Spectroscopic Capibilities and Possibilities of the Far Infrared and Submillimeter Telescope Mission
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A series of three Hubble Space Telescope Space Telescope Imaging Spectrograph (HST/STIS) spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from η Carinae. We identify these arcs with the shell-like structures, seen in the 3D hydrodynamical simulations, formed by compression of the primary wind by the secondary wind during periastron passages.
SDSS J2222+2745 is a galaxy cluster at z = 0.49, strongly lensing a quasar at z = 2.805 into six widely separated images. In recent Hubble Space Telescope imaging of the field, we identify additional multiply lensed galaxies and confirm the sixth quasar image that was identified by Dahle et al. We used the Gemini-North telescope to measure a spectroscopic redshift of z = 4.56 of one of the lensed galaxies. These data are used to refine the lens model of SDSS J2222+2745, compute the time delay and magnifications of the lensed quasar images, and reconstruct the source image of the quasar host and a lensed galaxy at z = 2.3. This galaxy also appears in absorption in our Gemini spectra of the lensed quasar, at a projected distance of 34 kpc. Our model is in agreement with the recent time delay measurements of Dahle et al., who found T(sub AB) = 47.7 +/- 6.0 days and T(sub AC) = 722 +/- 24 days. We use the observed time delays to further constrain the model, and find that the model-predicted time delays of the three faint images of the quasar are T(sub AD) = 502+/- 68 days, T( sub AE) = 611 +/- 75 days, and T(sub AF) = 415 +/- 72 days. We have initiated a follow-up campaign to measure these time delays with Gemini North. Finally, we present initial results from an X-ray monitoring program with Swift, indicating the presence of hard X-ray emission from the lensed quasar, as well as extended X-ray emission from the cluster itself, which is consistent with the lensing mass measurement and the cluster velocity dispersion.
We present near-infrared spectra for 144 candidate planetary systems identified during Campaigns 1-7 of the NASA K2 Mission. The goal of the survey was to characterize planets orbiting low-mass stars, but our Infrared Telescope Facility/SpeX and Palomar/TripleSpec spectroscopic observations revealed that 49% of our targets were actually giant stars or hotter dwarfs reddened by interstellar extinction. For the 72 stars with spectra consistent with classification as cool dwarfs (spectral types K3-M4), we refined their stellar properties by applying empirical relations based on stars with interferometric radius measurements. Although our revised temperatures are generally consistent with those reported in the Ecliptic Plane Input Catalog (EPIC), our revised stellar radii are typically 0.13 solar radius (39%) larger than the EPIC values, which were based on model isochrones that have been shown to underestimate the radii of cool dwarfs. Our improved stellar characterizations will enable more efficient prioritization of K2 targets for follow-up studies.
Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and Exo-Earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling it.
Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.
Context . The Gl 486 system consists of a very nearby, relatively bright, weakly active M3.5V star at just 8 pc with a warm transiting rocky planet of about 1.3 R ⨁ and 3.0 M ⨁ . It is ideal for both transmission and emission spectroscopy and for testing interior models of telluric planets. Aims . To prepare for future studies, we aim to thoroughly characterise the planetary system with new accurate and precise data collected with state-of-the-art photometers from space and spectrometers and interferometers from the ground. Methods . We collected light curves of seven new transits observed with the CHEOPS space mission and new radial velocities obtained with MAROON-X at the 8.1m Gemini North telescope and CARMENES at the 3.5m Calar Alto telescope, together with previously published spectroscopic and photometric data from the two spectrographs and TESS. We also performed near-infrared interferometric observations with the CHARA Array and new photometric monitoring with a suite of smaller telescopes (AstroLAB, LCOGT, OSN, TJO). This extraordinary and rich data set was the input for our comprehensive analysis. Results . From interferometry, we measure a limb-darkened disc angular size of the star Gl 486 at θ LDD = 0.390 ± 0.018 mas. Together with a corrected Gaia EDR3 parallax, we obtain a stellar radius R * = 0.339 ± 0.015 R ⨀ . We also measure a stellar rotation period at P rot = 49.9 ± 5.5 days, an upper limit to its XUV (5–920 Å) flux informed by new Hubble/STIS data, and, for the first time, a variety of element abundances (Fe, Mg, Si, V, Sr, Zr, Rb) and C/O ratio. Moreover, we imposed restrictive constraints on the presence of additional components, either stellar or sub-stellar, in the system. With the input stellar parameters and the radial-velocity and transit data, we determine the radius and mass of the planet Gl 486 b at R p = 1.343 +0.063 -0.062 R ⨀ and M p = 3.00 +0.13 -0.13 M ⨁ , with relative uncertainties of the planet radius and mass of 4.7% and 4.2%, respectively. From the planet parameters and the stellar element abundances, we infer the most probable models of planet internal structure and composition, which are consistent with a relatively small metallic core with respect to the Earth, a deep silicate mantle, and a thin volatile upper layer. With all these ingredients, we outline prospects for Gl 486 b atmospheric studies, especially with forthcoming James Webb Space Telescope (Webb) observations.
