Gemini Overview of the telescopes Gemini’s core science goals Gemini instrumentation Applying for Gemini time 2001 Observational Techniques Workshop Warrick Couch, UNSW

AUSTRALIA AND ESO  Ron Ekers met with Catherine Cesarsky (DG of ESO) on 13 March: entrance fee would be EU23M (A$41M) & annual subscription of EU4M (A$7.1M) [VLT, ALMA, but no other ESO telescopes]  For ~5% of Gemini, Aus paid US$9.6M (A$19.2M) entrance fee and pays US$1.2M (A$2.4M) annual subscription.  Chile’s 5% share of Gemini likely to be on offer to Australia for the same price.  Notice of intent of MNRF bid for generic 8m time submitted by NCA yesterday.

Gemini North Gemini South Overview of the telescopes (total capital cost = US$187M)

Gem-NGem-S Primary mirror: 8.1m diameter 20cm thick mass = 22.2 tonnes coated for UV/IR performance

Primary mirror supported by air pressure actuators which maintain shape to better than a micron. Secondary mirror (f/16): 1.0m diameter Mass 45kg Fast tip-tilt at up to 200Hz

Cassegrain Focus: Instrument Support Structure + A&G

Core Science Goals Circumstellar disks and planetary systems Formation of the elements Formation and evolution of galaxies Star formation Stellar interiors structure

Circumstellar disks and possible planetary systems The nature of the particle disks discovered around stars like  - Pic  detailed mapping to understand the process of planet formation. Map at 10  m and beyond, where Gemini should deliver a resolution of better than 0.3 arcsec, corresponding to 1-2AU for the nearest examples. Gemini’s competitive edge: diffraction-limited imaging and low thermal emissivity.

Formation of the elements Determination of the chemical enrichment history of the Galaxy and the Universe via high resolution spectroscopy of the oldest stars in the Milky Way and gas clouds illuminated by distant quasars. High-resolution (R=50-150,000) spectroscopy of faint objects at uv-optical wavelengths  This science program severely compromised with the cancellation of HROS, and its replacement with HRBS which, being fibre-fed, will be unable to observe at  3800Å.

Formation and evolution of galaxies Determine the morphology, content, and composition of nascent and adolescent galaxies in the early universe. Do this at optical wavelengths, to reveal the properties of the youngest stars in such systems, through to the thermal infrared where dust re-radiates the emission at shorter wavelengths. Imaging and multi-object spectroscopy at optical and infrared wavelengths, with high spatial resolution.

Star formation Address the age-old question of how stars form and what conditions lead to proto- stellar collapse. In particular, study the role of outflows in the star formation process Near infrared imaging and spectroscopy at the highest possible spatial resolution Gemini advantage: diffraction-limited performance (or near to) in the near-infrared.

Stellar structure Determination of the internal structure of stars through the study of the small and complex oscillations that take place at their visible surface. Very high resolution optical spectroscopy and continual monitoring for many hours.

Performance: it’s not just (aperture) size that counts! * For 8m,  dl ~0.02” in V, 0.07” in K, requiring wavefront correction using Adaptive Optics (only practical in IR) If sky- or detector-noise limited, then speed of observation (1/t) is proportional to: (D/  ) 2 where D = aperture size and  = image size.  is usually dominated by seeing, with  seeing  -0.2  20% reduction V  K. If can achieve diffraction-limited performance*, then  dl  1 /D (Rayleigh) and speed proportional to: D 4 [factor of 16 in going from 4m to 8m telescope!!]

