J/A+A/658/A80 Red giants of NGC 1851 (Tautvaisiene+, 2022)
Gaia-ESO Survey: Detailed elemental abundances in red giants of the peculiar
globular cluster NGC 1851.
Tautvaisiene G., Drazdauskas A., Bragaglia A., Martell S.L., Pancino E.,
Lardo C., Mikolaitis S., Minkeviciute R., Stonkute E., Ambrosch M.,
Bagdonas V., Chorniy Y., Sanna N., Franciosini E., Smiljanic R., Randich S.,
Gilmore G., Bensby T., Bergemann M., Gonneau A., Guiglion G., Carraro G.,
Heiter U., Korn A., Magrini L., Morbidelli L., Zaggia S.
<Astron. Astrophys. 658, A80 (2022)>
=2022A&A...658A..80T 2022A&A...658A..80T (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Abundances ; Spectroscopy ; Optical
Keywords: stars: abundances - stars: evolution -
globular clusters: individual: NGC 1851
Abstract:
NGC 1851 is one of several globular clusters for which multiple
stellar populations of the subgiant branch have been clearly
identified and a difference in metallicity detected. A crucial piece
of information on the formation history of this cluster can be
provided by the sum of A(C+N+O) abundances. However, these values have
lacked a general consensus thus far. The separation of the subgiant
branch can be based on age and/or A(C+N+O) abundance differences.
Our main aim was to determine carbon, nitrogen, and oxygen abundances
for evolved giants in the globular cluster NGC 1851 in order to check
whether or not the double populations of stars are coeval.
High-resolution spectra, observed with the FLAMES-UVES spectrograph on
the ESO VLT telescope, were analysed using a differential model
atmosphere method. Abundances of carbon were derived using spectral
synthesis of the C 2 band heads at 5135 and 5635.5Å. The wavelength
interval 6470-6490Å, with CN features, was analysed to determine
nitrogen abundances. Oxygen abundances were determined from the [OI]
line at 6300Å. Abundances of other chemical elements were
determined from equivalent widths or spectral syntheses of unblended
spectral lines.
We provide abundances of up to 29 chemical elements for a sample of 45
giants in NGC 1851. The investigated stars can be separated into two
populations with a difference of 0.07dex in the mean metallicity,
0.3dex in the mean C/N, and 0.35 dex in the mean s-process dominated
element-to-iron abundance ratios [s/Fe]. No significant difference was
determined in the mean values of A(C+N+O) as well as in abundance to
iron ratios of carbon, α- and iron-peak-elements, and of europium.
As the averaged A(C+N+O) values between the two populations do not
differ, additional evidence is given that NGC 1851 is composed of two
clusters, the metal-rich cluster being by about 0.6Gyr older than the
metal-poor one. A global overview of NGC 1851 properties and the
detailed abundances of chemical elements favour its formation in a
dwarf spheroidal galaxy that was accreted by the Milky Way.
Description:
Based on data products from observations made with ESO Telescopes at
the La Silla Paranal Observatory under programme ID 188.B-3002 (The
Gaia-ESO Public Spectroscopic Survey, PIs G. Gilmore and S. Randich).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 529 45 Main atmospheric parameters and elemental abundances
in stars of the globular cluster NGC 1851
--------------------------------------------------------------------------------
See also:
J/MNRAS/442/3044 : Photometry and abundances of NGC1851 stars (Marino+, 2014)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Cname CNAME (HHMMSSss+DDMMSSs)
