2006AJ....132...85P


Query : 2006AJ....132...85P

2006AJ....132...85P - Astron. J., 132, 85-110 (2006/July-0)

Atmospheres, chemical compositions, and evolutionary histories of very metal-poor red horizontal-branch stars in the galactic field and in NGC 7078 (M15).

PRESTON G.W., SNEDEN C., THOMPSON I.B., SHECTMAN S.A. and BURLEY G.S.

Abstract (from CDS):

We have conducted spectrum analyses of 24 field metal-poor ([Fe/H]←2) red horizontal-branch (RHB) stars identified in the HK objective-prism survey and 6 such stars in the globular cluster M15, based on high-quality spectra (R∼40,000, S/N∼100) obtained with the Magellan Inamori Kyocera Echelle spectrograph at the Clay 6.5 m telescope at Las Campanas Observatory. The atmospheric parameters of the RHB stars provide interesting bridges between turnoff stars of similar temperature and red giant branch (RGB) stars of similar gravity, and they permit investigations of abundance trends [X/Fe] versus [Fe/H] in a relatively unexplored region of the temperature-gravity plane. We find that the Teff, logg, vt, and [Fe/H] values determined from our spectra are consistent with expectations from literature spectroscopic studies of other evolved metal-poor stellar classes. We show that the RHB stars have abundance distributions that are consistent with typical halo stars of similar metallicities. The photometric and spectroscopic gravities of the M15 stars differ by amounts that grow with declining temperature. We use a regression derived from these differences to calculate photometric gravities for the field RHB stars. Then we use the locations of the field RHB stars among the evolutionary tracks of Cassisi et al. in the logg versus logTeffplane to estimate their masses and lifetimes as RHB stars. We use these lifetimes to estimate the size of the metal-poor HB population from which they arise. Then, using counts of HB and RGB stars in metal-poor globular clusters, we conclude that the number of metal-poor RGB stars at high latitudes (|b|>30°) brighter than V=15 exceeds those identified in extant objective-prism surveys by more than an order of magnitude. Finally, we deduce the effective temperature of the fundamental red edge of the metal-poor RR Lyrae instability strip, logTeff(FRE)=3.80±0.01, from the interface between the temperature distributions of metal-poor field RHB stars and the RR Lyrae stars of similar [Fe/H] in five metal-poor globular clusters.

Abstract Copyright:

Journal keyword(s): Stars: Abundances - Stars: Evolution - Stars: Horizontal-Branch