Seeing Constraints

2001B Instrument Availability  NIRI  GMOS  Hokupa’a/QUIRC  FLAMINGOS-1  OSCIR  Acquisition Camera Mauna KeaCerro Pachon

2002A Instrument Availability  NIRI  GMOS  MICHELLE  Hokupa’a  CIRPASS  T-ReCS  PHOENIX Mauna KeaCerro Pachon

2002B Instrument Availability  NIRI  GMOS  MICHELLE  ALTAIR (NGS)  CIRPASS  T-ReCS  GMOS  FLAMINGOS-1  PHOENIX Mauna KeaCerro Pachon

2004B Instrument Availability  NIRI (NIR)  GMOS (Opt)  NIFS (NIR)  OSCIR (MIR)  ALTAIR+(LGS/AO)  T-ReCS (MIR)  GMOS (Opt)  GNIRS (NIR)  NICI (NIR)  HRBS (Opt)  FLAMINGOS-2 (NIR)  MCAO (LGS/AO) Mauna KeaCerro Pachon

2001B Instrument Availability  NIRI (C & Q)  GMOS (Q)  Hokupa’a/QUIRC (C)  FLAMINGOS1(C)  OSCIR (C)  Acquisition Camera (Q) Mauna KeaCerro Pachon NIGHTS ATAC HAS TO ALLOCATE 4 2 C=classical (min = 0.5N), Q=queue (min = 1hr)

Hokupa’a/QUIRC  Hokupa’a  36 element curvature wavefront sensor and bimorph mirror which uses natural guide stars.  QUIRC  1 – 2.5  m near-IR camera which is fed by Hokupa’a. 1024x1024 HgCdTe array; pixel size = 20 mas  20.2 arcsec FoV!  Performance: near diffraction-limited (d-l) resolution in H & K; FWHM = 2x d-l in J.  The rub: must have a bright point-source within 30arcsec of target!

Hokupa’a Demonstration Science Results  Overview of data:  Used 12 nights at 4hrs/night  0.7” seeing at zenith delivered FWHM (H,K’) = 0.08” ”!  10 fields of 20”x20” mapped in H and K’  From 6 min (K’) / 12 min (H) to 40 min per field  CO and K-cont on most fields  Data released to community. ~50 CDs distributed. Reduced data and PR material.

UH-88”, Courtesy W.Brandner, 0.65” seeing Filters: H K’ CO CO cont. 4’ IRS7 SgrA* >10 stars per arcsec 2 at K~18 Bow shock Very high extinction clouds 40” 5” >220 stars in 5”x5” IRS8 (bow shock)

Public SV Data: M32  Used core of this nearby elliptical galaxy as WFS reference  K’  480s  0.13” FWHM 0.5 arcsec

Public SV Data: M15  Measured PSF variation over field and H/Q stability and repeatibility on this globular cluster  2 datasets released  K’  18 x 30s  0.12” FWHM 20 arcsec

Example QS Data Elliptical galaxy at 150Mpc FWHM 65 milli-arcsec IR surface brightness fluctuations (GN-2000QS-Q-9)

Example QS Data: Galaxies in Abell 665 Colour composite of Abell 665 (z=0.18)  K’ (28min)  J (20 min)  HST-I (80 min)  0.2 arcsec FWHM (GN-2000QS-Q-29)

NIRI – Near Infrared Imager  Detector: 1024x1024 Aladdin InSb array  Imaging:  ‘wide-field’ (2’x2’) f/6 mode ( J – L bands)  ‘low-bg’ (0.9’x0.9’) f/14 mode ( J, H, K )  ‘high-bg’ (0.9’x0.9’) f/14 mode ( L & M )  Spectroscopy:  Long-slit + grism ( 1 – 5.5 microns) [ R of up to ~1700 (in H) with 0.23” slit ]  Wavefront correction:  Active optics (aO) only, with IR on-instrument wavefront sensor available except in f/6 mode  f/32 camera will be fed by ALTAIR (laser g/s)

NIRI Filters available for 2001B  J  H  K, Kshort, K´  L´  M´  Order sorting filters:  J, H, K, L, M  [Fe II]  H-continuum  H S(1)  Br Gamma  K-continuum (2)  PK50 long-wave blocker  Integration Time Calculator (ITC) available 

