Photometric catalogue of Shakhbazian compact groups of galaxies. III.

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.     

Photometric catalogue of Shakhbazian compact groups of galaxies. IV.

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.     

Photometric catalogue of Shakhbazian compact groups of galaxies. I

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.     

Photometric catalogue of Shakhbazian compact groups of galaxies. II

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.     

Catalogue of Shakhbazian compact groups of galaxies. VI.

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.     

Catalogue of Shakhbazian compact groups of galaxies. VIII

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.     

Catalogue of Shakhbazian compact groups of galaxies. IX

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.     

Catalogue of Shakhbazian compact groups of galaxies. VII.

The seventh 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 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 142, 149, 150, 153, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166. For the estimation of the coordinates the Digitized Sky Survey was used.     

Catalogue of Shakhbazian compact groups of galaxies. X

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.     

On the completeness of the lists of Compact Galaxy Groups

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.     

Isolated Shakhbazian compact groups

It is more appropriate to study the dynamics and evolution of compact groups using a sample of isolated compact groups in the nearby vicinity of which there are no accordant redshift galaxies. To look for isolated compact groups we inspected the environment of 78 Shakhbazian compact groups, with known redshifts. We found that 26 of nearby groups with V < 40000 km s⁻¹ are isolated compact groups in the vicinity of which up to a projected distance of 1 Mpc there are no accordant redshift galaxies. For four of them, the redshift of only two members are known, so their being groups is not certain. In the vicinities of eleven distant groups (V > 40000 km s⁻¹) no accordant redshift galaxies are detected as well. The reason for this may be the faintness of galaxies there. These groups may possibly be isolated.     

Photometric observations of nine Shakhbazian compact groups

By observations with the 1.5m telescope at San Pedro Martir (OAN, UNAM, Mexico) the BVR magnitudes are determined for 66 member galaxies in Shakhbazian Compact Galaxy Groups ShCG 40, ShCG 176, ShCG 270, ShCG 278, ShCG 310, and ShCG 342. Three other groups were observed in two or only in one band. Seven galaxies in ShCG 298 were observed in B and R, six galaxies in ShCG 95 were observed in V, and seven galaxies in ShCG 345 were observed in V and R. The distribution of brightness of observed galaxies is determined. Signs of interaction between galaxies are detected in some groups.     

Redshifts of 19 Shakhbazian compact groups of galaxies

By observations at Calar Alto (Spain), La Silla (Chile) and Cananea (Mexico), we measured redshifts of 108 candidate members in 19 Shakhbazian compact galaxy groups ShCG 44, 105, 149, 168, 270, 276, 278, 279, 298, 303, 304, 310, 317, 331, 339, 340, 345, 358, and 359. Redshifts of another ten members were taken from the NED. We found that nine out of 118 candidate member galaxies are stars, and twelve galaxies are not members of the corresponding groups and are projected over them. The group ShCG 168 is the core of a cluster. The groups ShCG 276, ShCG 298, and ShCG 303 are either strongly contaminated by field galaxies with redshift differing not very much from that of the corresponding group, or are the results of a chance projection of field galaxies.     

Spectroscopy and photometry of ShCG 191 – Abell 1097

In the course of investigation of Shakhbazian compact groups we studied the group ShCG 191 which has been identified also as the Abell cluster A1097. By its richness it may be classified as a rich compact group or a poor cluster. We determined redshifts of 14 objects in the area of the cluster and found that two of the supposed members of the group are stars. Redshifts of 12 galaxies show that the system is gravitationally bound. The V and R magnitudes of 23 member galaxies and their morphological types are determined. We present in this paper also the surface brightness contours of member galaxies in the central area of the cluster, the curves of isophotal twisting and the Fourier parameter a₄. It is shown that some galaxies in the cluster are interacting with each other. Physical parameters of the group are close to those of ShCGs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Ursa Major supercluster of galaxies: I. The luminosity function

