2021A&A...647A.134B


Query : 2021A&A...647A.134B

2021A&A...647A.134B - Astronomy and Astrophysics, volume 647A, 134-134 (2021/3-1)

Massive stars in the Small Magellanic Cloud. Evolution, rotation, and surface abundances.

BOURET J.-C., MARTINS F., HILLIER D.J., MARCOLINO W.L.F., ROCHA-PINTO H.J., GEORGY C., LANZ T. and HUBENY I.

Abstract (from CDS):


Context. The evolution of massive stars depends on several physical processes and parameters. Metallicity and rotation are among the most important, but their quantitative effects are not well understood.
Aims. To complement our earlier study on main-sequence stars, we study the evolutionary and physical properties of evolved O stars in the Small Magellanic Cloud (SMC). We focus in particular on their surface abundances to further investigate the efficiency of rotational mixing as a function of age, rotation, and global metallicity.
Methods. We analysed the UV and optical spectra of 13 SMC O-type giants and supergiants using the stellar atmosphere codeCMFGEN to derive photospheric and wind properties. We compared the inferred properties to theoretical predictions from evolution models. For a more comprehensive analysis, we interpret the results together with those we previously obtained for O-type dwarfs.
Results. Most dwarfs of our sample lie in the early phases of the main sequence. For a given initial mass, giants are farther along the evolutionary tracks, which confirms that they are indeed more evolved than dwarfs. Supergiants have higher initial masses and are located past the terminal-age main-sequence in each diagram. We find no clear trend of a mass discrepancy, regardless of the diagram that was used to estimate the evolutionary mass. Surface CNO abundances are consistent with nucleosynthesis from the CNO cycle. Comparisons to theoretical predictions reveal that the initial mixture is important when the observed trends in the N/C versus N/O diagram are to be reproduced. A trend for stronger chemical evolution for more evolved objects is observed. Above about 30M, more massive stars are on average more chemically enriched at a given evolutionary phase. Below 30M, the trend vanishes. This is qualitatively consistent with evolutionary models. A principal component analysis of the abundance ratios for the whole (dwarfs and evolved stars) sample supports the theoretical prediction that massive stars at low metallicity are more chemically processed than their Galactic counterparts. Finally, models including rotation generally reproduce the surface abundances and rotation rates when different initial rotational velocities are considered. Nevertheless, for some objects, a stronger braking and/or more efficient mixing is required.

Abstract Copyright: © J.-C. Bouret et al. 2021

Journal keyword(s): stars: early-type - stars: massive - stars: abundances - stars: fundamental parameters - stars: rotation - Magellanic Clouds

CDS comments: Star N66 not identified.