GMOS – Gemini Multi-Object Spectrograph  Optical spectrograph/imager with a 5.5’ field of view [duplicated for both telescopes]  Spectroscopic modes:  standard ‘long-slit’  ‘multi-object’ using aperture mask with multiple slits [ up to several hundred in 5.5’ FoV]  Integral Field Unit (IFU) covering 50 arcsec 2 with 0.2” sampling  Spectral resolution: R = 670 – 4400 (0.5” slit)  ITC available

FLAMINGOS-1  World’s first fully cryogenic multi-object near-IR ( J, H, K ) spectrograph/imager.  Field of view = 2.7 arcmin (f/ x2048 Rockwell HgCdTe array).  ‘Long-slit’ and ‘multi-slit’ modes  Spectral resolution: R = 300 (low!) [grisms giving R~2400 planned].

OSCIR  Mid-infrared (8-25  m) imager and low/medium resolution (R= ) spectrograph.  Uses a 128x128 SiAs detector.  Field of view = 11 arcsec!  Range of broad/narrow filters available centred on: 7.9, 8.8, 9.8, 10.3, 11.7, 12.5, 18, 20.8  m + N-band (10.8  m)  Uses chopping secondary capability of Gemini telescopes.

Acquisition Camera  Optical CCD camera, which can provide U,B,V,R,I imaging over a 2’x2’ field.  Offered in 2001B to develop `quick response’ mode of operation (e.g. for SN and gamma-ray burst follow-up).  ITC available

MCAO Imager Design Guidelines  Sensitive from µm  Single plate scale that critically samples the AO corrected PSF at H (~0.02 arcsec/pixel)  Samples the full ~80 arcsec diameter AO corrected field of view  ~4096x4096 focal plane detector  Optically compatible with nominal f/30 output beam of AO system  Built in fast guiding (tip/tilt) capability  Assortment of narrow and broad band filters  Full facility class system, compatible with Gemini standard interfaces, control environment, handling equipment, etc.  Uses NIRI vacuum jacket, basic cold structure, space frame to package instrument

Applying for time on Gemini – it’s the PITs! Proposals to use Australia’s share of time on Gemini are considered by ATAC; semester deadlines are:  March 31 st (for ‘B’ semester, Aug-Jan)  Sep 30 th (for ‘A’ semester, Feb-July) If you collaborate with people from other partner countries, then time can be sought from their TACs as well.

Applying for time on Gemini – it’s the PITs! Gemini proposals are assembled and submitted using the Phase-I Tool (PIT), a supposedly user-friendly ‘GUI’-styled program* which solicits:  all the usual info: title, abstract, instrument/mode required, nights (D,G,B), list of targets, guide stars, etc  PLUS attached 3-page postscript file containing scientific justification (and figures) for ATAC Once complete, hit the “SUBMIT” button in PIT; it then verifies your proposal and (if OK) sends it to the AAO for official submission. *that should be generally available at your institute; ask your system manager!

Applying for time on Gemini – extra requirements Guide stars:  these need to be selected and listed along with each target object: at a minimum, 1 is required for the peripheral wave front sensor (PWFS), with additional guide stars required if instrument has an On-Instrument Wave Front Sensor (OIWFS), and/or observations involve AO.  The PIT makes the selection process simple through internet links to a guide-star catalog (USNO) and digital sky survey.

Applying for time on Gemini – extra requirements “Classical” or “Queue” time (where there’s a choice)?  Classical time is the traditional type of allocation where your nights are scheduled and you travel to the telescope (minimum allocation = 0.5 nights).  Queue scheduled time is where your observations are executed by Gemini Observatory staff at a time when the conditions best suit your program. In this case you have to be much more specific about the observing conditions: seeing, cloud cover, water vapour content, sky and telescope background, air mass. (minimum allocation = 1 hour).

Key web addresses  (Australian mirror of the main Gemini web site – with all the information on the telescopes/instruments)  (Australian Gemini Office web site – with all the information relevant to Australian users)  ons/ATAC-applications.html (information on applying for time through ATAC) ons/ATAC-applications.html