README web version of /home/usg/OPS/MTS/readme_xml/readme_77083501

Principal Investigator Email Address

• linz@mpia-hd.mpg.de

Estimated Total Execution Time (hours, including overheads)

• 2

General Description

• This is a small observing program to image two regions of massive star
   formation with maser association.
  Both regions will be imaged in the same three filters: PAH1, PAH2_2 and Q2.
  The goal is to trace the spectral energy distribution of the compact objects associated
   with the masers.
  Furthermore we want to see, if secondary sources in the immediate vicinity (2-3
   arcsec) exist, that
  could not be distinguished by the modest spatial resolution of the Spitzer satellite
   imaging.
  
  From the IR satellites, we have a few basic information about the two regions:
  
  IRAS 18566+0408: The target is expected to be the strongest source in the Visir
   FOV. It seems, the local
                   maser is associated with the IRAS source itself. IRAS reports 14
   Jy at 12 micron, 
                   but the IRAS and the ISO spectrum show a deep and broad silicate
   absorption feature at 
                   9.7 micron. According to the ISO spectrum, the flux at 8.6 micron
   is just 3.2 Jy.
                   Furthermore, these are all low spatial resolution satellite data,
   but we are
                   interested in the small scale structure ... perhaps it breaks up
   into several entities.
                   No high spatial resolution imaging at infrared wavelengths is available
   for this source.
                   The Spitzer IRAC data are degenerated at the source location at
   5.8 and 8.0 micron (also
                   because of strong PAH band contributions in the Spitzer filters),
   so
                   the actual brightness distribution in the inner 2-3 arcseconds
   is unclear up to now
                   - an item we want to investigate.
  
  IRAS 18324-0820: Here, a bright and somewhat extended UCHII region is located 15
   arcseconds to the 
                   southwest. The interesting source is still weak at 8 micron (probably
   between 20 and 40
                   mJy). It should not be mixed up with a somewhat brighter source
   that is located roughly 
                   7.5" to the west and 3.5" to the south of the actual maser IR counterpart
   (see 
                   finding chart). The region 10 arcseconds to the northeast of the
   maser source seems to
                   be a little bit less affected by the ubiquituous extended emission
   in the entire
                   region, so this seems to be a good place to chop and nod to ...
   Therefore I hope that
                   the standard setting for chop/nod (10 arcsecs throw, chopping angle
   0 degrees) is a
                   good choice here.
  
                   Since we realised now, that the source is not bright enough for
   the acquisition,
                   we will use a bright source at 78.8 arcsec away from the science
   target to blindly
                   offset from this source (2MASS coordinates: 18 35 09.322,  -08
   16 34.28  J2000).
                   That bright source should be brighter than 3 Jy in the N-band ...
                   
                   We removed the PAH1 filter from the original OB and do now longer
   integrations
                   in the PAH2_2 and Q2 filters. 
  
                   In the meantime, the Spitzer/MIPSGAL 24 micron data got public
   and confirm that
                   the target increases in brightness toward longer wavelengths. At
   24 micron, the
                   flux is around 450 mJy, hence, a wild guess for the flux in the
   Q2 band filter 
                   would be around 200 mJy, thus, still somewhat faint.

Waiver Requests

• No Waiver Request was submitted

Critical Observing Condition Constraints

• We just mention the truism that in particular Q band observations (but
   also N band observations to a
  lesser extent) would suffer from medium to high humidity in the atmosphere. In the
   constraint set, it is not 
  foreseen to give a limit on this parameter, so we just mention it here as a general
   remark.

Time-Critical Aspects

• none

Special Execution Requirements

• none

Special Calibration Information

• We will rely on the standard ESO calibration plan for Visir. 
  However, this proposal includes Q band observations and we would be glad if such
   calibrators could be
  chosen over the night that are still sufficiently strong in the Q band to ensure
   a meaningful and
  more or less easy calibration of the science data. Thanks in advance ...

ToO Information

• ---(Empty)---

ToO Activators List

• ---(Empty)---

Is this a Pre-imaging run ?

• false

Pre-imaging Requirements

• ---(Empty)---

Source(s) of Pre-imaging

• ---(Empty)---

Pre-imaging sources not listed above

• ---(Empty)---

Do all your OBs comply with the instrument-specific requirements listed
 on the instrument-specific Phase 2 web page ?

• YES

If this is a pre-imaging run, did you select PRE-IMAGING for the Observing
 Category for each Observing Template ?

• N/A

Do all your finding charts comply with both the general and instrument-specific
 Phase 2 Web Pages ?

• YES

If you submitted OBs for standard stars, did you specify the magnitude
 and spectral type of all standard stars in the OBs ?

• N/A

Have you included OBs for any calibrations that you need but which are
 not part of the Calibration Plan ?

• N/A

If you are observing Moving Targets, have you attached suitable ephemeris
 files to your OBs?

• N/A

If you have preferences which OBs should be executed first, did you make
 use of the User Priority field in the OBs ?

• N/A

If this is a run that requires coordinated observations with other facilities,
 did you give proper instructions in the Time-Critical Aspects Section ?

• N/A

If the provided finding chart is at a different wavelength than the observations,
 did you clearly describe in the README file how to identify the target?

• N/A

Did you specify a guide star brighter than V=12mag within a field of
 r=5arcmin around the science target?

• YES