The Origin of Runaway Stars

Hoogerwerf, R.; Bruijne, J. H. J. de; Zeeuw, P. T. de

doi:10.1086/317315

Cited by 149 publications

(182 citation statements)

References 17 publications

(13 reference statements)

Supporting

Mentioning

175

Contrasting

Unclassified

Order By: Relevance

“…Limongi & Chieffi 2006;Woosley & Heger 2007) (see summary in appendix of Diehl et al 2006a), formally consistent with our derived 26 Al mass. The most massive star in Upper Sco was presumably a ∼50 M O5-O6 star, which may have exploded as a supernova about 1.5 Myr ago; the pulsar PSR J1932+1059 may be its compact remnant (Hoogerwerf et al 2000;Chatterjee et al 2004). But because of uncertainty of this event and no obvious supernova activity being evident in Sco-Cen less than 1 My ago (which would be seen e.g.…”

Section: Discussionmentioning

confidence: 99%

Radioactive²⁶Al from the Scorpius-Centaurus association

Diehl

Lang

Martin

et al. 2010

A&A

129

View full text Add to dashboard Cite

Context. The Scorpius-Centaurus association is the most-nearby group of massive and young stars. As nuclear-fusion products are ejected by massive stars and supernovae into the surrounding interstellar medium, the search for characteristic γ-rays from radioactivity is one way to probe the history of activity of such nearby massive stars on a My time scale through their nucleosynthesis. 26 Al decays with a radioactivity lifetime τ ∼1 My, 1809 keV γ-rays from its decay can be measured with current γ-ray telescopes. Aims. We aim to identify nucleosynthesis ejecta from the youngest subgroup of Sco-Cen stars, and interpret their location and bulk motion from 26 Al observations with INTEGRAL's γ-ray spectrometer SPI. Methods. Following earlier 26 Al γ-ray mapping with NASA's Compton observatory, we test spatial emission skymaps of 26 Al for a component which could be attributed to ejecta from massive stars in the Scorpius-Centaurus group of stars. Such a model fit of spatial distributions for large-scale and local components is able to discriminate 26 Al emission associated with Scorpius-Centaurus, in spite of the strong underlying nucleosynthesis signal from the Galaxy at large. Results. We find an 26 Al γ-ray signal above 5σ significance, which we associate with the locations of stars of the Sco-Cen group. The observed flux of 6 × 10 −5 ph cm −2 s −1 corresponds to ∼1.1 × 10 −4 M of 26 Al. This traces the nucleosynthesis ejecta of several massive stars within the past several million years. Conclusions. We confirm through direct detection of radioactive 26 Al the recent ejection of massive-star nucleosynthesis products from the Sco-Cen association. Its youngest subgroup in Upper Scorpius appears to dominate 26 Al contributions from this association. Our 26 Al signal can be interpreted as a measure of the age and richness of this youngest subgroup. We also estimate a kinematic imprint of these nearby massive-star ejecta from the bulk motion of 26 Al and compare this to other indications of Scorpius-Centaurus massive-star activity.

show abstract

Section: Discussionmentioning

confidence: 99%

Radioactive²⁶Al from the Scorpius-Centaurus association

Diehl

Lang

Martin

et al. 2010

A&A

129

View full text Add to dashboard Cite

show abstract

“…For each object, a selection of spectra centered on He i λ5876 is shown. The spectra are described in Table A.1. a binary system at an earlier stage in its evolution; in particular, (Hoogerwerf et al 2000; see also van Rensbergen et al 1996) argue that ζ Oph resulted from a supernova kick. Regardless of the evolutionary and dynamical history of this star, it did not reach the level of enrichment seen in ON stars.…”

Section: Binarity and The On Phenomenonmentioning

confidence: 99%

Surface abundances of ON stars

Martins

Simón‐Díaz

Palacios

et al. 2015

A&A

View full text Add to dashboard Cite

Context. Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. Aims. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. Methods. We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars. Results. We show that ON stars are usually rich in helium. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate − on average − faster than normal O stars. Evolutionary models including rotation cannot account for the extreme enrichment observed among ON main sequence stars. Some ON stars are members of binary systems, but others are single stars as indicated by stable radial velocities. Mass transfer is therefore not a simple explanation for the observed chemical properties. Conclusions. We conclude that ON stars show extreme chemical enrichment at their surface, consistent with nucleosynthesis through the CNO cycle. Its origin is not clear at present.

show abstract

“…Recent studies (e.g., Palladino et al 2014) have shown that low-mass F or G stars can also travel with extremely high velocities, often exceeding the local Galactic escape velocity. Thus, stars in a cluster or a binary system can be kicked out by a perturbation of the system, for instance, such as in a threebody encounter or a supernova explosion (e.g., Hoogerwerf et al 2000;Perets 2009;Irrgang et al 2010;Zhang et al 2013). To be more specific, there are several possible formation scenarios for HVSs: (1) interaction of single stars with a central massive black hole (MBH); (2) tidal break-up of binary stars in the vicinity of a MBH; (3) three-body interactions involving single-star encounters with a binary or cluster of MBHs; (4) double detonation of SN Ia with a close system of a rapidly orbiting low-mass compact He star and a massive (∼1−1.2 M ) CO-white dwarf (Geier et al 2015); (5) single-degenerate SN type Ia consisting of a white dwarf and a main-sequence star (Liu et al 2013); (6) binary star disruption in dense interacting regions such as globular clusters or the Galactic bulge or disk; or (7) tidal disruption of dwarf galaxies in the Galaxy (Li et al 2015, and references therein).…”

Section: High-velocity Starsmentioning

confidence: 99%

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Hansen¹,

Rich

Koch

et al. 2016

A&A

View full text Add to dashboard Cite

Low-mass variable high-velocity stars are interesting study cases for many aspects of Galactic structure and evolution. Until recently, the only known high-or hyper-velocity stars were young stars thought to originate from the Galactic center. Wide-area surveys such as APOGEE and BRAVA have found several low-mass stars in the bulge with Galactic rest-frame velocities higher than 350 km s −1 . In this study we present the first abundance analysis of a low-mass RR Lyrae star that is located close to the Galactic bulge, with a space motion of ∼-400 km s −1 . Using medium-resolution spectra, we derived abundances (including upper limits) of 11 elements. These allowed us to chemically tag the star and discuss its origin, although our derived abundances and metallicity, at [Fe/H] = −0.9 dex, do not point toward one unambiguous answer. Based on the chemical tagging, we cannot exclude that it originated in the bulge. However, its retrograde orbit and the derived abundances combined suggest that the star was accelerated from the outskirts of the inner (or even outer) halo during many-body interactions. Other possible origins include the bulge itself, or the star might have been stripped from a stellar cluster or the Sagittarius dwarf galaxy when it merged with the Milky Way.

show abstract

The Origin of Runaway Stars

Cited by 149 publications

References 17 publications

Radioactive²⁶Al from the Scorpius-Centaurus association

Radioactive²⁶Al from the Scorpius-Centaurus association

Surface abundances of ON stars

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Contact Info

Product

Resources

About

The Origin of Runaway Stars

Cited by 149 publications

References 17 publications

Radioactive26Al from the Scorpius-Centaurus association

Radioactive26Al from the Scorpius-Centaurus association

Surface abundances of ON stars

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Contact Info

Product

Resources

About

Radioactive²⁶Al from the Scorpius-Centaurus association

Radioactive²⁶Al from the Scorpius-Centaurus association