2021ApJ...912..157R

Query : 2021ApJ...912..157R

2021ApJ...912..157R - Astrophys. J., 912, 157-157 (2021/May-2)

Extreme r-process enhanced stars at high metallicity in Fornax.

REICHERT M., HANSEN C.J. and ARCONES A.

Abstract (from CDS):

We present and discuss three extremely r-process enhanced stars located in the massive dwarf spheroidal galaxy Fornax. These stars are very unique with an extreme Eu enrichment (1.25 <= [Eu/Fe]<=1.45) at high metallicities (-1.3 <= [Fe/H]<=-0.8). They have the largest Eu abundances ever observed in a dwarf galaxy opening new opportunities to further understand the origin of heavy elements formed by the r-process. We derive stellar abundances of Co, Zr, La, Ce, Pr, Nd, Er, and Lu using one-dimensional, local thermodynamic equilibrium codes and model atmospheres in conjunction with state-of-the art yield predictions. We derive Zr in the largest sample of stars (105) known to date in a dwarf galaxy. Accurate stellar abundances combined with a careful assessment of the yield predictions have revealed three metal-rich stars in Fornax showing a pure r-process pattern. We define a new class of stars, namely, Eu-stars, as r-II stars (i.e., [Eu/Fe] > 1) at high metallicities (i.e., [Fe/H] >= -1.5). The stellar abundance pattern contains Lu, observed for the first time in a dwarf galaxy, and reveals that a late burst of star formation has facilitated extreme r-process enhancement late in the galaxy's history (<4 Gyr ago). Due to the large uncertainties associated with the nuclear physics input in the yield predictions, we cannot yet determine the r-process site leading to the three Eu-stars in Fornax. Our results demonstrate that extremely r-rich stars are not only associated with ultra-faint low-mass dwarf galaxies, but can be born also in massive dwarf galaxies.

Abstract Copyright: © 2021. The American Astronomical Society. All rights reserved.

Journal keyword(s): Chemical abundances - R-process - Nucleosynthesis - Fornax dwarf spheroidal galaxy - Dwarf spheroidal galaxies - Chemically peculiar stars

