2018MNRAS.480.2609L

Query : 2018MNRAS.480.2609L

2018MNRAS.480.2609L - Mon. Not. R. Astron. Soc., 480, 2609-2627 (2018/October-3)

Pristine dwarf galaxy survey - I. A detailed photometric and spectroscopic study of the very metal-poor Draco II satellite.

LONGEARD N., MARTIN N., STARKENBURG E., IBATA R.A., COLLINS M.L.M., GEHA M., LAEVENS B.P.M., RICH R.M., AGUADO D.S., ARENTSEN A., CARLBERG R.G., COTE P., HILL V., JABLONKA P., GONZALEZ HERNANDEZ J.I., NAVARRO J.F., SANCHEZ-JANSSEN R., TOLSTOY E., VENN K.A. and YOUAKIM K.

Abstract (from CDS):

We present a detailed study of the faint Milky Way satellite Draco II (Dra II) from deep CFHT/MegaCam broad-band g and i photometry and narrow-band metallicity-sensitive CaHK observations, along with follow-up Keck II/DEIMOS multi-object spectroscopy. Forward modelling of the deep photometry allows us to refine the structural and photometric properties of Dra II: the distribution of stars in colour-magnitude space implies Dra II is old (13.5 ± 0.5 Gyr), very metal-poor, very faint (LV=180+124–72 L☉), and at a distance d = 21.5 ±0.4 kpc. The narrow-band, metallicity-sensitive CaHK Pristine photometry confirms this very low metallicity ([Fe/H] = -2.7 ± 0.1 dex). Even though our study benefits from a doubling of the spectroscopic sample size compared to previous investigations, the velocity dispersion of the system is still only marginally resolved (σvr< 5.9 km s–1 at the 95 per cent confidence level) and confirms that Dra II is a dynamically cold stellar system with a large recessional velocity (<vr>= -342.5+1.1–1.2 km s–1). We further show that the spectroscopically confirmed members of Dra II have a mean proper motion of (µα^*,µ^δ)=(1.26±0.27,0.94±0.28) mas/yr_ in the Gaia DR2 data, which translates to an orbit with a pericentre and an apocentre of 21.3 +0.7–1.0 and 153.8 +56.7–34.7 kpc, respectively. Taken altogether, these properties favour the scenario of Dra II being a potentially disrupting dwarf galaxy. The low-significance extra-tidal features we map around the satellite tentatively support this scenario.

Abstract Copyright: © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): galaxies: dwarf - galaxies: individual: Draco II - Local Group

Nomenclature: Table A1: [LMS2018] JDDD.dddddddd+DD.dddddddd N=51.

CDS comments: DES1 = DES J0034-4902 in Simbad.

