J/A+A/706/A64 Matter properties ALFALFA galaxies with TNG100 code (Yang+, 2026)
Dark matter in ALFALFA galaxies. Investigating galaxy-halo connection.
Yang M., Zhu L., Yu N., Lei Y., Cai R., Wang J., Zheng Z.
<Astron. Astrophys. 706, A64 (2026)>
=2026A&A...706A..64Y 2026A&A...706A..64Y (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby; Galaxies, rotation; H I data ; Spectroscopy ;
Positional data ; Galaxies, radio ; Radio sources ;
Stars, masses ; Galaxies, radius ; Line Profiles ;
Rotational velocities
Keywords: galaxies: formation - galaxies: halos -
galaxies: kinematics and dynamics
Abstract:
This paper aims to investigate the galaxy-halo connection using a
large sample of individual galaxies with HI-integrated spectra. We
determined their dark matter content by applying a dynamical method
based on HI line widths measured with the curve-of-growth
technique, together with inclination corrections inferred from optical
images.
We built a sample of 2453 gas-rich, predominantly late-type galaxies
spanning a stellar mass range of 108.7M☉ to 1011.4M☉ by
matching them one-to-one with their counterparts from the ALFALFA
survey and the TNG100 simulation, ensuring a direct match of stellar
mass and HI radius. We generated mock images and mock
HI-integrated spectra for TNG100 galaxies, and applied the same
dynamical method to both ALFALFA and TNG100 mock galaxies to infer
their dark matter masses.
Across all stellar mass bins, ALFALFA galaxies exhibit lower median
dark matter masses than the mock TNG100 simulation results. In each
bin, this offset is driven by a tail of galaxies with comparatively
low dark matter content, which becomes more prominent toward higher
stellar masses. In the highest mass bin (M*>1011M☉), late-type
ALFALFA galaxies show a median dark matter mass that is 23% lower than
that of their counterparts in the TNG100 dark-matter-only simulation,
with 32% of ALFALFA galaxies having MDM(<RHI)<1011.5M☉,
compared to 17% in the mock TNG100 sample. These results suggest that
a larger fraction of massive late-type galaxies reside in relatively
less massive dark matter haloes than predicted by the TNG100
simulation.
Description:
The two complementary data tables, the alfa4844.dat is the
observational table compiles physical parameters for ALFALFA parent
galaxies in the paper, with stellar and HI masses, HI size, axis
ratio, inclination, and dynamical masses adopted from Yu et al.
(2022ApJS..261...21Y 2022ApJS..261...21Y, Cat. J/ApJS/261/21). The dark matter mass within
the HI size is derived from these quantities. The simulation-based
tng2453.dat contains data from the TNG100 simulation. For each galaxy,
we provide both the "true" masses directly derived from the particle
distribution (e.g. true MHI, Mstar, MDM within a given radius)
and the corresponding mock-observed measurements, which emulate the
observational procedures and limitations. These two tables enable
direct comparison between observationally inferred and theoretically
known galaxy halo properties, with a focus on assessing uncertainties
and biases in measuring baryonic and dark matter distributions.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
alfa4844.dat 152 4844 ALFALFA parent sample with physical and
structural parameters
tng2453.dat 231 2453 TNG100 galaxies with matched mock observations
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See also:
J/A+A/544/A65 : GALEX Arecibo SDSS survey. VI. (Catinella+, 2012)
J/ApJS/261/21 : HI emission line profile of ALFALFA nearby galaxies
(Yu+, 2022)
J/ApJ/861/49 : ALFALFA extragalactic HI source catalog (Haynes+, 2018)
J/AJ/160/271 : A catalog of ∼30000 galaxies with ALFALFA-SDSS
(Durbala+, 2020)
J/AJ/142/170 : ALFALFA survey: the α.40 HI source catalog
(Haynes+, 2011)
J/MNRAS/460/2143 : HI size-mass relation of galaxies (Wang+, 2016)
J/MNRAS/436/34 : GALEX Arecibo SDSS survey. Final data release
(Catinella+, 2013)
J/MNRAS/403/683 : GALEX Arecibo SDSS survey (GASS) (Catinella+, 2010)
VIII/77 : HI spectral properties of galaxies (Springob+, 2005)
VII/26 : Uppsala General Catalogue of Galaxies (UGC) (Nilson 1973)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16)
(Ahumada+, 2020)
Byte-by-byte Description of file: alfa4844.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- AGC Arecibo General Catalog ID (AGC) (1)
8- 18 F11.7 deg RAdeg Right Ascension of the optical counterpart
(J2000) (RA)
20- 29 F10.7 deg DEdeg Declination of the optical counterpart (J2000)
(DEC)
31- 36 F6.2 Mpc Dist Luminosity distance from the ALFALFA catalog
(Dist)
38- 43 F6.2 Mpc e_Dist Error in distance (e_Dist)
45- 52 F8.3 [Msun] logM* Stellar mass (logMstar) (2)
54- 63 F10.3 [Msun] e_logM* Error in stellar mass (e_logMstar)
65- 70 F6.3 [Msun] logMHI HI mass total (logMHI) (3)
72- 79 F8.3 [Msun] e_logMHI Error in HI mass (e_logMHI)
81- 85 F5.2 kpc RHI HI size radius of HI disk (RHI) (4)
87- 91 F5.2 kpc e_RHI Error in HI size (e_RHI)
93- 95 F3.1 --- b/a Axis ratio in optical r-band image (b/a)
97-100 F4.1 deg i Optical inclination angle (incl)
102-107 F6.1 deg e_i Error in inclination (e_incl)
109-115 F7.3 [Msun] logMdyn Dynamical mass within RHI (logMdyn)
117-125 F9.3 [Msun] e_logMdyn Error in dynamical mass (e_logMdyn)
127-136 F10.3 [Msun] logMHIr HI mass enclosed within RHI (logMHI_rhi)
138-143 F6.3 [Msun] logMDM Dark matter mass within R_HI (logMdm) (5)
145-152 F8.3 [Msun] e_logMDM Error in dark matter mass (e_logMdm)
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Note (1): UGC/AGC numbers from a private database of extragalactic objects
maintained by M.P. Haynes and R. Giovanelli (see Cat. VIII/77).