Simbad objects: 116

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Number of rows : 116
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 NAME Sculptor Dwarf Galaxy G 01 00 09.4 -33 42 32   9.79 8.6 8.81   ~ 1498 4
2 FBMC Sculptor 11 RG* 01 00 16.2940096800 -33 42 37.232341452   18.86 16.995   15.525 C? 23 0
3 2MASS J02372020-3446458 RG* 02 37 20.2055116752 -34 46 46.016190984   20.200 18.59   17.11 ~ 7 0
4 2MASS J02373287-3440420 RG* 02 37 32.8750534440 -34 40 42.022468020   20.096 18.54   17.02 ~ 9 0
5 [LDH2014] Fnx-mem0675 RG* 02 37 55.7611682352 -34 50 25.259159580     18.756   17.354 ~ 4 0
6 2MASS J02375588-3447160 RG* 02 37 55.8848223048 -34 47 16.038093120   20.157 18.41   16.78 ~ 10 0
7 2MASS J02380140-3440114 RG* 02 38 01.3998362352 -34 40 11.651514708   20.218 18.71   17.17 ~ 6 0
8 2MASS J02380246-3441008 RG* 02 38 02.4569856624 -34 41 00.826153296   20.140 18.43   16.86 ~ 10 0
9 DK 4 RG* 02 38 09.0567945672 -34 51 07.095620556   20.268 18.50   16.92 ~ 12 0
10 [LDH2014] Fnx-mem0715 RG* 02 38 11.1117356520 -34 53 20.642206200   20.257 18.722   17.245 ~ 4 0
11 FBW J023821.3-343618 RG* 02 38 21.3337513392 -34 36 18.281970864   20.142 18.335   16.393 ~ 8 0
12 2MASS J02382200-3446368 RG* 02 38 22.0137234888 -34 46 37.015779864   20.119 18.62   17.14 ~ 10 0
13 2MASS J02382246-3445061 RG* 02 38 22.4564152056 -34 45 06.389078976   20.123 18.576   17.014 ~ 8 0
14 [LDH2014] Fnx-rgb0553 RG* 02 38 25.2111651888 -34 41 24.258880824   20.284 18.655   17.033 ~ 4 0
15 2MASS J02382648-3442367 RG* 02 38 26.4947315256 -34 42 36.875745756   20.291 18.606   16.979 ~ 7 0
16 2MASS J02383095-3456544 RG* 02 38 30.9502123872 -34 56 54.274188048   20.178 18.48   16.91 ~ 10 0
17 [WMO2009] For-2122 RG* 02 38 35.0324152944 -34 42 40.665347532   20.039 18.42   16.93 ~ 8 0
18 [WMO2009] For-1095 RG* 02 38 35.0341735680 -34 41 38.125612608   20.254 18.56   17.09 ~ 6 0
19 2MASS J02383555-3444024 RG* 02 38 35.5497063384 -34 44 02.616618768   20.190 18.47   16.96 ~ 9 0
20 [WMO2009] For-1097 RG* 02 38 40.1836241568 -34 39 12.095578980   20.056 18.3   16.67 ~ 10 0
21 2MASS J02384060-3453308 * 02 38 40.6017221640 -34 53 30.806323548   20.175 18.5   16.95 ~ 9 0
22 [WMF2009] F 31013 RG* 02 38 41.1151886592 -34 44 20.558729004   19.672 18.157   16.653 ~ 8 0
23 [LHT2010] BL146 RG* 02 38 41.7927890574 -34 28 58.602098922           ~ 6 0
24 DK 9 RG* 02 38 42.1786995120 -34 47 40.480134576   20.125 18.415   16.791 ~ 10 0
25 [LHT2010] BL084 RG* 02 38 42.9879986730 -34 25 49.436497802           ~ 5 0
26 2MASS J02384297-3450564 RG* 02 38 42.9886796592 -34 50 56.333753232   20.316 18.62   17.07 ~ 10 0
27 2MASS J02384346-3432054 RG* 02 38 43.4731454496 -34 32 05.507582532     18.29   16.82 ~ 11 0
28 [LHT2010] BL163 RG* 02 38 43.5737449585 -34 32 25.631794706           ~ 6 0
29 [LHT2010] BL147 RG* 02 38 44.0541787219 -34 30 52.046563303           ~ 6 0
30 2MASS J02384461-3442334 RG* 02 38 44.6103869736 -34 42 33.440355180   20.185 18.55   17.1 ~ 6 0
31 [LDH2014] Fnx-mem0556 RG* 02 38 45.5685554664 -34 41 45.309482916   20.159 18.666   17.171 ~ 5 0
32 2MASS J02384635-3441147 RG* 02 38 46.3487515392 -34 41 14.899686648   20.132 18.62   17.25 ~ 7 0
33 2MASS J02384789-3439397 RG* 02 38 47.8923633984 -34 39 39.734023824   20.149 18.44   16.77 ~ 9 0
34 2MASS J02385297-3447013 RG* 02 38 52.9645447128 -34 47 01.407091596   19.677 18.14   16.73 ~ 9 0
35 GB07 Fnx20 RG* 02 38 53.6508957336 -34 33 04.826280780     18.457   16.71 ~ 12 0
36 2MASS J02385377-3430067 RG* 02 38 53.7843539640 -34 30 06.884683200     18.39   16.80 ~ 12 0
