Subject: breve relatorio sobre a reuniao de Aspen Date: Thu, 3 Jul 2003 10:32:47 -0200 From: "Laerte Sodre Jr" To: geminiaspen@lna.br Prezados colegas, A reuniao em Aspen foi extremamente intensa e interessante, tendo sido discutidos inumeros topicos cientificos, bem como tecnicas e estrategias observacionais. Os casos cientificos serao redigidos nos proximos meses e posteriormente divulgados junto 'a comunidade Gemini. Para executar estes projetos, 47 instrumentos foram propostos (0.5 por participante!), com diferentes resolucoes e comprimentos de onda, e objeto unico/multi-objeto. Apos a reuniao, os coordenadores dos grupos e dirigentes do Gemini se reuniram e produziram uma lista provisoria de instrumentos prioritarios, que encontra-se no anexo 1. Esta lista sera agora negociada com os parceiros e as agencias nacionais de financiamento. O anexo 2 contem um resumo da motivacao cientifica produzida pelo grupo de altos redshifts. A mensagem basica deste grupo e´ que sem grande campo nao e´ possivel se ter um Gemini competitivo em astronomia extragalactica e cosmologia. A home page deste grupo - nero.astro.utoronto.ca/~abraham/phpwiki/index.php/GeminiAspen - contem material e discussoes que podem ser de interesse tanto para os colegas teoricos quanto observacionais. O diretor do Gemini Matt Mountain participara´ da proxima reuniao anual da SAB. Havera congresso sobre polarimetria em meados de marco/2004, em Kona. Contactar Colin Aspin = caa@gemini.edu. Abracos a todos, Beatriz e Laerte --------------------------------------------------------------------- Name: Executive_Session_file.xls Executive_Session_file.xls Type: Microsoft Excel Worksheet (application/vnd.ms-excel) Encoding: base64 --------------------------------------------------------------------- Galaxy Formation and the High-Redshift Universe - The Universe of Energy - First Light - Science goals - Probe the physics of re-ionization (the imprint of which is recorded in the evolving space density of first light sources). - Constrain the contribution to re-ionizing flux contributed by AGN. - Predict the nature of population III systems. - Specific measurements - space density of z>8 galaxies as a function of Ly α flux - possibly: chemical abundances and IMF of first stars (actually, second stars) by probing the rich region in wavelength range 1300Ă…-2000Ă…, either by targeting a highly lensed subset or by co-adding enough sources. - Required capability: narrow FOV AO-fed ultra-high multiplexing IR spectroscopy – PRIORITY - Wavelength Range: NIR - Rationale: Lyman-alpha in IR above z=8 - Spatial Resolution: 0.2" - Rationale: small sizes of sources - Spectral Resolution: > 3000 - Rationale: get between OH - Field of View: 5' - Rationale: high space density of sources (0.5 arcmin-2 to z(AB)=26.5) - Multiplex Gain: panoramic or close to it. - Reference Instruments: - Near-IR tunable filter - Image slicer feeding a near-IR MOS - Studies/supporting observations needed: - Efficacy of GLAO - Confirmation of high source density of z-band dropouts - Synergy with other facilities: - JWST - ALMA - WMAP - Planck - How to sell it to my grandmother - Discovery of these systems would be the apex of 50 years of effort to discover the ultimate origins of galaxies, and by extension also origin of the chemical elements heavier than helium. The emergence of these systems can be viewed as the defining moment (“let there be light”) where stars emerge from the primordial stuff of the big bang. - Dark Energy - Science goals - needs attention - determine the dark energy equation of state w to precision 2% using probes of angular diameter distance - make a first pass at measuring the rate of change of w. - Specific measurements - power spectrum of galaxies in two redshift channels (z~0.8, z~2) - distance between first (how many?) acoustic peaks to 2% accuracy. - Required capability: wide FOV optical spectroscopy of multiple Sloan volumes at z~1 and z~2.5 – PRIORITY - Wavelength Range: optical - needs attention - Rationale: At low redshift the linear regime barely extends beyond first acoustic peak so one cannot use inter-peak distances as a cosmic measuring rod. At high redshift everything converges to Einstein-de Sitter. Consequently the “sweet spot” for undertaking this measurement is around z=0.8. At higher redshifts Lyman break galaxies will also give a measurement at z=2 which is also useful. - Spatial Resolution: 0.5"-1.0" - Rationale: ? - Spectral Resolution: >500 - Rationale: minimum required for precision redshifts - Field of View: >30' - Rationale: Massive volume needed. - Multiplex Gain:>1000 - Reference instruments: - 1Âş – 2Âş FOV fibre-fed MOS - >30' FOV multislit MOS - Trade studies/supporting observations needed: - Careful look at whether it wouldn't be better to do this with a 4m telescope (chuck says forget it) in the near-IR or by adding a spectrograph to an alternative telescope. - Huge-area deep UBVI imaging to find sample of LBGs for z=2 component. - Synergy with other facilities: - SNAP - LSST - WMAP - Planck - Required capability: wide FOV optical spectroscopy of multiple SNe Ia candidates - Wavelength Range: optical - Spatial Resolution: 1" - Spectral Resolution: - Rationale: need to do reliable Ia typing - Field of View: 1.5Âş - Rationale: needed to do 10 candidates simultaneously - Multiplex Gain:10 - Reference Instrument: fibre-fed MOS spectrograph - Studies/supporting observations needed: none - Synergy with other facilities: - SNAP - CFHT Legacy Survey - WMAP - Planck - How to sell it to my grandmother - Dark energy is apparently responsible for 70% of the energetics of the Universe, is completely mysterious, and represents a direct connection between galaxies and high-energy