共查询到20条相似文献，搜索用时 187 毫秒
1.
The fourth part of the photometric catalogue of Shakhbazian compact groups of galaxies contains optical and geometrical properties of another 26 groups (Shkh 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 357). As in the previous papers photometric data were obtained from the COSMOS/UKST catalogue of the Southern sky with δ ± +2°30'. The survey of compact galaxy groups by Shakhbazian, Petrosian, Baier, and Tiersch is a basis for studying physical properties of such groups. 相似文献
2.
The third part of the photometric catalogue of Shakhbazian compact groups of galaxies contains optical and geometrical properties of another 24 groups (Shkh 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299, 300, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312). As in the first paper photometric data were obtained from the COSMOS/UKST catalogue of the Southern sky with δ ⩽ +2°30'. The survey of compact galaxy groups by Shakhbazian, Petrosian, Baier, and Tiersch is a basis for studying physical properties of such groups. 相似文献
3.
The sixth part of the catalogue of Shakhbazian compact groups of galaxies contains the positions and references of all the galaxies of the following 48 groups (north of δ > +2°30''): Shkh 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107. For the estimation of the coordinates the Digitized Sky Survey was used. 相似文献
4.
We present the position and references (if available) of all the galaxies of the Shakhbazian survey being the largest survey of compact galaxy groups. For the estimation of the coordinates the Digitized Sky Survey was used. This paper contains the data of 48 Shakhbazian groups north of δ > + 2deg;30' (Shkh 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 25, 26, 28, 29, 31, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56). 相似文献
5.
The tenth part of the catalogue of Shakhbazian groups contains the positions and references of all the galaxies of the following 35 groups (north of δ > +2°30'): Shkh 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 354, 355, 356, 358, 359, 360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377. For the estimation of the coordinates the Digitized Sky Survey was used. 相似文献
6.
D. Stoll H. Tiersch H. Oleak F. Baier H. T. Macgillivray 《Astronomische Nachrichten》1993,314(5):317-360
The second part of the photometric catalogue of Shakhbazian compact groups of galaxies contains optical and geometrical properties of another 24 groups (Shkh 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, 284, 285, 286, 287). As in the first paper photometric data were obtained from the COSMOS/UKST catalogue of the Southern sky with δ ≤ +2°30′. The survey of compact galaxy groups by Shakhbazian, Petrosian, Baier, and Tiersch is a basis for studying dynamical processes in such groups. 相似文献
7.
D. Stoll H. Tiersch H. Oleak F. Baier H. T. Macgillivray 《Astronomische Nachrichten》1993,314(4):225-267
Compact groups of galaxies are fruitful laboratories to study such processes as dynamical friction, tidal interaction, collision, and galaxy mergers. The largest survey of compact galaxy groups is the one of Shakhbazian, Petrosian, Baier, Tiersch. A programme to evaluate photometrical properties of the galaxies in the Shakhbazian groups has been started using the COSMOS/UKST catalogue of the Southern sky with δ ≤ + 2°30′. About a quarter of the Shakhbazian groups lie south of this declination limit. A list of 24 groups (Shkh 21, 24, 27, 30, 32, 33, 35, 81, 82, 83, 140, 141, 143, 144, 145, 146, 147, 148, 151, 152, 154, 261, 262, 263) is our first result. 相似文献
8.
The eighth part of the catalogue of Shakhbazian groups contains the positions and references of all the galaxies of the following 48 groups (north of δ > + 2°30'): Shkh 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 207, 208, 209, 210, 211, 212, 213, 214, 215. For the estimation of the coordinates the Digitized Sky Survey was used. 相似文献
9.
The nineth part of the catalogue of Shakhbazian groups contains the positions and references of all the galaxies of the following 48 groups (north of δ < +2°30'): Shkh 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 253, 254, 255, 256, 257, 258, 259, 260, 328, 338, 339, 340, 340a. For the estimation of the coordinates the Digitized Sky Survey was used. 相似文献
10.
A. P. Mahtessian 《Astrophysics》2007,50(4):440-450
The effect of observational selection on the relationship between the characteristics of groups of galaxies and their distances
is discussed in this paper. For our groups the dependence of the pairwise distance between the members on the distance of
the group is just that. For the groups of Geller and Huchra, on the other hand, the analogous dependence is distorted by the
effect of their selection criteria for groups of galaxies. The average dispersion of the radial velocities of the galaxies
for our groups is less than half that for the groups of Geller and Huchra, while the mass-to-luminosity ratio is smaller,
on the average, by more than an order of magnitude in our case. Geller-Huchra groups with mass-to-luminosity ratios greater
than 1000 are most likely unreal.
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Translated from Astrofizika, Vol. 50, No. 4, pp. 535–546 (November 2007). 相似文献
11.
It is shown that the lists of Shakhbazian Compact Galaxy Groups (SCGGs) are not complete. The number of the detected groups in the strip between b = ±30° and b = ±20° is by four to five times smaller than expected. The most probable reason is that during the search for SCGGs it was hard to distinguish images of compact galaxies from that of stars on the POSS prints in dense areas of the sky at lower galactic latitudes. There is some deficit of the detected groups between 60° and 40° of the north galactic latitudes. The surface density of SCGGs in the southern galactic hemisphere between b = −50° and b = −30° is by about three times less than it is expected. Obviously, the southern sky has not been searched properly. The list of Hickson's groups is complete down to galactic latitude ±30°. However, some excess of HCGs is found in the southern hemisphere, where the surface density of the found groups is by about two times higher than that of in the northern hemisphere. 相似文献
12.