The scientific rationale for the large deployable reflector (LDR) and the overall technological requirements are discussed. The main scientific objectives include studies of the origins of planets, stars and galaxies, and of the ultimate fate of the universe. The envisioned studies require a telescope with a diameter of at least 20 m, diffraction-limited to wavelengths as short as 30-50 micron. In addition, light-bucket operation with 1 arcsec spatial resolution in the 2-4 microns wavelength region would be useful in studies of high-redshifted galaxies. Such a telescope would provide a large increase in spectroscopic sensitivity and spatial resolving power compared with existing or planned infrared telescopes.
As part of a major study of the physical processes of star formation and the evolution of galactic discs, the detailed distribution of high-mass star formation within southern late-type spirals and Magellanic-type galaxies is being measured by means of narrow-band imaging in Ha and the continuum, spectroscopic studies of prominent HII regions identified in the Ha images, and by radio mapping in neutral hydrogen and the continuum. The radio mapping will be undertaken with the Southern Hemisphere's first large, multi-frequency synthesis array, the Australia Telescope. Some optical imaging and spectroscopic data has already been acquired; the optical data and some preliminary results are described.
The Astrophysics Division within the NASA Office of Space Science and Applications (OSSA) has defined a set of major and moderate missions that are presently under study for flight sometime within the next 20 years. These programs include the: Advanced X Ray Astrophysics Facility; X Ray Schmidt Telescope; Nuclear Astrophysics Experiment; Hard X Ray Imaging Facility; Very High Throughput Facility; Gamma Ray Spectroscopy Observatory; Hubble Space Telescope; Lunar Transit Telescope; Astrometric Interferometer Mission; Next Generation Space Telescope; Imaging Optical Interferometer; Far Ultraviolet Spectroscopic Explorer; Gravity Probe B; Laser Gravity Wave Observatory in Space; Stratospheric Observatory for Infrared Astronomy; Space Infrared Telescope Facility; Submillimeter Intermediate Mission; Large Deployable Reflector; Submillimeter Interferometer; and Next Generation Orbiting Very Long Baseline Interferometer.
The HST Treasury Program on eta Carinae produced one of the most complex and ambitious spectroscopic datasets obtained with the Hubble Space Telescope. The archival database includes the STIS/CCD and MAMA data during its recent spectroscopic event in 2003, plus all of the STIS observations of the object and its ejecta obtained during its spectroscopic cycle beginning in 1998. The database permits users to query via instrument, target, date, wavelength range, position angle, and position and allows the user to display the spectrum and download it in fits format. We have also developed software for ease of extraction and display and analysis. The user can go from an initial query to doing science in only 20 minutes! A demonstration of the database and software will be available at the poster.
The stellar occultation method has been successfully used in the past from orbiting observatories to measure concentrations of certain trace gases in the earth's mesosphere. The greatly improved spectroscopic capabilities of the Hubble Space Telescope (HST) have prompted recent suggestions for its use to measure stratospheric C10. This possibility is examined along with that for other species relevant to the chemistry of the ozone layer. It is concluded that stratospheric (as opposed to mesospheric) observations with HST are not practical, in part because of its orbital and pointing characteristics, but primarily because the high opacity of stratospheric ozone over most of the bandpass of the HST's most suitable spectrometer will obscure observation of other trace species, such as C10, having mixing ratios of less than 0.001.
We present a community-led assessment of the solar system investigations achievable with NASA's next-generation space telescope, the Wide Field Infrared Survey Telescope (WFIRST). WFIRST will provide imaging, spectroscopic, and coronagraphic capabilities from 0.43 to 2.0 m and will be a potential contemporary and eventual successor to the James Webb Space Telescope (JWST). Surveys of irregular satellites and minor bodies are where WFIRST will excel with its 0.28 deg2 field-of-view Wide Field Instrument. Potential ground- breaking discoveries from WFIRST could include detection of the first minor bodies orbiting in the inner Oort Cloud, identification of additional Earth Trojan asteroids, and the discovery and characterization of asteroid binary systems similar to Ida/Dactyl. Additional investigations into asteroids, giant planet satellites, Trojan asteroids, Centaurs, Kuiper belt objects, and comets are presented. Previous use of astrophysics assets for solar system science and synergies between WFIRST, Large Synoptic Survey Telescope, JWST, and the proposed Near-Earth Object Camera mission is discussed. We also present the case for implementation of moving target tracking, a feature that will benefit from the heritage of JWST and enable a broader range of solar system observations.
