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Gemini Explores Fading Active Galactic Nuclei ID'd by Galaxy Zoo

Figure 1: Minimum ionizing luminosity of extended AGN-ionized clouds along the projected radius. These Hubble Space Telescope data show a luminosity drop in the last 20,000 years before our direct view of the nucleus, characteristic for all AGN of this study.

Gemini North welcomes Band 4 proposals using GNIRS or NIRI in poor weather conditions

Gemini-North is in need of poor weather programs that can take CC80 or worse and/or IQ Any using NIRI or GNIRS ONLY. If you have an idea for a program that can take such conditions, please see the Poor Weather Proposal Process web page for more information on applying for Band 4 time.

Exposure times

The following five tables provide various exposure time limits. Constraints are due to a number of factors, more than one of which may need to be considered for a given NIRI configuration:


Table 1: Minimum Recommended Exposure Times (sec)

Staff List

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NIRI

NIRI (Near InfraRed Imager and spectrograph) - Gemini North

Capability: 1-5 micron wavelength seeing-limited, Natural Guide Star (NGS) Adaptive Optics (AO), or Laser Guide Star (LGS) AO imaging

NIRI is only available for queue, priority visitor, and classical imaging observations due to problems with the focal plane mask and beam splitter mechanisms. The NIRI spectroscopy pages are provided for archival data reduction.  

NIRI Optomechanical Layout

NIRI is an near-IR imager/spectrometer operating over the 1 to 5um wavelength regime. The instrument is cryogenic and is cooled by two Leybold closed-cycle cooler units to an IR array operating temperature of around 30-35K. All optical elements inside the NIRI cryostat are cooled and, in general, will reach operating temperatures of around 60 to 80K. Since NIRI is cryogenic, the cryostat is pumped and cryo-cooled to a pressure better than 10^-5 torr.

Gemini North Telescope Visit Request Form

Gemini North January NIFS and laser access cancelled

The repair of the Gemini North laser system is proceeding but insufficient progress has been made to offer the laser this month. Because all but one NIFS program requires the laser, this also means we will not be doing the NIFS/NIRI swap this month, as previously planned. NIRI will remain on the telescope and NIFS will not be available. We remain optimistic that we will be on-line for the planned February NIFS+LGS run. Updates will be posted.

Guiding Options

Natural Seeing (Non-Adaptive Optics) Guided Observations:

NIRI standalone (i.e., without AO) requires the use of a peripheral wavefront sensor for both imaging and spectroscopy. PWFS2 is preferred over PWFS1, as it can be used on fainter guide stars, can run at a higher frequency for a given guide star, works better under windy and cloudy conditions, and is smaller and thus vignettes less of the field of view.

f/6 imaging: PWFS2 guide star should be located >5' from the target

Delay to Gemini North NIFS Laser Run

The Gemini North laser system has developed a hardware fault. We are working on a repair which is proceeding quite well but the final prognosis is still not known. January's NIFS+LGS run is delayed and shortened, and may even have to be cancelled. We are optimistic that we will be on-line for the planned February NIFS+LGS run. Updates will be posted.