant proton to electron ratio k_p_. Pfrommer & Ensslin
(2004b) report a classical minimum field strength of 7.2_-0.4_^+4.5^ microG
(assuming k_p_ = 1), where the confidence interval is given by the
requirement that the energy density should be within one e-fold from the
minimum. Pfrommer & Ensslin (2004b) also develop and apply the hadronic
minimum-energy criteria to the Perseus mini-halo. This criterion assumes that
the relativistic electrons are injected by hadronic interactions of a
relativistic proton population, which usually dominates the relativistic energy
budget. No proton-to-electron factor k_pi_ has to be assumed in this case,
since the physics of the hadronic interaction determines this ratio. Applied to
the Perseus radio halo, a very similar central field strength of
8.8_-5.4^+13.8^ microG was found. Our cool core model predicts a field
strength of 7-13 microG, which is in agreement with these findings. A
significant lower central field value of about 1-3 microG was reported by
Sanders et al. (2005), based on an Inverse Compton interpretation of a hard
photon component in the X-ray spectra of the cool core region. If the hard
photons flux is due to another physical mechanism, the derived value will become
a lower limit. If the Inverse Compton nature of the flux could be verified, this
will be a very good field estimate in the case of a non-intermittent field
distribution. If there is significant magnetic intermittency, spatially
inhomogeneous electron cooling can produce an anti-correlation between fields
and relativistic electrons, which can easily lead to Inverse Compton based
magnetic field estimates lower by a factor of two (Ensslin 2004; Ensslin et al.
1999).
As stated before, Fabian et al. (2003b) argued for a large-scale viscosity in
the Perseus cluster cool core of at least 4 x 10^27^ cm^2^/s, which
is in good agreement with the 1.6 x 10^28^ cm^2^/s predicted in our
1-d scenario.

4. 2006A&A...450....9F
Re:ABELL 0426
A426 - The substructures are located in the field of the cluster at the all
scales.

5. 2004ApJ...608..166N
Re:PERSEUS CLUSTER
Perseus. Perseus hosts a well-known AGN, NGC 1275, in the center. HEAO I
observations revealed a nonthermal component in the Perseus data at the
20-50 keV band (Primini et al. 1981). The excess was modeled with a
power-law model whose best-fit photon index {alpha}_ph_ is 1.9 +- 0.3 at
90% confidence. They also report that the source exhibits no significant
variations above 25 keV in a timescale of 4 yr. PDS data are of high
enough quality to perform a two-component fit if we fix the photon index
(1.9) and MEKAL abundance (0.3). The resulting temperature, 6.3 +- 0.4
keV, is identical to the Ginga value (Allen et al. 1992). The power-law
component has a 25-40 keV luminosity of 1.8 +- 0.5 x 10^43^ ergs s^-1^,
4 times smaller than The HEAO I value, implying variability on a timescale
of 20 yr.
Because of the high brightness of cluster thermal emission in the
center, compared with that of NGC 1275, the central 2" MECS data do not
provide decent constraints on the internal NH or the power-law slope of
the AGN. However, modeling the central MECS data with MEKAL plus the
above power-law component reveals that the power-law model given by the
PDS data contributes only a few percent of the total emission. This
component modifies the total model only slightly, and the fit is
acceptable. If left free, the allowed upper limit for the normalization
of the power-law component is 3 times as high as the best value given by
PDS data. Thus, the data are consistent with all of the nonthermal
emission coming from NGC 1275. We thus reject Perseus from further
analysis.

6. 1997ApJ...482...41G
Re:ABELL 0426
This is an initially extended field. The main cluster (MS) shows an
irregular (elongated) shape and a regular velocity distribution. There is
a strong clustering (C) in the central region. The C structure appears
rather dynamically perturbed (i.e., with a high dispersion), although its
mean velocity well agrees with that of the cluster. Indeed, it has been
recently claimed that this cluster does not appear to be in a complete
relaxed state. In particular, Mohr, Fabricant, & Geller (1993) found
substructures in the core. Also, Slezak et al. (1994) found a double peak
in the core by analyzing X-ray data: however, the region they analyzed is
smaller than our minimum scale analyzed. This cluster is well known for
showing a {beta}-problem ({beta} =1.78_-0.34_^+0.48^ in Edge & Stewart
1991b). The {sigma} is now in acceptable agreement with the estimate of
T({beta} = 1.25_-0.22_^+0.24^). Other observational evidence for reducing
the value of {sigma} comes also from Fadda et al. (1996; {beta} = 1.01_-
0.16_^+0.24^). The strong increase in the VDP toward the cluster center
suggests the presence of galaxies with radial orbits in the external
cluster region, as already suggested by, e.g., Solanes & Salvador-Sole
(1990). The acceptable agreement between {sigma} and T suggests that
these galaxies, although recently infalled into the cluster, are already
roughly virialized within the cluster potential.


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