216 research outputs found
Significant Suppression of Star Formation in Radio-Quiet AGN Host Galaxies with Kiloparsec-Scale Radio Structures
We conducted 22~GHz 1" JVLA imaging of 100 radio-quiet X-ray selected AGN
from the Swift-BAT survey. We find AGN-driven kiloparsec-scale radio structures
inconsistent with pure star formation in 11 AGN. The host galaxies of these AGN
lie significantly below the star-forming main sequence, indicating suppressed
star formation. While these radio structures tend to be physically small
compared to the host galaxy, the global star formation rate of the host is
affected. We evaluate the energetics of the radio structures interpreted first
as immature radio jets, and then as consequences of an AGN-driven radiative
outflow, and compare them to two criteria for successful feedback: the ability
to remove the CO-derived molecular gas mass from the galaxy gravitational
potential and the kinetic energy transfer to molecular clouds leading to
. In most cases, the jet interpretation is
insufficient to provide the energy necessary to cause the star formation
suppression. Conversely, the wind interpretation provides ample energy in all
but one case. We conclude that it is more likely that the observed suppression
of star formation in the global host galaxy is due to ISM interactions of a
radiative outflow, rather than a small-scale radio jet.Comment: 15 pages, 3 figures, 2 tables. Accepted for publication in the
Astrophysical Journa
Semiclassical Theory for Parametric Correlation of Energy Levels
Parametric energy-level correlation describes the response of the
energy-level statistics to an external parameter such as the magnetic field.
Using semiclassical periodic-orbit theory for a chaotic system, we evaluate the
parametric energy-level correlation depending on the magnetic field difference.
The small-time expansion of the spectral form factor is shown to be
in agreement with the prediction of parameter dependent random-matrix theory to
all orders in .Comment: 25 pages, no figur
Meson Correlators in Finite Temperature Lattice QCD
We analyze temporal and spatial meson correlators in quenched lattice QCD at T>0. Below T_c we observe little change in the meson properties as compared with T=0. Above T_c we observe new features: chiral symmetry restoration and signals of plasma formation, but also indication of persisting mesonic (metastable) states and different temporal and spatial masses in the mesonic channels. This suggests a complex picture of QGP in the region 1 - 1.5 T_c
Numerical Study of Length Spectra and Low-lying Eigenvalue Spectra of Compact Hyperbolic 3-manifolds
In this paper, we numerically investigate the length spectra and the
low-lying eigenvalue spectra of the Laplace-Beltrami operator for a large
number of small compact(closed) hyperbolic (CH) 3-manifolds. The first non-zero
eigenvalues have been successfully computed using the periodic orbit sum
method, which are compared with various geometric quantities such as volume,
diameter and length of the shortest periodic geodesic of the manifolds. The
deviation of low-lying eigenvalue spectra of manifolds converging to a cusped
hyperbolic manifold from the asymptotic distribution has been measured by
function and spectral distance.Comment: 19 pages, 18 EPS figures and 2 GIF figures (fig.10) Description of
cusped manifolds in section 2 is correcte
Quenched charmonium near the continuum limit
We study relativistic charmonium on very fine quenched lattices (beta=6.4 and 6.6). We concentrate on the calculation of the hyperfine splitting between eta_c and J/psi, aiming for a controlled continuum extrapolation of this quantity. Results for the eta_c and J/psi wave functions are also presented
Screening mass responses to chemical potential at finite temperature
Responses to chemical potential of the pseudoscalar meson screening mass and the chiral condensate in lattice QCD are investigated. On a lattice with two flavors of staggered quarks the first and second responses below and above are evaluated. Different behavior in the low and the high temperature phases are observed, which may be explained as a consequence of the chiral symmetry breaking and restoration
Lattice calculations of meson correlators and spectral functions at finite temperature
I review recent progress in relating meson spectral function to imaginary
time correlation function at finite temperature calculated on isotropic as well
as on anisotropic lattices. Special attention is payed for the lattice
artifacts present in calculation of meson spectral functions. Results in the
case of light quarks as well as heavy quarks are reviewed which indicate in
particular that even in the chiral limit meson spectral functions have
non-trivial structure and the ground state quarkonia survive up to temperature
1.5T_cComment: Invited plenary talk presented at SQM03 (Atlantic Beach, March 12-17,
2003), 10 pages LaTeX, uses iopams.sty, iopart.cl
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