18- 21 I4 K Teff Effective temperature
23- 25 I3 K e_Teff Error of effective temperature
27- 30 F4.2 [cm/s2] logg Stellar surface gravity
32- 35 F4.2 [cm/s2] e_logg Error of stellar surface gravity
37- 41 F5.2 --- [Fe/H] Metallicity
43- 46 F4.2 --- e_[Fe/H] Error of metallicity
48- 51 F4.2 km/s vt Microturbulent velocity
53- 56 F4.2 km/s e_vt Error of microturbulent velocity
58- 62 F5.2 --- [AlI/H] Abundance [AlI/H]
64- 67 F4.2 --- e_[AlI/H] Error on AlI abundance
69 I1 --- o_[AlI/H] Number of AlI lines
71- 75 F5.2 --- [BaII/H] Abundance [BaII/H]
77- 80 F4.2 --- e_[BaII/H] Error on BaII abundance
82 I1 --- o_[BaII/H] Number of BaII lines
84- 88 F5.2 --- [BaII/H]NLTE Abundance [BaII/H]_NLTE
90- 93 F4.2 --- e_[BaII/H]NLTE Error on BaII_NLTE abundance
95 I1 --- o_[BaII/H]NLTE Number of BaII_NLTE lines
97-101 F5.2 --- [C/H] ? Abundance [C/H]
103-106 F4.2 --- e_[C/H] ? Error on C abundance
108 I1 --- o_[C/H] ? Number of C lines
110-114 F5.2 --- [CaI/H] Abundance [CaI/H]
116-119 F4.2 --- e_[CaI/H] Error on CaI abundance
121-122 I2 --- o_[CaI/H] Number of CaI lines
124-128 F5.2 --- [CaII/H] Abundance [CaII/H]
130-133 F4.2 --- e_[CaII/H] Error on CaII abundance
135 I1 --- o_[CaII/H] Number of CaII lines
137-141 F5.2 --- [CeII/H] Abundance [CeII/H]
143-146 F4.2 --- e_[CeII/H] Error on CeII abundance
148 I1 --- o_[CeII/H] Number of CeII lines
150-154 F5.2 --- [CoI/H] Abundance [CoI/H]
156-159 F4.2 --- e_[CoI/H] Error on CoI abundance
161-162 I2 --- o_[CoI/H] Number of CoI lines
164-168 F5.2 --- [CrI/H] Abundance [CrI/H]
170-173 F4.2 --- e_[CrI/H] Error on CrI abundance
175-176 I2 --- o_[CrI/H] Number of CrI lines
178-182 F5.2 --- [CrII/H] Abundance [CrII/H]
184-187 F4.2 --- e_[CrII/H] Error on CrII abundance
189-190 I2 --- o_[CrII/H] Number of CrII lines
192-196 F5.2 --- [CuI/H] Abundance [CuI/H]
198-201 F4.2 --- e_[CuI/H] Error on CuI abundance
203 I1 --- o_[CuI/H] Number of CuI lines
205-209 F5.2 --- [EuII/H] Abundance [EuII/H]
211-214 F4.2 --- e_[EuII/H] Error on EuII abundance
216 I1 --- o_[EuII/H] Number of EuII lines
218-222 F5.2 --- [LaII/H] ? Abundance [LaII/H]
224-227 F4.2 --- e_[LaII/H] ? Error on LaII abundance
229 I1 --- o_[LaII/H] ? Number of LaII lines
231-235 F5.2 --- A(LiI) ? A(LiI) abundance
237-240 F4.2 --- e_A(LiI) ? Error on A(LiI) abundance
242 I1 --- o_A(LiI) ? Number of LiI lines
244-248 F5.2 --- A(LiI)3DNLTE ? A(LiI)_3DNLTE abundance
250-253 F4.2 --- e_A(LiI)3DNLTE ? Error on A(LiI)_3DNLTE abundance
255 I1 --- o_A(LiI)3DNLTE ? Number of LiI lines
257-261 F5.2 --- [MgI/H] Abundance [MgI/H]
263-266 F4.2 --- e_[MgI/H] Error on MgI abundance
268 I1 --- o_[MgI/H] Number of MgI lines
270-274 F5.2 --- [MnI/H] Abundance [MnI/H]
276-279 F4.2 --- e_[MnI/H] Error on MnI abundance
281-282 I2 --- o_[MnI/H] Number of MnI lines
284-288 F5.2 --- [MoI/H] ? Abundance [MoI/H]
290-293 F4.2 --- e_[MoI/H] ? Error on MoI abundance
295 I1 --- o_[MoI/H] ? Number of MoI lines
297-301 F5.2 --- [N/H] ? Abundance [N/H]
303-306 F4.2 --- e_[N/H] ? Error on N abundance
308 I1 --- o_[N/H] ? Number of N lines
310-314 F5.2 --- [NaI/H] Abundance [NaI/H]
316-319 F4.2 --- e_[NaI/H] Error on NaI abundance
321 I1 --- o_[NaI/H] Number of NaI lines
323-327 F5.2 --- [NaI/H]NLTE ? Abundance [NaI/H]_NLTE
329-332 F4.2 --- e_[NaI/H]NLTE ? Error on NaI_NLTE abundance
334 I1 --- o_[NaI/H]NLTE ? Number of NaI_NLTE lines
336-340 F5.2 --- [NdII/H] Abundance [NdII/H]
342-345 F4.2 --- e_[NdII/H] Error on NdII abundance
347-348 I2 --- o_[NdII/H] Number of NdII lines
350-354 F5.2 --- [NiI/H] Abundance [NiI/H]
