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OJ 287 during two XMM
observations in 2005 and
coordinated WEBT Campaign
A first XMM-Newton
ESA satellite (here a XMM-Newton
fold-out picture) observation of OJ 287 was performed in April 12,
2005, and a second observation performed in Nov. 03-04, 2005. A multiwavelength (mainly
radio-optical) intensive and
short observing campaign composed of two parts (around the satellite
observation dates) was proposed to the WEBT
international collaboration by Stefano Ciprini (Tuorla
Obs. & ENIGMA
Network). Intensive observations by the WEBT and ENIGMA member Institutes were
performed in April and November 2005 during
the two XMM-Netwon pointings, while a normal monitoring by
several observatories was still performed in the following weeks. The teams of the ENIGMA
Network are contributing to both this short-term/intensive campaign
and to the long-term monitoring of the source
in the framework of the "OJ 287 2005-2008 Project".
The second XMM-Newton
observation of about 51 ksec was scheduled during November
3-4, 2005. Intra-night observations by the WEBT (WEBT + ENIGMA
members and who is interested in) were requested
during the days Nov. 2-3-4-5, 2005 (XMM satellite
pointing: Nov. 3-4), and during the Effelsberg radio
mini-campaign: Nov.8-9-10, 2005. Daily (one point per night) observations during
the October-November months by the ENIGMA network teams are welcome.
OJ 287 was optically bright (mag.
R~13.6/13.4), during these observations.
Target |
RA |
Dec |
Position_Angle |
OJ 287 |
08:54:48.87 |
+20:06:30.6 |
104:13:22.6 |
XMM Obs_Duration |
XMM Obs: Start
Time |
XMM Obs: End
Time |
Satellite Revolution |
IB |
51000 sec |
2005-11-03 at
20:59 UT |
2005-11-04 at
11:09 UT |
1081 |
E3 |
The XMM-Newton observations are requested to study the spectral and temporal
behaviour of OJ 287, on both short and long time scales, before
and during the
next probable outburst. Our goal is to clarify the basic physics, and the
relevance of geometrical and energetic (SSC) models in the
interpretation of
long/short-term variability, during both the quiescent and outburst
phases. We aim at comparing data and results on this probably
quiescent phase of OJ 287 during 2005, with observations that we
will propose also during the expected outburst phase, in order to search for
correlations and precursory events. Dedicated
bi-montly VLBA observations of this blazar in 5 bands
from 2005 to 2008 are performing and scheduled. X-ray data will provide
information on the high-energy spectral component (likely inverse
Compton emission), while radio-to-optical observations will map the
behaviour of the synchrotron emission component. These data
will be compared also with the long term observations, to span a
large range of
variability timescales at different electromagnetic frequencies. intraday
optical-radio observations will be very useful around the satellite
pointing, in particular high-precision and high-sampling
observations by
Effelsberg 100m
radio-observatory are recommended during the
day of the XMM pointing (and possibly during the 4 days of the
core campaign). OJ 287 was pointed in January also by the MAGIC
gamma-ray Cherenkov telescope (total time 10h). One global 3mm-VLBI
session will be performed after October 2005. MAGIC
ToO
observations are scheduled around the XMM pointing date.
Latest News:
NEW: A new photometry-polarimetry
programme is started (PI: J. Heidt & K. Nilsson)
NEW:
A 3rd XMM-Newton
observation (48ksec, ~13h)
is scheduled in Nov.17, 2006. More
information will be added later. (PI: S. Ciprini)
MAGIC
ToO observations of OJ 287 performed in Nov.1-4
and Nov. 10-13 (PI: L. Lindfors).
Effelsberg 100m
radio flux/polarization intraday observations
of OJ 287 scheduled on Nov.8-9-10, 12h per day, (PI: L. Fuhrmann).
Part2 core campaign (intraday
observations recommended):
November 2-3-4-5 (priority to November 3-4, XMM-Newton satellite pointing time)
November 8-9-10 (epochs of the radio intraday observations
"Effelsberg mini-campaign")
XMM-Newton observations performed:
second half of the pointing affected by high-background radiation
(solar wind storm, earth proton belt radiation) and ~20% of time
lost. Anyway the long pointing time allowed probably to have still
good data. Simultaneous ground-based optical observations partially
obstructed by bad weather.
