This section describes relevant changes for observations to take place during Period 102.

General

• In order to prepare APEX for continued operation until the end of 2022, the telescope is undergoing major maintenance activities from September 2017 to March 2018. The telescope is expected to resume science operations by mid-April 2018, after the completion of the re-commissioning activities. Until the completion of these activities, the ESO time slots are subject to changes. The preliminary dates are 29 July to 11 August and 23 October to 12 November.
• The ESO share in the APEX collaboration has increased from 27% to 32%. The exact distribution of the observing time between the APEX partners can be found on the APEX web pages.
  
• Large and Monitoring programmes will only be accepted for ARTEMIS and SEPIA.
  

Instruments

• ARTEMIS: in Period 102, 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 3 ALMA-type receiver cartridges.
  
  • Since Period 101, three receivers are available:
    
    • a band 5 receiver, covering 159 to 211 GHz with dual polarization, sideband-separating mixers (2SB),
      
    • a new band 7 receiver (272 to 376 GHz) with dual polarization, sideband-separating (2SB) mixers,
    • a band 9 receiver, covering 600 to 722 GHz with dual polarization, double-sideband mixers (DSB).
      
  • Only the band 5  receiver is available for Monitoring and Large Programmes.
  • The band 7 receiver is offered conditional to a successful commissioning in March 2018, and replaces the SHFI/APEX-2 receiver.
    
  • The band 9 receiver will be upgraded with 2SB mixers over the course of 2018.
  • All receivers use the XFFTS backends, covering 4 GHz IF bandwidth. In the 2SB receiver of band 5 and 7, 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 all bands is available.
• PI230:
  
  • This new 230 GHz receiver covering 200 to 270 GHz is offered as a replacement of the SHFI/APEX-1 receiver.
    
  • It is a dual polarization, sideband-separating (2SB) receiver with an IF coverage of 8 GHz per sideband. There is a gap of 8 GHz between both sidebands.
    
  • The backends are 4th generation Fourier Transform Spectrometers (FFTS4G) with 2x4 GHz bandwidth.
    
  • A more detailed description is available in the presentation "A-MKID, PI-230, LAsMA - new MPIfR receivers for APEX".
    
  • An observing time calculator for both bands is available.
    
• CHAMP+: This MPIfR PI instrument is not offered in Period 102 because of ongoing re-commissioning activities.
• FLASH This MPIfR PI instrument is no longer offered, as during the 2nd half of 2018, it will be replaced by a new instrument (nFLASH) which will contain a band 6 (200 to 270 GHz) and band 8 (385 to 500 GHz) receivers.
• SHFI was decommissioned in September 2017. The APEX-1 receiver has been replaced by the PI230 instrument, and the APEX-2 receiver by the band 7 receiver of SEPIA. The APEX-3 receiver will be replaced by a new receiver inside the nFLASH instrument, and is expected to be offered in Period 103.