The Central Star Cluster

2020 ◽  
pp. 86-113
Keyword(s):  
Central Star ◽  
Star Cluster

scholarly journals Dense gas formation triggered by spiral density wave in M31

2006 ◽  
Vol 2 (S237) ◽  
pp. 368-372
Author(s):  
T. Tosaki ◽  
Y. Shioya ◽  
N. Kuno ◽  
K. Nakanishi ◽  
T. Hasegawa ◽  
...  
Keyword(s):  
Rotational Velocity ◽  
Density Wave ◽  
Central Star ◽  
High Ratio ◽  
Star Cluster ◽  
Radio Continuum ◽  
Dense Gas ◽  
Hii Region ◽  
Gas Formation ◽  
Spiral Density Wave

AbstractWe present the high-resolution 12CO(J = 1 − 0), 13CO(J = 1 − 0) and 12CO(J = 3 − 2) maps toward a GMA located on the southern arm region of M31 using Nobeyama 45 m and ASTE 10 m telescopes. The GMA consists of two velocity-components, i.e., red and blue. The blue component shows a strong and narrow peak, whereas the red one shows a weak and broad profile. The red component has a lower 12CO(J = 1 − 0)/13CO(J = 1 − 0) ratio (~ 5) than that of the blue one (~ 16), indicating that the red component is denser than the blue one. The red component could be the decelerated gas if we consider the galactic rotational velocity in this region. We suggest that the red component is “post shock” dense gas decelerated due to a spiral density wave. This could be observational evidence of dense molecular gas formation due to galactic shock by spiral density waves.We also present results from on-going observations toward NGC 604, which is the supergiant HII region of M33, using Nobeyama 45 m and ASTE 10 m telescopes. The ratio of 12CO(J = 3 − 2) to 12CO(J = 1 − 0) ranges from 0.3 to 1.2 in NGC 604. The 12CO(J = 1 − 0) map shows the clumpy structure while 12CO(J = 3 − 2) shows a strong peak near to the central star cluster of NGC 604. The high ratio gas is distributed on the arc-like or shell-like structure along with Hα emission and HII region detected by radio continuum. These suggest that the dense gas formation and second generation star formation occur in the surrounding gas compressed by the stellar wind and/or supernova in central star cluster.

scholarly journals The effect of gaseous accretion disk on dynamics of the stellar cluster in AGN

2014 ◽  
Vol 10 (S312) ◽  
pp. 113-117
Author(s):  
Bekdaulet Shukirgaliyev
Keyword(s):  
Black Hole ◽  
Phase Space ◽  
Accretion Disk ◽  
Compact Star ◽  
Central Star ◽  
Star Cluster ◽  
Space Distribution ◽  
Dynamical Interaction ◽  
Stellar Cluster ◽  
Supermassive Black Hole

AbstractThere is a supermassive black hole, a gaseous accretion disk and compact star cluster in the center of active galactic nuclei, as known today. So the activity of AGN can be represented as the result of interaction of these three subsystems. In this work we investigate the dynamical interaction of a central star cluster surrounding a supermassive black hole and a central accretion disk. The dissipative force acting on stars in the disk leads to an asymmetry in the phase space distribution of the central star cluster due to the rotating accretion disk. In our work we present some results of Stardisk model, where we see some changes in density and phase space of central star cluster due to influence of rotating gaseous accretion disk.

Continuing formation of the central star cluster in M87

Nature ◽  
1984 ◽  
Vol 307 (5949) ◽  
pp. 343-343 ◽  
Author(s):  
A. C. Fabian ◽  
H. Itoh ◽  
G. C. Stewart ◽  
C. R. Canizares ◽  
P. E. J. Nulsen
Keyword(s):  
Central Star ◽  
Star Cluster

The Central Star Cluster of the Star-forming Dwarf Galaxy NGC 5253

1996 ◽  
Vol 457 ◽  
pp. 610 ◽  
Author(s):  
S. C. Beck ◽  
J. L. Turner ◽  
P. T. P. Ho ◽  
J. H. Lacy ◽  
D. M. Kelly
Keyword(s):  
Dwarf Galaxy ◽  
Central Star ◽  
Star Cluster ◽  
Star Forming

scholarly journals An accreting black hole in the nucleus of the bulgeless galaxy NGC 1042

2007 ◽  
Vol 3 (S245) ◽  
pp. 259-260
Author(s):  
Joseph C. Shields ◽  
Carl Jakob Walcher ◽  
Torsten Böker ◽  
Luis C. Ho ◽  
Hans-Walter Rix ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Compact Star ◽  
Star Clusters ◽  
Central Star ◽  
Supermassive Black Holes ◽  
Star Cluster ◽  
Intermediate Mass

AbstractCompact star clusters are commonly found in the centers of galaxies and may foster formation of intermediate-mass “seed” black holes that facilitate the growth of supermassive black holes in galaxy nuclei. Such star clusters can be studied with minimal background starlight contamination in bulgeless galaxies. We present new results that point to the presence of an accreting black hole associated with the central star cluster in the Sd galaxy NGC 1042, and discuss implications for the bulge-black hole connection.

scholarly journals The Evolution of Starburst Galaxies to Active Galactic Nuclei

1989 ◽  
Vol 134 ◽  
pp. 65-68
Author(s):  
Nick Scoville ◽  
Colin Norman
Keyword(s):  
Average Rate ◽  
Galactic Nuclei ◽  
Central Star ◽  
Star Cluster ◽  
Interstellar Gas ◽  
Massive Black Hole ◽  
Central Mass ◽  
Ccd Imaging ◽  
Giant Stars ◽  
Red Giant

Recent observations of luminous IRAS galaxies (LIR > 1011 L⊙) have revealed that virtually all are extremely rich in molecular gas with H2 abundances 5–20 times that of the Milky Way, and deep CCD imaging indicates that most are recent galactic mergers. Interferometric observations at millimeter wavelengths for five of these galaxies demonstrate that approximately half of the interstellar matter is contained in the central kpc. This gas concentration can result in the formation of a massive central star cluster. The deep potential of the central star cluster and the high density of interstellar gas ensure that virtually all of the gas lost during late stellar evolution sinks to the center of the cluster, building up a central, massive black hole. For a coeval star cluster of 4×109 M⊙, a central mass of approximately 1.5×109 M⊙ will accumulate within approximately 108 years and accretion at an average rate of 7 M⊙ yr−1 over this time will result in a mean accretion luminosity of 1013 L⊙. This luminosity, radiated at X-ray and uv wavelengths from the inner accretion disk ionizes the mass loss envelopes of the surrounding red giant stars providing an origin for the broad emission line regions of QSO's. The large linewidths would then be due to orbital motion in the massive central star cluster.

A New Look at Old Temples

2018 ◽  
Vol 4 (1) ◽  
pp. 52-81 ◽  
Author(s):  
Melanie Sticker-Jantscheff
Keyword(s):  
Cultural Transformation ◽  
Star Cluster ◽  
Agricultural Work ◽  
Cosmological Beliefs ◽  
Surrounding Landscape ◽  
New Look

Among the most interesting features of the provincial Roman veteran colony of Augusta Raurica (present-day Switzerland) are its sanctuaries, which were constructed during a period of profound cultural transformation. The current study examines the temples within their surrounding landscape and skyscape, to explore the possibility that their locations and orientations may bear testimony to the cosmological beliefs of the colony's inhabitants. The findings suggest that alignments with the star cluster of the Pleiades and the constellation Orion constituted a connective element between earth and sky and were used by the Gallo-Roman elites to reconcile agricultural work and seasonal festivities with new socio-political and religious requirements.

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