37 2MASS J02385552-3447211 RG* 02 38 55.5159454344 -34 47 21.150630420   20.238 18.63   17.2 ~ 6 0
38 [LHT2010] BL100 RG* 02 38 56.0321011320 -34 24 45.216767030           ~ 6 0
39 GB07 Fnx28 RG* 02 38 57.2199235584 -34 35 40.175367396     18.577     ~ 7 0
40 GB07 Fnx13 RG* 02 39 00.3186336432 -34 30 30.293164044     18.566   17.01 ~ 8 0
41 GB07 Fnx30 RG* 02 39 01.5753059085 -34 36 49.014459164     18.529   16.99 ~ 11 0
42 [WMO2009] For-1208 * 02 39 01.7737636416 -34 27 19.618725420     18.59   17.07 ~ 7 0
43 2MASS J02390409-3423531 RG* 02 39 04.0975378152 -34 23 53.136525732     18.44   16.98 ~ 8 0
44 GB07 Fnx05 RG* 02 39 04.3406484840 -34 25 19.173161388     18.390   16.96 ~ 9 0
45 2MASS J02390563-3426310 RG* 02 39 05.6468205096 -34 26 31.070375952     18.57   17.12 ~ 7 0
46 [LHT2010] BL158 RG* 02 39 06.8643906183 -34 35 45.982262223           ~ 6 0
47 GB07 Fnx31 RG* 02 39 08.1870665856 -34 36 53.680842684     18.274     ~ 8 0
48 GB07 Fnx16 RG* 02 39 08.5373495328 -34 30 55.662476112     18.398   16.92 ~ 8 0
49 GB07 Fnx09 RG* 02 39 11.0174908200 -34 28 34.794801984     18.527   17.07 ~ 9 0
50 2MASS J02391107-3439090 RG* 02 39 11.0832316368 -34 39 09.089157744     18.36   16.74 ~ 8 0
51 GB07 Fnx15 RG* 02 39 11.5950166128 -34 30 45.025631532     18.496   16.9 ~ 9 0
52 2MASS J02391340-3440163 RG* 02 39 13.4044386936 -34 40 16.332750300     18.44   16.91 ~ 6 0
53 GB07 Fnx10 RG* 02 39 13.9746891112 -34 28 36.602924029   20.039 18.550 17.708 16.99 ~ 10 0
54 2MASS J02391438-3422418 RG* 02 39 14.3673579432 -34 22 42.008681496     18.37   16.84 ~ 9 0
55 GB07 Fnx26 RG* 02 39 14.3827552392 -34 34 42.637844820     18.757   17.11 ~ 12 0
56 [LHT2010] BL104 RG* 02 39 14.6216479830 -34 23 21.500656227           ~ 6 0
57 [WMO2009] For-0391 * 02 39 14.8074249264 -34 27 30.365297820     18.53   17.02 ~ 7 0
58 2MASS J02391551-3430468 RG* 02 39 15.5049244920 -34 30 46.890998244     18.61   17.06 ~ 7 0
59 GB07 Fnx12 RG* 02 39 16.0444264824 -34 30 13.352608044     18.496   16.96 ~ 12 0
60 [LHT2010] BL138 RG* 02 39 16.2349562521 -34 37 00.605900154           ~ 8 0
61 [LHT2010] BL204 * 02 39 16.2620103072 -34 32 30.101458128     18.65   17.17 ~ 7 0
62 2MASS J02391678-3434501 RG* 02 39 16.7878313544 -34 34 50.132894268   20.071 18.46 17.657 16.9 ~ 8 0
63 GB07 Fnx17 RG* 02 39 17.8282697688 -34 30 57.039860448     18.702   16.98 ~ 9 0
64 DK 39 RG* 02 39 19.6328273496 -34 24 49.616298000   20.31 18.5   16.94 ~ 9 0
65 GB07 Fnx18 RG* 02 39 20.2378506168 -34 31 57.280700280     18.533   16.99 ~ 8 0
66 GB07 Fnx25 RG* 02 39 24.8304854804 -34 34 38.274693223     18.577   17.01 ~ 10 0
67 GB07 Fnx33 RG* 02 39 27.6904648656 -34 37 48.791442756   19.829 18.347 17.448   ~ 13 0
68 GB07 Fnx23 RG* 02 39 28.0529840088 -34 34 01.280850276   19.948 18.580 17.693 17.02 ~ 12 0
69 2MASS J02392937-3426359 RG* 02 39 29.3612731224 -34 26 35.909558484   20.023 18.417 17.513 16.76 ~ 14 0
70 GB07 Fnx29 RG* 02 39 30.8431991376 -34 35 45.258531468   20.192 18.671 17.746 17.01 ~ 12 0
71 GB07 Fnx03 RG* 02 39 31.5212133624 -34 23 05.395380288     18.534   17.05 ~ 12 0
72 2MASS J02393189-3429201 RG* 02 39 31.8813950832 -34 29 20.159436912   19.988 18.509 17.637 16.94 ~ 14 0
73 2MASS J02393297-3432061 RG* 02 39 32.9670178104 -34 32 06.231358968   19.898 18.42 17.651 17 ~ 11 0
74 2MASS J02393340-3433584 RG* 02 39 33.4102339152 -34 33 58.488301116     18.15   16.76 ~ 11 0
75 GB07 Fnx21 RG* 02 39 34.1141539800 -34 33 09.701904456     18.641   17.01 ~ 10 0
76 GB07 Fnx32 RG* 02 39 38.0933137368 -34 37 06.310980516     18.494   17.07 ~ 9 0
