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NEARGALCAT - Updated Nearby Galaxy Catalog

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Overview

This table contains an all-sky catalog of 869 nearby galaxies having individual distance estimates within 11 Mpc or corrected radial velocities relative to the Local Group centroid VLG < 600 km s-1. The catalog is a renewed and expanded version of the previous Catalog of Neighboring Galaxies by Karachentsev et al. (2004, AJ, 127, 2031). It collects data on the following galaxy observables: angular diameters, apparent magnitudes in the far-UV, B, and Ks bands, H-alpha and H I fluxes, morphological types, H I-line widths, radial velocities, and distance estimates. In this Local Volume (LV) sample, 108 dwarf galaxies still remain without measured radial velocities. The catalog also lists calculated global galaxy parameters: the linear Holmberg diameters, absolute B magnitudes, surface brightnesses, H I masses, stellar masses estimated via K-band luminosity, H I rotational velocities corrected for galaxy inclination, indicative masses within the Holmberg radius, and three kinds of "tidal index" which quantify the local density environment. In the reference paper, the authors briefly discuss the Hubble flow within the LV and different scaling relations that characterize galaxy structure and global star formation in them. They also trace the behavior of the mean stellar mass density, H I-mass density, and star formation rate density within the volume considered.

Catalog Bibcode

2013AJ....145..101K

References

Updated Nearby Galaxy Catalog
     Karachentsev I.D., Makarov D.I., Kaisina E.I.
    =Astronomical Journal, Volume 145, Issue 4, article id. 101, 22 pp. (2013)
    <2013AJ....145..101K>

Provenance

This table was created by the HEASARC in June 2013 based on electronic versions of Tables 1 and 2 from the reference paper which were obtained form the AJ web site.

Parameters

Name
The name of the galaxy, or its number in well-known catalogs. The authors' LV database (http://www.sao.ru/lv/lvgdb) lists all alternative names/numbers, including the galaxy PGC number in the LEDA Extragalactic Database (Paturel et al. 2003, A&A, 412, 45).

RA
The Right Ascension of the galaxy in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 0.1 seconds of time in the original table.

Dec
The Declination of the galaxy in the selected equinox. This was given in J2000.0 equatorial coordinates to a precision of 1 arcsecond in the original table.

LII
The Galactic Longitude of the galaxy.

BII
The Galactic Latitude of the galaxy.

Major_Axis
The major angular diameter a26 of the galaxy, in arcminutes, which corresponds to the Holmberg isophote (~ 26.5 mag arcsec-2) in the B band. The a26 measurements were performed visually, but photometric profiles of different-type galaxies were used for their calibration based on the data by Bremnes et al. (1998, A&AS, 129, 313; 1999, A&AS, 137, 337; 2000, A&AS, 141, 211) and Makarova et al. (2009, MNRAS, 397, 1672). It should be noted that some dwarf galaxies of extremely low surface brightness (especially those resolved into individual stars) have a central surface brightness fainter than the Holmberg isophote. In these cases, the diameter a26 instead corresponds to the exponential scale h of their brightness profile.

Axial_Ratio
The apparent axial ratio of the galaxy, b_26/a_26, measured at the Holmberg isophote.

Bmag_Gal_Extinction
The Galactic extinction in the B band, in magnitudes, towards the galaxy, according to Schlegel et al. (1998, ApJ, 500,525).

FUV_Mag_Limit
This limit parameter is set to '>' if the corresponding parameter value is a lower limit rather than a measured value.

FUV_Mag
The apparent magnitude of the galaxy in the far ultraviolet, mFUV, (effective wavelength = 1539 Angstroms, FWHM = 269 Angstroms) according to the data from the UV survey performed by the Galaxy Evolution Explorer (GALEX). For 295 galaxies, the asymptotic mFUV magnitudes were taken from Lee et al. (2011, ApJS, 192, 6) and are presented in Table 3 of the reference paper without correction for Galactic extinction. For the other galaxies, the GALEX data on the far-UV (FUV) fluxes and FUV magnitudes were extracted from the NASA Extragalactic Database (NED), summing fluxes from all structural knots within the optical galaxy image.

Bmag
The apparent integral magnitude of the galaxy in the B band, the sources of which are listed in the LV database as well as in Table 3 of the reference paper. If a galaxy lacks a photometric BT magnitude, its apparent magnitude was estimated by eye, comparing with images of other galaxies of similar structure with measured BT. In such cases, as a rule for objects of low surface brightness, a typical BT error estimate amounts to ~0.5 mag.

Halpha_Mag_Limit
This limit parameter is set to '>' if the corresponding parameter value is a lower limit rather than a measured value.

