Search

We conducted a continuous survey of infrared and visual images of 18020 2MFGC galaxies which were selected on an automatic basis from 1.64 mln extended objects of the 2MASS XSC catalog based on the ratio of the infrared axes a/b>=3. This work aims to exclude "false" objects from the list of flat galaxies. Having observed more than 80 thousand images in different filters, we were able to detect 1512 such objects (8.4% of the total number). We found 23 galaxies duplicated in 2MASS, which have two 2MFGC numbers correspondingly, and three flat galaxies which are not included in other catalogs and are located close to three "false" galaxies. Galaxies with magnitudes fainter than K_s =13 mag compose the main part of the excluded objects. They show small angular sizes, low surface brightnesses and concentration ratios. The results of the work in the form of the 2MFGC table with notes are given in the astronomical databases VizieR, NED, HyperLeda., Comment: 10 pages, 2 tables, 7 figures

We search for isolated galaxies based on the automatic identification of isolated sources from the Two Micron All-Sky Survey (2MASS) followed by a visual inspection of their surroundings. We use the modified Karachentseva criterion to compile a catalog of 3227 isolated galaxies (2MIG), which contains 6% of 2MASS Extended Sources Catalog (or 2MASX) sources brighter than Ks = 12 mag with angular diameters a_K > 30 arcsec. The catalog covers the entire sky and has an effective depth of z = 0.02. The 2493 very isolated objects of the catalog, which we include into the 2MVIG catalog, can be used as a reference sample to investigate the effects of the environment on the structure and evolution of galaxies located in regions with extremely low density of matter., Comment: 19 pages, 13 figures

We undertook searches for isolated galaxies based on automatic selection of infrared sources from the Two Micron All-Sky Survey (2MASS) followed by a visual inspection of their surrounding. Using a modified criterion by Karachentseva (1973), we compiled a catalog of 3227 isolated galaxies (2MIG) containing 6% of 2MASS Extended Sources (2MASX) brighter than $K_s = 12^m$ with angular diameters $a_K \geq 30\arcsec$. The most isolated 2493 galaxies among them enter in the 2MASS Very Isolated Galaxy Catalog, 2MVIG. Being situated in the regions of extremely low mass density, the 2MVIG galaxies can serve as a reference sample for investigation the influence of environment on structure and evolution of galaxies., Comment: 4 pages, 4 figures, Galaxies in Isolation Conference

We compare infrared Tully-Fisher (TF) distances and peculiar velocities derived for spiral galaxies from the two largest datasets: the 2MASS selected Flat Galaxy Catalog, 2MFGC [19, 20] and the Arecibo General Catalog with I-band photometry, SFI++ [30,7]. These samples contain peculiar velocities for ~3000 and ~4000 objects, respectively. Based on a sub-sample of ~1000 common deeply inclined galaxies, we reach the following conclusions. Irrespective to high (SFI++) or low (2MFGC) quality of the used photometric data, about 10% of the galaxies in both samples deviate considerably from the main body of the TF relation. After their deletion, the standard TF scatters drops to 0.47^m (2MFGC) and 0.40^m (SFI++). The TF distances, derived from two the samples, demonstrate a high degree of mutual agreement with a correlation coefficient \ro=+0.95 and \sigma(H_0r)=837 km/s. Peculiar velocities of the galaxies are also correlated with \ro=0.56-0.59 and \sigma(V_pec)=610 km/s. We find that the bulk motion of the 2MFGC and SFI++ galaxies on a typical scale of H_0r~5700 km/s can be represented by a dipole solution with the amplitude V=297+/-23 km/s directed towards l=292+/-4 degr., b=-12+/-3 degr., being only slightly sensitive to different modifications of the TF relaton., Comment: 19 pages, 6 figures. Accepted for publication in Astrophysics

We present a first entire-sky catalog of isolated galaxies obtained via systematic automated and visual inspections of extended sources from the Two Micron All-Sky Survey (2MASS). Based on the Karachentseva's (1973) isolation criteria, we have extracted a sample of 2100 2MIG galaxies consisting a 4% fraction among galaxies brighter than K = 12m. Being the objects with probably no major perturbations in some last billion years, the 2MIG galaxies may be considered as a reference sample to study environment effects in galaxy structure and evolution. The 2MIG catalog may also be useful to explore the existence of dark galaxy population within a volume of z=0.02., Comment: 4 pages, 2 figures, from Proceedings of the conference "Problems of Practical Cosmology", St.Petersburg, Russia, 23-29 June 2008

The 2MFGC catalog we have used contains 18020 galaxies selected from the extended objects in the 2MASS infrared sky survey as having apparent ratios of the axes b/a<0.3. Most of them are spiral galaxies of later morphological types whose disks are seen almost edge-on. The individual distances to the 2724 2MFGC galaxies with known rotation velocities and radial velocities are determined using a multiparameter infrared Tully-Fisher relation. A list of the distances and peculiar velocities of these galaxies is presented. The collective motion of the 2MFGC galaxies relative to the cosmic microwave background is characterized by a velocity V = 199 +- 37 km/s in the direction l = 304o +- 11o, b = -8o +- 8o. Our list is currently the most representative and uniform sample for analyzing non-Hubble motions of galaxies on a scale of ~100 Mpc., Comment: 12 pages, 5 figures, 1 table (here we present the beginning of the table as an illustration). Astrophysics, Vol. 49, No. 4, 2006. Original article submitted June 13, 2006. Translated from Astrofizika, Vol. 49, No. 4, pp. 527-540 (November 2006)

