ʻŌnohiʻula Prime Focus Spectrograph (PFS)

Information

Call for Proposals for S27A

   The principal investigator (PI) must read Observations page and follow the instructions for observation planning and proposal preparations.

  Telescope downtime The telescope will be unavailable for maintenance during two periods: (1) from February 1 to mid-March for AZ/EL incremental encoder replacement, and (2) beginning in mid-July for primary mirror recoating. Please make observation plans with careful checking of target visibility.

We are calling for community fillers for S27A
   Please read the page for Fillers carefully when planning to submit a community filler proposal.

Updates for CfP S27A
   Policy for ToO and transient observations was added. Please review carefully when planning to submit a ToO proposal.
   Citation and Acknowledgements was added. Please refer to this page for publications involving PFS data.

Information for S26B observers

   Important notice for S26B: SM2 NIR (N2) Detector Replacement in S26A is completed. The N2 detector is back to normal operation.
   PFS DRP Tutorial: Visit for details on PFS Data Reduction Pipeline.

Introduction

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The PFS instrument has the Hawaiian name, ʻŌnohiʻula

See also the announcement in Subaru topics and PFS Blog.
The pronunciation of ʻŌnohiʻula is "oh-no-he-oo-lah" in the phonetic spelling for English speakers, and "オーノヒウラ" in the phonetic spelling with Japanese Katakana. Click to hear 'Ōnohi'ula
See also ʻŌnohiʻula PFS Usage and Citation Guide (Jan-10-2026).

The ʻŌnohiʻula Prime Focus Spectrograph (PFS) is a spectrograph system mounted at the prime focus of the Subaru telescope. Four identical spectrograph modules are fed by a total of ~2400 fibres, allowing for simultaneous observations of ~2400 targets within a very wide-field (~1.25 deg²). The spectra cover a wide wavelength range from 0.38 μm to 1.26 μm, with a resolving power of approximately 2,300 in the blue channel, and up to 5,000 in the red channel (medium resolution mode).

In principle, observations will be conducted in queue mode, to maximize the observing efficiency by optimizing the fiber positions. Classical mode observations can be requested for observations that require exposure times other than 15 min, specific configuration of pointing centers, or time-critical execution.

Please review the Observations page carefully when planning to observe with PFS. For proposal preparation, please also refer to Getting Started Manual.

Instrument

• Overview
• Basic instrument parameters
• System efficiency
• FITS header
• Publications

Observations

• Observation modes

  • Queue mode
  • Classical mode
  • Target of Opportunity (ToO)
    • Policy for ToO and transient observations
  • Fillers

• Proposal and Observation preparations

  • Tutorial materials
  • Applicable to all modes
    • Requirements on uploading multiple target list
  • Template of Technical Justification

• Queue mode preparations

• Classical mode preparations
  • ToO preparations
• Community filler preparations

• Additional information

• Relevant documents

• Tools

  • PFS Spectral Simulator
  • PFS Target Uploader

Data access and reduction

• Queue progress
• Data access
• Data reduction pipeline
• PFS science platform
• PFS DRP Tutorial

Current status

• Status of instrument
• Status of DRP development
• Performance verification

Links

• PFS Project
• Proposal of PFS Subaru Strategic Program (SSP)
• Getting Started Manual for preparation of PFS proposal.
• Tutorial of PFS Target Uploader
• Tutorial of PFS Spectral Simulator (ETC)

Citation and Acknowledgements

Contact

PFS observation helpdesk

Questions regarding proposal and observation preparation:

PFS data reduction and analysis helpdesk

Questions for data reduction processes:

Some of our helpdesk members are non-Japanese speakers. In principle, please ask your questions in English. Responses to questions in Japanese may take some extra time.