Infrared Period-Luminosity Relations of Evolved Variable Stars in the Large Magellanic Cloud

Riebel, D.; Meixner, Margaret; Fraser, Oliver J.; Srinivasan, S.; Cook, K. H.; Vijh, U.

doi:10.1088/0004-637x/723/2/1195

Cited by 78 publications

(121 citation statements)

References 38 publications

Supporting

Mentioning

116

Contrasting

Order By: Relevance

“…It is remarkable that two of our CEMP stars (HE 1410+0213 and HE 0017+0055) appear to exhibit near-periodic lowamplitude velocity variations of periods similar to those identified by Riebel et al (2010) in the large Optical Gravitational Lensing Experiment (OGLE) data set of pulsating Large Magellanic Cloud (LMC) giants and C-rich AGB stars. Signatures of similar pulsations in another two CEMP stars are found in the sample of Jorissen et al (2016b), but not among carbon-normal VMP/EMP r-process-enhanced stars.…”

Section: The Apparently Single Starssupporting

confidence: 53%

The role of binaries in the enrichment of the early Galactic halo

Hansen

Andersen

Nordström

et al. 2016

A&A

142

146

View full text Add to dashboard Cite

Context. Detailed spectroscopic studies of metal-poor halo stars have highlighted the important role of carbon-enhanced metal-poor (CEMP) stars in understanding the early production and ejection of carbon in the Galaxy and in identifying the progenitors of the CEMP stars among the first stars formed after the Big Bang. Recent work has also classified the CEMP stars by absolute carbon abundance, A(C), into high-and low-C bands, mostly populated by binary and single stars, respectively. Aims. Our aim is to determine the frequency and orbital parameters of binary systems among the CEMP-s stars, which exhibit strong enhancements of neutron-capture elements associated with the s-process. This allows us to test whether local mass transfer from a binary companion is necessary and sufficient to explain their dramatic carbon excesses. Methods. We have systematically monitored the radial velocities of a sample of 22 CEMP-s stars for several years with ∼monthly, high-resolution, low S/N échelle spectra obtained at the Nordic Optical Telescope (NOT) at La Palma, Spain. From these spectra, radial velocities with an accuracy of ≈100 m s −1 were determined by cross-correlation with optimised templates. Results. Eighteen of the 22 stars exhibit clear orbital motion, yielding a binary frequency of 82 ± 10%, while four stars appear to be single (18 ± 10%). We thus confirm that the binary frequency of CEMP-s stars is much higher than for normal metal-poor giants, but not 100% as previously claimed. Secure orbits are determined for eleven of the binaries and provisional orbits for six long-period systems (P > 3000 days), and orbital circularisation timescales are discussed. Conclusions. The conventional scenario of local mass transfer from a former asymptotic giant branch (AGB) binary companion does appear to account for the chemical composition of most CEMP-s stars. However, the excess of C and s-process elements in some single CEMP-s stars was apparently transferred to their natal clouds by an external (distant) source. This finding has important implications for our understanding of carbon enrichment in the early Galactic halo and some high-redshift damped lyman alpha (DLA) systems, and of the mass loss from extremely metal-poor AGB stars.

show abstract

Section: The Apparently Single Starssupporting

confidence: 53%

The role of binaries in the enrichment of the early Galactic halo

Hansen

Andersen

Nordström

et al. 2016

A&A

142

146

View full text Add to dashboard Cite

show abstract

“…For example, such comparisons have allowed primarily to estimate the extension of the third dredge-up (hereinafter TDU), i.e. the inwards penetration of the bottom of the convective envelope in the phase following each thermal pulse (Izzard et al 2004;Girardi & Marigo 2007;Groenewegen et al 2007;Riebel et al 2010Riebel et al , 2012Srinivasan et al 2009Srinivasan et al , 2011Boyer et al 2011Boyer et al , 2012. More recent studies were focused on the dust production by AGB stars in the MC and the characterisation of the most obscured sources (Dell'Agli et al 2014, 2015aVentura et al 2015.…”

Section: Introductionmentioning

confidence: 99%

Planetary nebulae in the Small Magellanic Cloud

Ventura

Stanghellini

Criscienzo

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

We analyse the planetary nebulae (PNe) population of the Small Magellanic Cloud (SMC), based on evolutionary models of stars with metallicities in the range 10 −3 ≤ Z ≤ 4 × 10 −3 and mass 0.9 M < M < 8 M , evolved through the asymptotic giant branch (AGB) phase. The models used account for dust formation in the circumstellar envelope. To characterise the PNe sample of the SMC, we compare the observed abundances of the various species with the final chemical composition of the AGB models: this study allows us to identify the progenitors of the PNe observed, in terms of mass and chemical composition. According to our interpretation, most of the PNe descend from low-mass (M < 2M ) stars, which become carbon rich, after experiencing repeated third dredge-up episodes, during the AGB phase. A fraction of the PNe showing the signature of advanced CNO processing are interpreted as the progeny of massive AGB stars, with mass above ∼ 6M , undergoing strong hot bottom burning. The differences with the chemical composition of the PNe population of the Large Magellanic Cloud (LMC) is explained on the basis of the diverse star formation history and age-metallicity relation of the two galaxies. The implications of the present study for some still highly debated points regarding the AGB evolution are also commented.

show abstract

“…Extreme AGB stars clearly produce a large scatter and a mix of population in the sequences. As shown in Riebel et al (2010) and Ita & Matsunaga (2011), the scatter in the period-magnitude relations is smaller when using mid-infrared data. Comparing 2MASS and SAGE data, Riebel et al (2010) showed in (log P, magnitude) diagrams that the sequences are more clearly defined when using the Spitzer [3.6] band.…”

Section: Catalogmentioning

confidence: 85%

Long period variables in the Large Magellanic Cloud from the EROS-2 survey

Spano

Mowlavï

Eyer

et al. 2011

A&A

View full text Add to dashboard Cite

Context. The EROS-2 survey has produced a database of millions of time series from stars monitored for more than six years, allowing us to classify some of their sources into different variable star types. Among the so-called, long period variables (LPVs), which are known to follow particular sequences in the period-luminosity diagram, we find long secondary period variables whose variability origin remains a matter of debate. Aims. We analyze data for the 856 864 variable stars that have been discovered in the Large Magellanic Cloud (LMC) that are present in the EROS-2 database, to detect, classify, and characterize LPVs. Methods. Our method for identifying LPVs is based on the statistical Abbe test. It investigates the regularity of the light curve with respect to the survey duration in order to extract candidates with long-term variability. The period search is performed using Deeming, Lomb-Scargle, and generalized Lomb-Scargle methods, combined with a Fourier series fit. Color−magnitude, period-magnitude, and period-amplitude diagrams are used to characterize our candidates.Results. We present a catalog of 43 551 LPV candidates for the Large Magellanic Cloud. For each of them, we provide up to five periods, a mean magnitude in EROS-2, 2MASS, and Spitzer bands, B E −R E color, R E amplitude, and spectral type. We use infrared data to distinguish between RGB, O-rich, C-rich, and extreme AGB stars. Properties of our LPV candidates are investigated by analyzing period-luminosity and period-amplitude diagrams.

show abstract

Infrared Period-Luminosity Relations of Evolved Variable Stars in the Large Magellanic Cloud

Cited by 78 publications

References 38 publications

The role of binaries in the enrichment of the early Galactic halo

The role of binaries in the enrichment of the early Galactic halo

Planetary nebulae in the Small Magellanic Cloud

Long period variables in the Large Magellanic Cloud from the EROS-2 survey

Contact Info

Product

Resources

About