Chemical Analysis of Five Red Giants in the Globular Cluster M10 (NGC 6254)

Haynes, Sharina; Burks, G. S.; Johnson, Christian I.; Pilachowski, Catherine A.

doi:10.1086/592717

Cited by 4 publications

(1 citation statement)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here we present a multi-wavelength study of a radioselected black hole candidate in the Galactic globular cluster M10 (NGC 6254; D = 4.4 kpc; Hurley et al 1989;Harris 1996Harris (2010). M10 has a [Fe/H] ∼ −1.5, and its mass is about 1.5 ×10 5 M (McLaughlin & van der Marel 2005;Haynes et al 2008). In Section 2, we discuss our VLA observations, Chandra X-ray data, Hubble Space Telescope optical photometry, and ground-based SOAR spectroscopy of the system.…”

Section: Introductionmentioning

confidence: 99%

The MAVERIC Survey: A Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10

Shishkovsky¹,

Strader²,

Chomiuk³

et al. 2018

ApJ

View full text Add to dashboard Cite

We present the discovery and characterization of a radio-bright binary in the Galactic globular cluster M10. First identified in deep radio continuum data from the Karl G. Jansky Very Large Array, M10-VLA1 has a flux density of 27 ± 4 µJy at 7.4 GHz and a flat to inverted radio spectrum. Chandra imaging shows an X-ray source with L X ≈ 10 31 erg s −1 matching the location of the radio source. This places M10-VLA1 within the scatter of the radio-X-ray luminosity correlation for quiescent stellarmass black holes, and a black hole X-ray binary is a viable explanation for this system. The radio and X-ray properties of the source disfavor, though do not rule out, identification as an accreting neutron star or white dwarf system. Optical imaging from the Hubble Space Telescope and spectroscopy from the SOAR telescope show the system has an orbital period of 3.339 d and an unusual "red straggler" component: an evolved star found redward of M10's red giant branch. These data also show UV/optical variability and double-peaked Hα emission characteristic of an accretion disk. However, SOAR spectroscopic monitoring reveals that the velocity semi-amplitude of the red straggler is low. We conclude that M10-VLA1 is most likely either a quiescent black hole X-ray binary with a rather face-on (i < 4 • ) orientation or an unusual flaring RS CVn-type active binary, and discuss future observations that could distinguish between these possibilities.

show abstract

Section: Introductionmentioning

confidence: 99%

The MAVERIC Survey: A Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10

Shishkovsky¹,

Strader²,

Chomiuk³

et al. 2018

ApJ

View full text Add to dashboard Cite

show abstract

All quiet in the outer halo: chemical abundances in the globular cluster Pal 3

Koch¹,

Côté

McWilliam

2009

A&A

View full text Add to dashboard Cite

Context. Globular clusters (GCs) in the outer halo are important probes of the composition and origin of the Galactic stellar halo. Aims. We derive chemical element abundance ratios in red giants belonging to the remote (R ∼90 kpc) GC Pal 3 and compare our measurements to those for red giant stars in both inner and outer halo GCs. Methods. From high-resolution spectroscopy of four red giants, obtained with the Magellan/MIKE spectrograph at moderately high S/N, we derive chemical abundances for 25 α-, iron peak-, and neutron-capture elements. These abundance ratios are confirmed by co-adding low S/N HIRES spectra of 19 stars along the red giant branch. Results. Pal 3 shows α-enhanced abundance patterns, and also its Fe-peak and neutron-capture element ratios, are fully compatible with those found in halo field stars and representative inner halo GCs of the same metallicity (such as M 13). The heavy elements in Pal 3 appear to be governed by r-process nucleosynthesis. Our limited sample does not show any significant star-to-star abundance variations in this cluster, although a weak Na-O anti-correlation cannot be ruled out by the present data. Conclusions. Pal 3 thus appears as an archetypical GC with abundance ratios dissimilar to dwarf spheroidal stars, ruling out a direct connection to such external systems. This conclusion is underscored by the lack of significant abundance spreads in this GC, in contrast to the broad abundance distributions seen in the dwarf galaxies. Pal 3 appears to have evolved chemically coeval with the majority of GCs belonging to the Galactic inner and outer halo, experiencing a similar enrichment history.

show abstract

Constraining Stellar Population Models. I. Age, Metallicity and Abundance Pattern Compilation for Galactic Globular Clusters

Roediger

Courteau

Graves

et al. 2013

ApJS

View full text Add to dashboard Cite

We present an extenstive literature compilation of age, metallicity, and chemical abundance pattern information for the 41 Galactic globular clusters (GGCs) studied by Schiavon et al. (2005). Our compilation constitutes a notable improvement over previous similar work, particularly in terms of chemical abundances. Its primary purpose is to enable detailed evaluations of and refinements to stellar population synthesis models designed to recover the above information for unresolved stellar systems based on their integrated spectra. However, since the Schiavon sample spans a wide range of the known GGC parameter space, our compilation may also benefit investigations related to a variety of astrophysical endeavours, such as the early formation of the Milky Way, the chemical evolution of GGCs, and stellar evolution and nucleosynthesis. For instance, we confirm with our compiled data that the GGC system has a bimodal metallicity distribution and is uniformly enhanced in the α-elements. When paired with the

show abstract

Chemical Analysis of Five Red Giants in the Globular Cluster M10 (NGC 6254)

Cited by 4 publications

References 33 publications

The MAVERIC Survey: A Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10

The MAVERIC Survey: A Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10

All quiet in the outer halo: chemical abundances in the globular cluster Pal 3

Constraining Stellar Population Models. I. Age, Metallicity and Abundance Pattern Compilation for Galactic Globular Clusters

Contact Info

Product

Resources

About