J/MNRAS/508/1195 The bTFr of MIGHTEE-H I spiral galaxies (Ponomareva+, 2021)
MIGHTEE-H I, the baryonic Tully-Fisher relation over the last billion years.
Ponomareva A.A., Mulaudzi W., Maddox N., Frank B.S., Jarvis M.J.,
Di Teodoro E.M., Glowacki M., Kraan-Korteweg R.C., Oosterloo T.A.,
Adams E.A.K., Pan H., Prandoni I., Rajohnson S.H.A., Sinigaglia F.,
Adams N.J., Heywood I., Bowler R.A.A., Hatfield P.W., Collier J.D.,
Sekhar S.
<Mon. Not. R. Astron. Soc. 508, 1195-1205 (2021)>
=2021MNRAS.508.1195P 2021MNRAS.508.1195P (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Radio sources ; H I data ; Redshifts ;
Stars, masses ; Positional data ; Galaxies, rotation ;
Rotational velocities
Keywords: Galaxies: evolution - Galaxies: kinematics and dynamics -
Galaxies: spiral - dark matter
Abstract:
Using a sample of 67 galaxies from the MeerKAT International GigaHertz
Tiered Extragalactic Exploration Survey Early Science data, we study
the H I-based baryonic Tully-Fisher relation (bTFr), covering a period
of ∼1 billion years (0 =< z =< 0.081). We consider the bTFr based on
two different rotational velocity measures: the width of the global
H I profile and Vout, measured as the outermost rotational velocity
from the resolved H I rotation curves. Both relations exhibit very low
intrinsic scatter orthogonal to the best-fitting relation
(σortho = 0.07 ± 0.01), comparable to the SPARC sample
at z ≃ 0. The slopes of the relations are similar and consistent with
the z ≃ 0 studies (3.66+0.35-0.29 for W50 and
3.47+0.37-0.30 for Vout). We find no evidence that the bTFr has
evolved over the last billion years, and all galaxies in our sample
are consistent with the same relation independent of redshift and the
rotational velocity measure. Our results set-up a reference for all
future studies of the H I-based bTFr as a function of redshift that
will be conducted with the ongoing deep SKA pathfinders surveys.
Description:
Exploration (MIGHTEE), one of the first deep, blind, medium-wide
interferometric surveys for H I ever undertaken (Jarvis et al.
2016mks..confE...6J). It will detect more than 1000 galaxies in H I up
to z = 0.6, thus allowing the systematic study of the evolution of the
neutral gas content of galaxies over the past 5 billion years in
different environments (Ranchod et al. 2021MNRAS.506.2753R 2021MNRAS.506.2753R) using
direct detections and statistical stacking methods (Maddox et al.
2021A&A...646A..35M 2021A&A...646A..35M; Pan et al. 2020MNRAS.491.1227P 2020MNRAS.491.1227P, Pan et al. 2021,
preprint arXiv:2109.04273).
In this work, we use the MIGHTEE Early Science data to perform, for
the first time, a homogeneous study of the H I-based bTFr over the
last billion years (0 =< z =< 0.081). Furthermore, we consider the
bTFr based on two velocity measures: W50 from the corrected width of
the global H I profile, and Vout, the rotational velocity measured
at the outermost point of the resolved H I rotation curves. This
allows us to study how the statistical properties of the bTFr change
with redshift and with different definitions of the rotational
velocity. This is the first study which tests a completely automated
version of 3D Barolo (Di Teodoro & Fraternali 2015MNRAS.451.3021D 2015MNRAS.451.3021D) at
higher redshift, software that was developed to derive H I rotation
curves for the marginally resolved galaxies.
The MIGHTEE is a survey of four well-known deep, extragalactic fields
currently being observed by MeerKAT, the SKA precursor radio
interferometer located in South Africa (Jonas J.L.
2009IEEEP..97.1522J 2009IEEEP..97.1522J). MeerKAT consists of 64 offset Gregorian dishes
(13.5 m diameter main reflector and 3.8 m sub-reflector), and equipped
with three receivers: UHF band (580 < ν < 1015 MHz), L band
(900 < ν < 1670 MHz), and S band (1750 < ν < 3500 MHz).
The MeerKAT data are collected in spectral mode, which makes MIGHTEE a
spectral line, continuum, and polarization survey. The H I emission
project within the MIGHTEE survey (MIGHTEE-H I). The source finding
was performed visually, using the Cube Analysis and Rendering Tool for
Astronomy (Comrie et al. 2020zndo...3746095C), and unguided by the
deep optical information available for these well-studied fields, by
the MIGHTEE-HI group. The total Early Science sample consists of
276 objects each with an identified optical counterpart (Maddox et al.
2021A&A...646A..35M 2021A&A...646A..35M).
We compute baryonic masses, inclination angles and rotational
velocities with a tool for fitting 3D tilted-ring models to
emission-line data cubes of 93 galaxies which is 40 per cent of the
entire sample of the MIGHTEE-H I Early Science Data. Thus, we perform
an assessment of the resulting models by visually inspecting the data,
model and residuals, as well as the resulting rotation curves
projected on the position-velocity diagrams (figs 5 and 6 in Maddox et
al. 2021A&A...646A..35M 2021A&A...646A..35M).
