2016A&A...593A..10A


C.D.S. - SIMBAD4 rel 1.7 - 2020.05.26CEST22:47:21

2016A&A...593A..10A - Astronomy and Astrophysics, volume 593A, 10-10 (2016/9-1)

Follow-up observations of extremely metal-poor stars identified from SDSS.

AGUADO D.S., ALLENDE PRIETO C., GONZALEZ HERNANDEZ J.I., CARRERA R., REBOLO R., SHETRONE M., LAMBERT D.L. and FERNANDEZ-ALVAR E.

Abstract (from CDS):

Context. The most metal-poor stars in the Milky Way witnessed the early phases of formation of the Galaxy, and have chemical compositions that are close to the pristine mixture from Big Bang nucleosynthesis, polluted by one or few supernovae.
Aims. Only two dozen stars with ([Fe/H]< -4) are known, and they show a wide range of abundance patterns. It is therefore important to enlarge this sample. We present the first results of an effort to identify new extremely metal-poor stars in the Milky Way halo.
Methods. Our targets have been selected from low-resolution spectra obtained as part of the Sloan Digital Sky Survey, and followed-up with medium resolution spectroscopy on the 4.2m William Herschel Telescope and, in a few cases, at high resolution on the 9.2m Hobby-Eberly Telescope. Stellar parameters and the abundances of magnesium, calcium, iron, and strontium have been inferred from the spectra using classical model atmospheres. We have also derived carbon abundances from the G band.
Results. We find consistency between the metallicities estimated from SDSS and those from new data at the level of 0.3dex. The analysis of medium resolution data obtained with ISIS on the WHT allows us to refine the metallicities and in some cases measure other elemental abundances. Our sample contains 11 new metal-poor stars with [Fe/H]< -3.0, one of them with an estimated metallicity of [Fe/H]~-4.0. We also discuss metallicity discrepancies of some stars in common with previous works in the literature. Only one of these stars is found to be C-enhanced at about [C/Fe]~+1, whereas the other metal-poor stars show C abundances at the level of [C/Fe]~+0.45.

Abstract Copyright: © ESO, 2016

Journal keyword(s): stars: abundances - stars: fundamental parameters - stars: Population II - Galaxy: stellar content - Galaxy: halo

Status at CDS:  

Simbad objects: 22

goto Full paper

goto View the reference in ADS

Number of rows : 22

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 SDSS J010505.87+461521.7 * 01 05 05.8746165196 +46 15 21.680940205           ~ 1 0
2 SDSS J014036.21+234458.1 Pe* 01 40 36.2206962306 +23 44 58.204189219   15.6       CEMP-no 31 0
3 SDSS J021958.24-084955.8 Pe* 02 19 58.2485421553 -08 49 55.813539421           ~ 3 0
4 SDSS J040114.71-051259.0 Pe* 04 01 14.7139182856 -05 12 59.008323585           ~ 3 0
5 SDSS J044655.69+113741.2 * 04 46 55.6923989191 +11 37 41.302189418           ~ 1 0
6 SDSS J063055.58+255243.7 Pe* 06 30 55.5710037434 +25 52 43.776622574           ~ 5 0
7 SDSS J075818.26+653907.2 * 07 58 18.2868328771 +65 39 07.022832678           ~ 1 0
8 SDSS J101600.42+172901.1 Pe* 10 16 00.4295094294 +17 29 01.425743191           ~ 2 0
9 UCAC3 215-112497 Pe* 10 29 15.1491308300 +17 29 27.926665478         15.98 ~ 89 0
10 SDSS J120441.38+120111.5 Pe* 12 04 41.3884956228 +12 01 11.515022243           ~ 13 0
11 2MASS J12305523+0005467 Pe* 12 30 55.2495907247 +00 05 46.893484810           ~ 5 0
12 HE 1320+0139 Pe* 13 22 50.6003232115 +01 23 42.949469848   16.72 16.08 15.40   ~ 9 0
13 HE 1327-2326 Pe* 13 30 05.9395582011 -23 41 49.699027289 13.761 14.01 13.55 13.50 12.803 CEMP-no 213 0
14 HE 1523-0901 Pe* 15 26 01.0697794752 -09 11 38.882076152   12.37 11.50 10.476 9.863 CEMP 61 0
15 M 13 GlC 16 41 41.634 +36 27 40.75     5.8     ~ 2000 0
16 SDSS J164234.48+443004.9 * 16 42 34.4866428083 +44 30 04.912014390           ~ 3 0
17 SDSS J165618.30+342523.1 Pe* 16 56 18.3095182031 +34 25 23.050655049           ~ 2 0
18 NAME Gal Center reg 17 45 40.04 -29 00 28.1           ~ 11438 0
19 SDSS J183455.03+421329.0 * 18 34 55.0336283868 +42 13 29.068358134           ~ 2 0
20 BPS CS 30336-0049 Pe* 20 45 23.5332845435 -28 42 35.913048347   14.89 14.03 13.328 12.844 ~ 29 0
21 SDSS J214633.18-003910.2 Pe* 21 46 33.1835109483 -00 39 10.239600928           ~ 4 0
22 SDSS J220646.20-092545.7 Pe* 22 06 46.2046247583 -09 25 45.748775639           ~ 11 0

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2016A&A...593A..10A and select 'bookmark this link' or equivalent in the popup menu


2020.05.26-22:47:21

© Université de Strasbourg/CNRS

    • Contact