Dr. Andrew Benson (Caltech)
I will describe recent developments in the modelling of galaxy formation physics with an emphasis on high redshifts using a combination of N-body simulation and state-of-the-art semi-analytic techniques. I will focus on issues of robustness and reliability in the predictions and will address the question of which aspects of the theory we will be able to test and rule out with JWST observations. Additionally, I will highlight areas where further theoretical understanding will be crucial to fully maximizing the impact of the JWST for galaxy formation science.
William Borucki (NASA Ames Research Center)
The Kepler Mission's nearly continuous multi-year observations of over 150,000 stars and their planetary systems will provide JWST with numerous interesting targets. A number of planets discovered by Kepler with relatively bright host stars will be amenable to JWST NIRSpec and MIRI transit and eclipse spectroscopy observations to probe their atmospheric compositions and temperature profiles. Combining Kepler and JWST light curves will also produce new science by confirming transits of interesting Kepler candidates (no color change in light curves), measuring their impact parameters, and measuring their day / night heat transfer with light curves spanning the visible to the IR. JWST will also be able to exploit Kepler observations of many interesting stars, including studying nearly colliding A stars, white dwarfs transiting and being occulted by hot main sequence stars, studying oscillations and variability over a large wavelength range, and characterizing stellar surface structure and features during planetary transits. Examples of these phenomena and others will be described and presented.
Prof. Daniela Calzetti (University of Massachusetts)
I will review the current status of our understanding of the relation between star formation and the gas supply on galaxy scales, and discuss future developments that will be enabled by the JWST, both locally and at higher redshifts.
Dr. Karina Caputi (University of Edinburgh)
I will discuss the unique role that JWST/MIRI will have for constraining galaxy stellar mass assembly at high redshifts, and thus testing current models of galaxy formation. I will show how MIRI deep galaxy surveys will be able to probe more than one order of magnitude deeper in stellar mass than the latest deep Spitzer/IRAC surveys, which is fundamental to find the building blocks of the first massive galaxies.
Dr. Mark Clampin (GSFC)
The James Webb Space Telescope (JWST) is a cryogenic, 6.5 meter diameter space telescope. JWST has a unique architecture, compared to previous space telescopes, that is driven by its science requirements, ia passively cooled cryogenic design, and the need to stow the observatory for launch. JWST's large, segmented mirror imeets the requirement for high angular resolution in the infrared coupled with a significant increase in collecting area compared to the Spitzer and Hubble Space telescopes in order to detect the first galaxies. JWST's unique five-layer sunshield allows the telescope and instrument module to passively cool to cryogenic temperatures. JWST will be launched on an Ariane 5, and so both its telescope optics, and the sunshield have to be stowed in order to fit the Ariane 5 fairing. Following launch the sunshield and telescope optics must be deployed, and the primary mirror phased for science operations. In this presentation we will review the design of the observatory and highlight recent progress in the construction of the JWST observatory. In particular, we address recent progress with the telescope optics, sunshield and spacecraft. We will discuss predicted observatory performance in terms of the scientific goals of JWST and address key operational considerations that might bear upon frontier science observations.
Prof. Richard Ellis (Caltech)
JWST offers the exciting prospect of revealing the physical nature of star formation in the first galaxies, their role in enriching and ionizing the intergalactic medium, and how feedback processes in early systems govern the subsequent assembly history of galaxies. A cosmic frontier barely visible with the deepest current ground and space-based observations will be systematically explored and extended; we can expected both rapid progress and many surprises! The talk will highlight the possibilities and emphasize the need for continued synergy with the next generation of ground-based telescopes.
