J/ApJ/801/74 Dark matter profiles in dwarf galaxies (Geringer-Sameth+, 2015)
Dwarf galaxy annihilation and decay emission profiles for dark matter
experiments.
Geringer-Sameth A., Koushiappas S.M., Walker M.
<Astrophys. J., 801, 74 (2015)>
=2015ApJ...801...74G 2015ApJ...801...74G (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Stars, distances ; Models
Keywords: dark matter; galaxies: dwarf; galaxies: fundamental parameters;
galaxies: kinematics and dynamics
Abstract:
Gamma-ray searches for dark matter annihilation and decay in dwarf
galaxies rely on an understanding of the dark matter density profiles
of these systems. Conversely, uncertainties in these density profiles
propagate into the derived particle physics limits as systematic
errors. In this paper we quantify the expected dark matter signal from
20 Milky Way dwarfs using a uniform analysis of the most recent
stellar-kinematic data available. Assuming that the observed stellar
populations are equilibrium tracers of spherically symmetric
gravitational potentials that are dominated by dark matter, we find
that current stellar-kinematic data can predict the amplitudes of
annihilation signals to within a factor of a few for the ultra-faint
dwarfs of greatest interest. On the other hand, the expected signal
from several classical dwarfs (with high-quality observations of large
numbers of member stars) can be localized to the ∼20% level. These
results are important for designing maximally sensitive searches in
current and future experiments using space and ground-based
instruments.
Description:
For the Milky Way's eight most luminous "classical" dwarf galaxies, we
adopt projected halflight radii listed in Table 1 of Walker et al.
(2009, J/AJ/137/3100; original source is Irwin & Hatzidimitriou
1995MNRAS.277.1354I 1995MNRAS.277.1354I). We use the stellar-kinematic data published by
Mateo et al. (2008, J/ApJ/675/201) for Leo I, and by Walker et al.
(2009, J/AJ/137/3100) for Carina, Fornax, Sculptor, and Sextans.
For Draco, Leo II, and Ursa Minor we use stellar-kinematic data
acquired with the Hectochelle spectrograph at the 6.5m MMT. These data
have previously been analyzed by Walker et al. (2009ApJ...704.1274W 2009ApJ...704.1274W)
and Charbonnier et al. (2011, J/MNRAS/418/1526), and will soon be made
public (M. Walker et al., in preparation).
For the Milky Way's less luminous "ultra-faint" satellites discovered
over the past seven years, we make use of published data from a
variety of sources. See section 4.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 85 20 Properties of Milky Way satellites and
stellar-kinematic samples
table3.dat 208 1000 Integrated J-profiles and containment fractions
table4.dat 257 20 Halo profile parameter constraints
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See also:
J/ApJS/209/22 : SSDF survey: IRAC catalogs (Ashby+, 2013)
J/ApJ/770/16 : Spectroscopic members of Segue 2 galaxy (Kirby+, 2013)
J/ApJ/756/79 : Optical phot. in 3 Local Group dwarf galaxies (Sand+, 2012)
J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)
J/MNRAS/418/1526 : Dark matter in dSph galaxies (Charbonnier+, 2011)
J/ApJ/736/146 : Radial velocities of stars in Bootes I (Koposov+, 2011)
J/ApJ/733/46 : Velocity measurements in Segue 1 (Simon+, 2011)
J/ApJ/718/530 : Leo IV g- and r-band photometry (Sand+, 2010)
J/ApJ/710/1664 : BV photometry in Leo IV and Leo V dSphs (de Jong+, 2010)
J/MNRAS/397/1748 : Spectroscopic study of Segue 2 (Belokurov+, 2009)
J/ApJ/694/L144 : Spectroscopic study of Leo V dSph (Walker+, 2009)
J/ApJ/692/1464 : Spectroscopy of Segue 1 (Geha+, 2009)
J/AJ/137/3100 : Radial velocities of 4 dSph galaxies (Walker+, 2009)
J/ApJ/675/201 : Radial velocities of stars near Leo I (Mateo+, 2008)
J/ApJ/663/960 : Radial velocities of Leo I stars (Sohn+, 2007)
J/MNRAS/330/792 : Radial velocity in Draco (Kleyna+, 2002)
J/AJ/113/634 : The survival of Sagittarius dwarf galaxy (Ibata+ 1997)
http://fermi.gsfc.nasa.gov/ssc/data/analysis : Fermi Science Support Center
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name MW satellite name
19- 20 I2 h RAh Hour of right ascension (J2000)
22- 23 I2 min RAm Minute of right ascension (J2000)
25- 28 F4.1 s RAs Second of right ascension (J2000)
30 A1 --- DE- Sign of declination (J2000)
31- 32 I2 deg DEd Degree of declination (J2000)
34- 35 I2 arcmin DEm Arcminute of declination (J2000)
37- 38 I2 arcsec DEs Arcsecond of declination (J2000)
