Science drivers

The Giant Magellan Telescope (GMT) will be a revolutionary scientific facility. Its great light-gathering power will allow the high-redshift Universe to be probed in exquisite detail. Its large aperture will permit diffraction-limited adaptive-optics observations at unprecedented angular resolution - 3.8 times better than the James Webb Space Telescope (JWST) at the same wavelength.

GMTIFS will exploit both of these GMT advantages. Its combination of an adaptive-optics-corrected Integral-Field Spectrograph (IFS) with an adaptive-optics Imager matched to the corrected field of the GMT Laser Tomography Adaptive Optics (LTAO) system will make GMTIFS the workhorse adaptive-optics instrument for the GMT community.

GMTIFS will address many of the key science drivers for the GMT telescope spanning the full range of cosmic history:

  • Observations of the near-infrared counterparts of Gamma-Ray Bursts will probe the structure of the intergalactic medium at the epoch of reionisation beyond z ~ 7 using the high spectral resolution of the GMTIFS IFS. Deep near-infrared observations of redshifted Lyα will probe the first galaxies at z > 7.

  • The mass assembly of galaxies over cosmic time will be studied using kinematic measurements of Lyα and Hα emission that exploit the high sensitivity of the GMTIFS IFS. The broad wavelength coverage of the IFS will be used to study the associated chemical evolution of these galaxies via spatially-resolved measurements of their rest-frame-optical emission-line ratios. The high angular resolution of the GMTIFS Imager will be used to probe the build-up of the stellar components of these galaxies via broad-band near-infrared imaging. In these ways, GMTIFS will provide essential follow-up observations for the large samples of high-redshift galaxies that will be identified at lower angular and spectral resolution with JWST.

  • Feedback processes occurring during the formation and early evolution of massive galaxies will be investigated through kinematics, excitation, and abundance gradient studies with the GMTIFS IFS. These will reveal how gas processes affected the evolution of the baryonic component of galaxies residing within dark-matter halos. The end products of this feedback - early "red and dead" massive galaxies will also be studied through measurements of their dynamical masses from stellar velocity dispersion measurements.

  • The GMTIFS IFS will probe the most massive nuclear black holes in the Universe via high-angular-resolution measurements of stellar kinematics in some objects and Keplerian motions of circumnuclear gas in other objects. These observations will clarify the intimate relationship between nuclear black-hole mass and host galaxy stellar properties at the highest black-hole masses, and elucidate the upper black-hole mass limit and its evolution over time.

  • The GMTIFS IFS will also probe the least massive nuclear black holes in nearby galaxies and investigate the duality of low-mass black holes and nuclear star clusters as alternative end-products of bulge formation in lower mass galaxies.

  • The high angular resolution and high spectral resolution of the GMTIFS IFS will combine to probe the jet outflows and planet-forming circumstellar disks associated with nearby forming stars in unprecedented detail. This will reveal the internal structure of the outflows and constrain the launch physics of their jets. IFS measurements of near-infrared emission lines originating at the disk surface will complement mm-wave probes of the disk interior exploited with ALMA.

  • The high angular resolution of the GMTIFS IFS will allow spectroscopic studies of outer exosolar planets identified in near-term Extreme Adaptive Optics surveys on 8-m telescopes.

Updated:  22 September 2017/Responsible Officer:  RSAA Director/Page Contact:  Webmaster