Dr. Pierre Guillard (Spitzer Science Center, IPAC, Caltech)
The build-up of baryonic mass in galaxies is regulated by a complex interplay between gravitational collapse, galaxy merging and feedback related to AGN and star formation. Although numerical simulations provide an increasingly detailed picture of the mass build-up, they remain schematic in their description of the dissipative processes that regulate star formation. To make headway in our understanding of galaxy evolution, we must answer the question: how is infall and feedback energy dissipated? Mid-IR Spitzer spectroscopy has unraveled an unexpected facet of this question by showing that the dissipation of kinetic energy involves the formation and dynamical heating of molecular gas, on galactic scales. I will discuss the discovery of a new class of nearby galaxies with bright H2 line emission, which does not seem associated with star formation but powered by the dissipation of large amounts of kinetic energy through shocks in warm molecular gas. I will show that JWST will be a unique tool to characterize the passage from molecular to stars in these nearby sources, and extend these studies at high redshifts.
Dr. Heidi Hammel (AURA)
A variety of solar system observations will be enabled by the infrared optimization of the James Webb Space Telescope. This talk will focus on mid-infrared observations of ice giant atmospheres. Infrared observations of Uranus and Neptune provide a rich laboratory for studies of molecular emission that trace tropospheric and stratospheric composition, as well as temperature and dynamics. A brief overview of other solar system topics will be also presented.
Thomas Henning (MPI for Astronomy)
The talk will review our present understanding of the gas content and its evolution in protoplanetary disks. During the last decade most of our knowledge on disks around young stars was provided by sensitive dust continuum observations and infrared spectroscopy. These data led to a much improved knowledge on disk structure, grain growth, and dust disk lifetimes. However, most of the mass in protoplanetary disks is not in the dust grains, but in the gas. It is this mass reservoir which is needed for the formation of giant planets and which is driving angular momentum and mass transfer in disks. Only very recently, we have started to explore the molecular content of inner disks with Spitzer spectroscopy and high-resolution data from the ground. In addition, Herschel observations and millimeter interferometry data are providing important information on the gas evolution in outer disks. I will summarize the status of our knowledge and will discuss why JWST will be an important facility in this rapidly growing field.
Jason Kalirai (STScI)
Nearby resolved stellar populations such as Galactic star clusters anchor our understanding of the Universe. Clusters are ideal testbeds to advance our knowledge of stellar evolution and structure, and provide a calibration of astrophysical relations that aim to interpret light across the Universe. Yet, over the past century of work, most of this effort has focused on visible light investigations given the lack of a high-resolution, sensitive, and wide-field infrared facility. This talk will highlight the unchartered discovery space that JWST will explore through ultra-deep IR imaging and MOS spectroscopy of nearby resolved stellar populations. Hints of the potential of these observations for advancing our knowledge of stellar relations based on very recent HST WFC3/IR imaging will also be presented.
Shri Kulkarni (Caltech)
Massive stars (say those with mass greater than ZAMS 90 Msun) could have several different channels for their end. The simplest is a "pair-instability" supernova in which the hot core becomes unstable to formation of electron-positron pairs and is completely obliterated. Some may undergo almost cataclysmic pulsations in their final years and then explode. Interaction of the blast wave with the rich cirumstellar medium then result in spectacularly bright supernovae ("Type IIn" or "luminous supernovae of Type Ic"). In some of these there could be a powerful central engine (e.g. magnetar) which could boost the luminosity and total energetics. Surveys of the narby Universe are revealing the expected richness. Examples include 2006gy (IIn), 2005ap/PTF09cnd (luminous SN of Type Ic)and 2007bi (pair-instability). We will summarize recent findings from the ROTSE-III, Palomar Transient Factory and Catalina Sky Survey. It is possible that these supernovae, though found at low redshift $z<0.5$ are excellent harbingers of the supernovae one expects to be prevalent in the early Universe. The local sample provides a basis to predict observational signatures of supernovae that will be discovered by JWST.