Simbad objects: 43

goto Full paper

goto View the references in ADS

Number of rows : 43
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 SK 10 s*b 00 46 42.1591125672 -73 24 55.494317340 11.903 12.984 13.176   13.35 O6.5I(f) 47 0
2 AzV 43 * 00 48 47.8983993528 -72 46 24.890763828   13.76 13.88     O9II 19 0
3 AzV 47 * 00 48 51.4911440520 -73 25 58.537753356 12.263 13.314 13.496   14.00 O8III 36 0
4 BBB SMC 1 * 00 50 17.2067283312 -72 53 30.259838832 12.093 13.144 13.326 13.39 13.47 OC7.5III((f)) 44 0
5 LIN 156 s*b 00 50 32.4050818488 -72 52 36.441355908 11.553 12.604 12.756   12.89 O5.5I(f) 51 0
6 AzV 77 * 00 50 33.5144777088 -72 47 45.008016756 12.74 13.79 13.95   14.12 O7III 10 0
7 AzV 83 s*b 00 50 52.0015192368 -72 42 14.940550980 12.233 13.244 13.366   13.67 O7Iaf+ 47 0
8 AzV 95 * 00 51 21.6002057448 -72 44 14.875230300 12.67 13.64 13.83   13.95 O7III((f)) 41 0
9 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 11286 1
10 AzV 148 * 00 53 42.2323318536 -72 42 35.278898580 12.99 13.97 14.16   14.33 B0 13 0
11 AzV 170 s*b 00 55 42.4299731736 -73 17 30.523500780 12.86 13.82 14.11   14.25 O9.7I 32 0
12 AzV 177 * 00 56 44.1036082560 -72 03 31.678578504 13.22 14.39 14.62   14.90 O4Vz 26 0
13 AzV 189 * 00 57 32.5145162232 -72 28 51.133365372 13.29 14.34 14.47   14.67 B0(IV) 11 0
14 Cl* NGC 346 MPG 12 * 00 58 14.0865065520 -72 10 44.292892764   19.15 17.98   16.72 B0IV(Nstr) 32 0
15 Cl* NGC 346 ELS 28 * 00 58 31.7543622456 -72 10 57.965696544 13.58 14.73 14.94   15.23 OC6Vz 27 0
16 Cl* NGC 346 ELS 50 * 00 58 55.2212724984 -72 09 06.692331348 14.07 15.24 15.49   15.80 O8Vn 12 0
17 Cl* NGC 346 ELS 7 * 00 58 57.3961905528 -72 10 33.660822720 12.68 13.82 14.13   14.28 O4V((f+)) 52 0
18 Cl* NGC 346 W 3 * 00 59 00.7591806336 -72 10 28.171806492 11.46 12.61 12.80   13.63 O2III(f) 62 0
19 Cl* NGC 346 NMC 34 * 00 59 00.9631326096 -72 11 09.278888748 14.11 15.20 15.46   15.57 O6.5V 12 0
20 Cl* NGC 346 NMC 28 * 00 59 01.8187292184 -72 10 31.216864152   13.95 14.18     O5.5V((f+)) 31 0
21 NGC 346 Cl* 00 59 04.4000 -72 10 39.000           ~ 496 0
22 Cl* NGC 346 NMC 17 * 00 59 06.7498587648 -72 10 41.262204828 13.05 14.19 14.33   14.60 O8V 21 0
23 Cl* NGC 346 ELS 51 * 00 59 08.6965433496 -72 10 14.136149136 14.03 15.17 15.40   15.62 O7Vz 15 0
24 Cl* NGC 346 ELS 22 * 00 59 18.6176208672 -72 11 09.887619084   14.65 14.91     O9V 20 0
25 Cl* NGC 346 ELS 46 Y*O 00 59 31.8683861040 -72 13 35.225231592   15.16 15.44     O7Vn 13 0
26 SK 80 s*b 00 59 31.9751731656 -72 10 46.106730444   12.12 12.31     O7Iaf+ 108 0
27 Cl* NGC 346 ELS 31 * 00 59 54.0614692656 -72 04 31.420184880 13.71 14.81 15.05   15.33 O8Vz 19 0
28 SK 84 * 01 00 06.7253852112 -72 47 19.124459916 12.58 13.71 13.91   14.16 O6V 44 0
29 AzV 267 * 01 01 15.6926628168 -72 06 35.367953616   14.58 14.84     O7.5-8V 18 0
30 AzV 304 * 01 02 21.4823289456 -72 39 14.587308576   14.66 14.77     B0.5V 48 0
31 AzV 307 * 01 02 32.1812082792 -72 39 42.569272548 13.34 13.88 14.02   14.26 O9III 11 0
32 AzV 326 * 01 03 09.308 -72 25 56.69   13.84 13.92 14.07 14.40 B0(IV) 12 0
33 RMC 28 s*b 01 03 10.5480205584 -72 02 14.335031256 11.833 12.924 13.086   13.60 O9.7I 41 0
34 NAME SMC Bar PoG 01 05 -72.6           ~ 236 0
35 AzV 388 * 01 05 39.5306276568 -72 29 26.938329540 12.79 13.86 14.12   14.37 O5V 42 0
36 AzV 429 EB* 01 07 59.8335369624 -72 00 53.979262812 13.40 14.49 14.69   14.91 O7Vz 20 0
37 AzV 439 * 01 08 51.0869885112 -71 49 51.681780912 13.47 14.49 14.68   14.87 O9.5III 16 0
38 AzV 446 * 01 09 25.4274489696 -73 09 29.906782668 13.37 14.38 14.61   14.91 O6.5Vz 22 0
39 AzV 461 * 01 11 25.5705843312 -72 09 48.802253292 13.22 14.40 14.61   14.94 O8V+neb 20 0
40 AzV 468 * 01 12 05.8755103152 -72 40 56.600864328 13.83 14.86 15.14   15.49 O8.5V 15 0
41 NAME Magellanic Clouds GrG 03 00 -71.0           ~ 7177 0
42 NAME Chandra Deep Field-South reg 03 32 28.0 -27 48 30           ~ 2109 1
43 NAME LMC G 05 23 34.6 -69 45 22     0.4     ~ 17639 0

To bookmark this query, right click on this link: simbad:objects in 2021A&A...647A.134B and select 'bookmark this link' or equivalent in the popup menu