Halpha_Mag
The integral magnitude mHalpha of the galaxy in the H-alpha emission line as seen in the Cousins R band. Following the approach by Fukugita et al. (1995, PASP, 107, 945), the authors determined it to be mHalpha =-2.5*log (FHalpha) - 13.64, where FHalpha is the integral flux in the H-alpha line, in units of erg cm-2 s-1. The main source of the flux data is the H-alpha survey of the LV galaxies performed at the 6-m telescope of SAO RAS (Kaisin & Karachentsev 2006, Afz, 49, 337; 2008, A&A, 479, 603; Karachentsev & Kaisin 2007, AJ, 133, 1833; 2010, AJ, 140, 1241), as well as the survey by Kennicutt et al. (2008, APJS, 178, 247). References to the H-alpha data on individual galaxies are given in Table 3 of the reference paper along with the measurement errors. For many galaxies their H-alpha line images are presented in the authors' LV database (http://www.sao.ru/lv/lvgdb).

Ks_Mag
The apparent magnitude of the galaxy in the near-infrared Ks band. The source of the Ks data is the 2MASS sky survey, supplemented by photometric measurements from Fingerhut et al. (2010, ApJ, 716, 792) and Vaduvescu et al. (2005, AJ, 130, 1593; 2006, AJ, 131, 1318). If accurate photometric Ks magnitudes were lacking, they were estimated from the apparent magnitudes in the optical (B, V, R, I) or near-infrared (J, H) bands, as discussed in Section 3 of the reference paper.

Ks_Mag_Flag
This flag parameter is set to 'C' if the galaxy had only a B magnitude available, and the Ks magnitude was determined by the relation between the average color index <B - K> and the morphological T-type, as discussed in Section 3 of the reference paper.

H1_21_cm_Mag_Limit
This limit parameter is set to '>' if the corresponding parameter value is a lower limit rather than a measured value.

H1_21_cm_Mag
The apparent magnitude m21 of the galaxy in the H I line at 21 cm, where m21 = 17.4 - 2.5 * log F_H I_, where the integral H I flux is expressed in Jy km s-1. References to the data sources for F_ H I_ are listed in Table 3 of the reference paper and in the authors' LV database (http://www.sao.ru/lv/lvgdb).

H1_21_cm_50pc_Width
The H I 21-cm line width W50 of the galaxy, in km s-1, measured at the 50% level of the maximum. The main source of W50 data was LEDA, as well as the HIPASS and ALFALFA surveys. The references for the individual W50 measurements are presented in Table 5 of the reference paper and in the LV database (http://www.sao.ru/lv/lvgdb).

Morph_Type
The morphological T type of the galaxy in the numerical code according to the classification by the RC3 (de Vaucouleurs et al. 1991). It should be noted that about three quarters of objects in the LV are dwarf galaxies, which require a more detailed morphological classification. For example, dwarf spheroidal galaxies and normal ellipticals are usually denoted by the same numerical code T < 0, although their physical properties drastically differ. The classification problem arises as well for the "transient" type dwarf galaxies, T r, which combine the features of spheroidal (Sph) and irregular (Ir) systems. Due to small classification errors, such objects may "jump" from one end of the T scale to the other.

Dwarf_Morph_Type
In order to describe the morphology of dwarf galaxies in more detail, the authors introduce a two-parameter scheme, which takes into account both the surface brightness of a dwarf system (the dwarf_surf_brightness discussed below), and its color (or the presence of emission): Ir, Im, BCD-blue, Tr, dS0em, dEem-mixed; and Sph, dE-red. See Section 3 of the reference paper for more details.

Dwarf_Surf_Brightness
In order to describe the morphology of dwarf galaxies in more detail, the authors introduce a two-parameter scheme, which takes into account both the surface brightness of a dwarf system: H for high, N for normal, L for low, and X for extremely low, and its color (or the presence of emission): the dwarf_morph_type parameter discussed above.

Radial_Velocity
The heliocentric radial velocity Vh of the galaxy, in km s-1. The references for them are given in Table 4of the reference paper. As a rule, the authors selected the value of Vh having the smallest measurement error.

Distance
The distance to the galaxy, in Mpc.

Distance_Method
The method used to obtain the distance to the galaxy (references for the distance estimation are presented in Table 6 of the reference paper):

      TRGB = by the tip of the red giant branch;
       Cep = from the Cepheid luminosity;
      geom = by a geometric determination of the distance;
        SN = from the Supernova luminosity;
       SBF = from galaxy surface brightness fluctuations;
       mem = from galaxy membership in known groups with measured distances of
             other members;
    TF, FP = by the Tully-Fisher relation or by the fundamental plane;
        BS = by luminosity of the brightest stars;
       CMD = by the color magnitude diagram using some prominent features or
             simultaneous distance and stellar population fitting;
        HB = by the horizontal branch;
        RR = from the luminosity of RR Lyrae stars;
      PNLF = by the planetary nebula luminosity function;
     h, h' = by the Hubble velocity-distance relation at H_0 = 73 km/s/Mpc, not
             accounting for (h) or in view of (h') a certain Virgo-centric flow
             model
       txt = One of a small number of dwarf galaxies, which are missing
             the measurements of both optical and HI velocities due to their low
             surface brightness and HI deficiency. The texture of these objects
             indicates their likely proximity, which can be verified by future
             observations with HST.
  