Crystal Martin (UCSB)
On the largest physical scales, the heavy elements in the Universe are distributed like galaxies. These filamentary structures were shaped by gravity and dark energy. On circumgalactic scales, in contrast, the baryons that have been processed through stars (i.e., metals) are much more smoothly distributed than galaxies. This web of metals surrounding galaxies indicates that galactic winds play a central role in shaping galaxies. The James Webb Space Telescope will provide new opportunities for examining the physical processes that weave this circumgalactic web of enriched material. From its vantage point above the earth’s atmosphere, Webb’s access and sensitivity to line emission in the near infrared will be timely and unique. The NIRSpec, MIRI, FGS-TF, and NIRCAM instruments all offer modes of observation well-suited to measuring line emission. The spectral multiplexing and mapping abilities of NIRSpec stand out, however, as exceptionally powerful tools for shaping a new picture of how circumglactic webs were woven. The spectral multiplexing capabilities of the MSA will enable galaxy surveys that reveal how rest-frame optical spectra evolve over cosmic time. The potential to trace the evolution of the galactic mass - metallicity relation down to z ≃ 0.52 will be of particular relevance for the evolution of metals in galaxies and the circumgalactic medium. The decline in galactic metallicity with decreasing mass can be attributed to metals escaping more easily from low mass galaxies. The evolution in this relation over cosmic time provides one way of viewing the history of circumgalactic enrichment. The derived metallicities will be subject, however, to systematic errors associated with integrated spectra, which blur together different regions of a galaxy. The capability to map spectral changes across complex objects will provide new insight into how circumgalatic webs form. To obtain a preview of the physical richness that Webb will discover with 3D-spectroscopy on kiloparsec scales, recent ground-based observations that have mapped spectral features across galaxies will be reviewed. The spectral variations measured across extreme starbursts at z < » 0.1, for example, provide guidance from the perspective of local analogs to high-redshift galaxies. In addition, due to recent advances in adaptive optics, integral-field spectroscopy is now informing our expectations directly by mapping high redshift galaxies at comparable spatial resolution. One exciting outcome of this work is the realization that galactic outflows can be identified in optical emission lines. This statement comes as a surprise because the H II regions in a star-forming galaxy are generally much brighter than the optical emission-line luminosity from a starburst-driven outflow. The poor contrast of the outflow follows directly – 2 – from the high luminosity of the Lyman continuum, which powers the H II regions, relative to the mechanical power supplied by massive stars. In the Galactic Neighborhood, optical line emission from outflows is easily recognized in edge-on galaxies because this galactic background is minimized geometrically. The emission-line spectrum of the outflow presents increasingly shock-like line ratios with increasing distance from the starburst region. Recent work suggests that a combination of kinematic and excitation diagnostics can be used to identify winds via 3D-spectroscopy at a spatial resolution of just ≃ 1 kpc, similar to the capabilities of the NIRSpec integral field unit over a very broad redshift range. One of the principle motivations for identifying outflows is of course to gain further physical insight into the strength of galactic winds; and mapping line emission provides the data required to measure a number of physical properties. Electron temperatures and densities, derived for example from forbidden lines, will constrain the thermal pressure. Comparison of the electron density to the root-mean-square electron density (derived from a hydrogen recombination line) would determine the volume filling factor of warm gas. The implied mass of warm gas would be uncertain by at least an order of magnitude without knowledge of the filling factor and spatial scale of the emission region; and the accuracy of the mass loss rate estimate improves when shock speeds (fitted to the emission-line ratios) can be mapped across the outflow. The values of the pressure and filling factor inferred for the warm phase of the outflow could also be used to argue about the presence or absence of a much hotter phase – a galactic wind – as seen via X-ray spectral imaging of galaxies in the Galactic Neighborhood. Given the variety of physical mechanisms proposed to accelerate outflows, it is not at all clear whether the warm phase carries the bulk of the outflowing mass or simply marks a phenomenon operating over a broad temperature range – much like an iceberg marks a more massive structure. Mapping physical properties across outflows in galaxies selected from a very broad range in stellar mass, environment, and redshift should provide new, fundamental insight about how and when feedback processes operate in galaxies. The circulation of metals describes the emerging theoretical picture of the circumgalactic web better than does wind or feedback. Metals ejected from the first galaxies are likely reaccreted in part by subsequent generations of galaxies. The galaxy disks, according to cosmological models, are replinished with gas semi-continuously through cold streams of infalling gas. Signatures of these inflows such as turbulence, shocks, or violent gravitational instability should be recognizable in these emission-line maps (in addition to outflows). A NIRSpec campaign can test for these inflows over a wider range in galaxy mass and redshift than can AO-assisted observations from the ground. Confirmation of the idea that cosmological inflow regulates the star formation rate in galaxies would solve a longstanding fundamental question, namely ‘What regulates the star formation rate in galaxies over cosmic time?’.
