Prezentace aplikace PowerPoint

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Identification of INTEGRAL Sources with
Astronomical Archival Plates(and by CCD imaging)

R. Hudec, F. Munz, J. Štrobl, P. Kubánek, P.
Sobotka, R. Urban
Astronomical Institute, Academy of Sciences 251
65 Ondrejov, Czech Republic ISDC, Versoix,
Switzerland IBWS Oct 25-28, 2006
v
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• Identification of Sources
• Only a fraction of 209 sources seen by INTEGRAL
  are either known sources or have been identified
  and classified already.
• From the 56 newly by INTEGRAL detected sources
  (IGR sources), only 20 have already firm
  classification, mostly with Cataclysmic variables
  (CVs), AGN, High Mass X-ray Binaries, Low Mass
  X-ray Binaries, Black Hole Candidates, and
  Anomalous X-ray Pulsars (Bird et al. 2006).
• One of the methods applied in the past is the
  identification by optical spectroscopy, which
  proved recently some new and interesting
  identification of INTEGRAL gamma-ray sources such
  as newly detected symbiotic and cataclysmic
  variables (e.g. Masetti et al., 2005a, 2005,
  Wheatley et al., 2005).

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• Limitations of Recent Method
• Although successful, this method has some
  limitations.
• it can be hardly applied for particular types of
  transients and recurrent transients.
• it requires access to dedicated large aperture
  telescopes and spectrographs.
• it can be laborious in the case of large error
  box and crowded field.
• in some specific cases, only the spectral
  information alone is not enough for reliable
  classification of the objects.

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• The alternative method
• We propose an alternative method how to identify
  the still non-classified INTEGRAL gamma ray
  sources and newly detected INTEGRAL sources in
  the future (and of other high energy satellites).
  
• This method is based on the fact that (1) many of
  gamma-ray sources identified and classified so
  far do have optical counterparts, in many cases
  brighter than mag 18, (2) a significant fraction
  of these sources is variable both in gamma-rays
  as well as in optical wavelengths, and (3) they
  are in the fields densely covered by archival
  optical observations covering typically years to
  tens of years.
• The results can be used also to confirm the
  classification proposed by spectroscopy and to
  provide additional details for better physical
  understanding of the sources.

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Legend - B 1 2,29 - 5 2 5 -10 3 10 - 15 4 15 - 20 5 20 - 23
Legend - V 1 2,39 - 5 2 5 -10 3 10 - 15 4 15 - 20 5 20 - 21
Optical B and V magnitudes of optically
identified INTEGRAL gamma-ray sources most are
brighter than mag 20, and more than half are
brighter than mag 15
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• It is not very clear at the moment whether the
  fact that most of the identified sources are
  brighter than mag 15-20 is due to the fact that
• The non-identified sources are optically fainter
  than mag 20
• or
• They are brighter than mag 20 but remain
  non-identified because of lack of observational
  data/identification efforts. The recent
  identifications of CVs and SSs by Masetti et al.,
  2005, 2006, indicate that at least for some
  fraction of the sources this is may be true.
• Surely, the selection effect plays a role since
  so far, the mean-class telescopes have been used
  to identify the sources

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Archival sky patrol plates

• There are more than 3 millions archival plates in
  the world, lim mag up to 23, gt 5 x 5 deg in most
  cases
• Suitable for dense long-term photometry (up to
  100 years, up to 2000 points, up to 23 mag)
• Suitable to detect rare events - years od
  CONTINUOUS monitoring easily possible
• Use of scanners, powerful computers and
  innovative software allows the effective data
  extraction and evaluation for the first time

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Various types of astronomical plates
(digitised) automated analyses with novel
algorithms - task mainly for informatics students
Multiple exposure
Spectral image Direct Image
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Suitable Databases for INTEGRAL

• The Sonneberg Field Patrol and Leiden/Johannesburg
  Franklin Adams Plates represent suitable
  database for identification and analysis of
  INTEGRAL sources
• They both provide numerous data for regions along
  the Galactic Plane and in the Galactic center

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Sonneberg Field patrol

• Northern regions along the Galactic Plane (but
  also other fields) covered by numerous (typically
  50500) astrograph plates. Typical Field of View
  (FOV) is 10 x 10 deg and the typical limiting
  magnitude is B 17.
• In exceptional cases, also low-dispersion
  spectral plates are available

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Leiden/Johannesburg Franklin Adams Plates

• These plates were taken in Johannesburg by the
  high quality Franklin Adams refractor (Taylor,
  1904) in years 1923-1952 within the project
  originated by Prof. E. Hertzsprung and are
  located in Leiden.
• The plates cover selected fields along the
  southern Galactic plane as well as the Galactic
  centre.
• The typical number of plates per field is
  300400, FOV is 10 x 10 deg and limiting
  magnitude 17.