40- 42 I3 kpc Dist [23/417] Distance from the Sun
44- 45 I2 kpc e_Dist [2/19] Dist uncertainty
47- 51 F5.1 mag VMag [-13.4/-1.5] Absolute V-band magnitude
53- 55 F3.1 mag e_VMag [0.2/0.8] VMag uncertainty
57- 59 I3 pc Rh [29/710] Projected half-light radius
61- 62 I2 pc E_Rh [3/77] Positive error on Rh
64- 65 I2 pc e_Rh [3/77] Negative error on Rh
67- 70 I4 --- N [5/2483] Number of member stars with velocity
measurements available (Nsample)
72- 75 I4 pc rmax [119/6272] Maximum galactocentric distance
(rmax)
77- 80 I4 pc E_rmax [45/2616] Positive error on rmax
82- 85 I4 pc e_rmax [18/1366] Negative error on rmax
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name Object identifier
19- 28 F10.8 deg angle [0.01/2.6] Angular separation from
dwarf center
30- 36 F7.4 [GeV2/cm5] logJ-2 The -2σ constraint on logJ (G1)
38- 44 F7.4 [GeV2/cm5] logJ-1 The -1σ constraint on logJ (G1)
46- 52 F7.4 [GeV2/cm5] logJ [15/19.5] Median log10 integrated
J-profile within angle (see Eq. 5)
54- 60 F7.4 [GeV2/cm5] logJ+1 The +1σ constraint on logJ (G1)
62- 68 F7.4 [GeV2/cm5] logJ+2 The +2σ constraint on logJ (G1)
70- 76 F7.4 [GeV/cm2] logJdec-2 The -2σ constraint on logJdec (G1)
78- 84 F7.4 [GeV/cm2] logJdec-1 The -1σ constraint on logJdec (G1)
86- 92 F7.4 [GeV/cm2] logJdec [14/19] Median log10 integrated
Jdecay-profile within angle (see Eq. 6)
94-100 F7.4 [GeV/cm2] logJdec+1 The +1σ constraint on logJdec (G1)
102-108 F7.4 [GeV/cm2] logJdec+2 The +2σ constraint on logJdec (G1)
110-118 E9.3 --- cf-2 The -2σ constraint on cf-2 (G1)
120-128 E9.3 --- cf-1 The -1σ constraint on cf-1 (G1)
130-138 E9.3 --- cf [0.002/1] Median fraction of total
J contained within angle
140-148 E9.3 --- cf+1 The +1σ constraint on cf+1 (G1)
150-158 E9.3 --- cf+2 The +2σ constraint on cf+2 (G1)
160-168 E9.3 --- cfdec-2 The -2σ constraint on cfdec-2 (G1)
170-178 E9.3 --- cfdec-1 The -1σ constraint on cfdec-1 (G1)
180-188 E9.3 --- cfdec [0.0001/1] Median fraction of total
Jdecay contained within angle
190-198 E9.3 --- cfdec+1 The +1σ constraint on cfdec+1 (G1)
200-208 E9.3 --- cfdec+2 The +2σ constraint on cfdec+2 (G1)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Name Object identifier
19- 25 F7.4 [Msun/pc3] rhos-2 The -2σ constraint on rhos (G1)
27- 33 F7.4 [Msun/pc3] rhos-1 The -1σ constraint on rhos (G1)
35- 41 F7.4 [Msun/pc3] rhos [-2.4/-0.4] Median log10(ρs) (1)
43- 49 F7.4 [Msun/pc3] rhos+1 The +1σ constraint on rhos (G1)
51- 57 F7.4 [Msun/pc3] rhos+2 The +2σ constraint on rhos (G1)
59- 65 F7.4 [pc] rs-2 The -2σ constraint on rs (G1)
67- 73 F7.4 [pc] rs-1 The -1σ constraint on rs (G1)
75- 81 F7.4 [pc] rs [2.5/4] Median log10(rs) (1)
83- 89 F7.4 [pc] rs+1 The +1σ constraint on rs (G1)
91- 97 F7.4 [pc] rs+2 The +2σ constraint on rs (G1)
99-105 F7.4 --- alpha-2 The -2σ constraint on alpha (G1)
107-113 F7.4 --- alpha-1 The -1σ constraint on alpha (G1)
115-121 F7.4 --- alpha [1.4/2.2] Median α (1)
123-129 F7.4 --- alpha+1 The +1σ constraint on alpha (G1)
131-137 F7.4 --- alpha+2 The +2σ constraint on alpha (G1)
139-145 F7.4 --- beta-2 The -2σ constraint on beta (G1)
147-153 F7.4 --- beta-1 The -1σ constraint on beta (G1)
155-161 F7.4 --- beta [5.2/7] Median β (1)
163-169 F7.4 --- beta+1 The +1σ constraint on beta (G1)
171-177 F7.4 --- beta+2 The +2σ constraint on beta (G1)
179-185 F7.4 --- gamma-2 The -2σ constraint on gamma (G1)
187-193 F7.4 --- gamma-1 The -1σ constraint on gamma (G1)
195-201 F7.4 --- gamma [0.4/1] Median γ (1)
203-209 F7.4 --- gamma+1 The +1σ constraint on gamma (G1)
211-217 F7.4 --- gamma+2 The +2σ constraint on gamma (G1)
219-225 F7.4 --- betaa-2 The -2σ constraint on betaa (G1)
227-233 F7.4 --- betaa-1 The -1σ constraint on betaa (G1)
235-241 F7.4 --- betaa [-0.8/0.6] Median -log10(1-βa) (2)
243-249 F7.4 --- betaa+1 The +1σ constraint on betaa (G1)
251-257 F7.4 --- betaa+2 The +2σ constraint on betaa (G1)
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Note (1): Parameters of the dark matter density ρ(r) given by Eq.(7):
ρ(r) = ρs (r/rs)-γ
[1+(r/rs)α]γ-β/α
Note (2): the anisotropy parameter βa is defined by Eq.(12) from
the velocity dispersion profile (ur uθ uφ) as:
βa(r) = 1 - 2<uθ2>/<ur2>
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Global notes:
Note (G1): the points correspond to:
-2σ = 2.3 percentile;
-1σ = 15.9 percentile;
+1σ = 84.1 percentile;
+2σ = 97.7 percentile.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 15-Jul-2015