Integral Field Spectroscopy of the inner kpc of the elliptical galaxy NGC 5044

Abstract

We used Gemini Multi-Object Spectrograph (GMOS) in the Integral Field Unit mode to map the stellar population, emission line flux distributions and gas kinematics in the inner kpc of NGC 5044. From the stellar populations synthesis we found that the continuum emission is dominated by old high metallicity stars ($\sim$13 Gyr, 2.5Z$\odot$). Also, its nuclear emission is diluted by a non thermal emission, which we attribute to the presence of a weak active galactic nuclei (AGN). In addition, we report for the first time a broad component (FWHM$\sim$ 3000km$s^{-1}$) in the H$\alpha$ emission line in the nuclear region of NGC 5044. By using emission line ratio diagnostic diagrams we found that two dominant ionization processes coexist, while the nuclear region (inner 200 pc) is ionized by a low luminosity AGN, the filamentary structures are consistent with being excited by shocks. The H$\alpha$ velocity field shows evidence of a rotating disk, which has a velocity amplitude of $\sim$240kms${}^{-1}$ at $\sim$ 136 pc from the nucleus. Assuming a Keplerian approach we estimated that the mass inside this radius is $1.9\times 10^9$ $M_{\odot }$, which is in agreement with the value obtained through the M-$\sigma$ relation, $M_{SMBH}=1.8\pm 1.6\times 10^9{M}_{\odot }$. Modelling the ionized gas velocity field by a rotating disk component plus inflows towards the nucleus along filamentary structures, we obtain a mass inflow rate of $\sim$0.4 M${}_{\odot }$. This inflow rate is enough to power the central AGN in NGC 5044.

16 pages, 12 figures, accepted by MNRAS

References in corpus (16)

• The Host Galaxies and Classification of Active Galactic Nuclei
• The MAPPINGS III Library of Fast Radiative Shock Models
• The star formation history of early-type galaxies as a function of mass and environment
• Probing the near infrared stellar population of Seyfert galaxies
• Molecular Gas in the X-ray Bright Group NGC 5044 as Revealed by ALMA
• P-MaNGA: Emission Lines Properties - Gas Ionisation and Chemical Abundances from Prototype Observations
• PCA Tomography: how to extract information from datacubes
• Spitzer Observations of Transient, Extended Dust in Two Elliptical Galaxies: New Evidence of Recent Feedback Energy Release in Galactic Cores
• Line strengths of early-type galaxies
• Probing the Physics of Narrow Line Regions in Active Galaxies III: Accretion and Cocoon Shocks in the LINER NGC1052
• The history of star formation and mass assembly in early-type galaxies
• Probing the Circumnuclear Stellar Populations of Starburst Galaxies in the Near-infrared
• IFU spectroscopy of 10 early-type galactic nuclei - III. Properties of the circumnuclear gas emission
• IFU spectroscopy of 10 early type galactic nuclei: II - Nuclear emission line properties
• The elliptical galaxy NGC 5044: Stellar population and ionized gas
• Photometry and dynamics of the minor mergers AM\,1228-260 and AM\,2058-381

Cited by in corpus (1)

• Observational Constraints on the Feeding of Supermassive Black Holes