J/MNRAS/499/3399 Long tidal tails in merging galaxies (Ren+, 2020)
Long tidal tails in merging galaxies and their implications.
Ren J., Zheng X.Z., Valls-Gabaud D., Duc P.-A., Bell E.F., Pan Z., Qin J.,
Shi D.D., Qiao M., He Y., Wen R.
<Mon. Not. R. Astron. Soc., 499, 3399-3409 (2020)>
=2020MNRAS.499.3399R 2020MNRAS.499.3399R (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, dwarf ; Galaxies, interacting ; Galaxies, radius ;
Redshifts ; Optical
Keywords: galaxies: dwarf - galaxies: evolution - galaxies: interactions -
galaxies: peculiar - galaxies: structure
Abstract:
We investigate the properties of long tidal tails using the largest to
date sample of 461 merging galaxies with log(M*/M☉)≥9.5
within 0.2=<z=<1 from the COSMOS survey in combination with Hubble
Space Telescope imaging data. Long tidal tails can be briefly divided
into three shape types: straight (41 per cent), curved (47 per cent),
and plume (12 per cent). Their host galaxies are mostly at late stages
of merging, although 31 per cent are galaxy pairs with projected
separations d>20kpc. The high formation rate of straight tidal tails
needs to be understood as the projection of curved tidal tails
accounts for only a small fraction of the straight tails. We identify
165 tidal dwarf galaxies (TDGs), yielding a TDG production rate of
0.36 per merger. Combined with a galaxy merger fraction and a TDG
survival rate from the literature, we estimate that ∼5 per cent of
local dwarf galaxies (DGs) are of tidal origin, suggesting the tidal
formation is not an important formation channel for the DGs. About
half of TDGs are located at the tip of their host tails. These TDGs
have stellar masses in the range of 7.5=<log(M*/M☉)=<9.5 and
appear compact with half-light radii following the M*-Re relation
of low-mass elliptical galaxies. However, their surface brightness
profiles are generally flatter than those of local disc galaxies. Only
10 out of 165 TDGs have effective radii larger than 1.5kpc and would
qualify as unusually bright ultradiffuse galaxies.
Description:
We adopt the sample of 461 long tidal tail merging galaxies (LTTGs) in
the COSMOS field from Wen & Zheng (2016ApJ...832...90W 2016ApJ...832...90W, Cat.
J/ApJ/832/90). They identified these LTTGs using Hubble Space
Telescope (HST)/ACS F814W (I) imaging data and multiband deep survey
data and catalogues in COSMOS (e.g. Capak et al. 2007ApJS..172...99C 2007ApJS..172...99C,
Cat. II/284; Leauthaud et al. 2007ApJS..172..219L 2007ApJS..172..219L). The HST imaging
data cover an area of 1.64deg2 and provide high-resolution
morphological information in the rest-frame optical for galaxies at
z<1. The stellar mass and photometric redshift catalogues come from
Muzzin et al. (2013ApJS..206....8M 2013ApJS..206....8M, Cat. J/ApJS/206/8), based on the
UltraVISTA survey, providing a total of 154803 Ks-band-detected
sources down to 5σ=23.4mag with a 90 per cent completeness for
point sources.
Using HST/ACS F814W imaging data, we characterize the morphological
properties of our sample LTTGs, including the nuclear separation
distance, the shape and length of tidal tails, and substructures of
tidal tails such as clumps, TDGs, and gaps.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 59 461 The properties and measured tail parameters of
our sample of 461 LTTGs
table2.dat 68 165 The parameters of 165 TDGs identified from 126
merging galaxies with long tidal tails
--------------------------------------------------------------------------------
See also:
J/ApJ/832/90 : Merging galaxies with tidal tails in COSMOS to z=1 (Wen+, 2016)
J/ApJS/206/8 : COSMOS/UltraVISTA Ks-selected catalogs v4.1 (Muzzin+, 2013)
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID Galaxy identifier as in Muzzin et al.
(2013ApJS..206....8M 2013ApJS..206....8M, Cat. J/ApJS/206/8)
8- 18 F11.7 deg RAdeg Right ascension (J2000)
20- 28 F9.7 deg DEdeg Declination (J2000)
30- 33 F4.2 --- z Redshift
35- 39 F5.2 [Msun] logMass Logarithm of the stellar mass
41 A1 --- Nucleus Number of nuclei
(S:single; D:double; M:multiple)
43- 47 F5.2 kpc NucDist ? Nuclear separation distance
49 A1 --- Shape Shape type of tidal tail (1)
51- 55 F5.2 kpc Tail Tail length
57 I1 --- NTDG Number of tidal dwarf galaxies (TDGs) on
tidal tail
59 A1 --- LPTDG Location parameter (2)
--------------------------------------------------------------------------------
Note (1): Shape type of tidal tail as follows:
S = Straight - the tidal tails are straight or slightly curved. The width of
the tails is usually significantly smaller than their length and the
size of their host galaxies
C = Curved - the tidal tails are strongly curved with a shape like 'S', 'U',
or 'V'. The tails are relatively thin and their width is much smaller
than their length. We also include ring-shape tails into this type
P = Plume - the tidal tails spread widely in a form without a certain
figure. Such tails usually have low surface brightness (SB), sticking
to the outskirts of the host galaxies
Note (2): Location parameter as follows:
0 = no TDG
1 = TDGs at the tip of tidal tails
2 = TDGs on tidal tails
3 = TDGs at the tip and on the tidal tails.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 I6 --- ID Galaxy identifier as in Muzzin et al.
(2013ApJS..206....8M 2013ApJS..206....8M, Cat. J/ApJS/206/8)
8- 19 A12 --- Name Tidal dwarf galaxy name (TDG-NNNNNN-N)
21- 30 F10.6 deg RAdeg Right ascension (J2000)
32- 39 F8.6 deg DEdeg Declination (J2000)
41- 44 F4.2 --- z Redshift
46- 50 F5.3 [Msun] logMass Logarithm of the stellar mass
52- 56 F5.3 kpc Re Effective radius
58- 63 F6.3 mag F814WMAG HST/ACS F814W band absolute magnitude
65- 68 F4.2 --- c Concentration parameter (R50/R90) (1)
--------------------------------------------------------------------------------
Note (1): We quantify the concentration of tidal dwarf galaxies using a
concentration parameter c, defined as the ratio between the 90 per
cent-light and 50 per cent-light radii (c=R90/R50)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 05-Sep-2023