Simbad objects: 92

goto Full paper

goto View the references in ADS

Number of rows : 92
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024 		#notes
1 NAME Tuc IV G 00 02.9 -60 51           ~ 69 0
2 [LQS2016] DES J0034-4902 GlC 00 33 59.60 -49 02 19.8           ~ 16 0
3 NAME Sculptor Dwarf Galaxy G 01 00 09.4 -33 42 32   9.79 8.6 8.81   ~ 1358 4
4 NAME Segue 2 G 02 19 16.0 +20 10 31     15.2     ~ 262 0
5 NAME Eri III G 02 22 45.480 -52 17 04.92           ~ 63 0
6 NAME Fornax Dwarf Spheroidal G 02 39 59.3 -34 26 57   9.02 7.4     ~ 1741 1
7 NAME Hor I G 02 55 31.7 -54 07 08           ~ 141 0
8 NAME Reticulum II G 03 35 42.1 -54 02 57           ~ 309 0
9 Cl Melotte 25 OpC 04 29 47.3 +16 56 53           ~ 3074 0
10 NAME SMASH 1 GlC 06 20 59.90 -80 23 44.7           ~ 13 0
11 NAME UMa II Galaxy G 08 51 30.0 +63 07 48     13.3     ~ 374 0
12 NAME Segue 1 G 10 07 03.2 +16 04 25     15.3     ~ 465 1
13 Z 64-73 G 10 08 28.12 +12 18 23.4   11.3 10.0     ~ 1208 1
14 NAME Sextans dSph G 10 13 02.9 -01 36 53   12 10.4     ~ 853 0
15 NAME UMa I Galaxy G 10 34 52.80 +51 55 12.0     14.4     ~ 328 1
16 NAME Willman 1 G 10 49 21.0 +51 03 00     15.2     ~ 320 0
17 Z 126-111 G 11 13 28.13 +22 09 10.1   12.9 12.0     ~ 840 0
18 NAME Leo IV Dwarf Galaxy G 11 32 57.0 -00 32 00     15.1     ~ 383 1
19 NAME Crater Cluster GlC 11 36 16.20 -10 52 38.8           ~ 91 1
20 NAME Coma Dwarf Galaxy G 12 26 59.0 +23 54 15     14.1     ~ 452 1
21 NAME CVn II dSph G 12 57 09.6 +34 19 12     16.1     ~ 263 2
22 NAME Kim 3 Cl* 13 22 45.20 -30 36 03.6           ~ 17 0
23 NGC 5139 GlC 13 26 47.28 -47 28 46.1           ~ 3425 0
24 NAME CVn I dSph G 13 28 03.5 +33 33 21     13.1     ~ 326 1
25 NAME Bootes II G 13 58 00.0 +12 51 00     15.4     ~ 241 0
26 NAME Bootes Dwarf Spheroidal Galaxy G 14 00 00.0 +14 30 00     12.8     ~ 437 0
27 NAME Munoz 1 Cl* 15 01 48.02 +66 58 07.3           ~ 24 0
28 NAME UMi Galaxy G 15 09 08.0 +67 13 21   13.60 10.6     ~ 1358 0
29 [LMS2018] J238.00004167+64.57619444 * 15 51 59.9990720856 +64 34 34.362568812           ~ 1 0
30 [LMS2018] J238.00450000+64.55847222 * 15 52 01.0712313576 +64 33 30.459925980           ~ 1 0
31 [LMS2018] J238.01183333+64.53602778 * 15 52 02.8332681792 +64 32 09.649580172           ~ 1 0
32 [LMS2018] J238.03618333+64.57617500 Pe* 15 52 08.6579308056 +64 34 34.189418352           ~ 1 0
33 [LMS2018] J238.05320833+64.52075000 * 15 52 12.7706078808 +64 31 14.583626040           ~ 1 0
34 [LMS2018] J238.05975000+64.55613889 * 15 52 14.34000 +64 33 22.1000           ~ 1 0
35 [LMS2018] J238.07675000+64.59608333 * 15 52 18.4164338712 +64 35 45.886637724           ~ 2 0
36 [LMS2018] J238.11125000+64.57577778 * 15 52 26.7023014464 +64 34 32.718223596           ~ 2 0
37 [LMS2018] J238.11487862+64.60882637 * 15 52 27.5634467664 +64 36 32.054726052           ~ 2 0
38 [LMS2018] J238.12209840+64.60199650 * 15 52 29.3074009368 +64 36 07.027261560           ~ 2 0
39 [LMS2018] J238.13162500+64.56455556 * 15 52 31.5972857400 +64 33 52.228774728           ~ 2 0
40 [LMS2018] J238.15138333+64.60540000 Pe* 15 52 36.3348662880 +64 36 19.301554224           ~ 3 0
41 [LMS2018] J238.15762500+64.54386111 Pe* 15 52 37.8213269784 +64 32 37.741454052           ~ 1 0
42 [LMS2018] J238.17570833+64.57013889 Pe* 15 52 42.1663820160 +64 34 12.409681404           ~ 3 0
43 [LMS2018] J238.18480597+64.61537726 * 15 52 44.3663401176 +64 36 55.430283708           ~ 2 0
44 [LMS2018] J238.18845833+64.58144444 Pe* 15 52 45.23000 +64 34 53.2000           ~ 1 0
45 [LMS2018] J238.18912917+64.55407222 Pe* 15 52 45.39100 +64 33 14.6600           ~ 1 0
46 NAME Draco II Gl? 15 52 47.6 +64 33 55           ~ 107 0
47 [LMS2018] J238.19866667+64.54908333 Pe* 15 52 47.6770836312 +64 32 56.575988880           ~ 1 0
48 [LMS2018] J238.20966667+64.61985278 Pe* 15 52 50.3309246928 +64 37 11.262268632           ~ 2 0
49 [LMS2018] J238.21103333+64.57847778 * 15 52 50.6483423016 +64 34 42.573624348           ~ 2 0
