scholarly journals Near Infrared Photometry of New Galactic Globular Clusters GC 01 and GC 02

2002 ◽  
Vol 207 ◽  
pp. 107-109 ◽  
Author(s):  
J. Borissova ◽  
V. D. Ivanov ◽  
L. Vanzi
Keyword(s):  
Globular Cluster ◽  
Preliminary Report ◽  
Globular Clusters ◽  
Surface Brightness ◽  
Near Infrared ◽  
Infrared Photometry ◽  
Galactic Globular Clusters ◽  
Red Giant ◽  
Best Fit ◽  
Calculated Distance

We present a preliminary report on the first deep near infrared photometry of 2MASS GC 01 and 2MASS GC 02 - new Galactic globular cluster candidates, discovered by the 2MASS. The red giant branch slopes yielded [Fe/H]=-0.42 ± 0.15 dex and [Fe/H]=-0.66 ± 0.17 dex, respectively for GC 01 and GC 02. We estimated the reddening towards GC 01 and GC 02: E(B - V) = 5.36 ± 0.20, and E(B - V) = 4.55 ± 0.17. The calculated distance moduli to the clusters are: (m - M)0 = 13.53 ± 0.27 and (m - M)0 = 14.53 ± 0.31 for GC 01 and GC 02. Our best fit for the radial surface brightness profile of GC 02 yields: lg(rc) = 1.40, lg(rh) = 1.54, lg(rt) = 1.31, and c=1.60. CC 01 is less concentrated: lg(rc) = 1.63, lg(rh) = 1.7, lg(rt) = 1.25, and c=1.41.

scholarly journals WIDE FIELD NEAR-INFRARED PHOTOMETRY OF 12 GALACTIC GLOBULAR CLUSTERS: OBSERVATIONS VERSUS MODELS ON THE RED GIANT BRANCH

2015 ◽  
Vol 150 (6) ◽  
pp. 176 ◽  
Author(s):  
Roger E. Cohen ◽  
Maren Hempel ◽  
Francesco Mauro ◽  
Douglas Geisler ◽  
Javier Alonso-Garcia ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Near Infrared ◽  
Wide Field ◽  
Infrared Photometry ◽  
Galactic Globular Clusters ◽  
Red Giant

The GOTHAM survey: chemical evolution of Milky Way globular clusters

2017 ◽  
Vol 13 (S334) ◽  
pp. 25-28
Author(s):  
Bruno Dias ◽  
Beatriz Barbuy ◽  
Ivo Saviane ◽  
Enrico V. Held ◽  
Gary Da Costa ◽  
...  
Keyword(s):  
Chemical Evolution ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Stellar Population ◽  
Milky Way ◽  
Open Clusters ◽  
Giant Stars ◽  
Globular Cluster System ◽  
Galactic Globular Clusters ◽  
Red Giant

AbstractMilky Way globular clusters are excellent laboratories for stellar population detailed analysis that can be applied to extragalactic environments with the advent of the 40m-class telescopes like the ELT. The globular cluster population traces the early evolution of the Milky Way which is the field of Galactic archaeology. We present our GlObular clusTer Homogeneous Abundance Measurement (GOTHAM) survey. We derived radial velocities, Teff, log(g), [Fe/H], [Mg/Fe] for red giant stars in one third of all Galactic globular clusters that represent well the Milky Way globular cluster system in terms of metallicity, mass, reddening, and distance. Our method is based on low-resolution spectroscopy and is intrinsically reddening free and efficient even for faint stars. Our [Fe/H] determinations agree with high-resolution results to within 0.08 dex. The GOTHAM survey provides a new metallicity scale for Galactic globular clusters with a significant update of metallicities higher than [Fe/H] > -0.7. We show that the trend of [Mg/Fe] with metallicity is not constant as previously found, because now we have more metal-rich clusters. Moreover, peculiar clusters whose [Mg/Fe] does not match Galactic stars for a given metallicity are discussed. We also measured the CaII triplet index for all stars and we show that the different chemical evolution of Milky Way open clusters, field stars, and globular clusters implies different calibrations of calcium triplet to metallicity.

scholarly journals M31 Globular Clusters in the Near-Infrared

2002 ◽  
Vol 207 ◽  
pp. 152-153
Author(s):  
Wolfgang Brandner ◽  
R. Brent Tully ◽  
James N. Heasley
Keyword(s):  
Old Age ◽  
Adaptive Optics ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Near Infrared ◽  
Time Resolved ◽  
Red Giant ◽  
The University ◽  
First Time ◽  
Adaptive Optics System

We have observed the M31 globular clusters with the University of Hawaii Adaptive Optics System Hokupa'a at the Gemini North 8m telescope on Mauna Kea. This is part of a project which aims at spatially resolving intermediate-age and old-age stellar populations in the Local Volume and beyond - possibly out to distances of the Virgo and Fornax clusters. The sparse M31 globular cluster G27 (Hubble 6) is for the first time resolved into individual stars. The tip of the red giant branch (TRGB) at K≈18.8mag yields a metallicity of Z around 0.001 solar for G27.

