Distances and peculiar velocities of spiral galaxies in the 2MFGC and SFI++ samples

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 Astrophysic

Catalog of Isolated Galaxies Selected from the 2MASS Survey

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 figure

HI Observations of Flat Galaxies

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 figure

Bulk Motions of Spiral Galaxies in the z = 0.03 Volume

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 figure

Peculiar Velocities of 3000 Spiral Galaxies from the 2MFGC Catalog

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

The Bulk Motion of Flat Edge-On Galaxies Based on 2MASS Photometry

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 15.05.200