We present a study focusing on the nature of compact groups through the study of their elliptical galaxies. We determine central
velocity dispersions (σo) for 18 bright elliptical galaxies located in the core of Hickson compact groups and a control sample of 12 brightbona fide ellipticals located in the field or very loose groups. Several tests are carried out to avoid systematic effects in σ measurements.
We use these velocity dispersions to compare the position of 11 compact group galaxies in the Fundamental Plane to that of
a large and homogeneous sample of elliptical galaxies (Burstein et al., 1987).We find that little or no significant difference
exists, as far as the Fundamental Plane is concerned, between ellipticals in compact groups and their counterparts in other
environments.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
We find a strong correlation between the effective radius of the largest early-type galaxies in compact groups of galaxies and the velocity dispersion of the groups. The lack of a similar correlation for late type galaxies is supportive of the so called second generation merging scenario which predicts that ellipticals should dominate the internal dynamics of the groups, while late-type galaxies are mainly recent interlopers which are still in an early stage of interaction with the group potential. 相似文献
14.
We have searched for nearby dwarf galaxies in 27 northern groups with characteristic distances 8–15 Mpc based on the Second Palomar Sky Survey prints. In a total area of about 2000 square degrees, we have found 90 low-surface-brightness objects, more than 60% of which are absent from known catalogs and lists. We have classified most of these objects (～80%) as irregular dwarf systems. The first 21-cm line observations of the new objects with the 100-m Effelsberg radio telescope showed that the typical linear diameters (1–2 kpc), internal motions (～30 km s?1), and hydrogen masses (～2 × 107 M ⊙) of the new galaxies correspond to those expected for the dwarf population of nearby groups. 相似文献
15.
The comparison of the spatial distribution of galaxies in the surroundings of the nearest compact and loose groups of galaxies confirms that compact groups are very likely to be part of looser groups and shows that loose groups associated to compact groups tend to have higher spatial density than normal ones. 相似文献
16.
We used a sample of 20 poor groups of galaxies to study the low mass tail of the relationships among the X-ray temperature
T, the X-ray luminosity Lx and the optical velocity dispersion σ. We obtained redshifts for the fainter members of these groups. We find that X-ray
bright groups have more members and higher velocity dispersions on average. Using the fainter group members and MonteCarlo
tests, we define the number of group members required to calculate a robust velocity dispersion. There is a tendency to underestimate
the group velocity dispersion for samples of fewer than∼ 10 members that introduces systematic errors in the slope of the
relationships among Lx, T, and σ. A comparison with the data of Ponman and Mahdavi shows that our improved velocity dispersions provide better constraints
on the relationship between the kinematics of the hot gas and galaxies in these common environments.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Results are presented from a spectral, photometric, and morphological study of two compact groups of compact galaxies (CGCG)
from Shahbazian’s list. The observations were made on the 1.5-m ESO telescope and the 2.6-m telescope at the Byurakan Astrophysical
Observatory (BAO) during 1999–2000. These data are compared with data for the Shahbazian compact group 4. A high spatial density
of galaxies, ranging from 10000 to 100000 galaxies per Mpc3, is observed in all the groups that were studied. The discovery of a Seyfert Sy1 galaxy in the Shahbazian 355 compact group
is especially noteworthy. The direct photographs of the CGCGs that were studied contain no signs of merging or tidal interactions
among the members of these groups. This suggests that the galaxies in these dense systems have a common origin.
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Translated from Astrofizika, Vol. 50, No. 3, pp. 347–353 (August 2007). 相似文献
18.
Compact groups are association of 4-8 galaxies with high spatial densities (Δρ/ρ∼10–20), but low velocity dispersion. Galaxy-galaxy
interactions (e.g. close tidal encounters or mergers) are therefore likely to dominate any environmentally-dependent evolution
of galaxies in these compact, highlocal-density, groups, unlike in the field, where galaxy densities are too low, and in clusters,
where relative velocities are too high. We present here the results from spectroscopic and photometric observations of a new
sample of compact groups in the Southern Sky, selected by an automatic detection algorithm applied to a digitized galaxy database.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
A nearby group of galaxies, centered at the spiral galaxy NGC 972 and conspicuously rich in faint dwarf spheroidal galaxies, has been investigated photometrically on the B and V plates, obtained with the Tautenburg 2m Schmidt telescope. For ten certain and probable group members the equivalent B and V brightness profiles have been extracted. Integrated magnitudes and mean colours of faint group members have been estimated. Typically, the dwarfs show a “subexponential” (i.e. a convex curvature over the linear radius) surface brightness profile and often a central excess. Their equivalent profiles are reasonably well fitted by modified isothermal (King) models. 相似文献
20.
We study morphology and luminosity segregation of galaxies in groups. We analyze the two catalogs of (∼2×400) groups which
have been identified in the Nearby Optical Galaxy sample, by means of hierarchical and percolation `friends-of-friends' methods.
We find that earlier-type (brighter) galaxies are more clustered and lie closer to the group centers, both in position and
in velocity, than later-type (fainter) galaxies. Spatial segregations are stronger than kinematical segregations. These effects
are generally detected at the ≳3-sigma level, with the exception of morphological segregation in velocity, which is the weakest
effect. Our main results are confirmed by the analysis of statistically more reliable groups (with at least five members),
and are strengthened by the detection of segregation in both hierarchical and percolation catalogs. Luminosity segregation
is shown to be independent of morphology segregation. Our conclusions agree with a continuum of segregation properties of
galaxies in systems, from low-mass groups to massive clusters.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献