2019ApJ...883..171H

Query : 2019ApJ...883..171H

2019ApJ...883..171H - Astrophys. J., 883, 171-171 (2019/October-1)

On the absence of dark matter in dwarf galaxies surrounding the Milky Way.

HAMMER F., YANG Y., WANG J., ARENOU F., PUECH M., FLORES H. and BABUSIAUX C.

Abstract (from CDS):

This paper presents an alternative scenario to explain the observed properties of the Milky Way dwarf Spheroidals (MW dSphs). We show that instead of resulting from large amounts of dark matter (DM), the large velocity dispersions observed along their lines of sight (σlos) can be entirely accounted for by dynamical heating of DM-free systems resulting from MW tidal shocks. Such a regime is expected if the progenitors of the MW dwarfs are infalling gas-dominated galaxies. In this case, gas lost through ram-pressure leads to a strong decrease of self-gravity, a phase during which stars can radially expand, while leaving a gas-free dSph in which tidal shocks can easily develop. The DM content of dSphs is widely derived from the measurement of the dSphs self-gravity acceleration projected along the line of sight. We show that the latter strongly anti-correlates with the dSph distance from the MW, and that it is matched in amplitude by the acceleration caused by MW tidal shocks on DM-free dSphs. If correct, this implies that the MW dSphs would have negligible DM content, putting in question, e.g., their use as targets for DM direct searches, or our understanding of the Local Group mass assembly history. Most of the progenitors of the MW dSphs are likely extremely tiny dIrrs, and deeper observations and more accurate modeling are necessary to infer their properties as well as to derive star formation histories of the faintest dSphs.

Abstract Copyright: © 2019. The American Astronomical Society. All rights reserved.

Journal keyword(s): dark matter - galaxies: dwarf - Galaxy: general

Simbad objects: 54

goto Full paper

goto View the references in ADS

Number of rows : 54
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 MCG-03-01-015 G 00 01 57.9 -15 27 50   11.50 11.10 10.93   ~ 782 2
2 LEDA 5059815 G 00 06 34.279 +15 30 39.04           ~ 32 0
3 NAME Magellanic Stream HVC 00 32 -30.0           ~ 1079 1
4 Z 500-71 AG? 00 42 07.76 +33 24 24.3   15.5       ~ 24 0
5 M 31 AGN 00 42 44.330 +41 16 07.50 4.86 4.36 3.44     ~ 13622 1
6 NAME Sculptor Dwarf Galaxy G 01 00 09.4 -33 42 32   9.79 8.6 8.81   ~ 1498 4
7 NAME Phoenix Dwarf Galaxy Sy1 01 51 06.3 -44 26 41   13.48 13.2 12.69   ~ 575 2
8 NAME Tri II G 02 13 17.40 +36 10 42.4           ~ 164 0
9 NAME Segue 2 G 02 19 16.0 +20 10 31     15.2     ~ 299 0
10 MCG-06-07-001 G 02 39 59.3 -34 26 57   9.02 7.4     ~ 1894 1
11 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 7988 0
12 NAME Reticulum II G 03 35 42.1 -54 02 57           ~ 375 0
13 NAME Eridanus II G 03 44 21.1 -43 32 00           ~ 216 0
14 NAME Cam B G 04 53 07.1 +67 05 57   16.71       ~ 79 0
15 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 19090 0
16 ESO 206-20A G 06 41 36.7 -50 57 58   22.14 11.0 19.47   ~ 1190 0
17 NAME UMa II Galaxy G 08 51 30.0 +63 07 48     13.3     ~ 410 0
18 LEDA 86668 LSB 09 02 53.357 +20 04 32.21   16.9       ~ 108 0
19 NAME Segue 1 G 10 07 03.2 +16 04 25     15.3     ~ 517 1
20 Z 64-73 G 10 08 28.12 +12 18 23.4   11.3 10.0     ~ 1284 1
21 NAME Sextans dSph LSB 10 13 02.9 -01 36 53   12 10.4     ~ 921 0
22 NAME Leo P BiC 10 21 45.123 +18 05 16.89           ~ 268 0
23 NAME UMa I Galaxy G 10 34 52.80 +51 55 12.0     14.4     ~ 355 1
24 NAME Willman 1 G 10 49 21.0 +51 03 00     15.2     ~ 345 0
25 Z 126-111 G 11 13 28.13 +22 09 10.1   12.9 12.0     ~ 899 0
26 NAME Leo V LSB 11 31 09.60 +02 13 12.0     16.0     ~ 234 0
27 NAME Leo IV LSB 11 32 57.0 -00 32 00     15.1     ~ 419 1
28 NGC 3741 AG? 11 36 05.754 +45 17 02.96 15.01 14.55 14.23 14.06   ~ 237 0
29 NAME Crater II Dwarf Galaxy G 11 49 14 -18 24.8           ~ 176 0
30 NAME Hydra II G 12 21 42.1 -31 59 07           ~ 118 0
31 NAME Coma Dwarf Galaxy G 12 26 59.0 +23 54 15     14.1     ~ 482 1
32 Z 216-4 GiG 12 27 40.90 +43 29 44.0 13.75 13.10 12.7 12.33   ~ 270 0
33 NAME Coma P G 12 32 10.30 +20 25 24.0           ~ 38 0
34 NGC 4789A GiC 12 54 05.248 +27 08 58.67 14.37 14.23 13.95 13.84   ~ 614 1
35 NAME CVn II dSph G 12 57 09.6 +34 19 12     16.1     ~ 287 2
36 NAME CVn I dSph G 13 28 03.5 +33 33 21     13.1     ~ 352 1
37 ESO 444-84 GiC 13 37 19.99 -28 02 42.0 16.04 15.34 15.05 15.05 14.9 ~ 133 1
38 NAME Bootes II G 13 58 00.0 +12 51 00     15.4     ~ 269 0
39 NAME Bootes Dwarf Spheroidal Galaxy G 14 00 00.0 +14 30 00     12.8     ~ 491 0
40 Z 318-18 G 15 09 08.0 +67 13 21   13.60 10.6     ~ 1459 0
41 NAME Draco II Gl? 15 52 47.6 +64 33 55           ~ 138 0
42 NAME Hercules Dwarf Galaxy G 16 31 02.0 +12 47 30     14.0     ~ 379 1
43 Z 300-12 G 17 20 14.335 +57 55 16.39   12.40 10.6     ~ 1428 1
44 NAME Galactic Center reg 17 45 39.60213 -29 00 22.0000           ~ 16269 0
45 NAME SDG G 18 55 19.0 -30 32 43   4.5 3.6     ~ 2438 2
46 NGC 6789 AG? 19 16 41.169 +63 58 23.90   13.76       ~ 122 1
47 MCG-02-53-003 G 20 46 51.7 -12 50 54 15.75 15.18 14.83 14.46   ~ 470 1
48 NAME Aquarius 2 G 22 33 55.5 -09 19 39           ~ 66 0
49 NAME Tuc II G 22 51 55.1 -58 34 08           ~ 192 0
50 NAME Grus I G 22 56 42.4 -50 09 48           ~ 126 0
51 NAME Pisces II G 22 58 31.0 +05 57 09     16.3     ~ 283 0
52 NAME Tuc III G 23 56.6 -59 36           ~ 229 0
53 NAME Aquarius Region reg ~ ~           ~ 37 0
54 NAME Local Group GrG ~ ~           ~ 9325 0

To bookmark this query, right click on this link: simbad:objects in 2019ApJ...883..171H and select 'bookmark this link' or equivalent in the popup menu