Consequently, SNR and velocity resolution are the main reasons why 3D
Barolo is not able to model the kinematics of some galaxies in our
initial sample. Only 67 of 93 galaxies pass our visual assessment
criteria. We regroup all useful galaxy parameters in the tablem.dat
which forms the final bTFr sample that covers the 0.006 < z < 0.081
redshift range.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablem.dat 102 67 The MIGHTEE-HI baryonic Tully-Fisher relation
sample
--------------------------------------------------------------------------------
See also:
J/A+A/370/765 : HI synthesis observations in UMa cluster (Verheijen+, 2001)
Byte-by-byte Description of file: tablem.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- ID Source identifier name designation
(JHHMMSS.ss+DDMMSS.s) (name)
18- 24 F7.3 deg RAdeg Right Ascension in decimal degrees (J2000)
26- 31 F6.3 deg DEdeg Declination in decimal degrees (J2000)
33- 37 F5.3 GHz Freq [1.313-1.412] observed frequency (freq)
39- 43 F5.3 --- zsp Spectroscopic redshift (z) (1)
45- 50 F6.3 [Msun] logMHI Logarithm of the total H I mass (logMHI) (2)
52- 57 F6.3 [Msun] logM* Logarithm of the stellar mass (logM*) (2)
59- 64 F6.3 deg I3DB Inclination angle from the second run of
the 3D Barolo (I3DB) (3)
66- 71 F6.3 deg iHI Inclination angle measured from the H I
moment-0 maps (iHI) (4)
73- 79 F7.3 deg PA Kinematic position angle of each source (PA)
81- 87 F7.3 km/s Vout Rotational velocity measured as the outermost
from the resolved H I rotation curves
(Vout) (5)
89- 95 F7.3 km/s W50 Measured FWHM of the H I curve (W50) (6)
97-102 F6.3 --- Nbeams Number of beams along the major axis
(Nbeams)
--------------------------------------------------------------------------------
Note (1): For observational H I studies, the redshift of a source is simply
defined as z = νHI/νobs -1 = λobs/λHI-1.
Note (2): The spectral energy distribution (SED) fitting code lephare
(Arnouts et al. 1999MNRAS.310..540A 1999MNRAS.310..540A; Ilbert et al.
2006A&A...457..841I 2006A&A...457..841I) was then used to derive the stellar properties
of the galaxies, such as stellar mass, stellar age, and star
formation rate. We adopt a conservative uncertainty of the stellar
mass for each galaxy of ∼0.1dex (Adams et al. 2021MNRAS.506.4933A 2021MNRAS.506.4933A).
The total H I mass of each galaxy was calculated using the equation
(1) in the section 3.2 H I mass.
Note (3): Please see the section 4.3.1 The sample and results.
While the majority of inclinations are within 10 degrees of iHI
a clear trind is visible, the 3D Barolo tends to overestimate
inclinations for low values of iHI and underestimate them at higher
inclinations. Following this, we perform a second run but this time
we use the iHI values as initial estimate and keep them
unconstrained during the fit. In this case, the modelling recovers
the initial inclination values within 5 degrees range,
the I3DB values are used to correct W50 values.
(i.e comparison between Fig. 2a and 2b. in the section 4.3.1).
Note (4): Any rotational velocity measure should be corrected for the
inclination effect. For face-on discs, inclination corrections become
very large due to the sin(i) dependence. We measure inclination angles
iHI of our sample galaxies using H I moment-0 maps (as described in
Meyer et al. 2017PASA...34...52M 2017PASA...34...52M) as
cos2(iHI) = (b2 - θ2b)/(a2 - θ2a),
where b and a are the minor and major axis of the H I moment-0 map,
measured by fitting an ellipse to the outermost reliable contour equal
to 1M_☉/pc2, θ2b and θ2a are the sizes of
the synthesized beam, used to correct for the beam smearing effect,
which can make galaxies look rounder if they are not well resolved
(Verheijen & Sancisi 2001A&A...370..765V 2001A&A...370..765V, Cat. J/A+A/370/765).
We assign a conservative error on the disc ellipticity of 10 per cent
which results in the mean uncertainty of the iHI of 5 degrees,
(please see section 4.1 Inclinations).
Note (5): The rotational velocity measured at the outermost H I radius
Vout = V(Rout) (i.e Papastergis & Shankar 2016A&A...591A..58P 2016A&A...591A..58P).
Vout measurements are a good representation of Vflat for objects
that are well resolved, and of Vmax for objects that are marginally
resolved. (see the section 4.3.1 The sample and results).
Note (6): Measured at 50 per cent of the peak flux density of the global
H I line profile and if corrected for instrumental broadening and
random motions, gives a good representation of the maximum rotational
velocity measured from a spatially resolved rotation curve as
2Vmax = W50/sin(i) (i.e see fig. 6 in Ponomareva et al.
2016MNRAS.463.4052P 2016MNRAS.463.4052P). For this study, we measure W50 for each galaxy
by fitting the Busy function (Westmeier et al. 2014MNRAS.438.1176W 2014MNRAS.438.1176W),
using multinest to explore the posterior distribution.
Further, see the measure comparison the figure 3 of the section 4.3.1
The sample and results, the two measurements are in excellent
agreement, with the mean of the difference (W50 - 2Vout) equal to
0.02dex, and the standard deviation equal to 0.06dex.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 29-Jul-2024