Telescope System Summary

Status pages

Monitors (internal)

Frontends

Heterodyne Receivers

• EmirforAstronomers : EMIR (Eight MIxer Receiver)
• HeraforAstronomers : HERA 3×3 dual-polarisation 1mm receiver
• AbcdforAstronomers : old ABCD receivers (decommissioned in 2009)

Continuum Cameras

• The new wide field-of-view camera NIKA-2 has been installed in October 2015. After a successful science and verification run in April 2017, NIKA2 has been available for regular observations since October 2017. Commissioning of 1mm polarimetry is ongoing.
• NIKA-1 was a small camera working at 2 and 1mm, which had been offered for regular observations between 2013 and the winter semester 2014/15.
• The GISMO 2mm camera was available for regular observations between 2011 and the winter semester 2014/15.
• The MAMBO2 1mm camera was decommissioned in spring 2011. The 117pixel large field 1.2mm bolometer camera MAMBO2 was installed at the 30m since 2001/2002.

Telescope efficiencies and beam widths

Iram30mEfficiencies

Backends

Backends for EMIR and HERA
Backends for the old ABCD receivers (till mid March 2009): BackendsForAbcdReceivers

Control System

The 30-m telescope runs under the New Control System (NCS), see: NCS documentation

Observing Modes and Switching Modes

• for more details on observing and switching modes, see the section “NCS explained” in the pako cookbook
• swTotal stands for total power observations without switching, while still using the internal synchronization signals.
• swBeam beam switched observations using the chopper wheel on mirror M4.
• swWobbler switching the wobbling secondary (M2). The maximum allowed throw is +/-2′.
• swFrequency switching the local oscillator frequency
• Pointing: Using nearby (within 10 degree) pointing sources, <1″ accuracy can be obtained; with absolute (“blind”) pointing, the accuracy is about 2″ rms, the receivers are aligned within 1.7″ (see the Telescope Status page for current values). Checking the pointing and alignment (using e.g. a planet) is the responsibility of the observer.
• Focus: residual errors of <1mm may need correction. There are systematic differences of upto 0.6mm in the focus of the different receivers (cf. Telescope Status page). The focus is subject to change especially during sunrise and sunset.
• Position switching (psw): the combination of ONOFF with swTotal is called “Position Switching”. Only relative off-source reference positions are possible.
• Wobbler switching (wsw): often called double beam switching mode: max. 240″ throw at 0.25 Hz, standard phase duration 0.5 Hz.
• Frequency switching (fsw): max. 45 km/s throw up to about 10 Hz.
• On the fly mapping (Heterodyne): Works with all receivers and backends, typical dump rate 0.5 to 10 Hz. OTF can be observed without reference position, e.g. for galaxies, and MIRA is able to use emission-free OTF data as reference!
• Raster mapping is at present not offered. The observer may want to use either psw or otf instead.
• Polarimetry with EMIR connected to VESPA

Weather station and Taumeter

• Weather station
  Wind velocity and direction measured on hill behind the telescope
  Outside temperature and relative humidity measured at base of telescope. In case the sensors are frozen, the operator will use a mobile weather station and enter values by hand into the drive program.
  Pressure measured at entrance to control building
• Taumeter does regular skydips to inform the observer about the sky transmission near 225GHz. The local oscillator works at 225GHz. The IF is 1.5GHz and the bandwidth is 0.5GHz. It is a double-sideband Schottky receiver.

Old Telescope System Summary page of September 07