English
Related papers

Related papers: The HST Large Program on Omega Centauri. I. Multip…

200 papers

We present spectroscopic abundances and radial velocities for giant stars in the Galactic globular cluster omega Centauri based on the CaII infrared triplet. Two samples of stars were observed: 234 stars at M_V = 1.25 on the lower giant…

Astrophysics · Physics 2009-10-05 Nicholas B. Suntzeff , Robert P. Kraft

We present radial velocities, Fe, and Al abundances for 180 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri ($\omega$ Cen). The majority of our data lie in the range 11.0$<$V$<$13.5, which covers the RGB from…

We derive abundances of Fe, Na, O, and s-elements from GIRAFFE@VLT spectra for more than 200 red giant stars in the Milky Way satellite Omega Centauri. Our preliminary results are that: (i) we confirm that Omega Centauri exibiths large…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. F. Marino , G. Piotto , R. Gratton , A. P. Milone , M. Zoccali , L. R. Bedin , S. Villanova , A. Bellini

We perform a combined analysis of stellar kinematics and line-of-sight accelerations of millisecond pulsars to investigate the mass contents of Omega Centauri. We consider multiple mass components: the visible photometric distribution, a…

Astrophysics of Galaxies · Physics 2025-01-15 Andrés Bañares-Hernández , Francesca Calore , Jorge Martin Camalich , Justin I. Read

We used archival multi-band Hubble Space Telescope observations obtained with the Wide-Field Camera 3 in the UV-optical channel to present new important observational findings on the color-magnitude diagram (CMD) of the Galactic globular…

Astrophysics of Galaxies · Physics 2015-05-19 Bellini A. , Bedin L. R. , Piotto G. , Milone A. P. , Marino A. F. , Villanova S.

We present new intermediate-band Stroemgren photometry based on more than 300 u,v,b,y images of the Galactic globular cluster Omega Cen. Optical data were supplemented with new multiband near-infrared (NIR) photometry (350 J,H,K_s images).…

We present results of an extensive spectroscopic survey of Subgiant stars in the stellar system omega Centauri. Using infrared CaII triplet lines, we derived metallicities and radial velocities for more than 250 stars belonging to different…

Astrophysics · Physics 2009-11-13 A. Sollima , E. Pancino , F. R. Ferraro , M. Bellazzini , O. Straniero , L. Pasquini

By means of deep FORS1@VLT and ACS@HST observations of a wide area in the stellar system omega Cen we measured the luminosity function of main sequence stars down to R=22.6 and I_{F814W}=24.5 . The luminosity functions obtained have been…

Astrophysics · Physics 2009-11-13 A. Sollima , F. R. Ferraro , M. Bellazzini

Dust production is explored around 14 metal-poor ([Fe/H] = -1.91 to -0.98) giant stars in the Galactic globular cluster omega Centauri using new Spitzer IRS spectra. This sample includes the cluster's post-AGB and carbon stars and is thus…

Using the 2dF multi-fibre instrument on the AAT, moderate resolution spectra have been obtained for a large sample of stars on the main sequence and at the turnoff in the unusual globular cluster omega Centauri. We investigate the behaviour…

Astrophysics · Physics 2009-11-11 G. S. Da Costa , Laura Stanford , John E. Norris , R. D. Cannon

We present results of a search for optical counterparts of X-ray sources in and toward the globular cluster Omega Centauri (NGC 5139) using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The ACS data consist of a…

Solar and Stellar Astrophysics · Physics 2015-06-12 Adrienne M. Cool , Daryl Haggard , Tersi Arias , Michelle Brochmann , Jason Dorfman , April Gafford , Vivian White , Jay Anderson

The globular cluster $\omega$ Centauri (NGC 5139) is a puzzling stellar system harboring several distinct stellar populations whose origin still represents a unique astrophysical challenge. Current scenarios range from primordial chemical…

Astrophysics of Galaxies · Physics 2014-11-20 Sandro Villanova , Giovanni Carraro , Riccardo Scarpa , Gianni Marconi

Omega Centauri ($\omega$ Cen) is one of the most complex star clusters in the Milky Way, and likely the stripped nucleus of an accreted dwarf galaxy. Being the subject of debate between it hosting an intermediate-mass black hole (IMBH) or a…

Astrophysics of Galaxies · Physics 2025-03-26 S. Saracino , S. Kamann , F. Wragg , S. Dreizler , K. Kremer , M. Latour , J. Müller-Horn , N. Neumayer , A. C. Seth , G. van de Ven , M. Häberle

CCD vby Stroemgren photometry of a statistically complete sample of red giants and stars in the main sequence turn-off region in omega Centauri has been used to analyse the apparently complex star formation history of this cluster. From the…

Astrophysics · Physics 2009-10-05 Michael Hilker , Tom Richtler

We present high-precision multi-band photometry for the globular cluster (GC) M2. We combine the analysis of the photometric data obtained from the Hubble Space Telescope UV Legacy Survey of Galactic GCs GO-13297, with chemical abundances…

In this study, we report the results of Fe, Mg, Al, and Si abundances analysis for a sample of 439 stars in Omega Centauri, using high-resolution spectra obtained with the VLT/FLAMES multi-object spectrograph. Our analysis reveals the…

Solar and Stellar Astrophysics · Physics 2024-01-10 Deimer Antonio Alvarez Garay , Alessio Mucciarelli , Michele Bellazzini , Carmela Lardo , Paolo Ventura

Medium resolution spectra of more than 400 subgiant and turn-off region stars in Omega Centauri were analysed. The observations were performed at the VLT/Paranal with FORS2/MXU. In order to determine the metallicities of the sample stars,…

Astrophysics · Physics 2007-05-23 Andrea Kayser , Michael Hilker , Tom Richtler , Philip G. Willemsen

We investigate the formation processes of the Galactic globular cluster (GC) omega Cen with multiple stellar populations based on our original hydrodynamical simulations with chemical enrichment by Type II supernovae (SNe II), asymptotic…

Astrophysics of Galaxies · Physics 2020-01-08 Kenji Bekki , Takuji Tsujimoto

We present abundances of several light, alpha, Fe-peak, and neutron-capture elements for 66 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri. Our observations lie in the range 12.0<V<13.5 and focus on the…

Solar and Stellar Astrophysics · Physics 2011-02-11 Christian I. Johnson , Catherine A. Pilachowski , R. Michael Rich , Jon P. Fulbright

We have determined stellar parameters and abundances for 221 giant branch stars in the globular cluster {\omega} Centauri. A combination of photometry and lower-resolution spectroscopy was used to determine temperature, gravity,…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jeffrey D. Simpson , P. L. Cottrell , C. C. Worley