VizieR on-line data: <Available at CDS (J/AJ/132/85): objects.dat table5.dat>

Simbad objects: 61

goto Full paper

goto View the references in ADS

Number of rows : 61
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 BPS CS 22882-0001 HB* 00 20 25.2919782216 -31 39 04.069467288   15.22 14.82     ~ 18 0
2 BPS CS 31082-0001 Pe* 01 29 31.1311443552 -16 00 45.495314460 12.527 12.427 11.642 11.189 10.713 CEMP 274 0
3 BPS CS 22958-0083 Pe* 02 15 42.7299428184 -53 59 56.257460160 15.057 15.09 14.44 13.981 13.521 CEMP-no 21 0
4 BPS CS 22968-0001 Pe* 02 57 50.8 -56 51 05   15.13 14.74     ~ 13 0
5 BPS CS 22190-0007 HB* 03 52 21.7998585840 -16 24 32.551543692   14.66 14.20   13.504 ~ 10 0
6 HE 0411-3558 Pe* 04 13 09.0581958168 -35 50 38.815893420   13.33 12.96   12.352 CEMP-mp 23 0
7 BPS CS 22182-0033 Pe* 04 23 10.4797815888 -30 37 04.189503288   15.11 14.67     ~ 12 0
8 BPS CS 22191-0029 HB* 04 47 42.4785898512 -39 07 26.463856944   14.46 14.05     ~ 13 0
9 NGC 2419 GlC 07 38 08.51 +38 52 54.9     10.05     ~ 891 0
10 NGC 4372 GlC 12 25 45.43 -72 39 32.7   10.86 9.85     ~ 288 0
11 M 68 GlC 12 39 27.98 -26 44 38.6     7.96     ~ 948 0
12 NGC 5053 GlC 13 16 27.09 +17 42 00.9     9.96     ~ 589 0
13 HD 115444 Pe* 13 16 42.4590842616 +36 22 52.692135420   9.77 8.97 8.3 7.88 G9V 235 0
14 NGC 5466 GlC 14 05 27.29 +28 32 04.0     9.70     ~ 796 0
15 BPS CS 22883-0037 HB* 14 24 19.4273894400 +11 29 26.058132672   15.28 14.73     ~ 9 0
16 BD+09 3223 HB* 16 33 35.5815849384 +09 06 16.307942544   9.85 9.27     ~ 70 0
17 BPS CS 22878-0121 HB* 16 47 50.0361976176 +11 39 11.349179748   14.53 13.99     ~ 9 0
18 NGC 6287 GlC 17 05 09.4906767360 -22 42 28.099250172   11.49 10.30     ~ 210 0
19 M 92 GlC 17 17 07.39 +43 08 09.4     6.52     ~ 2018 0
20 BD+17 3248 HB* 17 28 14.4690179544 +17 30 35.847574776   10.02 9.34     KIIvw 210 0
21 NGC 6426 GlC 17 44 54.71 +03 10 12.5           ~ 206 0
22 BPS CS 22891-0184 HB* 19 26 12.3252330240 -60 34 06.291163668   14.33 13.83   13.034 ~ 12 0
23 BPS CS 22896-0110 HB* 19 35 48.0058172304 -53 26 16.461598344   14.09 13.56     CEMP-no 14 0
24 V* V2202 Sgr RR* 19 52 43.9189675656 -38 57 52.261264764   15.29 14.52     ~ 10 0
25 HD 195636 PM* 20 32 48.9463898400 -09 21 51.724664928   10.13 9.57     A9(V)(w) 89 0
26 BPS CS 22940-0077 Pe* 20 41 33.7241286936 -59 50 35.206322064   14.66 14.13     ~ 12 0
27 BPS CS 22955-0174 HB* 20 42 05.0417411688 -23 49 12.660515652   14.88 14.38     ~ 14 0
28 BPS CS 22940-0070 RR* 20 42 39.2494423512 -61 40 39.106422552   15.35 14.87     ~ 13 0
29 BPS CS 22879-0103 HB* 20 47 10.1397614064 -37 26 52.506501396   14.79 14.30     ~ 11 0
30 BPS CS 22879-0097 HB* 20 48 46.5523487952 -38 30 49.420518840   14.68 14.22     ~ 12 0
31 BPS CS 22940-0121 HB* 20 55 10.8821892648 -58 00 55.150061220   14.16 14.16     ~ 12 0
32 BPS CS 22898-0043 HB* 21 10 36.7674946056 -21 44 51.797016492   14.49 14.06     ~ 11 0
33 BPS CS 29501-0051 HB* 21 14 40.6179247608 -37 24 51.771638016   14.55 14.02     ~ 14 0
34 NGC 7078 79 * 21 29 44.734 +12 11 32.14   15.92 15.29     ~ 6 0
35 NGC 7078 113 * 21 29 47.7196144560 +12 12 16.752976776   15.01 14.45     ~ 9 0
36 NGC 7078 138 * 21 29 49.4219640696 +12 11 21.892619868   16.29 15.69     ~ 6 0
37 2MASS J21295065+1210485 AB* 21 29 50.65992 +12 10 48.5580   16.23 15.55     ~ 5 0
38 NGC 7078 357 HB* 21 29 55.1938087848 +12 11 43.142066628   15.23 14.70     ~ 9 0
39 NGC 7078 944 * 21 29 56.379 +12 10 29.06   16.44 15.88     ~ 6 0
40 M 15 GlC 21 29 58.33 +12 10 01.2           ~ 3054 0
41 NGC 7078 714 HB* 21 30 00.2782102776 +12 14 25.030306644   15.90 15.20     ~ 13 0
42 NGC 7078 769 PM* 21 30 01.1127542784 +12 07 14.998707948 16.11 16.11 15.53 15.90   ~ 5 0
43 NGC 7078 1075 * 21 30 01.466 +12 10 04.25   16.31 15.81     ~ 5 0
44 NGC 7078 785 * 21 30 01.508 +12 12 28.77   15.81 15.17     ~ 3 0
45 NGC 7078 802 * 21 30 01.7971382088 +12 06 44.234924184   14.35 13.68     ~ 7 0
46 NGC 7078 880 * 21 30 03.2741056248 +12 12 30.477657708   16.34 15.77     ~ 5 0
47 2MASS J21300465+1207404 RG* 21 30 04.6488352920 +12 07 40.425692988   15.89 15.18     ~ 9 0
48 2MASS J21300730+1210506 RG* 21 30 07.3003358040 +12 10 50.637042732   16.02 15.13     ~ 11 0
49 BPS CS 22948-0006 HB* 21 33 17.7082418256 -39 39 42.812637300   15.56 15.07     ~ 11 0
50 M 30 GlC 21 40 22.12 -23 10 47.5     7.10     ~ 992 0
51 BPS CS 22944-0039 HB* 21 45 12.2657800728 -14 41 24.827015472   14.85 14.30     ~ 8 0
52 BPS CS 22951-0077 HB* 21 57 53.2097480688 -43 08 08.217932676   14.11 13.61   12.805 ~ 14 0
53 BPS CS 22881-0039 RR* 22 09 35.4282210936 -40 25 51.181395960   15.52 15.14     ~ 28 0
54 V* TY Gru RR* 22 16 39.4204602572 -39 56 17.947129636   14.64 14.10     ~ 35 0
55 BPS CS 22892-0052 Pe* 22 17 01.6558764360 -16 39 27.051026544   14.03 13.20 13.06 12.19 KIIvw 432 0
56 BPS CS 22886-0043 HB* 22 22 33.7871919696 -10 14 08.990223360   15.18 14.72   13.991 ~ 11 0
57 BPS CS 22875-0029 HB* 22 29 25.0902184752 -38 57 47.453172408   14.08 13.69     ~ 16 0
58 BPS CS 22888-0047 HB* 23 20 19.8570157800 -33 45 46.924229268   15.01 14.61     ~ 16 0
59 HD 221170 Pe* 23 29 28.8087143040 +30 25 57.849303180 9.43 8.74 7.66     CEMP-r 276 0
60 BPS CS 22941-0027 HB* 23 34 58.0940316936 -36 52 05.640027348   14.40 14.05     ~ 11 0
61 BPS CS 22945-0056 HB* 23 53 19.7853950280 -65 29 39.566484132   14.485 14.09     ~ 12 0

To bookmark this query, right click on this link: simbad:objects in 2006AJ....132...85P and select 'bookmark this link' or equivalent in the popup menu


2022.12.08-13:58:53

© Université de Strasbourg/CNRS

    • Contact