RUBIDIUM IN THE INTERSTELLAR MEDIUM

Journal Article · Fri Nov 20 04:00:00 EST 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/706/1/614· OSTI ID:21378165

Walker, Kyle M; Federman, S R ^[1]; Knauth, David C ^[2]

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1. Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States)
2. Franklin High School, Reisterstown, MD 21136 (United States)

We present observations of interstellar rubidium toward o Per, zeta Per, AE Aur, HD 147889, chi Oph, zeta Oph, and 20 Aql. Theory suggests that stable {sup 85}Rb and long-lived {sup 87}Rb are produced predominantly by high-mass stars, through a combination of the weak s- and r-processes. The {sup 85}Rb/{sup 87}Rb ratio was determined from measurements of the Rb I line at 7800 A and was compared to the solar system meteoritic ratio of 2.59. Within 1sigma uncertainties, all directions except HD 147889 have Rb isotope ratios consistent with the solar system value. The ratio toward HD 147889 is much lower than the meteoritic value and similar to that toward rho Oph A; both lines of sight probe the Rho Ophiuchus Molecular Cloud. The earlier result was attributed to a deficit of r-processed {sup 85}Rb. Our larger sample suggests instead that {sup 87}Rb is enhanced in these two lines of sight. When the total elemental abundance of Rb is compared to the K elemental abundance, the interstellar Rb/K ratio is significantly lower than the meteoritic ratio for all the sight lines in this study. Available interstellar samples for other s- and r- process elements are used to help interpret these results.

• OSTI ID: 21378165
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 706; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
EVOLUTION
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MASS
NANOSECONDS LIVING RADIOISOTOPES
NUCLEI
ODD-EVEN NUCLEI
R PROCESS
RADIOISOTOPES
RUBIDIUM 85
RUBIDIUM 87
RUBIDIUM ISOTOPES
SOLAR SYSTEM
STABLE ISOTOPES
STAR EVOLUTION
STARS
YEARS LIVING RADIOISOTOPES