The Dark Energy Spectroscopic Instrument (DESI) is a massively parallel spectroscopic survey on the Mayall telescope at Kitt Peak, which has released measurements of baryon acoustic oscillations determined from over 14 million extragalactic targets. We combine DESI Data Release 2 with CMB datasets to search for evidence of matter conversion to dark energy (DE), focusing on a scenario mediated by stellar collapse to cosmologically coupled black holes (CCBHs). In this physical model, which has the same number of free parameters as ΛCDM, DE production is determined by the cosmic star formation rate density (SFRD), allowing for distinct early- and late-time cosmologies. Using two SFRDs to bracket current observations, we find that the CCBH model: accurately recovers the cosmological expansion history, agrees with early-time baryon abundance measured by BBN, reduces tension with the local distance ladder, and relaxes constraints on the summed neutrino mass ∑𝑚 𝜈 . For these SFRDs, we find a peaked positive ∑𝑚 𝜈 < 0.149 eV (95% confidence) and ∑𝑚 𝜈 = 0.106$^{+0.050}_{−0.069}$ eV, respectively, in good agreement with lower limits from neutrino oscillation experiments. A peak in ∑𝑚 𝜈 > 0 results from late-time baryon consumption in the CCBH scenario and is expected to be a general feature of any model that converts sufficient matter to dark energy during and after reionization.
The properties of stellar chromospheres are examined, summarizing the results of observations obtained with the IUE satellite since its launch in 1978. Numerous sample spectra, graphs, and diagrams are presented and analyzed in detail. Consideration is given to 120-320-nm spectroscopy of main-sequence stars, giants, and supergiants; the global properties of main-sequence and post-main-sequence chromospheres; dynamic phenomena and structures (systematic flows, atmospheric inhomogeneities, and intrinsic variability); and structural and energy-balance modeling. A number of outstanding problems are listed, and the potential value of data from the Hubble Space Telescope and the Lyman FUV Spectroscopic Explorer in solving them is indicated.
The radiation environment of near-earth space and its effects on biological and hardware systems are examined in reviews and reports. Sections are devoted to particle interactions and propagation, data bases, instrument background and dosimetry, detectors and experimental progress, biological effects, and future needs and strategies. Particular attention is given to angular distributions and spectra of geomagnetically trapped protons in LEO, bremsstrahlung production by electrons, nucleon-interaction data bases for background estimates, instrumental and atmospheric background lines observed by the SMM gamma-ray spectrometer, the GRAD high-altitude balloon flight over Antarctica, space protons and brain tumors, a new radioprotective antioxidative agent, LEO radiation measurements on the Space Station, and particle-background effects on the Hubble Space Telescope and the Lyman FUV Spectroscopic Explorer.
The search for organic materials on small bodies of the Solar System is conducted spectroscopically from Earth-based telescopes and from spacecraft. Although the carbonaceous meteorites carry a significant inventory of complex organic solids, the sources of these meteorites have not been identified. Infrared spectra of a sample of the suspected sources, the C- and D-class asteroids, including new data from the Spitzer Space Telescope, show signatures of silicates, but none diagnostic of organic compounds. In the absence of discrete spectral features, the low albedos and colors in the visible and near-IR spectral regions are the principal links between the organic-bearing meteorites and the asteroids. While Pluto and a few trans-neptunian objects show spectral signatures of frozen CH4. Solid CH3OH has been identified on two Centaur objects in the outer Solar System. In some cases the red colors of those objects suggest the presence of tholins. The VIMS instrument aboard the Cassini spacecraft in orbit around Saturn has detected near-IR spectral features on at least three of Saturn's satellites that are indicative or suggestive of organic molecules. One entire hemisphere of the satellite Iapetus is covered with low-albedo material that shows a spectral signature of aromatic hydrocarbons (3.3 microns) and the -CH2 stretching mode bands of an aliphatic component. Organics absorbing at 3.44 microns are suspected in the region of the south pole of Enceladus, and also on the surface of Phoebe. Organic material may originate on icy bodies in the current epoch by various processes of energy deposition into native material, or they may fall to the surface from an external (probably cometary) source. Some organic material may be pre-solar, having originated in the interstellar medium before the formation of the Solar System. Using the techniques of remote sensing, its detection and analysis are slow and difficult.
We have obtained Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope STIS spectra of HR 4796A, a nearby 8 Myr old main-sequence star that possesses a dusty circumstellar disk whose inclination has been constrained from high-resolution near-infrared observations to be 17 degrees from edge-on.