119 research outputs found
Gas and stellar dynamics in NGC 1068. Probing the galactic gravitational potential
We present Sauron 2D spectrography of the central 1.5 kpc of the nearby Sey2
galaxy NGC1068, encompassing the well-known NIR inner bar. We have successively
disentangled the respective contributions of the ionized gas and stars, thus
deriving their 2D distribution and kinematics. The [OIII] and Hbeta emission
lines exhibit very different spatial distribution and kinematics, the latter
following inner spiral arms with clumps associated with star formation. Strong
inwards streaming motions are observed in both the Hbeta and [OIII] kinematics.
The stellar kinematics also exhibit clear signatures of a non-axisymmetric
tumbling potential, with a twist in both the velocity and h3 fields. We
re-examined the long-slit data of Shapiro et al (2003) using pPXF: a strong
decoupling of h3 is revealed, and the central decrease in h4 hinted in the
Sauron data is confirmed. These data also suggest that NGC1068 is a good
candidate for a so-called sigma-drop. We confirm the possible presence of two
pattern speeds. We also examine the stellar kinematics of bars formed in
N-body+SPH simulations built from axisymmetric initial conditions. These
successfully reproduce a number of properties observed in the 2D kinematics of
NGC1068, and the long-slit data, showing that the kinematic signature of the
NIR bar is imprinted in the stellar kinematics. The remaining differences
between the models and the observed properties are mostly due to the exclusion
of star formation and the lack of the primary large-scale oval/bar in the
simulations. These models suggest that the inner bar could drive a significant
amount of gas down to a scale of ~300 pc. This is consistent with the
interpretation of the sigma-drop in NGC1068 being the result of central gas
accretion followed by an episode of star formation.Comment: accepted for publication in MNRAS, 20 pages, 17 figures (high res
version available at
www-obs.univ-lyon1.fr/eric.emsellem/preprints/NGC1068_Emsellemetal_final.pdf
UNIVERSITY OF THE STATE OF NEW YORK - THE TWENTY-SEVENTH ANNUAL REPORT OF THE FACULTY OF THE COLLEGE OF THE CITY OF NEW YORK TO THE BOARD OF TRUSTEES, DECEMBER, 1878.
Report four from the sixth bound volume of ten which documents in part the first nineteen years of The Free Academy, the predecessor of the educational institution, City College of New York. COLLEGE OF THE CITY OF NEW YORK. 1856-96. REPORTS OF THE FACULTY II, includes 21 individual reports. At a time when municipal education constituted primary schooling, citizens united in response to arguments presented by a merchant and Board of Education President, Townsend Harris, for the necessity of an institution that would provide advanced training for future generations of citizens to fully engage in the professions advantageous to an expanding urban center. Includes preliminary reports that commented on the application of resources for the creation of the institution and the annual reports of the faculty, demonstrating accountability to the Board of Education with regard to the operation of the facility., UNIVERSITY OF THE STATE OF NEW YORK - THE TWENTY-SEVENTH ANNUAL REPORT OF THE FACULTY OF THE COLLEGE OF THE CITY OF NEW YORK TO THE BOARD OF TRUSTEES, DECEMBER, 1878. [11 pages (1-11), 1878], RG
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