Name: Rogemar A. Riffel

Institution: IF-UFRGS

e-mail: rogemar(no-spam)ufrgs.br

Partner Contry: BRA

Science Meeting: Yes

User Meeting: None Selected

NGO Staff Meeting: None Selected

Presentation: Yes

Format: Poster

Title: Near infrared spatially resolved two-dimensional stellar and gaseous kinematics of the central region of NGC4051 and NGC7582

Co-author:Thaisa Storchi-Bergmann (1), Claudia Winge (2), Peter McGregor (3), Michael Dopita (3),Karl Gebhardt (4)

Co-authors' Institutions: (1) Universidade Federal do Rio Grande do Sul, IF;(2) Gemini Observatory, c/o AURA Inc.;(3) Research School of Astronomy and Astrophysics, The Australian National University; (4) Astronomy Department, University of Texas

Abstract:

We present two-dimensional (2D) gaseous and stellar kinematics of the central region of the galaxy NGC4051 at a sampling of ∼4.5 pc², and NGC7582, at a sampling of ∼16 pc². The spectroscopic observations at R=5290 of NGC4051 were obtained with the Near-infrared Integral Field Spectrometer (NIFS) at the Gemini North while those of NGC7582 were obtained with the Integral Field Unit of the Gemini Near Infrared Spectrograph (GNIRS) at Gemini South at R=5900. We present 2D maps for intensities, radial velocities and velocity dispersions from the the H₂ and Brγ emission lines at the K-band. Emission line "tomography" is provided by velocity slices across each emission line profile which allows the mapping not only the peak velocities but including also the wings. We compare the maps for NGC4051 with a radio continuum image and find signatures of interaction between a radio jet and the circumnuclear gas, in the form of enhancement of the the H₂ flux in the jet region and blueshifts of up to 200 km s^-1. For NGC7582, the H₂ and Brγ flux distributions trace star forming regions delineating a partial ring around the nucleus, which is also observed in the emission line "tomography". We have also obtained stellar kinematic maps by direct fitting of the CO absortion bandheads (around 2.3μm) with stellar template spectra. The stellar radial velocity fields of both galaxies are dominated by rotation. For NGC4051, the stellar velocity dispersions present values ranging from ∼50 to ∼70 km s^-1, which are used to constrain the mass of the nuclear supermassive black hole. For NGC7582 the velocity dispersions shows a partial ring of low values at the location of the star forming regions.