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PROGRAMING
FUTURE COLLABORATIONS
Propositions Hot Emission Stars During
this workshop, in the field of hot
emission stars, the following propositions have been made: 1.
A statistical study of many stars in different ionization potential
regions, using the GR model. With the results of this study, we will be able
to make a model for all the gaseous areas around hot emission stars. E.
Danezis, A. Antoniou & E. Lyratzi 2.
A study of the time scale variation of all the parameters of some
characteristic hot emission stars, using the GR model. E.
Danezis, A. Antoniou & E. Lyratzi The
astrophysical spectroscopy teams of the University
of Athens
and the Observatory of Belgrade are already working on these two
propositions, in the frame of the scientific collaboration between Greece
and Serbia. Whoever wants to participate in this project is welcome. 3.
An experimental study in order to verify the existence of density
regions of matter able to construct spectral line (emission or absorption),
like the spectral lines that we can detect in the spectra of hot emission
stars J.
Purić, N. Cvetanović, B. M. Obradović, I.
P. Dojčinović & M. M. Kuraica This
program is the subject of the collaboration between the scientific team of
Prof. Purić in University
of Belgrade
and the Astrophysical Spectroscopy teams of the University
of 4.
A probabilistic method to extract the exact number of satellite
components in which a complex spectral line profile can be decomposed.
Through this method, the width and the intensity can also be estimated. M.
Avlonitis & A. Pappa This
program is the subject of the collaboration between the scientific team of
Dr. Avlonitis in Ionian University
and the Astrophysical Spectroscopy team of the University
of Athens. Whoever wants
to participate in this project is welcome. 5.
Proposition of Magdalena Christova (no abstract) 6.
Proposition of Zoran Simić (no abstract) Quasars During
this workshop, in the field of quasars,
the following propositions have been made: 1.
A study of the physical parameters of many spectral lines of a group
of quasars using a combination of GR model and disk model. E.
Danezis, E. Lyratzi & A. Antoniou The
astrophysical spectroscopy teams of the University
of Athens
and the Observatory of Belgrade are already working on these two
propositions, in the frame of the scientific collaboration between Greece
and Serbia. Whoever wants to participate in this project is welcome. 2.
There are
many observed
spectra collected by the group of Prof. Piero Rafanelli, who proposed to use
these spectra for all kind of investigation of quasars. P. Rafanelli
Interested in this
proposition:
1.
Astrophysical spectroscopy team of
University
of Athens. 2.
Astrophysical spectroscopy team of Astronomical Observatory of
Belgrade 3.
Dr. Magdalena Christova, Department of Applied Physics, Technical University of Sofia,
Bulgaria
3.
Edi Bon proposed to collaborate in developing a two-component model
especially, to apply this model on different spectra of quasars. 4.
Proposals of Predrag Jovanović are to investigate the emission of the
accretion disk around super-massive black holes, supposed to be in quasar
center. Also, some micro-gravitational influence on line profiles emitted
from the disk. 5.
Finally, we have a proposition from Markos Avlonitis from the Ionian
University, which combines most of the previous propositions in one, aiming to a
European financing.
1.
There are four groups which will collaborate in the subject of
“Investigation on the nature and structure of Active Galactic Nuclei,
using emission/absorption lines” ( 2.
All the participants are invited to agree in a common collaboration
for a PF7 proposal. This collaboration has been proposed by Markos Avlonitis
(Ionian University), Manos Danezis, Valia Lyratzi, Anastasia Pappa and Antonis Antoniou (University
of Athens). It has been agreed that the proposal will be sent electronically to all
the participants, in order to make comments and suggestions. Whoever is
interested in this collaboration is invited to participate in. A next step
is to decide on the supervisor of the PF7 proposal. The proposal has been
written by Anastasia Pappa and is the following: Proposal for a possible FP7 collaboration Understanding the physical mechanism in hot emission stars, AGNs and quasars Following
the round table discussions during this workshop, it has emerged a common
theme of interest - the understanding of the physical mechanism that
produces the spectra in hot emission stars, AGNs and quasars using a variety
of complementary methods and techniques. Here
we propose that we unite our efforts under an FP7 proposal. A successful
submission of an fp7 proposal will allow us to coordinate our efforts
better, provide funding for travelling, organising similar workshops and
meetings and provide financial support to hire researchers. Below
there is a short description of the scientific case for building this
collaboration towards an fp7 proposal. This section could provide the
framework in which the complete scientific case can be finalised. Hot
emission stars, AGNs and quasars show complex spectra. The detailed study of
their spectra can unlock the physical mechanism that powers them and unveil
a range of interesting and exotic phenomena. To
achieve this, we study observational data and use mathematical modelling
techniques to derive kinematical
parameters of the lines. This, in turn allows us to test theoretical models.
To that end the astrophysical spectroscopy team of the University
of Athens has already developed a model which gives the properties of the lines in hot
emission stars (apparent
rotational and radial velocities, the random velocities of the ions, the
Full Width at Half Maximum, the optical depth, the column density and the
absorbed or emitted energy). Using those parameters they can describe the
structure of the regions that produce the observed lines in hot emission
stars. However, in order to study and to model the whole area around hot
emission stars (Be and Oe stars), in UV, we have to calculate the parameters
of many regions with different ionization potential (e.g. N V, C IV, N IV,
Si IV, Al III, Fe II, Mg II, Lyα,
Hα.
Using their GR
model, we can calculate many parameters of the density regions where the
studied spectral lines are created. They have concluded that the lines are
produced in independent density regions around the star. Further work
includes a statistical study of many ions in different ionization potential
regions of many stars. With the results of this study, they will be able to
make a model for all the gaseous areas around hot emission stars. Time scale
variation of all the parameters of some characteristic hot emission stars is
also required. Finally the model could be extended to allow for the modeling
of the region around AGNs and quasars. On
the other hand, Avlonitis M. and Pappa A. proposed a stochastic method for
deriving some of the line parameters in complex line profiles, which allow
the exact reconstruction of the lines. According to this method the lines
may be treated as random signals which can be considered as superposition of
independent signals. The number of independent signals can then be
considered equal with the number of the interfered lines that make up the
complex line profile. The results of that method can then be fed into the
mathematical modelling applications such the one used by the Athens group and return results with the highest possible confidence level. Towards
the understanding of the mechanism that produces the line profiles in stars,
AGNs and quasars Purić J. et al. propose to
apply some methods from laboratory plasma which could enable us to shed
light into the physical conditions in this region. By simulating in
laboratory the physical conditions of the gaseous envelope or disk around
hot emission stars and quasars they expect to find
out if density regions similar with the ones that create the DACs and SACs
lines in hot emission stars and quasars can be created in the laboratory as
well as resultant light absorption. Using
those techniques we could for the first time tackle the issue of
astrophysical winds and disks in stars, AGNs and quasars in a complete
manner. Please
note that many other round table participants contributed their ideas, which
could now be discussed in more detail and be included in a possible fp7
proposal. |
