Visual Survey of 18020 Objects from the 2MFGC Catalog

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 figure

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

Cosmicflows-2: The Data

Cosmicflows-2 is a compilation of distances and peculiar velocities for over 8000 galaxies. Numerically the largest contributions come from the luminosity-linewidth correlation for spirals, the TFR, and the related Fundamental Plane relation for E/S0 systems, but over 1000 distances are contributed by methods that provide more accurate individual distances: Cepheid, Tip of the Red Giant Branch, Surface Brightness Fluctuation, SNIa, and several miscellaneous but accurate procedures. Our collaboration is making important contributions to two of these inputs: Tip of the Red Giant Branch and TFR. A large body of new distance material is presented. In addition, an effort is made to assure that all the contributions, our own and those from the literature, are on the same scale. Overall, the distances are found to be compatible with a Hubble Constant H_0 = 74.4 +-3.0 km/s/Mpc. The great interest going forward with this data set will be with velocity field studies. Cosmicflows-2 is characterized by a great density and high accuracy of distance measures locally, falling to sparse and coarse sampling extending to z=0.1.Comment: To be published in Astronomical Journal. Two extensive tables to be available on-line. Table 1 available at http://edd.ifa.hawaii.edu select catalog `Cosmicflows-2 Distances

The mid-infrared Tully-Fisher relation: Spitzer Surface Photometry

The availability of photometric imaging of several thousand galaxies with the Spitzer Space Telescope enables a mid-infrared calibration of the correlation between luminosity and rotation in spiral galaxies. The most important advantage of the new calibration in the 3.6 micron band, IRAC ch.1, is photometric consistency across the entire sky. Additional advantages are minimal obscuration, observations of flux dominated by old stars, and sensitivity to low surface brightness levels due to favorable backgrounds. Through Spitzer cycle 7 roughly 3000 galaxies had been observed and images of these are available at the Spitzer archive. In cycle 8 a program called Cosmic Flows with Spitzer has been initiated that will increase by 1274 the available sample of spiral galaxies with inclinations greater than 45 degrees from face-on suitable for distance measurements. This paper describes procedures based on the photometry package Archangel that are being employed to analyze both the archival and the new data in a uniform way. We give results for 235 galaxies, our calibrator sample for the Tully-Fisher relation. Galaxy magnitudes are determined with uncertainties held below 0.05 mag for normal spiral systems. A subsequent paper will describe the calibration of the [3.6] luminosity-rotation relation.Comment: Accepted for publication in The Astronomical Journal, 12 pages, 9 figure

The observed infall of galaxies towards the Virgo cluster

We examine the velocity field of galaxies around the Virgo cluster induced by its overdensity. A sample of 1792 galaxies with distances from the Tip of the Red Giant Branch, the Cepheid luminosity, the SNIa luminosity, the surface brightness fluctuation method, and the Tully-Fisher relation has been used to study the velocity-distance relation in the Virgocentric coordinates. Attention was paid to some observational biases affected the Hubble flow around Virgo. We estimate the radius of the zero-velocity surface for the Virgo cluster to be within (5.0 - 7.5) Mpc corresponding to (17 - 26)^\circ at the mean cluster distance of 17.0 Mpc. In the case of spherical symmetry with cosmological parameter \Omega_m=0.24 and the age of the Universe T_0= 13.7 Gyr, it yields the total mass of the Virgo cluster to be within M_T=(2.7 - 8.9) * 10^{14} M_\sun in reasonable agreement with the existing virial mass estimates for the cluster.Comment: 22 pages, 11 figures, 2 tables. Accepted for publication in MNRA

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