J/ApJ/816/L14 Tully-Fisher relation in disk galaxies from SPARC (Lelli+, 2016)
The small scatter of the baryonic Tully-Fisher relation.
Lelli F., McGaugh S.S., Schombert J.M.
<Astrophys. J., 816, L14 (2016)>
=2016ApJ...816L..14L 2016ApJ...816L..14L (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Galaxies, rotation ; Rotational velocities
Keywords: dark matter - galaxies: evolution - galaxies: formation -
galaxies: irregular - galaxies: kinematics and dynamics -
galaxies: spiral
Abstract:
In a Λ cold dark matter (ΛCDM) cosmology, the baryonic
Tully-Fisher relation (BTFR) is expected to show significant intrinsic
scatter resulting from the mass-concentration relation of dark matter
halos and the baryonic-to-halo mass ratio. We study the BTFR using a
sample of 118 disk galaxies (spirals and irregulars) with data of the
highest quality: extended HI rotation curves (tracing the outer
velocity) and Spitzer photometry at 3.6µm (tracing the stellar
mass). Assuming that the stellar mass-to-light ratio (Υ*) is
nearly constant at 3.6µm, we find that the scatter, slope, and
normalization of the BTFR systematically vary with the adopted
Υ*. The observed scatter is minimized for
Υ*≳0.5M☉/L☉, corresponding to nearly maximal
disks in high-surface-brightness galaxies and BTFR slopes close to ∼4.
For any reasonable value of Υ*, the intrinsic scatter is
∼0.1dex, below general ΛCDM expectations. The residuals show no
correlations with galaxy structural parameters (radius or surface
brightness), contrary to the predictions from some semi-analytic
models of galaxy formation. These are fundamental issues for
ΛCDM cosmology.
Description:
This work is based on the Spitzer Photometry and Accurate Rotation
Curves (SPARC) data set, presented in detail in Lelli et al. 2016
(Cat. J/AJ/152/157). In short, we collected more than 200 high-quality
HI rotation curves of disk galaxies from previous compilations, large
surveys, and individual studies.
Subsequently, we searched the Spitzer archive for 3.6µm images of
these galaxies. We found 173 objects with useful [3.6] data.
For the sake of this study, we exclude starburst dwarf galaxies (eight
objects from Lelli et al. 2014, Cat. J/A+A/566/A71, and Holmberg II
from Swaters et al. 2009A&A...493..871S 2009A&A...493..871S) because they have complex HI
kinematics and are likely involved in recent interactions (Lelli et
al. 2014MNRAS.445.1694L 2014MNRAS.445.1694L). This reduces our starting sample to 164
objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
figure2.dat 70 118 *Data behind Figure 2
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Note on figure2.dat: Figure 2 in the paper shows Baryonic Tully-Fisher Relation
(BTFR) adopting Υ*=0.5M☉/L☉ (top panels), and the
residuals from the error-weighted fits versus the galaxy effective radius
(bottom panels).
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See also:
J/ApJ/827/L19 : Central surface densities in SPARC disk galaxies (Lelli+, 2016)
J/AJ/152/157 : Mass models for 175 disk galaxies with SPARC (Lelli+, 2016)
J/AJ/147/134 : Tully-Fisher relation for S4G galaxies (Zaritsky+, 2014)
J/A+A/566/A71 : HI study of 18 nearby dwarf galaxies (Lelli+, 2014)
J/ApJ/765/94 : Calibration of the mid-IR Tully-Fisher relation (Sorce+, 2013)
J/ApJ/669/821 : CO Tully-Fisher relation for host galaxies of QSOs (Ho+, 2007)
J/AJ/134/945 : Tully-Fisher relation for SDSS galaxies (Pizagno+, 2007)
Byte-by-byte Description of file: figure2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Galaxy name
13- 18 F6.2 Mpc Dist [0.98/127.8] Galaxy distance
20- 24 F5.2 Mpc e_Dist [0.05/12.8] Mean error on Dist
26 I1 --- f_Dist [1/5] Method flag on Dist (1)
28- 32 F5.2 [Msun] logMb [7.98/11.43] Log of the baryonic mass (Mb) (2)
34- 38 F5.2 [Msun] e_logMb [0.06/0.28] Mean error on logMb
40- 44 F5.2 [km/s] logVf [1.53/2.52] Log of rotation velocity (Vf) (3)
46- 50 F5.2 [km/s] e_logVf [0.01/0.11] Mean error on logVf
52- 56 F5.2 --- Fg [0.02/0.95] Gas fraction (fg=Mg/Mb) (4)
58- 64 F7.2 Msun/pc2 SBeff [3.8/1659] Effective stellar surface
brightness (4)
66- 70 F5.2 kpc Reff [0.32/13.61] Effective stellar radius
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Note (1): The 118 galaxies with accurate values of Vf have different types of
distance estimates (see Section 2.3) defined as follows:
1 = Hubble-Flow assuming H0=73km/s/Mpc and correcting for Virgo-centric
infall;
2 = Magnitude of the tip of the red giant branch;
3 = Cepheids magnitude-period relation;
4 = Ursa Major cluster of galaxies;
5 = Supernovae light curve.
Note (2):
Assuming a stellar mass-to-light ratio of 0.5 at 3.6µm. We estimate the
baryonic mass as:
Mb=Mg+Υ*L[3.6] (Eq.(4) in the paper), where
Mg is the gas mass,
L[3.6] is the [3.6] luminosity,
and Υ* is the stellar mass-to-light ratio.
Please refer to Section 2.3 in the paper for further details.
Note (3): Mean velocity along the flat part of the rotation curve. See Section
2.2 for additional details.
Note (4): Assuming a stellar mass-to-light ratio of 0.5 at 3.6µm.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 23-Feb-2017