README web version of /home/usg/OPS/MTS/readme_xml/readme_81053000

Principal Investigator Email Address

• isaviane@eso.org

Estimated Total Execution Time (hours, including overheads)

• 30:06:35

General Description

• This program aims at obtaining relatively high signal to noise spectra
   (S/N>~18@1638.1) for a sample of 5 very red stars in the Fornax dSph
  (named Fornax 1, Fornax 2, etc..). 
  
  These stars are candidate AGB stars in the process of expelling their dusty envelope.
   Several atomic (FeI, CaI, SiI) and molecular (CO,OH) 
  lines will be measured in the CRIRES spectra in order to get accurate abundances
   of Fe, C, O and other alpha-elements.
  The [alpha/Fe] abundance ratio will give constraints on the global metallicity (iron
   + alpha) and the relative SNII/SNIa contribution to the enrichment of the proto-gas
   from which these stars formed and the overall timescale. 
  The C/O abundance ratio will allow us to classify these objects as oxygen-rich or
   carbon-rich stars. This
  classification will be the first step towards the creation of a complete census
   of AGB star subclasses in LG dwarfs,
  with the aim of calibrating the C-star fraction vs. mean metallicity and star-formation
   history.
  
  
  The total time on target required to obtain S/N>18 @ 1638.1 is ~4hr. 
  This will be obtained through 12 nodding cycles (DIT=600s). 
  For each target, 6 OBs of 54min execution time have been created 
  (40min integration time each, named Fornax 1, Fornax 1-0, Fornax 1-1, etc..).
  Eight OBs were created only for the faintest target (Fornax 3). 
  Each OB contains 2 nodding cycles. Whenever the schedule would allow for 
  the observation of more than one OB of the same target in a row, please, 
  do the acquisition only for the first OB. This would save time. Alternatively, 
  the number of cycles in the science OBs can be increased.
  
  Once started, please complete all the OBs for one star before moving to the next
   target.
  
  OBs have been submitted for the telluric standard HIP012387.
  If possible, observe it once per night every time science OBs are observed, 
  possibly soon after or before the science observations.
  A total of 7 OBs were submitted for the standard star (total execution time 1:18hr).
  HIP012387 is a O star (H_OBJ=4.74). The allowed spectral range is O0-O9. 
  We require S/N~100@1638.1nm (1.5min integration time: 1 nodding cycles, 
  DIT=45; 11min execution time per OB).
  
  We will consider the program executed within constraints
  even if a science OB will not be accompanied by a telluric standard
  OB in the same night. This is why the number of calibration OBs 
  is less than the number of science OBs.

Waiver Requests

• A waiver request was submitted and approved to allow for a slit width
   of 0.8arcsec.
  Our targets are relatively faint (H=14), therefore a large slit width is needed
   to avoid light loss and 
  minimize the time on target needed to obtain S/N>18 @ 1638.1nm. 
  
  The proposal was originally submitted for visitor mode and then moved to Class C
   - filler, by the OPC.

Critical Observing Condition Constraints

• no critical observing constraints

Time-Critical Aspects

• no time critical aspects

Special Execution Requirements

• no special execution requirements

Special Calibration Information

• OBs have been submitted for the telluric standard HIP012387.
  If possible, observe it once per night every time science OBs are observed, possibly
   soon after or before the science observations.
  A total of 7 OBs were submitted for the standard star (total execution time 1:18hr).
  HIP012387 is a O star (H_OBJ=4.74). The allowed spectral range is O0-O9. 
  We require S/N~100@1638.1nm (1.5min integration time: 1 nodding cycles, DIT=45;
   11min execution time per OB).

ToO Information

• not a ToO program

ToO Activators List

• ---(Empty)---

Do the README file and the instrument comments of the telluric stars
 OBs include the required S/N/pixel of the spectrum of the telluric star, its spectral
 type and allowed spectral range?

• YES

Do any OBs include wavelength or flatfield calibrations?

• NO

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

• N/A

If the slit viewer guide star is different from the target, are the RA
 and DEC offsets accurate to within 0.05 arcsec and do they take into account the
 relative proper motion between the two objects?

• N/A

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

• N/A