AtomDB: X-ray Diagnostics of Astrophysical Plasmas

Transcription

1 AtomDB: X-ray Diagnostics of Astrophysical Plasmas Randall Smith Smithsonian Astrophysical Observatory

2 Collaborators and Thanks AtomDB Collaborators: Adam Foster, Nancy Brickhouse, John Raymond, Li Ji, Tim Kallman, Mike Witthoeft, Hiroya Yamaguchi, Joern Wilms Thanks to: ADAS team, CHIANTI team, ITAMP, Kate Kirby, Verne Jacobs, Ulyana Safronova, Guo- Xin Chen, Brendan McLaughlin, Brad Wargelin, and many others

3 Advertisement: LAD The Laboratory Astrophysics Division (LAD) The object of the Laboratory Astrophysics Division is to advance our understanding of the Universe through the promotion of fundamental theoretical and experimental research into the underlying processes that drive the Cosmos. Laboratory Astrophysics Division intended as an inclusive short name Includes Astrophysics, Planetary Sciences, Astrochemistry, Astrobiology, Membership questions: Brings users and providers together How to join: (Full/Associate versus Affiliate Members; Junior Members) To join the LAD listserv:

4 Introduction Unexpectedly strong solar X-rays were first detected on an August 5, 1948 flight (Burnight 1949, Phys Rev 76, 165). Combined with optical observations of the corona, models assuming it was a plasma at ~10 6 K were entertained"

5 X-ray Line Emission from Capella Abstract: X-ray emission-line components from Mg, Si, S, and Fe are unambiguously detected from Capella with the solidstate spectrometer onboard the Einstein Observatory. The X-ray spectrum is inconsistent with an isothermal corona, and requires components between 6- million K and at least 24-million K for an adequate fit. An inhomogeneous corona in which the X-ray emitting plasma is confined to magnetically contained loops appears to be reconcilable with all of the experimental evidence. Flux (cts/s/kev) Introduction Energy (kev) 7 ksec exposure with the Einstein Solid State Spectrometer (Holt et al. 1979)!

6 Introduction Coronal Structure and Abundances of Capella from EUVE and ASCA Spectroscopy! Abstract: (edited)! The plasma spectral emission models (Raymond-Smith, MEKAL, SPEX) around 1.2 kev appear to have flux deficits relative to the observed ASCA count spectrum. " New atomic models by Liedahl and Brickhouse dramatically improves the spectral model fits to the data, allowing reliable determination of elemental abundances." While a two-temperature model actually provides a better fit to the ASCA spectrum than the EUVE-derived continuous model, the EUVE data are not well fitted with only two temperatures. " We find that the abundances of Mg, Si, S, and Fe are consistent with solar photospheric values, while Ne appears to be underabundant by a factor of ~3 to 4." 21 ksec obs. w/asca Silicon Imaging Spectrometer (Brickhouse et al. 2000)

7 In this case, the poor fit between 9-12 Å is likely due to missing lines, not bad modeling. Introduction

8 Introduction High-Resolution X-Ray Spectra of Capella: Initial Results from the Chandra High- Energy Transmission Grating Spectrometer" 89 ksec w/chandra HETG (Canizares et al. 2000) Abstract (edited): Capella has plasma with a broad range of temperatures, from log T = 6.3 to 7.2, generally consistent with recent results from EUV/ASCA The electron density is determined from He-like O VII lines, giving the value of Ne cm -3 at Te K. The density and emission measure from O VII lines together indicate that the coronal loops are significantly smaller than the stellar radius.

9 A Few Words about X-ray Needs "Major needs are H-like, He-like, and Fe (and to a lesser extent Ni) L-shell line data." 400 Counts 200 Si XIV Si XIII Mg XII Mg XI Ne X Ne IX Ne IX Ne X Ne IX Fe XVII O VIII TW Hya, Chandra HETG Fe XVII O VII O VIII O VII Wavelength (Angstroms) Brickhouse et al. 2010

10 A Few Words about X-ray Needs Photoionized plasmas are more complex as both collisional and photon cross sections are relevant. " However, H-like, He-like, and Fe ions are still key (although other ions play a larger role)." NGC 3783 X-ray bright Seyfert galaxy; 900 ksec HETG, 280 ksec RGS observations Krongold et al. 2003; also Netzer et al and Behar et al. 2003