356-359 F4.2 --- e_[NiI/H] Error on NiI abundance
361-362 I2 --- o_[NiI/H] Number of NiI lines
364-368 F5.2 --- [OI/H] ? Abundance [OI/H]
370-373 F4.2 --- e_[OI/H] ? Error on OI abundance
375 I1 --- o_[OI/H] ? Number of OI lines
377-381 F5.2 --- [PrII/H] ? Abundance [PrII/H]
383-386 F4.2 --- e_[PrII/H] ? Error on PrII abundance
388 I1 --- o_[PrII/H] ? Number of PrII lines
390-394 F5.2 --- [ScI/H] Abundance [ScI/H]
396-399 F4.2 --- e_[ScI/H] Error on ScI abundance
401 I1 --- o_[ScI/H] Number of ScI lines
403-407 F5.2 --- [ScII/H] Abundance [ScII/H]
409-412 F4.2 --- e_[ScII/H] Error on ScII abundance
414-415 I2 --- o_[ScII/H] Number of ScII lines
417-421 F5.2 --- [SiI/H] Abundance [SiI/H]
423-426 F4.2 --- e_[SiI/H] Error on SiI abundance
428 I1 --- o_[SiI/H] Number of SiI lines
430-434 F5.2 --- [SmII/H] ? Abundance [SmII/H]
436-439 F4.2 --- e_[SmII/H] ? Error on SmII abundance
441 I1 --- o_[SmII/H] ? Number of SmII lines
443-447 F5.2 --- [TiI/H] Abundance [TiI/H]
449-452 F4.2 --- e_[TiI/H] Error on TiI abundance
454-455 I2 --- o_[TiI/H] Number of TiI lines
457-461 F5.2 --- [TiII/H] Abundance [TiII/H]
463-466 F4.2 --- e_[TiII/H] Error on TiII abundance
468-469 I2 --- o_[TiII/H] Number of TiII lines
471-475 F5.2 --- [VI/H] Abundance [VI/H]
477-480 F4.2 --- e_[VI/H] Error on VI abundance
482-483 I2 --- o_[VI/H] Number of VI lines
485-489 F5.2 --- [YII/H] Abundance [YII/H]
491-494 F4.2 --- e_[YII/H] Error on YII abundance
496-497 I2 --- o_[YII/H] Number of YII lines
499-503 F5.2 --- [ZnI/H] Abundance [ZnI/H]
505-508 F4.2 --- e_[ZnI/H] Error on ZnI abundance
510 I1 --- o_[ZnI/H] Number of ZnI lines
512-516 F5.2 --- [ZrI/H] ? Abundance [ZrI/H]
518-521 F4.2 --- e_[ZrI/H] ? Error on ZrI abundance
523-524 I2 --- o_[ZrI/H] ? Number of ZrI lines
526-529 F4.2 --- C/N ? C/N ratio
--------------------------------------------------------------------------------
History:
From Grazina Tautvaisiene, grazina.tautvaisiene(at)tfai.vu.lt
Acknowledgements:
Based on the Gaia-ESO Public Spectroscopic Survey data products from
observations made with the ESO Very Large Telescope at the La Silla
Paranal Observatory under programme ID 188.B-3002. These data products
have been processed by the Cambridge Astronomy Survey Unit (CASU) at
the Institute of Astronomy, University of Cambridge, and the
FLAMES/UVES reduction team at INAF/Osservatorio Astrofisico di
Arcetri. The Gaia-ESO Survey Data Archive is prepared and hosted by
the Wide Field Astronomy Unit, Institute for Astronomy, University of
Edinburgh, which is funded by the UK Science and Technology Facilities
Council. The anonymous referee is thanked for helpful suggestions.
S.L.M acknowledges support from the Australian Research Council
through grant DP180101791 and from the UNSW Scientia Fellowship
program. T.B. was funded by grant No. 2018-04857 from The Swedish
Research Council. U.H. acknowledges support from the Swedish National
Space Agency (SNSA/Rymdstyrelsen). This research has made use of
SIMBAD (operated at CDS, Strasbourg), of VALD (Kupka et al. 2000), and
of NASA's Astrophysics Data System. This work has made use of data
from the European Space Agency (ESA) mission Gaia
(https://www.cosmos.esa.int/gaia), processed by the Gaia Data
Processing and Analysis Consortium (DPAC,
https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the
DPAC has been provided by national institutions, in particular the
institutions participating in the Gaia Multilateral Agreement.
(End) Patricia Vannier [CDS] 19-Nov-2021