Michael Meyer (ETH Institute for Astronomy)
I will present several high risk projects that can be undertaken with the James Webb Space Telescope (JWST) that address critical questions in star and planet formation: 1) how common are stars like the Sun in the Milky Way and other galaxies? and 2) how common are planetary systems like our own? The highlighted projects take advantage of the unique attributes of JWST compared to other facilities: a) thermal infrared sensitivity; and b) high angular resolution over a wide field of view. We will focus in particular on JWST's ability to assess the dynamics of young star clusters, study the IMF in confusion-limited regions of extreme star formation in the Local Group, and search for hot proto-planet collision afterglows around young stars.
Prof. Alexandra Pope (University of Massachusetts Amherst)
I will discuss several exciting capabilities for using JWST to study galaxy formation and evolution. The Spitzer Space Telescope has set the stage for such pursuits by extending the detailed mid-IR spectroscopic study of small dust grains beyond our local Universe out to z~4. Most of the star formation activity in galaxies at z~2-4 is obscured by dust; JWST will allow us to push past this vail of dust to study star formation in galaxies much further down the infrared luminosity function. The mid-infrared regime contains powerful diagnostics for disecting the relative contribution to of active star formation and active galactic nuclei activity in addition to constraining the conditions of the interstellar medium. I will discuss the synergy of these JWST projects with current and future observations at longer wavelengths such as those with the Herschel Space Observatory and the Atacama Large Millimeter Array (ALMA).
Dr. Adam Riess (STScI/JHU)
The Hubble constant remains one of the most important parameters in the cosmological model, setting the size and age scales of the Universe. Present uncertainties in the cosmological model including the nature of dark energy, the properties of neutrinos and the scale of departures from flat geometry can be constrained by measurements of the Hubble constant made to higher precision that was possible with the first generations of Hubble Telescope instruments. Streamlined distances ladders constructed from infrared observations of Cepheids and type Ia supernovae with ruthless attention to systematics provide the means to reach percent level precision. While WFC3 has helped open this new route, its full exploitation can come from GAIA which will calibrate Cepheids from parallax to better than 1% and JWST which can calibrate the luminosity of SNe Ia to better than 1% by observing Cepheids in their hosts to 60 Mpc in the infrared. I will review recent and expected future progress.
Dr. Jane Rigby (NASA/GSFC)
I'll discuss several ways in which JWST will probe accretion onto supermassive black holes over cosmic time. Spitzer spectroscopy has demonstrated these techniques locally; JWST will push them into to the era of galaxy assembly.