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12 AtomDB Astrophysical Models Theoretical and Laboratory Atomic Data (various formats) XSTAR PHASE APEC Wavelengths Atomic Structure Collisional Rate Coefficients AtomDB standard formats, evaluated data, accessible Sherpa/ CIAO XSPEC ISIS Analysis Tools Radiative Transition Rates Profit Photon Cross Sections Level Bundling Tool Database Tools WebGUIDE

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14 Advertisement: AtomDB WorkWeek 3 rd Annual Work CfA August (M-F) August 19, 20, 23: Informal daily collaborations August 21-22: 1.5 day conference on latest results Attendees include X-ray astrophysicists Atomic physicists (theory & experiment) AtomDB maintainers

15 Wavelengths Fit using raw HULLAC wavelengths Fit using lab (Brown et al. 1998) wavelengths Fit using newly calculated wavelengths Kotochigova et al 2010 By combining laboratory measurements and theoretical structure calculations, can get highly accurate (few må) wavelengths. Detectors with R>1000 require this kind of accuracy!

16 Current Problems: He-like "Data updated for He-like ions using an R-Matrix calculation for the levels up to n=5, and then extending that to n=10 using a distorted wave calculation. " Smith et al. 2009; Foster et al 2012

17 Current Problems: H-like )6.8019/:.:,707 0;5 % 3 "# "# #&#" <*0=0(.0"#70> 2.:5@A0)"&%&"?8 2.:5@A0)$&#&# Bandpass for Mg XI?8?8?8?8?8?8?8?8! "# "" "$ "% '()*+*,-./0123 Going to higher n-shell is needed and still an outstanding problem for all but H-like, He-like ions.

18 Current Problems: Fe XVII & 4C1-D:1/D121 EFFGH.I23-/D121 % Raymond-Smith AtomDB v ,-./012,3/$45$6 $ # AtomDB v2.0.0 Chen =.881 " 3C 2p53d 1P1 gnd ( Å) 3D 2p53d 3D1 gnd ( Å)! ' '(# '(% '(' '() * *(# 78.92:3-/;.<=.:12>:./83?@;5AB Fe XVII 3C/3D from the point of view of observational data and various calculations

19 Current Problems: Fe XVII Gillaspy et al Fe XVII 3C/3D from the point of view of laboratory data and various calculations

20 Current Problems: Ionization Balance Fractional Ion Population T=107K % Error in Ion Population T=107K C N O Ne Mg Al Si S Ar Ca Fe Ni 0 C N O Ne Mg Al Si S Ar Ca Fe Ni 30% errors on the ionization & recombination rates leads to ~30% errors in the ion population. However, at the limits of an ion s population, these errors are increased up to 60%.

21 Low Abundance Elements Flux (cts/s/kev) Tamagawa Ca XIX n= ±0.04 kev Tycho SNR observed with Suzaku XIS CCDs 5.48±0.02 kev Cr K Neutral Cr K 5.95±0.05 kev Mn K 5 6 Energy (kev) Neutral Mn K FeK Suzaku 100ks Tycho observation shows Mn and Cr fluorescence lines from partiallyionized material. Relevent atomic parameters had to be estimated. (Tamagawa+08) Badenes+(2008) considered model SNIa explosions with different neutron excesses and various classes of explosions For the progenitor of Tycho's SN, the data requires a near-solar or supersolar metallicity Badenes et al 2008

22 Wavelengths Mkn 421 Chandra LETG/HRC-S Flux (counts/0.0125å bin) Balucinska-Church & McCammon (1992) This work Hasoglu Lee et al 09 Wavelength (Å) Absorption edges and related features still need a lot of work

23 Fluorescent Line Data Bandler et al The fluorescent lines from radioactive sources are not simple Lorentzians, but complex combinations of many lines. Line widths measured by current calorimeters are dominated by the natural line widths which are not known for many useful elements! Hoelzer et al 1997

24 Conclusions Send lawyers, guns, and money We need a balanced program of focused Laboratory Measurements Theoretical Calculations Data Curation of Both Astro-H will usher in a new world of highresolution spectra, especially in the 2-10 kev band. We must be ready for it!