scholarly journals Abundance of zirconium in the atmospheres of red giants in Galactic globular cluster 47 Tuc

2019 ◽  
Vol 14 (S351) ◽  
pp. 309-311
Author(s):  
Edgaras Kolomiecas ◽  
Vidas Dobrovolskas ◽  
Arūnas Kučinskas
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Stellar Model ◽  
Red Giants ◽  
Line Profiles ◽  
Galactic Field ◽  
Galactic Globular Clusters ◽  
Red Giant

AbstractWe determined zirconium abundance in the atmospheres of 327 red giant branch (RGB) stars in the globular cluster 47 Tuc. The 1D LTE abundances were obtained from the archival VLT GIRAFFE spectra, using 1D hydrostaticATLAS9 stellar model atmospheres and synthetic Zr I line profiles computed with theSYNTHE package. The average zirconium abundance determined in the sample of RGB stars, 〈[Zr/Fe]〉 = +0.38 ± 0.12, agrees well with zirconium abundances obtained at this metallicity in the Galactic field stars, as well as with those observed in other Galactic globular clusters.

scholarly journals Abundance anomalies in globular clusters

1997 ◽  
Vol 189 ◽  
pp. 193-202
Author(s):  
G. S. Da Costa
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
High Density ◽  
Star Forming ◽  
Process Indicators ◽  
Star Forming Regions ◽  
Abundance Anomalies ◽  
Galactic Globular Clusters ◽  
Red Giant

The galactic globular clusters presumably formed rapidly as high density concentrations at the centres of extensive star forming regions and the natural expectation is that they will be chemically homogeneous. In general, this is confirmed by observation — most globular clusters are extremely homogeneous with regard to most elements. (There are two exceptions: ω Cen and M22 both have intrinsic internal abundance ranges. While of considerable interest, e.g. Norris et al. 1996, this type of “abundance anomaly” will not be discussed here). But we have known for more than twenty years that the surface abundances, which are what we observe, of elements such as C, N and O can vary substantially from red giant to red giant within an individual globular cluster. Indeed it has become clear that “abundance anomalies” of this type are common in the galactic globular cluster population. Briefly, the observed anomalies can be summarized as: (i) the “anomalous” stars are depleted in C and enhanced in N. Depletions of O also often accompany the depletions in C. (ii) The C, N and O variations are usually accompanied by enhancements of Na and Al and when the O depletion and the Al enhancement are both large, Mg is depleted. No other elements, including r- and s-process indicators, vary.

scholarly journals Near-Infrared Photometry of Globular Clusters NGC 6287 and NGC 6341 (M92): The Formation of the Galactic Halo

2001 ◽  
Vol 122 (6) ◽  
pp. 3136-3154 ◽  
Author(s):  
Jae-Woo Lee ◽  
Bruce W. Carney ◽  
Laura K. Fullton ◽  
Peter B. Stetson
Keyword(s):  
Globular Clusters ◽  
Near Infrared ◽  
Galactic Halo ◽  
Infrared Photometry

scholarly journals Strömgren and near-infrared photometry of metal-rich bulge globular clusters

2014 ◽  
Vol 565 ◽  
pp. A8 ◽  
Author(s):  
A. Calamida ◽  
G. Bono ◽  
E. P. Lagioia ◽  
A. P. Milone ◽  
M. Fabrizio ◽  
...  
Keyword(s):  
Globular Clusters ◽  
Near Infrared ◽  
Infrared Photometry

scholarly journals Narrow-Band Photometry of Red Variables in Globular Clusters

1973 ◽  
Vol 21 ◽  
pp. 164-177
Author(s):  
Robert F. Wing
Keyword(s):  
Radial Velocity ◽  
Globular Clusters ◽  
Near Infrared ◽  
Narrow Band ◽  
Small Range ◽  
Mira Variables ◽  
Color System ◽  
Red Giant ◽  
M Stars

AbstractFourteen red variables in the southern globular clusters 47 Tuc, ω Cen, and NGC 362 have been observed on an eight-color system of narrow-band photometry in the near infrared. Temperatures are derived from blackbody fits to the calibrated fluxes, and spectral types are given for the M stars. The types observed for the three Mira variables in 47 Tuc range from M3.1 to M7.5; two small-range variables in the same cluster are later than M4. The variables in ω Cen are mostly earlier than K5, but spectra of types M3 and MO were also encountered among radial-velocity members. In both the metal-rich 47 Tuc and the metal-poor ω Cen, the relation between TiO band strength and temperature is approximately normal. Several of these stars fall well above or below the red giant branches of their clusters in diagrams of infrared magnitude against temperature. Comparisons are made with recent results obtained at Radcliffe Observatory on some of the same stars.

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