Two-dimensional kinematics of the central region of NGC4501 from GMOS/Gemini integral field spectroscopy
Abstract
We present two-dimensional stellar and gas kinematics in the central region of the Seyfert 2 galaxy NGC 4501 from optical Integral Field Spectroscopy obtained with Gemini Multi-Object Spectrograph (GMOS) at Gemini-North telescope. The final data cube contains ∼ 16000 spectra covering the inner 7" × 15" at spatial resolution of ∼ 50 pc and covering the spectral region from 5600 Å to 7000 Å at a spectral resolution of 2.7 Å (FWHM). Two-dimensional maps for the flux, velocity and velocity dispersion (σ) were obtained from the fitting of the emission-line profiles of Hα, [N II] λ λ 6548,6584 and [S II] λ λ 6717,6731. All lines present extended emission to up to 5" the peak of flux of the nuclear at it. The gas velocity field for all lines are similar, being dominated by rotation in the plane of the galaxy with a velocity amplitude of 100 km^{-1}, although deviations from rotation are seen at some locations. On the far side of the galaxy we observed blueshifts and on the near side redshifts along spiral structures, being interpreted as inflows towards the nucleus of NGC 4501. The forbidden lines show σ values ranging from 50 to 150 km s^{-1} while the Hα shows overall smaller values, with the highest ones reaching ∼ 100 km s^{-1}. The highest σ values for all emission lines are observed at 2-3 arcsec northeast from the nucleus, being co-spatial with a distortion seen in the velocity field. The electron density map obtained from the [S II] λ λ 6731/6716 line ratio shows values between 100 cm^{-3} the nucleus to 900 cm^{-3} in a ring of high densities.
- Publication:
-
Revista Mexicana de Astronomia y Astrofisica Conference Series
- Pub Date:
- October 2014
- Bibcode:
- 2014RMxAC..44..190B