Status of the Emission Line Project Report to the Chandra Users Committee June 22, 2001 Nancy Brickhouse and Jeremy Drake 1. Fifteen Chandra ELP grants were awarded for the one-year period 11/16/99 to 11/15/00 from NASA administered by the CXC. Twelve of the final reports are completed; three have asked for no-cost extensions. Of these grants (average grant $10 K), 5 were laboratory, 8 theoretical, 2 database. Final reports to date show typically 1 to 3 refereed publications partially supported with these funds. Furthermore, the projects which produced atomic data are making their data available to the Astrophysical Plasma Emission Data (APED) (which can be accessed with CXC software). Laboratory work partially supported by ELP demonstrates (1) Theoretical dielectronic recombination rate coefficients for Fe L shell only accurate to factors of 2 (Savin); (2) Electron impact collision strengths for density diagnostics (Fe XIX to XXII) benchmarked at tokamak densities (Fournier); (3) Observations of Fe XVII line ratios from an EBIT with a microcalorimeter detector (Silver); Theoretical work includes: (1) R matrix calculations for hydrogenic and fluorine-like ions (Bhalla); (2) R matrix calculations for Fe XIX and XX (Kirby), to be applied to Chandra data; (3) Dielectronic recombination satellite line intensities and energies from high n levels (Safronova), already in APED; (4) R matrix calculations for Fe X, XI and XIII soft X-ray (Tayal), publicly available; (5) R matrix calculations for Fe XVII and XXV (Pradhan), in discussion of formats to make data available in APED; (6) A study of constructive and destructive effects on the electron impact cross sections in electron beam collisions with hydrogenic ions (Pindzola), supports experimental work; (7) Calculations for spectra of He-like ions, inner shell photoionization cross sections for Fe XV and OI, and recombination spectra for Li-like ions (Bautista), publicly available; Database work includes: (1) Upgrade to Chianti for H- and He-like ions, all data publicly available (Dere); (2) Critical evaluation of atomic probabilities for ions of interest to Chandra (Ne V - VIII; Mg V - X; Si V - XII; S VII - XIV) to be available via NIST website summer 2001 (Reader); The three no-cost extensions are for researchers (Beiersdorfer, Liedahl, Doschek) who are already in close contact with CXC staff. Laboratory wavelengths from the LLNL EBIT (Beiersdorfer, PI) are in APED, as are HULLAC calculations by Liedahl. 2. N. Brickhouse reported to the NRC Committee on Atomic, Molecular and Optical Sciences (July 2000) on problems associated with obtaining needed atomic data for astrophysical applications. The atomic data needed are no longer at the cutting edge of atomic physics, yet the astrophysics community (and other communities such as fusion energy) do not support the full range of atomic work it needs. The ELP is being considered as a case study for a collaborative approach to this interdisciplinary research. Small ELP grants were awarded for specific calculations or measurements from researchers primarily funded some other way. The idea was to use the small grants to leverage research on critical problems for applications. The NRC Committee is considering recommendations to help facilitate the interaction between data producers and data users. 3. Status of Chandra calibration data (Capella, Procyon, and HR 1099) for use in benchmarking plasma spectral codes. Chandra duties for the mission had to take precedence over the in-depth analysis of the Emission Line Project data. Nevertheless, the public availability of the Chandra data has allowed to date five refereed publications on preliminary results from these targets. Ongoing work on data analysis includes: (1) Reprocessing. The OAC data were given lowest priority for reprocessing, and some data sets are still not available in the archive (though custom processed products are available upon request to the CXC). Calibration data taken after OAC are all available. Custom processed data from the early phases of OAC revealed continuing problems with the order sorting tables due to ACIS gain calibration. Appropriate tables have been included in the CALDB over the last month. (2) Effective areas for HETG/ACIS and LETG/HRC-S are in good shape, with most spectral regions good to ~10 percent away from gaps and edges. (3) Background filtering of LETG/HRC-S has been studied. Optimized methods are now recommended on CIAO threads pages (2001 May 8). (4) The spectrograph is very stable: quantitative analysis is underway. (5) The effects of randomization on spectral line profiles are being studied. Randomization of positions occurs by default in the tg_extract_events tool. The purpose of this randomization is to minimize pattern noise caused by dithering; however, the randomization increases the line widths by about 10 percent. HEG line profiles are most seriously affected by both dithering and randomization because the pixel size is large compared to the spectral resolution (and thus the line profiles are not well sampled). A large number of line profiles do not appear to match the expected instrumental profile (e.g. many have 5 to 10 count divets in the middle of the line) and are thus difficult to measure. XRCF data demonstrate that the HEG profiles are approximately Gaussian; hence efforts are being made to understand how to recover the intrinsic line profiles. Scientific analysis of the data for benchmarking the plasma codes is also underway. Work in progress includes: (1) Comprehensive line lists from the OAC targets are being constructed, for posting 2001 Aug. 31. (2) Effects of line blending in diagnostic regions (Mg XI, Ne IX, and O VII). Initial results will be presented at Stellar Coronae 2001. (3) Comprehensive study of line-free regions needed to determine continuum levels. Initial results will be presented at Stellar Coronae 2001. (4) ``Missing line'' problem in Procyon is being quantified, in conjunction with EBIT data. (5) Initial comparisons with APED code for all targets will be posed by 2001 Dec 21.