Linear_Diameter
The major linear diameter A26, in kiloparsecs, at the Holmberg isophote of the galaxy, corrected for Galactic extinction and inclination according to Fouque and Paturel (1985, A&A, 150, 192).

Inclination
The inclination of the galaxy i from the face-on position, in degrees, calculated from sin2(i) = [1 - (b/a)2] * [1 - ((b/a)0)2]-1, where the intrinsic axial ratio of galaxy (b/a)0 depends on its morphological type T as given in equation (6) of the reference paper. The authors adopted this expression from Paturel et al. (1997, A&AS, 124, 109) with a correction for the slight difference between their type scale and the LEDA T scale. Therefore, for the Ir, Im, and BCD-type galaxies, the authors assume the intrinsic axial ratio to be (b/a)0 = 0.42 in accordance with the statistics of apparent axial ratios of these galaxies.

H1_Rot_Velocity
The amplitude Vm = W50c/[2 sin(i)] of the rotational velocity of the galaxy, in km/s. This is adjusted for the inclination, where the H I line width, W50c, contains a correction for turbulent motions following the Tully & Fouque (1985, ApJS, 58, 67) scheme with a parameter sigmaz = 10 km/s.

Bmag_Int_Extinction
The internal extinction in the galaxy in the B band according to Verheijen (2001, ApJ, 563, 694), viz.: Ai(B) = [1.54 + 2.54 * (log 2*Vm - 2.5)] * log(a/b), if 2*Vm > 78 km s-1, otherwise Ai(B) = 0. Therefore, dwarf galaxies with Vm < 39 km s-1, gas-poor E, and S0 galaxies without W50 estimates, were considered to be fully transparent systems.

Abs_Bmag
The absolute B-band magnitude of the galaxy, corrected for Galactic and internal extinction.

Bmag_Surface_Brightness
The average surface brightness SBB of the galaxy in the B band within the Holmberg isophote, in mag arcsec-2,, viz.: SB = BcT + 5 * log (a26c) + 8.63, where the apparent magnitude and angular diameter are corrected for extinction and inclination.

Log_Ks_Luminosity
The logarithm of the Ks band luminosity of the galaxy, in solar units, corrected for extinction K - Kc = 0.085 * (AGB + ^AiB), and assuming an absolute magnitude of the Sun in the Ks band of 3.28.

Log_Mass_26
The logarithm of the indicative mass M26 within the Holmberg radius of the galaxy, in solar masses, where M26 = 3.31 * 104 * Vm2 * a26c * D, a26c is the corrected angular diameter, in arcminutes, Vm is in km s-1, and D is in Mpc (Roberts & Haynes 1994, ARAA, 32, 115).

Log_H1_Mass_Limit
This limit parameter is set to '<' if the corresponding parameter value is an upper limit rather than a measured value.

Log_H1_Mass
The logarithm of the neutral Hydrogen mass of the galaxy M_H I_ = 2.356 * 105 * D2 * F_H I_, where M_H I_ is expressed in solar masses, D in Mpc, and F_H I_ in Jy km s-1 (Roberts & Haynes 1994, ARAA, 32, 115).

LG_Radial_Velocity
The radial velocity, in km s-1, of the galaxy relative to the Local Group centroid with apex parameters (Karachentsev & Makarov 1996, AJ, 111, 794) adopted from NED and calculated from the heliocentric radial velocity as specified in equation (11) of the reference paper.

Tidal_Index_1
The tidal index Theta1 determined as discussed in Section 8 of the reference paper via the distance and mass of the nearest significant neighbor. Positive values of Theta1 indicate the membership in groups, while negative values correspond to isolated galaxies.

Neighbor_Galaxy_Name
The name of the "main disturber" (MD), i.e., the neighboring galaxy producing the maximal tidal influence on the particular galaxy. In fact, the set of objects in this table with the same MD and Theta1 > 0 corresponds to a definition of the physical group of the galaxies.

Tidal_Index_2
Another tidal index (or density contrast), Theta5, determined by the five most important neighbors as discussed in Section 8 of the reference paper. Unlike Theta1, the index Theta5 seems to be a more robust feature of the galaxy environment.

Log_Ks_Lum_Density
The logarithm of the K-band luminosity density within 1 Mpc around the galaxy, taken in units of the mean global LK density (4.28 * 108 LSun Mpc-3) derived from the Two Micron All Sky Survey (2MASS) by Jones et al. (2006, MNRAS, 369, 25), as discussed in more detail in Section 8 of the reference paper.

Class
The HEASARC Browse object classification of the galaxy based on the value of the morphological T type (the morph_type parameter) of the galaxy.


Contact Person

Questions regarding the NEARGALCAT database table can be addressed to the HEASARC User Hotline.

Page Author: Browse Software Development Team
Last Modified: 6-Jun-2013