Prof. Alice Shapley (UCLA)
JWST and the NIRSpec instrument provide important constraints on the cycling of baryons into, within, and outside of galaxies. Here we broadly outline two observing programs based on measurements of the rest-frame optical emission-lines originating in warm, ionized gas. These observing programs will directly probe the heavy-element content of star-forming galaxies at z>1, as well as potentially mapping out the full extent of outflowing (and perhaps inflowing) gas in the vicinity of galaxies as they are being assembled. Chemical Enrichment: The chemical enrichment of the interstellar medium of galaxies as a function of cosmic time provides a key and complementary window into the past history of star formation, modulated by the effects of gas inflow (i.e. gas accretion) and outflow (i.e. feedback from star formation or black-hole accretion). Most results about the metal content of high-redshift galaxies are based on measurements of rest-frame optical emission lines from H II regions, which are used to infer the gas-phase oxygen abundance. These include combinations of hydrogen recombination lines (H-alpha, H-beta), and collisionally excited forbidden lines from heavy elements such as oxygen ([OIII], [OII]), nitrogen ([NII]), and neon ([NeIII]). Much progress has been made over the last decade in terms of assembling rest-frame optical emission-line measurements probing the metal content and physical conditions in z>1 star-forming galaxies, and relating these measurements to both measured stellar masses and star-formation rates. Preliminary results suggest the existence of a mass-metallicity relationship at z~2-3, which has important implications for models of galactic outflows and and accretion. However, the current datasets from near-IR slit and integral field spectrographs on 8-10-meter-class ground-based telescopes are just scratching the surface. Beyond z~1, the number of individual objects with multiple rest-frame optical emission-line measurements is less than 100. Furthermore, there are no robust measurements of HII-region metallicity at z~4 and beyond, given the prohibitive level of the thermal background setting in at roughly 2.4 microns. Finally, given several gaps in atmospheric transmission between 1 and 5 microns (between the J, H, K, L, and M bands), certain key redshift ranges between z~1 and z~4 are simply inaccessible for rest-frame optical spectroscopy from the ground. In order to trace out a continuous history of metal enrichment, and to extend it into the reionization epoch beyond z~6, we must use NIRSpec on JWST. NIRSpec operated in Micro-Shuttle Assembly (MSA) and Integral-Field Unit (IFU) modes at intermediate resolution (R=1000,2700) will allow for extremely sensitive measurements of rest-frame optical emission-line fluxes, as well as mapping detailed enrichment gradients on kpc scales. The requirements for measuring strong-line metallicity indicators at z>=4 are based on the detection of the weakest features of interest, typically [NII]. The weak feature must be detected over an interesting dynamic range of line ratios with respect to one of the strongest rest-frame optical features, typically H-alpha, which can be predicted from the star-formation rate of a galaxy target. At z~6, in a 10^4 second exposure with NIRSpec (R=1000) it will be possible to detect [NII]/H-alpha ratios of ~1/10, for an object with a SFR=10 M_sun/year (neglecting the effects of dust extinction). At z~5 [4,3,2], it will be possible to detect the same [NII]/H-alpha line ratio for objects with SFR=7 [5,3,1] M_sun/year. At the same time, for objects over this redshift range, it is imperative to measure [OIII], H-beta, and [OII] emission lines. These offer an independent estimate of metallicity, ionization conditions, and dust extinction. Multiple gratings (2-3) will be required to obtain the full set of rest-frame optical emission lines for objects at z>1, yet the stability of JWST should limit the systematics in combining non-simultaneous observations. In addition to the basic goal of extending the chemical enrichment studies of the universe to larger redshifts, and over a wider dynamic range of line-ratio properties than can be achieved from the ground, there are a couple of challenging related avenues to pursue. One is the measurement of so-called ``direct" metallicities, based on an actual determination of the electron temperature from the ratio of an auroral feature such as [OIII] 4363 and the stronger [OIII] 5007 line. A direct metallicity measurement has only been achieved for a single, gravitationally-lensed object at z>1. However, with the assumption of an [OIII] 4363/[OIII] 5007 line ratio of ~30 (fair for moderately-enriched but subsolar galaxies), it should be possible to detect [OIII] 4363 and determine direct chemical abundances for galaxies at z~2 with star-formation rates of only a few M_sun/year, and at z>4 for objects with star-formation rates > 10 M_sun/year. Finally, recent estimates of chemical abundance gradients for star-forming galaxies at z~2-3 using ground-based IFU measurements appear to suggest conflicting results, with both negative and positive abundance gradients reported. Abundance