77 2MASS J02393846-3426107 RG* 02 39 38.4515419752 -34 26 10.752918144     18.54   17.07 ~ 9 0
78 GB07 Fnx24 RG* 02 39 41.8146092952 -34 34 16.562844768     18.633     ~ 6 0
79 GB07 Fnx14 RG* 02 39 41.9495101800 -34 30 36.019343448     18.488   16.84 ~ 9 0
80 GB07 Fnx36 RG* 02 39 43.0954599408 -34 40 18.653395836     18.641   17.05 ~ 9 0
81 [LHT2010] BL227 RG* 02 39 45.2751806495 -34 31 57.867250727           ~ 10 0
82 2MASS J02394711-3431499 RG* 02 39 47.1107180904 -34 31 49.878417792   20.269 18.59 17.746   ~ 11 0
83 2MASS J02394972-3428506 RG* 02 39 49.7023803432 -34 28 50.637389844   20.188 18.6 17.813 17.06 ~ 10 0
84 2MASS J02395065-3426474 RG* 02 39 50.6642553312 -34 26 47.444004096   20.088 18.39 17.658 16.91 ~ 13 0
85 WEL 60 RG* 02 39 50.7986837496 -34 28 36.829639848     18.53     K5 8 0
86 [MOW91] 16 RG* 02 39 51.2172969288 -34 29 58.867178388   20.20 18.57   16.74 ~ 12 0
87 GB07 Fnx02 RG* 02 39 51.4491689640 -34 21 21.107522736   20.63 18.548     ~ 10 0
88 [LHT2010] BL233 RG* 02 39 53.6139290592 -34 37 50.154236911           ~ 6 0
89 2MASS J02395387-3429567 RG* 02 39 53.8678292952 -34 29 56.558760360   20.47 18.29   16.70 ~ 9 0
90 GB07 Fnx27 RG* 02 39 54.2656046933 -34 35 11.337835496     18.592     ~ 5 0
91 [KGS2010] For 64059 RG* 02 39 55.4015132472 -34 29 54.846116256   20.214   17.719   ~ 10 0
92 [WMO2009] For-1233 * 02 39 56.0375212872 -34 24 10.603664676     18.46   16.98 ~ 8 0
93 [KGS2010] For 66101 RG* 02 39 57.3255133560 -34 31 21.002452428   20.153   17.674   ~ 9 0
94 [LHT2010] BL261 RG* 02 39 57.8196153297 -34 26 49.235647056           ~ 9 0
95 [WMO2009] For-2280 RR* 02 39 58.2312601848 -34 32 05.319000816   20.109 18.43 17.616 16.9 ~ 16 0
96 MCG-06-07-001 G 02 39 59.3 -34 26 57   9.02 7.4     ~ 1894 1
97 WEL 112 RG* 02 40 04.4134239600 -34 27 11.601236808   19.946 18.37 17.414   K5 17 0
98 2MASS J02400616-3428523 RG* 02 40 06.1711456656 -34 28 52.205077164   20.114 18.379 17.526 16.787 ~ 8 0
99 2MASS J02400753-3423320 RG* 02 40 07.5419948856 -34 23 31.992389592     18.42   16.99 ~ 10 0
100 2MASS J02401001-3429589 RG* 02 40 10.0211800872 -34 29 58.971068232   19.76 18.2 18.060 16.75 ~ 17 0
101 [WMO2009] For-1255 RG* 02 40 10.4430216624 -34 25 17.664484152     18.45   16.81 ~ 10 0
102 2MASS J02401350-3430022 RG* 02 40 13.5116506728 -34 30 02.158265376   19.880   17.646   ~ 7 0
103 [WMO2009] For-1250 RG* 02 40 16.7867669616 -34 29 34.568503332   20.082 18.39 17.547 16.75 ~ 14 0
104 GB07 Fnx07 RG* 02 40 17.5320786384 -34 26 06.568309572     18.180   16.76 ~ 9 0
105 [WMO2009] For-2044 RG* 02 40 17.9251606224 -34 27 01.042993260     18.42   16.79 ~ 12 0
106 2MASS J02402046-3424003 RG* 02 40 20.4704009928 -34 24 00.376747020     18.37   16.73 ~ 11 0
107 [LHT2010] BL311 RG* 02 40 22.6661213808 -34 31 31.198266228           ~ 9 0
108 2MASS J02402422-3426205 RG* 02 40 24.2493531072 -34 26 20.369868324   19.872 18.41 17.709 17.04 ~ 9 0
109 NAME Reticulum II G 03 35 42.1 -54 02 57           ~ 375 0
110 LAMOST J112456.61+453531.3 * 11 24 56.6106775656 +45 35 31.306337916           ~ 13 0
111 GrW 170817 GWE 13 09 48.0850 -23 22 53.343           ~ 2683 0
112 Z 318-18 G 15 09 08.0 +67 13 21   13.60 10.6     ~ 1459 0
113 2MASS J15095862+6716200 RB? 15 09 58.6103318448 +67 16 20.032584024   18.53 17.006   15.614 ~ 41 0
114 2MASS J18174532-3353235 RG* 18 17 45.3298477536 -33 53 23.569406016     13.957 13.63   ~ 12 0
115 HD 222925 Pe* 23 45 17.6074777008 -61 54 42.835286016   9.56 9.03     ApSrEu 83 0
116 NAME Local Group GrG ~ ~           ~ 9325 0

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