Astronomical Spectroscopy & the Virtual Observatory - ESAC – March 23 rd 2007 Stefano Bianchi...
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Transcript of Astronomical Spectroscopy & the Virtual Observatory - ESAC – March 23 rd 2007 Stefano Bianchi...
Astronomical Spectroscopy & the Virtual Observatory - ESAC – March 23rd 2007
Stefano Bianchi
Matteo Guainazzi Isa Barbarisi Pedro Osuna Jesus Salgado
Guainazzi et al. 2005
Predicted starburst contribution
Ac
tua
l s
oft
X-r
ay
lu
min
os
ity
Turner et al. 1997
ASCA
Soft X-ray excess in obscured AGN
NGC1068Kinkhabwala et al. 2002
Detection of narrow Radiative Recombination
Continua (RRC)=>
Low temperature gas=>
Photoionization(Liedhal et al. 1995)
Diagnostic on triplets AND higher order series lines:• confirm photoionization• constraint <10% contribution from collisional plasma• unveil the important role of resonant scattering(Band et al. 1990, Matt 1994, Krolik & Kriss 1995)
We proudly announceproudly announce the first catalogue of soft X-ray emission lines in a sample which includes all the type ≥ 1.5 AGNall the type ≥ 1.5 AGN observed by the RGSRGS
CIELO-AGN[Catalogue of Ionized Emission Lines in Obscured-AGN]
66 objects<F0.1-2 keV> ~ 10-13 cgs
• OVIII Lyα detected in ~50% of the sample• OVII triplet in ~40%• Many other lines from O, Fe, C, Si, Mg, Ne, N detected in ~15%
Guainazzi & Bianchi 2007
Critical diagnostics
RRCs are:CommonCommon (detected in 40% o.t.s.)
NarrowNarrow (σ<10 eV)=>
Photoionization
Strong higher order lines=>
Resonant scattering
Where is the gas?
Circinus
Sm
ith &
Wils
on
20
01
NGC4151
Yang e
t al. 2
00
1
NGC3393 – z=0.0125
NGC1386 – z=0.0029
Bia
nch
i et
al. 2
006
(+
6 o
ther
obje
cts)
What is the gas?
The comparison between the Chandra and the HST images shows that the [OIII]/soft X-ray ratio is fairly constant along with the
radius, up to hundreds of pc. Photoionization models reproduce this behavior if ner-β, with β=2 (i.e. constant ionization
parameter). This is in agreement with NLR emission line ratios(e.g. Kraemer et al. ’00, Kraemer & Crenshaw ’00, Bradley et al. ’04, Collins et al.
‘05).
Bianchi et al., 2007
What about the starburst contribution?
HST Chandra
110 pc
3 pc
In the immermost 110 pc:• low luminosity AGN: LX≈1039 erg s-1
• young stellar cluster: LX≈6×1038 erg s-1
NGC4303
Jiménez-Bailón et al. 2003NGC7130
Levenson et al. 2005
AGN
-Total LO≥1040 erg s-1
-OVII/OVIII≥1
So… AGN or starburst? Empirical diagnostic diagram based on high resolution spectroscopy
Guainazzi & Bianchi 2007
STARBURST
… of course this is too simple
OVIII/OVII excess is NOT
coincident with star formation
regions!Bianchi et al., 2007 NGC7582
The VO Connection
One needs: A Data Model, i.e. a standard abstract representation of
the database structure A Data Access Protocol, i.e. standard rules to be
followed by software designed to access line databases A Software Implementation capable of interfacing with
other access protocols (spectra, images etc.)
The process is close to be finalized: Relevant documents aiming at being
promoted to formal recommendation at the next IVOA Interoperability Meeting
The International Virtual Observatory Alliance started about 2 years ago a discussion on how to make line
catalogues accessible in the VO context
SeeJ. Salgado’s
Talk
Why is the Line Data Model appropriate for us?
1. It supports atomic and molecular “laboratory” databases as well as catalogue of observed lines (such as
CIELO)
2. It is organized around the concept of line
3. It allows catalogue publishers to provide full characterization of the atomic/molecular state, the
physical processes generating a line and the physical properties of the plasma where the line is emitted
4. Pilot implementation possible
CIELO VO implementation
CIELO-AGN is the first astrophysical line catalogue compatible with the (draft) IVOA Line Data Model and
accessible through the (draft) Simple Line Access Protocol
(IVOA Line Data Model: Dubernet, Osuna et al., in prep.)
(Simple Line Access Protocol: Salgado et al., in prep.)
Conclusions
High-resolution spectroscopy IS fundamental to understand the physical properties of the gas in the AGN circumnuclear environment (as high-resolution imaging IS fundamental to unveil its true location)
CIELO unveils a criterion to discriminate between AGN- and starburst-dominated sources on the basis of the OVII(f)/OVIII ratio
In obscured AGN, CIELO unveils mounting evidence for
Dominant role of AGN-photoionization,
Important role of resonant scattering,
Broadly constant ionisation parameter ...
on scales as large as a few hundreds parsec
The VO is almost ready to be a tool for scientific investigation in this field.
Stay tuned!