The James Webb Space Telescope (JWST) will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its ...predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010. It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV, in 2012.
HST and IUE spectra and photometry, as well as optical spectra of the Type Ia supernova SN 1992A in the S0 galaxy NGC 1380 obtained at the CTIO are presented. The UV photometry taken in the F175W, ...F275W, and F342W bands defined by the HST filters shows light curves that resemble the Type Ia template U light curve. Data from SN 1992A and SN 1990N are used to construct a Type Ia template light curve for the flux region near 2750 A that is quite detailed from 14 d before maximum light to 22 d after maximum light and that extends to 77 d after maximum light. The features in the region blueward of about 2650 A in the HST spectra are found to be P Cygni absorptions due to blends of ion peak element multiplets and the Mg II resolution multiplet. It is inferred that the oxygen-rich layer in typical Type Ia's extends over a velocity range of at least about 11,000-19,000 km/s. (AIAA)
The Far Ultraviolet Spectroscopic Explorer (FUSE) has allowed precise determinations of the column densities of molecular hydrogen (H{sub 2}) in Galactic lines of sight with a wide range of ...pathlengths and extinction properties. However, survey studies of lines of sight with greater extinction have been mostly restricted to the low-J states (lower total angular momentum) in which most molecular hydrogen is observed. This paper presents a survey of column densities for the molecular hydrogen in states of greater rotational excitation (J >= 2) in Galactic lines of sight with log N(H{sub 2}) {approx}> 20. This study is comprehensive through the highest excited state detectable in each line of sight. J = 5 is observed in every line of sight, and we detect J = 7 in four lines of sight, J = 8 in one line of sight, and vibrationally excited H{sub 2} in two lines of sight. We compared the apparent b-values and velocity offsets of the higher-J states relative to the dominant low-J states and we found no evidence of any trends that might provide insight into the formation of higher-J H{sub 2}, although these results are the most affected by the limits of the FUSE resolution. We also derive excitation temperatures based on the column densities of the different states. We confirm that at least two distinct temperatures are necessary to adequately describe these lines of sight, and that more temperatures are probably necessary. Total H{sub 2} column density is known to be correlated with other molecules; we explore if correlations vary as a function of J for several molecules, most importantly CH and CH{sup +}. Finally, we briefly discuss interpretations of selected lines of sight by comparing them to models computed using the Meudon PDR code.
We present new Hubble Space Telescope images of high-velocity H alpha and Ly alpha emission in the outer debris of SN 1987 A. The Ha images are dominated by emission from hydrogen atoms crossing the ...reverse shock (RS). For the first time we observe emission from the RS surface well above and below the equatorial. ring (ER), suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H alpha imaging, we measure the mass flux of hydrogen atoms crossing the RS front, in the velocity intervals (-7500 < V-obs < -2800 km s(-1)) and (1000 < V-obs < 7500 km s(-1)), (M)(H) over dot = 1.2 x 10(-3) M-circle dot yr(-1). We also present the first Ly alpha imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Ly alpha and X-ray emission, we observe that the majority of the high-velocity Ly alpha emission originates interior to the ER. The observed Ly alpha/H alpha photon ratio, < R(L alpha/H alpha)> approximate to 17, is significantly higher than the theoretically predicted ratio of approximate to 5 for neutral atoms crossing the RS front. We attribute this excess to Ly alpha emission produced by X-ray heating of the outer debris. The spatial orientation of the Ly alpha and X-ray emission suggests that X-ray heating of the outer debris is the dominant Ly alpha production mechanism in SN 1987 A at this phase in its evolution.
The James Webb Space Telescope (JWST) will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its ...predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010. It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV, in 2012.
Observations with the Hubble Space Telescope (HST), conducted since 1990, now offer an unprecedented glimpse into fast astrophysical shocks in the young remnant of supernova 1987A. Comparing ...observations taken in 2010 with the use of the refurbished instruments on HST with data taken in 2004, just before the Space Telescope Imaging Spectrograph failed, we find that the Lyα and Hα lines from shock emission continue to brighten, whereas their maximum velocities continue to decrease. We observe broad, blueshifted Lyα, which we attribute to resonant scattering of photons emitted from hot spots on the equatorial ring. We also detect N v λλ1239, 1243 angstrom line emission, but only to the red of Lyα. The profiles of the N v lines differ markedly from that of Hα, suggesting that the N⁴⁺ ions are scattered and accelerated by turbulent electromagnetic fields that isotropize the ions in the collisionless shock.
We present the analysis of supernova remnants (SNRs) in the Large Magellanic Cloud (LMC) and their influence on the environment at far-infrared (FIR) and submillimeter wavelengths. We use new ...observations obtained with the Herschel Space Observatory and archival data obtained with the Spitzer Space Telescope, to make the first FIR atlas of these objects. The SNRs are not clearly discernible at FIR wavelengths; however, their influence becomes apparent in maps of dust mass and dust temperature, which we constructed by fitting a modified blackbody to the observed spectral energy distribution in each sightline. Most of the dust that is seen is pre-existing interstellar dust in which SNRs leave imprints. The temperature maps clearly reveal SNRs heating surrounding dust, while the mass maps indicate the removal of 3.7+7.5-2.5 M ☉ of dust per SNR. This agrees with the calculations by others that significant amounts of dust are sputtered by SNRs. Under the assumption that dust is sputtered and not merely pushed away, we estimate a dust destruction rate in the LMC of 0.037+0.075-0.025 M ☉ yr-1 due to SNRs, yielding an average lifetime for interstellar dust of 2+4.0-1.3× 10^7 yr. We conclude that sputtering of dust by SNRs may be an important ingredient in models of galactic evolution, that supernovae may destroy more dust than they produce, and that they therefore may not be net producers of long lived dust in galaxies.
ABSTRACT We present new Hubble Space Telescope images of high-velocity H and Ly emission in the outer debris of SN 1987 A. The H images are dominated by emission from hydrogen atoms crossing the ...reverse shock (RS). For the first time we observe emission from the RS surface well above and below the equatorial ring (ER), suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H imaging, we measure the mass flux of hydrogen atoms crossing the RS front, in the velocity intervals (−7500 < Vobs < −2800 km s−1) and (1000 < Vobs < 7500 km s−1), = 1.2 × 10−3 M yr−1. We also present the first Ly imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Ly and X-ray emission, we observe that the majority of the high-velocity Ly emission originates interior to the ER. The observed Ly /H photon ratio, 17, is significantly higher than the theoretically predicted ratio of 5 for neutral atoms crossing the RS front. We attribute this excess to Ly emission produced by X-ray heating of the outer debris. The spatial orientation of the Ly and X-ray emission suggests that X-ray heating of the outer debris is the dominant Ly production mechanism in SN 1987 A at this phase in its evolution.
PDF
