README web version of /home/usg/OPS/MTS/readme_xml/readme_79030700
Principal Investigator Email Address
Estimated Total Execution Time (hours, including overheads)
General Description
This is a combined imaging and spectroscopic programme with the goal to
characterise the circumstellar disks around very close (separations between 0.07
and 3.0") pre-main-sequence binaries and triples in Ophiuchus. 28 sources (incl.
Galactic Center for calibration) are observed in the K-band, 21 in the L-band, and
13 with K-band spectroscopy.
Instrumental Setup: We will use NACO in it's imaging mode in the K-band and the
L-band as well as its spectroscopic mode S27_3_SK! Since they offer the smallest
pixelscales, the cameras S13 (K-band), L27 (L-band), and S27 (spectroscopy) are
utilised.
Imaging: The reference sources for the AO-system are the binaries/triples or one
of their components. They should be centered during the acquisition. Afterwards,
a series of generic offsets shifts the binaries to all four quadrants of the detector.
This method leads not only to a satisfying background subtraction, but also allows
to cover a reasonable large area around each primary to search for new companions!
Since we are interested in the absolute and relative fluxes of the components, it
is important to operate the detector in its linear range. Therefore, the DIT in
the science template is chosen in such a way that we expect to be well inside this
regime. However, the sources are highly variabel and thus the estimated DIT should
be checked carefully by the night astronomer. This can easily be done by using the
acquisition exposure, that will be obtained with the same DIT specified for the
science images! If the DIT in the science template has to be decreased significantly,
please increase the number of NDITs (without increasing the total execution time
of the OB) to compensate at least partially the sensitivity loss.
In the L-band chopping is used with exception of two sources that are too bright
and thus require a neutral density filter! In these cases chopped images are also
taken to determine the effect of the neutral density filter with the help of the
companion.
Spectroscopy: The slit orientation as indicated by the dashed thick line in the
finding chart (given value is the PA of the companion; the slit orientation differs
by 180 deg when PA > 180 deg) has been chosen with the aim to bring both components
of a binary into the slit. However, due to the orbital motion of the companions
it may be necessary to adjust the slit positions! IMPORTANT: Two slit orientations
are required for each of the two triple systems. In the case of ROXs16 a position
angle of ~24deg brings the close companion (0.1") and a position angle of ~105 deg
the wide companion (0.6") together with the primary into the slit. The two components
of the binary (0.1") orbiting L1689-IRS5 can be brought individually together with
the primary into the slit by position angles of ~240 deg and ~240+-5 deg. The exact
PAs of the companions in the tripel systems have to be determined during the acquisition.
Moreover, it is highly recommended to execute the two OBs associated to each of
this triple systems, i.e.
ROXs16S_1of2 & ROXs16S_2of2
L1689-IRS5S_1of2 & L1689-IRS5S_2of2 (identical, same position angle set for
both companions)
consecutively, so that the night astronomer can use for the second OB her/his knowledge
about the relative positions of the sources and the instrument settings found. Especially
in the case of L1689-IRS5 this approach is essential, because otherwise it cannot
be ensured that the observations are not redundant (position angle for both companions
around PA ~ 240 deg). It is not unlikely that all three components of L1689-IRS5
can be brought into the slit. Then the second OB (L1689-IRS5S_2of2) can be skipped.
Waiver Requests
Critical Observing Condition Constraints
Time-Critical Aspects
Special Execution Requirements
Special Calibration Information
No additional OBs for PSF-references have been submitted. To calibrate
the pixelscale and the orientation of the detector we include an observation of
the Galactic Center named "CAL_GCIRS7". Since we use the Ks-band and the L'-band
filter for photometry, standards are observed within the calibration plan. The achieved
accuracy is sufficient. We will clean the K-band spectra by using the telluric standards
taken within the calibration plan.
ToO Information
ToO Activators List
Is this a Pre-imaging run ?
Pre-imaging Requirements
Source(s) of Pre-imaging
Pre-imaging sources not listed above
Do all your OBs comply with the instrument-specific requirements listed
on the instrument-specific Phase 2 web page ?
If this is a pre-imaging run, did you select PRE-IMAGING for the Observing
Category for each Observing Template ?
Do all your finding charts comply with both the general and instrument-specific
Phase 2 Web Pages ?
If you submitted OBs for standard stars, did you specify the magnitude
and spectral type of all standard stars in the OBs ?
Have you included OBs for any calibrations that you need but which are
not part of the Calibration Plan ?
If you are observing Moving Targets, have you attached suitable ephemeris
files to your OBs?
If you have preferences which OBs should be executed first, did you make
use of the User Priority field in the OBs ?
If this is a run that requires coordinated observations with other facilities,
did you give proper instructions in the Time-Critical Aspects Section ?
If you have PSF reference star OBs, do the names of those OBs begin with
PSF_ ?
If there are Finding Charts attached to your OBs, is the field-of-view
of at least one of these charts 2' x 2' (with clearly labelled field orientation)
?
Have you clearly marked and labelled your wavefront reference objects
R1, R2, R3, ... (as specified in the NAOS Preparation Software) on your Finding
Charts ?
Have you specified the magnitude of the brightest object in the field-of-view
for each OB ?
Are there objects in any of your fields (including standard stars) which
are brighter than the limits specified in the User Manual and on NACO web Pages
?
If the previous answer is yes, have you given a list of OBs and a justification
for the brightness limit violation in the general description field ?
Last creation of page: Tue Oct 6 15:40:18 2009
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