Part 2 (Oct. - Dec. 2005): Participating
Observatories
Institutes/Observatories and contact-person(s) -
list
updated by June 27, 2006:
Osaka University
- Osaka, Japan (K. Torii)
Osaka Kyoiku University
- Kashiwara, Osaka, Japan (K. Sadakane, M. Kamata)
Sobaeksan
KASI Optical Astronomy Observatory - Sobaeksan, Korea
(C.-U. Lee)
Lulin Observatory - Lulin,
Taiwan (W.-P. Chen)
Tsinghua University
- Beijing, China (J. Li)
Xinglong Station of NAOC
- Yanshan Mountains, China, (J.-H. Wu)
ARIES Sampurnanand Telescope -
Naini Tal, Uttaranchal, India (R. Sagar, G.
Krishna)
Mount
Maidanak Observatory, Ulugh
Beg Astronomical Institute - Mount Maidanak, Uzbekistan (M.
A. Ibrahimov)
Abastumani Astrophysical Observatory
- Mt. Kanobil, Georgia, (O. Kurtanidze)
Crimean
Astrophysical Observatory - Nauchny, Crimea, Ukraine (Y. Efimov,
V. Larionov)
Çanakkale
Onsekiz Mart University Observatory
- Çanakkale, Turkey (A. Erdem)
Saint Petersburg State
University Observatory - St. Petersburg, Russia (V. M. Larionov)
Bulgaria National Astronomical Observatory
- Rozhen, Bulgaria (E. Ovcharov, A. Kostov)
Jakokoski
Observatory - Jakokoski, Finland (P. Pääkkönen)
Tuorla Observatory
- Piikkio, Finland (L. Takalo, A. Sillanpää)
MonteBoo Observatory, Masaryk University
- Brno, Czech Republic (F. Hroch)
Catania Observatory
- Catania, Italy (A. Frasca)
Campo
Imperatore Observatory - Assergi, L'Aquila, Italy (A. Arkharov)
Armenzano
Observatory - Armenzano, Assisi, Italy (D. Carosati)
Porziano
Observatory - Porziano, Assisi, Italy (D. Capezzali)
Perugia Observatory -
Perugia, Italy (G. Tosti, S. Ciprini)
Torino Observatory - Torino,
Italy (C. Raiteri, M. Villata)
Heidelberg Observatory
- Heidelberg, Germany (L. Ostorero, D. Emmanoulopoulos)
Michael
Adrian Observatory- Trebur, Germany (J . Ohlert)
KVA Telescope - La Palma,
Canary Islands, Spain (L. Takalo, A. Sillanpää)
Nordic Optical Telescope - La
Palma, Canary Islands, Spain (T. Pursimo)
INAOE Tonantzintla Observatory
- Tonantzintla, Puebla, Mexico (O. Lopez-Cruz)
Mt. Lemmon KASI Observatory
- Mount Lemmon, Arizona, USA (C.-U. Lee)
Ohio
University MDM Observatory - Kitt Peak , Arizona, USA (M. Boettcher)
Kitt Peak SARA
Observatory - Kitt Peak, Arizona, USA (J. Webb)
Tenagra Observatories
- Sonoran desert, Arizona, USA (A. Sadun)
National Astronomical Observatory
of San Pedro Mártir - Baja California Peninsula, Mexico (E.
Benitez, D. Dultzin-Hacyan.)
Coyote Hill Observatory - Wilton, Sacramento, California, USA (C.
Pullen)
RATAN-600
(Special Astrophysical Observatory) (576 m) - Zelenchukskaya,
Russia (Y. Kovalev)
RT-22 Crimean Astrophysical Observatory (22m ) - Simeiz, Crimea, Ukraine
(A. Volvach)
Metsähovi Radio Telescope (14
m) - Metsähovi, Finland (M. Tornikoski, A. Lahteenmaki)
Noto Radio Observatory
(32m) - Noto, Siracusa, Italy (P. Leto, C. Raiteri)
Effelsberg
Radio Telescope (100 m) - Effelsberg,
Germany (T. Krichbaum, L. Fuhrmann)
IRAM Millimeter
Telescope (30 m) - Pico Veleta, Spain (T. Krichbaum, H.
