Atacama Pathfinder EXperiment APEX
Observing with APEX


Observing with APEX


Applying for observing time


  • Technical system summary

    The link above gives a summary of important system parameters for all receivers and backends available at APEX. Currently the following receivers are available:
    Facility receivers: APEX-2A (line, 279-381GHz),
    PI receivers: FLASH (line, 420-495 & 780-887GHz), only available in collaboration with MPIfR staff, contact Rolf Güsten at MPIfR ( before submitting proposals
  • Observing time estimation

    Each proposal must be accompanied by an accurate estimate of the necessary observing time needed to complete the project, based on the required sensitivity and the receiver characteristics.
    The atmospheric transmission at APEX as function of observing frequency and precipitable water vapor can be calculated in the following link .
    There is an observing time calculator for APEX-2a.
  • Proposal submission


    ESO proposal deadlines are set up twice a year, in March and September, for the observing periods 1 October - 31 March and 1 April to 30 September, respectively. Please consult the ESO Proposal Preparation and Submission web page for details.

    APEX contact: Carlos de Breuck, email: cdebreuc(at)

  • Sweden (Onsala Space Observatory, OSO)

    Calls for proposals for swedish time at APEX are announced at OSO's Proposal Guidelines for details.

    APEX contact: Hans Olofsson, email: hans.olofsson(at)


    APEX contact: Rolf Güsten, email: rguesten(at)


    APEX contact: Leonardo Bronfman, email: leo(at)

Performing observations with APEX

Observations at APEX are normally done in service mode. For questions, please contact the APEX station manager, Lars-Ake Nyman, email: lnyman(at)

Once you proposal is accepted, you need to prepare the observations. This basically means you need to inform the APEX staff about everything which is important for carrying out your observations, including source coordinates, receiver setup, possible pointing sources, observing procedures, etc.

The documents in this section are currently prepared and will be made available through this web site in March 2006.

  • APEX Observing DataBase

    Once we have received all setup information for your accepted project, a project account will be created in the APEX Observing data base. This account will allow you to monitor the progress on your observations, or to update observing instructions for your project.

Reducing APEX data

The APEX raw data are in the so-called MB-FITS data format. For line observations, these raw data are calibrated on-line by the OnlineCalibrator program, which writes the calibrated spectra into a CLASS-format data file. The data can be further reduced and analyzed using for example CLASS and GRAPHIC or MAPPING program of the GILDAS software package.

Related Links:

Multi-Beam FITS Raw Data Format - Interface Description (pdf)


Send comments to APEX Web Team

Last update : March 1, 2006