Extragalactic globular cluster near-infrared spectroscopy: I. Integrated near-infrared spectra of Centaurus A/NGC 5128

Abstract

One way to constrain the evolutionary histories of galaxies is to analyse their stellar populations. In the local Universe, our understanding of the stellar population properties of galaxies has traditionally relied on the study of optical absorption and emission-line features. In order to overcome limitations intrinsic to this wavelength range, such as the age-metallicity degeneracy and the high sensitivity to dust reddening, we must use wavelength ranges beyond the optical. The near-infrared (NIR) offers a possibility to extract information on spectral signatures that are not as obvious in traditional optical bands. Moreover, with the current and forthcoming generation of instrumentation focusing on the NIR, it is mandatory to explore possibilities within this wavelength range for nearby-Universe galaxies. However, although the NIR shows great potential, we are only beginning to understand it. Widely used techniques such as a full spectral fitting and line strength indices need to be tested on systems that are as close to simple stellar populations as possible, and the result from the techniques need to be compared to the yields from a traditional optical analysis. We present a NIR spectral survey of extragalactic globular clusters (GCs). The set was composed of 21 GCs from NGC5128 that were obtained with SOAR/TripleSpec4, which covered the ~1.0-2.4$\mu$m range with a spectral resolution R=$\lambda /\Delta \lambda$ of 3500. These spectra cover H$\beta$ equivalent widths between 0.98$\mathring{A}$ and 4.32$\mathring{A}$, and [MgFe]' between 0.24$\mathring{A}$ and 3.76$\mathring{A}$. This set is ideal for performing absorption band measurements and a full spectral fitting, and it can be used for kinematic studies and age and abundance measurements. With this library, we expect to be able to probe the capabilities of NIR models, as well as to further improve stellar population estimates for the GCs around NGC5128.

10 pages, 3 figures

References in corpus (29)

• The propagation of uncertainties in stellar population synthesis modeling I: The relevance of uncertain aspects of stellar evolution and the IMF to the derived physical properties of galaxies
• UV-extended E-MILES stellar population models: young components in massive early-type galaxies
• Star formation in a galactic outflow
• The Visible and Infrared Survey Telescope for Astronomy (VISTA): Design, Technical Overview and Performance
• The SAGES Legacy Unifying Globulars and GalaxieS Survey (SLUGGS): Sample definition, methods, and initial results
• A 2dF spectroscopic study of globular clusters in NGC 5128: Probing the formation history of the nearest giant Elliptical
• Probing the near infrared stellar population of Seyfert galaxies
• The Star Formation History and Evolution of the Circumnuclear Region of M100
• The first detection of near-infrared CN bands in active galactic nuclei: signature of star formation
• The Nuclear Near-Infrared Spectral Properties of Nearby Galaxies
• On the Metallicity-Color Relations and Bimodal Color Distributions in Extragalactic Globular Cluster Systems
• MILES extended: Stellar population synthesis models from the optical to the infrared
• Comparison of Stellar Population Model Predictions Using Optical and Infrared Spectroscopy
• The Stellar Populations of Starburst Galaxies Through near infrared spectroscopy
• The SLUGGS survey: Globular cluster stellar population trends from weak absorption lines in stacked spectra
• The Stellar Spectral Features of Nearby Galaxies in the Near-Infrared: Tracers of Thermally-Pulsing Asymptotic Giant Branch Stars?
• Optical/NIR stellar absorption and emission-line indices from luminous infrared galaxies
• Infrared High-Resolution Integrated Light Spectral Analyses of M31 Globular Clusters from APOGEE
• The Next Generation Virgo cluster Survey (NGVS). XXV. Fiducial panchromatic colors of Virgo core globular clusters and their comparison to model predictions
• Mapping the stellar population and gas excitation of MaNGA galaxies with MEGACUBES. Results for AGN versus control sample
• Probing the Circumnuclear Stellar Populations of Starburst Galaxies in the Near-infrared
• Gemini NIFS survey of feeding and feedback processes in nearby Active Galaxies: VI -- Stellar Populations
• Deriving ages and horizontal branch properties of integrated stellar populations
• Strong CO Absorption Features in Massive ETGs
• New Constraints on a complex relation between globular cluster colors and environment
• HR-pyPopStar: high wavelength-resolution stellar populations evolutionary synthesis model
• Outflows, Inflows and Young Stars in the inner 200 pc of the Seyfert galaxy NGC 2110
• Optical Properties of Peaked Spectrum Radio Sources
• The metal-poor dwarf irregular galaxy candidate next to Mrk 1172