Ungerechts)
University
of Michigan Radio Astronomy Observatory (UMRAO) (26 m) - Dexter,
Michigan, USA (M. Aller)
Part 1 (April-May 2005): Participating
Observatories
Institutes/Observatories and contact-person(s) -
list
updated by June 26, 2005:
Osaka Kyoiku
University Observatory - Kashiwara, Osaka, Japan (K.
Sadakane)
Lulin Observatory - Lulin,
Taiwan (W. P. Chen
Xinglong Station of NAOC
- Yanshan Mountains, China, (J.-H. Wu)
ARIES Sampurnanand Telescope -
Naini Tal, Uttaranchal, India (R. Sagar, G.
Krishna)
Abastumani Astrophysical Observatory
- Mt. Kanobil, Georgia, (O. Kurtanidze)
Crimean
Astrophysical Observatory - Nauchny, Crimea, Ukraine (Y. Efimov,
V. Larionov)
Çanakkale
Onsekiz Mart University Observatory
- Çanakkale, Turkey (A. Erdem)
Jakokoski
Observatory - Jakokoski, Finland (P. Pääkkönen)
Nyrölä
Observatory - Nyrölä, Finland (A. Oksanen)
Tuorla Observatory
- Piikkio, Finland (L. Takalo, A. Sillanpää)
Catania Observatory
- Catania, Italy (A. Frasca)
Campo
Imperatore Observatory - L'Aquila, Italy (V. Larionov)
Armenzano
Observatory - Armenzano, Assisi, Italy (D. Carosati)
Perugia Observatory -
Perugia, Italy (G. Tosti, S. Ciprini)
Torino Observatory - Torino,
Italy (C. Raiteri, M. Villata)
Heidelberg Observatory
- Heidelberg, Germany (J. Heidt)
Michael
Adrian Observatory- Trebur, Germany (J . Ohlert)
Agrupacio
Astronomica de Sabadell - Sabadell, Spain (J.
A. Ros)
KVA Telescope - La Palma,
Canary Islands, Spain (L. Takalo, A. Sillanpää)
Nordic Optical Telescope - La
Palma, Canary Islands, Spain (T. Pursimo)
Mt. Lemmon KASI Observatory
- Mount Lemmon, Arizona, USA (C.-U. Lee)
Kitt Peak SARA
Observatory - Kitt Peak, Arizona, USA (J. Webb)
Tenagra Observatories
- Sonoran desert, Arizona, USA (A. Sadun)
Coyote Hill Observatory - Wilton, Sacramento, California, USA (C.
Pullen)
RATAN-600
(Special Astrophysical Observatory) (576 m) - Zelenchukskaya,
Russia (Y. Kovalev)
Metsähovi Radio Telescope (14
m) - Metsähovi, Finland (M. Tornikoski, A. Lahteenmaki)
Noto Radio Observatory
(32m) - Noto, Siracusa, Italy (P. Leto, C. Raiteri)
Effelsberg
Radio Telescope (100 m) - Effelsberg,
Germany (T. Krichbaum, L. Fuhrmann)
IRAM Millimeter
Telescope (30 m) - Pico Veleta, Spain (T. Krichbaum, H.
Ungerechts)
University
of Michigan Radio Astronomy Observatory (UMRAO) (26 m) - Dexter,
Michigan, USA (M. Aller)
NRAO Very Long Baseline Array (VLBA)
- USA (I. Agudo)
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NEW:
Preliminary R-band optical light curve
during the XMM-Newton and WEBT MW campaign (plus the
extended 2005-06 campaign). |
NEW:
Preliminary summary of near-IR
and multiband optical light curves during the campaign. |
November 3-4, 2005: XMM-Newton observations performed:
second half of the pointing affected by high-background radiation. Simultaneous ground-based optical observations partially
obstructed by bad weather.
April 12, 2005: XMM
observations affected by high radiation background and partially stopped due to bad
space weather (a solar flare occurred during the pointing and
only about 4-hours of XMM observing time were possible). Anyway
OJ 287 was detected (here the first raw-image of OJ
287 in X-ray by XMM) and the
extra-time granted will be added to the next pointing in November. Optical ground-based
observations obstructed by bad
weather in Europe in that day. Effelsberg 100-m
radio-observations well carried out.