50 [LMS2018] J238.21533400+64.60644630 * 15 52 51.7125559560 +64 36 23.287565268           ~ 2 0
51 [LMS2018] J238.21795833+64.59575000 Pe* 15 52 52.3067852328 +64 35 44.592187560           ~ 2 0
52 [LMS2018] J238.22337500+64.55341667 Pe* 15 52 53.6111283072 +64 33 12.191943132           ~ 2 0
53 [LMS2018] J238.22362500+64.56244444 Pe* 15 52 53.6676382152 +64 33 44.692265340           ~ 1 0
54 [LMS2018] J238.22609167+64.59788333 * 15 52 54.2592688272 +64 35 52.268243964           ~ 2 0
55 [LMS2018] J238.22750000+64.57172222 Pe* 15 52 54.5970461208 +64 34 18.033482568           ~ 3 0
56 [LMS2018] J238.23100000+64.59677778 * 15 52 55.4353382160 +64 35 48.373618308           ~ 2 0
57 [LMS2018] J238.25460417+64.54189167 Pe* 15 53 01.1153328216 +64 32 30.677431704           ~ 2 0
58 [LMS2018] J238.25691667+64.54466667 Pe* 15 53 01.6622131440 +64 32 40.691106996           ~ 1 0
59 [LMS2018] J238.27908333+64.56091667 Pe* 15 53 06.98000 +64 33 39.3000           ~ 1 0
60 [LMS2018] J238.27975000+64.55630556 Pe* 15 53 07.1491970808 +64 33 22.553501580           ~ 1 0
61 [LMS2018] J238.28841250+64.58997500 * 15 53 09.2316106872 +64 35 23.698188924           ~ 2 0
62 [LMS2018] J238.29208333+64.56011111 Pe* 15 53 10.0949453400 +64 33 36.291523608           ~ 3 0
63 [LMS2018] J238.29766667+64.58597222 Pe* 15 53 11.4339114048 +64 35 09.392064468           ~ 2 0
64 [LMS2018] J238.32470833+64.59466667 WD? 15 53 17.8717987920 +64 35 40.255514664           ~ 4 0
65 [LMS2018] J238.34487500+64.58811111 * 15 53 22.7739848688 +64 35 16.924674984           ~ 1 0
66 [LMS2018] J238.34537500+64.57397222 * 15 53 22.8922612800 +64 34 26.252240016           ~ 2 0
67 [LMS2018] J238.39033333+64.63200000 * 15 53 33.6803282664 +64 37 55.152719112           ~ 1 0
68 [LMS2018] J238.41302083+64.57990000 Pe* 15 53 39.12500 +64 34 47.6400           ~ 2 0
69 [LMS2018] J238.42835417+64.57927222 Pe* 15 53 42.80500 +64 34 45.3800           ~ 1 0
70 [LMS2018] J238.43973971+64.56761491 * 15 53 45.5228971368 +64 34 03.503111124           ~ 2 0
71 [LMS2018] J238.46962500+64.61827778 Pe* 15 53 52.6917900936 +64 37 05.826621900           ~ 1 0
72 [LMS2018] J238.48954167+64.58458333 Pe* 15 53 57.4850390352 +64 35 04.563213144           ~ 1 0
73 [LMS2018] J238.49718375+64.51780965 PM* 15 53 59.4586441032 +64 31 04.662617196           ~ 2 0
74 [LMS2018] J238.50220833+64.58488889 Pe* 15 54 00.5184360312 +64 35 05.568611136           ~ 1 0
75 [LMS2018] J238.51061250+64.55532500 * 15 54 02.4928071288 +64 33 19.208154564           ~ 2 0
76 [LMS2018] J238.51431587+64.57347835 * 15 54 03.4487285856 +64 34 24.521209752           ~ 2 0
77 [LMS2018] J238.52529167+64.59861111 * 15 54 06.0718600536 +64 35 55.106100240           ~ 1 0
78 [LMS2018] J238.54619167+64.52975556 Pe* 15 54 11.0500852200 +64 31 47.253419400           ~ 2 0
79 [LMS2018] J238.55823750+64.56613611 * 15 54 13.9342244280 +64 33 58.197499308           ~ 2 0
80 [LMS2018] J238.56645417+64.50524722 * 15 54 15.9043431840 +64 30 18.991767096           ~ 2 0
81 NAME Hercules Dwarf Galaxy G 16 31 02.0 +12 47 30     14.0     ~ 345 1
82 M 92 GlC 17 17 07.39 +43 08 09.4     6.52     ~ 2115 0
83 NAME Dra dSph G 17 20 14.335 +57 55 16.39   12.40 10.6     ~ 1330 1
84 NAME Indus I Cl* 21 08 49.970 -51 09 48.60           ~ 58 0
85 M 15 GlC 21 29 58.33 +12 10 01.2           ~ 3138 0
86 NAME Gru II G 22 04.1 -46 26           ~ 85 0
87 NAME Balbinot 1 Cl* 22 10 42.819 +14 56 49.03           ~ 27 0
88 NAME Kim 1 Cl* 22 11 41.30 +07 01 31.8           ~ 29 0
89 NAME Pegasus III G 22 24 22.6 +05 25 12           ~ 55 0
90 NAME Pisces II G 22 58 31.0 +05 57 09     16.3     ~ 258 0
91 NAME Tuc III G 23 56.6 -59 36           ~ 189 0
92 NAME Local Group GrG ~ ~           ~ 8387 0

To bookmark this query, right click on this link: simbad:objects in 2018MNRAS.480.2609L and select 'bookmark this link' or equivalent in the popup menu