README web version of /home/usg/OPS/MTS/readme_xml/readme_82021300

Principal Investigator Email Address

• ez@astro.uu.se

Estimated Total Execution Time (hours, including overheads)

• 08:58:56

General Description

• Background: 
  Tidal dwarf galaxies form out of tidal debris from galaxy mergers, and are therefore
   not expected to contain any significant amounts of non-baryonic dark matter. However,
   rotation curve data have surprisingly revealed the presence of unseen matter components
   in these objects, indicating the presence of dark baryons. Here, we will study the
   integrated VRI colours in the faint outskirts of these tidal dwarfs to search for
   signatures of a halo-like stellar population with a very bottom-heavy stellar initial
   mass function, which would help explain the anomalously high baryonic mass-to-light
   ratios of these systems.
  
  Observations: 
  The goal of this programme is to obtain deep VRI images of three tidal dwarf galaxies
   in the vicinity of the NGC5291 merger. These data will used be derive colour profiles
   of these objects, extending out to very faint surface brightness levels. 
  
  The three target galaxies are located in two different fields: NGC5291N (1 target)
   and NGC5291S (2 targets), 7 arcmin away from each other. 
  
  The OBs will execute sequences of short (10-300s) exposures with offsets (typically
   60-500 arcsec) in between. The shorter exposures will be used to measure the instrumental
   PSF from stars in the frames, whereas the longer ones will be used to derive the
   surface brigthness profiles of the target galaxies. Superflats will be constructed
   from sequences of short (60 s) exposures of a relatively clean sky field close to
   NGC5291, obtained at the end of the OBs NGC5291S_V2+skyflat, NGC5291S_R2+skyflat,
   NGC5291S_I2+skyflat.

Waiver Requests

• No Waiver Request was submitted

Critical Observing Condition Constraints

• Because of the very faint surface brightness levels aimed for, all OBs
   must be executed in dark time. To limit PSF scattering effects, the seeing is restricted
   to be 1.0" or lower.
  
  One OB (NGC5291NS_VRI_calib) requires PHO conditions for photometric calibrations,
   whereas the rest can be executed under CLR conditions.

Time-Critical Aspects

• None

Special Execution Requirements

• The different OBs have been assigned the following priorities:
  
  Priority 1: NGC5291NS_VRI_calib (photometric calibration and PSF measurements in
   VRI of both target fields)
  
  Priority 2: NGC5291S_R1 & NGC5291S_R2+skyflat (R-band imaging of the NGC5291S
   field + sky)
  
  Priority 3: NGC5291S_I1 & NGC5291S_I2+skyflat (I-band imaging of the NGC5291S
   field + sky)
  
  Priority 4: NGC5291S_V1 & NGC5291S_V2+skyflat (V-band imaging of the NGC5291S
   field + sky)  
  
  Priority 5: NGC5291N_R1 (R-band imaging of the NGC5291N field)
  
  Priority 6: NGC5291N_I1 & NGC5291N_I2 (I-band imaging of the NGC5291N field)
  
  Priority 7: NGC5291N_V1 & NGC5291N_V2 (V-band imaging of the NGC5291N field)

Special Calibration Information

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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 ?

• YES

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 you have prepared your finding charts with tools other than FIMS,
 do they comply with the specifications on the FORS1 Phase 2 web page ?

• YES