gradients potentially offer additional constraints on the inflow and outflow of gas, and the build-up of the galaxy stellar population. The stability and sensitivity of the JWST/NIRSpec IFU mode will allow such observations to be performed over a wider redshift range, with higher spatial resolution. Emission-line probes of extended (outflowing/inflowing) gas: We also propose a related program with the JWST/NIRSpec IFU (R=1000) to study the dispersal of gas and heavy elements from star-forming galaxies at high-redshift. The canonical image of a nearby starburst galaxy is that of M82, which sustains a large-scale galactic outflow perpendicular to its star-forming disk. The outflow is dramatically traced by extended H-alpha emission from ionized gas. In contrast, the vast majority of rest-frame optical spectroscopy at high redshift z>2 has been geared towards detecting and characterizing the virialized motions of high-surface-brightness regions tracing star formation within galaxies, as opposed to extended, outflowing (or infalling) gas. In order to probe the extent, geometry, and dynamics of circumgalactic gas at high-redshift, we propose a program using the JWST/NIRSpec IFU to map extended H-alpha emission intensity and kinematics. So far, at z>2, extended emission-line regions around powerful radio galaxies have been mapped in this fashion. However, the mechanisms propelling and exciting that gas may be very different from the processes relevant for less luminous, star-formation-dominated systems. Blueshifted ionized emission-line gas potentially associated with an outflow has also been studied spectroscopically in non-AGN systems at z~2. However, no detailed map yet exists of this extended, diffuse ionized gas, nor a probe of its kinematics (either outflow or infall). The surface brightness of such extended emission is rather uncertain, and will determine the feasibility of obtaining useful constraints on its properties with JWST/NIRSpec.
Prof. Tommaso Treu (University of California Santa Barbara)
The standard cosmological model successfully reproduces the properties of the universe on supergalactic scales. However, it is unclear whether it can match the detailed properties of galaxies themselves. Open problems � such as the discrepancy between the number of observed satellites around the Milky Way and those expected based on numerical simulations, and the shallower than predicted dark matter density profiles observed in some galaxies and clusters of galaxies � suggest that our understanding is incomplete. To further complicate matters, in the past decade it has become clear that supermassive black holes might be an essential ingredient to solve this puzzle: they are found ubiquitously at the center of spheroidal galaxies and their mass correlates with global properties of the host, and possibly the dark matter halo. A unified description of dark matter, baryons, and black holes seems thus necessary to explain the observed correlations, and could perhaps reconcile the standard model with the con�icting observations. If this attempt fails, we might be forced to reconsider some of the standard features of the cosmological model, such as the nature or interactive properties of the dark matter. I will present an observational program, based on imaging and spectroscopy of multiply imaged quasars, that will address three major open questions in galaxy formation and evolution: 1) Do galaxies have as many satellites as predicted by numerical cold dark matter simulations? 2) How does the relation between black hole mass and host galaxy property evolve over cosmic time? 3) Are dark matter halos of massive elliptical galaxies consistent with the predictions of cold dark matter simulations, and how do they evolve over cosmic time? The first question will be answered by imaging a large sample of lensed quasars at 10 micron using MIRI, and studying the incidence of so-called "�ux ratio anomalies". Multiple image �ux ratios are a measurement of the magnification ratios, which is related to the second derivative of the gravitational potential. Observed ratios are often significantly different from those predicted by smooth galaxy models. These "anomalies" are usually explained in terms of small perturbations to the potential arising from microlensing (stars in the lens galaxy) or millilensing (satellites of the lens galaxy). At the typical lensed quasar redshift z=3-4 10 micron correspond to the dusty torus region. The size of the dusty torus is too large to be affected by microlensing and therefore it is considered an extremely clean probe of satellites. The effect is purely gravitational and therefore 1 the method can detect satellites irrespective of their luminosity (follow-up imaging with JWST at NIR wavelength should detect stars in the satellites if present - thus constraining their mass-to-light ratio). At the moment this technique is limited by the small number of lensed quasars that are bright enough ( 10 mJy) to be imaged in the mid-infrared from the ground (where resolution is sufficient). JWST sensitivity will revolutionize the field, making samples of 100s lensed QSOs practical, and therefore allowing for a full characterization