physics. It is sufficiently important that it's worth studying in as many different ways as possible. - The Universe of Mass - Galaxy formation - Science goals - directly determine non-baryonic mass and halo dynamical state of high-redshift galaxies. - connect properties of halos with morphological properties of galaxies. - explore the connection between chemical enrichment history, star-formation history, disk angular momentum/size, and nuclear activity to the dynamical masses of both halos and central black holes as a function of redshift. - make more specific - connect the global energetics of galaxies to their redshift distributions and star-formation histories - Specific measurements - vrot/vrand, peak of rotation curve, disk kinematical temperature and size at a range of redshifts spanning the peak epoch of galaxy assembly. - Dynamical state as a function of morphology, luminosity-weighted age, recent star-formation history, chemical abundance, and environment. - Redshift distributions of systems as a function of peak wavelength of energetic emission and nuclear activity (e.g. samples from SCUBA2, XMM, etc). - black hole mass as a function of redshift - Required capability: Narrow FOV diffraction-limited near-IR spectroscopic mapping (e.g. NIFS fed by Altair so not discussed here). - Required capability: Intermediate-FOV near-IR spectroscopic mapping – PRIORITY - Reference instrument: GLAO-fed deployable IFU - Wavelength Range: NIR - Rationale: need for [OII] in wavelength range. - Spatial Resolution: 0.2" - Rationale: Want around 10 resolution elements spanning typical L* disk systems at z=1. - Spectral Resolution: > 3000 - Rationale: Need to get between OH - Field of View: 10' - Rationale: target density of luminous disks at z=1 - Multiplex Gain: 10 resolved targets (e.g. 10 IFUs) - Trade studies/supporting observations needed: - Efficacy of GLAO - Experience with AO-fed IFU systems to determine best approach to deal with photon starvation (multiplexing with coarse resolution vs. diffraction limited observations of single systems) - Comparison with N-body simulations to determine relative information gain of IFUs vs. stepped narrow slits. - Synergy with other facilities: - JWST - ALMA - Required capability: Intermediate-FOV near-IR spectroscopy - Reference instrument: GLAO-fed IR MOS - Wavelength Range: NIR - Rationale: need for [OII] in wavelength range. - Spatial Resolution: 0.2" - Rationale: take advantage of GLAO image quality - Spectral Resolution: > 3000 - Rationale: Need to get between OH - Field of View: 15' - Multiplex Gain: 100 objects - Trade studies/supporting observations needed: - Efficacy of GLAO - Comparison with N-body simulations to determine relative information gain of IFUs vs. stepped narrow slits. - Synergy with other facilities: - HST - JWST - Ground-based IR surveys - Required capability: High-efficiency intermediate-FOV UV-optimized spectroscopy – PRIORITY - Reference instrument: Two-channel UV-optimized + optical-optimized spectrograph - Does the IR channel really make sense? Would a 30' FOV in a UV-optimized spectrograph alone be exciting enough? I'll assume a two-channel instrument for now… - Wavelength Range: NUV–1 micron - Rationale: NUV highly efficient for redshifts in critical range 11.5 for abundances). - Spatial Resolution: 0.7" - Rationale: small sizes of sources - Spectral Resolution: > 500 in optical - Rationale: >500 in optical to get precision redshifts, >2000 in near-IR to get between OH - Field of View: >20' - Rationale: high space density of sources (0.5 arcmin-2 to z(AB)=26.5) - Multiplex Gain: ~1000 - Trade studies/supporting observations needed: - Efficacy of GLAO - Relative exposure times in optical vs. IR assuming N&S observations of faint sources - Synergy with other facilities: - SCUBA2 - XMM - How to sell it to my grandmother - Galaxies are to the Universe as atoms are to chemistry – the fundamental building blocks of the Universe. Their properties (mass, chemical composition, formation history) directly condition the formation of life. We still do not know how galaxies form but progress over the last 10 years has at least let us determine when they are formed (mostly at 17 in the form of gamma-ray bursts. - Determine bias between the distribution of faint quasars and the underlying field population. - Explore the connection between galaxies and the IGM at high redshifts. - Specific measurements - cross-correlation function between high-z QSO population and field galaxies. - lyman alpha forest tomography on scales of ~10 Mpc via QSO/bright galaxy sitelines - Required capability: UV-optimized wide FOV spectroscopy - Reference instrument: UV-optimized multislit spectrograph - Wavelength Range: NUV-Optical - Spatial Resolution: 0.7" - Spectral Resolution: 3000-5000 - Field of View: 30' - Multiplex Gain: 20 - Rationale: To I<24 the space density of QSO's is : 200/deg2 with z<2.5, 806. Want samples of thousands in a sensible redshift range. - Required capability: Rapid reaction T.O.O. override capability added to queue system. Automated communication with auxiliary robotic telescope. Quasi-instantaneous instrument switching. - Reference Instrument: Existing instrument load adequate - Wavelength Range: Optical/IR - Spatial Resolution: varia - Spectral Resolution: varia - Field of View: 5' - Time to target: 30 min - Rationale: targets are fading incredibly fast but for most interesting targets (z>5 say) time dilation buys you some extra time. - Multiplex Gain: 1 (longslit) - Some Definitions: - narrow FOV: < 6' diameter - intermediate FOV: ~15' diameter - wide FOV: > 30' diameter - ultra-high multiplexing: area density of order 20 light-collecting apertures per squre arcmin OR panoramic mapping