This section describes relevant changes for observations to take place during Period 100.

General

• During Period 100, the ESO time slots are expected to be scheduled from 27 July to 9 August, and from 22 September till 1 October. Due to major maintenance activities on the telescope, there will be no science observations from October 2017 till March 2018.
  
• The exact distribution of the observing time between the APEX partners can be found on the APEX web pages. Time-critical observations should only be requested during the ESO runs.
• Large and Monitoring programmes will only be accepted for ARTEMIS and SEPIA.
  

Instruments

• ARTEMIS has been offered since Period 98. In Period 99, both the 350 and 450 μm channels are offered for simultaneous observations. This instrument is optimized for wide-field mapping of areas of at least 4'x2', and achieves similar mapping speeds at both wavelengths. An observing time calculator is available.
  
• SEPIA can house up to 3 ALMA-type receiver cartridges.
  
  • Since Period 99, two receivers are available: a band 5 receiver, covering 159 to 211 GHz with dual polarization, sideband-separating mixers (2SB), and a band 9 receiver, covering 600 to 722 GHz with dual polarization, double-sideband mixers. Both receivers are available for normal, Monitoring and Large Programmes.
  • In the course of 2018, the band 9 receiver will be upgraded with 2SB mixers, and a new dual polarization 2SB band 7 receiver (260 to 370 GHz) will be installed.
    
  • Both band 5 and 9 receivers use the XFFTS backends, covering 4 GHz IF bandwidth. In the 2SB receiver of band 5, both bands are recorded, while in the DSB receiver of band 9, only one band is recorded. In both cases, there is a gap of 8 GHz between the image and signal bands. An observing time calculator for both bands is available.
• SHFI: all 3 receivers are offered in Period 100. These may be superseded in 2018 with the planned installation of new receivers in SEPIA and FLASH. Hence, no Large or Monitoring programmes on SHFI will be accepted in Period 100.
  
• FLASH:
  
  • This PI instruments is offered to the ESO community on a collaborative basis with MPIfR. Large programmes or time critical observations with PI instruments will not be accepted. Users who would like to use FLASH must contact the instrument PI, Dr. Rolf Guesten (rguesten[AT]mpifr-bonn.mpg.de), at least two weeks prior to submitting their proposal. Members of the PI team should be included as CoIs on the proposal. The operation of these PI instruments requires the presence of the instrument team so all ESO FLASH and observations will be scheduled on fixed dates; the exact dates have not been determined yet.
  • Observations will be done by the PI team during a maximum of 3 days. Preference will be given to proposals using the dual-beam, wide-bandwidth capabilities of FLASH due to limited ESO observing time.
• CHAMP+: This MPIfR PI instrument is not offered in Period 100 due to a planned technical intervention. It may be offered again in Period 101.
• SABOCA is not offered in Period 100 as the same capabilities are offered by ARTEMIS.