4-days core and April campaign: rather good optical observations in the other
days of the WEBT campaign. Some radio, optical-polarization and
near-IR data
also available. VLBA & 3mm-VLBI observations on 2 and 17 April. Good
optical monitoring during April by several observatories.
Observing Strategy
Optical observations and data reduction:
Extended campaign: the new season (October 2005 -
April 2006) (ENIGMA
Network teams only and who is
interested in).
We suggest that optical observers perform BVRI
(Johnson's B,V and Cousins' R,I, if possible)
sequences when possible with a R-band additional sequence. For small
telescopes (< 60cm) we suggest to perform R-band only
sequences. Other band (for example U,
and J,H,K) are accepted. The source in October-November is visible
at the end of the night for Europe observers.
WEBT campaign (part1 and part2):
We suggest that optical observers perform a BVRI
(Johnson's B,V and Cousins' R,I, if possible; other
filters are also accepted) sequence at the beginning and/or at the
end of the night, and a BR sequence during all
the available observing night-time hours. When a BR
sequence cannot be performed, we suggest to carry out observations
in the R-band only (this last choice is recommended to small
telescopes). This allows us to get simultaneous light curves
in B and R bands for optical spectral variability studies too. Then
a 4-days period will allow to search for possibly short lags between
X-ray and radio-optical emission.
The brightness of OJ 287 (out of the cyclical outbursts phases) is
about mag(R)= 16 - 13.5, and most telescopes should be able to
provide data a rather good S/N in exposures. Please remember that for variability analysis the precision on
the observations (frames) times is important as the photometric
precision (correct UT synchronization is possible looking for
example at the at USNO
clock especially during the core campaign). Other data and
information useful for the observations are online in the USNO
DataServices and Staralt
web pages.
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Data will be collected as instrumental magnitudes of the source and reference stars, in order to apply the same analysis and calibration procedures to all datasets. The suggested data format
is in tables separated for each filter with rows as in the
example below:
JD-2452000 |
OJ 287 |
4 |
10 |
11 |
C1 |
C2 |
1067.43408 |
14.362 0.005 |
14.382 0.008 |
14.370 0.030 |
14.461 0.060 |
14.622 0.060 |
14.703 0.070 |
where JD (or equivalent date + UT)
must be geocentric at mid exposure. Times are requested with second
precision (e.g. 2003 10 01 00 00 01, or the preferred corresponding
JD - 2452000 = 913.50001 with five decimal digits); mags and errors
should have three decimal digits. Observers are requested to perform
bias/dark correction and flat-fielding on their frames, and to
obtain the instrumental mags with some procedure. Both aperture
photometry (possibly using IRAF or CCDPHOT) or Gaussian fitting are
allowed. In the case of aperture photometry, we suggest that all
observers use the same parameters, i.e. 8, 13, and 18 arcsec for the
radii of the aperture and of the edges of the sky annulus. However,
the sky annulus radii can be seeing-dependent in order not to
contaminate the sky region with source flux.
Data format
recommendation: we strongly encourage the observers to provide data in the exact format
specified above. The adjustment of numerous
different formats is a time-consuming work, it can induce errors and it delays the analysis
and publication of results.
OJ 287 is a pure BL Lac object, therefore optical polarization
measurements are very important too.
Near-IR Observations
Observers having access to infrared telescope facilities, are invited to contribute
with infrared observations in the same way specified for the
optical strategy. Our
finding chart + magnitude table also contains the J, H,
K mag of comparison stars adopted.
Radio Observations
During the campaign multiband radio flux
(priority) and polarization measurements are
important. The strategy is the same
mentioned above for the optical observers.
Contacts
All observers interested in participating in this campaign are
invited to send messages and data to the following 3 addresses (on
the same email):
- this Campaign Manager (S. Ciprini: stefano.ciprini<at>utu.fi)
- the WEBT President (M. Villata: villata<at>to.astro.it)
- one of the OJ 287 2005-2008 Project Managers (L. Takalo: leo.takalo<at>utu.fi)
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