of the mass function of the satellites. The second question will be answered by taking integral field spectra with NIRSPEC of the QSO host galaxy. The lensing magnification will enhance the contrast between the host galaxy and the point source enabling a direct measurement of the stellar velocity dispersion and velocity field via absorption features. For typical redshifts z=3-4 the MgFe region falls near the peak efficiency of grism G235H, which has sufficient resolution and wavelength coverage for this application. Considering typical host galaxies of QSOs, extrapolated to these redshifts, a few hours per target will be required. The same spectra will also measure with high fidelity emission lines from the narrow line region (NLR) of the active galactic nuclei. Although they are not accurate probes of the overall gravitational potential of the host galaxy, the will provide an interesting additional probe of substructure in the lens plane. In fact, since the NLR is fully resolved by JWST it is unaffected by microlensing. However, substructure in the lens plane introduces astrometric perturbations in the lensed images and can therefore be detected using a technique called "gravitational imaging". The same IFU spectra used to answer the second question will also answer the third question by enabling accurate mass models of the foreground galaxy using gravitational lensing and stellar kinematics. Integral field spectra of emission lines in the source are an ideal input for modeling the foreground gravitational potential for two reason: i) constructing emission line images at the appropriate wavelengths solves the problem of disentangling light from the source by contamination from the foreground detector; ii) lensing is achromatic and therefore the centroid of the emission line provides an additional constraint on the mass model, in addition to its intensity. In addition, for a typical redshift of the foreground lens CO bandheads or the near infrared Calcium triplet will fall into the NIRSPEC G235H wavelength range enabling the measurement of its stellar velocity dispersion. 2
Jeff Valenti (STScI)
JWST will discover and characterize exoplanets with a diverse complement of coronagraphs and spectrometers. Three science instruments have coronagraphs (Lyot, four-quadrant phase, and a non-redundant mask) that will image giant planets at separations less than an arcsec. Observations of nearby stars and more distant young stars will constrain models of giant planet formation and migration in the outer disk. Three science instruments have dispersers (spectral resolving powers between 50 and 3000) that will characterize the bulk properties and atmospheres of transiting/eclipsing planets. Spectral resolution will be two orders of magnitude higher than possible with existing instrumentation, yielding new constraints on atmospheric composition, thermal balance as a function of height and longitude, non-equilibrium chemistry, and cloud formation. JWST can characterize a large number of known exoplanets. The sample will increase by a factor of a few in the lifetime of JWST. A complete census of planets that transit bright stars would identify the best targets for followup by JWST. JWST operations will affect how exoplanet observations are obtained. Field of regard, roll constraints, and slew times will limit flexibility, but the sunshield will make JWST quite stable thermally. Detectors will be programmed to obtain data efficiently throughout an eclipse/transit. Up-the-ramp readout of the infrared detectors will permit cosmic ray rejection on the ground. Precision will be affected by pointing drift and intra-pixel sensitivity variations, but the ultimate limit is not yet known.
Dr. Daniel Whalen (Carnegie Mellon University)
The first stars in the universe are key to the rise of primeval galaxies, early cosmological reionization, and the formation of the supermassive black holes found in most massive galaxies today. Unfortunately, because they lie near the edge of the observable universe, there are no direct observational constraints on their masses. However, their supernovae will soon be visible to JWST. I will present the first comprehensive suite of radiation hydrodynamical calculations of the light curves and spectra of Pop III SNe ever performed, which include both core-collapse and pair-instability explosions. I will also discuss their detection threshold in redshift by JWST and how strong gravitational lensing extends this threshold to earlier epochs. Finally, I will describe how early spectroscopy can discriminate between core-collapse and pair-instability explosions and thus probe the Pop III IMF.
Christine Wilson (McMaster University)
Our understanding of star formation has advanced dramatically in recent years with detailed studies from the Spitzer Space Telescope in the near and mid-infrared and the Herschel Space Observatory in the far-infrared and submillimeter. In my talk, I will focus on what we will be able to learn using the MIRI instrument on the JWST. I will discuss in detail an example drawn from studies of massive star formation in the Milky Way as well as an example focusing on a giant HII region in the Local Group.