The AGC entry normally corresponds to the optical counterpart of
the HI source. Numbers lower than 100000 are UGC numbers (Cat. VII/26).
Note (2): Stellar mass and SFR from spectral energy distribution fitting
(Salim et al. 2018ApJ...859...11S 2018ApJ...859...11S), scaled to the distance of ALFALFA.
Note (3): Following MHI = 2.36*105Dist2*FHI in solar units, Roberts
(1962AJ.....67..437R 1962AJ.....67..437R), for a distance uncertainty of 10% and a flux
uncertainty of 15%, the typical uncertainty of logMHI is 0.11dex.
Note (4): Calculated from the HI mass-size relation of Wang et al.
(2016MNRAS.460.2143W 2016MNRAS.460.2143W, Cat. J/MNRAS/460/2143).
Note (5): We computed dark matter mass in linear space before log scale with
MDM = Mdyn - 1.07*MHI,rhi.
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Byte-by-byte Description of file: tng2453.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 I10 --- IDsbHalo TNG100 subhalo ID (subhalo_id)
12- 19 I8 --- IDgroup TNG100 group ID (group_id)
21- 31 I11 --- AGC The 1-to-1 Matched AGC number (matched_AGC)
33- 38 F6.2 Mpc Dist Luminosity distance from the ALFALFA
catalog (Dist)
40- 44 F5.2 kpc Re Effective radius 3D (Re)
46- 54 F9.3 [Msun] logM*5Re Stellar mass within 5Re (Mstar_5Re)
56- 66 F11.3 kpc RHI HI size defined by definition (RHI_defined)
68- 85 F18.3 [Msun] logMHI2.2R HI mass within 2.2 RHI defined
(MHI2.2RHIdefined)
87- 92 F6.3 kpc RHIw HI size estimated by Wang et al.
(2016MNRAS.460.2143W 2016MNRAS.460.2143W,
Cat. J/MNRAS/460/2143) (R_HI)
94-102 F9.3 [Msun] logM*R Stellar mass within R_HI (Mstar_RHI)
104-111 F8.3 [Msun] logMgasR Total gas mass within R_HI (Mgas_RHI)
113-119 F7.3 [Msun] logMDMR Dark matter mass within R_HI (Mdm_RHI)
121-128 F8.3 [Msun] logMdynR Total dynamical mass within R_HI (Mdyn_RHI)
130-143 F14.3 [Msun] logMdoR Mass for counterparts in dark-matter-only
simulation (MdarkonlyRHI)
145-156 A12 --- Paxis LOS projection axis in TNG100
(project_axis)
158-162 F5.3 --- b/a Projected axis ratio of r-band (b/a)
164-167 F4.1 deg i Inclination angle using Sanchez-Janssen
et al. (2010) (incl) (1)
169-174 F6.1 deg e_i Error on inclination (e_incl)
176-184 F9.1 km/s W85 Deprojected W85 HI linewidth of mock HI
spectra (W85_cor3d)
186-196 F11.1 km/s e_W85 Error on W85 (eW85cor3d)
198-202 F5.1 km/s Vrot Rotation velocity (Vrot) (2)
204-209 F6.1 km/s e_Vrot Error on Vrot (e_Vrot)
211-219 F9.3 [Msun] logMdynm Dynamical mass inferred from mock
observation (Mdyn_mock)
221-231 F11.3 [Msun] e_logMdynm Error on logMdynm (eMdynmock)
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Note (1): Inclination is derived from projected b/a assuming an intrinsic
flattening using Sanchez-Janssen et al. (2010MNRAS.406L..65S 2010MNRAS.406L..65S).
Note (2): Vrot is derived from W85 corrected for inclination and calibrated in
this previous and actual work.
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Acknowledgements:
Meng Yang, myang(at)shao.ac.cn
Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai,
China
(End) Luc Trabelsi [CDS] 17-Dec-2025