222,959 research outputs found
Supermassive black holes from OASIS and SAURON integral-field kinematics
Supermassive black holes are a key element in our understanding of how
galaxies form. Most of the progress in this very active field of research is
based on just ~30 determinations of black hole mass, accumulated over the past
decade. We illustrate how integral-field spectroscopy, and in particular our
OASIS modeling effort, can help improve the current situation.Comment: 4 pages, 2 figures, LaTeX. To appear in the proceedings of IAU
Symposium 245 "Formation and Evolution of Galaxy Bulges", M. Bureau, E.
Athanassoula, and B. Barbuy, ed
Photonics and Spectroscopy in Nanojunctions: A Theoretical Insight
Progress of experimental techniques at nanoscale in the last decade made
optical measurements in current-carrying nanojunctions a reality thus
indicating emergence of a new field of research coined as optoelectronics.
Optical spectroscopy of open nonequilibrium systems is a natural meeting point
for (at least) two research areas: nonlinear optical spectroscopy and quantum
transport, each with its own theoretical toolbox. We review recent progress in
the field comparing theoretical treatments of optical response in nanojunctions
as is accepted in nonlinear spectroscopy and quantum transport communities. A
unified theoretical description of spectroscopy in nanojunctions is presented.
We argue that theoretical approaches of the quantum transport community (and in
particular, the Green function based considerations) yield a convenient tool
for optoelectronics when radiation field is treated classically, and that
differences between the toolboxes may become critical when studying quantum
radiation field in junctions.Comment: 48 pages, 13 figure
Quasars in the 4D Eigenvector 1 Context: A stroll down memory lane
Recently some pessimism has been expressed about our lack of progress in
understanding quasars over the 50+ year since their discovery. It is worthwhile
to look back at some of the progress that has been made - but still lies under
the radar - perhaps because few people are working on optical/UV spectroscopy
in this field. Great advances in understanding quasar phenomenology have
emerged using eigenvector techniques. The 4D eigenvector 1 context provides a
surrogate H-R Diagram for quasars with a source main sequence driven by
Eddington ratio convolved with line-of-sight orientation. Appreciating the
striking differences between quasars at opposite ends of the main sequence
(so-called population A and B sources) opens the door towards a unified model
of quasar physics, geometry and kinematics. We present a review of some of the
progress that has been made over the past 15 years, and point out unsolved
issues.Comment: 27 pages, 6 figure
Penta-quark states with hidden charm and beauty
More and more hadron states are found to be difficult to be accommodated by
the quenched quark models which describe baryons as 3-quark states and mesons
as antiquark-quark states. Dragging out an antiquark-quark pair from the gluon
field in hadrons should be an important excitation mechanism for hadron
spectroscopy. Our recent progress on the penta-quark states with hidden charm
and beauty is reviewed.Comment: Plenary talk at the 5th Asia-Pacific Conference on Few-Body Problems
in Physics 2011 (APFB2011), 22-26 Aug., 2011, Seoul, Kore
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