We analyze the peculiar velocity field for 2400 flat spiral galaxies selected from an infrared sky survey (2MFGC). The distances to the galaxies have been determined from the Tully-Fisher relation in the photometric J band with a dispersion of 0.45 mag. The bulk motion of this sample relative to the cosmic microwave background (3K) frame has an amplitude of 199+/-37 km/s in the direction l = 290 +/- 11, b = +1 +/- 9 degree. The amplitude of the dipole motion tends to decrease with distance in accordance with the expected convergence of bulk flows in the 3K frame. We believe that external massive attractors similar to the Shapley cluster concentration are responsible for \~60% of the local flow velocity in the z = 0.03 volume., Comment: 15 pages, 6 figures

We present the HI observations of 94 flat spiral galaxies from RFGC (the Revised Flat Galaxy Catalog) and 14 galaxies from 2MFGC (the 2MASS selected Flat Galaxy Catalog) performed with the 100-m radio telescope in Effelsberg (Germany). HI fluxes, heliocentric radial velocities, and HI line widths are given for 65 detected galaxies. We present a mosaic of HI profiles. We calculated some of the global parameters of the galaxies and analyzed the linear correlations between them. The ratios of the total (indicative) masses of the galaxies to their luminosities lie within the range 0.4 with a mean of 3.8 ($M_{\sun}/L_{\sun}$), and the mean mass fraction of neutral hydrogen is 13%. Upper limits are given for the radio fluxes from 43 undetected galaxies., Comment: 24 pages, 7 figures

An all-sky catalog of 18020 disc-like galaxies is presented. The galaxies are selected from the Extended Source Catalog of the Two Micron All-Sky Survey (XSC 2MASS) basing on their 2MASS axial ratio a/b >= 3. The Catalog contains data on magnitudes of a galaxy in the J, H, K_s bands, its axial ratio, positional angle, index of luminosity concentration, as well as identification of the galaxy with the LEDA and the NED databases. Unlike the available optical catalogs, the new 2MFGC catalog seems to be more suitable to study cosmic streaming on a scale of z <= 0.1. The dipole moment of distribution of the bright (K < 11 mag) 2MFGC objects (l = 227 degr, b = 41 degr or SGL = 90 degr, SGB = -43 degr) lies within statistical errors (+/- 15 degr) in the direction of the IRAS dipole and the optical RFGC dipole., Comment: Paper: 21 pages, 15 figures ftp://ftp.sao.ru/pub2/llss/2MFGC/Paper.ps.gz Catalog: 142 pages ftp://ftp.sao.ru/pub2/llss/2MFGC/Catalog.ps.gz

We report the results of applying the 2MASS Tully-Fisher (TF) relations to study the galaxy bulk flows. For 1141 all-sky distributed flat RFGC galaxies we construct J, H, K_s TF relations and find that Kron $J_{fe}$ magnitudes show the smallest dispersion on the TF diagram. For the sample of 971 RFGC galaxies with V_{3K} < 18000 km/s we find a dispersion $\sigma_{TF}=0.42^m$ and an amplitude of bulk flow V= 199 +/-61 km/s, directed towards l=301 degr +/-18 degr, b=-2 degr +/-15 degr. Our determination of low-amplitude coherent flow is in good agreement with a set of recent data derived from EFAR, PSCz, SCI/SCII samples. The resultant two- dimensional smoothed peculiar velocity field traces well the large-scale density variations in the galaxy distributions. The regions of large positive peculiar velocities lie in the direction of the Great Attractor and Shapley concentration. A significant negative peculiar velocity is seen in the direction of Bootes and in the direction of the Local void. A small positive peculiar velocity (100 -- 150 km/s) is seen towards the Pisces-Perseus supercluster, as well as the Hercules - Coma - Corona Borealis supercluster regions., Comment: 10 pages, 5 figures. A&A/2003/3582 accepted 15.05.2003

The spiral edge-on galaxies from the "Revised Flat Galaxy Catalog" (RFGC) are identified with the Extended Source Catalog of the Two Micron All Sky Survey (2MASS). A relative number of the 2MASS detected galaxies is 2996/4236 = 0.71. We consider the statistical properties of the Tully-Fisher relations for the edge-on galaxies in the B, I, J, H, and K_s bands. The slope of derived TF relations increases steadily from 4.9 in the B band to 9.3 in the K one. The effect is mainly due to the internal extinction which is different in dwarf and giant spiral galaxies seen edge-on that leads to the tight correlation between galaxy color and luminosity. The moderate scatter of the RFGC galaxies in the `color-luminosity' diagram, 0.86 mag., provides us with a new "cheap" method of mass measurements of distances to galaxies on the basis of modern photometric sky surveys., Comment: 9 pages, 10 figures, 1 table. Paper is accepted for publication in Jurnal Astronomy and Astrophysics, Tue, 10 Sep 2002, A&A/2002/2893