Catalogs of bright galaxies in the central regions of 11 clusters in the Ursa Major supercluster are presented. Absolute and relative coordinates and total B and R magnitudes are given for each galaxy. Plates taken with the 2-m Tautenburg Observatory telescope and CCD images obtained with the 6-m and 1-m SAO telescopes are used. The luminosity functions (LFs) for galaxies in the cluster nuclei (3 Mpc×3 Mpc) and the composite LF for the supercluster are constructed. The composite LF is well fitted by a Schechter function with $M_B^ * = - 20\mathop .\limits^m 91$ , α=?1.02 and with $M_R^ * = - 22\mathop .\limits^m 39$ , α=?1.06. A comparison with the LFs of field galaxies and of various samples of clusters and superclusters shows that the Ursa Major supercluster have LF parameters characteristic of the field and, thus, differ from those of the Corona Borealis supercluster, which is apparently at a later stage of dynamical evolution.     

Groups of galaxies. IV. Effect of observational selection on the relationship between the characteristics and distance of groups and a comparison with the groups of Geller and Huchra

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. __________ Translated from Astrofizika, Vol. 50, No. 4, pp. 535–546 (November 2007).     

Ten new very low‐mass close binaries resolved in the visible

We present preliminary results from the first part of the LuckyCam late M‐dwarf binarity survey. We survey a sample of 48 nearby (< 40 pc) and red (M5–M9) stars with the novel high angular resolution visible light imaging technique Lucky Imaging, in only 8 hours of 2.5m telescope time. We discover 10 new binaries; although the survey is sensitive to brown dwarf companions none are detected. The orbital radius distribution of the newly discovered binaries broadly matches that of previous detections by other groups, although we do discover one wide binary at ∼40 AU. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

New probable dwarf galaxies in northern groups of the Local Supercluster

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.     

Study of galaxies in the Lynx-Cancer void. IV. Photometric properties

We present the results of a photometric study of 85 objects from the updated sample of galaxies residing in the nearby Lynx-Cancer void. We perform our photometry on u, g, r, and i-band images of the Sloan Digital Sky Survey. We determine model-independent galaxy parameters such as the integrated magnitudes and colors, effective radii and the corresponding surface brightness values, optical radii and Holmberg radii. We analyze the radial surface brightness profiles to determine the central brightness values and scale lengths of the model disks. We analyze the colors of the outer parts of the galaxies and compare them with model evolutionary tracks computed using the PEGASE 2 software package. This allowed us to estimate the time T _SF elapsed since the onset of star formation, which turned out to be on the order of the cosmological time T ₀ for the overwhelming majority of the galaxies studied. However, for 13 galaxies of the sample the time T _SF does not exceed T ₀/2 ～ 7 Gyr, and for 7 of them T _SF ? 3.5 Gyr. The latter are mostly unevolved objects dominated by low-luminosity galaxies with M _B > ?13.2. We use the integrated magnitudes and colors to estimate the stellar masses of the galaxies.We estimate the parameter M(H I)/L _B and the gas mass fractions for void galaxies with known HI-line fluxes. A small subgroup (about 10%) of the gas-richest void galaxies with M(H I)/L _B ? 2.5 has gas mass fractions that reach 94–99%. The outer regions of many of these galaxies show atypically blue colors. To test various statistical differences between void galaxies and galaxies from the samples selected using more general criteria, we compare some of the parameters of void galaxies with similar data for the sample of 195 galaxies from the Equatorial Survey (ES) based on a part of the HIPASS blind HI survey. The compared samples have similar properties in the common luminosity interval ?18.5<M _g < ?13.5. The faintest void galaxies differ appreciably from the ES survey galaxies. However, the ES survey also contains about 7% of the so-called “inchoate” galaxies with highM(H I)/L _B ratios, most of which are located far from massive neighbors and are probably analogs of void galaxies.     

The Fundamental Plane of E Galaxies in Compact Groups

We present a study focusing on the nature of compact groups through the study of their elliptical galaxies. We determine central velocity dispersions (σ_o) 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.