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UKSTU Plates (ROE, UK)
The deepest astronomical plates in the world

• faint limits, mag 19 - 23
• FOV 40 sq. degrees
• various colors/filters
• spectral plates down to mag 18
• 18 000 plates over 30 years
• Unfortunately end of operation in 2001

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Digitized Schmidt plate, TLS Tautenburg, lim mag
20, field M92. Newly detected variable objects
with light amplitude gt 2 mag are indicated.
Example of the use of the powerful computer and
novel dedicated software on digitised plates.
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Analogous study can be also performed by CCD
imaging monitoring. On CCD images separated in
time by weeks to years, the variable objects can
be easily found. This is suitable for searches
for objects with variability scales less than one
year We have started to monitor the IGR positions
by robotic telescopes and, more recently, by a 60
cm CCD telescope at the Brno Observatory
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Monitoring of IGR sources by robotic CCD
telescopes BART and WATCHER
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The proposed analysis

• Using the data mentioned here, the optically
  identified INTEGRAL sources with objects brighter
  than mag 17 can be investigated for long-term
  changes covering 10 50 years.
• In addition, these data can be used to search for
  new optical identifications of non-classified
  INTEGRAL sources on hand of their optical
  variability. This has been used already
  succesfully for ROSAT (Greiner and Richter,2006)

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Distribution of Sonneberg Field Patrol Fields and
Franklin Adams Fields (blue) in Galactic
coordinates.The densely covered fields are
darker.
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The coverage of INTEGRAL IBIS for revolutions 1 -
430.
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• Additional prospects
• analyzing the light curves for flares and flaring
  activity like these seen in V1223 Sgr and TV Col
• trying to fit the flare profiles
• trying to look for possible periodicities and
  recurrence
• study of colors and color changes with time, with
  consequent physical discussions and
  interpretations.
• correlations with other objects, with related
  conclusions toward physical processes and
  physical models.

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Optical analyses of INTEGRAL gamma ray sources

• Promising task for our group, taking into account
  our facilities and our experience
• Also for other HE satellites and observing
  campaigns
• Examples LSI 61 303 mag 10, optical counterparts
  of fast X-ray transients-massive stars, INTEGRAL
  CVs and symbiotics, etc.

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TV Col is an intermediate polar (IP) and the
optical counterpart of the X-ray source
2A0526-328 (Cooke et al. 1978, Charles et al.
1979). This is the first cataclysmic variable
(CV) discovered through its X-ray emission. TV
Col displays three types of variation in the
optical (a) basic 0.2163 d photometric
variation with an amplitude of 0.27 mag (Motch
1981). (b) spectroscopic period of 0.22868 d
(Hutchings et al. 1981). (c) beat period of 4.024
d between the photometric and spectroscopic
period (Motch 1981). (d) flickering (0.1 mag) on
the time scale of minutes or dozens of minutes
(Motch 1981). (e) brief outbursts lasting for
hours with an amplitude of 2 mag (Szkody and
Mateo 1984).
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Photographic light curve of TV Col including
segments densely covered by the observations. The
detected outbursts are marked by the vertical
lines. The data are connected by the line in the
densely covered intervals for convenience. The
photographic magnitudes were calibrated to the B
magnitudes. The empty triangles denote the upper
limits of brightness.
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Outbursts of TV Col Date JD
Max. (mag) Duration
Source 2434420.348 B12.60
lt1 day Hudec et al. 2005 2434475.265
B13.29? lt 1 day Hudec et
al. 2005 2439031.625 B13.38
lt 1 day Hudec et al. 2005 2439059.510
B12.33 lt 1day Hudec et
al. 2005 2440572.398 B12.25
lt1 day Hudec et al. 2005 2444295.819
V12.3 3 hr, 1 d Szkody and
Mateo (1984) 2446125.73 V11.9
4.5 hr Schwarz and Heemskerk
(1987)
2446133.50 V12 6 hr
Schwarz and Heemskerk (1987) 2447122.6
DB1.2 6 hr
Augustein et al. (1994) 2447125.7
DB1.8 6 hr Augustein
et al. (1994) 2447133.6 DB1.8
8 hr Augustein et al.
(1994) 2448600.375 V12.4 6
hr, 3d Hellier and Buckley
(1993) Note corresponds to the full decline
of outburst.
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Decay time scale of dwarf nova (DN) outbursts tD
(in days/mag) versus the orbital period Porb. The
solid line marks the fit to non-magnetic DN
(empty circles) (Warner 1995). Intermediate
polars are denoted by the solid circles. The
upper and lower symbols for HT Cam mark the
initial and final tD, respectively. The outburst
data for IPs come from Hellier et al., (1997),
Ishioka et al. (2002), Schwarz et al. (1988),
Šimon (2000, 2002), van Amerongen and van
Paradijs (1989), Warner (1995).
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• Conclusions
• Alternative identification method based on high
  quality astronomical archival plates has been
  proposed
• In addition, already identifies sources can be
  effectively monitored in optical light
• Important also for searches for brightenings in
  IBIS data

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The End