J/ApJ/905/28 Dark matter mass fraction in gal. through X-ray gas (Harris+, 2020)
Measuring dark matter in galaxies: the mass fraction within five effective
radii.
Harris W.E., Remus R.-S., Harris G.L.H., Babyk I.V.
<Astrophys. J., 905, 28 (2020)>
=2020ApJ...905...28H 2020ApJ...905...28H
ADC_Keywords: Galaxies, nearby; X-ray sources; Stars, masses; Morphology
Keywords: X-ray surveys ; Galaxy masses ; Baryonic dark matter ;
Galaxy dark matter halos
Abstract:
Large galaxies may contain an "atmosphere" of hot interstellar X-ray
gas, and the temperature and radial density profile of this gas can be
used to measure the total mass of the galaxy contained within a given
radius r. We use this technique for 102 early-type galaxies with
stellar masses M*>1010M☉, to evaluate the mass fraction of
dark matter (DM) within the fiducial radius r=5re, denoted
f5=fDM(5re). On average, these systems have a median
f5∼0.8-0.9 with a typical galaxy-to-galaxy scatter ±0.15.
Comparisons with mass estimates made through the alternative
techniques of satellite dynamics (e.g., velocity distributions of
globular clusters, planetary nebulae, satellite dwarfs) as well as
strong lensing show encouraging consistency over the same range of
stellar mass. We find that many of the disk galaxies (S0/SA0/SB0) have
a significantly higher mean f5 than do the pure ellipticals, by
Δf5∼0.1. We suggest that this higher level may be a
consequence of sparse stellar haloes and quieter histories with fewer
major episodes of feedback or mergers. Comparisons are made with the
Magneticum Pathfinder suite of simulations for both normal and
centrally dominant "Brightest Cluster" galaxies. Though the observed
data exhibit somewhat larger scatter at a given galaxy mass than do
the simulations, the mean level of DM mass fraction for all classes of
galaxies is in good first-order agreement with the simulations.
Finally, we find that the group galaxies with stellar masses near
M*∼1011M☉ have relatively more outliers at low f5 than in
other mass ranges, possibly the result of especially effective AGN
feedback in that mass range leading to expansion of their DM halos.
Description:
Babyk+ 2018ApJ...857...32B 2018ApJ...857...32B provide a homogeneous set of measurements
of the total X-ray radial profiles, the gas mass MX, and M5 for
94 relatively massive galaxies nearer than ∼200Mpc. From this list of
94, we have deleted 16 with the most uncertain measurements, leaving
78 systems. We have, however, added 24 more early-type galaxies (ETGs)
with Chandra data newly measured through exactly the same procedures
by I. V. Babyk (2020, in preparation), making a final total of
102 galaxies with measured mass distributions based on their X-ray gas
content.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 97 102 Basic data for target galaxies
table2.dat 92 102 Derived luminosities and masses for observed galaxies
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See also:
B/chandra : The Chandra Archive Log (CXC, 1999-2014)
VII/237 : HYPERLEDA. I. Catalog of galaxies (Paturel+, 2003)
IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)
J/ApJ/591/850 : Radial velocities of M49 globular clusters (Cote+, 2003)
J/ApJS/164/334 : ACS Virgo Cluster Survey. VI (Ferrarese+, 2006)
J/A+A/459/391 : Dynamics of NGC4636 globular cluster syst. (Schuberth+, 2006)
J/ApJS/182/216 : Surface photometry of Virgo ellipticals (Kormendy+, 2009)
J/MNRAS/393/329 : Planetary nebulae of NGC 4494 (Napolitano+, 2009)
J/AJ/137/4956 : Globular clusters around NGC 1407 (Romanowsky+, 2009)
J/ApJ/772/82 : A catalog of globular cluster systems (Harris+, 2013)
J/A+A/620/A111 : Confirmed PN in M87 outer regions (Longobardi+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Galaxy name (1)
12- 29 A18 --- Env Group or cluster environment (2)
31- 34 A4 --- Type Galaxy Hubble Type (1)
36- 39 F4.1 --- T [-4.9/6.4] de Vaucouleurs T-type (1)
41- 50 F10.6 deg RAdeg Right Ascension, decimal degrees (J2000) (1)
52- 61 F10.6 deg DEdeg Declination, decimal degrees (J2000) (1)
63- 67 F5.3 mag ABmag [0.045/1.1] Foreground extinction,
AB in B band (2)
69- 73 F5.1 Mpc Dist [9.5/216.3] Distance (1)
75- 78 F4.1 kpc re [1.5/50] Effective radius (1)
80- 82 F3.1 kpc e_re [0.1/6.6] Uncertainty in re (1)
83 A1 --- u_re [:] Uncertainty flag in re (1)
85- 89 F5.3 mag (B-V)0 [0.5/1.1] Intrinsic (dereddened) integrated
color (1)
91- 97 A7 --- OName Other name or alias
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Note (1): Parameters drawn from the HyperLeda catalog.
Note (2): Parameters drawn from NED (NASA Extragalactic Database).
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Galaxy name
12- 17 F6.2 mag MVt [-24/-18.36] V-band luminosity, MVt
19- 22 F4.2 mag e_MVt [0.09/1.33] Uncertainty in MVt
24- 29 F6.2 mag MKt [-26.64/-21.43] K-band luminosity, MKt
31- 34 F4.2 mag e_MKt [0.03/0.2] Uncertainty in MKt
36- 39 F4.2 --- n [2.24/9.52] Predicted Sersic index
41- 44 F4.2 10+11Msun Mstar [0.05/6.5] Stellar mass
46- 49 F4.2 10+11Msun e_Mstar [0.02/1] Uncertainty in Mstar
51- 56 F6.2 10+11Msun MX [0.01/130] Gas mass
58- 61 F4.2 10+11Msun e_MX [0.0/4.51] Uncertainty in MX
63- 68 F6.2 10+11Msun M5 [2.0/199] Total gravitating mass within 5re
70- 74 F5.2 10+11Msun e_M5 [0.1/35] Uncertainty in M5
76- 80 F5.2 [Msun] logMh [11.52/14.15] log, total halo (virial) mass
82- 86 F5.3 --- f5 [0.05/0.99] Dark matter (DM) mass fraction
(f5=fDM(5re))
88- 92 F5.3 --- e_f5 [0.003/0.14] Uncertainty in f5
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 26-Apr-2022