J/ApJ/824/L19 Carbon-enhanced metal-poor star BD+44493 EWs (Roederer+, 2016)
Detection of phosphorus, sulphur, and zinc in the carbon-enhanced metal-poor
star BD+44 493.
Roederer I.U., Placco V.M., Beers T.C.
<Astrophys. J., 824, L19-L19 (2016)>
=2016ApJ...824L..19R 2016ApJ...824L..19R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, metal-deficient ; Abundances ; Equivalent widths ;
Spectra, ultraviolet
Keywords: nuclear reactions, nucleosynthesis, abundances; stars: abundances;
stars: individual: BD+44 493
Abstract:
The carbon-enhanced metal-poor star BD+44°493 ([Fe/H]=-3.9) has
been proposed as a candidate second-generation star enriched by metals
from a single Pop III star. We report the first detections of P and S
and the second detection of Zn in any extremely metal-poor
carbon-enhanced star, using new spectra of BD+44493 collected by the
Cosmic Origins Spectrograph on the Hubble Space Telescope. We derive
[P/Fe]=-0.34±0.21, [S/Fe]=+0.07±0.41, and [Zn/Fe]=-0.10±0.24. We
increase by 10-fold the number of SiI lines detected in BD+44493,
yielding [Si/Fe]=+0.15±0.22. The [S/Fe] and [Zn/Fe] ratios exclude
the hypothesis that the abundance pattern in BD+44493 results from
depletion of refractory elements onto dust grains. Comparison with
zero-metallicity supernova (SN) models suggests that the stellar
progenitor that enriched BD+44493 was massive and ejected much less
than 0.07M☉ of 56Ni, characteristic of a faint SN.
Description:
We have obtained new observations of portions of the UV spectrum of
BD+44493 using the Cosmic Origins Spectrograph (COS) on HST
(13000<R<17000) in 2015 Nov 21, 22 and in 2015 Dec 04, 08 and 09.
All observations are associated with data sets LCTQ01010-06010 in the
Mikulski Archive for Space Telescopes (MAST, http://archive.stsci.edu/).
Objects:
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RA (ICRS) DE Designation(s)
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02 26 49.74 +44 57 46.5 BD+44 493 = TYC 2843-1104-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 50 51 Atomic data, equivalent widths, and abundances
derived from individual lines
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See also:
B/hst : HST Archived Exposures Catalog (STScI, 2007)
J/ApJ/817/53 : Fe-group elemental abundance in HD84937 (Sneden+, 2016)
J/ApJS/220/13 : Co I transition probabilities (Lawler+, 2015)
J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)
J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)
J/ApJ/773/33 : Chemical data of BD+44493 metal-poor subgiant (Ito+, 2013)
J/ApJ/750/76 : r-process peaks elements in HD 160617 (Roederer+, 2012)
J/MNRAS/412/843 : SAGA extremely metal-poor stars (Suda+, 2011)
J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Sp Species identifier
7- 13 F7.2 0.1nm lambda [1807.3/2153.1] Wavelength (1)
15- 18 F4.2 eV ExPot [0/2.7] Excitation potential
20- 24 F5.2 [-] log(gf) [-2.3/0.2] Log oscillator strength
26- 29 F4.2 [-] e_log(gf) [0.02/0.3] Uncertainty in log(gf)
31 I1 --- r_log(gf) Reference code for log(gf) (2)
33- 37 F5.1 10-13m EW [17/209]? Equivalent width; milli-Angstroms
39 A1 --- l_log(e) Limit flag on log(e)
41- 45 F5.2 [Sun] log(e) [-0.3/4.3] Log abundance
47- 50 F4.2 [Sun] e_log(e) [0.2/0.9]? Uncertainty in log(e)
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Note (1): Air wavelengths are given for lambda>2000Å and vacuum values below.
Note (2): Reference as follows:
1 = NIST (http://www.nist.gov/pml/data/asd.cfm);
2 = Bergeson & Lawler (1993ApJ...408..382B 1993ApJ...408..382B);
3 = Wood et al. (2014, J/ApJS/211/20);
4 = Fedchak & Lawler (1999ApJ...523..734F 1999ApJ...523..734F);
5 = Roederer & Lawler (2012, J/ApJ/750/76).
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 18-Aug-2016