J/MNRAS/479/4136 Morphological properties of galaxies (Karachentsev+, 2018)
Morphological properties of galaxies in different Local Volume environments.
Karachentsev I.D., Kaisina E.I., Makarov D.I.
<Mon. Not. R. Astron. Soc., 479, 4136-4152 (2018)>
=2018MNRAS.479.4136K 2018MNRAS.479.4136K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby; Galaxies, photometry ; Optical
Keywords: galaxies: dwarf - galaxies: formation - galaxies: star formation
Abstract:
We consider an all-sky sample of 1029 Local Volume (LV) galaxies
situated within a distance of 11 Mpc. Majority of them have precise
distances and estimates of hydrogen mass fraction and star-formation
rate derived from far-ultraviolet or Hα fluxes. To describe an
environment, we attribute two dimensionless values: the density
contrast created by the most significant neighbour and the local
density contrast produced by all neighbours within a separation of
1Mpc. The hydrogen mass fraction exhibits a weak effect of HI
deficiency being the most pronounced for irregular dwarf galaxies. The
specific star formation rate (sSFR) is more sensitive to the
environment than the hydrogen mass fraction. Almost all (99 per cent)
LV galaxies have their sSFRs below -9.4dex (yr-1). We notice that
irregular dwarfs as well as late-type bulgeless galaxies are capable
of reproducing their stellar mass with the observed sSFR over the
cosmic time. Thus, the transformation of gas into stars in dIrs and
spiral discs is rather sluggish unlike that in E, S0, dSph galaxies,
whose star formation history has been stormy and short. The
SFR(Hα)-to-SFR(FUV) scatter ratio increases from Sc, Sd, Sm
galaxies towards BCD, Im, Ir types which favours the idea of bursty
star formations in low-mass galaxies. However, this bursty activity is
caused rather by internal processes than by an external tidal action.
A fraction of quenched E, S0, dSph galaxies increases from ∼5 per
cent in the field up to ∼50 per cent in the densest regions.
Description:
We have considered the influence of an environment on global
properties of galaxies: the neutral hydrogen abundance, star formation
rate, morphological type, and average surface brightness. The sample
used contains 1029 galaxies within the sphere of 11Mpc radius around
the Milky Way. The bulk of this sample, ∼85 per cent, comprises dwarf
galaxies most exposed to external action due to their shallow
potential well.
To characterize an environment, we used two parameters: the density
contrast θ1 provided by the most significant neighbour, and the
local density excess θj within 1-Mpc distance around a galaxy
taken relative to the average cosmic density. Variations in the values
of the parameters θ1 and θj exceed five orders of
magnitude. The hydrogen-to-stellar mass ratio of a galaxy reveals a
weak effect of the HI deficiency in high-density regions being most
noticeable in the case of low-mass irregular dwarfs.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 106 1029 Stellar masses and SFRS of late-type galaxies
in the LV
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- Name Galaxy name in well-known catalogs
27- 28 I2 h RAh Right ascension (J2000)
29- 30 I2 min RAm Right ascension (J2000)
31- 34 F4.1 s RAs Right ascension (J2000)
35 A1 --- DE- Declination sign (J2000)
36- 37 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
40- 41 I2 arcsec DEs Declination (J2000)
44- 45 I2 --- T ? Morphological type in
de Vaucouleurs scale
48- 52 F5.2 Mpc D Distance
55- 59 F5.2 [Msun] logM* ? Log the stellar mass
61 A1 --- l_logMHI Limit flag on hydrogen mass MHI
62- 66 F5.2 [Msun] logMHI ? Log the hydrogen mass
70 A1 --- l_log(SFRFUV) Limit flag on Log SFR from FUV-flux
71- 75 F5.2 [Msun/yr] log(SFRFUV) ? SFR from FUV-flux in (Msun/yr)
80 A1 --- l_log(SFRHa) Limit flag on Log SFR from H-alpha-flux
81- 85 F5.2 [Msun/yr] log(SFRHa) ? SFR from h-alpha-flux in (Msun/yr)
89- 92 F4.1 mag/arcsec+2 SB ? Average B-band surface brightness
95- 99 F5.2 --- theta1 Dimensionless parameters characterizing
the local density contrast
102-106 F5.2 --- thetaj ? Dimensionless parameters
characterizing the local density
contrast
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Acknowledgements:
Elena Kaisina, sskaisin(at)gmail.com
(End) Elena Kaisina [SAO RAS, Russia], Patricia Vannier [CDS] 30-Dec-2021